What are the requirements for stem cell donation?

Every year, thousands of patients with blood cancers and other diseases need a stem cell transplant to survive. For many, the chance of a cure depends on finding a volunteer donor, which is why understanding what are the requirements for stem cell donation is so critical.

Quick Summary

Becoming a stem cell donor requires being in good general health and typically between 18 and 40 years old, though some registries accept donors up to 60 based on patient need. Compatibility is determined by a genetic test called Human Leukocyte Antigen (HLA) typing, and matched candidates must pass a thorough medical screening.

Key Points

• Age and Health are Critical: Prospective donors must be healthy, typically between 18 and 40 years old, with exclusions for major chronic conditions like cancer and autoimmune disease.

• HLA Typing is How You're Matched: A cheek swab or blood test is used to determine your Human Leukocyte Antigen (HLA) type, which must be a close genetic match to the patient.

• PBSC is the Most Common Method: Around 90% of donations are non-surgical, similar to a blood or platelet donation, after receiving injections to boost stem cell production.

• Bone Marrow Donation is Surgical: For about 10% of cases, marrow is surgically collected from the pelvic bone under anesthesia, involving a shorter procedure but longer recovery time.

• Diversity is Urgently Needed: Due to the genetic nature of HLA, patients from underrepresented ethnic groups have a harder time finding matches, highlighting the need for a more diverse donor registry.

• Commitment is Required: Joining a registry means being prepared to donate if you are ever matched, which may involve travel and multiple medical appointments.

The Importance of Stem Cell Donation

Stem cell transplants are life-saving medical procedures for patients with various conditions, including leukemia, lymphoma, sickle cell disease, and other blood disorders. The donated stem cells, which can be collected from bone marrow or peripheral blood, are used to replenish a patient's unhealthy bone marrow. This process allows the recipient's body to produce new, healthy blood cells. The vast majority of patients must rely on an unrelated donor found through a national registry. A single donor has the potential to offer hope and a second chance at life to a patient in need.

Primary Eligibility Requirements

To ensure the safety of both the donor and the recipient, national donor registries have strict eligibility criteria. While the specific rules can vary slightly between organizations, the core requirements are similar across the board.

Age Guidelines

• Optimal Age for Registration: Most registries actively recruit individuals between the ages of 18 and 40. Research has shown that stem cells from younger donors lead to better long-term outcomes for patients.
• Upper Age Limits: Many registries will keep a donor on file until age 61. However, the upper age for initial registration may vary. Some organizations will consider donors up to age 60, especially if they are a perfect match for a patient.
• Parental Consent: Individuals under 18 cannot donate because it is a voluntary medical procedure requiring informed consent, which a minor cannot legally provide.

General Health

• Excellent Medical and Psychological Health: A potential donor must be in overall good health. This is assessed through a comprehensive medical questionnaire, physical examination, and blood tests once a match is identified.
• Body Mass Index (BMI): Many registries have BMI guidelines to ensure donor safety. For example, some organizations require a BMI of under 40.

Health Conditions that Disqualify Donors

Certain pre-existing medical conditions can disqualify an individual from donating. These exclusions are in place to protect the donor from complications and minimize risk for the patient.

• Cancer: Most cancer diagnoses (excluding some types of skin cancer) are disqualifiers, especially if chemotherapy or radiation was involved. Some specific early-stage or in situ cancers that are fully treated may be exempt.
• Autoimmune Disorders: Conditions such as lupus, rheumatoid arthritis, Crohn's disease, and multiple sclerosis generally prevent a person from donating.
• Heart Disease: A history of heart attack, major heart surgery, or other significant heart conditions is typically a disqualifier.
• Diabetes: Individuals requiring insulin or injectable medication for diabetes are not eligible.
• Infectious Diseases: Infections like HIV and chronic hepatitis B or C are grounds for exclusion.
• Severe Respiratory Conditions: Severe asthma, sleep apnea, or emphysema can prevent donation.
• Chronic Pain: Severe, chronic back or neck problems can be a disqualifier.

The Critical Role of HLA Typing

Compatibility between a donor and a recipient is determined not by blood type, but by a close match of Human Leukocyte Antigen (HLA) markers.

• What are HLAs? These are proteins on the surface of most cells that help the immune system recognize which cells belong to your body. We inherit these markers from our parents.
• Finding a Match: The more markers that match between a donor and a patient, the higher the chance of a successful transplant. Because HLA types are so diverse, especially among different ethnic groups, a larger and more diverse donor registry increases the odds for all patients.

