Clinical Features of Chronic Hepatitis B in Treatment-naive Asian Patients With Positive HBeAg and Coexisting Precore and/or Basal Core Promoter Mutations

Background: Precore or/and basal core promoter (PC/BCP) mutations are frequently detected in hepatitis B e antigen (HBeAg)-negative patients, but little is known about their clinical significance in HBeAg-positive patients. Aim: To characterize and report the clinical features of treatment-naive chronic hepatitis B patients who are HBeAg positive and harbor PC and/or BCP mutations. Patients and Methods: Consecutive treatment-naive patients with chronic hepatitis B between 2004 and 2014 were enrolled. Clinical characteristics were compared based on the stratification of HBeAg status and the presence of PC/BCP mutations. In addition, subset analysis in HBeAg-positive cohort was performed to compare clinical features of patients with and without PC/BCP mutations Results: Of the 267 patients enrolled from 3 centers, 177 were HBeAg positive and 90 HBeAg negative. When compared with HBeAg-negative patients, HBeAg-positive patients were significantly younger in mean age (37.93 vs. 44.40; P<0.001), had higher levels of median ALT (51 vs. 30.5 U/mL; P<0.001), higher levels of mean HBV DNA (7.50±1.48 vs. 5.10±1.44 log 10 copies/mL; P<0.001), and lower frequency of detectable PC/BCP mutations (60.45% vs. 93.33%; P<0.001), but had significantly higher frequency of BCP when mutations were detected (37.85% vs. 22.22%; P=0.013). Among HBeAg-positive patients, when compared with patients with wild type, those with PC/BCP mutations were significantly older (30.63 vs. 42.71; P<0.001), had higher median ALT levels (29.5 vs. 73 U/mL; P<0.001), but there was no significant association with mean HBV DNA levels (7.96 vs. 7.20 log 10 copies/mL; P=0.865) or HBV genotype (P=1.000). In the multivariate analysis, only age and ALT were independently associated with PC/BCP mutations in HBeAg-positive patients, but there was no association with HBV genotype or DNA. Conclusions: PC/BCP mutants were frequent (up to 60%) in treatment-naive HBeAg-positive patients and were associated with distinct clinical characteristics when compared with patients with wild type or HBeAg negative. Future large studies are needed to substantiate the long-term clinical outcomes when PC/BCP mutations are detected in HBeAg-positive patients as it may impact the natural history or treatment response in such patients.