What is an Unrelated Donor?

In organ, blood, and bone marrow donations, if a compatible donor cannot be found from relatives, transplantation can be made from people who are not related but have blood and tissue compatibility. Transplanters with whom we are not related by blood are called unrelated donors.

Who Can Be an Unrelated Donor?

Screening is initiated in voluntary donor banks if a suitable donor is not found within the family. These voluntary donors are called “non-kin donors.” Persons with the same blood group or compatibility in organ and blood transplants can be unrelated donors. The only condition is not blood group compatibility. If there is a match in the required compatibility and tissue tests, transplantation from unrelated donors can be performed.

O Group Only O Group can give
Group A Group A or Group O
Group B Group B or Group O
AB Group Any group can give (O, A, B, or AB)


For bone marrow transplantation, the blood group of the recipient and the donor does not need to be the same. Transplantation can also be done between people with different blood types. What matters is how similar the tissue group antigens are between the patient and the donor (recipient and donor). Tissue compatibility is among the factors that directly affect the success of transplantation.

In tissue incompatibility, the risk of developing a condition called “graft versus host disease” GVHD increases. In GVHD, a war begins between the donor’s defense cells and the patient’s tissues and organs after transplantation. The patient’s organs and tissues can be seriously damaged in this case. Therefore, individuals with tissue compatibility with the patient may be unrelated donors.


What are the Conditions to Become an Unrelated Donor?

It accepts every healthy person between 18 and 50 and weighing at least 50 kg as a stem cell donor.

Voluntary bone marrow/stem cell donor candidates should not have infectious, immune system, or infectious diseases.

For this, first of all, blood samples are taken from the donor candidates and examined. If no disease is detected, the tissue type is determined, and your information is transferred to the bone marrow bank.

If it is determined that you are compatible with one of the patients who applied to the bone marrow bank and are waiting for transplantation, you will be contacted, and your donation method will be selected.