Prevalence of Alpha-1 Antitrypsin Deficiency in COPD Patients in Argentina. The DAAT.AR Study

Abstract

Introduction: Alpha-1 antitrypsin deficiency (AATD) is still underdiagnosed, despite the recommendation to determine AAT in patients with chronic obstructive pulmonary disease (COPD).

Objective: To estimate the prevalence of AATD in COPD patients adjusted according to the population of the COPD prevalence study in Argentina (EPOC.AR).

Material and methods: This was a multicenter prospective cross-sectional study of a population aged≥30 years of age diagnosed with COPD, involving AAT quantification in dry blood spot and subsequent genotyping in subjects with<1.5mg/dL AAT in dry blood spot (<80mg/dL in serum). AAT was defined as the detection of variants ZZ or SZ on genotyping. The EPOC.AR study population was used to calculate local adjusted prevalence.

Results: We included 3,254 patients (544 with AAT<80mg/dL) with a spirometric diagnosis of COPD. The prevalence of AATD in the total study population was 1.29% (95% CI 0.93-1.74), of which 0.92% (95% CI 0.62-1.31) were Pi*ZZ and 0.37% (95% CI 0.19-0.64) Pi*SZ. The adjusted prevalence of AATD in COPD patients≥40 years of age was 0.83% (95% CI 0.23-2.08). We found that AATD was negatively associated with age (OR 0.94; 95% CI 0.90-0.98; P=.006), smoking habit (OR 0.98; 95% CI 0.96-0.99; P=.009), and FEV₁% (OR 0.95; 95% CI 0.91-0.99; P=.015).

Conclusions: The prevalence of AATD in the adult population with COPD in Argentina is estimated to be 0.83%, which could represent 17,000 cases in our country.

Keywords: Alpha-1 antitrypsin deficiency; Argentina; Chronic obstructive pulmonary disease; DAAT.AR; Déficit de alfa-1 antitripsina; EPOC.AR; Enfermedad pulmonar obstructiva crónica; Prevalence; Prevalencia.