The National Marrow Donor Program® (NMDP) takes great care to ensure the donated bone marrow or cord blood it collects is safe for transplant patients. (The NMDP operates Be The Match®.)
Many of the steps we take to screen adult volunteer donors and cord blood units on our Be The Match Registry® are similar to steps taken by blood banks. Before a person can donate whole blood, he or she must answer a list of questions about his or her health. These questions are designed to prevent donations from people with a high risk of having infected blood. The U.S. Food and Drug Administration (FDA) requires U.S. blood banks to ask these questions. The goal is to keep the blood used for transfusions as safe as possible for patients.
Like blood banks collecting whole blood, we want to be sure the donated marrow or cord blood it collects is as safe as possible for patients. Potential adult donors are screened at two points — before they join the Be The Match Registry and before they donate for a patient. All screening for cord blood units is done before they are listed on our registry.
Health history questions — first donor screening
Our standards protect both patients and donors. Before they can join the Be The Match Registry, potential donors answer health history questions much like those used for whole blood donors. This first screening is to check for medical conditions that could be passed on to a patient or that could make donating risky for the donor. Donors with these conditions are not accepted on the registry. These conditions include:
- Most types of cancer — except for localized skin cancer that has been completely cured
- AIDS — either being HIV positive or having risk factors for AIDS
- Aplastic anemia
- Rheumatoid arthritis
- Systemic lupus
We require a similar family health history from mothers who want to donate their baby's cord blood. The health history checks for medical conditions that could be passed on to a transplant patient through the cord blood. If the mother or other family member has any of these conditions, the cord blood unit may not be stored for possible transplant. Or in some cases the cord blood unit is stored with complete information from the family health history. A transplant doctor and patient can then decide whether or not to use that cord blood unit.
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Second donor screening and infectious disease testing
When a potential adult donor on the registry is matched to a patient and agrees to donate, he or she is carefully screened. The donor answers health history questions. A doctor performs a health exam on the potential donor. The exam includes a chest X-ray, an elecrocardiogram (EKG) and urine and blood tests. Women of child-bearing age are also given a pregnancy test.
Adult donors also give blood samples to test for infectious diseases. Blood samples from mothers who want to donate their baby's cord blood are also tested for signs of infection before the cord blood units are listed on the Be The Match Registry. We require blood samples from donors and mothers donating cord blood be tested for:
- HIV (the virus causing AIDS)
- Hepatitis B
- Hepatitis C
- Cytomegalovirus (CMV)
- Human T-lymphotropic virus (HTLV), type 1 (a virus that has been associated with leukemia and other diseases) and type 2
HIV — the AIDS virus
Potential donors who test positive for HIV, the virus that causes AIDS, are not allowed to donate. A mother who tests positive for HIV is not allowed to donate her baby's cord blood.
Hepatitis B or C
Potential donors who test positive for hepatitis B or C usually are not allowed to donate. However, if the patient and the patient's doctor agree there is an urgent medical need, they can choose to use the donor's cells. In other words, a person with hepatitis would be allowed to donate only if a transplant doctor agrees that the benefit to the patient outweighs the risk.
The rules are similar if a mother who wants to donate her baby's cord blood tests positive for hepatitis B or C. Usually the cord blood unit is not stored or listed on the registry. In some cases, the cord blood unit may be stored. Then the transplant doctor and patient will decide whether or not to use the cord blood unit.
Cytomegalovirus (CMV) is a common virus. More than half the adults in the United States have the CMV virus in their bodies. A person who is infected with CMV may feel like he or she has a cold. Over time, the person's immune system controls the virus and the symptoms go away. However, blood tests for CMV will be positive — the virus remains in the body but usually does not cause problems.
CMV is a major concern for transplant patients. After transplant, a patient's immune system is weak. A CMV infection can become active again. The active infection can appear in the bloodstream, stomach and intestines, kidney or lungs. CMV infection can range from mild to severe.
We require blood samples from donors and from mothers who want to donate cord blood to be tested for CMV. The CMV test results are given to your transplant doctors. If test results are positive for CMV, your transplant doctor will decide whether or not to use that donor or cord blood unit.
If your doctor is choosing between two or more donors who are equally suitable HLA matches for you, he or she may pick the donor or cord blood unit that has the same CMV status as you — if you test positive for CMV, your doctor may pick a donor who tests positive for CMV, and if you test negative, your doctor may pick a donor who also tests negative.
You are at risk for a CMV infection after transplant if either you or your donor test positive for CMV. If you are at high risk for CMV, your transplant doctors will give you drugs to help prevent CMV from becoming active or will test you frequently for CMV infection so you can be treated quickly if it occurs.
If a donor's first screening test is positive for syphilis, a second, more accurate confirmatory test is done. (False positive results in screening tests for syphilis are common.) If the confirmatory test is also positive, the donor will not be allowed to donate. If the confirmatory test is negative, the donor may donate. We report all screening and confirmatory test results to your transplant doctor.
In the same way, if a mother who wants to donate cord blood tests positive for syphilis in a screening test, but not in a confirmatory test, the cord blood unit will be stored. If the confirmatory test is positive, the cord blood unit will not be stored.
HTLV stands for human T-lymphotropic virus. Type 1 of this virus has been associated with leukemia and other diseases. If a donor tests positive for HTLV type 1 or 2, we will tell your transplant doctor. The donor may still donate if you and your transplant doctor choose to use that donor. However, if a mother who wants to donate her baby's cord blood tests positive for HTLV type 1 or 2, the cord blood unit is not stored.
West Nile virus
Doctors in the United States are concerned about the spread of the West Nile virus (WNV). WNV is spread by mosquitos. Doctors know WNV can also be transmitted through a transfusion of infected whole blood. The U.S. Centers for Disease Control is trying to learn whether WNV can also be transmitted through solid organ transplants.
Mothers who want to donate their baby's cord blood are tested for WNV. If they test positive, the cord blood unit will not be stored or listed on the registry.
We also takes other steps to protect patients and donors. Our Donor and Patient Safety Monitoring Committee studies all the steps in the donation and transplant process. It watches for any unusual side effects on donors and patients, and it develops policies to ensure the process is safe. The committee includes doctors from transplant centers, donor centers and collection centers, a donor and a patient who is either waiting for a transplant or has already had a transplant.