Kidney Transplant

Kidney desensitization frequently asked questions

What does "sensitized" mean?

Approximately 30 percent of patients who are awaiting a kidney transplant are considered "sensitized." Through a test called Panel Reactive Antibody (PRA), we learn an estimate of the amount of antibody against foreign tissue that the patient has. The PRA is expressed as a percentage and shows the likelihood of having an antibody against a particular donor. A patient is considered sensitized if the PRA is greater than 20 percent. Having antibodies against foreign tissue makes it harder to find a compatible living or deceased donor kidney. Sensitized patients may wait three to four times longer for a compatible deceased donor kidney compared to a non-sensitized patient.

What are antibodies?

Antibodies are proteins that are produced by white blood cells to help the body fight infection. Antibodies circulate in the blood and bind to foreign proteins to stop them from causing damage to the body. The production of antibodies is the body's first line of defense in the immune response. These antibodies work hard to protect our bodies and keep us healthy. However, these same antibodies are bad for someone receiving a kidney transplant because the body can also form antibodies against foreign tissues, such as those found on a donated kidney. If a transplant is performed on someone who has these antibodies to their donor kidney, then the kidney will be rejected immediately.

What is desensitization?

Desensitization is a process that removes harmful antibodies from the blood stream. These antibodies, which fight foreign tissues like those found on a donated organ, can cause organ rejection. People who have this type of antibody typically develop them through a previous exposure to foreign tissue, such as a prior transplant, blood transfusion, or pregnancy. The antibody removal process is called plasmapheresis.

What is plasmapheresis?

Plasmapheresis treatments involve a plasma exchange that removes harmful antibodies from the blood. After each treatment, the drug immunoglobulin is given to help prevent the harmful antibodies from coming back. The number of treatments a patient needs is determined by the level of harmful antibodies present in his or her blood. These levels are checked frequently to determine if additional treatments are needed. Typically, two to four treatments are required prior to transplant. At the start of the plasmapheresis treatments, the patient receives anti-rejection medications to help prevent the reformation of the harmful antibodies. These anti-rejection medications are the same medications that the patient will continue to use after transplantation.

Why do I need a live kidney donor for the desensitization program?

The desensitization of the patient only lasts for a limited amount of time. The time to transplant has to be controlled very closely. This can only be done with a live donor. A patient on the waitlist for a donor organ will be transplanted at an undetermined time because it is unknown when a kidney will become available. Those patients do not have enough time prior to transplant, to go through the desensitization process.

What is a donor cross-match test?

In kidney donation, the most important test is the cross-match test. This test compares the blood cells of the donor and recipient. A laser identifies the presence and intensity of any antibodies the recipient might have against the donor. If the test is negative, antibodies that would work against the donated organ are not present, and the transplant can safely proceed. A positive result shows that antibodies that would work against the donor are present, meaning the kidney would be rejected immediately.

What if I have a positive cross-match with my donor?

At this stage, there are three options if the patient and donor have a positive cross-match. They include waiting for another donor who has a negative cross-match, participating in a donor exchange program, or undergoing the desensitization process.

What is the donor exchange program?

If a patient is incompatible with their potential donor through either ABO blood type or cross-match testing, they can be evaluated for a donor exchange. This approach allows patients with willing but incompatible donors to exchange kidneys. In a kidney exchange, both patients get transplants and both donors give kidneys, but each kidney goes to a different patient than for whom it was originally intended.

What are the costs of desensitization?

Patients who go through the desensitization program can expect an additional $20,000 to $30,000 above the cost of a kidney transplant that does not require desensitization.

Will my insurance cover my transplant? How much?

UW Health has contracts with many insurance providers, Medicare and Wisconsin Medicaid. Patients should contact their insurance company to determine their transplant surgery coverage. Patients who have questions after contacting their insurance company may call (608) 263-1503 to obtain assistance from a transplant financial counselor.