plasmapheresis - Description, Indication

The circulation of whole blood outside the body, during which centrifugal force separates the cellular component and plasma, which is discarded and replaced by fresh plasma or plasma albumin. The purpose is to remove a damaging plasma component such as an abnormal antibody.

Plasmapheresis (from the Greek plasma, something molded, and apheresis, taking away) is the removal, treatment, and return of (components of) blood plasma from blood circulation.

Description

During plasmapheresis, blood is initially taken out of the body through a needle or previously implanted catheter. Three procedures are commonly used to separate the plasma from the blood:

Discontinuous flow centrifugation - One venous catheter line is required. Typically, a 300 ml batch of blood is removed at a time and centrifuged to separate plasma from blood cells. After plasma separation, the blood cells are returned to the person undergoing treatment, while the plasma, which contains the antibodies, is first treated and then returned to the patient in traditional plasmapheresis. (In plasma exchange, the removed plasma is discarded and the patient receives replacement donor plasma or saline with added proteins.) Medication to keep the blood from clotting (an anticoagulant) is generally given to the patient during the procedure.

Indication

An important use of plasmapheresis is in the therapy of autoimmune disorders, where the rapid removal of disease causing autoantibodies from the circulation is required in addition to slower medical therapy.

Other uses are the removal of blood proteins where these are overly abundant and cause hyperviscosity syndrome.

Examples of diseases that can be treated with plasmapheresis:

Guillain-Barré syndrome Chronic inflammatory demyelinating polyneuropathy Goodpasture's syndrome Hyperviscosity syndromes: Cryoglobulinemia Paraproteinemia Waldenström macroglobulinemia Myasthenia gravis Thrombotic thrombocytopenic purpura (TTP) Wegener's granulomatosis Lambert-Eaton Syndrome