Immune response to GOR, a marker for non-A, non-B hepatitis and its correlation with hepatitis C virus infection.

Recently, identification and molecular cloning of a host cellular gene designated GOR from chimpanzees experimentally infected with non-A, non-B hepatitis (NANBH) agent was reported. It was further demonstrated that there is a close association between the immune response to an antigenic peptide of GOR (GOR2) and NANBH. In order to define the specificity of the immune response, in the present study we have identified an additional epitope in the GOR gene sequence, upstream from GOR2, and studied its correlation with the immune response to hepatitis C virus (HCV) in NANBH patients. An enzyme-linked immunoassay (EIA) was developed which utilizes synthetic peptides designated spGOR346 and spGOR2 as the serological target for the detection of anti-GOR antibodies in patient serum samples from various hepatic and non-hepatic disease categories. GOR peptides identified 80-90% of the NANBH samples that were positive for HCV C100-3 and about 70% of the NANBH samples that were positive by Abbott prototype second-generation HCV antibody assay. Among a normal donor population(s), only 2-3% of the samples were positive for antibodies to GOR sequences, whereas from the patient categories unrelated to viral hepatitis as well as various nonhepatic diseases, the immune response to both GOR peptides was closely associated with the presence of antibodies to HCV. The data indicate that antibodies to GOR is a marker associated with NANBH.