Pathophysiological effects of a limulus amoebocyte-lysate-positive substance during haemodialysis.

The washing solution of a dialyser was collected after recirculation of pyrogen-free water through the blood compartment, and the amount of limulus amoebocyte lysate-(LAL)-positive material was measured. Our study shows that the amount of LAL-positive substance on the cuprophane membrane of DIP-02-02 dialyser (USSR) is 5 times greater than in the case of cuprophane membrane of D2 hollow-fibre dialyser (Fresenius). There appears to be an acute increase (0.1 ng/ml) followed by a decline to normal values of LAL-positive substance concentration in the blood of patients in the first hour of haemodialysis using a DIP-02-02 dialyser. We conjecture that the cause of monocyte activation during haemodialysis is the LAL-positive material of the dialyser membrane, which in turn may induce the activation of lipid peroxidation and the increase of prostaglandin E production. However, it is not possible to exclude the likelihood that the origin of endotoxin-like LAL-positive substances lies in the dialysate.