Investigation the autoantibodies, IL-17 and IL-22 in rheumatoid arthritis patients

Rheumatoid arthritis (RA) remains a prevalent and progressive autoimmune disease worldwide, associated with substantial medical, psychological, and economic burdens. To evaluate the role of rheumatoid factor (RF), anti-citrullinated protein antibodies (ACPA), and the proinflammatory cytokines interleukin-17 (IL-17) and interleukin-22 (IL-22) in the development of RA, and to assess their association with disease activity and response to treatment. A case-control study was conducted involving 150 participants, including 120 patients with RA diagnosed by a specialist according to the 2010 ACR/EULAR criteria and 30 age- and sex-matched healthy controls. Serum levels of RF, ACPA, IL-17, and IL-22 were measured using enzyme-linked immunosorbent assay (ELISA). Significantly higher serum levels of RF and ACPA were observed in patients with RA compared with the control group. Receiver operating characteristic (ROC) curve analysis identified a cut-off value of 22.95 U/mL for RF, with 97.4% sensitivity and 90% specificity, and a cut-off value of 22.45 U/mL for ACPA, with 100% sensitivity and 100% specificity. Serum levels of IL-17 and IL-22 were also significantly increased in patients with RA compared with controls. ROC analysis revealed cut-off values of 26.86 pg/mL for IL-17 and 30.16 pg/mL for IL-22, both showing high statistical significance. Stratification according to disease severity and treatment type demonstrated that IL-17 and IL-22 levels were significantly higher in patients at stage 4 and in untreated patients compared with those at earlier disease stages and those receiving chemical, biological, or combination therapies. The present study demonstrates that RF and ACPA levels are significantly elevated in patients with RA and exhibit high diagnostic accuracy based on optimal cut-off values. In addition, IL-17 and IL-22 levels are markedly increased, particularly in patients with advanced disease and those who are untreated. These findings indicate a strong association between elevated autoantibody and cytokine levels, disease severity, and treatment response, supporting their potential utility as biomarkers in the clinical management of RA.