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Congenital cytomegalovirus (cCMV) is the most common congenital infection in the developed world. Reported prevalence varies between cohorts but is approximately 7 per 1000 births.1 About half of cytomegalovirus (CMV)-infected babies with clinically detectable disease at birth are destined to have significant impairments in their development, and cCMV infection is implicated in approximately 25% of all children with sensorineural hearing loss (SNHL).1,2 Meta-analysis shows that although long-term sequelae, especially SNHL, are more common in those with clinically detectable disease at birth, they are also found in 13% of those without clinical features attributable to CMV on initial examination.1 Despite the significant long-term impact of cCMV infection, there is limited evidence on which to base many treatment decisions in clinical practice. In an era of enhanced perinatal screening, fetuses and newborns are increasingly tested for CMV after abnormalities were detected during routine ultrasonography or maternal serology. Furthermore, otherwise “asymptomatic”, congenitally CMV-infected, newborns are being identified after detection of SNHL through newborn hearing screening programs. Because of earlier diagnosis, babies with cCMV now presenting to pediatricians differ from those primarily included in clinical trials of treatment reported in the literature. A symposium was convened during the 2015 conference of the European Society of Paediatric Infectious Diseases to discuss the current management of cCMV. In attendance were clinicians from throughout Europe, many of whom are involved in policy for cCMV for their region/country. This article summarizes the discussions at this meeting alongside the evidence informing them. A balanced perspective of the controversies in this area is presented and areas of consensus highlighted. Finally, where evidence is lacking, suggestions are made for future research efforts to address areas of unmet medical need. The authors acknowledge the coexisting need for studies on the management of babies with symptoms consistent with cCMV, but in whom this diagnosis cannot be firmly established, and of those with symptomatic postnatal CMV infection; this article does not, however, address these groups. The internationally accepted GRADE system for evaluating evidence has been used to illustrate points where relevant (Table 1).3TABLE 1.: Grade System of Evaluating Evidence3DEFINITIONS OF SYMPTOMATIC DISEASE Classically, cCMV infection is categorized as “symptomatic” or “asymptomatic” at birth. Differing definitions and opinions on what constitutes “symptomatic” CMV infection, however, makes interpreting the literature challenging. Indeed, some of the largest cohort studies include babies with SNHL at birth in the group described as being “asymptomatic” because no “clinically apparent disease” was detectable during newborn examination.4 In modern healthcare systems, whereby cCMV is increasingly detected through screening for other conditions, alongside increased accessibility of investigations, such as magnetic resonance imaging (MRI), the traditional dichotomy between clinically “apparent” and “inapparent” disease is becoming less meaningful. Table 2 summarizes the accepted clinical features of cCMV disease with those symptoms detectable on newborn examination listed separately to those detectable only if specific investigations are conducted, for example, when cCMV is already suspected.5–8TABLE 2.: Possible Signs and Symptoms in Children With Congenital CMV5–8Full Consensus Within This Expert Group Was That 1. For the purposes of research and publication, newborns identified as having cCMV disease after abnormal clinical examination at birth (such as microcephaly, small for gestational age (SGA), widespread petechiae, hepatosplenomegaly) should be differentiated from those babies identified through screening or investigation for other disorders, for example, those tested for CMV after known/likely maternal infection or abnormal newborn hearing screening. This differentiation would allow for more accurate assessment of the prognostic value of individual manifestations of “symptomatic” disease on longer-term outcomes as already shown in other publications.9 2. “Symptomatic” cCMV should be considered as “severe,” “moderate” or “mild” disease. a. “Mild” disease includes those with isolated (1 or 2 at most), otherwise, clinically insignificant or transient findings, such as petechiae, mild hepatomegaly or splenomegaly or biochemical/hematologic abnormalities (such as thrombocytopenia, anemia, leukopenia, borderline raised liver enzyme abnormalities or conjugated hyperbilirubinemia) or SGA (defined as weight for gestational age <−2 standard deviations) without microcephaly. b. “Severe” disease includes those with central nervous system (CNS) involvement (abnormal neurologic or ophthalmologic examination, microcephaly or neuroimaging consistent with cCMV disease [such as calcifications, moderate to severe ventriculomegaly, cysts, white matter changes, cerebral or cerebellar hypoplasia, hippocampal dysplasia, neuronal migration abnormalities])10 or with life-threatening disease. The Majority Agreed That 2b. “Severe” disease also includes babies with evidence of severe single-organ disease (including those with clinically significant liver enzyme abnormalities [liver “failure”] and marked hepatosplenomegaly) or those with significant multiorgan involvement. Babies with transient or otherwise clinically insignificant abnormalities (ie, the babies are not “sick”) that resolve spontaneously over a few weeks are not included in this group even if these abnormalities are multiple. 2c. A further group exists that may be considered to have “moderate” disease. This group is heterogeneous and includes, for example, those with persistent (eg, more than 2 weeks duration) abnormalities of hematologic/biochemical indices or more than 2 “mild” disease manifestations (as listed earlier). Because of lack of evidence, full consensus could not be reached on how to approach this group, and treatment decisions are currently made on a case by case basis. Development of a validated clinical scoring system for disease severity at presentation and risk of sequelae would be beneficial for both counseling parents and informing treatment decisions. 3. Defining CNS involvement a. It remains uncertain whether some, nonspecific findings detected on cranial ultrasound (CrUSS) and MRI (particularly isolated lenticulostriatal vasculopathy [LSV]) constitute clinically significant CNS disease. LSV has been detected in 0.4%–5.8% of all neonates undergoing an ultrasound, and only 5% has been associated with cCMV.11,12 Some have suggested isolated LSV as a marker of risk for SNHL.11 Others have found only more extensive neuroimaging abnormalities to be of prognostic value.13,14 The majority at this meeting would not consider LSV in isolation to be a notable CNS manifestation of disease. It is suggested that neuroradiologic abnormalities not known to be clearly associated with CMV disease and adverse outcomes are discussed with a suitably experienced neuroradiologist, particularly, if the results of these discussions might influence treatment decisions. b. The exact pathophysiology of SNHL is not clear but is likely secondary to infection and degradation of sensory structures within the inner ear.15,16 It is therefore debated whether isolated SNHL should truly be considered a CNS manifestation of infection and, as a consequence, whether such children should be considered comparable to those with CNS disease included in published clinical trials. No studies have addressed this specific population, but a nonrandomized cohort study observing the effects of valganciclovir in isolated SNHL is in progress (clinicaltrials.gov NCT02005822). The majority of experts at this meeting would categorize babies with isolated, confirmed SNHL in the “severe”/CNS group because bilateral SNHL is not only associated with likely long-term impairments but was also included in the criteria for recruitment in the only randomized controlled trials (RCTs) in cCMV. However, consensus was not reached because the spectrum of hearing loss is wide, and treatment of isolated SNHL has not been evaluated in any RCTs. WHEN SHOULD TESTING FOR CONGENITAL CMV BE CONSIDERED? Indications for testing for cCMV are based on the presence of one or more of the most frequently observed clinical features (Table 3).17 Unfortunately, predictive values for each of these features are not available.TABLE 3.: Clinical Features That Should Lead to Testing for Congenital CMVFull Consensus Within This Expert Group Was That Testing for cCMV Should be Performed in 1. Fetuses with ultrasound/MRI imaging consistent with cCMV disease (by appropriately timed antenatal testing of amniotic fluid).18 (Quality C, Level 1) 2. Newborns where there is a maternal history of suspected primary CMV infection during pregnancy. If antenatal testing of amniotic fluid has been conducted, it is suggested that cCMV infection should still be confirmed at birth because both false-positive and -negative results have been reported.18 (Quality C, Level 1) 3. Newborns with signs/symptoms consistent with cCMV disease (see Table 2; including those with findings consistent with cCMV on antenatal imaging). (Quality B, Strength 1) 4. Children with confirmed SNHL.16 Systems need to be established to ensure testing for cCMV occurs, where possible, in the first 21 days of life because dried blood spot (DBS) are not always readily available for testing (see below). (Quality B, Strength 1) The Majority Agreed That 5. Newborns who are SGA should not routinely be tested. Studies in SGA newborns have shown the prevalence of cCMV to be 0%–5.2%.19–22 However, the majority of studies report a prevalence of 1.4%–1.8%, which is not significantly higher than the prevalence of cCMV in the general population. Therefore, evidence is insufficient to justify screening all newborns with isolated SGA for cCMV. None of these studies distinguish between asymmetrical (with normal head circumference) and symmetrical SGA, but when head circumference was mentioned, most SGA babies with cCMV had microcephaly (head circumference <−2 standard deviations).21,22 Because of this, and the poor prognostic outcome of children with cCMV and microcephaly, many present at this meeting test those babies with symmetrical SGA but not those with preserved head growth.14(Quality C, Strength 2) 6. Prematurity. Evidence that premature babies have a higher incidence of cCMV is limited.20,23 Testing extremely premature babies (<28 weeks gestational age) at birth does, however, assist in differentiating between congenital and postnatal infection. This may be very helpful in guiding the management of these babies that are particularly vulnerable to symptomatic postnatal infection. However, consensus was not reached regarding practice in this area, with cost being a factor among other considerations.24 (Quality C, Strength 2) 7. Testing of babies born to mothers who are known to be CMV seropositive at the establishment of pregnancy. Although maternal nonprimary CMV infection is known to be important when considering the overall burden of cCMV disease, testing all babies born to these women, particularly in populations with high maternal seroprevalence, is tantamount to universal neonatal screening.25,26 Identifying women with nonprimary CMV who are at highest risk of transmitting infection to their fetus remains elusive. It was agreed that individual case discussion and local policy should therefore dictate practice in this area. Further research is clearly needed. LABORATORY DIAGNOSIS OF CONGENITAL CMV INFECTION Testing for cCMV using CMV polymerase chain reaction (PCR) in urine is highly reliable: sensitivity is 100% and specificity 99%.27 One negative urine specimen in a neonate is therefore sufficient to exclude infection, and repeat sampling is not necessary. After 21 days, a urine positive for CMV could be because of CMV acquired postnatally from, for example, passage through the birth canal or through breast milk. As CMV PCR techniques are becoming more sensitive, earlier testing, before the age of 14 days, is recommended.27 CMV PCR testing of saliva is an alternative and is easy to perform. Samples should be taken immediately before feeding in breastfed newborns, and confirmed with urine, as false-positive results have been reported.28–31 PCR assay of neonatal DBS can be performed retrospectively in an attempt to diagnose cCMV after the first 21 days of life. is in but is highly on the techniques used and the being a negative DBS PCR be used to exclude a diagnosis of Consensus Within This Expert Group Was That 1. Testing for cCMV should be performed using a CMV PCR of urine within 21 days of birth but within 14 days of birth (Quality B, Strength 2. PCR testing can be an but a positive should be confirmed using urine (Quality B, Strength 3. After the age of 21 days, CMV PCR of DBS can be used to diagnose cCMV sensitivity is and a negative test cannot be used to exclude a diagnosis of cCMV (Quality B, Strength A DIAGNOSIS OF CONGENITAL CMV INFECTION After a diagnosis of cCMV infection has been investigations are to the of disease and to assist with discussions regarding and Consensus Within This Expert Group Was That 1. The investigations are in any in whom a diagnosis of cCMV is for the manifestations of disease (Table blood liver (Quality Strength 1) testing some screening such as are not sufficient to central hearing loss in (Quality Strength 1) (Quality Strength 1) 2. If imaging to is to be MRI is the neuroimaging MRI can be performed in neonates without the need for and both highly and of the of which (Quality C, Strength 1) 3. MRI should be performed in babies with clinically detectable neurologic findings or The Majority Agreed That 4. MRI should be performed in any babies with cCMV and evidence of CMV disease (see Table (Quality C, Strength 1) 5. CMV PCR should be performed in blood at studies have shown the of CMV to be associated with long-term and this may be when evaluating babies without any other manifestations of cCMV CMV PCR should not, however, be used to cCMV infection the of CMV in blood has been described even in babies with severe cCMV (Quality C, Strength 2) 6. of fluid No current evidence examination of as of routine Studies have shown detectable CMV in and such as a poor However, have shown no prognostic value from in the clinical Despite this lack of evidence, there was a majority that although a area of for future should not be performed routinely in babies with cCMV infection (Quality C, Strength a Agreed That 7. MRI should be performed in all Although there is no evidence that MRI prognostic to in those without evidence of CMV disease at birth, some that it is to MRI in all babies because can be identified as with (Quality Strength No are currently for the treatment of cCMV. Although many case and cohort studies have reported on treatment for cCMV, there are results from only 2 The first of these studies evaluated treatment in neonates of gestational age weeks and clinically apparent disease in the newborn with evidence of CNS disease (including microcephaly, abnormal indices for hearing and hearing and outcomes were but there was significant loss to A more to treatment with valganciclovir and included babies with any evidence of symptomatic (including cCMV babies however, had isolated, mild clinical and in the treatment group had isolated SNHL A on both hearing and outcomes was shown with the treatment The treatment of hearing outcomes most in those with CNS involvement. of was only however, for hearing as to hearing is of and only for CNS involvement. the of some features of cCMV disease in published alongside the of hearing loss and in SNHL reported in cCMV, it is even more to any regarding treatment from Clinical trials to not, evidence on which to base treatment decisions for many of the presenting to clinicians in clinical practice. Table on which should be treatment after a risk discussion with the This and associated areas where consensus was discussion the treatment of babies with less severe cCMV disease and whether the shown in the treatment was sufficient to justify such a of Although clinical findings such as SGA and have been shown in cohorts to risk for SNHL, more of that these findings in isolation are associated with outcomes in babies presenting without other manifestations of symptomatic on the or of symptoms treatment remains and it is therefore that clinicians discuss treatment and with an in this of Consensus Within This Expert Group Was That 1. Babies with evidence of CNS disease should treatment (Quality Strength should be for (Quality B, Strength 2. Babies with no findings consistent with CMV disease should not treatment because no evidence exists to treatment in this group (Quality Strength to 3. Babies with evidence of life-threatening disease or severe single-organ disease or multiorgan involvement should Although evidence is particularly for life-threatening disease, consensus was that treatment should be considered in this group (Quality B, Strength Consensus could not be reached on of treatment in this 4. valganciclovir is now the of should be used in babies to or where is uncertain (Quality Strength The Majority Agreed That 5. Babies with “mild” cCMV disease (as should not No studies have clearly addressed treatment in this present at this meeting would not, babies with or 2 isolated or clinically manifestations of disease (Quality C, Strength 6. Babies with “moderate” cCMV disease (as earlier). Evidence for babies with but not manifestations of disease (including without significantly raised liver is It that these are discussed on a with a with of babies with cCMV (such as a disease (Quality B, Strength 7. of isolated The majority at this meeting would include SNHL at birth in their for treatment because this was in the criteria for treatment in RCTs. Furthermore, the of treatment is in hearing than hearing with outcomes reported in studies (with likely was not, however, and it is that no have addressed treatment in this group of babies who are now identified through newborn hearing screening C, Strength and Although valganciclovir is now treatment in most it is currently whether valganciclovir areas as as where should be (eg, CNS or inner because no studies have the 2 In those with severe disease, particularly if is by some in of treatment can be (Quality C, Strength in without CNS In those in whom the is taken to the majority would for However, there was no consensus on this in of the shown for treatment in the only (Quality B, Strength babies than of children has not been addressed in any although it is that the is also not evidence case of small of babies the newborn have reported Babies found to have SNHL after hearing screening at birth not have a diagnosis of cCMV confirmed the of for No consensus was reached on how it might be to treatment in this or in the of hearing are currently evaluating the of treatment in children with cCMV and SNHL (clinicaltrials.gov and which may this for the newborn Strength OF of the less babies to the effects of currently available is frequently observed during treatment in This is reported less with valganciclovir than with with during the first of with no increased observed after weeks in those randomized to treatment with in the only evaluating The of valganciclovir also the burden of and risk of and central observed during treatment with has been reported in to of those with and in a In the most study of treatment with liver was but this was clinically significant when with In all abnormal and after effects have not been evaluated in neonates with or studies the risk of and Although this has not been observed in to parents should be these particularly when considering treatment in those in which has not been clearly No adverse long-term effects have been in a small cohort of babies in neonatal studies and to OF Table summarizes a for babies for cCMV. are based on the and from the published and to are no to however, have a when is a (eg, in those with or where there are treatment Consensus Within This Expert Group Was That treatment is babies should have weight and to of (see Table Strength 1) treatment is parents should be both the known and effects of treatment with current (Quality Strength for no published Although there are of treatment no cohorts have been to this to be evaluated in during life. possible, children treatment be a to a Agreed That Some report to assist in decisions regarding and detection of however, most experts at this meeting not this is not by any and of after treatment is with no with long-term outcomes (Quality Strength If is after it is suggested that parents are of the that be detectable and that this is of Table summarizes of babies with cCMV and The for is based on long-term studies of SNHL in is suggested during the first 2 of life because this is the of highest risk for of hearing loss and a for detection of SNHL during this is also most likely to long-term should however, because in hearing throughout (Quality B, Strength is suggested at and 2 of age with This is not, however, routinely in all and there is no in this group, although detection of impairments is agreed to be is at children can in those with clinically detectable disease at birth, but not in those because in has been observed in this group (Quality C, Strength should be for where these (see cCMV are not parents of children with hearing loss may from for those with hearing FOR Clinical trials treatment of those with more manifestations of clinically detectable disease at birth and those with isolated Clinical studies of antenatal to of infection and cCMV disease infection is to cCMV should it clear how those included were identified (ie, babies presenting with clinically detected babies identified through antenatal or postnatal screening including hearing screening or after further investigation of such as thrombocytopenia, found when blood sampling is performed for other Development of clinical to categorize severity of disease and babies with findings of and associated outcomes to assist counseling of Studies of particularly and value with to long-term impairments particularly in those without clinically detectable disease at birth through studies cCMV Clinical trials of alternative treatment and when It that a of treatment be beneficial in babies with such clinical manifestations of disease and likely burden and The of both and of long-term outcomes would of future and more accurate counseling and children treatment should be in a to for any long-term effects of of risk for maternal particularly, in those mothers with known to CMV As at the this article the consensus of a group of with a in cCMV. It that of practice is based on limited but areas where there is consensus have shown cost of screening at birth for cCMV, although these are by the raised in this article regarding of of treatment and agreed treatment in It be to address many of the research raised through the significant and long-term alongside in such studies when treatment is being more accurate on disease manifestations and treatment outcomes in alongside maternal however, treatment as shown very for the management of This a approach to initial definitions of and which is currently being addressed by a of clinicians with an in this area through both and European such as Paediatric European for of Infectious the European Congenital CMV and European Society of Paediatric Infectious Diseases and European Society for Clinical It should also be that this article on postnatal of diagnosis and is an associated and need for alongside and to address in of antenatal It is that through such progress be made in infection and disease in newborns and children with cCMV. The children and their who have for and who on a to and consistent including those parents who are involved with other parents through local or including not CMV

