6 out of 6

[George Jung]

What is the significance of a perfect match kidney? 
Why are these kidneys special enough to be transported from coast to coast when they arise? 
How important are matching antigens?

[tamara]

http://ihatedialysis.com/forum/index.php?topic=6510.msg96165#msg96165

I found this post of stauffenberg's to be interesting george in relation to this.

[Ang]

6  out  of  6   gives  your  new  kidney  the  best  out  come  of  durability,then  they  usually  work  backwards  if  6/6  is  not  an  option.

[George Jung]

tamara,  I did read that and found it interesting but I also read this....
 http://ihatedialysis.com/forum/index.php?topic=6510.msg96054#msg96054  "Jenna's donor was 1 of 6 match. The neph told us that the antibody crossmatch is much more of a concern, and that a 0 of 6 match from a living donor is a lot better than a 6 of 6 match from a deceased donor.

....then they usually work backwards if 6/6 is not an option.

Huh?

[angela515]

6/6 is the best transplant you can get, and I'm sorry, but that is true. The more perfect you match, the better your odds are of it lasting longer because the more perfect the match the more closer it is to actually being just like YOUR kidney in the first place. If that makes sense, sorry I'm not good at explaining these things like a doctor.

As for what "Ang" meant: 

"....then they usually work backwards if 6/6 is not an option. "

She meant if they can't find you a 6/6 of match, then it goes 5/6, 4/6 and so on to 0/6..

I have a 6/6 match this time, and it's more likely my kidney will last 20+ years, where as my last kidney (even though was a live donor AND from my mother) was only a 5/6 match and would have a less of a chance to last that long. However, as life happens, anything can happen and maybe someone with a 0/6 match will last longer than a 6/6/ match... however, it's going off statistics.

[stauffenberg]

Getting a kidney from a living donor, especially from one who is a blood relative, and thus shares with you many of the untested antigens, is more important than any number of matching sites from a cadaver kidney.  The main thing that induces the immune system of the recipient to panic and reject tissue is its perception of the subtle biological changes which indicate that it comes from a brain-dead donor rather than its perception of the antigen differences.  A younger live donor is also more valuable as a source of a new kidney, since the functional capacity of all kidneys declines over time, which is why some transplant centers refuse to accept donors over age 60.

[livecam]

The main thing that induces the immune system of the recipient to panic and reject tissue is its perception of the subtle biological changes which indicate that it comes from a brain-dead donor rather than its perception of the antigen differences. 

Where did the above come from?  I've never heard of such a thing.  My immune system knows that my kidney came from a brain dead donor?  Are you sure about that?

[angela515]

I disagree stauffenburg. I think every person's body is different to the situation and i'm sorry, but your body itself don't know where the donor kindey came from, and my perfect 6/6 match is working 100% better than my 5/6 I got from my mother.

[KT0930]

My 6/6 from a cadaver was working better two days after transplant (1.1 creatnine) than either of the 3/6 that I got from my parents. Lowest creatnine in 20 years with mom's was 1.4.

When you are on the list and have a high PRA, they try to get you as close to 6/6 as possible, because once you have a 6/6 match, you have a 90-95% chance of a negative cross-match, thus, a successful transplant. The 6/6 is also much closer to your own tissue, so less likely to be recognized by your immune system as foreign. I live in Atlanta, and had one 6/6 offered from Charleston, SC and one from Oklahoma. It is worth bringing one from that far away because a match that good is not likely to come up for someone who is highly sensitized. If that person was offered a 3/6 or less, the liklihood of it having a negative cross-match is greatly reduced, so they would be just as likely to keep that kidney in the local region and give it to someone who does not have a high PRA.

[Wattle]

A younger live donor is also more valuable as a source of a new kidney,

Was that the source for your own Transplant?

[kellyt]

I was told at my evaluation that a sibling donor is the best.  Is that because they are more likely to be a 6/6 match?   

[willieandwinnie]

Len's 5/6 came from a cadaver in Houston Texas and his creatnine has never been higher then 1.0 in 4 months. Transplant surgeon said that tissue match was better then some sibling transplants he has done. Just my 

[stauffenberg]

Gabriel Danovitch, medical director of the UCLA kidney transplant center and professor of medicine at UCLA has an interesting book, 'Handbook of Kidney Transplantation' (Philadelphia: Lippincott, 2001), which clears up some of these questions.  On p. 55 he writes: "The long-term success of living-unrelated donor kidney transplants is comparable to that achieved for transplants from parent donors and is greater than that achieved with equivalently HLA-matched cadaveric donors.  This may seem counterintuitive because living unrelated donors [in the statistics Danovitch discusses here] share no HLA haplotypes with their recipients." 

On p. 182 he takes up this theme again when he writes: " ... for those receiving cadaveric kidneys in 1995, the half-life [the time at which half of the kidneys had failed in the recipients] had increased to 11.6 years.  However, the half-life of two-haplotype matched living kidney recipients over this same time period was 22.8 years.  This suggests that we have a long way to go before the half-life for cadaveric renal transplants can be considered optimal."   

[BigSky]

The best long term outcomes for a tx are with those that share all 6 antigens. 

With each less antigen that matches the outcomes lessen.

However when one is at the top of the list they give them whatever kidney comes up.  Whether it be 1 or 4 or 6 match.

The only time they try to match against more antigens is if the person has a high PRA and or they have had a positive cross match on lower antigen kidney.

