Canada’s Stem Cell Registry Is Super White, and Changing That Would Save Lives

Multi-racial blood disease patients face especially terrifying odds when searching for stem cell donors with matching genes.

|
Sep 25 2016, 2:00pm

Aaryan and Jenny Dinh. Photo via Facebook

Finding out your kid has a rare and deadly blood disorder is scary enough, but for Jenny Dinh, there was extra bad news.

Her 11-year-old son Aaryan Dinh-Ali was diagnosed with aplastic anemia in November last year, which meant his body wasn't producing enough blood cells. What started as a few mystery bruises and bleeding gums after brushing his teeth escalated to internal bleeding in his brain, requiring constant blood transfusions just to stay alive.

Doctors told Dinh a stem cell transplant could potentially cure her son's condition, but no donors matched with Aaryan's genes. Then she heard that Aaryan's racial background was part of what made the transplant inaccessible.

"My learning process was a hard one," Dinh told VICE. "Doctors said there was no match for Aary, we had to put him on a drug therapy. We just had to hope and wait to see if the meds would work."

In Canada and in most of the world, race really affects how likely you are to find a matching stem cell donor. I didn't know this, but stem cell transplants have nothing to do with blood type, they actually require near-identical genetic markers so that the body doesn't reject the new cells. Apparently donors with the same ethnic and racial backgrounds are far more likely to match, though that's not a guarantee. Even siblings only have a 25 percent chance of matching.

If Dinh and her partner Khalid Ali were white, Aaryan's story would probably be different. Dinh's family is Vietnamese, and Ali's background is Afghani, which means there are exponentially fewer chances of finding a donor. In Canada, the chances of a white person finding a non-sibling match is over 90 percent. That drops way down for Asians and Middle Easterners, and can become a one-in-a-million gamble for some multiracial patients like Aaryan. "It's like finding a needle in a haystack, but the haystack is the biggest you could ever imagine," Dinh told VICE.

Though the numbers are slowly shifting, Canada's stem cell registry still underrepresents many non-white groups, including Black, Indigenous, Filipino and South Asian people. According to the Canadian Blood Services' own data, 29 percent of registered donors are "ethnically diverse." That's up from 28 percent last year.

"I don't think people are aware of the pie chart—they don't understand that if you're white, this is your chance, and if you're Asian, you don't have this chance," said Dinh.

Doctors in the field recognize the whiteness built into Canada's stem cell donation system. As Dr. Dana Devine of Canadian Blood Services puts it in an upcoming Vancouver International Film Festival film called Mixed Match, "We tend to have a rather Caucasian view of the world, because that's where the HLA [human leukocyte antigen] science came from originally. There were a lot of Europeans doing this kind of work, and it was a little bit limited in its view."

Canadian Blood Services regularly recruits donors on campuses, and has partnered with some South Asian, Chinese, Filipino and First Nations organizations on stem cell drives. But the registry has further to go before it reflects what Canadian society looks like. "We're trying to grow it to the 60-40 mark, which is more representative of Canada," British Columbia's stem cell territory manager Trudi Goels told VICE. When asked how much funding goes into recruiting non-white donors, a spokesperson said those numbers aren't readily available.

Umbilical cord blood, a relatively new source of stem cells in Canada. Still courtesy of 'Mixed Match'

It's possible that future technological shifts may make race less relevant to stem cell treatment. In the last few years, Canadian Blood Services started collecting umbilical cord blood donated by new parents, which can be used with more forgiving DNA requirements in some cases. The first-ever cord blood transplant on a Canadian patient happened earlier this month. But for the 790 patients currently on the stem cell waiting list, waiting for a breakthrough isn't always an option. "They're there to help save lives, but more focus needs to be put on diversifying," said Dinh.

In Aaryan's case, Dinh says she's thankful that immune-suppressing drugs have mostly worked, which means he's been transfusion-free for a few months now. But long-term, his best option is still to find a donor with a genetic match, which is why families like Dinh's are increasingly part of Canadian Blood Services' efforts to "diversify" its stem cell registry.

Dinh finds most people don't know how the registry or stem cell donation works. She says she'll often have to go over the basics: yes, they take a DNA sample from your cheek, no, they don't take anything out of your spine. (Though some marrow procedures do tap your hip bone).

On Thursday, I went down to Burnaby's city hall and got my own cheek swabbed, at an event hosted by Aaryan's uncle, who works for the city's RCMP detachment. Since they started a website to find a match for Aary, Dinh says they've helped push 5,000 people to sign up.

"It sounds like a lot of people, but to be honest it's not," said Dinh. "From what I know, Canadian Blood Services has only registered one to two percent of people in the stem cell registry. It's not enough.

"Honestly I believe every person has a match somewhere."

Follow Sarah Berman on Twitter.