A microscope slide of bone marrow.
A microscope slide of bone marrow. Credit: jilldoughtie / Flickr

If you become ill with a blood cancer or another disease that requires a stem cell transplant, your racial background could affect the likelihood of finding a viable genetic match for bone marrow or cord blood.

In an effort to increase the diversity of matching donors in the San Antonio area, the city on Saturday will host the largest coordinated World Marrow Donor Day, an international effort to increase the number and diversity of donors on the global registry.

“It is very important that we get a very diverse population to join the registry because a person is much more likely to find a match with someone of your own ethnicity,” said Monica Reyes with BioBridge Global, the nonprofit overseeing GenCure, an organization promoting the development of cell and tissue-based therapies that coordinated the local donor drive. “There are hundreds of Texans currently searching for a marrow donor.”

According to the National Marrow Donor Program, white people have the highest chance of finding a match at 97 percent, with Latinos at 80 percent, Native Americans at 77 percent, Asians at 72 percent, and blacks at 66 percent.

San Antonio is home to the first Hispanic bone marrow donor in the nation, Reyes said, noting that the local registry now has more than 250,000 people from 60 counties in the region – 80 of whom come from ethnically diverse backgrounds. When Ralph Morales donated in 1993, only about 7 percent of donors on the registry were Hispanic, Reyes said.

GenCure, in partnership with the National Marrow Donor Program and H-E-B, will host marrow donor registration drives at 16 H-E-B locations throughout San Antonio from 10 a.m. to 4 p.m. on Saturday, though those interested can text Cure44 to 61474 to pre-register. Potential donors must be between the ages of 18-44, in general good health and have no history of or current serious illnesses. After a screening, donors will give either a blood donation or a swab of cheek cells, and the results then will be entered into a national registry of people around the world who have agreed to donate. Contact information will be made available to medical providers.

Currently, only 2 percent of the population is on the national registry.

Blood cancers are the third leading cause of cancer deaths in the United States with a new diagnosis approximately every three minutes, according to the Leukemia and Lymphoma Society. For many patients, a bone marrow transplant is the only cure.

“It’s important to get as many people on the registry as we can because even though [registry] numbers have risen, about 50 percent of the folks who join will back out of their donation,” Reyes said.

A bone marrow transplant takes a donor’s healthy blood-forming cells and puts them into the patient’s bloodstream, where they begin to grow and make healthy red blood cells, white blood cells, and platelets. For a successful transplant, donor and recipient must have nearly identical genes regulating certain immune cells, but only 30 percent of people find a match in their family, meaning 70 percent rely on strangers to donate.

At any given time, about 7,500 Americans are actively searching the national registry for an unrelated donor, according to the National Marrow Donor Program. All in all, nearly 3,000 die every year because they cannot find a match.

Roseanna Garza reports on health and bioscience for the San Antonio Report.