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Face transplant recipient’s donor face now failing

latimes.com

31–40 of 112 posts

Re: Face transplant recipient’s donor face now failing

#31
post #23
post #20

Earlier quoted context omitted.

> Any time we do any transplant immunosupressants are given to the recipient for the rest of their life, but this only slows the inevitable. Is this true that it is inevitable? My understanding, from my girlfriend attending medical school (only M1), is that for many types of transplants, when immunosupressants are taken properly, it is unlikely that the organ will ever be rejected. For example, only 10-20% of patient…

“Only 20%” and “unlikely to ever be rejected” are worlds apart. Modern immunosuppressive therapy for, for instance kidneys, has dropped the five year acute rejection rate from 50% to 20%. About 8-10% in the first year. You can get a 5% 10-year non-rejection rate only in the most hand-picked groups (adheres to meds, no underlying systemic disease, and no chronic nephropathy). That sub-population exists, but it’s prett…

People without underlying disease generally dont need or get replacement organs. These are all complex cases. Only in the most rare of circumstances does an otherwise totally healthy person need a new kidney.

Re: Face transplant recipient’s donor face now failing

#32

This is to be expected. Any time we do any transplant immunosupressants are given to the recipient for the rest of their life, but this only slows the inevitable. Heart transplants recipients all get accelerated atherosclerosis. Lung transplant recipients all get long term fibrosis. We buy time with these procedures and do everything we can to keep them going, but if you have a transplant, you're in a really bad spot…

How much of this is mitigated by donor/recipient compatibility (haplotypes? is that the right word?)? Is there no such thing as a purely compatible donor?

Re: Face transplant recipient’s donor face now failing

#33
post #12

Earlier quoted context omitted.

I just finished up an introductory biology lecture series, and this suddenly makes less sense to me than it did before. What is it about the foreign cells that is identified as foreign by the host cells? The cells ought to be remarkably similar. They're human, with the same function/pluripotency using the same protein interactions. So why attack it?

Adding to some of the other comments: Leukocytes (immune cells) such as B and T cells will undergo "education" when they are developing. For example, B cells, before being released, will go through something called central tolerance in the bone marrow. If the B cell receptors bind a "self" antigen (markers that are associated with our own cells) while developing, it will go through negative selection and be destroyed…

Thanks for this. I'm perpetually amazed at how mind-bogglingly complex the human body is.

> while developing, it will go through negative selection and be destroyed

Can you share more about how this process works? Even just a link would do. Thank you!

Re: Face transplant recipient’s donor face now failing

#34
post #25

Earlier quoted context omitted.

Probably has some sort of MAC address identifier that can detect whether something if different than the host DNA, but I have no idea nor experience in biology.

I’d say it’s probably more like some kind of checksum against the DNA. If the body detects something has been changed from what was there before it dispatches the white blood cells to kill it off. Immunosuppressants are a way to bypass the checksum, but only for some limited time. Maybe we need a way to change the checksum values altogether, but then the whole body could be rendered rejected and cease to function (de…

This is actually an issue in graft-vs-host rejection for bone marrow transplants.

Re: Face transplant recipient’s donor face now failing

#35
post #25

Earlier quoted context omitted.

Probably has some sort of MAC address identifier that can detect whether something if different than the host DNA, but I have no idea nor experience in biology.

I’d say it’s probably more like some kind of checksum against the DNA. If the body detects something has been changed from what was there before it dispatches the white blood cells to kill it off. Immunosuppressants are a way to bypass the checksum, but only for some limited time. Maybe we need a way to change the checksum values altogether, but then the whole body could be rendered rejected and cease to function (de…

I love tech analogies to biological functions.

It amazes me how much 'tech' is always running on a cellular/molecular level.

Thank you!

Re: Face transplant recipient’s donor face now failing

#36
post #23
post #20

Earlier quoted context omitted.

> Any time we do any transplant immunosupressants are given to the recipient for the rest of their life, but this only slows the inevitable. Is this true that it is inevitable? My understanding, from my girlfriend attending medical school (only M1), is that for many types of transplants, when immunosupressants are taken properly, it is unlikely that the organ will ever be rejected. For example, only 10-20% of patient…

“Only 20%” and “unlikely to ever be rejected” are worlds apart. Modern immunosuppressive therapy for, for instance kidneys, has dropped the five year acute rejection rate from 50% to 20%. About 8-10% in the first year. You can get a 5% 10-year non-rejection rate only in the most hand-picked groups (adheres to meds, no underlying systemic disease, and no chronic nephropathy). That sub-population exists, but it’s prett…

> “Only 20%” and “unlikely to ever be rejected” are worlds apart.

The parent comment I responded to stated it was "inevitable." "Inevitable" and "only 20%" are many more worlds apart than "unlikely to ever be rejected" and "only 20%".

"Unlikely" is a bit subjective, but it is well below a coin flip.

I cited a source for the statistics. If you disagree, can you please cite your source?

Re: Face transplant recipient’s donor face now failing

#37
post #32

This is to be expected. Any time we do any transplant immunosupressants are given to the recipient for the rest of their life, but this only slows the inevitable. Heart transplants recipients all get accelerated atherosclerosis. Lung transplant recipients all get long term fibrosis. We buy time with these procedures and do everything we can to keep them going, but if you have a transplant, you're in a really bad spot…

How much of this is mitigated by donor/recipient compatibility (haplotypes? is that the right word?)? Is there no such thing as a purely compatible donor?

A 100% compatible donor is a identical twin or clone. Besides the MHC haplotypes which govern large parts of the immune response to ‘self’ there is the actual makeup of the rest of the genetic material which may be presented as antigens and then recognised as foreign

Re: Face transplant recipient’s donor face now failing

#39

> “We all know we are in uncharted waters,” Tarleton said. “I would rather not have to go through a catastrophic failure.” If anyone hasn't been through some tragic medical shit in their life, pay attention to that. You'll understand it later.

This is what gets me. Take care of yourself, because you don't know what kind of Sword of Damocles is hanging over your head.

A lot of us think we are invulnerable when we are young. I had a college friend who died of brain cancer a few years after graduating. I myself had a kidney failure a few years ago and now on dialysis. In the snap of a finger your life can change.

Re: Face transplant recipient’s donor face now failing

#40
post #12

Earlier quoted context omitted.

I just finished up an introductory biology lecture series, and this suddenly makes less sense to me than it did before. What is it about the foreign cells that is identified as foreign by the host cells? The cells ought to be remarkably similar. They're human, with the same function/pluripotency using the same protein interactions. So why attack it?

Because it's part of the arms race with pathogens that has been going on for a billion years since multi-cellular life first appeared. Pathogens do lots of very clever things to hide from the immune system, so the immune system is tuned to detect very subtle changes. The body largely operates on zero-trust network models, except for a few locations where the benefit of a too-active immune system has serious consequen…

> except for a few locations where the benefit of a too-active immune system has serious consequences

For anyone else curious about this, https://en.wikipedia.org/wiki/Immune_privilege

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