TNF gene promoter region polymorphisms and association with young-onset rheumatoid arthritis

Abstract

Rheumatoid arthritis (RA) is an inflammatory autoimmune disease that shares a major global economic burden due to disabilities and mortality risk. It affects all age groups with a female predominance. Tumor Necrosis Factor (TNF) a proinflammatory cytokine is one of the key players in etiology of autoimmune diseases such as RA. TNF gene promoter polymorphisms predict disease susceptibility, severity and therapeutic response. Therefore, the current case-control study was designed to evaluate the possible association of TNF gene promoter polymorphisms (-238 and - 308) with susceptibility to young-onset RA. The study involves 102 individuals (50 young-onset RA patients, 52 healthy individuals). Genomic DNA was extracted using a standard phenol-chloroform method followed by PCR-RFLP for the screening of TNF gene promoter polymorphisms (-238 and -308). The study resulted in the association of TNF -238G/A polymorphism with susceptibility to young-onset RA in the homozygous form GG (Odds Ratio = 3.23, p-value= <0.05), though no significant difference was observed for -308G/A polymorphism among young-onset RA patients and controls. Thus concludes; TNF -238/G/A contributes to the risk of susceptibility to young-onset RA, conversely, TNF -308 G/A protects against the disease. Consequently, the study has demonstrated a possible relationship of studied TNF polymorphism with young-onset RA.