Association between tumour necrosis factor gene polymorphisms and the clinical types of patients with chronic hepatitis B virus infection

ABSTRACT A PCR restriction fragment length polymorphism assay was used to analyse single-nucleotide polymorphisms in the tumour necrosis factor (TNF)-α and TNF-β genes of 56 patients with chronic severe hepatitis B virus (HBV) infection, 71 patients who either had chronic mild HBV infection or who were asymptomatic carriers, and 90 healthy controls. The serum TNF-α concentrations in patients with chronic severe HBV infection were compared to those of 30 healthy controls by radioimmunoassay. The frequencies of the TNF1/2 genotype and the TNF2 allele were greater in patients with chronic severe HBV infection than in healthy controls (25% vs. 11.1%, p 0.015; 12.5% vs. 5.6%, p 0.036, respectively) and patients with chronic mild HBV infection and asymptomatic carriers (25% vs. 8.8%, p 0.011; 12.5% vs. 4.2%, p 0.015, respectively). Heterozygotes carrying the TNF2 allele had higher levels of serum TNFα than homozygotes for the wild-type allele among all patients with chronic severe HBV infection (p