Accepted: 27 July 2001 Introduction 1 Purpose of the guidelines 2 Basing recommendations on evidence 3 Use of evidence published as abstracts 4 Implications for research 5 Use of surrogate marker data 6 Issues concerning design and analysis of clinical trials 6.1 Trial designs 1.6.2 Methods of analysis 1.6.3 Intention to treat and on treatment analyses 1.6.4 Equivalence 1.6.5 Cross-study comparisons: presentation of data 7 Adverse event reporting 0 When to start treatment 1 Primary HIV infection 2.1.2 Recommendations for starting treatment in PHI 2 Symptomatic HIV infection 3 Asymptomatic HIV infection 2.3.1 Recommendations for starting treatment in established HIV infection 0 What to start with 1 Choices of initial therapy 2 Which HAART regimen is best? 3 Recommended initial HAART regimens 3.3.1 Two NRTIs plus one or two PIs 3.3.2 Two NRTIs plus an NNRTI 3.3.3 Advantages and disadvantages of NNRTIs 3.3.4 Three NRTIs 3.3.5 Advantages and disadvantages of three NRTIs 4 Choice of NRTI backbone for initial therapy 5 Recommendations for initial therapy 0 Issues concerning antiretroviral use 1 Adherence 2 Toxicity 4.2.1 Lipodystrophy 4.2.2 Management of lipodystrophy 4.2.3 Mitochondrial toxicity and lactic acidosis 0 Changing therapy on first virological failure 1 Initial failure 5.1.1 Viral load blips 5.1.2 Sustained viral load rebound 2 Changing therapy 5.2.1 Recommendation for changing therapy 3 Failure of two NRTIs plus a PI 4 Failure of two NRTIs plus an NNRTI 5 Failure of triple NRTI therapy 0 Therapy after more than one previous failure ('salvage' therapy) 1 Definition of salvage therapy 2 Measuring the success of salvage regimens 3 Principles of optimizing salvage success 4 Salvage therapy in PI experienced patients 5 Salvage therapy in NNRTI experienced patients 6 Salvage therapy in patients with multiple class resistance 7 Structured treatment interruption 6.7.1 STI to enhance immune responses 6.7.2 STI for reducing drug exposure/toxicity 6.7.3 STI to induce repopulation with wild type virus 6.7.4 Alternative approaches to treatment failure 6.7.5 Conclusions 8 Viral fitness 9 New therapies 10 Stopping therapy long term 11 Recommendations for subsequent virological failure (third or more regimen) 0 Resistance testing 0 Therapeutic drug monitoring 1 Plasma levels 8.1.1 Low plasma drug levels correlate with virological failure 8.1.2 High plasma drug levels may predict toxicity 2 Adherence 3 Drug interactions 4 Special groups 5 Problems with TDM 6 The way ahead 0 Haemophilia 0 Co-infection with HIV and hepatitis 1 Co-infection with HIV and hepatitis B 10.1.1 Background 10.1.2 Assessment of HBV infection in HIV-infected individuals 10.1.3 Management of HBV in HIV-infected individuals 10.1.4 Co-infection and the use of antiretroviral therapy 2 Co-infection with HIV and hepatitis C (HCV) 10.2.1 Background 10.2.2 Assessment of HCV infection in HIV infected individuals 10.2.3 Natural history of HCV in HIV infection 10.2.4 Management of HCV in HIV-infected individuals 10.2.5 Co-infection and the use of antiretroviral therapy 0 Issues not addressed in these guidelines 1 Pregnancy 2 Paediatrics 3 Post-exposure prophylaxis for healthcare workers 4 Age 5 Sex-based differences 0 BHIVA IAS-USA comparisons 0 References 0 Conflict of interest List of tables Table Grading of recommendations and levels of evidence Table When to start treatment: summary of recommendations Table Choices of initial therapy: summary of recommendations Table Currently available protease inhibitors (PIs) for initial treatment Table Currently available non-nucleoside reverse transcriptase inhibitors (NNRTIs) Table Agents to be used in combination with dual NRTI background Table Promoting adherence: issues to consider Table Management of lipids with specialist advice Table Management of glucose intolerance with specialist advice Table Changing therapy on first virological failure: summary of recommendations Table What to change to after first virological failure: summary of recommendations Table Potential objectives of structured treatment interruptions (STI) in different clinical settings Table Recommendations for use of HIV drug resistance tests Table Proposed indications for TDM Table Management of hepatitis C (HCV) infection in co-infected individuals Table Recommendations for starting antiretroviral therapy in adults: 2001 The BHIVA executive is committed to producing updates on the antiretroviral treatment guidelines for adults on a regular basis. Over a 1- to 2-year period much can change in clinical practice as new scientific evidence is published. To reflect these changes the guidelines have been extensively revised and some sections expanded and new sections added. The principles of consensus that overarched the previous guidelines [1, 2] were upheld in the production of this, the latest version. We believe it is important that the process by which the guidelines have been revised is made clear. Each section of the guidelines was designated to two members of BHIVA, and the Executive Committee have taken on the bulk of this work. The members were asked to revise the guidelines in line with new evidence that had been published either in peer reviewed journals or as peer reviewed abstracts at international meetings. The authors were asked to consult widely with colleagues and co-opt other BHIVA members if need be. Guidelines for the treatment and management of HIV infection have been produced in a number of countries in Europe, as well as in Australia and the USA [3-6]. The BHIVA guidelines have a number of important roles which are: To promote a uniformly high standard of care in all HIV treatment centres in the UK. To set out the strengths, weaknesses and relevance of recent research findings. To assist in discussions between purchasers and providers regarding funding for HIV/AIDS diagnostic testing, care and treatments. To act as a basis for clinical audit within clinical governance. To act as a source of reference on AIDS treatments for those physicians caring for patients infected with HIV. To act as a source of reference for HIV-positive people. These guidelines should not be seen as a substitute for research, nor as a manual for managing an individual, and should be interpreted and applied sensibly and appropriately. While the guidelines attempt to represent the current state of knowledge it is inevitable that, as HIV/AIDS is a rapidly evolving medical field, new data will change therapeutic choices and preferences. Consequently, the guidelines will require modifications as important new data emerge and the website version will be amended at regular intervals to reflect these data. Revisions are planned annually. Recommendations made within these guidelines have been graded according to the level of evidence on which they are based (Table 1). Recommendations range from 'essential' to 'not recommended' and the quality of evidence from 'at least one randomized trial with clinical endpoints' through to 'expert opinion'. They are to be found in parentheses in the document, for example (AII). The committee used an evidence-based medicine approach to produce these guidelines. In reality, if only the most reliable form of clinical evidence was taken into account (i.e. results of one or more randomized controlled trials with clinical endpoints), it would be impossible to formulate these guidelines. Many important aspects of clinical practice remain to be formally evaluated and very few trials with clinical endpoints are ongoing or planned. Results from clinical trials with viral load and CD4 count changes as endpoints were included as, in many instances, they are the only source of evidence. However, most such trials have been performed in order to obtain drug approval and are not ideally suited to addressing questions of clinical usage. The most significant drawbacks of such trials are their short duration and the lack of follow-up data on patients who switch therapy. In most cases the only available data on long term outcomes are from routine clinical cohorts. While such cohorts are representative of routine clinical populations, the lack of randomization to different regimens means that comparisons between the outcomes of different regimens are highly susceptible to bias [7, 8]. Expert opinion forms an important part of all consensus guidelines; however, this is the least valuable and robust form of evidence. The authors of these guidelines recognize that there is often a considerable time lag between initial presentation of important data, whether orally or in abstract/poster format, and full publication. Consequently, there is danger in relying on data that have not been subjected to formal peer review and published in full. We have therefore avoided citing any research findings that appeared only in abstract format more than 3 years ago (i.e. before mid 1998). Unless guidelines are interpreted and applied cautiously and sensibly, valuable research initiatives that might improve standards of care will be stifled. It would be wrong to suggest that certain clinical controlled trials would be unethical if they did not conform to the guidelines, especially when these guidelines are based mainly upon expert opinion rather than more reliable evidence. The National Health Service (NHS) executive has stated that clinical guidelines cannot be used to mandate, authorize or outlaw treatment options [9]. CD4 cell counts and plasma viral load are used as markers of the biological activity of antiretroviral therapy in Phase I and II trials. Reduction in viral load leads to a rise in peripheral blood CD4 count, with greater rises being seen in those with greater and more sustained viral suppression [10]. Changes in these markers in response to therapy are strongly associated with clinical response [11-14]. CD4 counts measured in people on antiretroviral therapy have been associated with a risk of AIDS defining diseases no higher than that expected in untreated individuals with similar CD4 counts [15-19]. The CD4 count is a better indicator of the immediate risk of AIDS defining diseases than the viral load in those on antiretroviral therapy [20]. Favourable responses to therapy, i.e. a decline in plasma HIV-1 RNA and increase in CD4 cell counts, have led to accelerated licensing of antiretroviral agents since it is impracticable to wait years for large clinical endpoint trials to be completed before drugs are approved [11, 12, 21]. Drugs are given full approval on the basis of trials lasting 48 weeks and, in some countries, accelerated approval based on data to 16 weeks. Most clinicians would agree that a drug licensing policy based on surrogate markers is reasonable and humane. However, it should be remembered that CD4 count and viral load responses do not precisely reflect the expected clinical outcome and are not perfect surrogates of the clinical response [22-24]. This is because the drugs have other effects with clinical consequences besides those reflected in viral load and CD4 count changes. The relatively short length of trials designed to obtain drug approval means that, at the time of licensing, little may be known about the drugs' long term consequences. Most antiretroviral drug trials are performed by pharmaceutical companies as part of their efforts to obtain licensing approval and the designs are often not ideally suited to deriving information on using the drugs in clinical practice. Besides the short duration of follow-up, their key limitation is the lack of data on outcomes in people who change from the original randomized regimen, along with a description of what those new regimens are. The results are therefore only clearly interpretable as long as a high proportion of participants remain on the original allocated regimens. Clinical questions about which drugs to start with or switch to require longer term trials that continue despite changes to the original treatment. From a clinical perspective it makes no sense to ignore what happens to patients after a regimen has been discontinued. Moreover, use of a given drug can affect outcomes long after it has been stopped. For example, it may select for virus resistant to drugs not yet encountered or cause toxicities which overlap with those caused by other drugs. However, interpretation of such trials is not straightforward, and account must be taken of which drugs were used subsequent to the original regimen in each arm. Planned or ongoing trials adopting such an approach include Initio, Community Programs for Clinical Research on AIDS (CPCRA)′s FIRST, ACTG 384 and the three nation OPTIMA trial [which is being run in the UK by the Medical Research Council (MRC)]. Study design may significantly influence the discontinuation rate of trial drugs. An open trial design may result in higher levels of discontinuation from what is perceived to be the least effective regimen, while a double blind, placebo controlled study may reduce adherence in all groups because of the large pill burden. It is also important to recognize that controlled clinical trials provide an optimal treatment setting but results from the use of regimens in clinical practice are usually not as good. Several methods have been used to analyse viral load and CD4 count responses, including the change from baseline at a given time and the time-weighted change from baseline or the area under the curve (AUC). For virological response, however, the most common approach relates to whether the viral load is below a certain level, usually 50 HIV-1 RNA copies/mL, which is the approximate lower limit of quantification for most viral load assays in routine use. The proportion of people with viral load < 50 copies/mL at a given time point is assessed. One reason for the choice of this outcome measure is that some studies have indicated that if this minimum level is not achieved then subsequent viral load rebound is more likely [25, 26]. However, when comparing treatment regimens, differences in viral load between treatment groups, provided levels are > 50 copies/mL, are highly predictive of subsequent differences in clinical outcome [27]. Restricting comparison to those with viral load < 50 copies/mL would not utilize other information contained in the viral load measurement. A related method of assessing response to an initial regimen is calculating time to virological failure. Virological failure is typically defined by failure to achieve viral suppression or viral load rebound after achieving < 50 copies/mL, but there is no consensus on precise definitions [21, 28]. Randomization in a trial ensures balance in prognosis between the treatment arms at baseline. Inability to assess outcomes for some patients can disturb this balance and create bias in the comparison between the treatment arms. In order to avoid risk of such bias, analysis by intention to treat includes outcomes for all randomized patients. For this purpose, it is necessary to continue collecting data on all patients even if they have switched from the original regimen. As this is rarely done, the intention to treat principle is maintained by imputing values for those patients who have dropped out of the trial. When the outcome is the proportion of people with viral load < 50 copies/mL at a given time point, the approach almost universally adopted is to assign > 50 copies/mL to all patients who have earlier switched therapy or have the viral load value missing for any reason. This is known as the missing = failure approach [29]. Such an approach implicitly equates failure of a regimen due to inadequate potency and/or viral drug resistance with inability to tolerate a regimen due to pill burden, inconvenience and/or adverse effects, even though the implications of these two outcomes are likely to be substantially different. This approach is often labelled conservative because it gives a minimum proportion < 50 copies/mL for any given treatment group over all possible approaches. However, the primary purpose of an endpoint is to compare treatment arms and, in this context, this approach is not conservative in any general sense. On treatment analyses consider outcomes only in those still receiving the original allocated treatment. In the context of the proportion of people with viral load < 50 copies/mL at a given time point, this makes little sense because therapy is switched in patients who experience viral load rebound during a trial. Given this management policy, the proportion of people remaining on the original regimen who have a viral load > 50 copies/mL will reflect the speed with which clinicians decide to switch therapy in response to the first viral load value(s) > 50 copies/mL. It is difficult to see how it provides a useful means to compare the efficacy of different regimens. Within the context of time to virological failure, the on treatment analysis may be more revealing. In situations where there is a high (> 25%) proportion of patients who do not have a viral load value at a given time point (except where this occurs due to staggered entry), interpretation is inherently difficult and no analytical approach is entirely satisfactory. Large numbers of patients are usually required to show equivalence between regimens (i.e. to demonstrate no or a small difference in response between treatments). Many surrogate marker studies are underpowered to demonstrate this. Stating that studies have shown no significant difference between the treatment arms is very different from saying that the arms show equivalence. Graphical representations that show overlapping increased CD4 cell counts or decreased viral loads in response to therapy may hide differences in efficacy between drugs. The confidence interval (CI) for the difference in outcome between treatment arms should be examined carefully in such studies. Lack of adherence to allocated regimens is an even greater issue in equivalence trials because an intention to treat analysis would tend to dilute the difference in outcome between treatment groups. Unless discontinuations and treatment changes during the trial reflect what would happen in clinical practice, the results from intention to treat analysis would be biased towards equivalence. It is tempting to compare results of individual drug combinations assessed in different trials. Such comparisons are, however, difficult to interpret because of differences in entry criteria (particularly with respect to viral load and CD4 cell counts), methods of analysis (e.g. intention to treat vs. on treatment), degrees of adherence and sensitivities of viral load assays. Many previously unsuspected side effects of antiretroviral therapy have been reported only after drug licensing. It is vital that prescribers report any adverse events as soon as possible so that these events are swiftly recognized. A by the the Committee for of and the in the UK for reporting adverse events to the treatment of HIV available antiretroviral of HIV infection is not likely to be possible The of treatment is to and improve quality of by suppression of virus for as long as The three groups of treatment patients for treatment guidelines are required are: patients with primary HIV patients with HIV infection and patients with HIV or The recommendations are in Table is one study of in primary HIV infection and it As yet there is no evidence of clinical from any study of treatment of PHI with treatment it is the of PHI may represent a for therapeutic It is likely that, at the time of there is a of the of the virus with the virus in the viral to different cell may be and the to an immune response is usually greater than it is the treatment of PHI may HIV immune responses and it has been that long term may A of triple drug therapy regimens to viral in the and for the of patients within a few of PHI studies have that after PHI there is a and CD4 HIV response This is in to infection with the of long term the HIV CD4 response is These CD4 responses may be important in an Such immune responses to be maintained in people with antiretroviral therapy after PHI and represent the biological evidence that treatment at this time might be data suggest that there is more and immune in patients starting therapy during PHI than in those starting is still no to the of whether treatment at such an will influence the longer term of viral with no of after of antiretroviral therapy has in a few patients very soon after PHI The of drugs that are known to CD4 such as and A in the suppression of viral and of CD4 responses in this setting is and data a possible for treatment interruptions in the immune response and reducing the virological set point in patients very during PHI have found that therapy during PHI had no upon the set point that would have been expected in the of any treatment Given the lack of it reasonable to consider ideally within a clinical trial. These of treatment during PHI should be by the known of including lipodystrophy despite suppression of plasma viral HIV may with an associated risk of of drug resistance or of drug resistant virus Given that the optimal duration of therapy is it should be that treatment may be required even when during The of long term adherence to available regimens cannot be One study has that many infected patients have the infection from who were infected with HIV. and treatment of PHI might have some on reducing HIV if treatment is not during there are many of HIV These include and monitoring of primary drug and and the of HIV should be to patients with PHI who may to a range of healthcare It is very important at the time of PHI that patients and physicians the most based on the data data are available to the therapeutic the first choice is to patients into a clinical where The biological that treatment may be for the immune should be of adherence to long term therapy, toxicity and of treatment is not within a few of a may be The to or continue may be reviewed in the of evolving data or It is that many patients will not to be at this time and, because of the this choice should be and be patients are a clinical trial a regimen for HIV infection should be used section patients with and/or HIV infection with a CD4 count < or who have been with AIDS or HIV related the possible of or at any CD4 count, should start therapy. This is because of the high risk of may cause or be are no ongoing or planned controlled studies that the time to start therapy guidelines are therefore based upon previous studies of and data from large clinical cohorts. the quality of evidence is relatively opinion is on this In the patients are with HIV infection at a Over with a CD4 count of < and, the vs. is to The on when to start treatment will be by two the short term risk of AIDS to treatment and the efficacy of starting treatment at CD4 from studies with short term follow-up have that patients who therapy when the CD4 count is < have an increased with those this level, but were to show any difference in those starting at any CD4 level > However, data from other studies suggest that patients who therapy the CD4 count is < may have a similar virological and response to those starting This is in to data from clinical studies the of baseline CD4 response on therapy may not be the for all drugs One study has that patients who therapy with a CD4 count > were likely than those who to experience or of such results is not these studies do not the of when to they do in the of therapy as measured by in CD4 Clinical event by baseline CD4 count mainly reflect the of the before starting therapy, not the of therapy. This is in to the viral load when changes to < or < 50 copies/mL can be almost entirely to the of therapy. It is not to that because the event rate in the CD4 group is higher than in the > CD4 the therapy has in the lower CD4 count this provide any evidence of therapy at CD4 counts > these data suggest that, patients should start therapy before the CD4 count has to < A number of need to be when with each individual (Table with a rapidly CD4 count (e.g. > on have an increased risk of CD4 cell count decline to < in the 6 This group many be for of therapy relatively earlier within the CD4 count range guidelines have starting therapy relatively in patients with a high plasma viral load [1, are three viral load should about when to start antiretroviral therapy. a viral load > copies/mL a rate of decline in CD4 this level of viral load is an risk for subsequent and However, these data are from an before the of highly antiretroviral therapy and may not be recent studies have that baseline viral load not predict subsequent of the baseline CD4 count after starting therapy. some data have that the baseline viral load the virological response to treatment in some studies This is not however, for all cohorts or all drug regimens and the efficacy of combinations in patients with higher viral being a better indicator of what to start with rather than when to It should be the CD4 count that about when to with a rapidly CD4 count or high viral load may be for earlier therapy the range of CD4 to that the CD4 count not to < In patients with

