Published online Jun 15, 2004. doi: 10.3748/wjg.v10.i12.1810
Revised: December 9, 2003
Accepted: December 16, 2003
Published online: June 15, 2004
AIM: To clarify whether -238G/A polymorphism of tumor necrosis factor-α (TNF-α) gene promoter region was associated with outcomes of hepatitis B virus (HBV) infection in Han population of northern China, and to analyze the gene-environment interaction between -238G/A polymorphism and cigarette smoking or alcohol consumption.
METHODS: A case-control study was conducted to analyze the association of TNF-α gene promoter polymorphism with HBV infection outcomes. A total of 207 patients with chronic hepatitis B (HB) and 148 cases of self-limited HBV infection from Ditan Hospital and Shunyi District Hospital in Beijing, respectively were recruited. History of smoking and alcohol drinking was inquired by a questionnaire. The -238G/A polymorphism of TNF-α gene promoter was genotyped by polymerase chain reaction-restricted fragment length polymorphism (PCR-RFLP).
RESULTS: The frequencies of GG and GA genotypes were 98.07% and 1.93% in chronic HB patients and 93.24% and 6.76% in self-limited HBV infection individuals, respectively (χ2 = 5.30, P = 0.02). The frequency of G allele was significantly higher in patients with chronic HB that in individuals with self-limited HBV infection (99.03% vs 96.62%, χ2 = 5.20, P = 0.02). Only modestly increased risk of onset of chronic HB was found in smokers (OR = 1.40, 95% CI: 0.87-2.28, P = 0.14) and drinkers (OR = 1.26, 95% CI: 0.78-2.05, P = 0.32). There was a positive interaction between genotype GG and cigarette smoking with an interaction index (II) of 2.95, or alcohol consumption with an II of 1.64.
CONCLUSION: The -238G/A polymorphism of TNF-α gene promoter region is independently associated with different outcomes of HBV infection.