The Value of Bronchoalveolar Lavage in the Diagnosis of Sputum Smear-NegativePulmonary Tuberculosis

Background and Objectives: Sputum smear staining for acid-fast bacilli is initial approach to the diagnosis of pulmonary tuberculosis (PTB) but more than 50% of cases are sputum smear-negative. This study was aimed to investigate the diagnostic value of fiberoptic bronchoscopy (FOB) guided bronchoalveolar lavage (BAL) in patients suspected to have tuberculosis. Methods: This prospective cross-sectional study was carried out on 290 sputum smear-negative patients who were clinically suspicious for PTB in 2006-12. All patients were subjected to FOB andBAL, then BAL specimens stained and cultured. Results: Of the 290 patients, 173 cases (59.7%) were men and 117 cases (40.3%) were women with the age of 52.6±19.1 years (ranged 20-76 years). Of the total 290 BAL specimens, 110 specimens (38%) were positive for acid-fast bacilli. Sensitivity, specificity, PPV and NPV was 60%, 91%, 89% and 64%, respectively. Also, LR+ and LR- was 64.6% and 0.44%, respectively. Conclusion: FOB guided BAL is a reliable, rapid and useful method for establishing the diagnosis of smear negative PTB with minimal complications.