RT Book, Section A1 Reta, Alison M. A1 O'Callaghan, Rory E. A1 Chen, Steven W. A2 Sutton, S. Scott SR Print(0) ID 7254336 T1 Chapter 47. Rheumatoid Arthritis T2 McGraw-Hill's NAPLEX® Review Guide YR 2011 FD 2011 PB The McGraw-Hill Companies PP New York, NY SN 978-0-07-175562-7 LK accesspharmacy.mhmedical.com/content.aspx?aid=7254336 RD 2024/03/28 AB Rheumatoid arthritis (RA) is a chronic systemic disorder that strikes approximately 1% of the world's population.1,2 The onset is usually at a young age (15-45 years), and occurs more frequently in women than in men.3 The exact etiology of RA is not well understood, and the factors that initiate the inflammatory process are unknown, but it is clearly an autoimmune disease involving T-lymphocytes, B-lymphocytes, macrophages, and cytokines.3 The body's immune cells are unable to differentiate between self and nonself, and begin to target the joint tissue. T-lymphocytes produce proinflammatory cytokines and produce cytotoxic substances that lead to the erosion of bone and cartilage. Activated B-lymphocytes produce plasma cells, which form antibodies that attack joint tissues. Macrophages begin to release prostaglandins and cytotoxins to cause further injury and inflammation.3