[Drug-induced lung changes in rheumatology]

In rheumatologic disorders cytostatics and immunosuppressive agents are frequently applied and may lead to damage of the lung parenchyma. In the pathogenesis, toxic and immunologic mechanisms are discussed. In the differential diagnosis, pulmonary manifestations of the underlying disorder and infections are important. The diagnosis is confirmed by historical, clinical, histological, and cytologic findings (bronchoalveolar lavage). This review focuses on aspirin, gold, D-penicillamine, methotrexate, cyclophosphamide, and azathioprine treatments. Pulmonary side effects are rare, but early diagnosis is important, because withdrawal of the drug may lead to full recovery of the patient. The prognosis is poor in D-penicillamine or cyclophosphamide induced pneumonitis with a lethal course in 40-50%. The interval between start of treatment and manifestation of lung damage can range from a few weeks to several years. Beside pulmonary symptoms such as cough and dyspnea, fever may occur. Pulmonary function tests show restriction and impairment of diffusion. Gold and methotrexate can induce blood eosinophilia. In bronchoalveolar lavage, the most frequent finding is an increase in lymphocytes with a decrease of the CD4/CD8 ratio. Some drugs, however, can also lead to an increase of the neutrophils and/or the eosinophils in the lavage fluid. Bronchoalveolar lavage can contribute to the exclusion of infections or pulmonary manifestations of the underlying disorder.