Published: 2021-01-29

Diagnostic yield of bronchoalveolar fluid/bronchoscopy among sputum AFB and CBNAAT negative presumptive tuberculosis patients: an observational study

Sakshi Dubey, Nitin Gaikwad, Shailesh Meshram, Mahavir Bagrecha


Background: Tuberculosis is one of the most common chronic infections globally, especially in developing countries like India and is a leading cause of morbidity and mortality. Therefore, early diagnosis, and microbiological confirmation of pulmonary TB is important to break the chain of transmission. This study was carried out to study usefulness of fiberoptic bronchoscopy in sputum smear negative and CBNAAT negative patient of presumptive tuberculosis.

Methods: It was an observational study in the Department of Respiratory medicine for duration of 2 years (Sept 2018- Aug 2020) among 100 adults cases of presumptive tuberculosis whose sputum were negative on sputum AFB and CBNAAT. Cases with relative or absolute contraindication for bronchoscopy were excluded from study.

Results: Mean age of study subjects was 47.31±12.29 years; M:F was 1.2:1 and 5% had past history of tuberculosis. Most common findings on chest X-ray was alveolar opacities (40%), inhomogeneous opacity (24%), cavitary lesions (20%), cystic lesion (8%) and fibrosis (6%) in different zones of lung. BAL sent for CBNAAT testing detected 15% mycobacterial TB, 2% mycobacterial TB with Rif resistance. Zn staining testing detected 10% AFB, on culture 14% showed AFB growth,4% had malignant cell findings. Diagnostic efficacy of Zn staining of BAL showed 42.86% sensitivity, 95.35% specificity, 60% PPV, 91.11% NPV and 88% diagnostic accuracy. BAL CBNAAT testing had 78.57% sensitivity, 93.02% specificity, 64.71% PPV, 96.39% NPV and 91% diagnostic accuracy. Most common complication was bronchospasm and hypoxia.

Conclusions: Fiberoptic bronchoscopy is useful investigation in establishing accurate and early diagnosis of lower respiratory tract infection.


AFB, BAL, CBNAAT, Tuberculosis, Yield

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World Health Organization. Treatment of Tuberculosis: Guidelines for National Programmes. 3rd ed. Switzerland, Geneva: WHO; 2003. Available at https:// apps. who. int/ iris/bitstream/handle/10665/44165/9789241547833_eng.pdf. Accessed on 29 September 2020.

Global Tuberculosis Report (PDF). WHO. WHO. 2019. WHO/CDS/TB/2019.23 © World Health Organization 2019. Available at https:// www. who. int/teams/global-tuberculosis-programme/tb-reports. Accessed on 29 September 2020.

World Health Organization. Global Tuberculosis Report, 2016. WHO/HTM/TB/2016.13. Geneva, Switzerland: World Health Organization; 2016. Available at https:// apps. who. int/iris /bitstream/handle/10665/250441/9789241565394-eng.pdf?sequence=1. Accessed on 29 September 2020.

Harris AD, Mphases NB, Mundy C, Banerjee A, Kwanjana IH, Salanipom FM, et al. Screening tuberculosis suspected using two sputum smear. Int J Tuberc Lung Dis. 2000;4:36-40.

Gonzalez Y, Wiysonge CS, Geldenhuys H, Hanekom W, Mahomed H, Hussey G, et al. Sputum induction for the diagnosis of pulmonary tuberculosis: a systematic review and meta-analysis. Eur J Clin Microbiol Infect Dis. 2012;31(7):1619-30.

Kapur M, Luhadia A, Luhadia SK. Role of induced sputum with hypertonic saline in the early diagnosis of no / inadequate sputum or sputum smear negative suspected cases of pulmonary tuberculosis. Int J Res Med Sci. 2017;5:4761-4.

Alzeer AH, Al-Otair HA, Al-Hajjaj MS. Yield and complications of flexible fiberoptic bronchoscopy in a teaching hospital. Saudi Med J. 2008;29(1):55-9.

Colebunders R, Bastian I. A review of diagnosis and treatment of smear negative pulmonary tuberculosis. Int J Tuberc Lung Dis. 200;4(2):97-107.

Harris AD, Mphases NB, Mundy C, Banerjee A, Kwanjana IH, Salanipom FM, et al. Screening tuberculosis suspected using two sputum smear. Int J Tuberc Lung Dis. 2000;4:36-40.

Nussbaum E. Pediatric fiberoptic bronchoscopy: Clinical experience with 2,836 bronchoscopies. Pediatr Crit Care Med. 2000;3(2):71-6.

Harrison BD. Guidelines for care during bronchoscopy. British Thoracic Society. Thorax. 1993;48(5):584.

Panda RK, Dash DJ. To study the usefulness of cartridge based nuclear acid amplification test (CBNAAT) in bronchoalveolar samples in the diagnosis of sputum negative patients with presumptive pulmonary tuberculosis. Int J Pul Res Sci. 2019;4(2):555632.

