Prevalence of genetic mutations in Alpha-1 antitrypsin in patients with difficult-to-treat asthma in Colombia

BACKGROUND: Alpha-1 antitrypsin (AAT) is a medium-sized globular glycoprotein distributed in serum and tissues. In the lungs, it inhibits serine proteases and has anti-inflammatory properties in different types of cells, protecting lung tissue from damage. Mutations in the SERPINA1 gene that codes for AAT are related to asthma and chronic obstructive pulmonary disease. In Colombia, there are no published data on the prevalence of alpha-1 antitrypsin deficiency (AATD) in adult patients with difficult-to-manage asthma. ​This study aims to determine the prevalence of genetic mutations related to AAT in adult patients with difficult-to-treat asthma in Colombia. METHODS: This prospective, multicenter, cross-sectional study included adult patients with difficult-to-treat asthma in five asthma care centers in Colombia. Informed consent was obtained, and gingival mucosa was sampled for genetic diagnosis of AATD using the A1AT Genotyping Test. Data analysis was performed using the Chi2 test, Student's t-test, and Mann-Whitney test for group comparison. RESULTS: A total of 449 adult patients with difficult-to-treat asthma were included with a mean age of 56.1 ± 14.9 years; 73.1% (N = 328) were women; and 89.1% were using high-dose inhaled corticosteroid / long-acting B2 agonists. Mutations in the AAT gene were found in 12.5% (N = 56) of patients. Of these, 85.7% had the M/S genotype, 10.7% the M/Z genotype, 1.8% the M/I genotype, and 1.8% the S/S genotype. CONCLUSIONS: The study identified a prevalence of AAT mutations in 12.5% of adult patients with difficult-to-treat asthma in Colombia made up of four genotypes: M/S, M/Z, M/I and S/S.