Comparison between induced-sputum and bronchoalveolar lavage fluid in diagnosis of pulmonary tuberculosis

Abstract

Background: Diagnosis of pulmonary tuberculosis in patients with negative smear result or sputum culture and patients who are unable to produce sputum requires other tough techniques. This study compares the smear and culture results obtained by induced-sputum as a non invasive method with samples taken by bronchoalveolar lavage (BAL). Patients and methods: A total of 82 patients subjected for bronchoscopy were enrolled. They had 3 negative sputum samples, or were unable to produce sputum. Induced-sputum specimens were taken from all patients before performing bronchoscopy. Results: A total of 18 BAL culture samples were positive, among whom 16 had positive culture in induced-sputum sampling (kappa test: 0.92, p=0.0001). There was a significant relation between radiologic findings and smear and culture results. Conclusion: Induced-sputum is a non-invasive method when compared with BAL. It is a reassuring alternative of BAL which is a semi-invasive and expensive approach. If the radiologic findings are compatible with pulmonary TB, possibility of positive induced-sputum samples can be increased. é 2009 IDTMRC, Infectious Diseases and Tropical Medicine Research Center.