MicroRNAs as Regulators of Interleukin-6 Expression in Patients with Rheumatoid Arthritis

Abstract

Interleukin-6 (IL-6) is a prototype cytokine with pleiotropic and excessive functional activity. It regulates inflammatory infiltrate maturation, promotes neutrophil migration and mononuclear cell infiltration, and acts as a chemoreceptor for monocytes in the inflammation focus. These mechanisms are crucial in rheumatoid arthritis (RA) development and therapy. Small non-coding ribonucleic acids (microRNAs) can regulate IL-6 levels in peripheral blood and the inflammation focus by targeting the  IL6  gene expression. Understanding the role of microRNAs in RA can help develop innovative diagnostic methods and personalized treatment approaches. This review aims to update knowledge on epigenetic biomarkers of RA and systematize the results of clinical studies evaluating the relationship between circulating microRNA expression and circulating IL-6 levels in RA patients. The authors searched PubMed, ClinicalKey, Scopus, Cochrane Database, Google Scholar, and eLIBRARY.ru for relevant publications using specific keywords and their combinations. Publications from 2014 to 2025, including original clinical studies of RA, were analyzed. This descriptive review demonstrates that circulating microRNAs can be considered promising molecular biomarkers of RA. However, implementing epigenetic study results into routine rheumatological practice remains challenging due to the ambiguous results of previous studies and the necessity to account for both direct and inverse relationships between changes in specific circulating microRNAs and IL-6 levels in the blood of RA patients.