by George Taniwaki

Patients with end-stage renal disease (ESRD) often wait many years for a transplant. There are currently over 85,000 people in the U.S. waiting for a kidney transplant and the number grows each year. The average wait time is over three years. The mortality rate for those with ESRD on dialysis is over 15% per year, meaning that almost half of the patients die and never get a transplant.

Eliminating the waiting list for kidney transplants is a complex problem. But I see four separate solutions. They are reduce the incidence rate of ESRD, increase the supply of deceased donor organs, increase the supply of live donor organs, and apply new technologies to enhance or replace human organs. These solutions are not mutually exclusive and should each be investigated and instituted by the appropriate organizations. In fact, I don’t believe any one of these solutions will eliminate the list on its own, and so possibly all of them will need to be pursued.

I will illustrate the various pieces of this problem with the four flow charts shown below and then discuss each of the four solution areas in future blog posts. The text in orange boxes represent actions that can be taken. The text in green boxes indicate the intended results of those actions.

Access to healthcare

For blog posts related to patient access to preventative care, patient education on treatment modalities, or dialysis treatment, see entries tagged with Access To Healthcare or Dialysis.

Note that in the right side of Figure 1, educating patients about the advantages of transplant therapy will increase the demand for transplants, which will make the waiting list longer if other steps are not taken to reduce the incidence of ESRD or increase the supply of organs.

KidneyFlowESRD

Figure 1. Actions that may reduce the incidence of ESRD (left) and increase demand for transplant therapy (right)

Deceased donor transplants

For blog posts related to deceased donor transplants, including patient evaluation and experience, see entries tagged with Deceased Donor.

KidneyFlowDeceasedTX

Figure 2. Actions that may increase supply of deceased donor kidneys

Live donor transplants

For blog posts related to live donor transplants, see entries tagged with Live Donor or Kidney Exchange. (For more on the live donor evaluation process, see entries tagged with Donor Story.)

KidneyFlowLiveTx

Figure 3. Actions that may increase supply of live donor kidneys

New technologies

For blog posts related to alternatives to current transplant therapy, see entries tagged with Artificial Organs, Stem Cells, and New Therapies.

KidneyFlowNewTech

Figure 4. New technologies that may someday replace standard transplant therapy

Disclosure note: I am a community member of the Organ Donation Legislative Workgroup in Washington state. I am also a volunteer for several organizations that provide healthcare services to patients with ESRD. However, the opinions in this blog post are my own and do not represent those of any group.

All images by George Taniwaki

[Update1: I modified Figure 3]

[Update2: I added links to tagged blog posts]

Currently, the best test to check for organ rejection is a biopsy. This is an invasive procedure that is expensive and can lead to complications. In a biopsy, a probe is inserted to extract a sample of the transplanted organ. The cells in the sample are then stained and viewed under a microscope to see if they are being attacked by the patient’s immune system.

A new noninvasive test has been developed by researchers led by Hannah Valentine, a cardiologist at Stanford University, and published in Proc. Nat. Aca. Sci. Mar 2011. Their test, which is designed for heart transplant patients, relies on the fact that once the immune system begins to attack the transplanted organ, some of the cells in that organ die, are decomposed by the immune system, and carried away in the blood stream. Since the transplanted organ has different DNA than the host, the level of foreign DNA in the patient’s blood will rise. This DNA can be detected and measured using a simple blood test.

Stanford University is applying for a patent for this process and expects to license it. A good description on the development of this test appears in Tech. Rev. Mar 2011. This new test may be used in conjunction with an existing simple blood-based genetic test sold under the trade name AlloMap, that can predict which patients are most likely to have an active immune system that will lead to organ rejection. The combination of the two tests could provide a better guide for clinicians to adjust the types and dosages of immunosuppressant medications to provide transplant patients with the lowest amount needed to avoid rejection. It will also allow faster diagnosis of rejection to so that  treatment can be adjusted as needed.