Patients with alpha-1 antitrypsin deficiency (AATD) should undergo routine screening for potential bronchiectasis, as the prevalence is higher than expected and it may require a different treatment strategy.
These results are according to an initial report of the ongoing international, multicenter, observational European Alpha1 Research Collaboration (EARCO) study published in the Orphanet Journal of Rare Diseases.
The recently established EARCO International Registry—a phenotyping database of patients with AATD that is sponsored by the European Respiratory Society—allows for the estimation of bronchiectasis prevalence among individuals with AATD in an effort to better understand the impact, nature, and management of the disorder.
The researchers sought to determine patient characteristics among individuals with AATD and bronchiectasis. The current publication presents the initial findings from EARCO through December 2021. An analysis was conducted to examine radiologic evidence of both bronchiectasis and emphysema, along with baseline demographic characteristics of individuals with AATD and either or both of the pulmonary conditions.
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In EARCO, individuals older than18 years of age with AATD provided written informed consent for the collection of their clinical data during routine examinations at secondary care sites located in Belgium, Czech Republic, Croatia, Estonia, Italy, The Netherlands, Poland, Portugal, Romania, Spain, Sweden, Switzerland, Turkey, and the United Kingdom.
Participants with confirmed AATD, which was defined by serum AAT levels less than 50 mg/dL and/or the proteinase inhibitor ZZ (PiZZ) genotype, were eligible for study inclusion. The database was searched for all patients with a PiZZ genotype who had undergone a computed tomography (CT) densitometry scan. All patients were divided into 1 of 4 groups:
- Normal CT scan
- Evidence of emphysema alone on CT scan
- Evidence of bronchiectasis alone on CT scan
- Evidence of both emphysema and bronchiectasis on CT scan
Baseline CT scan data were used to compare the type and prevalence of bronchiectasis observed in those with PiZZ both with and without CT-verified emphysema.
Among the 860 individuals recruited to the EARCO registry through December 2021, 505 patients had a confirmed PiZZ genotype, with 82.8% (418 of 505) of them having a reported CT scan.
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Overall, 18.4% (77 of 418) of participants had a normal CT scan and 9.1% (38 of 418) of individuals had bronchiectasis alone. The patients in these 2 groups were primarily female never-smokers with pulmonary function in the normal range. The remaining 72.5% (303 of 418) of participants in whom emphysema was observed on their CT scan were described as follows:
- Lower zone distribution: 39.6%
- Upper zone distribution: 21.8%
- Widespread distribution: 38.6%
Overall, 27.0% (113 of 418) of participants with a PiZZ genotype reported bronchiectasis associated with emphysema.
Screening for AATD “should become a routine part of assessment in patients with bronchiectasis, and become a feature of indepth future clinical study and management,” the researchers explained. “In particular this should include microbiology [of] the airways inflammation compared with non-deficient chronic obstructive pulmonary disease, as well as the impact on progression and health status and the need for, and effect of antiproteinase therapy,” they concluded.
Stockley RA, Pye A, De Soyza J, Turner AM, Miravitlles M; EARCO study investigators. The prevalence of bronchiectasis in patients with alpha-1 antitrypsin deficiency: initial report of EARCO. Orphanet J Rare Dis. Pub;lished online August 12, 2023. doi:10.1186/s13023-023-02830-2