Basic research overview in rheumatoid arthritis

Abstract Rheumatoid arthritis (RA) is a common autoimmune disease with a prevalence of 0.5-1.0% worldwide. Although advances in understanding the pathogenesis of RA have led to new therapeutics with good outcomes, the real cause of the disease is still unknown. RA is characterized by synovial inflammation and hyperplasia, which erodes cartilage and bone, and autoantibody production (rheumatoid factor (RF) and anti-citrullinated protein antibody (ACPA)). There are many critical questions on the mechanism of the disease onset and progression: How genetic and environmental factors interact with each other? Why does the inflammatory response localize in joints? What are the key players to perpetuate synovial inflammation? In this review, we summarize pathogenetic advances in these issues especially from the point of view of basic research.