Table of contents 1.0 Introduction 2.0 Methodology 2.1 Basing recommendations on evidence 2.2 Implications for research 2.3 Use of surrogate marker data 2.4 Issues concerning design and analysis of clinical trials 2.4.1 Trial designs 2.4.2 Viral load outcome measures 2.4.3 Noninferiority 2.4.4 Cross-study comparisons and presentation of data 2.5 Adverse event reporting 3.0 When to start 3.1 Primary HIV infection 3.2 Established HIV infection 3.3 Patients with a CD4 count >350 cells/μL 3.4 Comorbidities 4.0 What to start with 4.1 Which HAART regimen is best? 4.2 Recommendations 4.3 Two NRTIs plus an NNRTI 4.3.1 Efavirenz (preferred regimen) 4.3.2 Nevirapine 4.4 Two NRTIs plus a boosted PI 4.4.1 Boosted lopinavir 4.4.2 Boosted fosamprenavir 4.4.3 Boosted saquinavir 4.4.4 Boosted or unboosted atazanavir 4.4.5 Boosted darunavir (unlicensed for naïve patients) 4.5 Three NRTIs 4.6 Choice of two NRTIs 4.7 Coformulated two NRTIs 4.7.1 Tenofovir/emtricitabine (Truvada) 4.7.2 Abacavir/lamivudine (Kivexa) 4.7.3 Zidovudine/lamivudine (Combivir) 4.8 Other two-NRTI combinations 4.9 Conclusions 5.0 Virological failure: after first-line treatment 5.1 Viral load blips 5.2 Sustained viral load rebound 5.3 Changing therapy 5.4 Virological failure with no resistance 5.5 First-line virological failure with PI mutations 5.6 Virological failure with NNRTI mutations 5.7 Virological failure with NRTI mutations alone 6.0 Subsequent virological failure 6.1 The patient with therapy options 6.2 The patient with few or no therapy options: continue, interrupt or change therapy? 6.2.1 Continuing the failing regimen 6.3 Treatment interruption 6.4 Change 7.0 New drugs 7.1 Etravirine (TMC-125) 7.1.1 Pharmacokinetics 7.1.2 Resistance 7.1.3 Efficacy, safety and tolerability 7.2 Maraviroc 7.2.1 Pharmacokinetics 7.2.2 Resistance 7.2.3 Efficacy, safety and tolerability 7.3 Integrase inhibitors 7.3.1 Raltegravir in treatment-experienced patients 7.3.2 Resistance 7.3.3 Raltegravir in treatment-naïve patients 8.0 Treating patients with chronic hepatitis B or C 8.1 Hepatitis B 8.1.1 When to treat 8.1.2 What to treat with 8.2 Hepatitis C 8.2.1 When to treat 8.2.2 What to treat with 8.2.3 Avoiding antiretroviral hepatotoxicity 8.2.4 Recommendations 9.0 Guidelines for the management of metabolic complications in HIV infection 9.1 Lipid abnormalities 9.1.1 Evaluation of risk 9.1.2 Which calculator to use 9.1.3 Treatment of lipid disorders 9.1.4 Switching ART 9.1.5 Lipid-lowering treatments 9.1.6 Which agents to use 9.2 Insulin resistance and diabetes 9.2.1 Recommendations for assessment and monitoring of insulin resistance 9.2.2 Treatment 9.3 Prevention and management of lipodystrophy 9.3.1 Assessment of lipodystrophy 9.4 Management of lipoatrophy 9.4.1 Surgical intervention 9.5 Lipohypertrophy 9.5.1 Prevention 9.5.2 Pharmacological intervention 9.5.3 Surgical therapy 9.6 Lactic acidosis and hyperlactataemia 10.0 Recommendations for resistance testing 10.1 Treatment-naïve patients 10.2 Treatment-experienced patients 10.3 Key principles in the interpretation of antiretroviral resistance in treatment-experienced patients 10.3.1 General recommendations 11.0 Adherence 11.1 Assessing adherence 11.2 Interventions to support adherence 11.3 Costs 12.0 Pharmacology 12.1 Drug interactions 12.2 Therapeutic drug monitoring (TDM) 12.3 Stopping therapy 12.4 Pharmacogenetics 13.0 HIV testing 14.0 Cost-effectiveness 15.0 Conflict of interest 16.0 References 17.0 Appendix The 2008 BHIVA Guidelines have been updated to incorporate all the new relevant information (including presentations at the 15th Conference on Retroviruses and Opportunistic Infections 2008) since the last iteration. The guidelines follow the methodology outlined below and all the peer-reviewed publications and important, potentially treatment-changing abstracts from the last 2 years have been reviewed. The translation of data into clinical practice is often difficult even with the best possible evidence (i.e. two randomized controlled trials) because of trial design, inclusion criteria and precise surrogate marker endpoints (see Appendix). The recommendations based upon expert opinion have the least good evidence but perhaps provide an important reason for writing the guidelines to produce a consensual opinion about current practice. It must, however, be appreciated that such opinion is often wrong and should not stifle research to challenge it. Similarly, although the Writing Group seeks to provide guidelines to optimize treatment, such care needs to be individualized and we have not constructed a document that we would wish to see used as a ‘standard’ for litigation. The Writing Group used an evidence-based medicine approach to produce these guidelines. In reality, if only the most reliable form of clinical evidence were taken into account (i.e. results of one or more randomized controlled trials with clinical endpoints), it would be impossible to formulate these guidelines. Many important aspects of clinical practice remain to be formally evaluated and very few trials with clinical endpoints are ongoing or planned. Many trials have been performed in order to obtain licensing approval for a drug. In many cases, they are the only source of evidence for comparing two drug regimens. However, the designs are not ideally suited to addressing questions concerning clinical use. The most significant drawbacks of such trials are their short duration and the lack of follow-up data on patients who switch therapy. In most cases, the only available data on long-term outcomes are from routine clinical cohorts. While such cohorts are representative of routine clinical populations, the lack of randomization to different regimens means that comparisons between the outcomes of different regimens are highly susceptible to bias [1,2]. Expert opinion forms an important part of all consensus guidelines; however, this is the least valuable and robust form of evidence. Unless guidelines are interpreted and applied cautiously and sensibly, valuable research initiatives that might improve standards of care will be stifled. It would be wrong to suggest that certain controlled clinical trials would be unethical if they did not conform to the guidelines, especially when these guidelines are based mainly upon expert opinion rather than more reliable evidence [3]. CD4 cell counts and plasma viral load are used as markers of the effect of antiretroviral therapy (ART). Reduction in viral load leads to a rise in peripheral blood CD4 cell count, with greater rises being seen in those with greater and more sustained viral suppression [4]. Changes in these markers in response to therapy are strongly associated with clinical response [5–9]. CD4 cell counts measured in people on ART have been associated with a risk of AIDS-defining diseases no higher than that expected in untreated individuals with similar CD4 cell counts [10–13]. The CD4 cell count is a better indicator of the immediate risk of AIDS-defining diseases than the viral load in those on ART [14,15]. However, it should be remembered that CD4 cell count and viral load responses do not precisely reflect the expected clinical outcome and are not perfect surrogates of the clinical response [9,16,17]. This is because the drugs have other effects with clinical consequences besides those reflected in viral load and CD4 cell count changes. Even so, for patients with a given CD4 cell count and viral load, the risk of AIDS disease appears to be similar, regardless of the specific antiretroviral drugs being used [18]. The relatively short length of trials designed to obtain drug approval means that, at the time of licensing, little is known about the long-term consequences of a drug. As stated above, most antiretroviral drug trials are performed by pharmaceutical companies as part of their efforts to obtain licensing approval and the designs are often not ideally suited to deriving information on using the drugs in clinical practice. Besides the short duration of follow-up, their key limitation is the lack of data on outcomes in people who change from the original randomized regimen and a description of what those new regimens are. The results are, therefore, only clearly interpretable as long as a very high proportion of participants remain on the original, allocated regimens. Clinical questions about which drugs to start with, or switch to, require longer term trials that continue following patients despite changes to the original treatment. Such changes in regimen are common in real-life practice and so, from a clinical perspective, it makes little sense to ignore what happens to patients after a specific regimen has been discontinued. The use of a given drug can affect outcomes long after it has been stopped. For example, it may select for virus resistant to drugs not yet encountered or cause toxicities that overlap with those caused by other drugs. However, interpretation of such longer term trials is not straightforward, and account must be taken of which drugs were used subsequent to the original regimen in each arm. The Writing Group generally favours entry into well-constructed trials for patients whose clinical circumstances are complex, with a number of specific instances being mentioned in these guidelines. NAM maintains a list of trials currently recruiting in the UK at http://www.aidsmap.com, and treatment units should work to ensure arrangements are in place to enable eligible patients to enter trials at centres within or indeed outside their clinical networks. In most efficacy trials, treatments are compared in terms of viral load as defined by plasma HIV RNA. Depending on the target population, the primary outcome measure may be defined to include the achievement of viral suppression below a certain limit (usually 50 HIV-1 RNA copies/mL) at a pre-specified time (e.g. 24 or 48 weeks after randomizations), time to viral rebound or time-weighted average change from baseline. To avoid selection bias, all enrolled patients must be included in an analysis comparing the treatments, and all in the group to which they were randomized, even if no longer taking the treatment they were allocated (the intent-to-treat principle). The inability to assess outcomes for some patients, leading to missing data, for example as a result of patient dropout before completion of the trial, is a potential source of bias. The frequency of and reasons for missing outcomes may be affected by many factors, including the efficacy of treatments, toxicity and the length of follow-up. Interpretation of the results of the trial is particularly problematic if a substantial number of patients drop out for reasons related to the outcome whether by design, as in many pharmaceutical industry trials where patients are withdrawn when they change their randomized treatment, or otherwise. This problem can be addressed at three levels: in the design, conduct and analysis stages of the trial. Changes in treatment during the trial must be anticipated and it is necessary to continue collecting data on all patients, even if they have switched from the original regimen, thus avoiding missing data by design and/or poor implementation. While several analytical methods have been published for handling missing outcome in clinical trials, all make assumptions that cannot be completely verified. Whichever method is used for handling missing outcomes at the analysis stage must be pre-specified in the protocol or the statistical analysis plan. When the outcome is the proportion of people with viral load below 50 copies/mL at a given time-point, the approach widely adopted is to assign an outcome of failure to achieve a value below 50 copies/mL to all patients with missing outcome (and those who have switched from the randomized treatment, regardless of whether they remain under follow-up). This is known as the missing equals failure (MEF) approach [14–21]. This approach to missing outcome is used in trials for drug licensing because it considers anyone who has to stop the drug of interest as having failed and thus prevents any tendency for drugs used by a patient after the drug of interest has failed to influence the trial results. Such an approach implicitly equates failure of a regimen as a consequence of inadequate potency and/or viral drug resistance not only with the inability to tolerate a regimen compared with other possible approaches because of pill burden, inconvenience and/or adverse effects but also with assessments being missing for other reasons, including randomly missing visits, even though the implications of these various outcomes are likely to be substantially different. This approach is often labelled conservative compared with other possible approaches because it gives a minimum proportion of patients with viral load below 50 copies/mL for any given treatment group over all possible approaches. However, the primary purpose of an endpoint is to compare treatment arms and the reasons for missing outcomes may well differ between treatments. In this context, this approach is not conservative in any general sense and its indiscriminate use without consideration of its inherent limitations involves a degree of risk of bias that could be greater than simply ignoring missing values. For these reasons, trials that are conducted for purposes of licensing a particular drug, and which treat stopping of the drug as treatment failure and ignore outcomes occurring after the drug has stopped, do not always provide the type of information that is most useful for clinical practice. In the past, trials have generally considered whether the viral load is below 50 copies/mL or not at a given time-point (e.g. 48 weeks). In recent years, the tendency has been to consider whether virological failure (or ‘loss of virological response’, usually defined as two consecutive values above 50 copies/mL) has occurred by a certain time-point, rather than whether the viral load at the time-point is below 50 copies/mL or not, as described above. In the (common) case where missing viral load values and switches in therapy are treated the same as values above 50 copies/mL, this approach uses a ‘time to loss of virological response’ (TLOVR) algorithm [20]. The two approaches will give similar but not identical results; for example, patients can fulfil the definition of loss of virological response before 48 weeks but then have a viral load value below 50 copies/mL at 48 weeks itself, without any change in regimen. Randomization in a trial ensures balance in prognosis between the treatment arms at baseline. Inability to assess outcomes for some patients can disturb this balance and create bias in the comparison between the treatment arms. In order to avoid risk of such bias, analysis by intent to treat includes outcomes for all randomized patients. So-called ‘on-treatment’ analyses consider outcomes only in those still receiving the original allocated treatment. Here, the difference between assessing the proportion with viral load below 50 copies/mL at a given time-point and assessing the proportion with viral load above 50 copies/mL by a given time-point becomes greater. In the context of an assessment of the proportion of people with viral load below 50 copies/mL at a given time-point, on-treatment analysis makes little sense because therapy has been switched in patients who experience viral load rebound during a trial, so the only patients who remain on the regimen are those with viral load below 50 copies/mL. Hence, all regimens that lead to a viral load below 50 copies/mL in at least one person should lead to a value of 100%, unless there are patients who have viral load above 50 copies/mL at the time-point but are yet to have their regimen switched. In contrast, an assessment of whether the viral load was above 50 copies/mL by a given time-point (i.e. time to virological failure or loss of virological response), which censors observation on patients once they have switched from the original randomized regimen, may be more revealing, but is still subject to potential bias. In contrast to superiority trials where the primary objective is to demonstrate that a new treatment regimen, or strategy, is more efficacious than a well-established treatment, the aim of a noninferiority trial is to show that there is no important loss of efficacy if the new treatment is used instead of the established reference. This is particularly relevant in evaluating simplification strategies where the new treatment strategy is better than the reference treatment in aspects other than efficacy, for example toxicity, tolerability or cost. A critical aspect of noninferiority trials is the judgement of what degree of possible loss of efficacy will be tolerated – the noninferiority margin (sometimes referred to as the delta). The choice of the noninferiority margin depends on what is considered to be a clinically unimportant difference in efficacy taking into account other potential advantages of the new treatment. To demonstrate noninferiority, large numbers of patients are usually required because of the need to exclude the possibility that there is even moderate loss of efficacy with the new treatment. The trial protocol must pre-specify the noninferiority margin (e.g. the proportion with viral load below 50 copies/mL at 48 weeks, in people receiving the new treatment, is not smaller than the same proportion in the reference treatment by more than 5%). As an illustration of the interpretation of the results of noninferiority trials, we shall consider the case where the primary efficacy outcome is the proportion of participants with viral load below 50 copies/mL at 48 weeks. Conclusions on the noninferiority of a new treatment are then based on the lower confidence bound, which is the lower limit of the one-sided 95% (or sometimes 97.5%) confidence interval for the difference (new – standard) between the outcome for the new treatment and the outcome for the standard treatment. Noninferiority is indicated when this lower confidence bound for the difference between the two treatments excludes loss of efficacy greater than the pre-specified noninferiority margin. So, for example, if the proportion with viral load <50 copies/mL with the standard treatment is 85% and the corresponding proportion with the new treatment is 87%, then the observed difference in proportions (new – standard) is 2%. If the lower confidence bound of this difference is −8%, this can be interpreted as meaning that (within the appropriate level of confidence) the new treatment is at most 8% inferior to the standard treatment. If (and only if) our pre-specified noninferiority margin is 8% or above then this means we would conclude that the new treatment is noninferior to the standard. If the proportions were instead 85% for the standard treatment and 79% for the new treatment, with a difference of −6% and lower confidence bound of −11%, then noninferiority of the new treatment could again be concluded if the pre-specified noninferiority margin was 11% or higher regardless of whether the observed difference of −6% was significantly different from zero; i.e. even if the proportion of participants receiving the new treatment with viral load <50 copies/mL was significantly lower than the corresponding proportion for the standard treatment. If, however, the pre-specified non-inferiority margin was less than 11% (e.g. 5%) and we obtained the same outcome data, then noninferiority would not be established even if the difference between the two treatments was not This the of a choice of a noninferiority margin. have to from to which The smaller the noninferiority the the for the new treatment but the the It should be that that the response to the new treatment is not significantly inferior to that of the standard treatment in a is not evidence for It is also important to that a very high standard of trial conduct (e.g. of entry to allocated regimens and loss to is more critical in noninferiority than in superiority Such from the protocol would to bias the difference between the two treatments and thus the of Two questions we superiority or of a new treatment from the results of a trial designed to its noninferiority to the standard What about noninferiority of the new treatment on the of the results of a trial designed to demonstrate its The to the is Conclusions of superiority (or are not on the one-sided confidence interval as for noninferiority, but on the standard 95% confidence If the proportion of patients with viral load <50 copies/mL with the standard treatment is 85% and the corresponding proportion with the new treatment is then the observed difference in proportions (new – standard) is If the 95% confidence interval for this difference is with the lower bound greater than then this can be interpreted as the superiority of the new treatment at the level to the standard treatment in a regardless of the value of the pre-specified noninferiority margin. If the proportions are instead 85% for the standard treatment and for the new treatment, with a difference of and a 95% confidence interval of to then this can be interpreted as a of of the new treatment that the noninferiority margin is or If instead the noninferiority margin is is not the highly significant lower efficacy of the new treatment, because an 8% difference has been defined a as a clinically unimportant This again the of a noninferiority margin the clinically loss of efficacy with the new treatment. in to the any about noninferiority from the results of a superiority trial would not be because the noninferiority margin cannot be with of or data from the trial. It is to compare results of drug combinations in different Such comparisons are, however, difficult to because of in entry criteria with to viral load and CD4 cell methods of analysis (e.g. intent to treat of adherence and of viral load Many of ART have been only after drug It is that any adverse as as possible so that these are A by the and in the UK for reporting adverse to the treatment of HIV The for with antiretroviral drugs in primary HIV infection is as of specific responses that would be and which are associated with long-term in untreated Reduction in associated with high and CD4 during Reduction in the risk of of have results of therapy with effects on viral load and CD4 However, in order to make a the results of a randomized are The is and results are anticipated in In the treatment in primary infection a should only be considered in those any AIDS-defining a CD4 cell count cells/μL (i.e. for or data show that of patients with HIV infection in the UK remain when have a CD4 cell count below cells/μL In data from two BHIVA have that of patients have CD4 cell counts less than cells/μL when therapy is It has been clearly that therapy with a CD4 cell count below cells/μL is associated with a substantially greater risk of disease and and this risk for a significant after treatment is the Writing Group that should be to start treatment before the CD4 cell count has to less than that adherence to ART is critical to treatment and may be on the of the for treatment, the advantages and of treatment should ideally at an for example when the CD4 count below from UK that, even in patients whose HIV infection is relatively highly antiretroviral therapy has often not been the CD4 cell count has below cells/μL (the minimum CD4 count for in the of these The reasons for this are likely to include the that patients and may to start the sometimes of to treatment As a means of with patients, Table gives an of the risk of disease over the following if HAART is or This the that the in risk is in those patients with a high risk (i.e. those who are and who have a CD4 cell count and high viral It is important to out that these data do not that may be in part by of HAART and disease It may also be that patients who are at a high risk of for example over are likely to more from treatment from the the from that there is a of risk of and disease associated with lower CD4 cell counts and no specific at which risk has that untreated HIV infection is associated with greater of and that have not been to be including those to In those individuals the who were treatment-naïve or who not been on therapy for the the risk of a new of disease or a event in the treatment was 7.0 compared with in the virological suppression However, this also means that of therapy were required to one if treatment was before the CD4 count below As a result of these factors, our is that the of therapy should be in all patients with a CD4 count of cells/μL on at least one consecutive in the of any reason for CD4 have that CD4 may have a value of the CD4 cell count, although the data are This may of antiretroviral treatment in some patients with CD4 counts cells/μL but high CD4 but also may support a to start therapy in patients with CD4 counts >350 cells/μL but with CD4 where is indicated some have indicated risk of disease in patients with CD4 As above, at CD4 counts >350 have that there might be to This is by data from the of patients not on therapy at entry to the of the about of therapy have been because of the of less and better tolerated antiretroviral and options after virological For the of patients, the risk of therapy the CD4 count is cells/μL is likely to be but in a at particularly high risk of clinical that may be by this is not the For all these reasons, in a number of patients, treatment may be or considered before the C

