Pathophysiology of hereditary emphysema.

Abstract

Patients with decreased serum alpha1-antitrypsin were designated as severely deficient (7% to 15% of normal) or intermediately deficient (30% to 65% of normal) by quantitative radial immunodiffusion. All severely deficient patients were symptomatic and had severe emphysema. Among intermediately deficient patients emphysema was clinically evident only after age 50. Younger subjects had significant loss of lung elastic recoil and hyperinflation without expiratory flow obstruction. Older patients with an intermediate deficiency had abnormalities that were radiographically and physiologically identical to those of younger severely deficient patients. Postmortem examination of the lung of two patients with severe deficiency and one patient with intermediate deficiency showed extensive panlobular emphysema of the lower two thirds of the lungs, with relative sparing of the upper third. It is concluded that patients with intermediate alpha1-antitrypsin deficiency may develop emphysema identical to that found in severely deficient patients but at an older age.