Lack of effect of tumor necrosis factor-alpha-308 G/A polymorphism on severity of liver fibrosis in Tunisian hepatitis C virus (HCV)-infected patients

International audienceObjectives. - Tumor necrosis factor alpha (INF-alpha) plays a key role in the immune response. An elevated plasma level of INF-alpha was repeatedly observed in patients with active liver injury or cirrhosis regardless of the aetiology. The G/A transition at position -308 in the promoter region have been shown to influence TNF-alpha expression. In this study, we aimed to evaluate the impact of TNF-alpha -308 G/A functional polymorphism on fibrosis severity in Tunisian Hepatitis C Virus (HCV)-infected patients. Methods. - TNF-alpha -308 G/A polymorphism was evaluated by polymerase chain reaction (PCR) amplification followed by Restriction Fragment Length Polymorphism (RFLP) method in 53 chronic hepatitis C patients Single-nucleotide polymorphism (SNP) frequencies were compared with regard to liver fibrosis severity as assessed by the METAVIR scoring system (F1-F2; n=22 versus F3-F4; n=31). Results. - The genotype distribution of the INF-alpha -308 G/A polymorphism among the HCV-infected patients was as follows : GG : 67.9%, GA: 32.1%, AA: 0%. With regard to fibrosis score, no significant differences in TNF-alpha genotype distribution were observed between F1-F2 and F3-F4 patients (p=0.15) Conclusion. - No significant association between TNF-alpha -308 polymorphism and and the severity of liver fibrosis was found in our Tunisian cohort

Hepatitis B genotypes, precore and core promoter mutants circulating in Tunisia

International audienceHepatitis B virus (HBV) is characterized by genetic heterogeneity, including genotypes and mutations. Eight genotypes (A-H) have been identified throughout the world with a characteristic geographical distribution. Previous studies also suggest that the viral genotypes may correlate with differences in clinical features of the infection. Two types of mutations were particularly described, precore and basal promoter mutations; they may play an important role in the clinical outcome of HBV infection. The aim of this study was to investigate the prevalence of HBV genotypes and HBV variants in Tunisia, and their eventual association with severity of liver disease. Using a molecular method, HBV genotypes, precore and basal core promoter mutations were determined in 56 asymptomatic carriers and in 82 patients with histologically verified chronic liver disease and hepatocellular carcinoma (HCC). Three genotypes (D, A, and E) were detected; the prevalence was 80%, 8%, and 9%, respectively. No significant difference was observed for genotype D with clinical status. HBV mutants were detected in 93% of cases, precore mutants were the most prevalent. Basal core promoter mutants were observed in 61% of cases, they were frequently characterized by a double mutation in 1762 and 1764. Co-infection by these two types of mutants was detected in 50% of cases. Genotype D was the most prevalent HBV genotype in Tunisia. High circulation of precore and basal core promoter mutants are common in chronic hepatitis B infection in Tunisia