Comparison of Induced Sputum with Bronchoalveolar Lavage Samples for Pulmonary Tuberculosis diagnosis in sputum scarce Patients


  • Masood Alam
  • Muhammad Imran Shahzad
  • Shahid Pervaiz
  • Muhammad Jamil
  • Muhammad Waqas Afzal
  • Azam Mushtaq


Bronchoalveolar lavage (BAL), Induced Sputum, Pulmonary tuberculosis


Background: One of the most common infections in the world is Tuberculosis (TB), mostly in those countries which are under development. As the initial approach to the diagnosis of pulmonary TB (PTB), the detection of acid-fast bacilli (AFB) in respiratory specimens is recommended by the World Health Organization (WHO). But, the sensitivity of this method is found to be low especially in patients who are unable to produce sputum spontaneouslyObjective: Present study was conducted with the aim to compare the diagnostic performance of induced sputum with bronchoalveolar lavage for pulmonary tuberculosis diagnosis in sputum-scarce patients.Methodology: The present study was conducted at the Pulmonology department of Nishtar Medical University and Hospital, Multan, from February 2016 until September 2018. A total of 108 patients were recruited for the study. One hour before performing bronchoscopy, nebulization with hypertonic saline solution was given to the patients to obtain induced sputum. Then bronchoscopy was performed and BAL samples were collected. Gene expert MTB/Rif was performed in both specimens and sensitivity, specificity, accuracy, positive predictive value, and negative predictive values were calculated.Results: Sensitivity, specificity, positive predictive value, and negative predictive value of induced sputum for AFB smear was 70.6%, 78.8%, 88.3%, and 54.1%, respectively. Sensitivity, specificity, positive predictive value, and negative predictive value of induced sputum for gene expert was 68.6%, 54.5%, 65.7, 85.5% and 30.8%, respectively.Conclusion: Examination of sputum induced sample is a safe, cheap, and non-invasive alternative to bronchoalveolar lavage and provided good sensitivity and specificity with lesser side effects for the diagnosis of pulmonary tuberculosis in patients with no sputum production.






Original Article