Influence of haemodialysis membranes on the release of granulocyte elastase.

The advantages of multiparameter assessment in the evaluation of the blood compatibility of biomaterials underline the importance of investigating possible relevant parameters. In this respect, a study has been made of granulocyte elastase to establish the influence of haemodialysis membranes on the release of this serine proteinase. Plasma levels of granulocyte elastase were determined as a complex with its natural inhibiter, alpha 1-proteinase. This elastase - alpha 1 proteinase (E- alpha 1 Pi) inhibitor complex was measured by a highly sensitive enzyme-linked immunoassay. The membranes evaluated were Cuprophan (15-11, Travenol) and polysulphone (F40, Fresenius). Samples were taken from patients undergoing maintenance haemodialysis, before the start of dialysis, after 15 and 90 minutes and again at the end of dialysis (4 h). This investigation clearly demonstrates the different response of the dialysers, and on correcting for surface area, the end-dialysis level of E-alpha 1 Pi remained significantly greater for the Cuprophan membrane. The results support the view that the release of granulocyte elastase is a relevant parameter for inclusion in membrane compatibility assessment.