Rheumatoid arthritis-associated lung disease.

Introduction Rheumatoid arthritis is a systemic inflammatory disorder that most commonly affects the joints, causing progressive, symmetric, erosive destruction of cartilage and bone, which is usually associated with autoantibody production. Rheumatoid arthritis affects ∼1% of the population in developed countries. The incidence and prevalence of rheumatoid arthritis in developing countries is thought to be lower, but is difficult to quantify. Although joint disease is the main presentation, there are a number of extra-articular manifestations including subcutaneous nodule formation, vasculitis, inflammatory eye disease and lung disease. Of these manifestations, lung disease is a major contributor to morbidity and mortality. In some cases, respiratory symptoms may precede articular symptoms. It is critical for the pulmonologist to assess for systemic and articular signs and symptoms of connective tissue disease when evaluating a patient with pulmonary disease of unknown aetiology as patients may initially present with pulmonary symptoms. There are a variety of pulmonary manifestations of rheumatoid arthritis, including pulmonary parenchymal disease (interstitial lung disease (ILD)) and inflammation of the pleura (pleural thickening and effusions), airways and pulmonary vasculature (vasculitis and pulmonary hypertension). These changes may reflect chronic immune activation, increased susceptibility to infection (often related to immunomodulatory medications) or direct toxicity from disease modifying or biological therapy. Prognosis varies depending on the type and severity of involvement. Herein, we review the various manifestations of rheumatoid arthritis-associated lung disease, as well as the recent advances in treatment.