Experience in the treatment of myasthenia gravis with double filtration plasmapheresis

Myasthenia gravis (MG) is an autoimmune disease characterized by production of autoantibodies directly against acetylcholine receptors on postjunctional membranes. The treatment modalities of myasthenia gravis include cholinesterase inhibitors, surgical thymectomy, immunosuppressive treatment, and short-term immunotherapies, including plasmapheresis and intravenous immune globulin. Double filtration plasmapheresis (DFP) is a new technique of plasmapheresis. The aim of our study is to evaluate the effectiveness and complications of DFP in the treatment of MG.

From December, 1993 to August, 1998, a total of 33 patients with MG received 68 courses (total of 299 sessions) of DFP in our hospital. Plasmapheresis volume, drainage volume, treatment duration, heparin dose, and complications were recorded. In addition, clinical responses after DFP were also evaluated.

Only 4 courses (5.88%) of treatment were ineffective. Sixty-four courses (94.12%) of treatment lessened disease activity. The complications of DFP included 15 episodes of hypotension (5.01%), 2 of bradycardia (0.67%), 3 of chest pain (1.00%), 7 of dizziness (2.34%), 58 of high transmembranous pressure of plasma separator (19.40%), 3 of high secondary pressure of plasma fractionator (1.00%), 12 of hemolysis (4.01%), 2 of plasma separator clot (0.67%), 2 of plasma fractionator clot (0.67%), 3 of blood leakage (1.00%), and 1 of air embolism (0.33%). There was no mortality associated with the DFP procedure.

DFP is a safe, convenient, and time-saving therapy with rare severe complications in the treatment of MG. Our experience confirms its effectiveness when used in combination with drug therapy and thymectomy.