Clearance of fibrinogen and von Willebrand factor in serial double-filtration plasmapheresis.

Double filtration plasmapheresis (DFP) is a widely used and effective way to clear autoantibodies from plasma. It can, however, transiently alter the hemostatic system and cause a bleeding tendency in some patients. There is limited data on the consecutive effect of serial DFP on the hemostatic system, especially on fibrinogen and von Willebrand factor (vWF) levels. This study measured fibrinogen and vWF serially before and after each session of DFP in 8 patients who received one course of DFP treatment for 3 to 5 consecutive sessions on an alternate-day basis. In each session of DFP, the clearance rate of fibrinogen and vWF exceeded 63 and 45%, respectively. The final levels of fibrinogen and vWF after a full course of DFP were reduced to 14.3 and 51.2% of baseline level, respectively. No bleeding tendency was observed in any of the 34 DFP sessions. In conclusion, although an obvious decrease in fibrinogen level and the modest decrease in vWF were observed after an intensive course of DFP treatment, the low incidence of clinically important bleeding confirms the hemostasis-related safety of DFP. Copyright 2003 Wiley-Liss, Inc.