Excellent outcomes can occur when a patient receives a kidney from a healthy living donor, regardless of whether or not the donor is a relative. In the past, relatives, such as siblings, parents or children, made up the vast majority of living donors, due to the importance of tissue matching. Improved medications to prevent kidney rejection have made tissue matching less important. Today, unrelated living donors, such as spouses and friends, represent a large segment of living donors.
A potential donor’s blood type will be determined first because kidney transplants can only occur between people with compatible blood types. Four blood types occur in humans: O, A, B or AB. The Rh factor (negative or positive) is important for blood transfusions but does not need to match between the kidney donor and the transplant recipient.
The following chart shows blood-type matching that permits organ donation:
|If the Recipient's Blood Type is:
||The Donor's Blood Type must be:
||A, O, or B
||O or B
||O, A, B, or AB
Further Donor Evaluation
After the initial blood test shows a compatible blood type with the recipient, the potential donor will undergo more extensive pre-transplant testing. If risk factors for future kidney disease are found at any point in the pre-transplant evaluation, a donor will be declined. He or she may be directed to seek further medical care. Sadly, some highly motivated potential donors may not be acceptable candidates to donate a kidney.
The donor’s initial pre-transplant evaluation includes:
- A complete medical history and physical examination by a kidney specialist (nephrologist)
- Chest X-ray and EKG
- Blood tests to assess blood-cell counts, liver function and the presence of diabetes or infectious diseases, such as HIV and hepatitis.
- Assessment of kidney function, which will include two 24-hour urine collections
- A complete gynecological examination for all female donors and a mammogram for women 32 years and older
- Evaluation of the gastrointestinal system
- A preliminary crossmatch. This tests the interaction between the donor’s and the recipient’s blood cells. The blood serum of the recipient may contain antibodies that can react with the donor’s cells. If these antibodies are present (a positive crossmatch), the transplant cannot be performed. This test will be repeated just prior to the transplant surgery.
- Tissue typing of the donor cells. This is another blood test, which evaluates the match between six codes on the donor and recipient cells. While still required as part of the transplant process, lack of tissue matching is rarely a barrier to donation.
The transplant nurse coordinator arranges the donor evaluation through testing conducted at Swedish or, if more convenient, at an appropriate facility closer to the donor’s home.