Plasma filtration on mediators of thrombotic microangiopathy:: An in vitro study

Objectives. Sepsis-induced thrombotic microangiopathy is successfully treated by plasma exchange therapy. However, certain putative mediators of thrombotic microangiopathy may not be removed by plasma filtration. Methods. We conducted an in vitro study to determine whether plasma filtration can remove ultra-large von Willebrand factor (ULvWF) multimers and other mediators. In separate experiments, human umbilical venous endothelial cell (HUVEC) supernatant enriched with ULvWF or human whole blood was passed through a therapeutic plasma exchange (TPE 2000, PRISMA) filter and samples were taken for measurement of ULvWF, vWF ristocetin cofactor vWF antigen and PAI-1. Results. The sieving coefficients for vWF and PAI-1 were above 0.9. The ULvWF was gradually eliminated, and nearly disappeared after four circulations. Conclusion. The TPE 2000 filter can directly remove potential mediators of sepsis-induced thrombotic microangiopathy.