HBV Surface Ag mutations in chronic carriers are rare in Baloochstan provinces of Iran: a community with a low rate of HBV-related cirrhosis and HCC

Background and Aims: The aim of this study was to determine the correlation between the hepatitis B virus surface Ag (HBsAg) genotypes and variations in the clinical/serological pictures among HBsAg positive chronic patients from South Khorasan province of Iran. Methods: Twenty-five patients were enrolled in this study. The HBs Ag gene was amplified and was directly sequenced. Genotypes and nucleotide/amino acid substitutions were characterized comparing with sequences obtained from the database. Results: All strains belonged to genotype D, subgenotype D1 and subtype ayw2. Eight samples (group I) contained at least one mutation at the single amino acid level. Five out of 8 samples showed ALT levels above the normal range of which only one sample was anti-HBe positive. Group II (17 samples) did not contain any mutation, 4 were anti-HBe positive and 9 had increased ALT levels. In both groups, in anti-HBe positive patients who showed high levels of ALT, only one sample had amino acid mutations. Conversely, 7 of 20 samples with HBeAg positivity had mutations. In both groups, from a total of 18 amino acid mutations, 5 (27.5%) and 13 (72.5%) occurred in anti-HBe and HBeAg positive groups respectively. In general, there was no correlation between the occurrence of mutations and HBeAg status/ALT levels of the patients. Conclusion: The relatively small number of nucleotide/amino acid mutations might belong to either the initial phase (tolerant phase) of chronicity in our patients, regardless of being anti-HBe positive; or that even in anti-HBe positive phase in Iranian genotype D-infected patients, a somehow tolerant pattern due to the host genetic factors may be responsible.