Plasmapheresis removes antibodies from the circulation, producing short-term clinical improvements. This is done by a procedure that usually entails five exchange treatments of 3 to 4 liters each, carried out over a two-week period. It is used primarily to stabilize the condition of patients in myasthenic crisis or for the short-term treatment of patients undergoing thymectomy.
Improvement correlates roughly with reduction in the anti-acetylcholine receptor antibody titers.
Unfortunately, effects are temporary, lasting only weeks. For those rare cases that other methods of treatment do not work, plasmapheresis can be used as a long-term therapy. Some negative aspects of the plasmapherisis process are problems with venous access, risk of infection of the indwelling catheter, hypotension, and pulmonary embolism. It produces rapid improvement to help patienst through a difficult period of myasthenic weakness. An extraordinary benefit of this process is that it does not require special equipment, and the usual dose is small, only 400 mg per kilogram per day for five successive days.