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Collecting cells for CAR T-cell therapy


Your child might benefit from a treatment called CAR T-cell therapy. It helps the body’s defense system, called the “immune system,” get better at destroying cancer cells. You might also hear your St. Jude team call it “immunotherapy” (say IM-you-no-THER-uh-pee) or cellular therapy.

The first step is collecting T cells from the blood in a procedure called “apheresis.” Say “Ay-fur-EE-sis.” A “T cell” is a type of white blood cell, and apheresis takes white blood cells from the blood.

The blood for T cell collection may come from your child or a donor. We might use the cells right away to make CAR T cells, or freeze them in case we need them later.

How apheresis works

Apheresis is done in the blood donor center or the hospital if your child is staying there. They may lie in a comfortable chair during the procedure. A nurse or other St. Jude team member places an IV in both arms. One IV or central line is for blood to flow out, and one allows blood back in after we collect the needed cells. If your child already has a central line, we might use this instead. Or, we might put in a central line if your child needs it.

The blood that flows out goes through a machine. This machine separates white blood cells from the rest of the blood and stores them. Then, the rest of the blood goes back to the body through the other IV or central line.

The St. Jude team counts the white blood cells after the procedure. We do this to learn if we have enough. Apheresis usually takes 3 to 6 hours and counting takes 1 or 2 hours. After that, we know if we have enough cells. Your child or the donor might need apheresis again if we did not get enough cells on one (1) day. They might have it again the next day or another time.

Apheresis side effects

The most common side effects include:

  • Nausea,
  • Fainting,
  • Feeling dizzy, and
  • Having pain or bruising where the needle or central line was placed.

These side effects are similar to what you might have from giving blood.

Apheresis can also lower the number of red blood cells and platelets your child has. They might need extra blood (a blood transfusion) if this happens. A transfusion is a procedure where we give you someone else’s blood or other blood cells because you do not have enough.

Side effects from apheresis medicines

Your child or the donor might have some side effects from anti-clotting medicines we use during the procedure. These medicines keep blood in liquid form while it is out of the body. They might cause the following side effects:

  • Muscle cramps,
  • Numbness or tingling,
  • Feeling cold, and
  • Feeling anxious.

One of the anti-clotting medicines, sodium citrate, temporarily lowers the body’s ability to use calcium. So, we might give calcium to prevent or treat these side effects.

Apheresis can temporarily raise your child’s risk of bleeding too much. This is because we give your child a medicine that keeps blood from clotting during the procedure. “Clotting” means to stop flowing when it should. The medicine used for apheresis can lower your child’s levels of a blood cell called “platelets.” These cells help blood clot, so lower platelet levels raise the risk of bleeding.

The risk of bleeding is even higher if you take certain medications before or after the procedure. These medicines include aspirin and NSAIDs, such as ibuprofen and naproxen. Your child or the donor should avoid aspirin, NSAIDs, and medicines that contain them for one (1) week before apheresis. Also, avoid these for 2 weeks afterward. If you are not sure a medicine is safe, please ask the doctor or nurse. Children under 18 should not take aspirin or medicines with aspirin.


If you have questions about collecting cells for CAR T-cell therapy, please ask your child’s doctor or nurse.


This document is not intended to take the place of the care and attention of your personal physician or other professional medical services. Our aim is to promote active participation in your care and treatment by providing information and education. Questions about individual health concerns or specific treatment options should be discussed with your physician.

St. Jude complies with health care-related federal civil rights laws and does not discriminate on the basis of race, color, national origin, age, disability, or sex.

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