interleukin-33 and interleukin-18 serum levels in patients with rheumatoid arthritis and osteoporosis

Background and Aim: Limited studies have been focused on the role of IL-33 and IL-18 in Rheumatoid arthritis (RA).This study was done to measure the levels of IL-18 and IL-33 in the serum of patients with RA, before treatment, three month after treatment and compare to patients with osteoporosis as well as healthy controls. Materials and Methods: Sera were obtained from 20 patients with RA before treatment, 15 patients with osteoporosis and 30 healthy controls that have been matched to patients group. IL-33 and IL-18 levels were measured using ELISA assay. Results: Serum levels of IL-33 were significantly higher in patients with RA before treatment 5.47± 0.142 (pg/ml) versus three months after treatment 4.34±0.072, P=0.001, and control subjects 4.53±.076 (pg/ml), P=0.000. There were significant differences between IL-33 serum levels in patients with RA before treatment compare to osteoporosis subjects before treatment (5.47± 0.142 versus 3.65±0.08, P=0.000). The serum IL-18 levels of the RA patients before treatment 482.12±67.38 (pg/ml) were significantly higher than the IL-18 level three months after treatment 302.67±55.33 (pg/ml) P=0.004, the control group 216.19±47.56 (pg/ml) P= 0.004 and patients with OP 316.79±53.72, p= 0.001. Conclusion: Our results showed that IL-33 and IL-18 are highly active in RA and these cytokines might be closely involved in the pathologic mechanisms of the disease