Prevalence of genetic mutations in alpha-1 antitrypsin deficiency (aatd) in patients with chronic obstructive pulmonary disease in Colombia

Abstract

Background: Alpha-1 antitrypsin deficiency (AATD) is an underrecognized genetic disorder associated mainly with pulmonary emphysema and Chronic Obstructive Pulmonary Disease (COPD). All individuals with COPD regardless of age or ethnicity should be tested for AATD, but in Colombia its prevalence in unknown. Main objective: To determine the prevalence of the genetic mutations, present in AATD in adult patients with COPD in Colombia, using a genotyping test on cells from the oral mucosa. Methods: This was a multicentre, observational, cross-sectional study which included adult patients attending seven COPD care centres in Colombia. Demographic data, medical history, including history of exposure to smoking and biomass smoke, most recent spirometry, pharmacological and non-pharmacological treatment received, serum AAT levels, and mutations detected by the genotyping test were recorded for all the recruited patients. For the comparison of variables between the groups with and without mutation, we used the X2 test for the qualitative variables and the Student’s t-test or Mann-Whitney U test according to their distribution. Main findings: We collected a sample of 1,107 patients, the median age was 73.8 years (87.6–79.9). Mutations were documented in 144 patients (13.01%), the majority had the M/S mutation (78.50%), followed by M/Z (9.72%). One patient had a ZZ mutation and two patients had null alleles. In total, 23 patients had mutations associated with serum AAT deficiency (levels below 60 mg/dl). Conclusions: Genetic mutations were documented in 13.01% of patients with COPD in Colombia and 2.07% were AATD-related, showing that there is a significant number of underdiagnosed patients.