Background: Recent data on anti-HCV screening assays among large population of blood donors is limited. The present study aimed to perform a multicenter evaluation of EIAs and CLIAs for detection of anti-HCV among blood donors in 16 different Chinese blood establishments.
Methods: A total of 1,309 samples including 582 anti-HCV screening negatives and 727 positives collected from 15 blood establishments all over China. Ten different anti-HCV assays (eight EIAs and two CLIAs) were evaluated in 16 different blood centers/banks. Confirmatory testing was performed using recombinant immunoblot assay and HCV RNA tests.
Results: The plasma panel contained 963 negative samples, 261 positives, and 85 indeterminate samples, based on the results of confirmatory test. False positive rate of screening tests was 39.67% (382/963) and the positive prediction value was only 35.76% (260/727). Among ten anti-HCV assays, Roche and InTec had the highest sensitivity (98.47%), while KHB and Wantai (indirect) had the highest specificity (99.23%). Then we analyzed the combined performance of these assays with two assays’ strategy widely used in China: Ortho or Abbott together with InTec could find all the true positives and Wantai (indirect) with Livzon (sandwich) got a highest specificity of 97.80%. Indeterminate samples showed quite different signal to cutoff (S/CO) ratios tested by Roche compared with confirmed positives (4.84 vs 19.36, p<0.0001), and higher S/CO ratios than confirmed negatives (4.84 vs 2.94, p=0.020).
Conclusion: False reactivity in anti-HCV screening should be treated as urgent issue. RIBA indeterminate donations may be a special group, while it still worth to be further studied.