The Distribution of Alpha-1 Antitrypsin Genotypes Between Patients with COPD/Emphysema, Asthma and Bronchiectasis

Martina Veith,1 Julia Tüffers,1 Erika Peychev,1 Andreas Klemmer,1 Viktor Kotke,1 Sabina Janciauskiene,2 Susanne Wilhelm,1 Robert Bals,3 Andreas Rembert Koczulla,4 Claus Franz Vogelmeier,1 Timm Greulich1 1Department of Medicine, Pulmonary and Critical Care Medicine, University Medical Center Giessen and Marburg, Member of the German Center for Lung Research, Marburg, Germany; 2Clinic for Pneumology, German Center for Lung Research (DZL), Medical University Hannover, Hannover, Germany; 3Department of Internal Medicine V, Pulmonology, Allergology, Respiratory and Intensive Care Medicine, Saarland Hospital, Homburg/Saar, Germany; 4Institute for Pulmonary Rehabilitation Research, Schoen Klinik Berchtesgadener Land, Teaching Hospital of Philipps-University of Marburg, Marburg, GermanyCorrespondence: Martina VeithDepartment of Medicine, Pulmonary and Critical Care Medicine, University Medical Center Giessen and Marburg, Member of the German Center for Lung Research, Marburg, GermanyTel +4964215864723Fax +496421586370Email veithm@staff.uni-marburg.dePurpose: Alpha-1-antitrypsin deficiency (AATD) is a rare hereditary condition characterized by low circulating levels of alpha-1antitrypsin (AAT). While the association between AATD and COPD/emphysema is undisputed, the association between AATD and asthma or bronchiectasis is still a matter of debate.Aims and Objectives: Our study aimed to investigate the distribution of AAT genotypes between patients with COPD/emphysema, asthma and bronchiectasis. To back up the diagnostic labels, we described symptoms associated with the diagnosis.Methods: Between September 2003 and March 2020, 29,465 testing kits (AlphaKit®) were analyzed in the AAT laboratory, University of Marburg, Germany. The diagnosis of AATD has been made based on the measurements of AAT serum levels, followed by genotyping, phenotyping or whole gene sequencing depending on the availability and/or the need for more detailed interpretation of the results. The respiratory symptoms were recorded as well.Results: Regarding the distribution of the wild type allele M and the most frequent mutations S (E264V) and Z (E342K), no significant differences could be found between COPD/emphysema [Pi*MM (58.24%); Pi*SZ (2.49%); Pi*ZZ (9.12%)] and bronchiectasis [Pi*MM (59.30%) Pi*SZ (2.81%); Pi*ZZ (7.02%)]. When COPD/emphysema and bronchiectasis were recorded in the same patient, the rate of Pi* ZZ (14.78%) mutations was even higher. Asthma patients exhibited significantly less deficient genotypes [Pi*MM (54.81%); Pi*SZ (2%); Pi*ZZ (2.77%)] than two other groups. Associated respiratory symptoms confirmed the diagnosis.Conclusion: COPD/emphysema and bronchiectasis, but not asthma patients, exhibit higher frequency of AATD genotypes. Our data suggest that AATD testing should be offered to patients with COPD/emphysema and bronchiectasis.Keywords: SERPINA1, alpha-1-antitrypsin deficiency, bronchiectasis, asthma, diagnosis