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.
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.
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.
We suggest that TNF-alpha -308 promoter polymorphism is not a genetic risk factor for RA susceptibility and severity.