Alpha-1 deficiency in severe asthma patients.

Alpha-1 antitrypsin (AAT) deficiency, an autosomal co-dominant condition, decreases protein concentration and activity at both serum and tissue levels. Few studies investigated whether the type of SERPINA1 gene phenotype in patients with severe asthma can influence symptoms and disease control during follow-up.To assess whether the presence of a non-MM genotype of SERPINA1 in patients with severe asthma is associated with disease control, systemic and airway inflammation, lung function and comorbidities prevalence compared to severe asthma patients with a homozygous genotype (MM).Asthmatic patients belonging to Global Initiative for Asthma (GINA) step 5 were retrospectively analysed in an Italian reference asthma clinic. We collected clinical, biological and functional variables at baseline and for the three following years.Out of 73 patients enrolled, 14 (19.18%) were non-MM and 59 (80.8%) were MM. Asthmatics with non-MM genotype had lower serum AAT concentration (P = 0.004) and higher emphysema prevalence than the MM group (P = 0.003) at baseline. During follow up, only MM patients showed a significant improvement of both ACQ-6 score (P < 0.0001) and eosinophilic systemic inflammation (P < 0.0001).Our findings emphasise the importance of a screening for AAT deficiency in severe asthma, as alleles mutation may influence patient's follow-up..