Rheumatoid arthritis and genetic variations in cytokine genes: a population-based study in Kashmir Valley.

Objective: The aim of our study was to determine the genetic associations between polymorphisms of the IL1β gene (-511C/T and +3953C/T) and IL6 gene (-174G/C) with disease susceptibility and severity in patients with rheumatoid arthritis (RA) in ethnic Kashmiri population.

Methods: Allele and genotype frequencies of IL1β -511 C/T, IL1β +3953 C/T and IL6 -174 G/C polymorphisms were compared between 150 RA patients and 200 healthy controls by using PCR-RFLP method.

Results: We did not find any significant association between IL1b +3953 C/T and IL6 -174 G/C polymorphism and Rheumatoid Arthritis risk (p>0.05), but IL1β +3953 CT genotype was associated significantly with increased SJC and ESR and IL6 -174 GG genotype was associated significantly with increased ESR. However IL1b -511C/T polymorphism was significantly associated with rheumatoid arthritis risk and the carriers of IL1β -511 'C' allele (CC and TC genotypes) appeared to have lower risk for RA development.

Conclusions: Our findings suggest that the IL1b -511 'C' allele has a protective role from disease development. Furthermore our results suggest a possible role of IL1b +3953 CT and IL6 -174 GG genotypes as disease activity markers of rheumatoid arthritis.