Abstract
We previously reported 24 patients with AAT deficiency (AATD) and found them not different from non-AATD subject in terms of lung function, AER and CAT scores. We aimed to expand our observations to include emphysema scores derived from thoracic CT scans. 23 genotyped subjects with serum AAT levels <1.15g/L (2 MS, 3 MZ, 2 SS, 1 ZZ, 15 MM) and 23 ≥1.15g/L had thoracic CT scans available. MM subjects were subdivided into serum AAT levels ≥ and < 0.91g/L as the MM<0.91 group may have null or rare alleles and require SERPINA1 gene sequencing. Lung emphysema was determined using a threshold of -950 HU to define the low attenuation area percentage (LAA% (-950 HU)) and measured with Airway Inspector (www.airwayinspector.org). Demographics, physiology, AERs, CAT scores and LAA% (-950 HU) did not differ between groups. LAA% correlated with FEV1 (r=-0.42, p<0.01), DLco (r=-0.50, p<0.01) and FEV1/FVC (r=-0.73, p<10-8, Figure 1) but not AER (r=0.08, p=0.61) or CAT scores (r=-0.02, p=0.89).
In this small group of COPD patients emphysema scores did not differ between those with and without AATD and correlated with the FEV1, FEV1/FVC and DLco. These results support the notion that airway-parenchymal interdependence is an important determinant of airflow obstruction in both AATD and non-AATD COPD patients.
- © 2013 ERS
