The level of granulocyte elastase (ELP) in children suffering from inflammatory diseases.

In order to study on the elastolysis and fibrinolysis in inflammatory process, the level of granulocyte elastase (ELP) was assayed in inflammatory diseases. The assay was carried out in children suffering from inflammatory diseases such as Kawasaki disease (MCLS), pneumonia, allergic purpura and others.ELP was extracted from granulocytes by 2mol/l KSCN and measured by using the artificial substrate, Suc-Ala-Tyr-Leu-Val-pNA. The biological activity was expressed as amidolytic activity per cell. The ELP activity of normal newborn babies was 9.0±3.1 nU/cell and it increased by age, attaining to the level of 16.1±5.8 nU/cell of normal adults. In MCLS, pneumonia and aseptic meningitis, the level of ELP decreased during the 2nd and 3rd weeks of illness, and it returned to the normal range up to the 4th or 5th week. On the other hand, the level of ELP was not reduced in upper respiratory diseases in which the inflammation was moderate. In allergic purpura, the level of ELP increased and returned to the normal range after the 5th week. Although the causes of the decreased level of ELP in inflammatory diseases are not clear, it can be suspected that ELP is released from granulocytes and consumed during inflammatory process.