Understanding the correlation of IL-6 with circRNA-DLGAP4 in the pathogenesis and diagnosis of rheumatoid arthritis

Rheumatoid arthritis (RA) as a systemic autoimmune disease is often misdiagnosed in its early stages due to vague symptoms, delaying treatment and increasing the likelihood of severe complications including cardiovascular mortality. The main aim of this work is to evaluate the serum levels of interleukin 6 (IL-6) and circular RNA DLGAP4 (circRNA-DLGAP4) in RA patients and healthy controls, also analyzing the correlations between all biomarkers to indicate whether those can be used as predictors for early diagnoses of RA. One hundred subjects were included, they were divided into two equal groups, 50-healthy matched individuals and 50 RA patients. For all participants, a venous blood sample for serum isolation was taken and analyzed for the serum level of IL-6 and circRNA-DLGAP4 as well as laboratory tests. For all patients, full clinical investigations have been performed as well as Disease Activity Score (DAS28) and modified Larsen radiological scoring have been calculated. Results revealed that there was a significant up-regulation of the concentration level of IL-6 (p = 0.0001) and circRNA-DLGAP4 expression (p = 0.0001) in the RA group as compared to healthy controls. Moreover, altered expression of circRNA-DLGAP4 showed a slight significant difference between patients with positive deformities with p = 0.05. Serum levels of both IL-6 and circRNA-DLGAP4 increased with the severity of RA. Various correlations were detected of both IL-6 and circRNA-DLGAP4 with the associated RA parameters. It can be concluded that IL-6 and circRNA-DLGAP4 could have a potential role in RA pathogenesis and could act as possible biomarkers of RA for further studies to be applied for RA diagnostic purposes.