Tumor necrosis factor promoter polymorphisms in patients with rheumatoid arthritis in Taiwan

Objective. To investigate the association of tumor necrosis factor (TNF) promoter polymorphisms with rheumatoid arthritis (RA) in Taiwan. Methods. TNF promoter polymorphisms at positions -238, -244, -308 -376, -857, and -863 were determined in 97 patients with RA and 97 healthy controls using the PCR-RFLP method. Results. The phenotypic frequency of TNF-308A was significantly lower in patients with RA than in healthy controls. This finding can only be found in HLA-DR4 negative patients, not in DR4 positive RA patients and controls. The TNF promoter polymorphisms at positions -238, -244, -308, -376, -857, and -863 were not related to the clinical manifestations of RA patients. Conclusion. TNF-308A itself or a neighboring gene may be a protective factor for the development of RA in the HLA-DR4 negative population in Taiwan. TNF promoter polymorphisms were not associated with the clinical manifestations of patients with RA in Taiwan.