Evaluation of a supplemental assay for the diagnosis of hepatitis C virus infections

Objectives: A supplemental test was evaluated for hepatitis C virus (HCV. Methods: One hundred forty-six sera that were inconclusive or discrepant in two screening tests for HCV infection were evaluated using a supplemental test, MATRIX-HCV2™ (Abbott Laboratories, Chicago, IL, USA). Results of the supplemental test were compared to the detection of HCV RNA by a nested polymerase chain reaction after a step of reverse transcription (RT-PCR). Results: Thirty-nine RNA-containing sera (positive with RT-PCR) of 40 (97%) reacted with at least one antigen in the supplemental test. Reactivity with one to three antigens also was observed with 77 PCR-negative sera (66%). Twenty-nine sera were found negative with both techniques. Conclusions: Despite clear results and good sensitivity, the MATRIX-HCV2™ assay was poorly predictive of viremia in patients with indeterminate results in initial screening assays.