CLINICAL-SIGNIFICANCE OF THE ANTIBODY TO THE PUTATIVE CORE PROTEIN OFHEPATITIS-C VIRUS IN PATIENTS WITH CHRONIC LIVER-DISEASE

We evaluated the clinical significance of the antibody to hepatitis C core protein (anti-p22) analysing 147 sera from 99 patients; 45 of the m had post-transfusion non A non B (NANB) hepatitis, 28 cryptogenic no n A non B hepatitis, 12 chronic hepatitis B, 7 chronic hepatitis D, 6 other forms of liver disease (4 primary biliary cirrhosis, 2 autoimmun e hepatitis) and 1 rheumatoid arthritis. All sera were tested by comme rcial 1st and 2nd-generation ELISAs and anti-p22 single antibody ELISA . We found a highly significant correspondence between anti-p22 and co mmercial assays (p = 0.0001). HCV-RNA was detected by reverse transcri ptase polymerase chain reaction (RT-PCR) in sera showing positive or n egative concordant results and in all sera (24) that showed discordant results by anti-p22 and comercial ELISAs. HCV-RNA was found in 14 of 17 (82%) anti-p22 positive sera that were negative by commercial ELISA s, in 1 of 7 (14.3%) anti-p22 negative sera that were positive by comm ercial ELISAs (p=0.001) and in all control sera from patients with pos itive concordant results. It was undetectable in 7 sera from patients with autoimmune diseases (negative by all ELISAs). We studied follow-u p sera from 16 patients treated with interferon: 8 long-term responder s (with persistently normal ALT levels for at least 24 months after di scontinuation of therapy and histological remission) and 8 non-respond ers. Sera were also tested by a 4-antigen recombinant immunoblotting a ssay (RIBA II). A relation was observed between the optical density of anti-p22 ELISA and anti-C22 as detected by RIBA and between the persi stence of high levels of anti-p22 and HCV-RNA (p=0.001). These results suggest that anti-p22 ELISA is comparable for specificity and sensibi lity with commercially available assays. It appears to be a convenient and easy to perform test for diagnosis and monitoring of HCV infectio n.