RT Journal Article SR Electronic T1 Exploring the relationship between alpha-1-antitrypsin deficiency and persistent airflow limitation in severe asthma JF European Respiratory Journal JO Eur Respir J FD European Respiratory Society SP PA4465 DO 10.1183/1393003.congress-2017.PA4465 VO 50 IS suppl 61 A1 Guillermo Menga A1 Daniel Colodenco A1 Magdalena Mercuri Guillemi A1 Luciana Montoto Piazza A1 Juan Rodríguez Moncalvo A1 Martín Fernández YR 2017 UL http://erj.ersjournals.com/content/50/suppl_61/PA4465.abstract AB Background: Persistent airflow limitation is common among patients with severe asthma, but its pathogenesis has not been fully clarified. Severe alpha-1-antitrypsin deficiency (AATD) is a risk factor for chronic airflow limitation and emphysema, and partially deficient phenotypes have been associated with an accelerated decline in lung function.Aims: To estimate frequency of AATD in patients with persistent airflow limitation in severe asthma.Methods: 207 patients with severe asthma and persistent airflow limitation (FEV1 <75% and reduced FEV1/FVC ratio) were included between 2013 and 2016.All patients underwent determination of serum AAT levels by nephelometry. In those patients with serum levels under 120 mg/dL an allele specific genotyping assay was performed to detect the most prevalent variants (Z and S).Statistical analysis was made with PAWS Statistics 18 © software.Results: We found female predominance (64.2%), mean age: 56 years (range 23-70), 14.5% of active smokers, Mean alpha-1 antitrypsin was 137 mg/dL. Genotyping assay was made in 20.2% samples that were under cut-off. Deficient patients MZ=3 (1.45%), SS=1 (0.49%), and MS=12 (5.79%).Conclusions: Prevalence of AATD in patients with severe asthma and airflow limitation is low. Routine assessment of AATD is not supported by this data therefore further studies are needed.