Ultra-Deep Pyrosequencing of Precore/Core Promoter Mutations in Patients with Genotype D Chronic Hepatitis B

Abstract

AIM: The clinical course is different in patients who are HBeAg-negative or positive during the natural course of chronic hepatitis B virus infection. In this study, we aimed to investigate the prevalence of precore and basal core-promoter mutations in chronic hepatitis B patients using ultra-deep pyrosequencing METHODS: Sixteen patients with treatment naive chronic hepatitis B (12 HBeAg-positive) were studied (8 male, mean age 29.2±12.8 years). Pretreatment serum HBV-DNA concentrations were determined using a Bayer bDNA Analyzer system 340 and UDPS was performed using the GS FLX platform. RESULTS: All patients were genotype D1. A1762T-G1764A core-promoter double mutations were detected in 2(17%) HBeAg-positive patients, but not detected in any HBeAg-negative patients. T1842C mutation was observed in 5 HBeAg-positive patients, but not observed in HBeAg-negative patients. This mutation was accompanied with G1816A and C1845T mutations in each patient. Although G1862A mutation was common in HBeAg-negative patients in our study, this mutation was positive in 1 HBeAg-negative and 6 HBeAg-positive patients. The G1896A precore stop codon mutation rate was 33% in HBeAg-positive and 75% in HBeAg-negative patients. The total detectable precore and BCP mutation rates were 92%, and 67%, respectively. CONCLUSION: Precore/core promoter mutations were frequent in patients infected with genotype D HBeAg-positive HBV. These findings show that HBeAg can be positive even in the presence of precore mutations.