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Updated: May 23, 2026
Bronchoalveolar Lavage (BAL) for Research; Obtaining Adequate Sample Yield
Published on: March 24, 2014
Diagnostic yield of post-bronchoscopy sputum smear in pulmonary tuberculosis
Majid Malekmohammad1, Majid Marjani, Payam Tabarsi
1Clinical Tuberculosis and Epidemiology Research Centre, National Research Institute of Tuberculosis and Lung Disease, Masih Daneshvari Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
Background:
The early definitive diagnosis of pulmonary tuberculosis (TB) is important for control of the disease in the community. We performed this study to evaluate the additional gain of post-bronchoscopy sputum in the diagnosis of pulmonary TB.
Methods:
Bronchoscopy and bronchoalveolar lavage were performed for 126 patients suspected of pulmonary TB who either had 3 negative sputum smears for acid-fast bacilli or could not expectorate. After bronchoscopy the patients were asked to give sputum samples for 3 consecutive days. All of the obtained specimens were investigated for Mycobacterium tuberculosis by smear and culture.
Results:
Pulmonary TB was confirmed in 56 patients. Among all confirmed cases, the sensitivity of bronchoalveolar lavage smear was 57.1% (32 of 56), sensitivity of post-bronchoscopy smear was 76.7% (43 of 56), and the yield of a combination of the 2 methods was 83.9% (47 of 56). Results of post-bronchoscopy sputum smears were not significantly related to sex, age, human immunodeficiency virus (HIV) infection, presence of cavitary lesions on chest X-ray, or the ability to expectorate before bronchoscopy (p > 0.05).
Conclusion:
Evaluation of post-bronchoscopy sputum smears is helpful for earlier diagnosis of pulmonary TB and is an inexpensive and accessible assay.
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