Yield Of Bronchoalveolar Lavage In Suspected Pulmonary TB With Negative Induced-Sputum Smear

Abstract

Background: Bronchoalveolar lavage (BAL) has been used to recover mycobacterium tuberculosis (MTB) from the respiratory tract of patients with lung infiltrates as nearly 50% of pulmonary tuberculosis (PTB) cases are sputum smear negative for acid fast bacilli (AFB). We prospectively compared the diagnostic yield of induced sputum (IS) smear with BALsmear and culture to assess its role in the early diagnosis of sputum negative PTB.
Methods: We performed bronchoscopy to obtain BAL in 52 consecutive patients of suspected PTB between December 2013 and November 2015 after negative results on 2 samples of IS smears. BALsamples were stained with Ziehl-Neelsen (ZN) stain and cultured on L-J media.
Results: Cohort of 52 IS negative patients had a mean age of 46 years (SD 15.6) with 58% male participants. Comorbidities were present in 31% participants whereas 42% were current smokers. Tuberculosis was the final diagnosis in 37% (n =19) patients and rest 63% (n = 33) had nontubercular etiologies like bronchiectasis (n = 6), pneumonia (n = 5), interstitial lung disease (n = 3), lung abscess (n = 2), lung cancer (n = 1), PCP (n = 1), hydatid cyst (n = 2), pneumonia (n = 5) and non- specific infection (n = 13). In tuberculosis group 33% patients had bronchoscopic abnormalities. Tuberculosis was confirmed by BALMTB culture in 90% (n = 17) and by biopsy in 10% (n = 2).
Conclusion: BAL has high diagnostic yield and should be considered in the evaluation of suspected PTB. Bronchoscopy also picked up alternative diagnoses. JMS 2016; 19(2):75-81.