Plasmapheresis (from the Greek πλάσμα - plasma, something molded, and ἀφαίρεσις - aphairesis, taking away) is the removal, treatment, and return of (components of) blood plasma from blood circulation. It is thus an extracorporeal therapy (a medical procedure which is performed outside the body). The method can also be used to collect plasma for further manufacturing into a variety of medications. The procedure is used to treat a variety of disorders, including those of the immune system, such as myasthenia gravis, Guillain-Barré syndrome, lupus, and thrombotic thrombocytopenic purpura...