CLT, Cadaveric liver transplantation; LDLT, live donor liver transplantation; PEI, Percutanoeus ethanol injection; RF, radiofrequency; TACE, Transarterial chemoembolization; PS, Performance Status. These recommendations provide a data-supported approach to the diagnosis, staging and treatment of patients diagnosed with hepatocellular carcinoma (HCC). They are based on the following: (a) formal review and analysis of the recently-published world literature on the topic (Medline search through early 2005); (b) American College of Physicians Manual for Assessing Health Practices and Designing Practice Guidelines.1 (c) guideline policies, including the AASLD Policy on the Development and Use of Practice Guidelines and the AGA Policy Statement on Guidelines2; (d) the experience of the authors in the specified topic. We have also reviewed the guidelines prepared at the time of the Monothematic Conference of the European Association for the Study of the Liver (EASL)3 and the practice of authors experienced in the field. Intended for use by physicians, these recommendations suggest preferred approaches to the diagnostic, therapeutic, and preventive aspects of care. They are intended to be flexible, in contrast to standards of care, which are inflexible policies to be followed in every case. Specific recommendations are based on relevant published information. In an attempt to characterize the quality of evidence supporting recommendations, the Practice Guidelines Committee of the AASLD requires a category to be assigned and reported with each recommendation (Table 1). These recommendations are fully endorsed by the American Association for the Study of Liver Diseases. Over the last 5 to 8 years evidence has been accumulating in different countries that the incidence of hepatocellular carcinoma (HCC) is rising.4-9 Traditionally, the care of patients with HCC has been undertaken by hepatobiliary surgeons, interventional radiologists, and oncologists. Hepatologists in North America are not trained to perform the procedures required to treat HCC, such as alcohol injection, radiofrequency ablation, or hepatic artery catheterization, although hepatologists in Japan and elsewhere may perform many of these procedures. As a result, the role of the hepatologist traditionally has been limited to making the diagnosis and providing care of the underlying liver disease. However, more recently, the role of the hepatologist has changed. First, in many centers the development of multidisciplinary clinics has emphasized the role of the hepatologist in assessing the patient's liver disease status, and carefully managing the liver disease before and during treatment. The hepatologist has also become more actively involved in deciding what form of therapy is most appropriate and whether the patient's liver function would allow that form of therapy to be given. In addition, arising out of caring for patients with end stage liver disease, hepatologists also institute surveillance for HCC and manage the investigation of abnormal results. Finally, hepatologists are involved in the decision whether or not to offer liver transplantation to patients with HCC. There have been many reviews of various aspects of the care of patients with HCC, but only one clinical practice guideline has been published in the Western literature. The European Association for Study of the Liver (EASL) sponsored a single topic conference on HCC in 2000. The proceedings of this conference were published in 2001.3 This document largely reflected practices in Europe, and possibly North America, whereas practices in Japan are somewhat different. Definitions of the terms used in this section are given in Table 2. Surveillance for HCC involves more than simply applying a screening test or tests. Surveillance should be offered in the setting of a program or a process in which screening tests and recall procedures have been standardized and in which quality control procedures are in place. The process of surveillance also involves deciding what level of risk of HCC is high enough to trigger surveillance, what screening tests to apply and how frequently (surveillance interval), and how abnormal results should be dealt with (diagnosis and/or recall). Surveillance for HCC has become widely applied despite, until recently, the absence of evidence of benefit. There is a single randomized controlled trial of surveillance versus no surveillance that has shown a survival benefit to a strategy of 6-monthly surveillance with alphafetoprotein (AFP) and ultrasound.10 This study, which was performed in China, recruited 18,816 patients who had markers of current or prior hepatitis B infection. Adherence to surveillance was suboptimal (less than 60%) but in the subjects in the surveillance arm the HCC related mortality was reduced by 37%. These results probably represent the minimum benefit that can be expected from surveillance, because of poor compliance. In contrast, an earlier study, also conducted in China failed to show benefit, largely because patients who were diagnosed with HCC did not undergo appropriate treatment.11 Ideally, these results should be validated in other geographical areas and therefore, additional randomized controlled trials (RCT) assessing the benefits of surveillance are still considered necessary. Such trials would be difficult to undertake, but are essential to unequivocally determine the benefit of surveillance in reducing HCC mortality. The objective of HCC surveillance must be to decrease mortality from the disease. Fewer people should die from HCC, or if this is not possible, surveillance should at a minimum provide a meaningful improvement in survival duration. Other endpoints, such as stage migration (detecting earlier disease) and 5-year mortality rates are not appropriate surrogate endpoints. This has clearly been shown by analysis of the Surveillance, Epidemiology and End Results (SEER) Program of the National Cancer Institute (NCI), which demonstrated that these endpoints did not correlate with a reduction in disease-specific mortality.12 There are several sources of bias to be considered in assessing reports of surveillance studies, such as lead-time bias and length bias. Only a RCT can eliminate these biases completely. Several studies have shown that surveillance does detect earlier disease (stage migration).13-16 However, as discussed above, this does not correlate well with reduction in disease-specific mortality. Uncontrolled studies, all subject to lead-time bias, have suggested that survival is improved after surveillance.13, 16 Surveillance for HCC is widely practiced and can generally be recommended for certain at-risk groups. HCC detected after the onset of symptoms has a dismal prognosis (0%-10% 5-year survival).17 In contrast, small HCCs can be cured with an appreciable frequency.17-21 Five-year disease-free survival exceeding 50% has been reported for both resection and liver transplantation.17, 22-30 Patients surviving free of disease for this duration must be considered cured. For these patients it is highly likely that surveillance did indeed decrease mortality. Since major advances in our ability to treat HCC are less likely to come from treating late stage disease it is therefore important to find early stage disease. The decision to enter a patient into a surveillance program is determined by the level of risk for HCC. This, in turn, is related to the incidence of HCC, and it is incidence that most people use to assess risk. However, there are no experimental data to indicate what level of risk or what incidence of HCC should trigger surveillance. Instead, decision analysis has been used to provide some guidelines as to the incidence of HCC at which surveillance may become effective. An intervention is considered effective if it provides an increase in longevity of about 100 days, i.e., about 3 months.31 Although the levels were set years ago, and may not be appropriate today, interventions that can be achieved at a cost of less than about $50,000/year of life gained are considered cost-effective.32 There are now several published decision analysis/cost-efficacy models for HCC surveillance. The models differ in the nature of the theoretical population being analyzed, and in the intervention being applied. Nonetheless, these models have several results in common. They all find that surveillance is cost-effective, although in some cases only marginally so, and most find that the efficacy of surveillance is highly dependent on the incidence of HCC. For example, Sarasin et al.33 studied a theoretical cohort of patients with Child–Pugh A cirrhosis and found that if the incidence of HCC was 1.5%/year surveillance resulted in an increase in longevity of about 3 months. However, if the incidence of HCC was 6% the increase in survival was about 9 months. This study did not include transplantation as a treatment option. Arguedas et al.,34 using a similar analysis which did include liver transplantation in a population of hepatitis C patients with cirrhosis and normal liver function, found that surveillance with either CT scanning alone or CT scanning plus ultrasound became cost-effective when the incidence of HCC was more than 1.4%. However, this study has to be interpreted cautiously, because the performance characteristics of CT scanning were derived from diagnostic studies, not surveillance studies (see Surveillance Tests). Lin et al.35 found that surveillance with AFP and ultrasound was cost-effective regardless of HCC incidence. Thus, for patients with cirrhosis of varying etiologies, surveillance should be offered when the risk of HCC is 1.5%/year or greater. Table 3 describes the groups of patients in which these limits are exceeded. These groups of patients are also discussed in more detail below. The above cost-efficacy analyses, which were restricted to cirrhotic populations, cannot be applied to hepatitis B carriers without cirrhosis. These patients, particularly in Asia and Africa, are also at risk for HCC. A cost-efficacy analysis of surveillance of hepatitis B carriers using ultrasound and AFP levels suggested that surveillance became cost-effective once the incidence of HCC exceeded 0.2%/year (Collier J and Sherman M, unpublished observations). The subgroups of hepatitis B carriers in which the incidence of HCC exceeds 0.2%/year are given in Table 3. These groups are discussed in more detail below. Beasley et al., in a prospective controlled study showed that the annual incidence of HCC in hepatitis B carriers was 0.5%.36-38 The annual incidence increased with age, so that at age 70 the incidence was 1%. The incidence in patients with known cirrhosis was 2.5%/year. The relative risk of HCC was about 100, i.e., hepatitis B carriers were 100 times more likely to develop HCC than the uninfected. Sakuma et al.39 found the incidence of HCC in male Japanese railway workers was 0.4%/year. Both these populations were male and Asian, with the hepatitis B infection likely acquired at birth or in early childhood. Uncontrolled prospective cohort studies in North America, where the epidemiology of hepatitis B is different, i.e., hepatitis is acquired later in life, have indicated that the incidence of HCC in HBV carriers varies widely.40-42 Villeneuve et al.40 found no tumors in a cohort infected with HBV and followed for 16 years. McMahon et al.41 reported an incidence of HCC of 0.26%/year in a study of HBV-infected individuals in Alaska. Sherman et al.42 described an incidence of 0.46%/year in their cohort. In Europe HCC in hepatitis B carriers occurs mainly in patients with established cirrhosis.43, 44 Non- Asian chronic carriers who are anti-HBe-positive with long-term inactive viral replication and who do not have cirrhosis seem to have little risk of developing HCC.45-48 Whether surveillance is worthwhile in this population is not clear. This is not true for Asian hepatitis B carriers without cirrhosis, who remain at risk for HCC regardless of replication status.45, 49-51 Similarly, the risk of HCC persists in long-term HBV carriers from Asia who lose HBsAg, and these patients should continue to undergo surveillance.52 In Caucasian hepatitis B carriers who lose surface antigen the risk of HCC seems to decline dramatically.53, 54 The annual incidence of HCC in male hepatitis B carriers from South East Asia only starts to exceed 0.2% at about age 4038 irrespective of presence of cirrhosis or disease activity. In contrast, in Caucasians the risk is related to inflammatory activity and the presence of cirrhosis. Therefore Asian men should undergo surveillance from age 40 onwards. HCC will occur in younger patients, but the efficacy of providing surveillance to all carriers younger than age 40 is likely to be low. The incidence of HCC in women is lower than in men, although age-specific incidence rates are hard to come by. Nonetheless, it seems appropriate to start surveillance at about age 50 in Asian women. All hepatitis B carriers with cirrhosis, regardless of age should be screened for HCC. In the presence of a history of a first degree relative with HCC surveillance should start at a younger age than 40,55 although what that age should be is hard to define. Africans with hepatitis B seem to get HCC at a younger age.56, 57 Expert opinion suggests that surveillance in these populations should also start at a younger age. Whether this is true in Blacks born elsewhere is uncertain. In Caucasian hepatitis B carriers with no cirrhosis and with inactive hepatitis, as determined by a long term normal ALT and low HBV DNA concentration44, 46, 47, 58 the incidence of HCC is probably too low to make surveillance worthwhile. However, there are additional risk factors that have to be taken into account, including older age, persistence of viral replication and co-infection with hepatitis C or HIV, or the presence of other liver diseases. Nevertheless, even in the absence of cirrhosis, adult Caucasian patients with active disease are likely at risk for HCC, and should be screened. The risk of HCC in patients with chronic hepatitis C is highest and has been best studied in patients who have established cirrhosis,59-62 in whom the incidence of HCC is between 2%-8% per year. It should be noted that these data come from clinic-based studies. There is a single prospective population-based study of the risk of HCC in patients with hepatitis C.63 In this study of 12,008 men being anti-HCV-positive conferred a 20-fold increased risk of HCC compared to anti-HCV-negative subjects. The presence or absence of cirrhosis was not evaluated. Hepatitis C infected individuals who do not have cirrhosis have a much lower risk of developing HCC.64 However, the transition from bridging fibrosis to cirrhosis cannot be determined clinically so that the clinician cannot easily determine when these patients start to develop a significant increase in risk of HCC. For this reason the EASL conference3 suggested that surveillance may be offered to patients with hepatitis C and cirrhosis or with bridging fibrosis or transition to cirrhosis. The cost-efficacy of this recommendation has not been evaluated. Based on current knowledge, all patients with hepatitis C and cirrhosis should undergo surveillance. Whether patients with bridging fibrosis should also undergo surveillance remains controversial. There have been several attempts to develop non-invasive markers to predict the stage of fibrosis65-67 and if properly validated, these could be used to determine when to initiate surveillance. Similarly, several other markers may predict a significant risk of HCC. One such marker may be the platelet count. It has been suggested that the incidence of HCC in hepatitis C cirrhosis only increases substantially once the platelet count is less than 100×109/L,62, 68, 69 regardless of liver function. This needs to be validated. Others have attempted to develop predictive indices based on panels of commonly performed serological tests such as alpha 2-macroglobulin, apolipoprotein A1, haptoglobin, bilirubin and gamma-glutamyl-transpeptidase and the AST/ALT ratio.67, 70 However, these indices have still to be validated before entering general use and cannot be recommended at present. Patients who are co-infected with HIV and either hepatitis B or hepatitis C may have more rapidly progressive liver disease71 and when they reach cirrhosis they are also at increased risk of HCC.72 The MORTAVIC study indicated that HCC was responsible for 25% of all liver deaths in the post-HAART era.73, 74 The criteria for entering co-infected patients into programs for HCC screening are the same as for mono-infected patients, i.e., criteria based on the stage and grade of liver disease as described above. The incidence of HCC in cirrhosis caused by diseases other than viral hepatitis is, with some exceptions, not accurately known. Most of the studies of the incidence of HCC in alcoholic cirrhosis date from before the identification of the hepatitis C virus. Given that hepatitis C is relatively frequent in alcoholics75-77 most of the reported HCC incidence rates in earlier studies must be over-estimates. That alcoholic cirrhosis is a risk factor for HCC is clear. In one study alcoholic liver disease accounted for 32% of all HCCs.78 In an Austrian cohort with HCC alcoholic liver disease was the risk factor in 35% of subjects.79 In the United States the approximate hospitalization rate for HCC related to alcoholic cirrhosis is 8-9/100,000/year compared to about 7/100,000/year for hepatitis C.80 This study did not determine the incidence of HCC in alcoholic liver disease, but it does confirm that alcoholic cirrhosis is a significant risk factor for HCC, probably sufficient to warrant surveillance for HCC. With the recognition of steatohepatitis as a cause of cirrhosis, has come the suspicion that this too is a risk factor for HCC. No study to date has followed a sufficiently large group of such patients for long enough to describe an incidence rate for HCC. In one cohort study of patients with HCC81 diabetes was found in 20% as the only risk factor for HCC. Whether or not these patients were cirrhotic was not noted. Non-alcoholic fatty liver disease (NAFLD) has been described in cohorts of patients with HCC.82, 83 Since the incidence of HCC in cirrhosis due to NAFLD is unknown it is not possible to assess whether surveillance might be effective or cost-efficient. No recommendations can be made whether this group should be screened for HCC or not. This does not preclude the possibility that surveillance is beneficial in this group, and future data may change this recommendation. Patients with genetic hemochromatosis (GH) who have established cirrhosis have an increased risk of HCC.84-86 The relative risk of HCC is about 20. The standardized incidence ratio for HCC in cirrhotic GH is 92.9 (95% confidence interval [CI] 25-237.9). The incidence of HCC in cirrhosis due to GH is sufficiently high (about 3%-4%/year) that these patients should be included in surveillance programs. The incidence of HCC in stage 4 primary biliary cirrhosis is about the same as in cirrhosis due to hepatitis C.87 For cirrhosis due to alpha 1-antitrypsin (AAT) or hepatitis there are data from cohort studies to accurately assess HCC incidence. There is as no evidence that treatment of chronic hepatitis B the incidence of HCC. in Europe suggested that therapy for chronic hepatitis B improved survival and reduced the incidence of A study from also indicated that i.e., the development of was with a reduced incidence of However, in these studies the rate was and the were relatively In contrast, a but controlled study from that included a cohort followed for found that the incidence of HCC was not in the A single RCT suggests that treatment of chronic hepatitis B carriers with cirrhosis does the incidence of but whether the risk reduction is sufficient that surveillance is not clear. a patient is a for surveillance before the of it seems to continue to offer surveillance even after or of inflammatory activity. There are a of studies the of treatment of chronic hepatitis C on the incidence of HCC. A single RCT in Japan suggested that the incidence of HCC was reduced in both and to These results could not be in a RCT from The results of these other studies were in a which that the benefit is mainly in who were i.e., had a and even the was A of studies in Japan compared the incidence of HCC in patients with that in These have suggested that there is a reduced incidence of HCC in However, no data that treating or hepatitis C the risk for HCC. it seems that patients with hepatitis C and cirrhosis who have achieved viral on therapy at for continue to undergo surveillance. that patients with or chronic hepatitis B or C may show of fibrosis sufficient to suggest of cirrhosis. The risk of HCC in these patients probably does not decrease with the improvement in There are many about the of HCC in these patients, but one factor seems to be that of and are necessary. The required to initiate the probably occur many years before the disease and so the of HCC remains even if fibrosis fibrosis is not a reason to surveillance. There are a of factors with an increased risk of HCC that are in patients at risk for developing HCC. These include an AFP presence of small and large on to and increased for antigen or of the Although such patients are at more risk of developing HCC they will likely be in surveillance programs because of other risk factors such as cirrhosis or chronic hepatitis The increased does not a change in surveillance Patients at high risk for developing HCC should be into surveillance programs The at-risk groups are in There are several for screening patients on the liver Patients should be screened for HCC to small tumors that might and to patients who develop that exceeds the guidelines for In addition, in the United the current criteria the development of HCC provides liver Thus, it would seem to be in a patient's to have a small HCC diagnosed on the liver One cost-efficacy analysis has suggested that the increase in longevity the cohort of patients is because although there may be an increase in longevity in who develop HCC, it is by the of longevity in other patients on the are so that the patient with HCC can have In contrast, identification of HCC that exceeds and of such patients, is beneficial to other patients on the analysis suggested that there were benefits to treating patients with HCC on the with either resection or The benefit in on the length of the The the the the benefit of In the United States patients to be for liver transplantation with an AFP without of HCC, even in the absence of a on It is important to that AFP is being used for diagnosis, not surveillance. Nonetheless, the performance characteristics of even as a diagnostic test are particularly in the absence of a on (see 2. Patients on the should be screened for HCC because in the the development of HCC increased for and because to for HCC that patients may develop HCC and criteria without the being that is used to determine the presence or absence of a disease must be validated using a of that determine how well the test in the disease no test is The are the and which are For single test and the underlying disease, as the diagnostic of test is related to the of the underlying disease in the population being This is by the and predictive i.e., the rates at which or results are An of the of a test can also be free of the of disease incidence by using the This is a of the and the performance characteristics of a test the of the test results the for diagnosis can be from the a of the of the test results. An important additional is that the history of liver is not the same as for clinical In rates of may be different than rates in clinically may not to clinically in all it cannot be that all found on surveillance will develop into Similarly, the performance characteristics of a test used to disease as a screening are not the same as when the test is used for Therefore one cannot the performance characteristics of a test used in diagnosis CT and the and to the surveillance tests into serological and the serological tests the performance characteristics of AFP have been best analysis of AFP used as a diagnostic test suggests that a of about provides the between and However, at this level the is only i.e., AFP surveillance would of HCC if a of is used as the trigger for This is for general a is used a of HCCs will be the AFP is the to reducing the that more HCCs would be but at the cost of a progressive increase in the This analysis was performed in a control study where the of HCC was set at this the predictive of an AFP of was However, if the HCC rates were more in most liver i.e., about the predictive of an AFP of is only and even at a of the is only In cohorts surveillance the incidence of HCC may be even lower than on the criteria for into surveillance. For example, in hepatitis B carriers infected at birth the incidence of HCC is less than 1%. AFP is an screening AFP still has a role in the diagnosis of HCC, in cirrhotic patients with a in the liver an AFP than has a high predictive for a AFP has been clearly shown to be a risk factor for Thus, the AFP can be used to patients at but to have limited as a screening serological test used to HCC is the also known as by Most reports on the use of have the use of this test in a diagnostic than for surveillance. Although there are reports of use in a surveillance these do not provide sufficient for use of this There are also reports that is a marker for by this would also suggest that is not a screening A screening test should be to early

