Dried Blood Spot: A Tool to Ensure Broad Access to Hepatitis D Screening, Diagnosis, and Treatment Monitoring.

内容摘要

Chronic hepatitis D is the most severe form of viral hepatitis. Despite recommendations for systematic screening of HBsAg-positive individuals, hepatitis D infection remains underdiagnosed. Standard HDV virological markers are classically assessed in serum or plasma specimens obtained through venous whole blood sampling. This approach is costly and challenging in resource-limited settings. Dried blood spot (DBS) sampling offers a practical alternative for large-scale screening, diagnosis, and monitoring of viral hepatitis. The goal of the study is to evaluate the performance of commercially available HDV diagnostic assays using DBS. Plasma and DBS-collected whole blood specimens from individuals chronically infected with HBV or coinfected with HBV and HDV were analysed for HDV antibody detection, HDV RNA quantification, HBsAg levels, and HDV genotyping. HDV antibodies were reliably detected in DBS after threshold adjustment, with the LIAISON XL Murex Anti-HDV assay showing superior sensitivity (99.3%) compared to HDV Ab DIA.PRO (90.3%), while both assays exhibited excellent specificity. HDV RNA was quantifiable in 86.8% of DBS specimens from patients with active infection, although levels were about 1.5 log10 lower than plasma, showing a strong correlation (r&#x2009;=&#x2009;0.786; p&#x2009;<&#x2009;0.0001). HBsAg was detectable and quantifiable in all DBS samples, correlating closely with plasma values (r&#x2009;=&#x2009;0.98). DBS-based HDV genotyping was successful in 84.8% of samples and concordant with plasma results. DBS collection of whole blood from DBS appears to be a promising and practical alternative to conventional venous blood sampling for HDV screening, diagnosis, and monitoring. DBS sampling is a valuable tool for the large&#x2010;scale screening, diagnosis, and monitoring of viral hepatitis B and C. HDV virological markers can be easily detected in the whole blood. Collecting whole blood on filter paper offers a practical approach that could significantly contribute to the WHO's goal of eliminating viral hepatitis.