Genetic Variation in TNF-α, its Relation with Inflammatory Biomarkers and Susceptibility to Rheumatoid Arthritis

Abstract

Background: Tumor necrosis Factor-α (TNF-α) is encoded and controlled by TNF-α gene, which is involved in rheumatoid arthritis (RA) susceptibility. This research aimed to identify genetic variations of TNF-α (G308A) and to establish its association with inflammatory markers in Rheumatoid Arthritis predisposition. Methods: In the present study, fifty RA patients and fifty volunteers were involved and evaluated for the C-reactive protein, rheumatoid factor, and TNF-α were estimated by ELISA, Erythrocyte Sedimentation Rate (ESR) by Wintergreen 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 prevalent in RA patients than in the healthy individuals and that GG genotype may be a potential factor to RA. The G allele was more common 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 308polymorphism 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.