If you are providing the blood stem cells for a transplant, they will either be collected from your bloodstream (peripheral blood) or from your bone marrow.
Collecting Stem Cells from the Bloodstream
The largest concentration of blood stem cells is in your bone marrow. However, the blood stem cells can be moved or "mobilized" out of the bone marrow into the bloodstream (peripheral blood) where they can be easily collected. Most transplants these days use stem cells collected from the bloodstream.
When blood stem cells are collected from the bloodstream, the procedure is called a peripheral blood stem cell collection or harvest.
Prior to the harvest, you will receive injections of a drug such as filgrastim (Neupogen®) or plerixifor (Mozobil®) over a four to five day period. These drugs move stem cells out of the bone marrow into the bloodstream.
Most people tolerate these drugs well, although mild, flu-like symptoms are common. The symptoms end a few days after the injections stop.
If you are collecting stem cells for your own transplant, chemotherapy drugs may be used to help move the stem cells out of your bone marrow into the bloodstream.
Peripheral blood stem cell collections are done in an outpatient clinic.
- You will sit in a comfortable chair or bed.
- A needle connected to thin, flexible tubing will be inserted into a vein in each of your arms.
- Blood will be withdrawn from one arm and passed through a machine that separates out the stem cells.
- The rest of the blood product will be returned to you through the tubing connected to the needle in your other arm.
- Each collection takes three to four hours.
- It can take one to three days to collect enough stem cells for transplant.
- If the collection takes more than a day, you can return home each night after the collection.
The procedure is painless. However, you may feel lightheaded, cold or numb around the lips. Some people feel cramping in their hands which is caused by the blood thinning agent used during the procedure. These symptoms cease when the procedure ends.
Collecting Bone Marrow
The procedure used to collect bone marrow for transplant is called a bone marrow harvest. It is a surgical procedure that takes place in a hospital operating room. Typically it is done as an outpatient procedure.
- While you are under anesthesia, a needle will be inserted into your rear pelvic bone where a large quantity of bone marrow is located.
- The bone marrow will be extracted with a syringe.
- Several skin and bone punctures are required to extract sufficient bone marrow for transplant.
- There are no surgical incisions involved, only skin punctures where the needle was inserted.
- A sterile bandage will be applied to the site when the collection ends.
The amount of bone marrow harvested depends on the size of the patient and the concentration of blood stem cells in your marrow.
Typically one to two quarts of marrow and blood are harvested. While this may sound like a lot, your body can usually replace it in four weeks.
When the anesthesia wears off, you may feel some discomfort in your hip and lower back for several days. The pain is similar to what you would feel if you took a hard fall and bruised your hip. You may find sitting for a long period of time or climbing stairs uncomfortable for a few days. The pain is usually relieved with acetaminophen (Tylenol®).