RESUMO
BACKGROUND: Hepatitis C virus (HCV) is a major cause of liver disease worldwide and in Egypt. The aim of this study was to detect HCV E1/E2 antigens using a novel mouse monoclonal antibody (mAb) designated (7G9) as a diagnostic and alternative approach for HCV detection. METHODS: The detection of HCV-E1/E2 antigens in 138 patients positive for HCV infection tested by RT-PCR and 25 healthy individuals negative for HCV as control group was done by an optimized in-house ELISA and DotELISA (based on the molecular mimicry of E2 to immunoglobulins). RESULTS: The mAb (7G9) was found to be IgM (heavy-chain)/kappa (light-chain) and characterization by western blot revealed two bands at 63 kDa for E2 and 31 kDa for E1. ELISA peptide mapping showed high reactivity with peptide derived from HCV E1 (a.a. 315 - 323) and low reactivity to peptides derived from HCV E2 (a.a. 517 - 531) and HCV E2 (a.a. 412 - 419). The mAb (7G9) showed no reactivity with HBV Ag, S. typhi or B. Abortus Ag proving high specificity. AUC for HCV-E1/E2 detection was 0.96 for all HCV patients with sensitivity 87% (119/137), specificity 88% (22/25) and efficiency 87%. The HCV-E1/E2 antigens detection by Dot-ELISA showed 76.8% sensitivity, 88% specificity and the efficiency of the assay was 78.5%. Furthermore, no correlation was found between serum HCV viral load and HCV E1/E2 antigens detection. CONCLUSIONS: The ELISA and Dot-ELISA based on the monoclonal antibody (7G9) are reliable, rapid, easy and economic diagnostic assays for HCV infection.