Matching kidneys for organ donation is a complex process. Tissue and blood types are tested to see if they’ll work together. Many tests are done to make sure the kidney is healthy and that it’s working well before a match is made.
Kidneys are matched based on blood type. The process of matching donor blood types with your blood type is known as crossmatching. The following chart shows which blood types are compatible or can be used together. If your blood type doesn’t match the donor’s blood type, you won’t be able to get a kidney from that person directly. But you still may be able to receive a kidney transplant from another donor or possibly through the
Kidney Paired Donation program.
Your blood type
You can receive a kidney from blood type
| A or O
| B or O
| AB, A, B, O
If a match is found from a deceased donor, it will likely be from a person with your blood type.
Having a compatible blood type is only one part of knowing if you’ll be a match. You can still donate your organs even if you don’t belong to a compatible blood type. Your Rh factor, which is tested for with blood typing, is only one part of the matching process.
To find out more about blood type testing go to
Blood type test or
What is my blood type?
Canadian Blood Services data shows that in Canada, the following percentages make up each of the 4 blood groups. Type O is the most common and type AB is the least common.
- type O – 46%
- type A – 42%
- type B – 9%
- type AB – 3%
Immune system tests
Your immune system protects your body against anything that doesn’t belong to you, like a cold or flu virus. These are called
antigens. Your body will attack the virus and try to destroy it by making antibodies against the virus. These antibodies stay in your body so the next time that same virus attacks, your immune system will remember the virus and make more of these antibodies to start an attack against it. This means your immune system gets sensitized to those viruses.
Your body can also make antibodies against blood or tissue from a blood transfusion, organ transplant, or from being pregnant. A kidney won’t be a match if your body makes antibodies against the donor’s kidney.
For an organ transplant to work, you will need to have human leukocyte antigen (HLA) testing as well as antibody testing. HLA refers to genetic markers you get from your parents. These tests show if your body will make antibodies against the donor’s HLAs. If your body makes antibodies against the donor’s HLAs, it will likely attack the transplanted kidney and reject it. This is called being sensitized.
You will have blood tests to measure how many different HLA antibodies you have in your blood. In general, the higher number of HLA antibodies in your blood, the harder it will be to find a donor kidney that your body won’t reject.
Calculated panel reactive antibody
The calculated panel reactive antibody (cPRA) is screening test to find out how likely it will be to find a potential donor match. The cPRA is based on how many HLA antibodies you have and is given as a percentage. For example, if you have a cPRA of 80% then your HLA antibodies will work against 80 out of 100 potential donors. This means that you’ll likely have to wait longer to find a match.
People with a cPRA of 95% or higher are called highly sensitized. They have a much harder time finding a match so they are eligible for the
Canadian Blood Services’ National Highly Sensitized Program. This program aims to match people to donors who have passed away (called deceased donors) from across the country.
What is kidney paired donation?
If you have a living donor, but that person’s kidney is not a match for you, you can still have a living kidney transplant. Your donor will be able to donate, but not directly to you. You will receive a donated kidney from a different donor.
Your transplant program can register you and your donor in the
Kidney Paired Donation (KPD) Program. It’s a national program that matches living donors and recipients across the country. Local living donor programs register donors and recipients for this national program. Canadian Blood Services operates this program and works together with kidney transplant centers across Canada.
To find out more about KPD go to
Types of living donation.