Therapeutic Apheresis

Why Is Therapeutic Apheresis Necessary?

Some diseases create substances which circulate throughout the body in the plasma portion of the blood.

In certain diseases these substances are called "autoantibodies" or antibodies which attack healthy cells or tissue. These autoantibodies are created by a mix-up in the body's immune system.

Other diseases cause an overproduction of protein, which results in slowing down the blood flow (in the same way that thick liquids move more slowly than thin ones).

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. 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 fluids, such as a mixture of albumin and normal saline.

What Actually Happens During A Therapeutic Apheresis Procedure?

Therapeutic aphersis 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. Anti-coagulant 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. The cellular components are drawn from the compartment and a replacement fluid prescribed by the physician is added to replace the volume of plasma, which is removed. The mix of cellular components and replacement fluid is returned to the patient, usually through a needle in the other arm.

The latest technology blood cell separators accomplish all the above steps in an automated, continuous, and safe manner.

The sterile tubing sets and needles are used one time only and then discarded.