Presence of Detectable HCV-RNA in the Absence of Positive HCV Serology in Blood Donors Infected with HTLV-I/II

We have studied hepatitis C virus (HCV) infection among 100 blood donors with positive or indeterminate test results on Western blot for human T-cell lymphotropic virus (HTLV-I). Twelve (12%) of the donors were positive for antibodies to HCV; 7 of them were coinfected with HTLV-II and 4 were negative on HTLV-I/II polymerase chain reaction (PCR). None of the HTLV-I infected donors were positive for HCV. RNA PCR for HCV was performed and 2 of the positive donors were negative for antibodies to HCV. The donors were recalled for further studies. Two of the returning donors remained consistently positive on PCR for the 5′ noncoding region (5′NC) of HCV and negative on antibody assays a year after the initial tests, a period that should have been sufficient for seroconversion to occur.