Testing Involved in the Living Donor Evaluation Process
The following process is used to determine if someone can be a donor. This is a general description of the testing process, and may vary from center to center:
A medical history review and physical examination. An extensive review of all systems, including previous illnesses and surgeries and past family medical history. Any abnormalities found are investigated further before invasive tests are performed.
A financial consultation will be used to determine financial and insurance coverage for the testing process and the donation itself. Generally, if the donation is to a family member or friend, the recipient's insurance will pay for testing and surgery expenses. However, the donor might be responsible for travel expenses (if the donor and recipient live in different towns/states) and follow-up care, in addition to lost wages. Since donors are never financially compensated, be sure to ask the financial counselor and/or social worker at the transplant center for assistance with these issues.
Immunological Tests: A blood sample is taken for the following tests:
ABO test to determine the donor's blood type: O, A, B, or AB Please note that there are some programs that may help donor/recipient pairs with blood types that are incompatible: paired exchange and plasmapheresis.
Tissue typing is used to identify the donor's particular HLA antigens and determine if the donor and recipient are compatible. Each person's tissues, except for identical twins, are different from everyone else's. It is believed that the better the tissue match, the more successful the transplant will be over a longer period of time
An antigen is a genetic marker. Genetic markers are unique to your body. You may hear these called HLA, or human leukocyte antigens. The process of identifying these antigens is called tissue typing. The leukocytes, or white cells, in your blood carry these antigens and are used to identify them. More than 7,000 to 8,000 combinations of known antigens are possible.
Family analysis: If an entire family is being tested, blood samples will be taken of all potential donors to determine compatibility. This takes approximately one week before the results are known.
Assess the amount of protein excreted in a 24-hour period. An increased secretion of protein would need to be evaluated before resuming the evaluation; the creatinine clearance is to determine adequate kidney function and to ensure that collection is an adequate one.
Female donor candidates may undergo a gynecological exam and mammography.
An intravenous pyelography test may be used. This test involves an injection of dye into a vein in your arm. The dye circulates through your body, into your kidneys, and then into your urinary tract. X-rays are taken to identify the structure of the kidney, veins, arteries, the ureter, and other anatomy.
A Helical CT Scan is done in some transplant centers. The helical CT scan is used to evaluate the internal structure of the kidney and look for the presence of cysts, tumors, etc.
Some transplant centers will perform a renal arteriogram if there is a question of an abnormal finding on the Helical CT Scan. The renal arteriogram is an x-ray which looks at the vasculature of each kidney: the number of blood vessels to and from each kidney, or any evidence of vascular disease that might rule out donation. This test requires an observation period post-exam of 6-8 hours and in some instances may require hospitalization.
NKF Cares is a free, confidential hotline with trained professionals ready to answer your questions or concerns. Our peer-mentoring program, NKF PEERS, connects anyone affected by kidney disease with an informed and supportive mentor who has already been through the process.