The significance of circulating antibody to hepatitis C virus (HCV) envelope glycoprotein 2 (E2)/nonstructural protein 1 (NS1) glycoprotein was studied in 83 patients with chronic HCV infection diagnosed by polymerase chain reaction (PCR). E2/NS1 antibody was quantitatively examined by a passive hemagglutination test using recombinant E2/NS1 glycoprotein encompassing amino acids 388 to 664 of the HCV-H strain. The results were correlated with clinical and virological features such as genotypes and viremic levels assessed by a competitive reverse-transcription PCR assay. E2/NS1 antibody was found in 73 patients (88%), and its occurrence was related to viremic levels. E2/NS1 antibody titers were low in asymptomatic HCV carriers with low levels of viral replication; 9 of 17 such patients tested positive for E2/NS1 antibody (53%), compared with 64 of 66 chronic hepatitis C patients (97%) (P < .01). A significant direct relationship was observed between viremic levels and E2/NS1 antibody titers (r = .52, P < .01). Of the 13 patients with low viremic levels of < 106 copies/mL, only 5 tested positive for E2/NS1 antibody (38%), whereas 68 of the 70 patients with viremic levels of > or = 106 copies/mL had it (97%) (P < .01). As for the relation to HCV genotypes, no difference was seen in E2/NS1 antibody titers among genotypes examined (1b, 2a, and 2b). These findings suggest that the E2/NS1 antibody tested exhibits no neutralizing activity in chronic HCV infection but may serve as a serological indicator of active virus replication.
If you can't find a tool you're looking for, please click the link at the top of the page to "Go to old article view". Alternatively, view our Knowledge Base articles for additional help. Your feedback is important to us, so please let us know if you have comments or ideas for improvement.