Genotypes, immune escape and drug resistant mutations of Hepatitis B virus among isolates of Afghanistan

BACKGROUND AND OBJECTIVESHepatitis B virus (HBV) infection remains a significant public health concern worldwide, leading to severe liver diseases such as chronic hepatitis, hepatocellular carcinoma, and liver cirrhosis. It continues to be prevalent among high-risk populations and non-immunized individuals in regions with high endemicity. Afghanistan is no exception, but there is limited information about the molecular aspects of HBV circulating in the country. This study aimed to investigate the genotyping patterns, mutations, and other molecular characteristics among HBV isolates in Afghanistan.MATERIALS AND METHODSThis cross-sectional study included patients who tested positive for HBsAg. Approximately ۵ ml of venous blood was collected, and the separated serum was serologically tested for anti-HBc, HBsAg, anti-HBs, and HBeAg. Molecular examinations, including DNA extraction and various PCR assays, were performed to determine HBV genotypes. Additionally, the full S gene was amplified, sequenced, and analyzed phylogenetically to investigate mutations and genotyping of HBV .RESULTS AND DISCUSSIONOut of ۱۲۰ cases, all were positive for HBsAg. The mean age of the patients was ۳۹.۲ ± ۵.۱ years, ranging from ۱۸ to ۷۵ years, and ۳۸% were male. Phylogenetic analysis revealed that all isolates belonged to the HBV genotype D. Sub-genotype distribution indicated a predominance of D۱, with ۳.۹% classified as D۲. The most prevalent mutations observed were N۲۰۲S and T۲۰۸I. Furthermore, immune escape mutations, including I۱۱۰L (۱۶%), P۱۲۰S (۸.۷%), and S۱۴۳L (۲۵.۸%), were found in polymorphic sites of HBsAg. Within the YMDD motif, M۲۰۴V and D۲۰۵T mutations were present in ۵.۳% of cases .CONCLUSIONThe genotyping pattern of HBV in Afghanistan is consistent with neighboring countries and regions. Further investigation is required to trace clades and conduct evolutionary analysis to determine the main routes of transmission and circulation. The incidence of viral escape and drug-resistant mutations was noteworthy, necessitating additional research .

کلیدواژه ها:

Hepatitis B virus ، HBV ، HBsAg-positive ، Phylogenetic analysis ، mutation ، Afghanistan