Lung involvement in rheumatoid arthritis.

RA is a systemic autoimmune disorder primarily involving the joints. Extra-articular manifestations of RA often include lung involvement with heterogeneous clinical presentation and radiological findings. Autopsy studies reveal that the percentage of RA patients with pathological changes in the lung is significantly higher than that of patients with clinical manifestations. Lung alterations in RA may be primary or secondary to pharmacological treatments and may involve the alveoli, the interstitium, the airways and/or the pleura. These alterations may significantly impair lung function and some of them are potentially life-threatening. Thus, clinical examination and lung function testing should be performed in all patients with RA at the time of diagnosis and during follow-up. Those patients with clinical alterations and/or impaired lung function should undergo a complete radiological study.