Recombinant immunoblot assay first and second generations on 732 blood donors reactive for antibodies to hepatitis C virus by ELISA. The Hepatitis Study Group of the French Society of Blood Transfusion.

A comparison between recombinant immunoblot assay hepatitis C virus (HCV) first generation (RIBA-1) and second generation (RIBA-2) was made on 732 blood donors reactive by anti-HCV ELISA (Ortho Diagnostics System) by the Hepatitis Study Group of the French Society of Blood Transfusion. RIBA-2 results were correlated with ELISA ratio and ALT levels. The number of both reactive and nonreactive samples was higher with RIBA-2 than with RIBA-1, 252 (34%) compared to 224 (31%) for reactive samples, and 404 (55%) compared to 307 (42%) for nonreactive samples. C 22-3 and C 33-c reactivities were observed in 96 and 91% of the reactive samples, respectively. A total of 76 samples (11%) remained indeterminate by RIBA-2, 84% of them reacting only on C 100-3 antigen. A clear relationship between RIBA-2 results and both ELISA ratio and alanine aminotransferase (ALT) levels was demonstrated: 20% of samples with normal ALT level and 10% of samples with low ELISA ratio were reactive when 91% of samples with ALT greater than 2N and 69% of samples with high ELISA ratio were reactive. The totality of the 57 samples with both ALT greater than 2N and high ELISA ratio were reactive and 93% of samples with normal ALT level and low ELISA ratio were nonreactive.