Improved serodiagnosis of posttransfusion hepatitis C virus infection by a second-generation immunoassay based on multiple recombinant antigens.

Serial serum samples from 35 patients with posttransfusion non-A, non-B hepatitis in a prospective study were tested for antibody to hepatitis C virus (HCV) by a multiple recombinant antigen based immunoassay [anti-HCV (2nd); Abbott]. Of them, 23 were positive for anti-C100, and 27 were positive for HCV RNA by polymerase chain reaction. By anti-HCV (2nd), 28 patients were positive, and all except 1 of the 28 patients were positive for HCV RNA. A total of 24 patients, who became HCV RNA positive at the acute stage and who were negative for both anti-C100 and anti-HCV (2nd) before transfusion, were considered to have posttransfusion hepatitis C. The mean time to seroconversion for anti-HCV (2nd) was 7.5 or 12.1 weeks after the onset of hepatitis or the date of transfusion, respectively, and was generally 6 weeks earlier than that detected by anti-C100. However, seroconversion was delayed in 2 hepatitis B surface antigen carriers as compared with anti-C100. The anti-C100 assay detected 20 (83%) and the anti-HCV (2nd) all 24 patients with documented posttransfusion hepatitis C. The second-generation test is, therefore, better than conventional anti-C100 for the early diagnosis of HCV infection.