plasmapherese

Plasmapheresis, also known as therapeutic plasma exchange, is a medical procedure that removes plasma from the blood and replaces it with a substitute fluid. By removing plasma, it aims to reduce circulating pathogenic substances such as autoantibodies, immune complexes, cytokines, and certain toxins that contribute to disease activity in specific conditions.

The procedure uses centrifugation or membrane filtration to separate plasma from the blood’s cellular components. Blood is drawn through peripheral veins or a central venous catheter, plasma is separated and discarded or processed, and the remaining cellular elements are returned with a replacement fluid. Replacement fluids are typically 5% albumin or donor plasma, though other transfusion products may be used in certain situations. An anticoagulant such as citrate is commonly infused during the procedure to prevent clotting.

A typical session exchanges about 1 to 1.5 plasma volumes, roughly 40–60 mL per kilogram of body weight. Each treatment lasts about 1–2 hours, and courses are usually given daily or every other day for a defined period, depending on the underlying disease and response to therapy.

Indications for plasmapheresis include autoimmune and neurological disorders such as Guillain–Barré syndrome and chronic inflammatory demyelinating polyneuropathy, myasthenia gravis crisis, thrombotic thrombocytopenic purpura, rapidly progressive lupus nephritis, and other antibody-mediated diseases. It is also used in some hyperviscosity syndromes and certain poisonings or toxin-mediated conditions. Decisions about its use depend on the diagnosis, disease activity, and the balance of potential benefits and risks.

Risks include hypotension, catheter-related complications, bleeding, infection, electrolyte disturbances, and hypocalcemia due to citrate anticoagulation. The procedure requires specialized equipment and trained personnel.