Sensitivity of a modified version of the ARCHITECT® Anti-HCV test in detecting samples with immunoblot-confirmed, low-level antibody to hepatitis C virus

Background and objectivesCompliance with current regulations regarding the prevention of hepatitis C virus (HCV) transmission in the blood transfusion setting requires the use of sensitive assays for HCV antibody (anti-HCV) detection, which should, ideally, identify any donor having had prior contact with the virus. Therefore, low-level anti-HCV positive blood units should be detected by the screening assays, even those reflecting a past and resolved infection. To assess the sensitivity of two versions of an automated chemiluminescent microparticle immunoassay (CMIA) for anti-HCV screening (ARCHITECT® Anti-HCV), 113 single serum samples containing low levels of anti-HCV, assessed by two immunoblot tests, were selected from 3686 samples received for confirmation of HCV infection by a reference laboratory over a 2-year period.Materials and methodsThe panel included 17 samples with HCV RNA detected by the polymerase chain reaction (PCR) and 96 PCR negative samples with either positive or indeterminate (anti-Core and anti-NS3 alone) results by immunoblot.ResultsAll but 13 specimens (100/113, 88.5%) were detected by the current version of the ARCHITECT® Anti-HCV assay and 10 additional samples (110/113, 97.3%) tested positive in a modified version of the test.ConclusionThe results showed that the modification introduced in the ARCHITECT® Anti-HCV assay achieves a significant sensitivity improvement including samples with low-level anti-HCV which are either PCR positive or negative.