ABSTRACT
Apheresis is the process in which a specific component of blood (either plasma, a plasma component, white cells, platelets, or red cells) is separated and removed with the remainder of the blood returned to the patient (often in combination with some type of replacement fluid). Donor apheresis is used for the collection of specific blood cells or plasma components from blood donors, resulting in a much more effective use of limited blood-based resources. Donor apheresis developed during World War II as a means for increasing the supply of critically needed plasma, and clinical trials in 1944 demonstrated that it was possible to safely collect donations of a unit of plasma (∼300 ml) on a weekly basis if the cellular components of blood were returned to the donor. Therapeutic apheresis is used for the treatment of a variety of diseases and disorders characterized by the presence of abnormal proteins or blood cells in the circulation which are believed to be involved in the progression of that particular condition. Therapeutic apheresis thus has its roots in the ancient practice of bloodletting, which was used extensively well into the 19th century to remove “bad humors” from the patient’s body, thereby restoring the proper balance between the “blood, yellow bile, black bile, and phlegm.”
