Therapeutic Plasmapheresis Today

Abstract

In 1914, Abel, along with Rowentree and Turner, introduced the term “plasmapheresis” whose literal meaning is “subtraction”. The first “therapeutic plasmapheresis” was performed in 1952 in a patient with multiple myeloma; in 1963, patients with paraproteinemia were treated with plasmapheresis to reduce blood hyperviscosity, as described by Salomon and Fahey. During the course of time, more specific and selective techniques were gradually introduced, allowing the use of the treatment for new clinical indications (plasma exchange, CRYO apheresis, leukapheresis, thrombocytopheresis, lymphocyte apheresis, LDL apheresis). The current indications for plasmapheresis have been defined, and periodically re-established, by two scientific American associations, the American Association of Blood Banks (AABB) and the American Society of apheresis (ASFA), based on the available evidence of efficacy of this treatment in specific diseases. In 1993, a study group for therapeutic apheresis was created within the Italian Society of Nephrology, and was also aimed at developing new guidelines. The aim of therapeutic apheresis is to remove pathogenic substances. The use of techniques for selective removal allows a lesser elimination of non-pathological components, reducing the risk of infections, bleeding, and allergic reactions. However, although the therapeutic success is related to the amount of the pathological substances removed, it is likely that plasma also acts by modulating the patients' immune system. In fact, normal apheretic procedures would act directly on the immune system's components and mediators. Therapeutic apheresis is indicated during the course of immunological disorders including dermatological, hematological, oncological, dysmetabolic, neurological, and renal diseases, and is also used in an emergency setting as a technique for the detoxification of both endogenous and exogenous substances to avoid irreversible organ damage. Therapeutic plasmapheresis has undergone significant changes due to the development of the equipment and to the new indications. In fact, the technological innovation has introduced new methods that allow plasmapheresis to be more tolerable and less invasive. Hemofenix uses filtration through a membrane with an innovative system of nanofiltration, the ROSA filter. Hemofenix allows to perform the treatment with a single, small needle and with a greatly reduced extracorporeal volume of about 70 mL, thus reducing the risks for the patients, even in children. Additional advantages are represented by the low priming and short duration of the treatment; furthermore, the exchange of low volumes during the treatment allows not using plasma as replacement fluid, thus reducing the risk of infections and allergic reactions related to plasma exchange. Clinical trials should be performed to demonstrate the effectiveness of this method by comparing this therapy with the traditional apheretic one.