Dried blood spots: A tool to ensure broad access to hepatitis C screening, diagnosis, and treatment monitoring

Abstract

Background. With the advent of highly efficient antiviral therapies for hepatitis C virus (HCV) infection, providing broad access to diagnosis and care is needed. The dried blood spot (DBS) technique can be used to collect, store, and ship whole-blood specimens. Our goal was to assess the performance of standardized HCV diagnostic and monitoring tools in the analysis of DBS. Methods. Serum specimens and whole-blood specimens collected using the DBS technique from >500 patients were tested for virological markers used to diagnose and monitor HCV infection. Results. Enzyme immunoassay detection of anti-HCV antibodies in specimens from DBS was reliable after establishment of a new signal-to-cutoff ratio. HCV RNA was detected DBS from the vast majority of patients with active replication, but HCV RNA levels were substantially lower than in serum specimens, implying that only the presence or absence of HCV RNA or changes in the HCV RNA level should be taken into consideration for therapy. Detection of HCV core antigen in specimens from DBS was not a sensitive marker of chronic HCV infection. HCV genotype determination was possible in the vast majority of DBS. Conclusions. This study shows that whole-blood specimens collected using the DBS technique can be confidently used to diagnose and monitor HCV infection. DBS could help improve access to care for HCV infection because they are suitable for use in largescale screening programs, diagnosis, and therapeutic monitoring.