During<unk> , blood (which consists of blood cells and a clear liquid called plasma) is initially taken out of the body through a needle or previously implanted catheter. Plasma is then removed from the blood by a cell separator. Three procedures are commonly used to separate the plasma from the blood cells, with each method having its own advantages and disadvantages: * 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. * Continuous flow centrifugation: Two venous lines are used. This method requires slightly less blood volume out of the body at any one time, as it is able to continuously spin out plasma. * Plasma filtration: Two venous lines are used. The plasma is filtered using standard hemodialysis equipment. This continuous process requires that less than 100 ml of blood be outside the body at one time. 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<unk> tient in traditional<unk> . Rarely, other replacement fluids, such as hydroxyethyl starch, may be used in individuals who object to blood transfusion but these are rarely used due to severe side-effects. Medication to keep the blood from clotting (an anticoagulant) is given to the<unk> tient during the procedure.<unk>  is used as a therapy in<unk> rticular diseases. It is an uncommon treatment in the United States, but it is more common in Europe and<unk> rticularly Japan. An important use of<unk>  is in the therapy of autoimmune disorders, where the rapid removal of disease-causing autoantibodies from the circulation is required in addition to other medical therapy. It is important to note that plasma exchange therapy in and of itself is useful to temper the disease process, while simultaneous medical and immunosuppressive therapy is required for long-term management. Plasma exchange offers the quickest short-term answer to removing harmful autoantibodies; however, the production of autoantibodies by the immune system must also be suppressed, usually by the use of medications such as cyclophosphamide, cyclosporine, mycophenolate mofetil, prednisone, rituximab, or a mixture of these. Other uses are the removal of blood proteins where these are overly abundant and cause hyperviscosity syndrome. Examples of diseases that have been treated with<unk>  * Acute disseminated encephalomyelitis (ADEM) * Antiphospholipid antibody syndrome (APS or APLS) * Behcet syndrome * Chronic inflammatory demyelinating polyneuropathy * Goodpasture's syndrome * Granulomatosis with polyangiitis * Graves' disease in infants and neonates * Guillain–Barré syndrome * HELLP syndrome * HIV-related neuropathy * Hyperviscosity syndromes: * Cryoglobulinemia *<unk> raproteinemia * Waldenström macroglobulinemia * Idiopathic pulmonary fibrosis * Lambert-Eaton syndrome * Microscopic polyangiitis * Miller Fisher syndrome * Multiple sclerosis * Myasthenia gravis * Neuromyelitis optica * Opsoclonus myoclonus syndrome *<unk> NDAS syndrome (experimental, unproven) * Pemphigus vulgaris * Recurrent focal and segmental glomerulosclerosis in the transplanted kidney * Refsum disease * Rhabdomyolysis * Systemic sclerosis (scleroderma) * Thrombotic thrombocytopenic purpura (TTP) / hemolytic uremic syndrome * Toxic epidermal necrolysis (TEN) * Transverse myelitis Complications of<unk>  therapy Though<unk>  is helpful in certain medical conditions, like any other therapy, there are potential risks and complications. Insertion of a rather large intravenous catheter can lead to bleeding, lung puncture (depending on the site of catheter insertion), and, if the catheter is left in too long, it can get infected. Aside from placing the catheter, the procedure itself has complications. When<unk> tient blood is outside of the body<unk> ssing through the<unk>  machine, the blood has a tendency to clot. To reduce this tendency, in one common protocol, sodium citrate is infused while the blood is running through the circuit. Citrate binds to calcium in the blood, calcium being essential for blood to clot. Citrate is very effective in preventing blood from clotting; however, its use can lead to life-threateningly low calcium levels. This can be detected using the Chvostek's sign or Trousseau's sign. To prevent this complication, calcium is infused intravenously while the<unk> tient is undergoing the<unk> ; in addition, calcium supplementation by mouth may also be given. Other complications include: * Bleeding or hematoma from needle placement * Hypotension * Potential exposure to blood products, with risk of transfusion reactions or transfusion transmitted diseases * Suppression of the<unk> tient's immune system
Plasmapheresis
Autosplenectomy
Leukapheresis
Apheresis
Splenectomy
Exchange transfusion
Erythrocytapheresis
Photopheresis