These autoantibodies are created by a mix-up in the body's immune system. A physician will decide if it is desirable to remove a large quantity of the autoantibodies or excess proteins so accompanying medical therapy is more effective in controlling the disease. Only in a few diseases is it possible to remove the specific substance causing the disease like in the Exorim Citem 10 . However, it is possible to remove the plasma which contains the substance. The plasma is replaced with donated fresh frozen plasma or, more commonly, physiologically acceptable replacement fluid, such as a mixture of albumin and normal saline.
Plasma exchange is accomplished with a medical device called a blood cell separator.
Blood cell separators use a centrifuge or a membrane filter to separate plasma from cellular blood components. Qualified medical personnel operate the blood cell separator and monitor the condition of the patient at all times. Blood is usually drawn from a patient's arm vein by a needle which is attached to a blood tubing set. Anticoagulant is added to the blood to keep it from clotting. The blood and anticoagulant enter the compartment of the blood cell separator where the plasma is separated from the cellular components and pumped into a collection bag.