Alpha-1 antitrypsin deficiency in bronchiectasis: Evidence for an overlooked entity beyond COPD: A retrospective...

Alpha-1 antitrypsin deficiency (AATD) is an autosomal co-dominant condition caused by mutations in the SERPINA1 gene. Chronic obstructive pulmonary disease/emphysema, asthma, and bronchiectasis are lung diseases associated with AATD. This study was designed to identify AATD in patients with bronchiectasis without emphysema and to demonstrate the frequency and distribution of AATD genotypes according to the type of bronchiectasis. The study was conducted as a single-center retrospective analysis between December 01, 2022 and December 31, 2024 in patients with bronchiectasis without emphysema. Patients' demographic characteristics (age, gender), smoking status (smoker, ex-smoker, nonsmoker), and types of bronchiectasis (cylindrical, varicose, cystic) according to the Reid classification were evaluated. Dried blood spot samples collected from fingertip pricks were used to screen for alpha-1 antitrypsin genotype deficiency. A total of 563 patients, 241 (42.8%) women, and 322 (57.2%) men, with bronchiectasis without emphysema were evaluated, with a mean age of 55.3 ± 14.9 years. An AATD mutation was detected in 16 patients (2.8%). Genotype deficiency was most commonly observed in the cylindrical type (n = 9). The most frequently identified genotypes were PI*M malton in 6 patients (1.1%), PI*P lowell in 4 patients (0.8%), and PI*I in 3 patients (0.6%). Additionally, 2 patients were found to have previously unidentified novel alpha-1 antitrypsin variants. One of these patients also had Kartagener syndrome. Our findings suggest an association between AATD and bronchiectasis, independent of emphysema, and suggest that alpha-1 antitrypsin genotypes should also be examined in cases of bronchiectasis without emphysema to determine its etiology.