An important exception to ABO incompatibility is the A2 blood group: because the A2 antigen is expressed at lower levels on kidney endothelium than other antigens, A2 kidneys can be successfully transplanted into either B or O recipients without desensitization, provided the cross-match is negative and the anti-A2 titers are relatively low.
Monday, January 12, 2009
ABO Incompatibility Renal Transplant
Although the traditional dogma of kidney transplant would state that ABO incompatibility is an absolute contraindication for a kidney transplant, this is changing: there are some overall favorable reports of graft longevity in Japan, where cadaveric kidneys are in severe short supply. In order to prevent acute rejection, a desensitization protocol involving therapeutic plasma exchange, IVIG, or Rituxan (all of which would be designed to minimize circulating anti-A or anti-B antibodies in the recipient) may be employed.
Labels:
immunology,
Nathan Hellman,
transplant nephrology
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5 comments:
ABO incompatible transplants are currently being done with a very high, about 98%, success rate at Cedars-Sinai in Los Angeles, Ca. This is not just something being done in Japan. Cedars-Sinai is also using IVIG for high anti-body patients to make them compatible to their living or cadaveric donors with a 95-98% success rate.
We are doing them here as well at Brigham & Women's Hospital--sorry, didn't mean to suggest that this technology was only in Japan, though it does appear that a lot of the literature derives from there. I will say though that it seems that the trend here is to suggest a kidney-exchange program (where a mismatched donor-recipient pair finds a complemenatary mismatched pair) rather than proceeding directly to the ABO incompatibility protocol given the additional complications possible with higher immunosuppression.
At the University Medical Centre Utrecht, the Netherlands we only perform an ABO incompatible transplant after two rounds of the kidney exchange program failed to result in a match with another pair. Considering the extra costs involved in ABO incompatibility (we use IVIG, plasma exchange and Rituximab) this may be an economical sound approach.
Excellent blog by the way.
I don't know who pays for dialysis in the Netherlands. In the United States Medicare has agreed to pay for the ABO incompatible and the highly sensitized protocols at Cedars because of the huge savings when a patient no longer needs dialysis. In the last five years Cedars-Sinai has done 400 of these incompatible transplants with people's own donors. The paired exchange programs internationally of done fewer than 200 in the same time period. All the people with incompatible donors who did not find a match in these paired exchange programs are either still on dialysis or dead. It is unethical not to learn the successful new protocols and match people to their own donors and it is uneconomical. No one talks about the conflicts of interest that nephrologists and transplant centers have by owning and profiting from dialysis clinics. In the United States only 15% of people in kidney failure are actually on waiting lists at transplant centers. Most people believe they have to be referred by their doctor by Medicare makes it clear people can refer themselves if they feel their doctor is dragging his feet. Once they get to a transplant center, on average in the US. only 12% are actually transplanted. The kidney specialists have overwhelming personal financial motives not to learn the new protocols which, when dialysis is no longer needed, is a savings to Medicare of at least %72,000 a year per patient. That %72,000 no longer goes to the nephrologist and the dialysis corporation he/she works for. The argument that desensitization is too expensive has been unsound from the beginning. What is meant is that it is a financial loss for the people who profit from dialysis. They lose customers when people regain their health and return to life and can work and be productive members of society.
There is even a better protocol than those that previous bloggers and commentators have put forward, namely Glycosorb AB0! The swedish company Glycorex manufactures it and is approved in EU,Canada, Australia, but not in the US and Japan yet. I expect FDAs approval this year.
www.glycorex.se
Those that say it´s expensive with ABOi-transpl. must realise that dilaysis is more expensive and not good for the patient in the long run
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