Collecting the Stem Cells
Where the stem cells are collected from depends on the type of disease you have and the type of transplant you need. Stem cells can be collected either directly from the bone marrow or through a process called apheresis.
Many patients receive high-dose chemotherapy after the stem cells are collected. Learn more
Stem cells that are circulating in the peripheral blood stream can be collected for later used through apheresis. During this process, blood is taken from a vein, processed through a machine that separates out the stem cells and returns the remainder of the blood through another vein back to the patient/donor.
First we have to encourage the bone marrow to produce very large numbers of stem cells and release them into the peripheral circulation, a process called stem cell mobilization. A series of injections called growth factors is given to the patient/donor in the out-patient clinic over a period of 4-7 days to encourage the production and release into the blood stream of millions of stem cells.
On the 4th day of injections the apheresis process begins and continues for as many days as it takes to collect the number of stem cells needed. The collection process can last from 1 – 4 days depending on the patient/donor.
If the person is donating stem cells for himself (autologous transplant), the patient will need to have a central venous catheter (CVC) placed in a large vein in the upper chest. This CVC is placed either by a surgeon or an interventional radiologist using local sedation and/or intravenous sedation. This catheter will be removed when the stem cell collection is completed. A 2nd CVC may be placed at the same time that will be used for the administration of the chemotherapy, blood tests, and fluid and medication administration. This catheter will remain in for the duration of the transplant.
If a donor is donating stem cells for a relative, a CVC is not generally placed if the donor as adequate veins in his/her arms. In intravenous catheter will be placed in each arm, the donor’s blood will be circulated through the apheresis machine, stem cells removed and the reminder of the blood given back to the donor. On occasion, the donor may need to have a CVC placed if the veins are not large enough to handle the volume of blood that needs to circulate through the apheresis machine.
The stem cells collected via apheresis will be analyzed in the lab and then frozen and stored in liquid nitrogen until they are needed for the transplant. Stored this way, the stem cells can be kept for 5 years or longer.
Stem cell harvest
Donor stem cells can be taken directly from the bone marrow cavity in the hip bones. This type of collection is done in the operating room under general anesthesia, so the donor is asleep during the entire procedure. The process takes 45 – 60 minutes and the donor generally goes home the same day. Bone marrow harvesting is not routinely done for autologous transplants. The Inova Fairfax Hospital Stem Cell Transplant Program generally only uses bone marrow harvesting of stem cells for matched unrelated allogeneic donor transplants.
Administering high-dose chemotherapy
High-dose chemotherapy and sometimes radiation is given after the collection of the stem cells. The purpose of the chemotherapy is to destroy any remaining cancer/abnormal cells with higher doses of chemotherapy than are used in standard chemotherapy treatment regimens.
There are many chemotherapy drugs that can be given to you. Transplant dose chemotherapy treatment plans vary with the type of cancer, its stage and the treatment protocols being used for you. Your transplant physician will discuss the best drugs and doses for your disease. You will be taught the way the drugs work and how they will be administered.
Depending on the chemotherapy used, you will have 24–48 hours of rest after the chemotherapy is given while the chemotherapy clears out of your system. During this time, you will be monitored closely by the transplant nurses and physicians in either the outpatient clinic or the inpatient oncology unit. Your CVC will be connected to intravenous fluids and anti-nausea medications.