Ancestry Matters When Seeking Matched Bone Marrow Donors

WEDNESDAY, March 27, 2019 (HealthDay News) -- The chances of finding an unrelated bone marrow donor are higher for U.S. patients of European descent than for those of non-European descent, a new study finds.

A bone marrow transplant can sometimes help people with life-threatening blood cancers by replacing the patient's cells with healthy ones from a donor. A brother or sister with the same genetic markers as the recipient is the ideal donor.

For patients without a suitable sibling donor, a transplant from a matched unrelated donor is typically the next best option.

In the new study, researchers looked at just over 1,300 blood cancer patients at Memorial Sloan Kettering Cancer Center, in New York City, who sought a fully matched bone marrow donor between 2005 and 2017.

While 67 percent of patients with European ancestry received a matched transplant from an unrelated donor, the rate was only 33 percent for non-Europeans, including Asians, white Hispanics and Africans. Those of African descent had the lowest rate.

But not all Europeans had equal success: 41 percent from southern Europe had a fully matched donor, compared to between 64 percent and 77 percent of others, according to the study published online March 27 in the journal Blood Advances.

Most who did not have a full match either received a partial match (17 percent of all patients) or a cord blood transplant (24 percent), according to the study. Four percent of patients did not receive a transplant -- the majority of these patients were of African descent.

"We have identified tremendous racial and ethnic disparity in transplant access," study author Juliet Barker said in a journal news release. "What's more, it has been thought by some that if you just increase the number of registered adult donors that it would resolve this problem, but it hasn't."

Barker, director of the Cord Blood Transplant Program at Memorial Sloan Kettering, said the findings show the importance of efforts to improve outcomes of alternative donor transplantation, including the use of unrelated donor cord blood.

Although experts knew that non-European patients have trouble finding a match, the difficulty for patients with origins in southern Europe hasn't been widely appreciated, Barker said.

Transplant centers have the technology to quickly gauge a patient's chances for a matched donor and should abandon futile adult donor searches and donor drives if chances are poor, she said. "This is more and more important as our population increasingly becomes more diverse," Barker concluded.

More information

The National Marrow Donor Program has more on bone marrow transplant.