Helen Branswell, The Canadian Press Published Friday, May 22, 2015 12:10PM EDT
The program is designed to assist people who are “highly sensitized,” meaning they already have high levels of antibodies to foreign tissues.
These patients are very likely to reject donor kidneys unless there is a close match between them and the donor tissue, but making that match has proved to be a tough thing to do.
Highly sensitized patients make up about 20 per cent of the people waiting for kidney transplants, but historically they have received less than one per cent of the kidneys transplanted in this country.
The new program, operated by Canadian Blood Services, has created a national system for highly sensitized patients.
In the past, these people would need to wait for well-matched kidney from within their own province; now they will be eligible to get donor organs from any part of the country, if the organ is a good match.
That has required adopting a standardized laboratory testing method for tissue matching across the country as well as computer systems that can share information across provinces.
“Until this program we were really not shipping kidneys anywhere — because we couldn’t identify the need,” says Dr. Peter Nickerson, who is the medical director for Transplant Manitoba and also serves as medical adviser for donation and transplantation for Canadian Blood Services.
“So now we’re basically saying instead of an individual in Manitoba who only has access to the Manitoba donor pool, they now have access to the entire Canadian donor pool. Because they’re so difficult to get transplanted.”
The Highly Sensitized Patients program was rolled out Friday at a press conference in Winnipeg. But while this was the public launch, the system has been gradually coming online for some time. The first provinces joined in October 2013 and all provinces were enrolled by November 2014.
To date, 111 hard-to-match people have received kidney transplants through the program. While the program currently only operates for kidneys, there are plans to expand it to other solid organ transplants in future.
People who are highly sensitized have already been exposed to foreign tissue or proteins and have developed high levels of antibodies to protect against what their immune system sees as invaders. Even with the immune suppression drugs transplant recipients take, highly sensitized patients will reject all but the best matched donor kidneys.
People can become highly sensitized if they have already had an organ transplant, or sometimes even blood transfusions.
The majority of highly sensitized people are women. That’s because during pregnancy women become exposed to proteins from their fetus’s father. Nickerson says that a woman who has had one pregnancy has a 10 per cent chance of becoming highly sensitized. After three pregnancies, the rate goes up to 30 per cent.
“For most people that just doesn’t matter because you’re not likely to need a transplant. But if you do need a transplant that becomes a real barrier for you finding a compatible donor,” he says.
People who need a kidney transplant can wait between three and eight years for one to become available, says Nickerson. But for highly sensitized people “trying to find that match can take a long time.”
He says in the past some of these patients have waited 16 years or longer for a suitable organ, having to rely in that interval on dialysis.