February 09, 2005

Heritage can create transplant hurdles

By Erin Texeira
Associated Press
January 31, 2005

Luke Do was a lively 18-month-old awaiting the birth of his first sibling when he was diagnosed with a rare form of leukemia.

The hopes of his parents, both doctors in San Jose, Calif., immediately turned to a bone marrow transplant, but they soon learned some distressing news -- Luke's ethnic heritage made him a tough match.

Sarah Gaskins, Luke's mother, has Japanese and European ancestors and his father, Lam Do, is Vietnamese-American. Because bone marrow matches usually are made with a relative or someone with the same racial or ethnic background as the patient, multiracial people rarely have success.

"It's tragic," said Lam Do, who specializes in internal medicine. "Your chance of finding a donor is so low, it's like winning the lottery."

For years, the medical community has pushed for increased donor registry among racial minorities to improve survival rates for leukemia, lymphoma and other blood diseases. But to the general public, the situation is not well-known.

Only 2 percent of those who list their ancestry with the National Marrow Donor Program are multiracial, though the NMDP will -- for the first time -- study multiracial patients' medical records this year to better understand what kind of marrow tissue they tend to inherit from their parents. The group also will try to recruit potential donors more effectively, said Helen Ng, an NMDP spokeswoman.

Matt Kelley, president of Mavin Foundation, a Seattle-based advocacy group for multiracial people, says the inattention to the problem reflects society's reluctance to accept today's increasingly complex racial landscape.

"It's a headache," said Kelley, whose group has an ongoing bone marrow program. "The reality is that many organizations are afraid of addressing race . . . and when it comes to addressing mixed-heritage issues, they don't want to go there."

Today, whites in need of a bone marrow transplant have about a 90 percent chance of finding a match, said Dr. Patrick Beatty, an oncologist with the Montana Cancer Specialists in Missoula, Mont. For those who aren't white, "your chances of getting a match are pretty remote," he said.

The biological reason has to do with the body's response to infections, Beatty said. Because the world's ancient peoples were exposed to different diseases over millennia, each group developed different tissue antigens, substances that help fight illness.

Descendants retain those highly varied tissue antigens, he said, making it tough to match the bone marrow of individuals from different ancestries.

Luke Do's family was elated when, about six months after his diagnosis, they learned a match had been found in a Japanese-American police officer in Seattle.

Now the Dos are making plans for Luke to start kindergarten -- and to celebrate the third anniversary of his transplant on March 18.

Nationwide, census data counted about 7 million people of multiracial heritage -- the first time an option was available to check more than one racial category. Mavin organizers estimate the true number is closer to 10 million.

Within that group, there are millions of possible ethnic mixes, and therefore millions of potential challenges for someone seeking a bone marrow match. Complicating the situation further, research shows that minorities have greater tissue variation than whites. Africans and their descendants globally have the most variation of any population in the world, "many, many more tissue types than Caucasians," Beatty said, adding that current research is focusing on finding matches with umbilical cord blood and developing matching tissues.

"Many (multiracial) people have very little contact with entities that recognize them correctly," said Kelley of Mavin, adding that this typically results in hurt feelings and a sense of social isolation. "We don't have that luxury when it comes to people's health."

Link (Indianapolis Star)

No comments: