Bone marrow donation is a medical procedure that provides healthy blood-forming stem cells to patients with life-threatening diseases such as leukemia, lymphoma, and other blood disorders. This process offers a chance at recovery for individuals whose own bone marrow is not functioning properly.
Understanding Age Requirements
Age requirements for bone marrow donation are specific and vary by registry. The National Marrow Donor Program (NMDP), also known as Be The Match, accepts individuals aged 18 to 40 to join their registry. While the upper limit for joining is often 40, some registries keep donors listed until age 61, and others like DKMS accept registrations up to 55 years old. The minimum age of 18 is consistent across registries, as donors must provide informed consent.
Healthcare professionals prefer donors aged 18 to 35 years due to better outcomes for recipients. This preference is based on research indicating that younger donors contribute to more successful transplant outcomes.
Other Important Eligibility Considerations
Beyond age, other factors determine eligibility, focusing on the health and safety of both the donor and recipient. Donors must be in good general health, free from severe chronic conditions or infectious diseases. Disqualifying conditions include HIV/AIDS, hepatitis B or C, severe heart, lung, or kidney diseases, and many forms of cancer.
Weight and Body Mass Index (BMI) also play a role, as extreme underweight or overweight conditions can pose risks for the donor or affect donation success. Certain autoimmune diseases, if well-controlled and not affecting multiple organ systems, might allow for donation after careful evaluation.
What Happens During Donation
There are two primary methods for collecting blood-forming stem cells for transplant: peripheral blood stem cell (PBSC) donation and bone marrow donation. PBSC donation is the more common method, accounting for approximately 90% of all donations. This non-surgical outpatient procedure involves the donor receiving daily injections of a medication called filgrastim for five days before donation. Filgrastim stimulates the bone marrow to produce more stem cells and release them into the bloodstream.
On the day of PBSC donation, blood is drawn from one arm and passed through a machine that separates out the stem cells, with the remaining blood returned to the other arm. This process, called apheresis, typically takes four to eight hours. Bone marrow donation, on the other hand, is a surgical procedure performed in an operating room, usually under general anesthesia. Needles are inserted into the back of the pelvic bone to draw out the liquid marrow, a process that generally takes one to two hours. Donors may experience some soreness or discomfort at the collection site afterward.
The Importance of Donor Age
The age of a bone marrow donor significantly impacts the success of a transplant for the recipient. Research consistently shows that stem cells from younger donors lead to better long-term survival rates for patients. This is because younger donors tend to have more robust and viable stem cells, which are crucial for the engraftment and recovery of the patient’s immune system. Studies have found that younger donors are associated with less graft-versus-host disease (GVHD) and improved overall and disease-free survival in recipients.
As individuals age, their stem cells can experience changes, such as a decline in vitality and shorter telomeres, which are structures at the ends of chromosomes. Shorter telomeres mean cells have fewer divisions remaining, potentially limiting the long-term function of transplanted cells. Additionally, older donors may have a higher likelihood of underlying health conditions that could impact the donation process or the quality of the donated cells.