Gold-induced pulmonary disease: clinical features, outcome, and differentiation from rheumatoid lung disease

Gold-induced pulmonary disease is difficult to diagnose, especially, in the case in which interstitial pneumonia appears in the course of gold therapy for rheumatoid arthritis. We analyzed the literature to define the clinical features and prognosis of gold-induced pulmonary disease, and to identify those features that distinguish gold-induced pulmonary disease from pulmonary disease secondary to the underlying disease process of rheumatoid arthritis. Relevant articles from the medical literature were identified using a Mediline search, and the bibliographies of the articles were retrieved. These works were critically reviewed for information on the clinical, physiologic, radiographic, pathologic, and bronchoalveolar lavage (BAL) findings. A total of 140 cases of gold-induced pulmonary disease were identified from 110 reports. In 81% of the patients, gold was being used to treat rheumatoid arthritis, bronchial asthma (6%), pemphigus (5%), or other processes (9%). Side effects other than pulmonary toxicity were common, and included skin rash (38%), peripheral eosinophilia (38%), liver dysfunction (15%), and proteinuria (22%). Only the presence of pemphigus or liver dysfunction correlated with a bad prognosis. Gold-induced pulmonary disease most often followed improvement in rheumatoid arthritis, presumably induced by gold therapy. BAL lymphocytosis and computed tomography (CT) scan findings are useful in making a diagnosis of gold-induced pulmonary disease in an appropriate clinical setting. Features that distinguish gold-induced pulmonary disease from rheumatoid lung disease include female predominance, presence of fever or skin rash, absence of subcutaneous nodules or finger clubbing, low titers of rheumatoid factor at onset of lung disease, lymphocytosis in bronchoalveolar lavage fluid (BALF), and alveolar opacities along the bronchovascular bundles on chest CT scan. Gold-induced lung disease is a distinct entity that can be distinguished from rheumatoid lung disease. It usually improves with cessation of therapy or treatment with corticosteriods.