System biology analysis of Rheumatoid Arthritis and evaluation of the IL-6 and IL-6R genes expression in treated patients

Rheumatoid arthritis(RA) is a complex and chronic disease of joint inflammation. Environmental factors that are important in genetically predisposed people are involved in the occurrence of the disease and its progress. This disease has a lot to related to genetics, including human class 2 antigens. In various studies, this relation is about 60%. This relationship is more positive in people with Anti-citrullinated protein antibodies (ACPA) than negative ones. The aim of this study is to investigate the relationship between cytokines and soluble proteins in the body of a patient with Rheumatoid arthritis before symptoms appear.

In this research, analysis with Enrichr, WebGestalt, and GeneMANIA was used to find genes related to the disease. In order to check the amount of cytokines predicted, ELISA and Real time RT-PCR methods were applied.

By examining the System Biology methods, the candidate genes included IL-6R, IL-6 and IL-23A. The samples were taken from 46 RA patients referred to the rheumatology department of the Babol hospital, and a significant decrease (Pv=0.1255) of IL-6 was observed in patients undergoing treatment and a significant increase (Pv=0.4414) in the amount of this cytokine receptor in the serum compared to healthy individuals. While the expression of IL6 and IL6R genes increased in the patient group compared to the healthy group.

Cytokine IL-6 as an inflammatory cytokine in treated patients decreased in serum and showed a significant increase in RNA level.