[KT0930]

On p. 182 he takes up this theme again when he writes: " ... for those receiving cadaveric kidneys in 1995, the half-life [the time at which half of the kidneys had failed in the recipients] had increased to 11.6 years.  However, the half-life of two-haplotype matched living kidney recipients over this same time period was 22.8 years.  This suggests that we have a long way to go before the half-life for cadaveric renal transplants can be considered optimal."   

He's using very small-number statistics here...incredibly unreliable and cannot be used to generalize.

[stauffenberg]

The phrase "two haplotype-matched kidney transplants" does not refer to the number of patients in the study, which was HUGE, but to the number of HLA matches represented in the transplanted organs, i.e., two out of six.  That study is cited in all the textbooks on transplants because of its recognized statistical reliability, given the very large sample of patients studied.  A further datum of interest which has been extrapolated from that same study, this time mentioned in the book by Professor R. Hricik, 'Kidney Transplantation' (London: Remedica, 2003) p. 5, is that, if you censor out of the statistics the large number of patients whose transplanted kidney fails because they die rather than the organ itself failing before they die, then kidneys from cadavers have a half-life of 19.5 years, while kidneys from live donors have a half-life of 35.9 years.  The superior survival time of living donor kidneys over cadaver source kidneys is undeniable.

[stauffenberg]

I should add that in one recent large-scale study comparing 37,000 kidney transplants from live donors and 71,000 kidney transplants from cadaver donors, the survival rate of the live donor transplants was found to be 50% better than that of the cadaver donor transplants when measured up to a 15-year cut-off point for the study.  The study is by D. W. Gjertson, "Survival Tables for Living Donor Renal Transplants," Clinical Transplantation (2003) pp. 337-386.

[BigSky]

The half life times are just guesses.

Half of live donor kidneys will have failed before that mark they think while the other half will last past that mark. 

Considering the OPTN stats at 10 years deceased donor kidneys are still functioning 66% to that of live donor kidneys at 73%.  Statistically that is not all that much IMO.   

[stauffenberg]

The average medical publication usually has from three to eight authors listed, and of those, if there are any statistical inferences involved in the article, there is invariably a professor of medical statistics among the authors, guaranteeing that the statistical significance of the inferences is impeccably accurate.  In the study which censored for loss of transplanted kidneys due to the death of the recipient, the difference found between the half-life of the live-donor source kidneys (35.9 years) and the cadaver-source kidneys (19.5 years) was 16.4 years.  If you consider that the average renal patient doesn't need a kidney transplant before age 40, a living donor kidney would probably be the last the patient would ever need in his life, but a cadaver source kidney would only last the patient until his mid-50s, which from my point of view is a HUGE difference.

[BigSky]

The average medical publication usually has from three to eight authors listed, and of those, if there are any statistical inferences involved in the article, there is invariably a professor of medical statistics among the authors, guaranteeing that the statistical significance of the inferences is impeccably accurate.  In the study which censored for loss of transplanted kidneys due to the death of the recipient, the difference found between the half-life of the live-donor source kidneys (35.9 years) and the cadaver-source kidneys (19.5 years) was 16.4 years.  If you consider that the average renal patient doesn't need a kidney transplant before age 40, a living donor kidney would probably be the last the patient would ever need in his life, but a cadaver source kidney would only last the patient until his mid-50s, which from my point of view is a HUGE difference.

 I do see what you are trying to say.

However,

Those numbers as to half life are made up are they not?  Its all mere speculation is it not? 

Or are there actually 18,500 patients from that study that have ACTUALLY had those kidneys over the half life mark of 35.9 years?

If  you take the 2005 OPTN/SRTR one can actually see the real world results at 10 years, not speculation.  To me 7% is not all that great at 10 years.

[paris]

Sometimes statistics just don't "jive" with everyday reality.  There are many members here that had a living donor, good match transplant that didn't last as long as statistics show.  Katie just got her third and the first two were from family members.   My  

[st789]

My is 1 out of 6 from a cadaver; therefore, transplant doctors do not want to lower my meds.  I am unlikely to receive another transplant in the future because of my Hep. B.

[KT0930]

In the study which censored for loss of transplanted kidneys due to the death of the recipient, the difference found between the half-life of the live-donor source kidneys (35.9 years) and the cadaver-source kidneys (19.5 years) was 16.4 years.

Ok, just curious...how many of us have heard of a kidney transplant (cadaver or living donor) that has lasted more than 30 years? I think I've heard of ONE ever, and that's the longest known surviving graft at around 36 years. Most I have heard of last up to about 20-25 years, and that's the max. Except for Amanda's father, who's going for year #27, but still not close to the "half-life" of 35.9

[jonn r]

no dont get me wrong....but....does it really matter how long that it works for...i mean come oneven one year of no dialysis is a thankful thing.....

[petey]

john r, you are basically right -- even one year of no dialysis is GREAT.  But, when a transplant is over and it's back to dialysis, it's awfully, awfully hard.  My Marvin's transplant lasted three years, three months.  Looking back now, those were the shortest three years, three months on record.

Even though we were a 1 out of 6 antigen match and immediate rejection was a real possibility, Marvin did not reject my kidney.  It caught the same disease he had in his original kidneys.  When it started working in his body on the operating table and the doctors realized (a month or so later) that it wasn't going to immediately reject, they said we could expect 12-15 years (as long as there was no rejection -- which we watched for night and day).  We felt cheated!  We were really counting on those 12-15 years.  Was it worth it?  You are dog-gone-skippy it was worth it!!!!  Would I do it again?  In a skinny minute!  What if I knew it would only last one year?  Yep, I'd still do it.  I'd do it again if I knew it would only last one month.   However, I think I'd be better prepared (emotionally) for going back on dialysis than we were.