Tumor necrosis factor-alpha gene promoter polymorphism in Iranian patients with chronic hepatitis B

Clearance of hepatitis B virus (HBV) infection requires a good host immune response. Cytokines like tumor necrosis factor-alpha (TNF- alpha) may play a role in such immune response. Genetic changes in TNF-a gene promoter region are known to influence TNF- alpha expression. We therefore studied the role of one such mutation in chronic HBV infection. Presence of -308 G/A polymorphism in the promoter region of TNF- alpha gene was looked for in 100 patients with chronic HBV infection, 91 subjects with spontaneously recovered HBV infection and 89 healthy controls, using a PCR-RFLP method. Variant alleles (A/A or A/G) were found in 22 of 100 (22%) patients with chronic HBV infection, 21 of 91 (23%) subjects with spontaneous HBV clearance and 14 of 89 (15.7%) control subjects (p=ns for inter-group comparisons). TNF- alpha promoter polymorphism -308A is common in Iranian population, but has no association with development of chronic HBV infection.