Potential conflict of interest: Listed at the end of the article for all authors. These recommendations have been approved by the American Association for the Study of Liver Diseases and the Infectious Diseases Society of America. Potential conflict of interest: Listed at the end of the article for all authors. All AASLD Practice Guidelines are updated annually. If you are viewing a Practice Guideline that is more than 12 months old, please visit www.aasld.org for an update in the material. Preamble The pace of hepatitis C virus (HCV) drug development in recent years has accelerated dramatically. For patients to benefit from these impressive advances, practitioners need access to the most up‐to‐date data and to advice from experienced experts. Such information and advice can be difficult to access readily given the diverse sources from which information is available and the sometimes lengthy time needed for publication of original articles and scholarly perspectives. Traditional practice guidelines for more established areas of medicine and care often take years to develop and bring to publication. In the new era in hepatitis C treatment, such a process would not be nimble or timely enough to address the needs of patients with HCV infection, practitioners caring for these patients, or payers approving therapies for use. A living document made available in a web‐based system, such as that used by the US Department of Health and Human Services for human immunodeficiency virus (HIV) treatment recommendations (http://aidsinfo.nih.gov/guidelines), was selected as the best model to provide timely recommendations for hepatitis C management. In 2013, the two major membership societies supporting liver and infectious disease specialists (American Association for the Study of Liver Diseases [AASLD] and Infectious Diseases Society of America [IDSA]) joined forces to develop guidance for the management of hepatitis C in this rapidly moving field. The International Antiviral Society‐USA, which has experience in developing treatment guidelines in HIV disease, was invited to join the effort as a collaborating partner responsible for managing the panel and the guidance development process. The goal of the hepatitis C guidance is to provide up‐to‐date recommendations for HCV care practitioners on the optimal screening, management, and treatment for adults with HCV infection in the United States, using a rigorous review process to evaluate the best available evidence. This review provides a condensed summary of recommendations from the guidance. The complete guidance, which is updated regularly, is available at www.hcvguidelines.org. Process This was conceived to be a living document that would reside online and undergo real‐time revisions as the field evolved. To lead the process, two cochairs selected by the governing boards of each founding society were joined by a fifth cochair representing the International Antiviral Society‐USA. These cochairs selected 10 panel members from each society. The panel members were chosen to represent expertise in the diagnosis, management, treatment, research, and patient care from the fields of hepatology and infectious diseases. At least 51% of the panelists could have no substantive industry support other than research advisory boards, data safety monitoring boards, or research funding that went to the member's employer. The panel first convened in person in October 2013. 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Arboviruses such as dengue (DENV), Zika (ZIKV), chikungunya virus (CHIKV), and Crimean-Congo hemorrhagic fever (CCHFV) have been extensively studied in cell culture and animal models, yet how these findings translate to early infection events in human skin remains largely uncertain. Standard monolayers lack the stratified architecture and resident immune cells of the epidermis and dermis, while rodent skin differs markedly in structure, immunity, and mosquito interactions. Ex vivo human skin explants bridge this translational gap by preserving the native cutaneous microenvironment, including keratinocytes, fibroblasts, Langerhans cells, dermal dendritic cells, and extracellular matrix. Thereby, they enable infection under conditions that approximate natural mosquito bite transmission, including the deposition of virus and saliva during mosquito probing and the accompanying immunomodulatory effects. This review synthesizes insights from human skin explant models and contrasts them with monolayer systems, showing how intact skin architecture reshapes early viral behavior and innate immune activation. It further highlights innovations - such as fluorescent saliva reporter mosquitoes and engineered vascular skin platforms - that enable tracking of arbovirus delivery and host responses at the vector-skin interface. These platforms hold promise not only for defining early determinants of human susceptibility, especially in the light of the recently identified arbovirus receptors, but also for testing topical or locally acting countermeasures at the true portal of viral entry. Major gaps remain, including the absence of blood circulation in currently available human skin explants, underscoring the need to extend skin explant approaches across the broader landscape of vector-borne pathogens.

