IntroductionThe climate crisis presents a complex and growing challenge for healthcare systems around the world. Healthcare systems can contribute to substantial global emissions, with the UK's National Health Service (NHS) alone responsible for 4%-5% of the country's total carbon footprint. A wide range of clinical disciplines have already begun to assess and design interventions to tackle this issue. However, clinical and diagnostic laboratories remain underexplored.AimsWhat studies have been undertaken to assess and improve the environmental impact of clinical laboratories?MethodsThis scoping review undertook a multi-database search from date of inception to 5th February 2024. All primary studies that assessed the environmental outcomes of clinical laboratories were included. Studies were screened and data extracted by one reviewer with a 10% verification process at each stage. Studies were assessed based upon year of publication, geographical region, interconnectivity and area and type of clinical laboratory or test.FindingsThere has been some longstanding interest in understanding the environmental impact of clinical laboratories, and this field of investigation has gained popularity within the scholarly community in the last decade. Despite this recent increase in popularity there is a relatively limited number of intervention studies aimed at improving sustainability within clinical laboratories. Most research in this area originates from the United States, United Kingdom, and Australia, although the topic appears to be of global scholarly interest. There is limited interconnectivity of studies included in this review. Studies in this field have primarily been conducted at the clinical laboratory level, with a focus on quantifying waste in kilograms, measuring carbon dioxide equivalent (CO2e) emissions, and categorizing laboratory waste by type. To a lesser degree these outcomes have been assessed for specific clinical tests. Across both clinical laboratory and specific test assessments there is notable heterogeneity in both methods used, and areas explored.DiscussionWhile this scoping review highlights a growing interest and awareness in this important field, the diversity of reported outcomes and the limited interconnectivity of studies indicate that it remains a developing area. The lack of consensus in methodologies and outcome measures suggests that establishing a baseline analysis remains a distant goal. Ideally, future efforts should prioritize improving the assessment of individual laboratory tests, fostering greater standardization, and enhancing repeatability to strengthen the reliability of environmental impact evaluations.
BackgroundExposure of plasma to low temperatures induces the conversion of prorenin to renin, causing falsely elevated levels of renin. This also happens at storage temperatures of -20°C. Our survey evaluated the pre-analytical procedures used by clinical laboratories in the Netherlands for renin testing and assessed their awareness of recent studies on cryoactivation and their impact on pre-analytical procedures.MethodsA nine-question online survey about pre-analytical conditions for renin measurements in clinical laboratories was distributed by the Foundation for Quality Assessment in Medical Laboratory Diagnostics (SKML) to 106 clinical laboratories in the Netherlands participating in the external quality assessment scheme for hormone measurements.ResultsOf the 42 labs that responded, pre-analytical practices varied considerably. Time limits for sample receipt ranged from none (31%, n = 13) to <4 h (57%, n = 24) or >4 h (5%, n = 2). Most laboratories transported and centrifuged samples at room temperature (90% and 93%; n = 38 and 39). Storage conditions differed: 79% (n = 33) stored at -20°C, 17% (n = 7) at -80°C, 2% (n = 1) at -40°C, and 2% (n = 1) at room temperature. Twenty-two respondents (52%) were aware of recent literature, and 8 (36%) had changed or planned to change procedures accordingly. Overall, only eight laboratories (19%) followed all recommended steps to minimize cryoactivation.ConclusionsThis survey shows considerable inconsistency in pre-analytical procedures of renin testing in clinical laboratories in the Netherlands. Despite moderate awareness of recent evidence, implementation of optimal preanalytical procedures remains limited. The survey results show that guidelines and scientific evidence have not been fully implemented, and that awareness of the latest evidence does not directly lead to a change in practice.
