IL-23 is a pro-inflammatory cytokine belonging to the IL-12 cytokine family. IL-23 is essential for the differentiation of Th17 lymphocytes, a subtype of T lymphocyte implicated in chronic inflammatory/autoimmune mediated diseases. Experimental models of arthritis and clinical indications have highlighted an important role for Th17 lymphocytes in the pathogenesis of RA. However the role and mechanism of action of IL-23 in the pathogenesis of RA are still not fully understood.
This study was conducted to assess the level of IL-23 in patients with RA as well as the relationship between the IL-23 level and disease activity.
The study includes 77 patients with RA fulfilling the American College of Rheumatology (ACR) revised criteria for diagnosis of RA as well as 25 age and sex matched healthy subjects as controls. Patients were divided according to disease activity into four groups: DAS 28 score (˂ 2.6), 10 patients in remission, DAS 28 score between 2.6-3.2, 10 patients with low disease activity, DAS 28 score ranges between (3.2-5.1), 30 patients with moderate disease activity and DAS 28 score (˂ 5.1), 27 patients with High disease activity. Disease activity were determined by the 28-joint disease activity score (DAS 28). Anti-citrullinated protein antibodies (ACPA) was done. The levels of IL-23 were determined by enzyme-linked immunosorbent assay (ELISA).
Serum level of IL-23 was significantly elevated in RA patients (78.92±52.47) compared to control group (33.34±3.99) (P<0.001). However, no correlations were found between IL-23 and DAS 28 score, and other patients characteristics.
Our results imply that IL-23 may potentially play a role in the pathogenesis of RA and may be a useful biomarker for the diagnosis of this disease. Targeting the IL-23 cytokine may provide a new therapeutic approach in the treatment of RA.