RESUMEN
Background: The sensitivity of sputum and bronchoalveolar lavage (BAL) for diagnosis of pulmonary tuberculosis (PTB) is low. Objective: To evaluate the value of sputum obtained post-bronchoscopically in the detection of AFB (smear and culture), with particular comparison to the standard pre-bronchoscopic culture, BAL and transbronchial biopsy (TBB). Method: Thirty-five active PTB patients (diagnosed clinically and radiologically) with 3 negative consecutive sputum AFB smears were recruited. Some of the sputums were also cultured. All patients underwent fiberoptic bronchoscopic examinations (FOB) with BAL and TBB performed from the indicated segments. The BAL specimens were processed for AFB stains and C/S. Post-bronchoscopic cultures patients were asked to expectorate 3 consecutive sputums for examinations (smear and C/S). Final diagnosis of PTB was defined as a recovery of AFB (smear ± C/S) at any step of the diagnostic procedures. In cases with negative AFB recovery, active PTB was diagnosed only if definite clinical plus radiologic improvement after chemotherapy was evidenced. Results: Of the thirty-five patients participated in this study, PTB was diagnosed in eighteen patients. The addition of post-FOB sputum smear alone did not increase the sensitivity over group 2 (p=0.11). The sensitivity of group 3 (72%) was higher than that of group 1 (30%, p=0.03) and that of group 2 (61%, p=0.016). No statistically difference was seen between group 1 and 2 (p=0.28). Conclusion: The addition of post-bronchoscopic sputum culture to BAL examination and TBB increased the sensitivity of PTB detection in sputum smear-negative PTB patients.