Matching blood stem cell donors and patients

Blood stem cells are used to cure or treat over 75 diseases including leukemia, lymphoma and sickle cell. The donation process begins with finding a blood stem cell donor match—and that match could be you.

 For HLA matching, doctors look at up to 12 different markers on your DNA. This makes finding a match much harder because there are millions of possible combinations, and usually doctors want to match eight to ten of those 12 markers.

When handling umbilical cord blood donations though, doctors may only need to match four to six markers. Because of this matching process, NMDP^SM is always seeking more umbilical cord blood donors.

With such a diversity of HLA types, the amount of time it takes for donors to match with patients can vary. If you have a common HLA type, you could match within a few months or years. If your type is rarer, it could take longer. Some registry members will never get matched.

Every registry member is essential to our work at NMDP—and there are even more ways to help get patients to transplant. From volunteering and financial giving to advocacy, it all helps further our mission.

As the diversity of the population increases, more unique HLA types are being created, making full matches harder to find. However, new research and clinical trials from CIBMTR® (Center for International Blood and Marrow Transplant Research®) (Opens in a new tab) , a research collaboration between the Medical College of Wisconsin and NMDP, is making it possible for patients to have a successful transplant even when paired with a donor who isn't a full match. This initiative, called NMDP Donor for All, means more transplants for patients in need and offers more opportunities to donate for NMDP Registry members!

When you become a match for a patient, you may be their only match. It's important to respond to NMDP right away to address any of your concerns and confirm you're willing and able to be a donor.

You'll be asked to confirm your commitment to donate and complete a thorough health history questionnaire.

This 90-minute session is designed to fully inform you about blood stem cell donation. You'll have opportunities to ask questions and will be asked if you're willing to move forward. We'll speak with you about the possible risks, the potential side effects and the two methods of donation: peripheral blood stem cell (PBSC) and bone marrow donation collection. The patient's doctor selects the donation method based on what is best for their patient.

If you agree to donate, you'll be asked to confirm your decision by signing a "consent to donate" form.

You'll have a physical exam to see if donating would pose any risk to you or the patient.

Before you donate, you'll be asked to provide several blood samples to confirm you match with the patient. This is usually done in two to four appointments, which will be scheduled by your donor representative.

Once the blood samples are processed and it's confirmed that you're the best match for the patient, you're ready to become a donor! Find out more about the donation process here: You're a match: A donor's online guide to donation (Opens in a new tab).

Our guide to donation is available in the following languages: Spanish (Opens in a new tab), Portuguese (Opens in a new tab), Korean (Opens in a new tab), Vietnamese (Opens in a new tab) and Chinese (Opens in a new tab).

Peripheral blood stem cells are blood-producing cells that create white and red blood cells as well as platelets. PBSCs are collected via a non-surgical process called apheresis. The collection process involves drawing blood from one arm and returning it into the other arm using an IV. Most donors will use this method to donate.

Learn more about the PBSC donation process

Bone marrow is soft tissue inside bones that contains blood stem cells. Bone marrow is collected via a surgical procedure performed while under anesthesia. During the procedure, doctors will use needles to extract liquid marrow from both sides of the back of your pelvic bone. Typically, donors can expect to be at the hospital from early morning until late afternoon, but some may be asked to stay overnight.

Learn more about the bone marrow donation process

To join the registry, you must be between the ages of 18 and 40. That's because research shows cells from younger, healthy donors lead to more successful blood stem cell transplants for patients, and doctors request donors in the 18 to 35 age group nearly 80% of the time. If you're over 40, though, you could still be matched with a patient. Potential donors remain on the registry until 61, unless they choose to remove themselves earlier.<

If you're unable to join the donor registry because of age or other restrictions, you can still play an important part in helping patients. NMDP offers multiple ways for you to channel your enthusiasm for our mission to help save lives.

A person's ethnic background plays a large part in finding a match. Because patients are more likely to match with a donor that shares their ethnicity, it's important for us to encourage diversity within the registry.

The majority of blood stem cell donors need to travel as part of the donation process. NMDP will work hard to find a donation day that works for both you and the patient, and any travel expenses incurred as part of donating will be covered for you and up to one companion.

You'll never be alone on your donation journey. We have resources and expert staff members who will be with you along the way. Our support programs provide several resources to meet the unique needs of donors while keeping you safe and your identifying information private.