Diagnostic value of bronchoscopy in sputum‑negative presumptive pulmonary tuberculosis patients and its clinicoradiological profile

Abstract

Abstract: CONTEXT: Tuberculosis (TB) remains endemic in India. 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 clinical and radiological profile in sputum‑negative, pulmonary TB patients. METHODS: We performed an analysis of patients with 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 11 months. Patients’ symptoms, radiological features, lung lobe lavaged, BAL acid‑fast bacilli (AFB) stain, Mycobacterium TB (MTB)‑PCR, and mycobacterial cultures were analyzed. Mycobacterial culture was used as a reference standard. RESULTS: 54 patients underwent a diagnostic bronchoscopy. Dry cough and fever were the most common symptoms. Uncontrolled diabetes mellitus was the most frequent comorbidity identified in 15 (28%) 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%). BAL mycobacterial culture and MTB Polymerase Chain Reaction (PCR) were positive in 43 (80%) and 41 (76%) patients and BAL AFB was positive in 5 patients respectively. Using BAL culture as reference, male gender, predominant upper lobe disease, upper lobe lavage, and presence of cavities on chest imaging had the highest diagnosticyield (82%, 100%, 63%, and 89%, respectively) (P = 0.02,0.006, 0.03, and 0.02, respectively).There was 100% concordance among the three diagnostic modalities. CONCLUSIONS: An overall diagnostic yield of 80% was achieved with combined use of BAL MTB PCR, culture, and AFB staining. Keywords: Broncho alveolar lavage, bronchoscopy, Mycobacterium tuberculosis polymerase chain reaction, sputum negative, tuberculosis