Amino acid substitutions in core and HBsAg regions of hepatitis B virus in patients with monoinfection and HBV/HIV-coinfection in the Republic of Guinea

Abstract

The aim of this study was to characterize the genetic variants of HBV currently circulating in the Republic of Guinea, based on the nucleotide sequences of the complete virus genome, and to analyze clinically significant mutations in the Core and HBsAg regions during HBV monoinfection and HBV/HIV coinfection.Materials and methods. The study material was represented by 2616 blood serum samples collected from residents of the Republic of Guinea. The subjects were examined for the presence of HBV markers with a qualitative detection of HBsAg, HBs IgG, and HBCore IgG. HBV complete genome nucleotide sequences were obtained for 298 samples including HIV/HBV coinfected patients. Amplification and subsequent sequencing of HBV were performed using nested PCR with pair’s overlapping primers jointly flanking the complete HBV genome (S, P, C, X genes).Results. HBV serological markers were detected in 80.77% samples, while HBsAg was detected in 16.01% of the examined group. HBV DNA we detected in 22.36%. The prevalence of HBsAg-negative HBV in patients with HIV RNA is 45.16%, which is significantly higher than 6.07% found in the group without HIV infection. Phylogenetic analysis of HBV in the examined samples showed that HBV genotype E (75.5%) predominates in the group compared to HBV genotype D1 (9.39%), D2 (4.02%), D3 (6.37%), and A2 (4.7%). In the tested group, the variability of amino acids among the HBV samples was higher in the PreCore/Core region than in the PreS1/PreS2/S region. SHB mutations were detected in 83,89%, Core mutations in 94.29%, PreCore amino acid substitutions in 16.77% of the patients, respectively.The results obtained in this work demonstrate a high prevalence of HBV in the region and indicate the need for further largescale studies of HBV mutations in order to improve strategies for disease control and prevention in the Republic of Guinea.