BackgroundTotal protein (TP) is a key indicator to differentiate between pleural effusion (PE) and ascites as exudate or transudate. Rapid quantification of TP can provide more accurate clinical treatment.ObjectiveThis study developed a smartphone-based colorimetric method for the rapid quantification of TP in PE and ascites by measuring the RGB values of reaction products and establishing a correlation between these values and TP concentration.MethodsThe smartphone colorimetric system was validated according to Clinical and Laboratory Standards Institute (CLSI) guidelines, assessing precision, accuracy, detection limit, linearity, and clinical reportable range. To evaluate clinical applicability, we compared results from 43 clinical samples (12 ascites and 31 PE specimens) obtained using the smartphone system with those from an automated biochemical analyzer.ResultsThe G value showed the strongest correlation with TP concentration and was used to generate the standard curve. Validation studies confirmed that the smartphone system's precision and accuracy met clinical requirements, with analytical performance parameters including a limit of blank (3.36 g/L), limit of detection (8.94 g/L), and limit of quantification (13.09 g/L). The method demonstrated good linearity (15.8-93.7 g/L) and a wide clinical reportable range (13.09-374.8 g/L). Deming regression showed excellent agreement with no significant bias. The smartphone-based method and biochemical analyzer achieved near-perfect concordance in differentiating exudative and transudative fluids (PE κ = 0.92, ascites κ = 1.00).ConclusionThe smartphone-based colorimetric system provides a clinically viable solution for the rapid and quantitative measurement of TP in PE and ascites.
BackgroundArtificial intelligence (AI) is increasingly recognized as transformative in laboratory medicine, yet adoption lags behind radiology and cardiology. Limited data exist on AI-related attitudes and perceived barriers in Turkish clinical laboratories. This study evaluated professional awareness, attitudes, and perceived barriers to AI adoption among Turkish clinical laboratory professionals.MethodsA cross-sectional survey was conducted among Turkish clinical biochemistry staff between May and June 2025. The 30-item questionnaire covered demographics, AI knowledge, training, current use, future perspectives, and ethical or legal concerns. In total, 170 eligible participants, including laboratory directors, physicians, residents, and technologists, completed the survey.ResultsAmong the participants, 43% self-rated their AI knowledge as "basic," with no participant aged ≥60 years reporting good or expert-level knowledge. The greatest knowledge deficits were in image processing (49.4% reported "no knowledge") and predictive analytics (35.9%). More than half (57.6%) had never received AI-related training, and current use of AI tools in routine practice was minimal. Despite these gaps, attitudes toward AI implementation were overwhelmingly positive, with 75.3% believing increased AI use would improve job satisfaction and 59.4% expecting laboratory transition to AI-supported systems within 5 years. Major barriers included insufficient digital infrastructure (47%), absence of trained personnel (83.5%), lack of standard operating procedures (70%), and inadequate legal/ethical regulations (52.9%).ConclusionsAI implementation in Turkish clinical laboratories remains at an early stage but is met with strong professional interest. Overcoming structural barriers through standardized education, infrastructure investment, and clear legal frameworks is essential for sustainable AI implementation in clinical laboratories.
BackgroundThe NHS accounts for approximately 4-5% of England's total carbon footprint and was the first healthcare organisation to commit to a net-zero target. Reducing the inappropriate use of diagnostic tests could play a meaningful role in reaching this goal. In 2024, the microbiology laboratory at Lancashire Teaching Hospitals NHS Foundation Trust received >90,000 urine and >15,000 wound samples. Local audit data highlights samples are sent for testing in the absence of clinical signs and symptoms of infection. Furthermore, 25 % of superficial swabs and 10% of urines grew mixed-faecal organisms.PurposeThe aim was to implement a diagnostic stewardship intervention to reduce inappropriate urine and wound swab submissions from primary care and estimate associated carbon savings.Research DesignA pre-analytical stage diagnostic stewardship intervention was implemented consisting of a computerised clinical decision support tool (CCDS). The tool prompts clinicians, using evidence-based guidance, on when to obtain samples for testing. Study Sample: 3-month intervention period data was compared with two 3-month pre-intervention periods (I and II).Data AnalysisThe UK Government 2024 greenhouse gas conversion factors were used to calculate the total CO2e associated with testing urine and wound samples. ResultsComparing number of samples received during the intervention period with pre-intervention II, urine samples decreased by 10.2%, saving 190.5 kg CO2e. Similarly, wound samples decreased by 12.9%, saving 80 kg CO2e.ConclusionThe CCDS tool effectively reduced unnecessary testing and associated carbon emissions, supporting the NHS's net-zero ambitions. Similar tools can be employed in other areas of pathology to reduce the impact of inappropriate testing whilst supporting sustainable healthcare.
