Who can be a donor for kidney transplantation?
A kidney from a deceased donor comes from a person who had brain death. A person who has given consent to organ donation for transplantation at the time of death or whose families provide such permission can donate their kidneys to a person in need. The kidneys are evaluated for transplantation, and if healthy, they are removed and stored until an appropriate recipient is selected from the waiting list.
A family member, including brothers, sisters, parents, children (above 18 years of age), or any relative can be a living donor. A non-related person such as a close friend who wish to donate a kidney may also be considered. A series of tests will be conducted for potential donor candidates to check their health and matching tests to check compatibility with the recipients, in order to reduce chances of rejection.
The medical evaluation process: matching tests done before the procedure
The transplant team will conduct some tests to determine whether a donated kidney may be suitable for the recipient. The evaluation includes following matching tests:
Blood typing: Although, blood-type incompatible transplants (ABO incompatible kidney transplants) are also possible, it’s preferable to have a donor whose blood type matches or is compatible with the recipient. Incompatible blood type may require additional medical treatment before and after the kidney transplant to lower the risk of organ rejection.
Tissue typing: If the blood type is found compatible, the donor has to undergo a tissue typing test, also called as human leukocyte antigen (HLA) typing. HLA is a genetic marker present on cells and the test is used to compares these markers in recipient and donor. A good match reduces the likelihood of the body rejecting the organ.
Crossmatch: The final test for matching is known as cross-match which involves mixing the recipient’s blood with the donor’s blood in the lab. The test is used to determine whether the antibodies in recipient’s blood react against the antigens in the donor’s blood.
A negative cross match indicates compatibility and it means the recipient’s body is less likely to reject the donor kidney. Although, positive cross match kidney transplants are possible, it requires additional medical treatment before and after the kidney transplant to lower the risk of reaction of antibodies to the donor organ.
Other factors such as age, kidney size and infection exposure, are also considered by the transplant team while finding the most appropriate donor kidney.