Fig. 1.

Model of rheumatoid arthritis (RA) development and potential interventions to prevent progression of disease. In this model of RA development, disease likely begins with genetic risk and exposure to environmental risk factors (phase 1) that trigger asymptomatic inflammation and autoimmunity (phase 2). Over time, autoimmunity progresses to symptomatic inflammatory arthritis (phase 3) that may further progress to classifiable RA (phase 4). The mechanisms of transition between these phases are not well understood but likely involve complex relationships between host and environmental factors that may differ between phases. Prevention of the progression of disease may be implemented at several points along this pathway of disease development