Hepatitis B virus genotypes and precore/core-promoter mutations in Tunisian patients with chronic hepatitis B virus infection

Objective: The aim of this study was to determine the frequency of genotype and precore/core-promoter mutations in chronic hepatitis B virus (HBV) infected individuals in Tunisia. Methods: We studied 164 Tunisian patients (38 HBeAg-positive and 126 HBeAg-negative) with chronic HBV infection. Genotypes and precore/core-promoter mutations were studied using Inno-LiPA and Multiplex-PCR and PCR-RFLP methodology. Results: Alanine aminotransferase (ALT) levels were higher in HBeAg-positive compared with HBeAg-negative patients (p < 0.05). Patients with HBeAg-positive chronic hepatitis B were younger than HBeAg-negative chronic hepatitis B patients. The 164 genotypes were distributed as follows: 1 genotype A (0.6%), 1 genotype B (0.6%), 3 genotype C (1.82%), 139 genotype D (84.75%), and 20 mixed genotypes (12.2%). In the precore region (41.5%) of the patients had exclusively PC mutant and (50.9%) had a mixture of wild-type and variant sequences. PC variant was more commonly found in HBeAg-negative patients than in HBeAg-positive patients (94.5% vs. 87.8%), respectively. The mutations in the core promoter were more common in HBeAg-negative patients (65.4%) than in HbeAg-positive patients (18.2%). These results indicate that genotype D is predominant in Tunisia. Precore mutation occurred invariably among HBeAg-positive and HBeAg-negative patients, whereas core-promoter mutations were more frequently found in HBeAg-negative patients. Conclusion: Analysis of these mutants may prove useful for clinical evaluation and choice of therapy. (C) 2006 The British Infection Society. Published by Elsevier Ltd. All rights reserved.