Evaluating microRNA-499 expression and serum IL-17, ACCP and PADI4 cytokine levels in rheumatoid arthritis patients undergoing anti-TNF alpha therapy

Abstract

Introduction: Rheumatoid arthritis (RA) is a chronic inflammatory autoimmune disease characterized by joint inflammation and damage. While anti-TNF-alpha therapies like infliximab have revolutionized RA, treatment response varies among patients. Identifying reliable biomarkers for treatment response is crucial for optimizing therapy and patient outcomes. MicroRNA-499 has been implicated in autoimmune diseases, and IL-17 is a key mediator in RA pathogenesis. Additionally, PADI4 and ACCP are linked to RA autoimmunity. This study aimed to investigate the potential of microRNA-499 expression, serum levels of IL-17, PADI4 and ACCP as biomarkers for predicting and monitoring treatment response in RA patients undergoing anti-TNF-alpha (infliximab) therapy. Methodology: In this case-control research, blood samples from 100 Iraqi patients with RA and 100 controls were collected. RNA was extracted and the levels of miRNA499 were quantified using real-time PCR. The serum IL-17, PADI4 and ACCP levels were determined using ELISA. Patients were sub-grouped as responders and non-responders based on their responses to anti-TNF-alpha (infliximab) treatment. Results: The mean age of the patients in this study was 46.22 years. The occurrence of RA was higher in age group (31-45) years. There was a significant association between RA, smoking and BMI. miRNA-499 expression was significantly higher in RA patients versus controls (1.1 folds in patients compared to 0.52 in control group). The serum levels of IL-17, PADI4 and ACCP was significantly higher in RA patients than controls (54.3ng/L, 2.52 ng/ml and 2.15 U/ml) vs (40.35ng/ L, 1.78 ng/ml and 1.06 U/ml) respectively. Subdividing of patients showed that miRNA-499 expression and serum IL-17, PADI4 and ACCP to be significantly higher in non-responders patients than responders. Conclusion: MicroRNA-499 expression, serum levels of IL-17, PADI4 and ACCP were found to be significantly higher in RA patients compared to control group as well as in non-responding than responding patients.