I am really curious about bone marrow transplants, I see fund raisers and donors needed in the paper every so often and I think I really want to donate. I’m an organ donor, afterall, but it’s going to be some time before those are going to be up for grabs.
Here are my mental wanderings:
1.When they test someone to see if they are compatable with the person that is sick, what exactly goes on in the testing? What exactly are they trying to match up?
2. Is your name then stored on some kind of national registry in hopes of helping someone else involved?
3. When they take bone marrow from the donor, how long is it viable?
4. What is the success rate if a match is found?
5. Can pregnant women do the testing?
6. What diseases does a Bone Marrow Transplant help cure/fight?
This is more complicated than I can fully answer, but here’s the basics:
Step 1: Kill all of the existing bone marrow cells, especially the “stem” cells the can differentiate into lymphocytes, granulocytes (neutrophils, eosinophils, baso phils), platelets, and red blood cells. This is accomplished by high-dose chemotherapy +/- radiation therapy.
Step 2: Give “new” marrow. Options are saved marrow from yourself (autologous), donor marrow, or, now, stem cells (either autologous or donor-derived).
Step 3: Wait. Give growth factors. Pray. Hope the new marrow grafts well & makes enough immune cells to kill off all the viruses, bacteria, & fungal infections that are trying to commandeer the patient’s body for their own purposes. (True story - medical students, interns, and residents sometimes refer to transplant patients as human Petri dishes. Sometimes = when the staff doctors are out of earshot)
In the immune system’s perspective, you are not grafting a bone marrow into a patient; you are grafting a patient onto a bone marrow. This is why bone marrow transplant donors have to match the recipient exactly. Otherwise, the new marrow, can cause an immune attack on the patient (called graft vs. host; often fatal).
Now for the questions:
They draw blood & separate out the lymphocytes. Then they look at the proteins stuck in the cell membranes of your lymphocytes. These are called HLA (human lymphocyte antigen) markers & determine what proteins, your immune system will or will not react against. Ideally, your HLA markers should match up EXACTLY with the recipients for you to be a good donor. This is why it takes thousands of potential donors to find a match for an unrelated recipient. Sibs have about a 25% chance of an exact match.
That’s up to you. Most people are “captivated” by a particularly heart-pulling tale & go to give a tube of blood. Once there, they learn that there are thousands of Americans whose only chance at life is finding a donor. Pretty hard to say no to. So most people, once typed, do put their names into a data bank. It’s still a minority, but many patients find a donor as soon as they’re typed & entered into the registry.
Too technical for me. IIRC, if actual marrow is being donated, it has to be transplanted within at most 24 hours - generally this means the donor travels to wherever the patient is being treated. Stem cells, on the other hand, have a lot longer “shelf life”, but also take longer to engraft.
It depends on lots of factors - matching, what disease is being treated, how successfully the antibiotics are at keeping infections in check are some of the key ones.
I assume you’re asking can pregnant women donate marrow… There would be no reason not to draw a little blood to test a pregnant (potential) donor, but no reason to test if she couldn’t donate due to pregnancy. I suspect if she were a perfect sib match, it would be hard not to let her donate if that were her choice, but that being a random unrelated donor would be discouraged. I can’t think of any reason she wouldn’t be allowed to donate stem cells, however.
Many. First are non-cancerous conditions in which the bone marrow just doesn’t make something that is needed. Aplastic anemia & agranulocytosis are examples. They respond quite well. I think SCID (Severe Combined ImmunoDeficiency) may also be treatable, but am less sure on this one.
Second are bone marrow cancers (leukemias). By giving very high doses of chemo & radiation, you hope you are completely killing off every single cancerous cell. Dicey proposition. Works better in kids than in adults.
Third are for “solid tumors”. Breast cancer is the most common. Normally, the biggest limitation to how much chemo a healthy body can withstand is how quickly the bone marrow will come back in between. It does no good to kill the cancer, but have the patient die of infections. Here, you can give one catastrophic (for the bone marrow) dose of chemo/radiation & hope that it also wipes out the cancer cells. And hope that the new marrow grows in…
A patient told me one of the best analogies I’ve heard for this therapy - that the docs are seeing how far into hell they can push you & still be able to pull you back out.
Fortunately, for the donor, it is much easier. Bone marrow donation is not painless; depending upon the number of sites aspirated from, sometimes general anesthesia is used. It is not a commitment to take lightly. But it can truly make the difference between life & death for someone’s kid or mom or brother… Stem cell donation is much simpler; just a long blood draw (like donating blood).
Something you might also check on is becoming an apheresis donor. This involves donating blood, having the platelets (or other blood components) removed from your whole blood (while you wait!) and the rest pumped back into you. My understanding is that the platelets are used to treat many of the same conditions. I was also put into the bone marrow registry as part of the apheresis program.
Call your Red Cross. They’ll tell you all about it.