Which blood tests will be conducted to determine whether a recipient and potential kidney donor are compatible?
There are three principal blood tests which will establish whether a recipient and a potential kidney donor’s blood, are compatible for a kidney match. These tests are: blood typing; tissue typing and crossmatching. Read more what do kidney stones look like
What is ABO Compatibility (Blood typing)?
The initial blood test, which will establish your blood’s compatibility with that of the potential donor, is blood typing. Antibodies which respond with various blood groups, are measured by this test.
Should the donor’s blood type matches with your blood-type, the second blood test, tissue typing, will be taken by the donor. However, the Rh factor (plus or minus) is not important. Below are the blood types which are compatible:
Blood type A donors can donate a kidney to blood types A as well as AB recipients
Blood type B donors can donate a kidney to blood types B as well as AB recipients
Blood type AB donors can donate a kidney only to blood type AB recipients
Blood type O donors can donate a kidney to blood types A; B; AB as well as O recipients. The O blood type donors, are known as universal donors, because their blood type is compatible with all other blood types
Blood type O recipients can only receive a kidney donated by blood type O donors
Blood type A recipients can accept a kidney donated by blood types A & O donors
Blood type B recipients can accept a kidney donated by blood types B & O donors
Blood type AB recipients can accept a kidney donated by blood types A; B; AB & O donors. The AB blood type recipients, are called universal recipients, because their blood type is compatible with all other blood types.
However, in instances where blood types are incompatible, a potential donor will still be able to donate a kidney directly to you. Treatments are administered which lower your level of blood antibodies. However, a donor may contemplate to donate via a paired exchange-program. This can enable you to receive a kidney, donated by another donor whose kidney is not compatible with that of the intentional recipient. Discuss this with your transplantation coordinator who can render support and supply you with additional information.
Tissue typing: A short description
The first blood-test establishes the recipient’s HLA tissue type as well as that of the potential donor determining the degree of compatibility. Every individual’s tissues, with the exception of identical twins, are normally different from that of everybody else’s. It is the opinion that how higher the quality of the HLA match is, the higher the chances of a successful transplant, which can last for an extended period of time. A parent and a child will have no less than a 50% chance to match. This is due to the process how DNA/chromosomes are passed down or inherited in the family. Siblings may have a zero – 100% match, whilst unrelated donors may have less or no chance of matching.
The most effective match for a recipient is having a 12-out of s12antigen-match. It is achievable that each of the 12 markers can match. even if it is a kidney from a deceased, unrelated donor, providing that the patient has a highly common HLA-type. This is called a zero mismatch.
Antibodies to HLA is measured by the other blood test and is only conducted for the patient, which is repeated on a frequent basis. Often it is done monthly, but in some instances less frequent, which will depend on the policy of the transplant program. The HLA’s antibodies can cause harm to the new kidney and can escalate or decline with time. Therefore, measuring should be done while the recipient is waiting for the transplantation, immediately prior to the surgery and sometimes after the transplant surgery.
When HLA antibodies are found in a recipient’s blood, the patient is
considered to be HLA sensitized. In such cases it is better to seek for
a donor with the HLA types which evade the HLA-antibodies in the
It is important to take into account, that HLA antibody levels may change after certain occurrences like miscarriages, blood transfusions, severe infections and minor surgeries, which also include a fistula replacement and dental work. The patient should inform the nurse coordinator about these kinds of occurrences.
PRA (Percent Reactive Antibody): A description
While you are evaluated for your kidney transplant you will hear the term, PRA a lot. With exposure to foreign tissues via a prior transplant, pregnancy or blood transfusion, an antibody may develop to various HLA proteins. In the event that you are positively tested for HLA-antibodies, they will deem you as sensitized, whilst your PRA-percentage will be more than 0. How higher the HLA-antibodies in your bloodstream, the more your PRA-percentage will be. However, it is vital to be tested for the existence of such HLA-antibodies, prior to your kidney transplant. With a high number of HLA-antibodies a compatible kidney can be rather difficult to find. Due to new procedures like plasmapheresis, antibodies can be decreased in the blood. However, HLA-antibodies can differ over time, whilst your PRA-percentage can change too.
Serum crossmatch: A description
It’s a blood test which both the recipient and donor will have numerous times, even immediately prior to the transplant surgery. During a serum crossmatch, your serum will be mixed with cells coming from your donor. Should your serum contain antibodies towards the cells of the donor, antibodies will bond the donor’s cells, which can be detected by using a technique of fluorescent detection.
A high quantity of antibodies will destroy the donor cells. The process is called positive crossmatch, which means that the kidney transplant must be cancelled. Should the transplant continue, it would lead to the instant rejection of the new kidney.