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.