Research Award Recipients

Addressing inequity in access to kidney transplantation with Canadian innovation in ABO histocompatibility

Co-applicant(s): Esme Dijke, Sita Gourishankar

Lay Abstract

Background: Kidney transplants improve the health and quality of life in patients whose kidneys are not functioning. Receiving a kidney transplant offers a life free from dialysis. To have the best chance at a successful transplant we must consider compatibility between the patient and the donor. This compatibility includes ABO blood group. The ABO system includes ABO-A, B, O and AB markers. These markers are sugars that ‘decorate’ cells and tissues, including kidneys. ABO compatibility is a bigger problem for patients who are blood group ABO-O or ABO-B and they wait longer to be transplanted as they are compatible with fewer donors than ABO-A and ABO-AB patients. To provide more transplant opportunities for ABO-O and B patients, we can do ABO-incompatible transplants which includes laboratory testing to make sure that the transplant is safe. The current lab tests were developed in 1901 and have many problems.

Purpose: We designed a modern test to measure ABO antibodies that provides a more true assessment of ABO compatibility. We can combine this new antibody test with other new tests that use DNA to tell us more about the blood group of the donor. Our goal is to make access to kidney transplant fairer across all the ABO groups.

Methods: We have developed a modern way to measure ABO antibodies by attaching ABO sugars to small plastic beads. We have shown that this way of measuring these antibodies can find more compatible patient and donor pairs. We are now going to be using this new test within the Canadian kidney paired exchange registry in combination with the old test to show that we can start to use this new innovation to benefit Canadian kidney transplant patients. We will work with clinical laboratory and other partners across Canada to complete this project. We will also use new DNA tests to make sure that the blood group typing of donors is defined as accurately as possible. We have also added one more way to check for ABO compatibility. We mix red blood cells from the kidney donor with the blood of the patient and then check for reactivity between these two individuals. This final personalised way of testing a donor-recipient pair will add a new level of certainty that the patient is unlikely to reject the donor kidney . All these tests can be easily done by the transplant compatibility laboratory which already performs similar types of tests for other purposes and has all the instruments ready for use.

Anticipated Outcomes: We have already reported that the old way of measuring compatibility for an ABO mismatched transplant is too limiting. We predict that by using our improved ABO compatibility testing we can find more ABO-O and B patients who can be safely transplanted with shorter wait times. This project is very well timed as the Canadian Transplant Registry will be adding ABO-incompatible transplants to our national program next year.

Patient Engagement: We will work with patient and donor partners from the Canadian Donation and Transplant Research Program. We will have a budget to compensate partners for their time away from work and family. Patient partnership will be critical to interpretation of results and to share this new information back to the transplant community in the most effective way. Their expertise will enrich our study progress and the success of increasing access to ABO incompatible transplants in Canada. The lead scientist in this project is also a living kidney donor and is strongly motivated to make sure that we use donor kidneys in the best possible way.

Relevance to Patients/Community: Access to transplants should be as fair as possible. But we know that patients with the ABO blood groups of ABO-O and ABO-B have fewer compatible donors than patients who are blood group ABO-A and ABO-AB. These new blood tests to measure ABO compatibility have the potential to improve access to transplant for more patients.

Conclusion: We can overcome ABO inequity in transplantation by performing ABO-incompatible transplants. But our current way to measure ABO compatibility is limiting access to this option. Transplant laboratories already have the tools they need to use our new ABO compatibility tests and provide improved safe access to kidney transplantation for all ABO blood groups.