Vaccine adjuvants play a critical role in enhancing the magnitude and quality of immune responses; however, limitations in the efficacy of current vaccines against certain infectious diseases, together with the ongoing emergence of new pathogens, underscore the need for the continued development of novel vaccine adjuvants. Mucosal-associated invariant T (MAIT) cells are innate-like T lymphocytes that respond rapidly during the early phase of microbial infection to amplify immune responses and bridge innate and adaptive immunity. Molecules capable of activating MAIT cells therefore have the potential to act as efficacious vaccine adjuvants. This review discusses emerging evidence supporting the potential of MAIT cell activators as vaccine adjuvants. Recent advances in the discovery and development of MAIT cell-activating ligands are summarized, highlighting natural ligands derived from microbial riboflavin metabolism, most notably 5-(2-oxopropylideneamino)-6-D-ribitylaminouracil (5-OP-RU). Several recent studies have demonstrated 5-OP-RU to be an effective adjuvant in vaccines against viral infections, markedly expanding interest in MAIT cell-targeted immunomodulation. Furthermore, ongoing efforts to overcome the intrinsic chemical instability of 5-OP-RU through rational ligand design and related strategies are described. MAIT cell activators are poised to attract increasing attention as a versatile platform for the design of next-generation vaccine adjuvants against infectious diseases.

