From this link: http://www.ibmtindy.com/faq/hla-typing.htm
HLA Typing
Special blood tests, called Human Leukocyte Antigen (HLA) typing, determine whether a patient has a suitable donor for stem cell transplant. These tests are performed on several tubes of blood drawn from the arm The matching for stem cell transplant is much more complicated than matching for red cell blood types. HLA typing is increasingly done using DNA techniques and can take several days to complete. (For information on the HLA Lab at St. Francis please refer to their on-line information at http://www.stfrancishospitals.org/hla/).
The most likely place to find a bone marrow match is within the patient's own family. Siblings (brothers or sisters) will more likely match than other relatives, such as parents, children, or cousins. All humans inherit 1/2 of their entire genetic make-up, and thus of their HLA-type, from their mother and the other 1/2 from their father. For each full sibling, a patient has a one in four (25%) chance of a full match. If you have full siblings, the chances of having a completely matched donor are:
One sibling:
25%
Two siblings:
44%
Three siblings:
58%
Four siblings:
68%
Five siblings:
76%
Six siblings:
82%
Seven siblings:
87%
Eight siblings:
90%
Nine siblings:
92%
Ten siblings:
94%
(The chance of having a donor is 1-(3/4)n, where n is the number of siblings).
With the current size of the average American family, only about 30% of patients will be found to have an acceptable HLA-matched donor within their family. Therefore, search for an unrelated donor may be necessary.
What About Unrelated Donors?
The National Marrow Donor Program (NMDP) is a federally supported organization that assists in locating unrelated donors. Currently, the NMDP has computer access to over 2 million volunteer donors from throughout the United States and other countries. How easily an unrelated bone marrow donor can be found, is dependent on the patient's HLA type. The more unique, or unusual, the HLA type, the more difficult it will be to find a sufficiently matched unrelated donor. Patients from mixed ethnic background may have very uncommon HLA- types. In addition, although the NMDP has made an enormous effort to recruit minority donors, the chances for African-Americans and Asian- Americans of finding a fully matched unrelated donor are still smaller than for Caucasian patients. Even in cases where the patient's HLA type is quite common, it can take a minimum of 4 to 6 weeks to obtain the donor's marrow. For more information about unrelated stem cell donors, and how you can become a donor, you may directly contact the NMDP (http://www.marrow.org/).
What If No Unrelated Donor Can Be Found?
In some instances, the HLA type of the patient may be so unique that finding a matched unrelated donor is impossible. If a patient cannot find a fully matched related or unrelated donor, it may be necessary to look at other options, such as using a patient's own bone marrow, a partially matched family donor or umbilical cord blood. The results of partially matched related transplants have improved considerably in the last few years. Such transplants are now feasible, but the risks are still higher than for HLA-identical sibling transplants or transplants from matched unrelated donors.
Showing posts with label HLA typing. Show all posts
Showing posts with label HLA typing. Show all posts
Saturday, March 1, 2008
Saturday, February 9, 2008
How Common are Your Alleles?
See how common your alleles are -- this will tell you about the HLA –A, B and C……
How Common are Your Alleles?
It is amazing to see this! WOW—so many rare ones out there that have never been reported to the NMDP registry!
How Common are Your Alleles?
It is amazing to see this! WOW—so many rare ones out there that have never been reported to the NMDP registry!
Thursday, February 7, 2008
How to Become a Bone Marrow Donor
Ever since we found out that J didn't have a match in the bone marrow donor registry, people often ask us, "How can I become a bone marrow donor?"
It is simple to become a bone marrow donor! No blood draw or needles required! This is something that surprises many people our family comes into contact with. The NMDP now uses a buccal (cheek) swab collection kit to collect the cells used to do the HLA (Human Leukocyte Antigen) typing.
If you are typed as part of a donor drive, chances are that you will not have to pay a fee. The cost is usually $52- $60 for caucasians. Minority donors are typed for free. You can also order a typing kit on-line at www.marrow.org The fee is tax-deductible and covers the lab cost for the tissue typing (HLA typing)
The kit comes with four q-tip like swabs. The potential donor rubs each of the four swabs in a different spot on the cheek, taking care not to touch the teeth and gums. The kit comes with sticker labels that match the paperwork filled out by the potential donor. A label is placed on each swab before placing it in a slot inside the collection kit. Once all four swabs are complete, the package is sent to the NMDP along with the proper paperwork. Once the samples are processed, they are then added to the NMDP registry computer. This process can take up to 8 weeks.
