Comparative study on anti-HCV testing using plasma, dried plasma spots (DPS), and dried blood spots (DBS)

The aim of this study was to evaluate the performance of an assay using dried plasma spot (DPS) and dried blood spot (DBS) samples for the serological detection of anti-hepatitis C virus (HCV) antibodies. Between January and July 2019, plasma, DPS and DBS specimens were collected from individuals at high-risk for HCV infection. Samples were tested for anti-HCV by ELISA, and the performance of DPS and DBS specimens was examined using results from the plasma testing, as the standard. Blood samples were collected from 329 persons, including 129 men who have sex with men and 200 intravenous drug users. Results from the plasma testing indicated that 118 samples (59.0%) were HCV positive. Data from the DPS sample testing showed sensitivity as 99.2% (95% confidence interval [CI]: 0.95–1.00) and specificity as 100% (95% CI: 0.98–1.00) for HCV detection, with Kappa of 99.3% (95% CI: 0.98–1.00) while in DBS sample testing the sensitivity as 98.3% (95% CI: 0.93–1.00) and specificity as 100% (95% CI: 0.98–1.00), with Kappa of 98.7% (95% CI: 0.97–1.00), respectively. Spearman’s correlation coefficients for the comparisons between plasma and DPS specimen, plasma and DBS specimens, DPS and DBS specimens were 0.857, 0.750, and 0.739, respectively. Compared with the results in plasma, 1 sample was not detected using the DPS specimens, and 2 samples were failed for the positive detection, using the DBS specimens. Both DPS and DBS samples were promising alternatives to plasma, for the detection of anti-HCV antibodies.