Chagas disease is a neglected tropical disease caused by the protozoan Trypanosoma cruzi, primarily transmitted by infected bugs, but also through contaminated food, transfusions, congenital transmission, and organ transplantation. Chagas disease has acute and chronic phases; the chronic phase can occur decades after infection, leading to complications such as heart failure, arrhythmias, and megaviscera. Accurate mortality and morbidity estimates are hindered by under-reporting and misclassification. Comprehensive and updated estimates are needed to improve global assessments of Chagas disease burden. We aim to provide a comprehensive description of global and regional burden of Chagas disease and its trends from 1990 to 2023. In this systematic analysis for the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2023, we produced estimates of Chagas disease deaths, years of life lost (YLLs), prevalence, incidence, years lived with disability (YLDs), and disability-adjusted life-years (DALYs) for 204 countries and territories from 1990 to 2023 by age and sex. The GBD 2023 estimates supersede previous estimates for all years. For mortality estimates, we fit a cause of death ensemble model to vital registration data. For non-fatal estimates in endemic locations, we did a systematic review of seroprevalence data, defining a confirmed case as a confirmed diagnosis of T cruzi infection by two different positive tests (or a single ELISA or immunochromatographic test). After adjustment for the population at risk, we used a Bayesian compartmental model (DisMod-MR) to produce estimates. For non-endemic locations, we estimated prevalence on the basis of migration patterns and estimated prevalence from endemic countries. Prevalence of acute and chronic sequelae and corresponding disability weights were used to calculate YLDs. We estimated 10·5 million (95% uncertainty interval 9·4-11·7) Chagas disease prevalent cases in 2023 globally, a 16·1% (12·6-19·2) decrease compared with 1990. The global age-standardised Chagas disease prevalence rate declined by 55·0% (53·8-56·1) from 1990 to 2023, with rates decreasing across all endemic regions. The highest age-standardised Chagas disease prevalence rates in 2023 were in southern Latin America (2485·9 [2249·6-2707·7] per 100 000) and Andean Latin America (2313·8 [2093·7-2570·1] per 100 000). Non-endemic regions experienced notable increases in prevalence due to migration from endemic countries. The age distribution of cases shifted over time, peaking at older ages in 2023 (between age 45 years and 65 years) compared with 1990 (30-45 years). In 2023, there were 352 000 (308 000-398 000) new cases of Chagas disease globally, with the age-standardised rate decreasing by 55·1% (53·4-56·6) since 1990. There were 8420 (7480-9360) deaths globally in 2023. Age-standardised mortality decreased by 72·5% (68·9-75·4) globally from 1990 to 2023. In 2023, the highest age-standardised mortality rates were in tropical Latin America (2·2 [1·9-2·4] per 100 000) and Andean Latin America (0·92 [0·70-1·2] per 100 000). The GBD 2023 Chagas disease estimates are notably higher than previous GBD estimates, reflecting additional data and methodological improvements, and those published by the Pan American Health Organization. Nevertheless, these updated estimates show decreasing prevalence and incidence in endemic countries, highlighting the importance of socioeconomic development, housing conditions, and vector-control policies. Conversely, the increase in prevalence in non-endemic countries, mainly due to migration, requires new strategies for screening, early recognition, and access to care. Although the marked decrease in mortality and YLLs might be due to better access to care at different levels, the shift in age distribution highlights the importance of preparing and funding health systems for caring for older populations with advanced sequelae. Finally, the continuous refinement of data-source quality, including adequate coding and classification, is crucial for the accuracy of global estimates, which can ultimately drive health and social policies. The Gates Foundation, the World Heart Federation, and Novartis Pharma.
