MicroRNA-146a Expression as a Potential Biomarker for Rheumatoid Arthritis in Egypt

Abstract

Rheumatoid arthritis (RA) is a chronic systemic autoimmune disease. It mainly affects the joints in addition to other organs such as lungs, heart, and eyes. The severity of RA varies widely from mild illness to severe destruction of joints with resultant chronic pain and deformity. The exact cause of RA is unknown. The most accepted theory is that there is an interaction between patient’s genotype and environmental triggers such as smoking, certain infections, and vitamin deficiencies. The global age-standardized prevalence rate is higher in women, increasing with age and peaking between 75 to 79 years in women and 70 to 74 years in men in 2017. In addition to the clinical diagnosis of RA, serologic tests are also important parameters for its diagnosis. The two serologic markers rheumatoid factor (RF) and anti-cyclic citrullinated peptide antibodies (anti-CCP) show the highest diagnostic value for RA. However, one third of RA patients remain sero-negatine for the two markers and still, there is a need for novel biomarkers in order to improve RA diagnosis. MicroRNAs (miRNAs) are non-coding RNAs that bind target messenger RNA and control protein expression (post-transcriptional regulation). There are more than1500 miRNAs reported for humans, with more than 300 miRNAs associated with various diseases. MiRNA-146a was first described in human acute monocytic leukemia cell line by Taganov et al., (2006) who identified its role as a negative regulator of inflammation.