I spoke with my MUD (Matched Unrelated Donor) Transplant Coordinator this morning, and she had good news and not so good news. Because the not so good news was difficult to comprehend, I am going to provide some details to HLA typing that might help those who are wanting to more fully understand what all is going on.
The good news was that the person who went in for their blood test last week was not only a 10 out of 10 match but was even better at 13 out of 14. Some facilities require 6 of 6, 8 of 8, others 10 of 10. The more markers that match the better the results. MD Anderson looks for 10 of 10 or better. So 13 of 14 is really good.
What are these “markers?” Human Leukocyte Antigen (HLA) typing is used to match patients and donors for bone marrow or cord blood transplants (also called BMT). HLA are proteins — or markers — found on most cells in your body. Your immune system uses these markers to recognize which cells belong in your body and which do not.
Several of you have also asked the difference between a bone marrow transplant and a stem cell transplant. Basically not much except for how they retrieve the stem cells. Bone Marrow Transplants (BMT) or Stem Cell Transplants are done to restore the body's ability to produce the different cells that make up the blood. Bone marrow is the spongy tissue inside large bones. It contains immature stem cells. Stem cells mature to become red blood cells that carry oxygen, white blood cells that help fight infection, and platelets that help stop bleeding. In a bone marrow transplant, the donated stem cells are taken from bone marrow. In a stem cell transplant, the donated stem cells are taken from circulating blood. Bone marrow donation is a surgical procedure done in a hospital. The donor is given anesthesia; then a needle is used to remove marrow from the hip bone (similar to a bone marrow biopsy). Peripheral blood stem cell donation is done in an outpatient setting. The donor is given medication over several days to increase the number of stem cells in the bloodstream. Then a needle is inserted into an arm vein to draw out the blood. The blood passes through a cell separator machine that removes the stem cells. The rest of the blood is returned immediately to the donor. This is the now the more common procedure.
The not so good news is where it starts getting confusing. When mine was tested, they discovered that I have HLA antibodies in the DP (more on this shortly). The antibodies are similar to the resistance we develop to Chicken Pox after we’ve had it. That’s a good thing with Chicken Pox. But if I have a resistance to a part of my donor’s cell makeup, it could inhibit engrafting. Engraftment is when the donated cells start to grow and make new blood cells. A close HLA match reduces the risk of a post-transplant complication called graft-versus-host disease (GVHD). GVHD occurs when the immune cells from the donated marrow (the graft) attack your body (the host).
There are several groups of HLA markers. MD Anderson primarily looks at A, B, C, DR, and DQ. My antibodies are on DP, which most facilities don’t even test. But because MD Anderson looks for the best match at a detailed level, my antibody situation will be a factor to consider. If this 22 year old female with 13 of 14 matches ends up being the best match available, then there are extra steps that can be taken at time of transplant to help overcome the antibody issue. For now, they will continue to search for the best match and keep this one on the back burner.
For more information on HLA typing, here are a couple helpful sites.
The lack of a fully matched donor (8/8 matched, i.e., matched at HLA-A, -B, -C, -DRB1) does not preclude transplantation as a possible treatment option, because transplant outcomes are generally better when patients are transplanted earlier in their disease rather than later.
The NMDP (National Marrow Donor Program) therefore recommends not delaying transplant in the hopes of finding a better matched donor later. The NMDP bases this recommendation on a 2007 study of 3,857 transplants demonstrating that 6/8 patients transplanted in an early disease stage do better than fully matched 8/8 patients transplanted in advanced disease stage. [5] Because disease stage at the time of transplant is the only factor under direct control of a physician, an early referral is perhaps the single most important step that can affect survival. (See the NMDP Clinical Fact Sheet on Outcomes in Unrelated Hematopoietic Cell Transplantation for additional data.)
(Taken from BeTheMatch.org.)
With that in mind, I am going back to my local oncologist tomorrow, and then we will meet with my transplant doctor on January 2. The MUD Coordinator will keep the transplant doctor and the head of the CLL department in the loop with regard to possible donors. The doctors at MD Anderson were very pleased with our proactive approach. While it is scary to say the least, the potential for long-term survival is greater with this plan.
I think that this past month of increased fatigue has helped me begin to accept what the next year or so is going to be like. I am learning my limits, and while I still push them often, I now know how far is far enough. As I wrote on an earlier post, we continue to prepare. It doesn’t feel like much sometimes, but it is all I can do right now. Prepare and pray. Pray for the right donor. Pray for the right timing for the transplant. Pray that the right pre-transplant treatment is chosen. Pray that my body accepts the transplant. Pray for no infections. Pray for Paul and my mother as they provide care for me before, during, and after. Pray for continued positive attitude. Pray for peace.
“And the peace of God, which surpasses all understanding,
will guard your hearts and your minds in Christ Jesus.”
Philippians 4:7
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