[Alpha 1-antiproteinase deficiency].

The dysbalance between proteolytic neutrophil elastase and its endogeneous inhibitor seems to be a pathogenetic key mechanism in the origin of pulmonary emphysema (elastase-antielastase hypothesis). This hypothesis is supported by the observation, that low serum levels of alpha 1-antitrypsin can be observed in smokers with premature pulmonary emphysema. alpha 1-proteinase inhibitor is an acute phase protein with known structural and moleculargenetic aspects, which is synthesized by the liver and reaches the lung by the circulation. Its role is the inactivation of excessive neutrophil elastase in the pulmonary parenchyma, which is liberated during inflammation and destroys elastin and other components of extra-cellular connective tissue matrix. This is an overview on epidemiology, clinical aspects, genetics and molecular biology of this particular disease which was described in 1963.