Abstract
Rheumatoid arthritis (RA) is a systemic disease manifest as a symmetric polyarthritis usually in the setting of elevated autoantibodies (rheumatoid factor). This disease affects 1–2% of the world's population, most frequently in the 25–55 year old age group and has a female predominance (2.5:1). Nearly 50% of patients with RA demonstrate some type of extra-articular manifestation of the disease such as pleuritis, pleuropericarditis, vasculitis, pneumonitis, pulmonary fibrosis, scleritis or nodulosis. Pulmonary involvement in RA is common and can be due to the disease itself as well as to the therapies used to treat it. In fact, lung disease is the second most common cause of death, following infection, for patients with RA and has been reported to effect between 1–40% of patients. RA associated interstitial lung disease (ILD) is often subtle in onset, slowly progressive and of unclear etiology and response to treatment. This article aims to clarify the current clinical, radiographic and pathologic status of RA-ILD.