Effect of α 1 antitrypsin deficiency on lung volume decline in severe asthmatic patients undergoing biologic therapy

In that population, it should be routinely explored to prompt specific interventions including smoking cessation, optimization of lung function monitoring, and tailored treatment. α1 antitrypsin (AAT) is a polymorphic protein with more than 100 variants, labeled A through Z according to the electrophoretic migration position compared with the normal M variant.1 An autosomal codominant disorder caused by mutations of the SERPINA1 gene, AAT deficiency (AATD) may produce variable clinical manifestations including lung emphysema and liver cirrhosis, depending on the concentration of functional AAT in blood and tissues. α1 Antitrypsin serum level of 1.1 g/L or higher can be considered evidence of normal status.1 If lower, both phenotyping and genotyping analysis are required.1 α1 Antitrypsin deficiency has been associated with chronic obstructive pulmonary disease (COPD) and bronchiectasis.2 Individuals with severe AATD usually experience a decline in accelerated forced expiratory volume in 1 second (FEV1) of 47 to 70 mL/y, depending on smoking habits.3 In severe asthmatic patients, AATD prevalence has not been clearly defined. Whereas an accelerated lung function decline in asthmatics with concomitant AATD was reported,8 other authors did not confirm different clinical and/or pulmonary patterns according to AAT status.9 Moreover, the same study showed that 22% of asthmatic patients with perennial allergic sensitization had at least one mutated allele. [...]in this population, AATD should be routinely explored as early as possible, and a correct diagnosis could prompt specific interventions including smoking cessation, optimization of lung function monitoring, and tailored treatment. Variable Total cohort Current or former smokers Nonsmokers Without AAD With AAD P Without AAD With AAD P Patients, n 143 20 3 113 7 Age, y 52.2 ± 12.2 56.9 ± 9.3 54.3 ± 8.3 .651 51.6 ± 12.5 47.7 ± 14 .428 Female, n (%) 86 (60) 6 (30) 1 (33) >.999 73 (65) 6 (86) .420 Body mass index, kg/m2 25.1 (5) 26.7 (5) 23.9 (NA) .144 25 (5.1) 23.2 (5.1) .117 Presence of atopy, n (%) 104 (73) 16 (80) 3 (100) >.999 82 (73) 3 (43) .192 Presence of nasal polyps, n (%) 78 (54) 9 (45) 2 (67) .590 61 (54) 6 (86) .132 FEV1, L 2.22 ± 0.72 2.26 ± 0.80 2.39 ± 0.50 .794 2.21 ± 0.73 2.10 ± 0.41 .709 FEV1, % of predicted 73.8 ± 19.8 68 ± 20 85.3 ± 23.4 .186 74.1 ± 19.4 80 ± 23.6 .443 FVC, L 3.20 ± 0.91 3.27 ± 1.01 2.92 ± 0.73 .571 3.22 ± 0.92 2.96 ± 0.49 .469 FVC, % of predicted 86.2 ± 17.9 77.3 ± 20.2 83.7