Bronchoscopy with bronchoalveolar lavage in tuberculosis and fungal infections

Abstract

Study objective: To determine the utility of bronchoscopy with bronchoalveolar lavage for diagnosing M tuberculosis and fungal infections.

Design: Retrospective review of patients over a six-year period.

Setting: In- and outpatients of one University hospital and affiliated Veterans Administration Medical Center.

Patients: Those who were subsequently found to have either M tuberculosis or fungal infections.

Interventions: Bronchoscopy with bronchoalveolar lavage specimens were compared to prebronchoscopy sputum, when available. Specimens were sent for smear and culture for both acid-fast bacilli and fungi. In the case of lavage, an aliquot also was studied for cellular differential.

Measurements and results: For TB, sputum was smear-positive in 6/47 (34 percent) and culture positive in 24/47 (51 percent), while bronchoscopy was smear positive in 34/50 (68 percent) and culture positive in 46/50 (92 percent). For fungal infections, no sputum was smear-positive and only 1/22 (5 percent) was sputum culture-positive, while bronchoscopy was smear-positive in 14/41 (34 percent) and culture positive in 35/41 (85 percent). Bronchoscopy washings and BAL provided complementary specimens. Eighty-three patients had adequate lavages and the cellularity was significantly different from controls (lymphocytes: TB 18 +/- 11.2 percent [mean +/- SD]; fungal: 13 +/- 11.1 percent; controls 6 +/- 3.1 percent; p less than 0.001; neutrophils: TB 9 +/- 11.5 percent; fungal: 6 +/- 9.1 percent controls: 2 +/- 1.5 percent, p less than 0.01); however, there was overlap and no pattern was characteristic for TB or fungal infections.

Conclusion: Bronchoscopy with BAL is useful in diagnosing tuberculosis and fungal infections.