Objectives: Rheumatoid arthritis (RA) is a chronic inflammatory disease in which tumour necrosis factor-alpha (TNF-alpha) plays an important role. There are, however, controversial reports that TNF-alpha promoter polymorphism may be an independent marker of susceptibility and severity of RA. The aim of the present study was to examine the TNF-alpha -308 promoter polymorphism in patients with RA.
Methods: We examined 91 patients with RA diagnosed according to the criteria of the American College of Rheumatology. Polymerase chain reaction (PCR) amplification was used for analysis of the polymorphism at position -308 in promoter of TNF-alpha gene.
Results: Distribution of TNF-alpha genotypes in RA patients did not differ from that in control subjects. Moreover, there was no association between TNF-alpha genotypes and age at disease diagnosis, disease activity in global physician's assessment, and joint and extra-articular involvement. There was also no correlation between TNF-alpha polymorphism and disease activity measures, including erythrocyte sedimentation rate (ESR), CRP, number of swollen and tender joints, and morning stiffness duration.
Conclusions: We suggest that TNF-alpha -308 promoter polymorphism is not a genetic risk factor for RA susceptibility and severity.