Non-cystic fibrosis bronchiectasis: a retrospective review of clinical, radiological, microbiological and lung function profile at a tertiary care center of low-middle income country.

Non-cystic fibrosis (non-CF) bronchiectasis has emerged as a significant respiratory disease in developing countries. Given the variation in causes and clinical characteristics across different regions, it is necessary to conduct studies in regions with limited data such as low-middle income countries (LMIC). The aim of the study was to investigate the underlying causes, clinical presentation, etiology, lung function and imaging in patients with bronchiectasis who sought treatment at a tertiary care hospital in a LMIC. We conducted retrospective observational study at the Aga Khan University, Pakistan. Adult patients diagnosed with non-CF bronchiectasis on high-resolution computed tomography scan between 2000 and 2020 were included. We evaluated the etiology, clinical characteristics, microbiology, radiology and spirometric pattern of these patients. A total of 340 patients were included with 56.5% being female and 44.7% aged over 60 years. Among them, 157 (46.2%) had experienced symptoms for 1-5 years. The most common spirometric pattern observed was obstructive impairment (58.1%). Previous tuberculosis (TB) (52.94%) was the most common etiology followed by allergic bronchopulmonary aspergillosis (7.64%). Bilateral lung involvement on HRCT scan was found in 63.2% of patients. Pseudomonas aeruginosa was the most frequently identified organism (38.75%) among 240 patients with available specimens. Patients with P. aeruginosa infections had a significantly higher number of exacerbations (p=0.016). There was a significant difference (p<0.001) in P. aeruginosa growth among different etiologies. In conclusion, post-TB bronchiectasis was the most common cause of non-CF bronchiectasis in our study population. P. aeruginosa was the predominant organism, and 63.2% of the patients exhibited bilateral lung involvement. Since P. aeruginosa growth and extensive lung involvement have been associated with poor prognosis and increased mortality risk, we recommend close follow ups of these patients to improve quality of life and survival in developing countries like Pakistan.