BackgroundCerebrospinal fluid (CSF) spectrophotometry is well-established in the UK for measuring CSF bilirubin and oxyhaemoglobin to aid in the diagnosis of subarachnoid haemorrhage. Although it is known that some antibiotics and large amounts of oxyhaemoglobin interfere in the spectrophotometric analysis of CSF bilirubin, there is little published evidence about the impact of such interferences.MethodsExperimental samples were distributed to participants in the UK National External Quality Assessment Service (NEQAS) for Immunology, Immunochemistry and Allergy EQA programme for CSF haem pigments. Distribution 244 consisted of a pair of matched samples but with sample 244-2 containing an increased amount of oxyhaemoglobin compared to sample 244-1. Distribution 251 consisted of a pair of matched samples but with sample 251-2 containing additional doxycycline at a concentration of 0.5 µg/mL compared to sample 251-1. Participants analysed the samples spectrophotometrically and absorbance values were returned to UK NEQAS.ResultsThe net bilirubin absorbance (NBA) was significantly reduced in the presence of both interferants; adding 0.6% oxyhaemoglobin decreased the NBA by a mean of 55.9% and adding 0.5 µg/mL doxycycline decreased the NBA by a mean of 14.3%. Wilcoxon signed rank tests showed the NBA was significantly different for sample 2 compared to sample 1 for both distributions.ConclusionsIncreased amounts of oxyhaemoglobin and the presence of doxycycline can both negatively interfere with NBA. The interference is subtle and difficult to detect but has the potential to change a true positive result to a false negative, highlighting a significant limitation of the CSF spectrophotometry technique.
Cryoglobulins are proteins that are temperature sensitive, precipitating at temperatures below 37°C, and dissolve upon rewarming. However, at lower temperatures cryoglobulins can result in damage subsequently leading to vascular compromise. We present a case of a patient with a known lymphoplasmacytic lymphoma. The patient developed extensive finger necrosis and toe necrosis. Cryoglobulin was requested and a small type I was found. Given how common type I cryoglobulins are, more evidence was needed that this was the underlying aetiology of the necrosis. A biopsy of the tissue immediately proximal to the necrosis was performed. Histological evaluation confirmed cryoglobulin occlusions. Given the small cryoglobulin level, we assume the thermal amplitude of this resulted in this degree of vascular damage. Thermal amplitude of cryoglobulins is not generally performed. However, we know from testing the thermal amplitude of the red cell agglutination that the more active the antibody is at higher temperatures like those experienced in both the central and peripheral circulation, the more clinically significant the haemolysis. As this lady had chronic stable haemolysis, we sent the sample to the red cell reference lab to investigate the thermal range of the red cell antibody. This was checked at 4°C, room temperature, and 37°C. The cold antibody titre was 65536 at 4°C, 2048 at room temperature, and 1 at 37°C. This activity, despite having large titres at the cold range, demonstrated a wide thermal amplitude. Therefore, given these findings it is likely that the cryoprecipitate within the plasma had a similarly high thermal range.
