Plasmapheresis

Plasmapheresis, or therapeutic plasma exchange (TPE), is a medical procedure in which patient plasma is removed and replaced with substitute fluids to eliminate disease-causing substances from the circulation. By lowering levels of autoantibodies, immune complexes, cryoglobulins, paraproteins, or certain toxins, it can alter the course of various disorders.

During the procedure, blood is drawn through a vein and processed by an apheresis device. Plasma is separated from cellular components by centrifugation or membrane filtration, discarded, and replaced with 5% albumin or donor plasma. The red cells and other formed elements are returned to the patient, along with replacement fluid. Exchange volumes typically equal 1 to 1.5 times the patient’s plasma volume and sessions are often performed daily or every other day for several treatments, depending on the condition and response. Anticoagulation is used during the procedure.

Indications include thrombotic microangiopathies such as thrombotic thrombocytopenic purpura; several autoimmune diseases where pathogenic plasma is implicated, including Guillain–Barré syndrome, CIDP, and myasthenia gravis in crisis; Goodpasture syndrome; antibody-mediated rejection in organ transplantation; hyperviscosity from monoclonal gammopathies; cryoglobulinemia; and certain poisonings or toxin exposures.

Risks include hypotension, citrate-induced hypocalcemia, infection, bleeding, allergic reactions to plasma products, electrolyte disturbances, and vascular access complications. Contraindications are hemodynamic instability or inability to tolerate anticoagulation, severe coagulopathy, or inability to obtain suitable vascular access.

Plasmapheresis can rapidly reduce circulating pathogenic factors and serves as a temporizing or bridging therapy in many conditions, often as part of a broader treatment plan.