Tissue Factor, Its Inhibitor, and the Thrombogenicity of Two New Synthetic Membranes

Background: The aim of the study was to compare the effect of new high-flux hemodialysis membranes made from polyacrylonitrile (AN69ST) and polysulfone (Helixone) on the plasma levels of tissue factor (TF) and tissue factor pathway inhibitor (TFPI) playing a key role in hemostasis. Established thrombogenicity markers were also determined. Methods: In a clinical prospective randomized study, 10 patients were examined using either membrane at the start and at minutes 15, 60, and 240 of hemodialysis. Results: Increases in the plasma TF levels reached significance at the end of hemodialysis with both membranes, with the Helixone also after 15 min. TFPI levels tended to rise significantly from minute 15 onward while not differing from baseline at the end of the procedure. Judging by the increase in thrombin–antithrombin III complexes, both membranes significantly activated coagulation at the end of hemodialysis. Platelet factor 4 levels, released during thrombocyte and endothelial stimulation, were elevated from the start of procedures. There were no significant differences between the AN69ST and the Helixone in any of the assessed markers. Conclusions: The AN69ST and Helixone membranes do not differ in their effects on TF and TFPI or even in established thrombogenicity markers.