Predictors of Acute Exacerbations in Patients With Post-tuberculosis Bronchiectasis: A Multicenter Retrospective Study

Abstract Background: Bronchiectasis is a heterogeneous disease with various etiologies. Taiwan was historically a region with a high prevalence of pulmonary tuberculosis (TB). This study aims to evaluate the clinical outcomes of patients with post-TB bronchiectasis and identify risk factors predictive of future acute exacerbations (AEs) in this patient group.Materials and Methods: Patients diagnosed with bronchiectasis via computed tomography (CT) were initially screened between January 2017 and June 2020. All enrolled patients were followed up for 1 year. The study included patients with comprehensive demographic data, symptoms, lung function, microbiological information, and modified Reiff scores for analysis. Patients with post-TB bronchiectasis were further identified, and the risk factors associated with AEs were evaluated.ResultsA total of 1444 patients were included for analysis; 222 patients (15%) had post-TB bronchiectasis. Among these patients, 54 (24%) experienced at least one AE episode during the study period. The average age was 67 years among patients with post-TB bronchiectasis. Patients with post-TB bronchiectasis had a significantly lower body mass index (BMI), reduced forced expiratory volume in one second (FEV1), more frequent symptoms such as hemoptysis and dyspnea, and higher Reiff scores, compared to patients with bronchiectasis due to other etiologies. Although not significant, there was an increased rate of positive sputum cultures for gram-negative bacillus (GNB), especially Pseudomonas aeruginosa, in post-TB bronchiectasis patients. Patients with post-TB bronchiectasis experienced a significantly higher rate of AEs compared to those with other etiologies (24.3% vs. 17.4%, p = 0.014) (Table 1). Patients who developed AEs had lower BMI and FEV1 and higher rates of positive cultures for Pseudomonas aeruginosa, Klebsiella pneumoniae, and overall GNB. They also demonstrated higher Reiff scores. Those with AEs had a higher mortality rate than those without AEs (13.0% vs. 1.8%, p < 0.001) (Table 2). Multivariate analysis identified that lower FEV1 (aOR 0.122, 95% CI 0.026-0.580; P = 0.008) and positive GNB cultures (aOR 3.121, 95% CI 1.372-7.100; P = 0.007) were independent predictors of AEs for patients with post-TB bronchiectasis (Table 3). Combining these two factors, post-TB bronchiectasis patients with FEV1 below 60% and positive GNB cultures had a 50% risk of future AEs (Figure 1).Conclusion: Bronchiectasis is a heterogeneous disease, and patients with post-TB bronchiectasis are at a higher risk of future exacerbations compared to those without a history of TB. In these patients, reduced lower FEV1 and positive cultures for GNB are independent solid predictors of further AEs.