The Step-by-Step Donation Process

1. Register: Potential donors join a registry by completing a health questionnaire and providing a cheek swab or blood sample for HLA typing.
2. Match Notification: If your HLA type closely matches a patient in need, the registry will contact you. This can happen years after you register.
3. Medical Screening: You will undergo further blood tests and a thorough physical exam to confirm you are the best match and medically cleared to donate.
4. Informed Consent: You will have a consultation to discuss the procedure, risks, and side effects before signing a consent form.
5. Donation: You will donate via either peripheral blood stem cell (PBSC) collection or bone marrow donation.

Peripheral Blood Stem Cell (PBSC) vs. Bone Marrow Donation

The patient's physician determines the best collection method for their specific needs.

Feature	Peripheral Blood Stem Cell (PBSC)	Bone Marrow Donation
Procedure	Non-surgical, similar to a platelet donation (apheresis). Donor receives daily injections of filgrastim for 4-5 days beforehand to increase stem cells in the bloodstream.	Surgical procedure under general or regional anesthesia. Marrow is collected with needles from the pelvic bone.
Duration	4-8 hours per day, typically for 1-2 days.	1-2 hours in the operating room.
Recovery	Most feel back to normal within a day or two. Common side effects include bone or muscle aches from filgrastim, which subside after donation.	Most donors go home the same day. Full recovery may take a few weeks. Side effects include pain in the hip/pelvic area, bruising, and fatigue.

The Growing Need for Diverse Donors

Due to the genetic nature of HLA, a patient's best chance for a match is with a donor who shares a similar ethnic background. Unfortunately, patients from diverse ethnic communities are significantly underrepresented in donor registries worldwide. Increasing the number of diverse donors is a crucial step toward ensuring all patients have an equal chance at finding a life-saving match.

Dispelling Common Myths

• Myth: Donation is extremely painful. The PBSC procedure (used in 90% of cases) is not surgical. While filgrastim can cause temporary bone aches, it is not severe pain. Bone marrow donation is surgical, but performed under anesthesia with pain managed afterward.
• Myth: Only males can donate. Eligibility is not determined by gender, and any healthy adult who meets the guidelines can donate.
• Myth: Donation is dangerous. Donors are closely monitored and screened to ensure their safety. The body naturally replaces the donated cells.

Your Commitment as a Potential Donor

By joining a registry, you are making a commitment to be available to save a life. While the odds of being called are low, being prepared to proceed if matched is a serious responsibility. Many registries offer resources and support for donors, covering travel expenses and lost wages during the process.

Conclusion

Understanding what are the requirements for stem cell donation is the first step toward becoming a potential life-saver. Meeting the age and health criteria and registering with a reputable organization like NMDP or DKMS can add you to a global pool of potential donors. For those in good health, this act of generosity can make an immeasurable difference to a patient and their family. You can learn more about registering to become a donor with the National Marrow Donor Program (NMDP) on their website.

Frequently Asked Questions

What is the age limit for registering to become a stem cell donor?

Most registries, such as NMDP (formerly Be The Match), focus on recruiting donors aged 18 to 40 because research shows younger donors provide the best outcomes for patients. Some organizations may accept donors up to 60 for specific circumstances.

What health conditions prevent someone from donating stem cells?

Disqualifying conditions include most cancers, chronic autoimmune disorders (like lupus or rheumatoid arthritis), serious heart or lung disease, HIV, and insulin-dependent diabetes. A full health screening is required if you are identified as a potential match.

Does my ethnic background affect my ability to donate?

Your ethnic background doesn't affect your ability to donate, but it does play a significant role in matching. Patients have a higher chance of finding a match within their own ethnic group due to genetic HLA markers, making diverse donor registrations extremely important.

Is stem cell donation a painful process?

Not necessarily. Most donations are done through the PBSC method, which is similar to a blood draw and has a mild, temporary recovery period. Bone marrow donation is surgical and involves anesthesia to minimize pain during the procedure, with some soreness expected afterward.

Is there a weight or BMI restriction for donation?

Yes, some registries have a BMI limit to ensure donor safety. For example, some may not allow individuals with a BMI over 40 to register. This is assessed during the health screening process.

Do I have to pay to register or donate?

No, all medical costs associated with the donation process, from registration to the procedure itself, are covered by the recipient's insurance or the donor registry. This includes travel, meals, and lodging if required.

What is the difference between bone marrow and PBSC donation?

The main difference is the collection method. PBSC donation collects stem cells from your blood after injections to increase their count. Bone marrow donation is a surgical procedure to collect marrow from your pelvic bone while you are under anesthesia.