Clinical, imaging, bronchoscopic characteristics and pulmonary function features in patients with endobronchial tuberculosis: a single-centre cross-sectional study.

OBJECTIVES: Endobronchial tuberculosis (EBTB) is a common manifestation of tuberculosis (TB) that may cause airway obstruction if not promptly diagnosed and treated. This study described clinical, imaging, bronchoscopic characteristics and pulmonary function in patients with EBTB.

DESIGN: A single-centre cross-sectional study.

SETTING: The study was conducted at the National Lung Hospital, a tertiary hospital specialised in TB and lung diseases in Vietnam from May 2023 to May 2024.

PARTICIPANTS: We consecutively enrolled 91 patients aged ≥16 years with bacteriologically confirmed EBTB, defined by positivedetection using GeneXpert MTB/RIF assay or liquid culture from bronchial biopsy or aspirate specimens with or without compatible histopathological findings. All participants underwent a standardised diagnostic workup, including chest high resolution CT (HRCT) scan, spirometry, bronchoscopy and histopathology.

OUTCOME MEASURES: The outcome of our study was the presence of central airway obstruction (CAO), defined as ≥50% narrowing of the trachea, mainstem bronchi, bronchus intermedius, lobar and segmental bronchi visually estimated on bronchoscopy and supported by HRCT findings.

RESULTS: Median age was 37 years (IQR: 27-54), 64.8% female; 31.9% were post-TB treatment cases and 68.1% newly diagnosed. Overall, 65.9% of patients had ventilatory defects, most commonly the restrictive pattern (66.7%). Lesions were more frequent in the left airway than right (64.8% vs 31.9%, p<0.001). CAO was found in 71.4% of patients, more common in post-TB cases (86.2% vs 64.5%). Multivariate logistic regression analyses showed that three variables were independently associated with the risk of CAO on bronchoscopy, including shorter duration from symptom onset to hospitalisation (<8 weeks) (adjusted OR (aOR)&#x2009;=&#x2009;3.93, 95%&#x2009;CI 1.18 to 13.03), dyspnoea (aOR&#x2009;=&#x2009;3.85, 95%&#x2009;CI 1.27 to 11.68)&#x2009;and forced expiratory volume in one second (FEV) <80% (aOR&#x2009;=&#x2009;5.45, 95%&#x2009;CI 1.28 to 23.33).

CONCLUSION: Ventilatory defects and CAO were common among patients with EBTB. A high level of suspicion should be applied to patients presenting with dyspnoea, shorter duration from symptom onset to hospitalisation (<8 weeks) and reduced FEV(< 80%).