Lowering High White Blood Cell Counts With Leukapheresis

Leukapheresis is a procedure to separate and collect white blood cells from the blood. Leukapheresis may be used as a treatment for certain types of leukemia or as the first step of chimeric antigen receptor (CAR) T-cell therapy.

Why is leukapheresis done?

When there are too many leukemic cells in the blood, it can cause problems with normal circulation and can crowd out healthy cells. While chemotherapy is the standard treatment for leukemia and can help reduce the number of leukemic cells, it can take several days after the first treatment for this effect to occur. Leukapheresis may be used as a temporary treatment before chemotherapy to lower the number of leukemic cells.¹

In people who are receiving CAR T-cell therapy, leukapheresis is used to remove the person's T-cells. They are a type of white blood cell. These T-cells are modified with specific receptors on their surface. These receptors are referred to as chimeric antigen receptors (CAR). The receptors allow the T-cells to recognize and attach to a specific protein found on the blood cancer cells.²

The modified T-cells are then replicated in a lab to create hundreds of millions of copies. The engineered T-cells are then infused into the person, where they find and kill the cancer cells in the body.²

How is leukapheresis performed?

During the leukapheresis procedure, the person is lying down or in a reclined position. Generally, 2 intravenous (IV) lines are used: 1 line removes the blood, and 1 line returns the blood cells and plasma that are not collected. In some people, only 1 large catheter may be used. This is called a central line.^1,3

The blood that is removed from the body goes through a machine called an apheresis machine. There, the white blood cells are separated and collected. The remaining blood is returned to the person. The procedure can take several hours to complete.^1,3

What are the possible risks?

Leukapheresis is generally a safe procedure. Some people experience:^1,4

• Numbness and tingling in the hands, feet, or mouth
• Painful muscle spasms

These symptoms are usually caused by a lowering of the amount of calcium in the blood. This can be treated with calcium given through an IV.^1,4

These are not all the possible side effects of leukapheresis. Talk to your doctor about what to expect or if you experience any changes that concern you during treatment with leukapheresis.

Other things to know

Talk to your doctor if you have any questions about leukapheresis. Before undergoing leukapheresis, tell your doctor about all your health conditions and any other drugs, vitamins, or supplements you are taking. This includes over-the-counter drugs.