BackgroundAlbuminuria is an early marker of kidney damage and an essential component of chronic kidney disease (CKD) risk stratification. Quantitative measurement of the urine albumin-to-creatinine ratio (ACR) in a spot, preferably morning, urine sample is the recommended standard. In low-throughput laboratories and point-of-care settings, semi-quantitative strip tests are sometimes used for screening, although their diagnostic performance is limited.ObjectiveTo evaluate the clinical utility of a commercial semi-quantitative urine strip test for albumin and creatinine by comparison with quantitative ACR measurement.MethodsEighty-four spot urine samples were analysed. Semi-quantitative ACR categories were obtained using an ACON Mission strip test, according to the manufacturer's instructions. Quantitative ACR was measured on a Beckman Coulter AU480 analyser (immunochemical albumin, enzymatic creatinine). Diagnostic performance was assessed using sensitivity, specificity, positive and negative predictive values, Matthew's correlation coefficient (MCC) and Cohen's κ. A decision threshold of 3 mg/mmol (30 mg/g) was applied.ResultsSensitivity for detecting albuminuria (≥3 mg/mmol, ≥30 mg/g) was 80.6% (95% CI 62.5-92.5) and specificity was 60.4% (95% CI 46.0-73.5). The negative and positive predictive values were 84.2% and 54.3%, respectively. Overall categorical agreement across A1-A3 was 63.1% (κ = 0.334; MCC = 0.398). Most discrepancies reflected overclassification of low-grade albuminuria by the strip test in samples classified as normoalbuminuric by quantitative ACR.ConclusionsThe semi-quantitative strip test shows high sensitivity with moderate specificity and is suitable for screening for albuminuria. Positive results should be confirmed by quantitative ACR measurement in accordance with current guidelines.
BackgroundBiotin is commonly used in many commercial assays. It is known that exogenous biotin can interfere with these tests, however, not all manufacturers have issued warnings or reassurances. Interference can lead to increased or decreased concentrations of an analyte depending on the assay format. We assessed the effect of biotin interference on all relevant assays performed in our laboratory. We investigated a variety of concentrations ranging from the recommended daily intake up to very high dose supplementation to determine the level at which a particular assay may be affected.MethodsSamples were spiked to give estimated serum concentrations equivalent to doses of 0.05-3600 mg/day exogenous biotin. Each spiked sample was tested and the result compared to a baseline. Biotin interference was deemed to have taken place if the spiked value exceeded the allowable uncertainty of measurement.ResultsNot all assays utilising biotin were affected. We confirmed interference claims made by Manufacturers. However, a few of these assays showed that biotin levels below those stated in safety notices could cause some degree of interference. Three assays for which there had not been a warning were shown to be affected.ConclusionsIn house checks should be performed on all assays containing biotin as a reagent. This allows the laboratory to understand performance characteristics and dosage effects for causing potential interference. Our data provides a guide for the level of biotin which may cause false positive or false negative results.
BackgroundPoint of care (POC) tests may improve accessibility and reduce costs of blood tests including in prostate cancer. The Man Van project was a pilot designed to address health inequalities that affect prostate cancer with novel community-based targeting of high-risk groups on a mobile clinical unit.MethodsThe i-CHROMA-II™ POC machine is a quantitative assay for the measurement of total prostate specific antigen (PSA) from capillary blood using fluorescence immunoassay technology. Laboratory based Serum PSA testing was compared with capillary blood POC testing using the i-CHROMA-II™ to determine its accuracy and impact on clinical decision making on the Man Van.Results28 men participated. The median age was 53 years (range 45-74). One POC test result was invalid. Nine POCT samples gave a result of <0.5 μg/L and were not included in the analysis. Of the remaining results (N = 18) the median PSA was 1.97 μg/L (range 0.54-31.22 μg/L). Using Lin's Concordance Correlation Coefficient of Absolute Agreement gave a value of 0.392 (N = 17). A Bland-Altman plot showed a mean difference of 0.377 μg/L.ConclusionsWe report the first testing of PSA using the i-Chroma-II™ machine, and the first real-world mobile testing using any POC PSA test. Our study did not show correlation between the laboratory and i-Chroma-II™, although it did replicate the positive bias seen in previous studies. Further testing and refinement of POC tests may help to achieve the goal to developing reliable POC PSA tests.
