Asthma and allergy in alpha-1 antitrypsin deficiency

Summary

This study was designed to determine the prevalence of asthma and atopy, in a large group of subjects with alpha-1 antitrypsin deficiency (AATD) participating in the Alpha-1 Foundation Research Registry. A survey was mailed to all Registry participants $(N=2418)$ and results were collated by AATD phenotype. Participants with PiZZ deficiency were compared to PiMZ and other phenotypes by nonparametric statistics. Responses were collected from 757 participants (31%). Overall 44.6% $(N=338)$ reported MD diagnosed asthma. Wheezing was reported in 76% with respiratory infections, activity and exposure to dusts, fumes, and allergens as common triggers. Across the three groups reported asthma with a history of allergies was reported from 20% to 25%. Wheezing symptoms were significantly less common in the PiMZ group compared with other groups. Of those reporting asthma, 83% of the PiZZ group $(n=192)$ also reported another chronic obstructive pulmonary disease (COPD) diagnosis compared to 48% of the PiMZ group $(n=24)$. Asthma as the only reported diagnosis was three times more prevalent in the PiMZ group compared with the PiZZ group. Although asthma diagnosis is imprecise in the presence of COPD, the high prevalence of wheezing to allergen and irritant exposures with symptoms of atopy suggests that asthma is common in AATD but usually associated with COPD. Those with AATD who are susceptible to asthma require allergy evaluation and aggressive anti-inflammatory strategies as part of their management.