Clinical significance of basal core promoter and precore mutations in chronic hepatitis B

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.

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.

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 (G1896A and G1899A). 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.

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.