BackgroundThe Japanese Red Cross Society measures levels of glycated albumin (GA), an indicator of mean blood glucose levels, in blood obtained from all donors.MethodsChanges in mean GA levels and the percentage of cases of prediabetes from 2009 to 2018 were investigated in approximately 4.2 million, healthy, first-time blood donors aged 16-64 years, and the seasonal characteristics of GA and the association of the GA level with body mass index (BMI) were clarified.ResultsMean GA levels decreased over the decade, with a decrease of 0.42-0.77% in male and 0.39-0.49% in female donors in the groups categorised by age. The percentage of prediabetes cases also decreased over the decade, with the largest decrease in those in their 60s. GA levels were higher in the warm season than in the cold season. In 2018, the seasonal difference in the GA level was 0.48% (95% confidence interval [CI] 0.45-0.50%) for male and 0.45% (95% CI 0.41-0.48%) for female donors. GA had a linear negative correlation with BMI in the younger generation. A trend of increasing GA with BMI was noted in those in their 30s and older.ConclusionsMean GA levels and the percentage of prediabetic cases have decreased, possibly resulting from public health promotion efforts and early diagnosis of diabetes mellitus. The present data on GA seasonal variation, showing higher levels in the warm season, and the association between BMI and GA may be useful for clinical practice.
A 37-year-old woman attended hospital with melaena and coffee-ground vomiting on a background of alcohol-related liver disease (ALD). Following upper gastro-intestinal (GI) endoscopy she was admitted to the medical high dependency unit and commenced on multiple medications, in accordance with the decompensated cirrhosis care bundle of the British Association for the Study of the Liver (BASL).1 The patient was severely encephalopathic, prompting the addition of regular enemas to minimise colonic nitrogen production. On Day 4 post admission, the patient was noted to be hypocalcaemic (adjusted calcium 1.62 mmol/L) and intravenous calcium gluconate was prescribed. By Day 5, adjusted calcium had fallen to a nadir of 0.85 mmol/L; phosphate was 6.4 mmol/L. The rapidly developing inverse relation between calcium and phosphate strongly suggested a causal association. Since Day 3 the patient had received enemas three times daily for severe hepatic encephalopathy. We postulated that rectal absorption of phosphate in the enemas was occurring, contrary to the intended mechanism of action, and recommended they were stopped. Following discontinuation of the phosphate enemas, serum phosphate fell to within the reference range over 72 h. In total, over 70 mmol of calcium (infused as 280 mL of 10% calcium gluconate over a period of 5 days) was required to replace the sequestered calcium. By Day 11, calcium, phosphate and sodium were all within their respective reference ranges.
BackgroundVitamin B12 deficiency can cause anaemia, fatigue, and neurological sequelae. Total B12 assays may not be reflective of tissue B12. Methylmalonic acid (MMA) can assess tissue B12 more accurately. NICE published clinical guidelines on Vitamin B12 deficiency in adults in 2024. They outlined MMA testing in two scenarios: in patients where nitrous oxide use is possible or who have an indeterminate total B12 result (180-350 ng/L) alongside symptoms or signs of B12 deficiency. MMA testing is costly, not readily available, and time consuming, so increased use will have implications.MethodsThis is a Case note review of patients who had MMA requested one year prior to and one year post-NICE NG239 publication. Audit standards followed were NG239 indications for MMA testing.ResultsIn the year after NG239, MMA testing increased by 96% (57 to 112). Whilst only 47% would have meet NG239 testing criteria in the prior group, this increased to 79% in the post group. More were diagnosed with B12 deficiency (16% prior and 21% post), and more commenced on B12 treatment (14% prior and 19% after). Comparing simultaneous total B12 and MMA results suggests an increase in the upper reference interval of the indeterminate range to 375 ng/L could be considered.ConclusionsDemand for MMA testing almost doubled after NG239 was published, though requests appeared much more appropriate. Whilst laboratory costs increased, there may have been savings elsewhere in the system. Further analysis would be required to review the extent of these healthcare savings in practice.
