Plasma Exchange

Posted by Elaine Moore Oct 13, 2007

Plasma exchange (plasmapheresis), is a procedure in which blood is removed and its components (red blood cells, platelets, and plasma) separated. The plasma is discarded while the blood cells and platelets are transfused into the patient along with a plasma substitute. Plasmapheresis is used in several autoimmune conditions to reduce immunoglobulins (antibodies and autoantibodies).

Plasma Exchange in Autoimmune Conditions

Plasma exchange is widely used for the treatment of idiopathic thrombocytopenic purpura (ITP), myasthenia gravis, Lambert-Eaton syndrome, Guillain-barre syndrome, and chronic dymyelinating polyneuropathy. Its effectiveness in other conditions, such as multiple sclerosis, polymyositis, systemic lupus, autoimmune hemolytic anemia, and dermatomyositis, is not as well established.

Plasma Exchange Procedure

Plasmapheresis can be performed on outpatients. The procedure takes several hours and may cause discomfort although it is not painful. The amount of blood withdrawn is much less than the amount taken from blood donors. The usual protocol involves 6 to 10 separate plasmapheresis procedures within a two-week period although this can vary.

Patients may sit in a reclining chair or lie in bed. A small thin tube or catheter is inserted into a vein, usually a vein in the crook of the arm (antecubital area). Another tube placed in the opposite hand or foot is used to transfuse the separated blood components.

Adverse Effects

The most common side effect is a drop in blood pressure. This can cause faintness, dizziness, coldness, sweating, or abdominal cramps. Anticoagulants administered with the transfused red blood cells can cause bleeding or tingling sensations. These reactions can lead to irregular heartbeat or seizures if untreated. Allergic reactions to the transfused donor plasma can also occur. Because normal protective antibodies are also reduced patients can have an increased risk of infection.

Resources:

McLeod BC, Evidence based therapeutic apharesis in autoimmune and other hemolytic anemias, Current Opinions in Hematology, November 2007;15(6):647-654.