Coagulation abnormalities in serial double-filtration plasmapheresis.

Intensive plasma exchange can transiently alter the hemostatic system. However, the effect of serial double filtration plasmapheresis (DFP) on the hemostatic system has not been adequately described. In this study, we sought to characterize the hemostatic effects of DFP in 32 myasthenia gravis patients who received one course of DFP treatment for five consecutive sessions within 10 days. Platelet count, prothrombin time (PT), partial thromboplastin time (PTT), and serum levels of albumin, globulin, cholesterol, and fibrinogen were measured before and after the course of DFP. Patients were divided into mild hypofibrinogenemia (MH) and severe hypofibrinogenemia (SH) groups based on post-plasmapheresis residual levels of fibrinogen above or below 70 mg/dl. The baseline fibrinogen level was significantly lower in the SH group (P < 0.01). After five sessions of DFP, the fibrinogen level was reduced to below 70 mg/dl in 14 patients (44%). The percentage of excessive prolongation of PT or PTT was significantly higher in the SH group. The SH group also had higher reduction rates of globulin and cholesterol (P < 0.05). Oozing in the punctured site of the central venous catheter occurred in 6 out of 26 patients, with four cases in the MH group and two in the SH group. There was no difference in the overall incidence of bleeding complications between the two groups. Only one episode of clinically overt bleeding occurred during the study after a large-bore femoral catheter was removed soon after the patient had received five consecutive daily treatments. The bleeding stopped after transfusion of 6 units of fresh frozen plasma. In conclusion, despite the obvious reduction of fibrinogen level and the modest decrease in platelet count after an intensive course of DFP treatment, the low incidence of clinically overt bleeding confirmed the safety of DFP.