pheresis

pheresis A procedure in which the blood is filtered and separated, and a portion is retained, with the remainder being returned to the individual. There are various types of pheresis. For example, in leukapheresis, the leukocytes (white blood cells) are removed; in plateletpheresis, the thrombocytes (blood platelets) are removed; and in plasmapheresis, the liquid part of the blood (the plasma) is removed. See also plasmapheresis.