Clinical and Diagnostic Laboratory Immunology, 09 1994, 545-551, Vol 1, No. 5
Copyright © 1994 by the American Society for Microbiology. All rights reserved.

Evidence of subtype-specific antibodies to antigenic epitopes in the NS5 region of hepatitis C virus in the circulation of patients with chronic hepatitis C

JA Quiroga, J Martin, M Pernas, M Pardo, M Herrero, I Castillo, J Bartolome and V Carreno
Hepatology Unit, Fundacion Jimenez Diaz, Madrid, Spain.

The antigenicity of the NS5 region of type 1 hepatitis C virus (HCV) was investigated by epitope mapping of the region spanning amino acids 2530 to 2723 of the HCV polyprotein. Six antigenic regions were recognized by anti-HCV positive sera from individuals with chronic hepatitis C in a modified enzyme-linked immunosorbent assay with synthetic oligopeptides. Five of these regions demonstrated intra-type 1 sequence variations defining subtype 1a and 1b HCV sequences. The region between amino acids 2623 and 2634 allowed testing of subtype- specific anti-NS5 antibodies; serological reactivity to subtypes 1a and 1b was observed in 27 and 61%, respectively, of 150 cases with chronic hepatitis C. Simultaneous reactivity to subtypes 1a and 1b was found in 23% of the patients. Detection of subtype-specific anti-NS5 antibody correlated in more than 80% of the cases with the HCV genotype (subtypes 1a and 1b) analyzed by PCR amplification of the NS5 sequence. These data provide evidence of the existence of a subtype-specific anti- NS5 response in the circulation of patients with chronic hepatitis C.