Clinical Significance of Basal Core Promoter and Precore Mutations in Chronic Hepatitis B

Background/Aims: The mutations in the basal core promoter and precore region of hepatitis B virus genome in hepatitis B e antigen-positive and -negative chronic hepatitis B patients have been described. The reports about their prevalence and clinical significance in the Mediterranean region where D is the predominant genotype, are very limited. Methodology: The serum samples were collected from 44 naive chronic hepatitis B patients. For detection of the mutations basal core promoter and precore regions of HBV genome were amplified and sequenced. Results: All samples were determined as genotype D. Before initiation of treatment basal core promoter mutations were found as 55% (11/20) and 46% (11/24) in HBeAg-positive and -negative patients, respectively (p>0.5). HBeAg-negative samples were associated with precore mutations (G1896 A and G1899 A ). Three of 20 (15%) patients of HBeAg-positive and seven of 24 (29%) of HBeAg-negative populations showed sustained response to therapy at the 24th month of initiation. Conclusions: The presence of precore stop codon mutant in those with sustained response was 89%, overall at the end of therapy. At initiation of therapy basal core promoter mutations were more common in non-responders than responders (65% vs. 20%; p<0.001). While 23% of cases totally showing sustained response, absence of mutations in the basal core promoter region of hepatitis B virus genotype D may be related to sustained response in patients with chronic hepatitis B.