The presence of paraproteins in multiple myeloma can cause analytical interference, resulting in unusual and misleading biochemical outcomes. An uncommon but clinically relevant finding is the reporting of a negative direct bilirubin result on wet chemistry analyzers-an impossible outcome that strongly suggests analytical interference. A 60-year-old male presented with nonspecific symptoms. Liver function tests carried out on a wet chemistry analyzer indicated a total bilirubin of 0.39 mg/dL and a direct bilirubin of -7.67 mg/dL, which was not physiologically possible. There was no evidence of jaundice, and imaging appeared normal. Repeat testing with a dry chemistry analyzer indicated a total bilirubin of 1.0 mg/dL and a direct bilirubin of 0.1 mg/dL, aligning with the clinical picture. Further investigations confirmed the diagnosis of multiple myeloma with IgG-kappa monoclonal gammopathy. The discrepancy was attributed to paraprotein interference in the wet chemistry method. This case highlights a rare but important laboratory artifact-negative direct bilirubin due to paraprotein interference-and emphasizes the reliability of dry chemistry in such scenarios. Awareness of this interference is important for accurate diagnosis and avoiding unnecessary workup.
ObjectivesAcidification of urine samples has long been used as a method of preservation to enhance analyte stability. However, there are inherent safety risks to staff and patients when acid preservatives are used. The Association of Laboratory Medicine National Audit Committee sought to assess urine acidification practices in NHS laboratories.MethodAn 11 question survey was sent to all Association of Laboratory Medicine members for completion between 24th January 2023 and 24th February 2023 and data analysis performed using Microsoft Excel. For a variety of analytes, laboratories were asked to detail the type of recommended and accepted collection containers, whether 24 h and/or spot urine samples were accepted, if preservative was added to samples on receipt if not collected with preservative and the storage conditions for unpreserved samples.Results69 laboratories responded. Safety information was provided to users by the majority of laboratories and 88% of laboratories would pH test samples prior to sending them to a referral laboratory if acidification was a prerequisite. Variation was noted in quoted time of sample stability when refrigerated. Laboratories provided answers about specific tests - sodium, potassium, osmolality, calcium, magnesium, phosphate, creatinine, Bence Jones protein, total protein, urate, citrate, oxalate, cysteine, catecholamines, metanephrines, 5-HIAA, VMA/HMMA, copper, amino acids, organics acids and glycosaminoglycans.ConclusionsThere is significant variation in the use of acid as a preservative for urine samples throughout NHS laboratories as well as historical requirements for urine acidification for certain analytes which evidence has indicated is no longer a requirement.
Case oneA young woman presented to the Early Pregnancy Assessment Unit (EPAU) with abdominal pain, amenorrhoea and variably positive home-pregnancy tests. On review, a point-of-care test (POCT) for urine beta-HCG (β-HCG) was negative but a blood test using the Abbott i-STAT β-HCG POCT device was positive. Initial transvaginal ultrasound did not demonstrate an intra- or extra-uterine pregnancy. Over the following 2 months, weekly plasma POCT iSTAT β-HCG checks remained positive. After a further ultrasound suggesting a possible ectopic pregnancy, the patient underwent a diagnostic laparoscopy which was unremarkable. Post-operatively, POCT iSTAT β-HCG levels remained elevated, and a blood sample was sent for laboratory analysis revealing an undetectable β-HCG of <1.20 IU/L (reference interval 0-4).Case twoA middle-aged woman presented to the emergency department with mons pubis pain and swelling and was admitted to the gynaecology ward for drainage of bilateral abscesses. On review, she had raised blood β-HCG levels, measured using the Abbott i-STAT POCT device. A subsequent blood sample sent for laboratory analysis showed β-HCG levels within the post-menopausal reference interval. Discussion: In both cases, POCT immunoassay interference was confirmed by consistent results produced when contemporaneous samples were analysed by different analytical platforms. Immunoassay interference, though rare, can lead to inaccurate results from POCT devices, potentially impacting patient diagnosis and management. Clinical teams should remain vigilant for this possibility; if test results do not align with clinical expectations, it is essential to promptly send a blood sample for laboratory analysis.