The development of effective mucosal vaccines has been limited by the limited availability of mucosal adjuvant approaches with established clinical track records and an incomplete understanding of how systemic and mucosal immunity are coordinated. Recent studies indicate that the priming phase of vaccination plays a decisive role in programming the quality, durability, and anatomical distribution of subsequent immune responses. This review discusses emerging evidence that co-adjuvant-based priming strategies can establish long-lasting immune programs that enable adjuvant-free mucosal boosting. Focusing on the combination of CpG DNA and curdlan as a prototypical example, this review highlights how coordinated activation of innate immune receptors during priming imprints dendritic cells, B cells, and T cells to support robust mucosal IgA and tissue-resident immunity. This review further discusses translational advances demonstrating that this immune programming paradigm can be maintained using translationally oriented formulations designed with clinical development in mind and validated in non-human primates. Independent studies using mRNA and protein-based vaccines support the general principle that the quality of priming, rather than the boosting modality, determines successful mucosal immunity. Together, these findings redefine vaccine adjuvants as tools for immune programming and provide a conceptual framework for next-generation vaccine design.

Plant viruses rely on insect vectors to complete their transmission cycles, exploiting a diverse array of vector proteins to enable entry, intracellular movement, replication, and exit. This review synthesizes recent advances in our understanding of plant virus-vector protein interactions across noncirculative (NC) and circulative transmission modes, including vertical transmission. Key viral strategies include binding to surface proteins (e.g. Stylin-01, KRT), traversing epithelial barriers via receptor-mediated endocytosis (e.g. APN, ST6), trafficking through intracellular compartments (e.g. SNARE complexes, flotillin-2), and release through salivary exosomes. Some viruses hijack autophagy and apoptosis machinery to avoid degradation and ensure persistence. Others exploit reproductive proteins such as vitellogenin and sperm-specific serpin proteins - or even symbiont-derived membrane proteins - to achieve vertical transmission. In response, vectors activate immune pathways including RNA interference (RNAi), melanization, and mitogen-activated protein kinase signaling, although these defenses are frequently subverted by viral proteins. Mapping these molecular interactions highlights promising targets for intervention, including vector-targeted antibodies, RNAi-enabled symbionts, and receptor-blocking molecules. Together, these insights offer a path toward molecularly precise, ecologically sustainable strategies for disrupting plant virus transmission at the vector level.

