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The Search Process

A bone marrow or cord blood transplant (also called a BMT) that uses blood-forming cells from a donor or cord blood unit is called an allogeneic transplant. If you need an allogeneic transplant, your doctor will look first for a donor in your family. Each brother and sister who has the same parents as you has a 25% chance of matching you.

However, 70% of patients do not have a suitable donor in their family. If you do not have a donor in your family, your doctor can search the National Marrow Donor Program (NMDP) Registry for an unrelated donor or cord blood unit for you. The NMDP Registry lists nearly 7 million potential volunteer donors and more than 70,000 cord blood units and provides access to an additional 4 million volunteer donors through agreements with international cooperative registries. Your doctor can look for adult donors and cord blood units in the same search of the Registry and choose the option that is best for you.

Your potential matches on the NMDP Registry

If you are not working with a transplant center, you may find NMDP's MatchView^SM a helpful resource. You can use MatchView to see how many potential donors and cord blood units you may have on the NMDP Registry. MatchView does NOT start a donor search. Instead it provides information to help you talk with your doctor about whether an unrelated donor or cord blood transplant is a treatment option.

When does my doctor start searching for a donor?

It can take time to select a donor or cord blood unit and prepare for transplant. Beginning the donor search early may improve your chances of getting a transplant when you need one. Your doctor can do a preliminary search of the NMDP Registry while you are looking at treatment options or getting other treatment for your disease. A preliminary search can tell your doctor how challenging the search for a donor may be. Your doctor can use this information to help plan your treatment.

If a transplant is an option for you, it is also a good idea to see a transplant doctor (have a consultation) early after your diagnosis. A transplant doctor can work with your primary doctor to identify the best time for a possible transplant and to plan early treatments that will not rule out a transplant later. (For more information, see When to Consider Transplant.)

Steps of the search process

Step 1. Your doctor requests a free preliminary search

Any doctor can ask for a preliminary search of the NMDP Registry. A preliminary search is a one-time snapshot of potential donors and cord blood units on the NMDP Registry that may match you. Your primary doctor can do a preliminary search early while planning your treatment. If you have already been referred to a transplant center, your transplant doctor will do the preliminary search.

When your doctor submits a preliminary search request to the NMDP, he or she will include your human leukocyte antigen (HLA) tissue type. The HLA tissue type is used to match you to potential donors or cord blood units.

A preliminary search of the NMDP Registry is free. Your doctor can submit this request through this Web site. A preliminary search for an unrelated donor can be done while your family is being tested as possible donors for you.

Step 2. Preliminary search results are interpreted

The NMDP sends preliminary search results to your doctor within one working day after he or she has submitted the request. The results show a list of donors and cord blood units that may be a suitable match for you. These early results may show many or few potential matches. Further testing is needed to find out which, if any, of the potential donors or cord blood units are suitable for you.

If your primary doctor does the preliminary search, it is important for him or her to review the results with a transplant doctor who has experience in the donor search process. Your doctor can also talk to HLA experts at a transplant center or the NMDP for help interpreting the search results.

Step 3. Your doctor refers you to an NMDP transplant center

The next steps of the search process are done by a transplant doctor. If your primary doctor has not already referred you to a transplant doctor, he or she will do so now. If you need an unrelated donor or cord blood unit from the NMDP Registry, you will need to go to a transplant center in the NMDP Network. NMDP transplant centers are required to meet NMDP standards for quality and transplant experience.

The transplant team will evaluate your health, disease stage and other factors to decide if transplant is a good treatment option for you. The transplant team will also tell you more about the transplant process, including how they will search for your donor or cord blood unit and the costs involved. Most transplant centers require approval from your insurance company before starting a formal search. Most transplant centers also require you to identify a caregiver who will help care for you during your transplant and recovery.

Step 4. Your transplant doctor starts a formal search

Further testing is needed to find out whether potential donors or cord blood units listed on the preliminary search results are suitable matches for you. This testing is done through a formal search. NMDP transplant centers can do a formal search by requesting further testing of potential donors or cord blood units on the NMDP Registry. The decision to do a formal search is a formal agreement between you and the transplant center. Because donors may be contacted and lab tests done, there are costs for a formal search.

