Objective: To establish the enzyme linking immunosorbent assay (ELISA) test with the specific monoclonal antibody (McAb) for detecting the hepatitis C virus (HCV) antigen so as to study the possibility of HCV antigen detection from plasma and serum samples.
Methods: Among the McAbs against HCV core and NS3 region, several kinds of combination models were analyzed to choose the optimal one. 348 samples from volunteer donors were tested by this test to calculate the cutoff value. 371 samples, among which 146 samples were positive to anti-HCV and 225 ones were negative to anti-HCV, were screened. The antigen positive samples were confirmed by HCV nested PCR.
Results: The model of detection test was constructed with the C39,C7-6 as capture McAb and C39,C7-57 as HRP Conjugated McAb. This test could detect the C7 antigen to 5 ng/ml, and its cutoff value was determined as the average value of negative control by adding 0.25. Eleven of 146 samples positive to anti-HCV and 16 of 225 ones negative to anti-HCV were positive to HCV antigen. Among these 27 antigen positive samples, there were 23 positive to HCV RNA by PCR detection.
Conclusions: With this HCV antigen detection test, some of samples positive to HCV antigen can be found from plasma positive to and negative to anti-HCV and be confirmed by PCR. It is shown that it is possible to detect HCV antigen directly from plasma samples and it is important for HCV basic research and for control of transmission of HCV.