Viral infection-related hospitalization and mortality rates are highest in human newborns and infants compared to older children and adults, suggesting age-specific vulnerability and a non-redundant role for the maternal immune system. However, there is immense interindividual variability of clinical outcomes following early-life exposure to nearly any given virus that cannot be fully explained by variation in maternal immune protection. Inborn errors of immunity underlying defective control of viral replication or insufficient immune regulation following a viral trigger are increasingly recognized as the molecular etiology of severe viral disease in children and adults. In parallel, auto-antibodies (auto-Abs) neutralizing type I interferons&#xa0;(IFNs) are emerging as universal determinants of viral disease. The role of inborn errors of antiviral immunity in the fetus, the newborn, and the infant is starting to emerge or can be inferred from the study of viral disease in older individuals. The investigation of the molecular mechanisms underlying early-life viral disease in individual patients is crucial to the development of effective prevention and treatment strategies. Novel studies addressing the role of inborn errors of antiviral immunity or auto-Abs neutralizing type I IFNs&#xa0;in early-life viral infections should take into account the specific aspects of the neonatal immune system and its complex interactions with the maternal immune system.

Intracranial calcifications (ICCs) are a characteristic neuropathological feature of several congenital viral infections, including Zika virus (ZIKV), cytomegalovirus (CMV), and lymphocytic choriomeningitis virus (LCMV). These lesions are linked to severe neurodevelopmental outcomes, such as microcephaly, epilepsy, and cognitive deficits, yet the mechanisms underlying their formation and resolution remain unclear. ICCs are thought to arise from an imbalance in osteogenic and osteolytic signaling in the developing brain. Recent work implicates pericytes as key targets of ZIKV, capable of osteogenic reprogramming and direct mineral deposition. However, the pathways leading to calcification in CMV and LCMV infections are less well understood. Microglia, the brain's resident immune cells, have emerged as potential regulators of calcification. While microglia can limit mineral deposition in noninfectious models of neurodegeneration and injury, their role in the context of congenital viral infection remains speculative. Whether they act to contain calcification, participate in its resolution, or contribute to pathogenesis via neuroinflammatory signaling is still unknown. This short review summarizes current knowledge of ICC pathogenesis during congenital ZIKV, CMV, and LCMV infections, with a focus on emerging potential cellular mediators, such as pericytes and microglia. We discuss known mechanisms, gaps in knowledge, and opportunities to build more representative animal models to elucidate how different viral infections orchestrate calcification in the fetal brain. Clarifying these pathways may inform future therapeutic approaches to mitigate virus-induced neurodevelopmental disorders.

Inborn errors of immunity can underlie susceptibility to severe viral infection in humans. and the majority relate to defective induction of or response to antiviral type I interferon (IFN). However there is increasing awareness of defects in other cellular processes, that can predispose to severe infectious disease. Recently, defects in autophagy-related genes or -processes have been demonstrated to predispose to life-threatening viral diseases, including defects in autophagy-related genes in patients with herpes simplex virus and varicella zoster virus infections in the central nervous system, as well as impairment of noncanonical antiviral immunity in critical COVID-19. However, the molecular mechanisms and complex intersections between autophagy, metabolism, cell death, and inflammation, and how defects in autophagy-related proteins may interfere with these cellular processes, are only now starting to emerge. This review presents the current knowledge on inborn errors of autophagy discovered in patients with severe viral infection and discusses some of the remaining knowledge gaps in our understanding of how autophagy processes act against viruses, how immunopathology and lack of viral control ensues when they fail, and how these insights may be translated into clinical medicine.

Host defense against intracellular pathogens, including viruses and mycobacteria, requires not only antibody production but also T cell-mediated cellular immunity, which is often overlooked in current vaccine strategies. C-type lectin receptors (CLRs) are one of the innate immune receptors that can promote adaptive immunity through the induction of co-stimulatory molecules or soluble factors in antigen-presenting cells. This review focuses on the potential of CLR ligands, specifically those for macrophage-inducible C-type lectin (Mincle), as next-generation vaccine adjuvants. Mincle recognizes glycolipids such as trehalose dimycolate (TDM) from mycobacteria and induces Th1 and Th17 responses, crucial mechanisms for countering intracellular pathogens. We discuss the structural basis of the ligand-recognition modes of Mincle, which involves both sugar-binding pockets and hydrophobic grooves to accommodate acyl chains. Additionally, we discuss efforts to develop synthesizable and highly active ligands such as trehalose dibehenate (TDB) and lipidated brartemicin (C18Brar). We further highlight novel strategies to enhance immunostimulatory efficacy, including the concept of dual-ligand adjuvants (e.g. C18Brar-muramyl dipeptide conjugate) and the use of nanoparticle/liposome delivery systems (e.g. CAF formulations). Collectively, these advancements highlight the potential of Mincle ligands as candidates for effective adjuvants. For clinical application, species-specific differences in adjuvant effectiveness between humans and experimental animals must be addressed, and highly functionalized Mincle ligands must be developed. Future research should establish Mincle-targeting ligands as indispensable tools for the development of next-generation vaccines.

Arthritogenic alphaviruses, including chikungunya (CHIKV), Ross River, and Mayaro viruses, are emerging global viruses responsible for causing arthralgia and chronic arthritis. Following mosquito-borne transmission, they quickly initiate infection in the skin, including in resident immune cells, and disseminate systemically into musculoskeletal tissues. The innate immune system responds rapidly through the activation of interferons, the production of inflammatory cytokines, and the recruitment of monocytes, macrophages, neutrophils, and dendritic cells, while the adaptive immune response, particularly virus-specific T and B cells, is critical for viral clearance. However, excessive immune activation can lead to both acute and chronic musculoskeletal pain through cytokine storm, tissue damage, and supporting immunopathology. Additionally, viral persistence and immune evasion may contribute to the development of chronic synovitis and cartilage degradation, leading to persistent joint pain. Despite recent advances, antiviral treatments remain unavailable, and to date, there is only one vaccine licensed (VIMKUNYA&#x2122; in 2025, against CHIKV), underscoring the urgent need for further research. This review explores the complex interplay between host immune responses and viral factors that lead from acute infection to chronic inflammation. Furthermore, it highlights key gaps in understanding viral persistence&#xa0;and immune evasion, and how to predict chronic diseases to improve therapeutic and preventive strategies against arthritogenic alphaviruses.

While injectable vaccines can prevent respiratory pathogens from causing severe disease, their ability to elicit protective local immunity in the respiratory mucosa is more limited. For viral pathogens, infection outcome is often determined at the site of entry, where innate immune sensing within the airway mucosa precedes and conditions adaptive immune responses. At these surfaces, epithelial cells and antigen-presenting cells express a wide repertoire of pattern recognition receptors (PRRs), positioning innate immune activation as a central determinant of vaccine efficacy and durability of mucosal immunity. Recent advances in mucosal immunology facilitate the progression of mucosal vaccine development from empirical formulation toward mechanism-informed targeting of innate immune pathways. This review highlights emerging evidence supporting targeted engagement of cytosolic and endosomal PRRs to enhance intranasal vaccine efficacy. We focus on the cyclic GMP-AMP synthase-stimulator of interferon genes (STING) pathway, highlighting how spatially and temporally constrained STING activation can drive interferon-mediated antiviral immunity, enhance antigen presentation and promote tissue-resident T cells. We also discuss how complementary targeting of endosomal PRRs, including TLR3 and TLR9, further reinforces antiviral programming and adaptive immunity at mucosal sites.

Type I interferons (IFN-Is) are critical antiviral cytokines that restrict viral replication and limit viral disease. A remarkable recent discovery is that human autoantibodies (autoAbs) neutralizing the activities of IFN-Is phenocopy inborn errors of immunity and markedly exacerbate susceptibility to life-threatening infections. Development of these pathogenic autoAbs in humans is strongly linked to genetic and nongenetic factors affecting thymic function, and they are estimated to be present in >100 million people worldwide with a prevalence that increases with age. Here, we review major advances from the last few years that have improved our mechanistic understanding of human IFN-I autoAb development and function, as well as their association with a significant proportion of different severe viral diseases. In particular, we highlight how neutralizing IFN-I autoAbs can persist in individuals for decades, compromising IFN-I-mediated defenses, and underlying subsequent critical infections with diverse pathogens, including SARS-CoV-2, West Nile virus, tick-borne encephalitis virus, seasonal influenza viruses, herpesviruses, and rare zoonoses caused by MERS-CoV, flaviviruses, and avian H5N1 influenza A virus. Furthermore, we discuss how neutralizing IFN-I autoAbs facilitate severe adverse events with live-attenuated viral vaccines, such as the yellow fever or chikungunya virus vaccines, and suggest how implementation of IFN-I autoAb diagnostics in at-risk populations may be clinically beneficial with current prophylactic or therapeutic options. Finally, in the context of new experimental insights into how autoAbs block the ability of IFN-Is to engage with the IFNAR1/IFNAR2 receptors, we detail future opportunities to design advanced novel therapeutic strategies that might specifically mitigate IFN-I autoAb pathogenic effects.

The coronavirus disease&#xa0;2019 (COVID-19) pandemic emphasized the need to study coronaviruses more thoroughly. Next to severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), humans can be infected by SARS-CoV, Middle East respiratory syndrome coronavirus (MERS-CoV), and various seasonal coronaviruses. It is likely that all human coronaviruses have a zoonotic origin and circulated in animal reservoirs before crossing the species barrier into humans. Historically, these viruses have been investigated in vitro and in vivo, mainly utilizing immortalized cell lines and animal models, respectively. Recently, more advanced physiological model systems have been developed to study coronavirus&#xa0;host interactions, with human organoids serving as innovative in vitro tissue culture system that closely mimics human physiology. Organoids provide a promising platform for investigating coronavirus infections, exploring viral tropism, studying host immune responses, and evaluating potential therapeutic interventions. This review explores the origins and use of airway organoids in studying coronaviruses. Additionally, it outlines prospects for leveraging airway organoids for examination of both innate and adaptive immune responses, evaluation of antiviral drugs, and creating intricate co-culture models for enhanced insight into coronavirus infections of the respiratory tract.

Vaccine adjuvants play a central role in shaping the magnitude, quality, and durability of vaccine-induced immune responses, yet their rational design and selection remain major challenges. Although the adjuvant repertoire has expanded substantially over the past two decades, this growth has not yielded broadly predictive frameworks capable of matching adjuvants to antigens, vaccine platforms, disease contexts, or populations. Advances in innate immunology and systems vaccinology have revealed early immune signatures associated with vaccine efficacy, but translating these insights into generalizable design rules has proven difficult due to context dependence, population heterogeneity, and the complexity of immune pathways. To address these limitations, the Division of Allergy, Immunology, and Transplantation (DAIT) within the National Institute of Allergy and Infectious Diseases (NIAID), a component of the U.S. National Institutes of Health, has established coordinated adjuvant discovery, development, and comparative research programs that emphasize standardized study designs, harmonized immune profiling, and cross-platform data integration that enable the systematic evaluation of adjuvant mechanisms and biological activities. Here, we examine conceptual and practical lessons emerging from DAIT/NIAID-supported programs and the adjuvant field more broadly, focusing on comparative immune profiling, adjuvant mimics, and combination adjuvants. Collectively, these efforts illustrate how harmonized datasets, shared infrastructure, and mechanism-guided analyses can transform adjuvant selection from an empirical process into a data-driven component of rational vaccine design, supporting precision immunomodulation across infectious, immunologic, and other non-infectious diseases.

RNA viruses have compact genomes that typically encode only a few proteins, but these viruses orchestrate complex replication cycles while concurrently exercising control over multiple aspects of the biology of the infected host cell, including the evasion of antiviral responses. Central to this functional diversity is the evolution of multifunctional proteins, which integrate diverse roles in replication and host subversion through structural, regulatory, and spatial versatility. The rabies virus P-protein exemplifies these principles. In addition to serving as an essential cofactor and chaperone in viral transcription and replication, the P-protein also antagonizes type I interferon responses, modulates intranuclear processes, and targets multiple host membrane-less organelles via liquid-liquid phase separation. These diverse functions are mediated by a combination of mechanisms, including expression as multiple isoforms, modular domain architecture, intrinsic disorder, dynamic subcellular trafficking, post-translational modifications, conformational plasticity, and RNA binding. In this review, we discuss established and recently emerging mechanisms underlying P-protein multifunctionality, which is likely to provide a model for understanding the&#xa0;multifunctionality of other viral, and likely cellular proteins. We also highlight how similar strategies are employed across RNA viruses to overcome genomic constraints, and discuss how these mechanisms may represent promising targets for future antiviral interventions.