The first step in planning for an allogeneic transplant is to find a suitable donor. This is done through the process of Human Leukocyte Antigen (HLA) Typing. People often assume that if their blood type matches, then their HLA types much match, but this is not the case. HLA typing is a molecular laboratory test performed from a blood sample that looks at DNA structure. Since you receive DNA from your parents, we look first at any siblings since it is likely – a one in four chance – that you match one of them. If not, or if you have no siblings, there are unrelated donor registries that can be searched to find potential HLA matched donors.
Sibling donor typing will be facilitated through the transplant coordinator, who will invite the sibling to come to our hospital to have blood drawn. For siblings living outside the New Orleans area, there are kits for the testing. The cost of the HLA typing itself will be likely be covered by the transplant recipient’s insurance.
Sibling typing is done in two stages. If you and your sibling match after the first level of molecular typing is complete, we will have a second level of molecular typing performed on the original sample. No additional blood will need to be obtained to do this. It is only after this second level that we can truly identify a donor. If your sibling does not match you at the first level, he or she will not be a suitable candidate to be your donor, and therefore no further testing will be done.
If we find that no siblings match, there is always the option of an unrelated donor. Since we will have your typing complete, we will run a preliminary search of the National Marrow Donor Program unrelated donor registry. This is free of charge and gives us an idea of the potential availability of an unrelated donor. If this is the route chosen, we look more in depth at donors on the registry and have samples of their blood sent to our laboratory to confirm HLA typing.
Once a donor has been found, whether he or she is related or unrelated, each donor goes through a health history and physical and has comprehensive lab work done to assess his or her suitability to be a donor. At times, the findings from this workup will make a person not eligible to donate. Some of these findings would include the presence of hepatitis, HIV, blood disorders, etc.
Could You Be The Match?
Every year, more than 10,000 people from all ethnic backgrounds are diagnosed with life-threatening blood diseases for which a marrow or stem cell transplant could be a cure. Seventy percent of these patients don’t have a compatible donor in their family and need to search for an unrelated donor.
People of similar ethnic backgrounds are more likely to provide tissue matches for one another. To increase the likelihood of finding matches in minority communities – especially like those throughout southern Louisiana – it’s critical that members of the African-American, Asian, Hispanic and Native American communities become part of the Be The Match Registry®.
Since tissue type is inherited, patients from diverse ethnic backgrounds have the greatest difficulty finding a suitable unrelated donor. That’s why recruiting new and ethnically diverse registry members is key to the ongoing success of the program. Adding more diverse members increases the likelihood that all patients will find a life-saving match.
Joining the Be The Match Registry® is fast, easy and painless. Anyone age 18-60 who is willing to donate to any patient in need and meets the health guidelines can join. Would-be donors simply complete a short health history and consent form, and a sample of cells is collected through a cheek swab for initial testing.
The actual donation process for the related donor requires that the donor be in New Orleans for seven to 10 days. This depends on whether the physician wants to use blood stem cells or marrow stem cells for the transplant. Marrow stem cells are obtained during a surgical procedure under general anesthesia where the marrow cells are “harvested” from the pelvic bones. Blood stem cells are collected by a process called apheresis. For this, the donor undergoes a series of daily Neupogen injections to make the stem cells move from the bone marrow out into the blood stream to be collected by the apheresis process.
Apheresis is the procedure used to collect stem cells from the peripheral blood. The collection of stem cells takes one to two days for approximately four hours each morning. A physician or advanced practice provider will see donors each day prior to being connected to the apheresis machine (cell separating machine). As a donor, your blood will be withdrawn from an intravenous catheter placed in one of your arms. It is circulated through the machine, which will separate out the stem cells and return the remaining blood back to you via a second IV in your other arm. There is only a small amount of your blood (a little over one cup) in the separator machine at any given time.
There are very few side effects associated with this procedure. The main side effects are:
- Numbness/tingling of the fingers or toes
- Numbness/tingling of the skin, especially the lips
- Feeling very cold
- Muscle cramps
These symptoms can be a sign of low calcium in your blood. This is due to Citrate, a calcium-binding substance used during the collection of your stem cells to prevent your blood from clotting while it is circulating through the machine. We encourage you to eat breakfast prior to donating. If you eat calcium-rich foods such as milk, yogurt or cheese, some of the symptoms may be prevented. Alert the apheresis staff if you experience any of the above symptoms or have any other concerns.
During the time you are undergoing apheresis, daily lab tests are done to count the number of stem cells collected. Each patient has a target goal of stem cells to collect from the donor. It may take more than one day to attain this goal. The apheresis staff will notify donors when the target goal has been met. The ideal number of stem cells for transplant is 2 million.
Donated stem cells are most often given to the recipient on the same day they are collected from the donor. Fresh stem cells are viable for 48 hours. In the event that all of the collected stem cells are not needed, the excess cells will be cryopreserved for possible future use.