Interleukin-17A-197G/A Promoter Polymorphism in Patients with Rheumatoid Arthritis and Its Relation with Disease Activity and Severity

Abstract

Background: The Th17 master cytokine, IL-17A, has been discovered to be the most effective in the development of autoimmune disorders, suggesting that it is the major mediator. The goal of this study is to see how the IL17A polymorphism in the -197 G/A promoter region affects IL17 levels and illness severity.

Objective: The goal of this study was to see how the IL17A polymorphism in the -197 G/A promoter region affected blood IL17 levels, illness severity, and treatment responsiveness in rheumatoid arthritis patients vs controls.

Methodology: At Aswan University Hospital's Clinical Rheumatology department, a case-control research was done on 35 patients with RA. 30 healthy volunteers, age and sex matched to the sick group, were examined for RF, anti-CCP antibodies, CRP, ESR, and serum IL-17. RFLP was performed on PCR products generated using IL-17A 197 G/A primers.

Results: Anti-CCP antibodies were positive in 25 (71.43 percent) and RF were positive in 33 (94.29 percent). CRP was high in 31 of them (88.57 percent). G/G Genotypes 5 (14.29 percent), G/A 18 (51.43 percent), and A/A 12 (34.29 percent). In the group with more active RA (DAS28 >5.1), the amount of IL-17 in the blood was significantly higher than in the group with less active RA (DAS28 ≤5.1). RA patients with more active illness (DAS 28>5.1) had a higher percentage (60%) of wild type G/G genotype than those with less active disease (DAS 28 5.1), where wild type G/G genotype is less common (40 percent).

Conclusions: This study's findings suggest that the IL17A gene polymorphism is associated to RA clinical features rather than disease predisposition.