If your family has already been HLA-typed through hospital testing, you can skip the above step and be added to the registry at no cost to you. You'll need a copy of your HLA typing results and the proper paperwork from teh NMDP. These are then sent to the registry where you will be added. One tip I would suggest: contact the NMDP before you send in your paperwork. The first time we sent our paperowrk in, we learned this lesson! We sent it in with all of the kits from our donor drive (The worker from the NMDP sent them in together) and our paperowrk was lost. We were told it was because the HLA results are typed into the computer at a differnt location than where the HLA typing is processed/done.
Anyone can check to see if they have been added to the registry by going to this link. Am I on the registry? Please remeber to keep your contact information updated once you have joined the registry!
If you are ever a match for a person who needs a bone marrow transplant, you will be contacted. There are two ways that you could be asked to donate stem cells. You can find more info at the NMDP site's donation process page.
You could be asked to donate marrow for stem cells or you might be given a medication called Neupogen (G-CSF) that boosts white blood cell production, and then asked to give stem cells from your peripheral blood. The type of collection varies depending on the protocol being used for the patients bone marrow transplant.
It is simple to become a bone marrow donor! No blood draw or needles required! This is something that surprises many people our family comes into contact with. The NMDP now uses a buccal (cheek) swab collection kit to collect the cells used to do the HLA (Human Leukocyte Antigen) typing.
If you are typed as part of a donor drive, chances are that you will not have to pay a fee. The cost is usually $52- $60 for caucasians. Minority donors are typed for free. You can also order a typing kit on-line at www.marrow.org The fee is tax-deductible and covers the lab cost for the tissue typing (HLA typing)
The kit comes with four q-tip like swabs. The potential donor rubs each of the four swabs in a different spot on the cheek, taking care not to touch the teeth and gums. The kit comes with sticker labels that match the paperwork filled out by the potential donor. A label is placed on each swab before placing it in a slot inside the collection kit. Once all four swabs are complete, the package is sent to the NMDP along with the proper paperwork. Once the samples are processed, they are then added to the NMDP registry computer. This process can take up to 8 weeks.
If your family has already been HLA-typed through hospital testing, you can skip the above step and be added to the registry at no cost to you. You'll need a copy of your HLA typing results and the proper paperwork from teh NMDP. These are then sent to the registry where you will be added. One tip I would suggest: contact the NMDP before you send in your paperwork. The first time we sent our paperowrk in, we learned this lesson! We sent it in with all of the kits from our donor drive (The worker from the NMDP sent them in together) and our paperowrk was lost. We were told it was because the HLA results are typed into the computer at a differnt location than where the HLA typing is processed/done.
Anyone can check to see if they have been added to the registry by going to this link. Am I on the registry? Please remeber to keep your contact information updated once you have joined the registry!
If you are ever a match for a person who needs a bone marrow transplant, you will be contacted. There are two ways that you could be asked to donate stem cells. You can find more info at the NMDP site's donation process page.
You could be asked to donate marrow for stem cells or you might be given a medication called Neupogen (G-CSF) that boosts white blood cell production, and then asked to give stem cells from your peripheral blood. The type of collection varies depending on the protocol being used for the patients bone marrow transplant.
What is HLA typing?
This is a very good question! HLA stands for Human Leukocyte Antigen (HLA) typing.
Many Shwachman-Diamond families have been HLA typed in case their SDS child needs to go to bone marrow transplant. HLA typing is also known as tissue typing and is done for solid organ transplants, too. HLA typing is not the same as your blood type. In fact, people who have the same HLA type may have different blood types. After a bone marrow transplant, the receipient usually becomes the blood type of the donor!
HLA typing can be done through a simple blood test or through buccal (cheek) swabs. Most hospitals do the testing via a blood test, while the National Marrow Donor Program uses buccal swabs to test donors.
The most likely place for someone to find a match is in their own family. A person inherits half of their HLA type from their father and half from their mother. I found a wonderful site that explains all of this. HLA FAQ
In our family, we were first HLA typed back in 2000 when our two Shwachman-Diamond Syndrome children came back with blasts (leukemia cells) in their bone marrow. We found out then, that only one of our children has a sibling match and that should the second child need a transplant, we would have to go to the NMDP registry to search for a donor. Later, in 2006, when doctors felt that the son without a sibling match might have to go to transplant, our family was re-typed to be sure he did not have a match. He was then run through the registry where there was no match found. They were able to find a few potential mis-matched donors, but it is not known if they would be suitable donors should he need a bone marrow transplant.
Our one son inherited a rare B3901 allele, thus making it hard for him to find a donor. While is other alleles are common, they are combined in an uncommon way, thus making his haplotypes uncommon.
