[Second generation hepatitis-C virus test and polymerase chain reaction in anti-C 100 negative patients with chronic...

The aim of our study was to evaluate whether a negative HCV test of the first generation (HCV-ELISA 1) using the antigen C100-3 excludes chronic HCV infection, or whether patients exist who are negative for antibodies to C100-3 in spite of chronic hepatitis C. 27 patients with histologically proven chronic non-A, non-B hepatitis, all of whom were HCV-ELISA 1 negative, were tested by the HCV test systems of the second generation (Ortho-HCV-ELISA 2 and Chiron-HCV-RIBA 2) based on the distinct HCV antigens 5-1-1, C100-3, C33c and C22-3. To determine the presence of viremia, serum samples were also tested for HCV-RNA with "nested" PCR. 10 of 27 patients proved to be persistently negative when tested with the second generation assays. One patient showed low grade reactivity by HCV-ELISA 2, but non-reactivity by HCV-RIBA 2. In none of these 11 patients was HCV-RNA detected. 16 (60%) of 27 patients negative with HCV-ELISA 1 were positive with HCV-ELISA 2. HCV-RIBA 2 detected antibodies to the structural core antigen C22-3 in all of these 16 patients and antibodies to the non-structural antigen C33c in 14 of them, while antibodies to 5-1-1 or C100-3 were not found in any of these cases. 10 (63%) of the 16 HCV-ELISA 1 negative, but HCV-ELISA 2 and HCV-RIBA 2 positive patients were positive for HCV-RNA by "nested" PCR.(ABSTRACT TRUNCATED AT 250 WORDS)