Evaluation of Toll-like Receptor 2 Gene Expression in Rheumatoid Arthritis and Correlation with the Disease Activity

Background: Rheumatoid Arthritis (RA) is an autoimmune, chronic, and systematic disease. It affects joints and bones. The exact etiology of RA is still unclear. Varied genetic and environmental factors have been associated with the increased risk for RA. Overactivation of Toll-Like Receptors (TLRs) could initiate the development of autoimmune diseases including RA. Objective: The aim of the study was to evaluate TLR2 gene expression in rheumatoid arthritis patients and investigate its correlation with the disease activity. Materials and Methods: This study included 60 patients and 20 healthy individuals. The patients were diagnosed with RA according to the 2010 American College of Rheumatology/ European League Against Rheumatism criteria (ACR/EULAR). All included subjects did not have any joint disorders and /or autoimmune diseases. RA disease activity was determined by the disease activity score of 28 joints. Whole blood was collected from all participants. Total RNA extraction was done. TLR2 mRNA expression was assessed by reverse transcription-PCR (RT-PCR). Results: TLR2 mRNA expression was found to be significantly higher in RA patients compared to healthy controls. Also, a strong positive correlation was found between TLR2 expression level and the disease activity score. A non significant positive correlation was found between TLR2 expression and serum Rheumatoid Factor (RF) level. Conclusion: TLR2 pathway may have an important role in RA pathogenesis and could be a new biomarker for diagnosis and monitoring disease activity.