Abstract Background Bronchiectasis patients with concomitant autoimmune diseases represent a distinct clinical entity, but comprehensive characterization remains limited. We aimed to identify etiologically related clusters and describe their clinical, microbiologic, and radiographic features. Methods This study enrolled patients with bronchiectasis at 16 centers in Taiwan and followed them for one year. Detailed demographics, laboratory test results, microbiologic features, radiographic patterns, pulmonary function test findings, and severe exacerbations were collected. Results A total of 2,753 patients were enrolled, of whom 436 (15.8%) underwent autoimmune evaluation. Of these, 69 (15.8%) were diagnosed with autoimmune diseases, including Sjögren’s disease (42.0%), rheumatoid arthritis (26.1%), systemic lupus erythematosus (11.6%), and multiple autoimmune diseases (20.3%). The majority of patients presented between the ages of 51 and 60. Compared with patients without autoimmune diseases, patients with autoimmune bronchiectasis were more likely to be female (81.2% vs. 63.8%, P = 0.005), have a lower body mass index (20.7 vs. 21.9 kg/m², P = 0.02), and were more likely to be never smokers (88.4% vs. 77.2%, P = 0.04). Patients with autoimmune bronchiectasis had lower rates of bacterial isolates (22.3% vs 10.1%, P = 0.02), particularly Pseudomonas aeruginosa (11.2% vs 5.8%, P = 0.18) than those without autoimmune diseases. In patients with multiple autoimmune diseases, the prevalence of nontuberculous isolates was as high as 80% (P = 0.8%). Patients with systemic lupus erythematosus were more likely to have cystic bronchiectasis (37.5% vs 21.3%, P = 0.27) and lower lobe involvement (81.3% vs 36.0%, P = 0.009). Patients with rheumatoid arthritis had the worst lung function and the highest rate of exacerbations requiring emergency department visits (38.9% vs 21.5%, P = 0.08) or hospitalizations (33.3% vs 22.3%, P = 0.28). Conclusions Autoimmune bronchiectasis has a unique phenotype with disease-specific microbiological and radiographic patterns, yet has been neglected. These findings support personalized diagnostic and therapeutic approaches tailored to the underlying autoimmune disorder. This abstract is funded by: National Science and Technology Council, Taiwan
Chien et al. (2026) studied this question.