Serum IL17 and IL6 levels in a Sample of Iraqi Patients with Rheumatoid Arthritis: A Case Control Study

Abstract

Objectives: To determine serum IL17 and IL6 levels in a sample of Iraqi patients with rheumatoid arthritis (RA) and to evaluate the correlation between them if present.

Methods: A case control single center study was conducted for 11 months. A total of 50 patients with RA diagnosed according to the 1987 American College of Rheumatology (ACR) and 30 individuals matched in age and sex as control group were included. Serum IL17 and IL6 levels were measured in both groups by enzyme-linked immunosorbent assay (ELISA). The cut off value was assessed by receiver operating characteristics (ROC) test and correlation by spearman's Rho linear correlation coefficient.

Results: Frequency of females was more than males in patients and controls (88% and 76.7% respectively).Ages of patients range between 20-70 years with a median 43.76 years while in controls, ages range between 20-60 years with a median 37.67 years.Serum IL17 concentration was significantly higher in patients compared to controls (median 154.4 pg/ml versus 111.1 pg/ml respectively, p=0.02). Also serum IL6 concentration was higher and highly significant in patients compared to controls (median 150 versus 49 pg/ml respectively, p=0.001). There was a direct strong highly statistical significant correlation between serum IL17 and serum IL6 concentration      (r=0.771, p<0.001).The optimum cut off value for IL17 was ? 71.8 pg/ml and IL6 concentration?8.1pg/ml.

Conclusions: serum IL17 and IL6 concentrations were significantly higher in Iraqi sample of RA patients compared to controls with direct strong highly significant correlation between these cytokines. This may help in diagnosis of RA and suggest potentially an effective treatment.

Key words: Rheumatoid arthritis, IL17, IL6, rheumatoid arthritis and cytokines.