Rheumatoid arthritis - Wikipedia, the free encyclopediaAlthough the cause of rheumatoid arthritis is unknown, autoimmunity plays a pivotal role in both its chronicity and progression, and RA is considered a systemic autoimmune ...Rheumatoid arthritis: Causes - MayoClinic.comRheumatoid arthritis — Comprehensive overview covers signs, symptoms and treatment of this inflammatory arthritis.Rheumatoid arthritis - PubMed Health - National Center for ...... disorders (conditions in which the immune system attacks healthy parts of the body and causes pain, swelling, and damage) including: rheumatoid arthritis (a ...