Earlier this week I received an email from Charlotte, a renal nurse in the UK, telling me about an excellent podcast on RTÉ Radio 1 in Dublin, called Wanted: Kidney. The podcast is based around Regina Hennelly, a 29-year-old Dublin journalist who has been on PD for two years. It covers a lot of ground, beginning with Regina’s story: her kidney failure at 25, her experiences on PD; and its primary theme, how it feels waiting in suspended animation for a transplant. It also talks with other BigD club members and provides an excellent overview of the state of kidney transplants in Ireland.
It is well worth the 36-minute investment.
[Regina also writes a blog “about dialysis and other curiosities” called This Limbo. Her profile says it all: Fun-loving non-smoker, social drinker (29), looking for necessary new lease of life. WLTM healthy kidney who shares her interest in travel without Peritoneal Dialysis machine and her fetish for midriffs without tubes attached. GSOH in bad times essential. Only kidneys interested in long-term relationship need apply. (Not being experienced in matching service lingo, I discovered that WLTM means Would Like To Meet and GSOH means Good Sense Of Humour.) It’s a good read, especially for fellow PDers.]
Talking of transplant waiting, the time obviously varies depending on where the donor kidney is coming from. There are two sources: living donors (typically family or very good friends) and deceased donors. I have been lucky enough to have had both. My wife Julie donated one of her kidneys to me in 1995. Unfortunately because of rejection that kidney only lasted three months. As a result, I had antibodies that stopped further transplants for nearly ten years (see crossmatch below). Finally, I received a deceased donor kidney in 2005, which lasted until 2008.
There is quite a workup time for living donors, which can be 12-18 months. A lot has to happen and I’ll cover that in a later post.
Like in Regina’s podcast, there has been a rash of transplants here (in Victoria) over the last year, from both living and deceased donors. But the list continues to grow, and the typical waiting time, if there is such a thing, for deceased donors is 2-4 years plus.
I say if there is a typical waiting time because it is not just the amount of time you have been on the list, but more importantly, how good a match the donor kidney is. There lies the rub. Donor and recipient matching involves testing in three areas: blood type matching, tissue type matching and crossmatching, and you need to pass all three before your position on the list gets you a kidney.
Blood type matching is straightforward: a recipient with blood type O can receive a kidney only from a donor with blood type O; a recipient with blood type A may receive a kidney from a recipient with blood type O or A; a recipient with blood type B can receive a kidney from a donor with blood type O or B; and a recipient with blood type AB can receive a kidney from a person of any blood type.
If the blood types match, the next tests are for tissue type. For kidney transplants, there are at least six specific blood and tissue types, called antigens, which define how well you may be compatible with a donor. The best compatibility is a six-antigen match. This match, which occurs 25 percent of the time between brothers and sisters having the same mother and father, also occurs from time-to-time in a random fashion in the general population. As the number of antigen matches fall, so the outlook for a long-term transplant falls. This outlook can be improved with a greater (and sometimes heroic) use of anti-rejection drugs, but these have their associated, cumulative and usually unpleasant side effects.
If you pass tissue type matching, the final crossmatch test mixes donor and recipient cells and serum to determine whether your body will attempt to reject the kidney. Throughout your life, your body makes substances called antibodies that act to destroy foreign materials. You may make antibodies each time you have an infection, are pregnant, have a blood transfusion or undergo a kidney transplant. If you have antibodies to the donor kidney, your body will destroy the kidney. So the final crossmatch test is to ensure that you don’t have antibodies to the donor. The test outcome is either positive or negative: a positive crossmatch means that you have responded to the donor and that the transplant should not be carried out; a negative crossmatch means that you have not responded to the donor and therefore transplantation should be safe.
(The above info is a summary from the UCSF Health website.)
So, in summary, the deceased donation transplant process works like this:
- You provide regular (usually monthly) blood samples to your transplant hospital/blood service. Then, when
- A kidney becomes available to your transplant hospital
- If your name is at or near the top of the waiting list (based on the time you have been waiting)
- The transplanting hospital/blood service will check that your blood type matches the donor’s
- If OK, they will test your tissue type compatibility
- If acceptable, they will crossmatch your cells with the donor’s
- If there is a negative crossmatch,
- They will offer you the kidney.
Then the fun begins, and it’s usually worth the wait.