Convective gas mixing, airway dimensions and lung function parameters in patients homo- or heterozygote for hereditary alpha1-antitrypsin deficiency

Abstract

Informations about convective gas transport and airway morphometry as a function of volumetric lung depth (V(LD)) can be evaluated by means of two methods based on aerosol inhalation and determination of aerosol pulse parameters (APP) and effective airway dimensions (EAD). APP, EAD and conventional pulmonary function tests (PFT) were measured in patients homo- and heterozygote for alpha1-antitrypsin (alpha1-AT) deficiency. Thirteen homozygote subjects (ZZ allele), 21 heterozygote subjects (MZ allele) and 20 healthy controls were included. Anthropometric data were similar in all groups. APP but not PFT and EAD showed slight significant differences between controls and heterozygotes. However, PFT, APP and EAD from ZZ-homozygotes were strongly different from those of the other groups. Differences were also observed for APP between control smokers and nonsmokers and for APP, PFT and EAD between control nonsmokers and heterozygote smokers but not between heterozygote smokers and heterozygote nonsmokers and control nonsmokers and heterozygote nonsmokers, respectively. The data suggest that lung emphysema causes variations of pulmonary convective gas mixing detectable by measurement of APP which obviously precede variations of PFT. Our data further suggest that heterozygotes are not automatically at risk for the development of lung emphysema. Therefore we also regarded the results with request to individual smoking habits and found an increased risk in heterozygote smokers when compared to control nonsmokers.