Incidence and clinical predictors of endobronchial tuberculosis in patients with pulmonary tuberculosis

BACKGROUND AND OBJECTIVE Incidence and predictors of endobronchial tuberculosis (EBTB) remain unknown because of the lack of prospective studies. Our objective was to assess the incidence and predictors of concomitant EBTB in patients with active pulmonary tuberculosis (PTB). METHODS We prospectively performed routine bronchoscopic examination in all patients with PTB to detect EBTB. Clinical and bronchoscopic findings were analyzed to elucidate predictors of EBTB. RESULTS Bronchoscopies of 429 PTB patients were performed at a tertiary referral hospital in Korea. Among those, 233 patients (54.3%) had EBTB. Female gender (odds ratio (OR) 4.35, 95% confidence interval (CI) 1.78-10.63), longer symptom duration (>4 weeks; OR 1.86, 95% CI 1.05-5.46), and no previous history of tuberculosis (OR 4.16, 95% CI 1.22-14.18) were found to be the independent predictors of concomitant EBTB in patients with active PTB. Most of the EBTB/PTB patients had mild stenosis, and more than 20% of them had severe stenosis at the time of diagnosis. Patients with EBTB had follow-up bronchoscopy to evaluate persistent airway stenosis. Persistent bronchostenosis with the lumen narrowed by more than one third occurred in 20.7% (30/145) of patients. The involvement length and decreased forced expiratory volume in 1 s were the risk factors for persistent bronchostenosis. CONCLUSIONS In patients with active PTB, 50% or more have EBTB. Female gender and longer duration of symptoms are the main predictors of concomitant EBTB. Immediate diagnostic bronchoscopy in patients with active PTB should be considered in selected patients for detection of brocnhostenosis.