Becoming a Donor
Your ability to donate bone marrow or peripheral stem cells depends on whether:
- Your tissue antigens are compatible with the recipient, and
- You are healthy enough to withstand the donation process.
To assess your ability to donate, there are several tests you will undergo. The form and timing of the tests will be determined by the donor registry, but here are typical tests:
1. Your Age
The first screen is age; you must be at least 18 but not older than 60 (age 55 for some registries). That is, at the very least you must be an adult to donate. And, research has shown that donations from older adults are less effective, hence registries impose a maximum age for donors.
2. Preliminary Tissue Compatibility
The first step is to determine your tissue type. Testing is done by drawing a blood sample or through a cheek swab. If you are a donor volunteer, these tests are part of the registration process. You may have to pay for the testing, which ranges from $50 to $100. The test identifies your human leukocyte antigens (HLA). The results are input into the marrow registry and used to make a preliminary match with compatible recipients.
You do not need to have the same blood type as the potential recipient.
3. Detailed Blood and Tissue Compatibility
Once a potential recipient has been matched on a preliminary basis, more detailed compatibility testing is done. Again, a blood sample or cheek swab is taken from you and tested.
DNA Testing. One test that’s done is DNA testing. This testing is similar to the HLA testing but is more detailed. It uses sophisticated laboratory tests to determine the DNA of your antigens and compares the DNA code to those of the recipient.
Crossmatching. Crossmatching is a further testing of antigen compatibility. In this test, white blood cells from you are mixed with blood from the recipient. If the white blood cells are attacked and die, then the crossmatch is “positive,” which is a negative as far as your ability to donate. It means the recipient is “sensitized” to you—the recipient has antibodies to some of your antigens—so the recipient’s immune system would turn on the donated marrow and destroy it. If the crossmatch is negative, you are compatible with the recipient.
Note: The tissue typing is rigorous because compatibility between the donor and recipient is essential to a successful transplant. As a consequence, many potential donors are ruled out. The odds of two individuals matching range from 1 in 20,000 to 1 in 50,000 depending on such factors as ethnic background. This is the primary reason why unrelated donation is so important.
4. Your General Health
You will have a complete physical exam as part of the screening process. You will share your medical history and have a series of tests, such as a chest x-ray, electrocardiogram, blood tests, urine tests, and so on. Female donor candidates may also undergo a gynecological exam and mammography. You will also undergo testing for infectious diseases, such as HIV, hepatitis B, hepatitis C, syphilis, and other diseases. The purpose of the exam is to ensure you don’t have any health conditions that would make it difficult for you to endure the donation process or that could result in your infecting the recipient with disease.
There are some health conditions that will prevent you from being a marrow donor. The National Marrow Donor Program lists the following:
- HIV or risk of HIV
- Hepatitis or risk of hepatitis
- Heart disease or cancer
- Lung disease
- Diabetes requiring insulin
- Diseases that affect blood clotting or bleeding
- Recent back surgery or severe or ongoing back problems
- Autoimmune or neurological disorders such as lupus, rheumatoid arthritis, or multiple sclerosis
- Being an organ or marrow transplant recipient
- Significant obesity
- Sleep apnea
5. Other Assessments
Depending on hospital guidelines and transplant team protocol, there may be other assessments, such as psychological and financial reviews:
- Donor and collection centers routinely provide an educational session on marrow donation as part of the registration and donation process. During that session you will be counseled about such topics as your ability to remain anonymous (for nondirected donation), the screening requirements, the risks of donation, your rights to withdraw, the impact on potential recipients, insurance coverage, possible subsequent donations, and alternative collection methods. (The content listed here is based on guidelines suggested by the World Marrow Donor Association.) This is an opportunity to ask yourself questions. What are your motives? Is it important to you to know the recipient and for them to know you? Are you committed to donation or were you pressured? If you decide donation isn’t for you, the donor or collection center will arrange to give you an out without embarrassment.
- You may also be asked about financial considerations. The monetary demands of donation are modest, but you still need to be aware of the potential financial consequences. Can you afford the cost of the preliminary registration test? Can you get off work for testing, donation, and recovery? Medical expenses and travel expenses generally are covered by the medical insurance of the recipient or the marrow registry, but lost wages are not. What kind of paid sick leave and vacation do you have from your employer? Do you have other financial resources available if you need them? Do you need help raising money?