The lung in immune-mediated disorder: rheumatoid arthritis.

Various pleuro-pulmonary abnormalities are known to complicate vascular collagen diseases, particularly, rheumatoid arthritis. Each component of the respiratory system is affected, either separately or in combination. Although most pulmonary complications appear in an established case of collagen vascular disease, in certain conditions, the lung disease precedes the more typical manifestation. While some complications are asymptomatic and tend to be resolved spontaneously (for e.g. pleuritis and rheumatoid nodules), others may cause severe or fatal conditions (interstitial pneumonia and constrictive bronchiolitis). The incidence of interstitial lung disease is increasing in vascular collagen disease. This may be mainly attributed to the increase use of invasive techniques such as bronchoscopy and video-assisted thoracoscopic surgery and in part due to the use of high resolution computed tomography, and functional pulmonary tests.