Clinical characteristics of pulmonary nocardiosis in patients with and without bronchiectasis: a single-center retrospective comparative study

Abstract

Background Bronchiectasis is a common structural lung disease associated with pulmonary nocardiosis (PN), but the differences between PN patients with and without bronchiectasis remain insufficiently characterized. Methods We conducted a single-center retrospective study of hospitalized patients with PN at Beijing Chaoyang Hospital from January 2012 to December 2024. Patients were grouped by bronchiectasis status, and their clinical, radiological, and microbiological features were compared. Multivariable logistic regression was used to identify factors independently associated with bronchiectasis. Results Among 154 patients, 86 (55.8%) had bronchiectasis. Of 162 Nocardia isolates, N. cyriacigeorgica, N. farcinica, and N. abscessus were the most commonly identified species. Patients with bronchiectasis more frequently had hemoptysis (40.7% vs. 13.2%, P<0.001) and tree-in-bud signs (11.6% vs. 2.9%, P=0.046), but less frequently had respiratory failure (10.5% vs. 26.5%, P=0.022) and had shorter hospital stays (12.62 ± 9.01 vs. 16.96 ± 10.84 days, P=0.007). Patients without bronchiectasis more frequently had type 2 diabetes, bronchial asthma, and several parenchymal or pleural imaging findings. In multivariable analysis, hemoptysis was positively associated with bronchiectasis [adjusted odds ratio (OR), 5.407; 95% confidence interval (CI), 2.185–13.382], whereas type 2 diabetes (adjusted OR, 0.320; 95% CI, 0.115–0.888) and bronchial asthma (adjusted OR, 0.166; 95% CI, 0.030–0.928) were negatively associated with bronchiectasis. Conclusion PN showed distinct clinical and radiological patterns according to bronchiectasis status. Greater diagnostic attention may be warranted in patients without bronchiectasis.