Venepuncture is traditionally regarded as the gold standard for collecting blood samples. However, self-collected capillary blood sampling has emerged as a practical alternative in various settings, fostering a more patient-centred, personalised, and cost-effective healthcare model. The NHS UK strategic plans published in 2023-2025 emphasise a shift in care from hospitals to community settings and from treating illness to preventing it. Self-collected capillary sampling with back-to-laboratory analysis is a strong option to support the shift of healthcare provision into the community while maintaining high-quality results and direct delivery to the electronic patient record.Routine clinical laboratories, particularly those within the NHS, should consider this potential delivery model. However, most assay manufacturers do not currently include capillary blood in their instructions for use. Consequently, UK Accreditation Service-accredited laboratories that wish to conduct routine tests using capillary blood must perform additional comparison studies to obtain accreditation. If this is not done, they must be able to distinguish between non-accredited (capillary blood) and accredited (venous blood) tests.This document has been created to guide clinical laboratorians through the rapidly evolving field of patient-centric sampling and how to enable safe working within a routine clinical laboratory.
BackgroundStatistical quality control continues to serve as the cornerstone for ensuring the accuracy and reliability of laboratory investigations. The current research aimed to evaluate the performance of biochemistry parameters using Six Sigma metrics in light of revised CLIA (Clinical Laboratory Improvement Amendments) total allowable error (TEa) 2024 guidelines, to guide the application of appropriate quality control strategies.MethodsQuality control data for 20 chemistry parameters analyzed on the Fully Automated Biochemistry analyzer were evaluated using Six Sigma methodology. Internal quality control (IQC) and external quality assessment scheme (EQAS) data from December 2023 to May 2024 were collected. Coefficient of variation (%), bias (%) and TEa based on CLIA and Ricos biological variation guidelines were used to calculate sigma metrics. All quality control data were entered and analyzed using Microsoft Excel (Microsoft Corporation, Redmond, WA, USA).ResultsThe laboratory showed excellent (≥6 sigma) performance for direct bilirubin and HDL-cholesterol. Albumin, alkaline phosphatase, aspartate transaminase, cholesterol, glucose, iron, potassium, total iron-binding capacity and triglycerides achieved minimum sigma performance standard (>3) at one level. However, the other chemistry parameters did not meet the minimum sigma performance standard across all assay range.ConclusionThe laboratories need to reassess the performance of various biochemical parameters to redefine quality control protocols as the CLIA 2024 guidelines have tightened the total allowable error goals.
IntroductionWhile conclusions regarding the effects of serum separator tubes on some laboratory tests have been reached in previous studies, the effects of these tubes on the B12 test have not been adequately investigated. This study aimed to determine the effects of the serum separator tube position after centrifugation on serum B12 test results.Materials and MethodsTwo blood samples were collected by venipuncture into 5-mL Pirmax serum separator tubes from each of the 30 volunteers. The effects of the tube position after centrifugation, gentle mixing 5-10 times, recentrifugation, and short-term (15 min) standing of the tubes in an upright position on serum B12 test results were examined in a step-by-step manner. The B12 analyses were performed in an ADVIA Centaur XPT autoanalyzer using a chemiluminescence method. Comparisons between the groups were evaluated for statistical and clinical significance.ResultsB12 levels were higher in the samples positioned horizontally than in the samples positioned vertically (P < 0.001). The total effect of horizontal position and mixing was abolished by recentrifugation (P = 0.091). The horizontal tube position and sample mixing led to an exceedance of the total allowable error limit.ConclusionsThe use of serum separator tubes may be associated with spuriously elevated serum B12 concentrations in the ADVIA Centaur XPT assay. The serum separator tubes should be kept upright in the post-centrifugation period prior to B12 analysis. We recommend recentrifugation if the tubes have been held in a horizontal position and/or the samples have been mixed.