Comparison of Blood Biocompatibility During Haemodialysis with Cuprophane and Polacrylonitrile Membranes

Abstract

Clotting within the dialyser is one of the most significant clinical parameters of biocompatibility. A study was designed to evaluate the biocompatibility of two different dialysis membranes (cuprophane and polyacrylonitrile) during therapy with conventional heparin. Transient leukopenia during cuprophane but not during polyacrylonitrile haemodialysis was observed, and elastase release using polyacryonitrile membranes was reduced (P less than 0.001). An elevation in F VIII:C activity during cuprophane haemodialysis has to be taken as an indication of endothelial disturbances. There was a significant (P less than 0.001) platelet activation (beta-thromboglobulin) and combined thrombin/plasmin generation using cuprophane membranes. This new synthetic polyacrylonitrile membrane inactivates the clotting in an extracorporeal system to a sufficient degree and allows a reduction in dosages of heparin. Platelet activation, platelet turnover, disturbances of endothelium, fibrinolysis activation, and granulocyte activation are reproducible parameters of a described interaction model. They also permit a comparison of different haemodialysis membranes.

Platelet GPIIb/IIIa Is Activated and Platelet-Leukocyte Coaggregates Formed in vivo during Hemodialysis

“…These findings would mean that the stimuli causing the degranulation of platelets persist longer than the stimuli causing the conformational activation of GPIIb/IIIa during hemodialysis. Platelet activation during hemodialysis may be due to many factors, including shear stress, contact activation and agonist activation [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11]. Further examination is still needed to elucidate the more precise mechanism of platelet activation during hemodialysis.…”

“…During hemodialysis, the contact of blood with the prosthetic devices and the interaction of blood and artificial membranes result in platelet activation and a decrease in platelet cell count [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11]. The degree of platelet activation depends on the flow design of the dialysis membrane used [1, 2], the composition and geometry of the dialysis membrane [3, 4, 5, 6, 7, 8, 9, 10], and on rheological factors derived from blood circulation [11].…”

“…The degree of platelet activation depends on the flow design of the dialysis membrane used [1, 2], the composition and geometry of the dialysis membrane [3, 4, 5, 6, 7, 8, 9, 10], and on rheological factors derived from blood circulation [11]. In association with platelet activation, GPIIb/IIIa (CD41/CD61) is converted from a resting form into an activated form, in which its ligand-binding sites are exposed [12, 13, 14].…”

“…While some studies have reported the advantage of some synthetic membranes over cellulosic membranes in terms of platelet activation and platelet-leukocyte coaggregate formation [3, 4, 5, 6, 7, 26, 28], others have shown no differences in this regard [8, 9, 10]. Moreover, the tests used to study platelet function in clinical settings have their own limitations [15].…”

Effect of Vitamin-E-Modified Dialysers on Dialyser Clotting, Erythropoietin and Heparin Dosage: A Comparative Crossover Study

“…Lipid peroxidation enhances hyperaggregability of platelets [3] that may aggravate dialyser clotting. Clotting within the dialyser is one of the most significant clinical parameters of biocompatibility [4]. Studies have shown that the use of vitamin-E-modified dialysis membranes is associated with a significant reduction in lipoperoxidation and therefore a decrease in oxidative damage compared to conventional membranes [5,6].…”