Diagnostic value of bronchoscopy in sputum-negative pulmonary tuberculosis patients and its correlation with clinicoradiological features

Abstract

CONTEXT: Tuberculosis (TB) remains endemic in Saudi Arabia. Little local data have been reported on bronchoscopic evaluation of sputum-negative pulmonary TB patients, which poses a significant diagnostic and therapeutic challenge. AIMS: To determine the diagnostic value of bronchoscopy and bronchoalveolar lavage (BAL) and its correlation with clinical and radiological features in sputum-negative, culture-confirmed pulmonary TB patients. METHODS: We performed a retrospective analysis of patients with definite or probable pulmonary TB with overall negative (smear and/or polymerase chain reaction [PCR]) or scanty sputum that had undergone bronchoscopy with BAL over a period of 5 years. Patients’ symptoms, radiological features, lung lobe lavaged, BAL acid-fast bacilli (AFB) stain, Mycobacterium TB (MTB)-PCR, and mycobacterial cultures were analyzed. Mycobacterial cultures (either sputum or BAL) were used as a reference standard. RESULTS: Out of 154 patients, 49 (32%) were overall sputum negative and underwent a diagnostic bronchoscopy. Dry cough and fever were the most common symptoms. Uncontrolled diabetes mellitus was the most frequent comorbidity identified in 15 (31%) patients. Fifty-nine percent of the patients had diffuse lung infiltrates, with consolidation being the most common abnormality (41%), followed by cavitation (39%). Right upper lobe was the most frequent lung lobe lavaged (31%), while transbronchial lung biopsies (TBLB) were obtained in 21 (43%). BAL mycobacterial culture and MTB PCR were positive in 35 (71%) and 23 (47%) patients, respectively. Combined BAL MTB PCR and TBLB provided rapid diagnosis in 28 (57%) patients. CONCLUSIONS: An overall diagnostic yield of 90% was achieved with combined use of BAL MTB PCR, culture, and histopathology. Upper lobe lavage and presence of cavities on chest imaging had a higher diagnostic yield.

Analysis of the utility of transbronchial lung biopsy culture under endobronchial ultrasonography with a guide-sheath

“…Generally, TBLB culture is not considered useful for diagnosing mycobacteria, including TB and mycobacterium avium complex 2 , 3 . In sputum-negative TB patients, there is no difference in the diagnostic rate between combined BAL and TBLB histology and combined BAL, TBLB histology, and TBLB culture 8 . All MAC patients who exhibited positive TBLB findings also showed positive acid fast bacilli in smear or/and culture 9 .…”

Clinical and Imaging Characteristics of Smear Negative Pulmonary Tuberculosis Patients: A Comparative Study

“…In some cases, this may reflect the simple fact that even culture is not perfectly sensitive and may in part relate to ambiguities of obtaining consistent sputum samples. On the other hand, more comprehensive samples like bronchoalveolar lavage (BAL) have been shown to detect over 80% of clinically diagnosed smears and GeneXpert-negative TB [ 31 ]. This reveals that part of the problem may be in obtaining an appropriate bacillus-containing specimen by routine sputum sampling method.…”

The Added Value of Bronchoalveolar Lavage for Pulmonary Tuberculosis Diagnosis in High-Risk Hospitalized Patients with Negative Sputum Samples

“…Our aim was to assess the value of BAL in a real-world scenario. The few studies addressing this issue mainly include patients with a known final diagnosis of PTB and look at the diagnostic yield of bronchoscopy among them [18,26,27]. This method of selection can induce selection bias, underlined by the studies' high diagnostic yield of bronchoscopy (57-83%), and does not reflect real-life decision-making for patients hospitalized with HS-PTB.…”

“…However, the added diagnostic value of BAL in HS-PTB cases remains unknown. A limited number of studies reported the yield of BAL in this patient population, and their results showed high variability of diagnostic performances [16][17][18][19]. Among these studies, only a few included consecutive patients, were conducted in the in-patient setting, or used cohorts of patients with other final diagnoses to understand its added diagnostic value.…”