Some insurance companies cover some or all search costs and others cover none. The transplant costs your insurance covers may depend on your disease, treatment plan and other factors.

For questions to ask your insurance company about transplant coverage, see Insurance and Transplant Coverage Information.
For more information about search costs at NMDP transplant centers, see Choosing a Transplant Center: A Patient's Guide.

A transplant center will test several potential donors or cord blood units to find the best one for you. If an adult donor appears to be a good match, he or she must be contacted to be sure he or she is healthy, able and willing to donate. If one or more cord blood units are a suitable match for you, your doctor will also look at the number of blood-forming cells in the cord blood units. The number of blood-forming cells in a transplant needs to be suitable for the size of the patient — larger patients need more cells.

It is your transplant center's job to find a donor or cord blood unit for you. Finding a donor is not your responsibility. Your transplant team will use their experience and research findings to select potential donors to test further. The goal is to find the best donor or cord blood unit for you in the shortest amount of time. It can take as little as a few weeks to as long as two months or more to find a donor or cord blood unit. Sometimes no suitable donor or cord blood unit can be found. If that happens, your doctor will look at other treatment options. These options might include using a partly matched family member (haploidentical donor).

Your treatment during the search

Usually while your transplant center searches for your donor or cord blood unit, you will return to your primary doctor for care. You and your primary doctor and transplant doctor need to keep in contact with each other. If your health or disease changes while you are waiting for a donor to be found or your transplant to take place, you and your primary doctor should tell your transplant center. Your doctors may decide it is in your best interest to delay the transplant. It is important for you to be as healthy as possible when you have your transplant.

Step 5. Your transplant doctor identifies a donor or cord blood unit

When your transplant doctor selects a suitable adult donor, your transplant center will retest the donor's HLA typing to confirm that it matches yours. The selected donor will have more blood tests and a physical exam to ensure that he or she does not have an infection or disease that could be passed on to you through the transplant. The tests also make sure donating will not be too risky for the donor. These steps are part of the NMDP Guidelines to Safeguard Patients.

Your transplant doctor will also choose whether to ask for marrow or peripheral (circulating) blood cells (also called PBSC) from the donor. Doctors are still trying to find out more about whether one source of cells leads to better transplant results than the other.

For more information about a current study that is comparing peripheral blood and bone marrow as sources of cells for transplant, see PBSC vs. Marrow Clinical Trial.
To learn more about how marrow or peripheral blood cells are donated, see Steps of Bone Marrow & PBSC Donation.

The NMDP will explain the donation process to the donor. The donor must understand what is involved before he or she agrees to donate.

If your transplant doctor chooses cord blood as the best source of cells for you, your transplant center will test a sample of blood stored with the cord blood unit to confirm that it matches you. Screening for infectious diseases and other medical problems is done before the cord blood units are stored. To learn more about how cord blood is collected for transplant, see Umbilical Cord Blood Donation.

Step 6. Cells are collected and transported to the transplant center

For adult donors, the NMDP works with your transplant center and your donor's donor center to schedule a collection date. The date depends on your health and when you will be ready for transplant as well as on the donor's schedule. On the scheduled date, the marrow or blood cells are collected. A trained courier brings them to your transplant center within 24-48 hours after they have been collected, and you receive your new cells.

If your transplant doctor chooses cord blood for your transplant, the transplant center will ask for the cord blood unit to be shipped. Cord blood is stored frozen and can be delivered to your transplant center within 24 hours. The NMDP will arrange the shipment of the cord blood to your transplant center. When you have finished your pre-transplant treatment (preparative regimen) and are ready for transplant, the cord blood is thawed and you receive your new cells.

Patient and donor confidentiality

You will not know who your donor is at the time of your transplant. The NMDP follows strict confidentiality standards to protect the privacy of both you and your donor. According to these standards, you and your donor cannot learn each other's identities for at least one year after your transplant. Some centers do not ever allow you and your donor to learn each other's identities. If you have a cord blood transplant, you will never learn who donated the cord blood.

Resources for your doctor

If your primary doctor wants to know more about searching for a donor or cord blood unit on the NMDP Registry, you can find information to share in the Physician Resources section of this Web site: