Validation of induced sputum (IS) with aerosol hypertonic saline solution followed by bronchoalveolar lavage (BAL) through flexible bronchoscopy (FB) in patients without spontaneous sputum for the diagnosis of pulmonary tuberculosis (TB).
Sputum was induced after 3 or more unsatisfactory spontaneous collection for acid fast bacilli (AFB). FB was recommended to collect BAL in a series of 99 patients with clinical suspicion of TB that remained negative after AFB in IS specimens. It comprised 41 female and 58 male individuals, 55 were HIV negative and 44 HIV positive. Microbiology results were analysed from cultures in Middlebrook and Loewenstein-Jensen media from IS and BAL specimens.
Diagnosis of TB was confirmed in 38 patients, 28 with pulmonary and 10 with extrapulmonary involvement; 48 patients had other diagnosis confirmed but 13 other remained undiagnosed; 3 cases of MOTT were identified in HIV negative individuals without TB. In the 28 patients with pulmonary TB, 11 had a BAL procedure: AFB was positive in 8/28 at IS and 1/11 at BAL. M. tuberculosis was identified at cultures in IS specimens (22/28), BAL specimens (8/11) and both IS and BAL (7/28). Other diagnosis made at BAL in 5 HIV positive cases were pneumocystosis (n=2), cryptococcosis (n=2) and histoplasmosis (n=1).
Direct microbiology diagnosis of TB in IS and BAL specimens have not been well accomplished. Improvements for faster results are needed.
TB suspected patients without a positive AFB result in either spontaneous or induced sputum and BAL specimens still must be treated empirically for TB until the culture results are obtained.
Rogerio Xavier, None.