Background: Induced sputum is widely used in assessing airway inflammation. However, its utility as a diagnostic tool in the diagnosis of lung disease in immunosuppressed patients merits further investigation. Objectives: To determinate the diagnostic yield of sputum induction in the diagnosis of lung diseases in HIV-positive patients. Method: Subjects were selected from among HIV-positive patients older than 14 years who were evaluated at a reference hospital between January 2001 and September 2002. Those with respiratory symptoms for 7 days or longer with normal or abnormal chest X-rays, as well as those without respiratory symptoms but with abnormal chest X-rays, were included. All subjects were submitted to clinical examination, radiologic evaluation, sputum induction and laboratory testing. Subsequently, flexible fiberoptic bronchoscopy, bronchoalveolar lavage and transbronchial lung biopsy were performed. Samples were processed for Gram and Ziehl-Neelsen staining, quantitative culture for pyogenic bacteria, direct staining for fungi, culture for mycobacteria and fungi, silver stain for Pneumocystis jiroveci, as well as for total and differential cellularity determination. Results: A total of 54 patients were included. Upon testing negative for any etiologic agent, 7 patients were excluded, resulting in a total of 54 patients studied. A total of 60 infectious agents were isolated. Among the etiologic agents isolated, 46.7% were P. jiroveci, 33.5 were pyogenic bacteria and 16.7% were Mycobacterium tuberculosis. Sputum induction presented 57.5% sensitivity, 42.9% specificity, 87.1% predictive positive value, 13% predictive negative value and 55.6% overall accuracy. Conclusions: In this population, sputum induction proved to be a technique that is safe and easily performed, with a good diagnostic yield.

Keywords: HIV, Acquired Immunodeficiency Syndrome, Bronchoscopy, Sputum, Lung Disease/diagnosi.