Tuesday, August 3, 2010

Peripheral Blood Stem Cell Donation: Explaining the Process

When you are a match, there are 2 methods that can be used to retrieve white blood cells: Bone Marrow Transplant (BMT) or Peripheral Blood Stem Cell Transplant (PBSCT). The method chosen is usually up to the doctor who makes this decision based on what is best for the patient. With BMT, a needle is inserted into one of your larger bones (hip, pelvis, etc.), and the marrow is drawn out. It's an outpatient surgery requiring a general anesthesia. The recovery period can be upwards of 3 weeks.

A little background on what bone marrow is used for (all of you medicos out there - please forgive my layman's explanation!). Bone Marrow Transplants are used for cancers of the blood (leukemia), aplastic anemia, lymphomas such as Hodgkin's disease and other diseases. What the doctors are really after when taking bone marrow from a healthy donor are the white blood stem cells that live in the marrow.

My patient's doctor chose the PBSCT route. The same blood-forming cells (blood stem cells) that can be donated from the bone marrow are also found in the circulating (peripheral) blood. In this method, the donor (me), gets injections of a drug called Neupogen (also known as Filgrastim) for five days prior to the donation. The drug puts the donor's bone marrow on overdrive and starts producing a multitude of white blood cells. Rather than hanging out in the bone marrow, these stem cells move into the blood stream where they can then be collected for donation.

A process called apheresis or leukapheresis is used to obtain PBSCs for transplantation. In apheresis, blood is removed through a large vein in the arm or a central venous catheter (a flexible tube that is placed in a large vein in the neck, chest, or groin area). The blood goes through a machine that removes the stem cells. The blood is then returned to the donor and the collected cells are stored. Apheresis typically takes 4 to 6 hours.

PBSCT is still in the clinical study phase. Neupogen (and Filgrastim) has been approved by the FDA to be used on cancer patients only. What I find fascinating is that my experience will be part of this clinical study. They've been using this drug for more than 15 years with no know long-term side effects, so I'm not worried. The short-term side effects of Neupogen are achy bones, a general feeling of malaise, insomnia, etc.

While all of this may sound complicated and a little scary, it pales in comparison to what the patient receiving the stems cells goes through. To prep for the transplant, the patient must go through intensive chemotherapy and radiation to kill the diseased cells as well as the blood forming cells to make room for the new cells. The scary thing to me is that it also destroys the patient's immune system so that the body can't attack the new cells. The doses of chemotherapy and radiation therapy are much higher than would be used to treat the same disease in a patient who was not getting a transplant. While these higher doses may cause more severe side effects, they may also destroy more disease cells. So you won't see me complaining about getting stuck with a bunch of needles. There but for the grace of God go I.

I don't know the woman to whom I'm donating. But as I sit here rather comfortably writing this blog, I'm realizing that for the last 10-15 days she has been going through utter hell to prepare for this transplant. Not to mention the hell she's been through since she was diagnosed with Leukemia. Can she even get excited for this prospect of a cure for her? Where does she get her strength? How long has she had to live this way? Is this the beginning of the end of her personal hell? I pray to God that it is...

And what about all of the people who can't find a match? Please, please, please. If you have read this far, please consider joining the Bone Marrow Donor Registry (www.marrow.org). There is no greater gift than to be able to give someone a second chance at life.

No comments:

Post a Comment