This is all very confusing, isn't it? When this was all happening, I bought a book on HLA typing that was very helpful. It was interesting to learn just how rare this B3901 allele is! When testing for a bone marrow donor, they look at these HLA antigens: HLA A, HLA B, HLA C, and HLA D (DR). They will likely look at HLA DQ, as well... but the other four are the main HLA antigens that ae looked at.
Each person has two of each. Each person inherits one HLA-A from mom and one HLA-A from dad, so forth and so on. In order to be a match, the donor must have inherited the same exact antigens (allele) from his parents that the recipient inherited from his parents. When going through this testing, we learned that there is less than a 2% chance that a parent would be a match for their child and grandparents have even less of a chance. The HLA FAQ link above has the statistics for siblings and other family members.
For instance, the person in need of bone marrow transplant may have the following:
HLA A - 0101
1101
HLA B - 1801
2705
HLA C - 0701
0102
HLA DR - 1101
1302
HLA DQ - 0301
0503
The donor must match at these numbers, inheriting the same antigens from his parents. For instance, the person above inherited HLA A 0101 from his mom and HLA A 1101 from his dad.
Our family held a bone marrow donor drive in March of 2007 at our church. Through this drive, we were able to get 122 people typed and added to the registry. We also know a Shwachman-Diamond family who had donor drive in celebration of the one a year anniversary of their son's bone marrow transplant. What a wonderful way to celebrate life!
I hope to eventually fill up this blog with all sorts of informational topics related to Shwachman-Diamond Syndrome. If you are interested in communicating with other SDS families and learning more, please feel free to visit the SDS Support Group page. Through this support group, parents and SDS patients have a wonderful forum for giving support and the exchanging information.
Many Shwachman-Diamond families have been HLA typed in case their SDS child needs to go to bone marrow transplant. HLA typing is also known as tissue typing and is done for solid organ transplants, too. HLA typing is not the same as your blood type. In fact, people who have the same HLA type may have different blood types. After a bone marrow transplant, the receipient usually becomes the blood type of the donor!
HLA typing can be done through a simple blood test or through buccal (cheek) swabs. Most hospitals do the testing via a blood test, while the National Marrow Donor Program uses buccal swabs to test donors.
The most likely place for someone to find a match is in their own family. A person inherits half of their HLA type from their father and half from their mother. I found a wonderful site that explains all of this. HLA FAQ
In our family, we were first HLA typed back in 2000 when our two Shwachman-Diamond Syndrome children came back with blasts (leukemia cells) in their bone marrow. We found out then, that only one of our children has a sibling match and that should the second child need a transplant, we would have to go to the NMDP registry to search for a donor. Later, in 2006, when doctors felt that the son without a sibling match might have to go to transplant, our family was re-typed to be sure he did not have a match. He was then run through the registry where there was no match found. They were able to find a few potential mis-matched donors, but it is not known if they would be suitable donors should he need a bone marrow transplant.
Our one son inherited a rare B3901 allele, thus making it hard for him to find a donor. While is other alleles are common, they are combined in an uncommon way, thus making his haplotypes uncommon.
This is all very confusing, isn't it? When this was all happening, I bought a book on HLA typing that was very helpful. It was interesting to learn just how rare this B3901 allele is! When testing for a bone marrow donor, they look at these HLA antigens: HLA A, HLA B, HLA C, and HLA D (DR). They will likely look at HLA DQ, as well... but the other four are the main HLA antigens that ae looked at.
Each person has two of each. Each person inherits one HLA-A from mom and one HLA-A from dad, so forth and so on. In order to be a match, the donor must have inherited the same exact antigens (allele) from his parents that the recipient inherited from his parents. When going through this testing, we learned that there is less than a 2% chance that a parent would be a match for their child and grandparents have even less of a chance. The HLA FAQ link above has the statistics for siblings and other family members.
For instance, the person in need of bone marrow transplant may have the following:
HLA A - 0101
1101
HLA B - 1801
2705
HLA C - 0701
0102
HLA DR - 1101
1302
HLA DQ - 0301
0503
The donor must match at these numbers, inheriting the same antigens from his parents. For instance, the person above inherited HLA A 0101 from his mom and HLA A 1101 from his dad.
Our family held a bone marrow donor drive in March of 2007 at our church. Through this drive, we were able to get 122 people typed and added to the registry. We also know a Shwachman-Diamond family who had donor drive in celebration of the one a year anniversary of their son's bone marrow transplant. What a wonderful way to celebrate life!
I hope to eventually fill up this blog with all sorts of informational topics related to Shwachman-Diamond Syndrome. If you are interested in communicating with other SDS families and learning more, please feel free to visit the SDS Support Group page. Through this support group, parents and SDS patients have a wonderful forum for giving support and the exchanging information.
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