Significance of recombinant proteins encoded by different fragments of hepatitis C virus (HCV) gene for detection of anti-HCV antibodies

Objective To study the immunoreactivity of the recombinant proteins encoded by different fragments of HCV gene and explore the significance of the proteins in detection for anti-HCV antibodies.Methods Four HCV recombinant proteins encoded by C,NS3,NS4 and NS5 region respectively were applied for ELISA detection of anti-HCV antibodies.Ninety serum samples which were known to be anti-HCV-positive were tested with each of the four antigens or the mixed proteins.One hundred specimens collected from healthy undergraduates and 39 samples from an anti-HCV-negative reference panel were tested with the mixed antigens.Results Seventy-five out of the 90 known anti-HCV-positive specimens were immunoreactive to one or more of the 4 HCV recombinant antigens.The positive rates of anti-C,anti-NS3,anti-NS4 and anti-NS5 were 70.0%,61.1%,52.2% and 44.4%,respectively.Eight serum samples only reacted with C antigen.One samples only reacted with NS3 antigen.Two only reacted with NS4 antigen.One only reacted with NS5 antigen.However,all the 75 specimens (83.3%) were immunoreactive to the mixed antigens.All the specimens obtained from undergraduates and the anti-HCV-negative panel did not show any reactivity to the mixed antigens.Conclusion There is different immunoreactivity of the HCV recombinant antigens encoded by different gene fragments.The mixture of all the antigens derived from HCV different regions should be applied in further HCV diagnostic test to detect anti-HCV antibodies.