Relationship between precore/basal core promoter mutations of hepatitis B virus and therapeutic effect of peginterferon α-2b,and changes of mutations before and after treatment

AIM:To investigate the relationship between therapeutic effect of peginterferon α-2b (Peg-IFNα-2b) and precore (PC) region G1896A and basal core promoter (BCP) region A1762T/G1764A mutations of hepatitis B virus (HBV), and the changes of the mutations before and after treatment. METHODS:The patients with HBeAg-positive chronic hepatitis B (CHB) (n=69) were treated with Peg-IFNα-2b for 48 weeks and followed up for 24 weeks. The PC and BCP sequences at baseline and the 72th week were determined using polymerase chain reaction (PCR) and direct sequencing. Serum HBsAg, HBeAg, alanine aminotransferase (ALT) and HBV DNA was quantified in the samples taken at baseline (week 0), during the treatment period (weeks 4, 8, 12, 24, 36 and 48), and during follow-up (weeks 60 and 72). RESULTS:Within the total cohort, wild-type (WT) virus was detectable in only 14 patients (20.29%), and mutants were detected in 55 patients (79.71%). The serum HBeAg level in the patients with mutant virus was significantly lower than that in the patients with WT virus (P=0.024). The proportion of WT, PC mutant, BCP mutant and PC+BCP mutant was significantly changed at baseline and week 72 (P=0.004). No significant difference of HBeAg seroconversion and combined response between patients with WT virus or mutants (PC, BCP and PC+BCP) was observed. CONCLUSION:PC and BCP mutations have no effect on the response of HBeAg-positive CHB patients to Peg-IFNα-2b. The proportion of each mutation was significantly changed before and after treatment.