Enzyme-linked immunoassay for human granulocyte elastase in complex with alpha 1-proteinase inhibitor.

Granulocyte elastase in complex with its main inhibitor in plasma, i.e. alpha 1-proteinase inhibitor, was quantitatively determined by incubating the sample with solid-phase fixed antibodies against elastase first and reacting then with alkaline phosphatase-labelled antibodies against alpha 1-proteinase inhibitor. In normal plasma a level of 97.5 +/- 25.8 micrograms elastase/1 (mean +/- s.d., n = 43) was found, whereas moderately to markedly increased plasma concentrations were demonstrated in a variety of patients with inflammatory diseases like septicemia or rheumatoid arthritis.