Monday, October 13, 2008

Finding A Donor Match

Well, I am officially in the phase of "typing". This means that the same sort of extensive tests that are done to identify a donor match are being done on me. This process began about ten days ago, after finally receiving approval from my health insurance company (More on them later....). So it's pretty exciting to know that the journey has begun.

After all my particulars are identified, Fred Hutchinson will search that National Bone Marrow Registry to seek a match. There could be 1000 potential matches, there could be three. The number of "Potentials" is significant because it provides the pool from which more thorough "typing" can be done.

The actual testing performed is to determine HLA typing. "The HLA system produces a tissue type that is distinct from the red blood cell type that determines transfusion compatibility." (LLS) So it could be any gender, race, age, etc.

"The tissue type of an individual is determined by the proteins on the surface of cells." (LLS) So it is actually these proteins that determine a suitable match. They are located on chromosome six in tissue cells. My further layperson explanation is that these proteins are further divided into two groups, Class I and Class II. Class I had three subtypes, A, B, and C. Class II consists of subytpe D.

"HLA types are determined by a method called "molecular typing". In this technique, the DNA of the recipient and prospective donor are characterized to identify specific genes that direct the formation of the HLA anitigens on the surface of cells." (LLS)

Please note that I am quoting the Leukemia & Lymphoma Society on alot of this stuff. Even though I have had it explained to me a number of times, apparently I did not pay enough attention in all classes that included genetics.

Usually testing would begin with siblings. However, I have no blood-related siblings. Because of the genetic complexity of it all, it is almost the same probability that a stranger will match me as one of my children.

So the end of my layperson's explanation is that they search the registry for a potention match. If one is found, they then ask that person to do additional testing to check to see the level of compatibility on a more detailed level. If we get a bingo, that person would then be asked to be my donor.

Many of you have asked how you can check to see if you could be my donor. You have no idea what that means to me. But I do ask you to think about what it would mean to you. I am going to write more about the actual transplant process later, but please be aware that you can't be typed just for me. By entering the National Bone Marrow Registry, you must understand that you are volunteering to be a donor for anyone. If that is not a commitment you are ready to make, then now isn't the time to get tested.

If you would like further information about becoming a part of the National Bone Marrow Registry, please contact your local blood bank. They can tell you what programs are available in your area.

Ugh....Long science lesson for so early in the morning! But the good news is that my almost perfect match might already be out there.

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