Association of TNF-α Promoter Polymorphisms and Some Inflammatory Cytokines with Susceptibility to Rheumatoid Arthritis in Saudi Population

Background: Tumor Necrosis Factor-α (TNF-α) is coded and regulated by TNF-α gene which is implicated in the predisposition of Rheumatoid Arthritis (RA). This study aims to detect TNF-α (G-308Α) promoter polymorphism and evaluate its association with susceptibility to Rheumatoid Arthritis. Methods: In the present study, 50 patients with RA and 50 healthy individual were included and evaluated for the C-reactive protein, rheumatoid factor, and TNF-α were evaluated by ELISA, Erythrocyte Sedimentation Rate (ESR) by Westergren method and for TNF-α -308 G > A polymorphism by polymerase chain reaction with amplification refractory mutation system (PCR-ARMS). Results: The CRP, RF, ESR and TNF-α were significantly elevated in RA patients relative to controls. The serum level TNF-α was also significantly elevated in female patients and in patients ≥ 50 years. Analysis of TNF-308 gene polymorphism revealed that GG genotypes were more common in RA than in the controls and that GG genotype may be a risk factor to RA. The G allele was more frequent in RA than in the control. Elevated TNF-α serum levels were significantly associated the GG genotype and functional disability in RA patients. Conclusion: TNF-α promoter 308 polymorphism GG genotype may be considered as a risk factor for RA and the TNF-α serum level was significantly related to the functional disability in the disease.