Eight hundred transplants facilitated through the Highly Sensitized Patient program

August 9, 2022

We are pleased to share the news of another exciting milestone for the Highly Sensitized Patient program.

The Highly Sensitized Patient (HSP) program is a national organ sharing program operated by Canadian Blood Services in collaboration with all provincial donation and transplant programs The program gives provincial transplant programs access to a larger national pool of kidney donors for highly sensitized patients who need a more specific donor match.

The implementation across Canada began in October 2013 and by November 2014, all provinces and territories had joined the HSP program. 

What does being highly sensitized mean?

Highly sensitized means that the patients have a sensitized immune system. Immune system sensitization may be a result of blood transfusions, previous transplants or pregnancies, which is why many highly sensitized patients are women. As a result, patients who are “highly sensitized” are at higher risk of rejecting an organ transplant. This makes it very difficult to find a suitable donor match.

Our bodies are designed to attack what’s foreign, that’s how our immune system works to fight off viruses. The more antibodies to different HLA proteins the patient has, the fewer donors from whom they’ll be able accept an organ.

How does the program help sensitized patients?

The HSP program makes it more likely that people who need a kidney transplant, and are hard to match, will find one. The program uses sophisticated technology to match the right kidney to the right patient anywhere in Canada with accuracy and efficiency. An organ matched through the HSP program reduces the risk of potential rejection. This means highly sensitized patients have improved chances that:

  • their body will accept the new organ;
  • the organ will last longer; and
  • they will not end up back on a waitlist.  

The collaboration with provincial testing laboratories is part of the national advisory structure organized by Canadian Blood Services, unique to Canada, and is foundational to the success of the program. 

The cPRA (calculated panel reactive antibody) calculates the list of antibodies in a patient and runs an algorithm to estimate the number of potential donors in the population. Some organ transplant candidates, especially those who have already been exposed to “foreign” tissue (through previous transplant, pregnancy, or blood transfusion), will have an immune system already primed to reject organs from donors with certain antibodies present. 

Doctors do HLA testing while patients are waiting for transplants. Once they figure which antibodies, and how many the patient has, they can use the cPRA calculator to estimate what that means in terms of getting a transplant.

Why was the HSP program developed?

Approximately 20 per cent of patients on provincial waitlists are highly sensitized and in need of a kidney transplant. Yet, these same patients historically receive less than one per cent of available organs. With access to a limited number of donors in their home province, highly sensitized patients wait much longer for a kidney transplant and have a greater chance of becoming more ill or dying while they wait. By providing access to donors across the country, the HSP program increases the chances of finding kidney transplants for these hard-to-match patients. 

Quick Facts

  • The HSP program is for patients needing very specific matches from deceased kidney donors. Through the HSP Program, this group of patients now has access to a larger national donor pool, dramatically increasing the chance of a match.
  • Women are disproportionately highly sensitized due to antibodies developed during pregnancy.
  • More than 4,100 people are waiting for organ transplants in Canada today; however, only a fraction of Canadians are registered to donate. While many Canadians are aware of the need for organ transplants, there remains a shortage of donors.
  • Each year approximately 250 Canadians die while on a waitlist.

One organ donation can save up to eight lives; tissues can save up to 75 lives. Register your intent to become an organ and tissue donor, talk to your family about your decision to donate and ask them about their wishes. Find out how to register where you live at: organtissuedonation.ca