Sensitivity and specificity of dried blood spot samples for hepatitis C virus RNA testing

Dried blood spot (DBS) samples can improve access to hepatitis C virus (HCV) testing among hard-to-reach and underserved populations. We conducted a multicentre diagnostic accuracy study to evaluate the clinical performance of the Abbott RealTime HCV assay on the m2000 platform for detecting HCV RNA, using a standardized DBS collection and elution protocol.

The study was conducted at four sites in Cameroon, Rwanda, Georgia and Greece. DBS prepared from capillary and venous blood samples were collected from three target populations; individuals at risk of HCV infection, persons living with HCV, and individuals previously treated for HCV. Plasma samples tested on the Abbott m2000 platform served as the reference standard.

A total of 936 participants were enrolled, of whom 76.6% were HCV antibody positive. Both capillary and venous DBS demonstrated high diagnostic accuracy. Sensitivity and specificity were 95.2% (95% CI: 92.9-96.8) and 95.6% (95%CI: 93.3-97.1) for capillary DBS, and 95.4% (95% CI: 93.1-97.0) and 96.0% (95% CI: 93.8-97.4) for venous DBS. The Abbot RealTime HCV assay on the Abbott m2000 platform showed strong clinical performance for detecting HCV RNA from DBS.

These findings support the use of DBS as a feasible and less resource-intensive alternative to plasma-based testing, potentially expanding HCV screening and diagnosis in decentralized settings. Reliable DBS testing relies on proper sample collection, appropriate handling, and adequate staff training.

NCT03896087 (registered on 14 March 2019) available here: Study Details | Evaluation of Dried Blood Spot for HCV RNA Testing | https://clinicaltrials.gov/ .