Lung disease in rheumatoid arthritis.

Rheumatoid arthritis (RA) affects approximately 1% of the US population frequently has extra-articular manifestations. Most compartments of the lung are susceptible to disease. Interstitial lung disease (ILD) and airways disease are the most common forms of RA-related lung disease. RA-ILD carries the worst prognosis and most often manifests in a histologic pattern of usual interstitial pneumonia or nonspecific interstitial pneumonia. There have been no large, well-controlled prospective studies investigating therapies for RA-ILD. Treatment usually entails immunomodulatory agents. Further studies are needed to better understand pathogenic mechanisms of disease that lead to lung involvement in these patients.