Trial Results for ELISA Test Kits for HBsAg Subtype and Hepatitis B Virus Genotype Identification in Human Blood Plasma

Abstract

For personalized treatment of chronic HBV-infected patients, it is necessary to identify hepatitis B virus (HBV) surface antigen (HBsAg) subtypes and HBV genotypes circulating among infected individuals. To this end, a laboratory version of the test kit for HBsAg subtype and HBV genotype identification in human blood serum/plasma using enzyme-linked immunosorbent assay (ELISA) and a custom monoclonal antibody (MAb) panel has been developed. With this kit version, it appears possible to identify the main HBsAg subtypes (ayw2, ayw3, adw2, and adrq+) and HBV genotypes (A, C, and D) circulation in Russian Federation. The aim of the work was to test the laboratory-developed ELISA kits for HBsAg subtyping and HBV genotyping in human HBsAg-positive blood plasma samples. A total of 146 HBsAg-positive plasma samples were tested. For 108 samples with detectable viral DNA, the results of HBsAg subtyping and HBV genotyping using the suggested MAb panel were compared with the results of genomic DNA sequencing for HBV isolates. For 38 HBsAg-positive samples in which HBV DNA could not be detected, ELISA, using the highly specific MAb panel kindly provided by P. Swenson, PhD, was employed as a reference technique. The study demonstrated that for the group of HBsAg-positive samples with detectable HBV DNA, the coincidence between the results obtained using the suggested MAb panel and the results of HBV DNA genome sequence analysis was 85% for HBsAg subtyping and 98% for HBV genotyping. For the group of HBsAg-positive samples with undetectable HBV DNA, the coincidence between the two techniques (the one using the suggested MAb panel and one using Swenson’s MAb panel) was 95% in the case of HBsAg subtyping and 100% for HBV genotyping. The reported results allow recommending the suggested laboratory ELISA test kit for HBsAg subtype and HBV genotype identification in human blood plasma as an alternative or a complementary technique to genomic analysis in order to study HBV characteristics especially in those cases when HBV DNA isolation appears impossible.