Decreasing Rate of Unknown Bronchiectasis Etiology: Evaluation of 319 Adult Patients with Bronchiectasis

Bronchiectasis can have several causes, but there are only a limited number of studies about the prevalence of these causes. Most of the studies in adults are from previous years. This study aimed to identify etiologies in adult patients with bronchiectasis.

Between January 1996 and June 2015, data from 319 patients admitted to a specialized bronchiectasis clinic were analyzed. Diagnoses were confirmed using high-resolution or multislice computed tomography and were retrospectively evaluated.

Of the 319 patients, 187 (58.6%) were women and 132 (41.4%) were men. The mean age was 49.0±17.4 (range 15-83) years. The mean duration of illness was 19.5±14.9 years. There were several common etiologies: (1) post-infections (215; 67.5%, 70 of the 215 patients had tuberculosis); (2) obstructive lung diseases (28, 8.8%); (3) defects in mucociliary clearance (13, 4.2%); (4) connective tissue diseases (8, 2.4%); (5) immunodeficiency (5, 1.5%); (6) structural lung conditions (1, 0.3%); and (7) obstruction of a single bronchus (1, 0.3%). No causes could be established in 41 (12.9%) patients.

Despite developments in antibiotic therapy and vaccination programs, the most common etiology for bronchiectasis is post-infectious conditions as observed in previous years. However, with improvements in diagnostic tests and procedures, the rate of unknown etiologies has dropped from ≥50% to 12.9%.