Aim: Study heterogeneity ofhepatitis B virus in adult patients with chronic hepatitis B and determination of diagnostic potential of modern test systems with the detection of HBsAg with amino acid substitutions in the main hydrophilic region (MHR).
Materials and methods: In 27 hepatitis B virus samples isolated from patients with chronic hepatitis B virus infection living in Vladimir, nucleotide sequence ofgenome region corresponding to preS1/preS2/S genes was determined.
Results: In all of the 27 isolates genotype D virus presented by 3 subgenotypes D1, D2, D3 was detected in 18%, 26% and 56% respectively. Based on the distribution of nucleotide substitutions in the compared functional regions of hepatitis B virus (virus entry into the cell coding site (2875 - 2991 n.b.), pre-S2/S promoter region (2994 - 3171 n.b.), 5'-end pre-S2 and S-genes sequences (3172 - 154 n.b. and 155-455 n.b.), MHR (455 - 635 n.b.) and 3'-end S-gene sequence (636 - 835 n.b.), substitutions are mostly concentrated in the promoter region of the S2/S-genes (30.8%). HBsAg serotypes were determined in 24 of 27 cases by using the predicted amino acid sequence, and in 17 cases HBsAg belonged to ayw2 (71%) serotype and in 7 cases - to ayw3 serotype (29%). Amino acid substitutions G145A, M133I, S132T localized in the main hydrophilic region and P217L, S207N, V184A localized in the C-end of the protein C that are connected with diagnostic and vaccine escape were identified in 5 isolates.
Conclusion: Diagnostic potential of test systems with the detection of HBsAg with known amino acid sequence of the MHR region were studied. Approximately equal potential of 6 test systems to detect HBsAg with amino acid substitutions G145A, M133I and S132T localized in the MHR region were shown.