Antibody response to recombinant HCV antigens and detection of HCV RNA in serum samples of blood donors positive for anti-HCV by 2nd generation HCV antibody screening test.

We studied antibody response against three different recombinant antigens (5-1-1/c100-3, c33c, c22-3) by RIBAII and detection of HCV RNA by RT-PCR in serum samples of blood donors positive for anti-HCV by 2nd generation HCV antibody screening test (PHA).In 52 serum samples showing PHA titer≥212, 37 samples (71%) were reactive to three different antigens (5-1-1/c100-3, c33c, c22-3), and other 15 samples (29%) were reactive to two different antigens (c33c, c22-3). Moreover, HCV RNA was detected in 51 samples (98%) by RT-PCR.On the other hand, in 52 serum samples showing PHA titer 25-11, only one samples (2%) was reactive to three different antigens (5-1-1/c100-3, c33c, c22-3) and other 7 samples (13%) were reactive to two antigens (c33c, c22-3). Twenty-five samples (48%) were reactive only to core antigen (c22-3). HCV RNA was detected in 5 samples (10%) out of these 52 samples.These results suggest that blood donors showing PHA titer≥212 are HCV carriers and the majority of blood donors showing PHA titer 25-11 may have past infection of HCV.