Comparison of Antibody Confirmation Assays for Hepatitis C Virus Testing in Patients With HIV

The World Health Organisation recommends testing populations most affected by hepatitis C virus (HCV) infection, like people living with HIV. After screening with an Ab test, HCV RNA testing is required to identify active (viremic) infections. One could focus the HCV RNA testing capacity on true positive serological test results, by implementing serological HCV confirmation assays. Our goal was to evaluate the performance of 3 HCV confirmation assays in people living with HIV.

A total of 415 frozen plasma specimens collected in Cambodia (Sihanouk Hospital Center of HOPE) and Belgium (Institute of Tropical Medicine) were tested with Geenius HCV supplemental Assay (Bio-Rad, Marne la Coquette, France), HCV Blot 3.0 (MP Biomedical, Irvine, CA), and INNO-LIA HCV Score (Fujirebio, Ghent, Belgium). Results were compared against HCV RNA results and/or a composite reference standard.

Overall, INNO-LIA had the highest sensitivity (97.0%; 95% confidence interval [CI], 94.0%-98.5%) and Geenius the highest specificity (98.2%; 95% CI, 93.7%-99.5%). In a subset of patients with active infection (n = 177), all 3 assays showed comparable sensitivity (99.0%; 95% CI, 96.0%-100.0%). Both for INNO-LIA (8.7% [36 of 415]) and HCV Blot (7.0% [29 of 415]), the indeterminate results were mostly negative and/or indeterminate (80.6% [29 of 36] and 93.1% [27 of 29], respectively) on the composite reference standard compared with only 26.3% (10 of 38) on Geenius.

All 3 antibody confirmation assays show comparable and high sensitivity in active HCV infections. Geenius potentially offers some advantages in ease of use, low turnaround time, and ruling out past infections. The added value of HCV antibody confirmation assays needs to be established in larger cost-effectiveness studies and is influenced by decreasing HCV prevalence and HCV RNA capacity.