Association of IL-6 genotypes with their serum levels among Iraqi patients with rheumatoid arthritis

Abstract

Rheumatoid arthritis (RA) is a complex autoimmune system disease and significant impact on
the health of the population in our world. Numerous studies confirmed that genetic factors play a
crucial role in the pathogenesis of RA. Interleukin-6 (IL-6) is a common pro-inflammatory
cytokine that has several roles in a variety of pathophysiologic systems, most notably in the
development of rheumatoid arthritis (RA). This study aims to investigate the association of
polymorphism of the “IL-6 174 G/C rs(1800795) gene” to their serum levels among Iraqi
patients. A total of 60 participants (40 confirmed rheumatoid arthritis patients and 20 controls)
were selected using a convenient sampling method. “Genetic polymorphism of IL-6 174 G/C
rs(1800795)” was carried out using RFLP-PCR. Serum levels of IL-6 were performed using by
enzyme-linked immunosorbent assay technique (ELISA) using a Human- IL-6 kit. Based on the
polymorphism of IL-6 174 G/C rs(1800795), serum levels of IL-6 were higher among
rheumatoid arthritis patients with CC and GC genotypes than that with GG genotypes (CC,
137.5336±35, GC 135.0622±70.88476and GG 65.5587±1.77873, P < 0.05. Furthermore, patients
with GG genotype had the lowest IL-6 level with an insignificant difference compared to
controls1. 65.5587±1.77873vs. 59.8203±1.30673,P> 0.05.