Skip Navigation

If you have an allogeneic transplant, you will get healthy blood-forming cells donated by someone else. The donor can be a family member or someone unrelated to you. Sometimes, people get donated blood-forming cells from umbilical cord blood. This is the blood collected from the umbilical cord and placenta after a baby is born and made available through NMDP Registry.

First, your doctor tests your blood to find out your human leukocyte antigen (HLA) type. HLA is a protein — or marker — found on most cells in your body. Your doctors will look for a donor or umbilical cord blood that closely matches your HLA.

The best transplant outcomes (results) happen when a patient’s HLA closely matches the donor’s HLA. A close HLA match also helps lower the risk for problems after transplant. Matching HLA markers is much more complex than matching blood types.

Usually, your doctor will first look for a matching donor in your family usually a brother or sister. That’s because you inherit HLA markers from your parents. Each brother and sister has a 25% (1 out of 4) chance of completely matching you, if you have the same mom and dad. Your parents and your children always match exactly half of your HLA markers. For some people a transplant from a half-matched donor, or a haploidentical transplant, is a treatment option.

70% of patients who need a transplant don't have a fully matched donor in their family. If you don’t have a match in your family, your doctor will search the NMDP Registry for an unrelated donor or umbilical cord blood. Finding a donor can take time, so your doctor should start a donor search as soon as possible. Your doctor can look for a donor even if you don’t need a transplant right away.


Questions to ask your doctor:

• Which family members will you test as possible donors?
• If a family member is my donor, what will he or she have to do?
• What happens if I don’t have a match in my family?
• Is a reduced-intensity transplant an option? Why or why not?
• Is a haploidentical (half-matched) transplant an option for me?