What is a bone marrow stem cell transplant? And how can I become a donor?

What exactly is a bone marrow stem cell transplant? That's a pretty good question.

Well, a bone marrow transplant is similar to an organ transplant. We are taking out one system and replacing it with another.

Stem cells are "parent" cells. From them all other cells grow. So bone marrow stem cells grow bone marrow. And bone marrow in turn produces all the blood cells like white and red blood cells. The bone marrow stem cells are NOT embryonic stem cells which have been the focus of so much controversy. I am not killing any fetuses to obtain my stem cells. In my case they will come from an anonymous 39 year old male donor.

Bone marrow transplants now use bone marrow stem cells from the donor to GROW new marrow in the patient instead of completely replacing the marrow. The original bone marrow transplants became less popular when it was noticed that about half the patients died.

In the original, or first generation, bone marrow transplant, the patient's bone marrow would be killed completely off before receiving the donor's marrow. In a bone marrow stem cell transplant, the patient's marrow is not completely killed off, but just "half way" killed off with a chemical cocktail. Then instead of getting complete bone marrow, the patient gets the stem cells from the donor. This is called a "mini-transplant." The new stem cells grow new marrow. This is probably the third generation of bone marrow transplant technology. The mortality rate is far lower than a whole marrow transplant.

As the new stem cells grow new marrow it begins to attack the disease. And over a few months, the new marrow replaces the patient's old bone marrow, too. Essentially the patient is borrowing someone else's bone marrow and, hence, immune system for the rest of their lives.

As with all transplants, there are some rejection issues. In the bone marrow transplant, it's not so much a case of the body rejecting the new marrow as it is the new marrow rejecting the body. Remember the bone marrow generates the blood and immune system. So the new marrow sees the new body it is in as foreign matter and wants to attack it. So the patient receives anti-rejection medication for the first year or so.

"How does one find a donor?", you might ask. The National Marrow Donor Program runs a large database of possible donors. I say a large database, but it isn't large relative to the population of our country. Currently there are about 5 million people registered as possible donors. That's not really very many. I had 37 preliminary matches out of this 5 million. Upon further testing I ended up with two perfect matches. Wow, two matches out of 5 million. You can tell what the odds must be. So, the more donors we get in the database, the more people can benefit from this life saving transplant.

There are a number of parameters that they examine to determine how well a donor's marrow matches a particular patient. Oddly, blood type is not one of the major factors in a match. A sibling has a 25% chance of being a good match. But if that doesn't work out, one must rely on the bone marrow registry.

To join the bone marrow registry is painless. It doesn't even require a blood sample, just a mouth swab.

If you turn out to be a preliminary match for someone one day, they will want to draw a vial of your blood to do a complete match. If you are chosen to donate your stem cells, it will require just a few hours of your time. Your local donation center will put an IV in each arm. They will take blood out of one arm, run it through a machine to harvest some stem cells, and then put the rest of your blood back into your other arm. This is a pretty simple procedure and will save someone's life. The stem cells are then taken by medical courier to wherever the patient is.

To become a donor or to organize a bone marrow registry drive, contact the National Marrow Donor Program at 800-526-7809 or at http://www.marrow.org.

You can help organize a drive at your church, business, or other organization. Often these registration drives are held in conjunction with a Red Cross blood drive in order to maximize the number of people participating. It's critical that we get many more people in the marrow registry.