Objective: Hepatocytes are susceptible to FAS-mediated apoptosis. The impact of polymorphisms in the FAS gene on histopathological features of HCV infection was therefore investigated.
Design/methods: Three single-nucleotide polymorphisms in the FAS promoter were assessed in 190 patients with chronic hepatitis C. Associations between FAS haplotypes and fibrosis stage and activity grade were tested by univariate and multivariate analyses.
Results: While there was no correlation between FAS promoter genotype and fibrosis stage, patients carrying the GCA haplotype (P=0.03, Fisher's exact test) and those homozygous for the GTG haplotype (P = 0.06) tended to have lower activity scores. Logistic regression showed that these associations were independent of patient age, sex and alcohol consumption. In a logistic regression model incorporating only male gender (odds ratio 2.1, 95% confidence interval 1.1-4.1 P = 0.04), the presence of the GCA haplotype (OR 0.31 95% CI 0.13-0.78 P = 0.01), and GTG homozygosity (OR 0.26 95% CI 0.08-0.83 P = 0.02), all three factors were independently correlated with activity grade. Furthermore, the GTG haplotype appeared to have lower promoter activity than the wild type GTA haplotype in a hepatocellular carcinoma cell line.
Conclusions: Genetic polymorphism in the FAS gene may account for some of the histopathological variability in chronic hepatitis C.