Lower FEV ₁ and gram-negative bacilli isolation as independent risk factors for exacerbations in post-TB bronchiectasis

BACKGROUND Post-TB bronchiectasis is a recognised but under-investigated category of bronchiectasis. This study evaluated its clinical features and identified risk factors for acute exacerbations (AEs). METHODS This retrospective observational cohort study analysed data from the Taiwan Bronchiectasis Registry. Patients with bronchiectasis were included, and those with post-TB bronchiectasis were identified for subgroup analysis. We collected demographics, symptoms, lung function, microbiological data, and modified Reiff scores to assess risk factors for AEs. RESULTS A total of 1,444 patients were analysed, including 222 (15%) with post-TB bronchiectasis. Among them, 54 (24%) experienced at least one AE during the study period. Post-TB bronchiectasis patients had more frequent AEs, higher FACED and modified Reiff scores, lower body mass index (BMI) and forced expiratory volume in 1 s (FEV 1 ), and more symptoms than non-post-TB cases. Post-TB bronchiectasis patients with AEs had higher FACED and Reiff scores, lower BMI and FEV 1 , and higher rates of positive sputum cultures for gram-negative bacilli (GNB). Multivariable analysis identified FEV 1 ≤ 60% predicted (adjusted odds ratio [aOR]: 2.334, 95% CI: 1.192–4.572) and positive GNB cultures (aOR: 3.075, 95% CI: 1.362–6.942) as independent risk factors for AEs. CONCLUSION Post-TB bronchiectasis is associated with a higher risk of exacerbations. Reduced FEV 1 and positive GNB cultures are independent risk factors for AEs.