Iyer VN, Joshi AY, Boyce TG, Brutinel MW, Scalcini MC, et al. Bronchoscopy in suspected pulmonary TB with negative induced-sputum smear and MTD Gen-probe testing. Respir Med. 2011;105(7):1084-90.

Shrestha P, Arjyal A, Caws M, Krishna GP, Abhilasha K. The application of GeneXpert MTB/RIF for smear negative TB diagnosis as a Fee-paying service at a south Asian general hospital. Tuberculosis Res Treatment. 2015:1-6.

Khalil KF, Butt T. Diagnostic yield of bronchoalveolar lavage gene xpert in smear- negative and sputum-scarce pulmonary tuberculosi. J College Phys Surg Pakistan. 2015;25(2):115-8.

Palud P, Cattoir V, Malbruny B, Magnier R, Campbell K, et al. Retrospective observational study of diagnostic accuracy of the Xpert® MTB/RIF assay on fiberoptic bronchoscopy sampling for early diagnosis of smear-negative or sputum-scarce patients with suspected tuberculosis. BMC Pulm Med. 2014;14:137.

Avashia S, Choubey S, Mishra S, Atul K. To study the usefulness of CBNAAT (cartridge based nuclear acid amplification test) in BAL (bronchoalveolar lavage) samples in the diagnosis of smear-negative/non-sputum producing patients with suspected tuberculosis. J Evolution Med Dent Sci. 2016;5 (1):55-9.

Hazarika B, Medhi S, Sarma J. Role of CBNAAT in Bronchoalveolar Lavage in sputum smear negative pulmonary tuberculosis. Assam J Int Med. 2017;7:72-9.

Barnard DA, Irusen EM, Bruwer JW, Plekker D, Whitelaw AC, Deetlefs JD, et al. The utility of Xpert MTB/RIF performed on bronchial washings obtained in patients with suspected pulmonary tuberculosis in a high prevalence setting. BMC Pulmonary Med. 2015;15(1):103.

Choudhary CR, Devesh M, Purohit G, Borana H, Desai G, Gupta R. To Study the usefulness of CBNAAT (Cartridge based Nuclear Acid Amplification Test) in BAL (Bronchoalveolar Lavage) samples for the diagnosis of smear-negative /non sputum producing patients with suspected tuberculosis. IJSR. 2019;8(3):1371-4.

Quaiser S, Agarwal A, Khan R, Haque SF. Fiberoptic bronchoscopy, as a valuable diagnostic option in sputum negative pulmonary tuberculosis: A prospective study. Int J Appl Basic Med Res. 2012;2(2):123-7.

Kilarua SC. Role of Xpert MTB/RIF in Bronchoalveolar lavage fluid of sputum-scarce, suspected Pulmonary TB patients. J Clin Tuberc Other Mycobact Dis. 2019;14:7-11.

Theron G, Zijenah L, Chanda D, Clowes P, Rachow A, Lesosky M. Feasibility, accuracy, and clinical effect of point-of-care Xpert MTB/RIF testing for tuberculosis in primary-care settings in Africa: a multicentre, randomised, controlled trial. Lancet. 2014;383(9915):424-35.

Theron, G, Peter, J, Richardson M, Barnard M, Donegan, S, Warren R. The cochrane collaboration. cochrane database of systematic reviews. Chichester, UK: John Wiley and Sons, Ltd; 2014. The diagnostic accuracy of the GenoType® MTBDR assay for the detection of resistance to second-line anti-tuberculosis drugs. Available at http:// doi. wiley. com/ 10. 1002/ 14651858. CD010705.pub2. Accessed on 12 October 2020.

Alamoudi OS, Attar SM, Ghabrah TM, Kassimi MA. Bronchoscopy, indications, safety and complications. Saudi Med J. 2000;21(11):1043-7.

Sawy MS, Jayakrishnan B, Behbehani N, Abal AT, El-Shamy A, Nair MG. Flexible fiberoptic bronchoscopy diagnostic yield. Saudi Med J. 2004;25(10):1459-63.

Kaparianos A, Argyropoulou E, Sampsonas F. Indications, results and complications of flexible fiberoptic bronchoscopy: a 5-year experience in a referral population in Greece. Eur Rev Med Pharmacol Sci. 2008;12(6):355-63.

Alzeer AH, Al-Otair HA, Al-Hajjaj MS. Yield and complications of flexible fiberoptic bronchoscopy in a teaching hospital. Saudi Med J. 2008;29(1):55-9.

Kalawat U, Sharma KK, Reddy PRN, Kumar AG. Study of bronchoalveolar lavage in clinically and radiologically suspected cases of pulmonary tuberculosis. Lung India. 2010;27(3):122-4.

Anderson C, Inhaber N, Menzies D. Comparison sputum induction with fibreoptic bronchoscopy in the diagnosis of tuberculosis. Am J Respir Crit Care Med. 1995;152:1570-4.