Diagnostic value of bronchoalveolar lavage in the subset of patients with negative sputum/smear and mycobacterial culture and a suspicion of pulmonary tuberculosis

• Published in: International journal of infectious diseases 2019-05, Vol.82, p.96-101
• Main Authors: Ahmad, Mushtaq, Ibrahim, Wanis H., Sarafandi, Sabir Al, Shahzada, Khezar S., Ahmed, Shakeel, Haq, Irfan Ul, Raza, Tasleem, Hameed, Mansoor Ali, Thomas, Merlin, Swehli, Hisham Ab Ib, Sattar, Hisham A.
• Format: Article
• Language: English
• Subjects: Bronchoalveolar lavage; Culture negative; Pulmonary tuberculosis; Smear negative
• ISSN: 1201-9712; 1878-3511
• DOI: 10.1016/j.ijid.2019.03.021

The diagnostic value of bronchoalveolar lavage in the subset of patients with both negative sputum/smear and culture is seldom reported. Bronchoalveolar lavage should be pursued as a useful diagnostic tool for suspected pulmonary tuberculosis cases when sputum/smear and culture are negative. Bronchoalveolar lavage mycobacterial culture and polymerase chain reaction provided the highest diagnostic yield. Higher yield is associated with positive QuantiFERON-TB Gold In-Tube test, positive Purified Protein Derivative skin test, upper zone abnormality on chest radiograph or those from the Indian subcontinent. The diagnostic value of bronchoalveolar lavage in patients with negative sputum/smear for tuberculous bacilli has been well studied. However, its value in the subset of patients with both negative sputum/smear and culture is seldom reported. A retrospective study of patients referred for diagnostic bronchoscopy for the suspicion of pulmonary tuberculosis during the period from April 1st, 2015 to March 30th, 2016, and who had negative sputum/smear and culture for tuberculous bacilli. One hundred and ninety patients fulfilled the inclusion criteria. Bronchoalveolar lavage detected further 61/190 (32.1%) pulmonary tuberculosis cases. Bronchoalveolar lavage mycobacterial culture and polymerase chain reaction (positive in 60/190 (31.6%) and 58/190 (30.5%) of patients respectively) provided the highest diagnostic yield, whereas direct smear provided the lowest yield. Bronchoalveolar lavage had a sensitivity of 89.7%, a specificity of 100%, a positive predictive value of 100%, a negative predictive value of 94.6%, and a test accuracy of 96.3% in suspected pulmonary tuberculosis cases with negative sputum/smear and culture. Positive bronchoalveolar lavage yield for tuberculosis was significantly associated with a positive QuantiFERON-TB Gold In-Tube test, positive purified protein derivative skin test, radiological evidence of upper zone abnormality and patient’s origin being from the Indian subcontinent. Bronchoalveolar lavage should be pursued as a useful diagnostic tool for suspected pulmonary tuberculosis cases when sputum/smear and culture are negative. Its value is higher in the subset of patients with positive QuantiFERON-TB Gold In-Tube test, positive purified protein derivative skin test, upper zone abnormality on radiograph or being from the Indian subcontinent.