Therapeutic Plasma Exchange

Therapeutic plasma exchange (TPE) is a type of apheresis procedure during which a patient’s plasma is removed and replaced with either albumin or donor plasma. The goal of TPE is to remove pathologic substances present in a patient’s plasma to improve the underlying condition. For some diseases, both the removal of the pathologic substance and the replacement fluid (with normal proteins/substances) likely contribute to the benefit from TPE. Pathologic substances that are removed include autoantibodies, paraneoplastic antibodies, immune complexes, lipoproteins, and cryoglobulins. Substances that are primarily in the intravascular system (i.e., proteins that are bound to plasma and have low volume of distribution) are most effectively remove. TPE can be performed either by centrifugation or by membrane filtration. In membrane filtration, plasma can only be separated, and components removed by size, while with centrifugation, plasma can be separated, and blood components further fractionated by density (specific gravity). TPE is most commonly performed by centrifugation. The purpose of this chapter is to discuss the basics of TPE and review considerations for the patient undergoing TPE.