Pathophysiology of Rheumatoid Arthritis and Other Disorders

Abstract

Rheumatoid arthritis (RA) is a chronic systemic disorder of unknown cause. There are many manifestations, but the typical feature of RA is chronic inflammatory synovitis, usually involving peripheral joints in a symmetric pattern. Although family studies indicate a clear genetic predisposition, it must be considered that this genetic risk does not fully account for the incidence of the disease, suggesting that environmental factors also play a role in the etiology of RA. The findings in the pathophysiology and production of cytokines allow the suggestion that RA is an event mediated by immunologic factors although the initiating stimulus has not yet been characterized. The most typical characteristics of the disease are inflammatory processes in the synovia, which cause cartilage damage and bone erosions and subsequent changes in joint integrity. Despite its destructive potential, the pattern of RA can be quite variable (Table 3.1). Some patients may experience only a mild oligoarticular illness of brief duration with minimal joint damage, whereas others will have progressive polyarthritis with severe functional impairment and also systemic manifestations.