Comparison of bronchoscopic washing and gastric lavage in the diagnosis of smear-negative pulmonary tuberculosis.

Objective: To evaluate the diagnostic contribution and utility of bacteriologic surveys using bronchoscopic washing and gastric lavage in cases of radiologically suspected tuberculosis with no detectable acid-fast bacilli (AFB) in the sputum.

Material And Methods: This prospective study performed bronchoscopic lavage following gastric washing in suspected pulmonary tuberculosis patients. The presence of AFB was determined via direct microscopy and materials were cultured in Löwenstein-Jensen medium.

Results: Thirty-eight consecutive patients were enrolled in the study (30 males and 8 females; mean age, 33.8 +/- 10.9 years). Three patients could not give sputum. In 23 of 35 cases (66%), sputum cultures (SC) were positive. In 17 cases (49%), gastric lavage cultures (GLC) were positive. Eighteen cases (55%) had positive bronchoscopic washing cultures (BWC). No statistically significant difference was observed when SC positivity was compared to GLC and BWC, and no difference was observed when the GLC results were compared with BWC. Tuberculosis was confirmed in 30 of 38 (79%) patients when SC and GLC were evaluated together, in 33 of 38 patients (87%) when SC and BWC were evaluated together, and in 36 of 38 (95%) when SC, GLC, and BWC were evaluated together (P = 0.016, P = 0.002, and P = 0.0001, respectively). The increase in positive cultures was statistically significant when gastric lavage was evaluated together with bronchoscopic washing (P = 0.004).

Conclusion: Adding gastric lavage and bronchial washing to sputum culture could increase culture positivity for M tuberculosis bacilli in suspected pulmonary tuberculosis patients with AFB-negative sputum smears.