h a l f b a k e r yTrying to contain nuts.
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Some folks donate their organs when they die. Other people have these implanted then walk around and use them. But the native immune system may take umbrage at the new organ and try to destroy it. This necessitates immune suppressive drugs, to hamper the native immune system to the point where it
accepts the organ. If the immune system rejects the organ anyway, the recipient might go back on dialysis, need another transplant, or die.
Organ donors usually do not have their marrow harvested. This seems wasteful, since people with bone marrow diseases and leukemia sometimes need bone marrow transplants, and an organ donor could donate all their marrow, which is freezable and so could be used at a later date should it prove to be a match for someone who needs it.
The other thing this banked marrow might be good for is organ rejection. The donor and the recipient of the organ (say a heart) would have to be HLA matched. But the immune system of the original donor would be friendly towards the organ and leave it alone. Someone rejecting their organ might take on the donors immune system so the rejection would stop. The rest of the recipient's body is another matter, but the rest of the body can step up and take one for the team in exchange for leaving the transplanted organ alone. This would trade the risks of immunosuppression and organ failure for the risks of immunosuppression and graft-versus-host disease, which might or might not be a good trade.
One might make a case to do such an allogeneic bone marrow transplant in a planned fashion. This would be especially useful for those babies who get multiorgan transplant - intestine, pancreas, liver etc etc. For these babies, rejection is common and lethal. After they heal following transplant, a planned marrow transplant from the organ donor would prevent rejection.
Last halfbaked scheme: before embarking on an allogeneic bone marrow transplant in hopes of saving a transplanted organ, the recipient could bank his or her own marrow/stem cells. If the new immune system proved too rowdy as regards graft-versus-host disease, they could ablate their new transplanted immune system and get their old immune system back. It would probably stumble in, half dazed, and take some time before it got back to its old tricks trying to destroy the transplanted organ.
Human blood groups
http://en.wikipedia...iki/Abo_blood_group
Blood ! Blood ! [8th of 7, Aug 08 2008]
Major histocompatibility complex
http://en.wikipedia...mpatibility_complex
The basis of tissue typing [8th of 7, Aug 08 2008]
Sooner donors
http://sports.espn....ws/story?id=3522559
[jaksplat, Aug 09 2008]
Baked!
http://www.chicagot...308,0,4428804.story
These folks get the bone marrow transplant up front, as far as I can tell. [bungston, Mar 08 2012]
[link]
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Even if transplanting the marrow transfers the immune system, which sound DEEPLY suspicious, wouldn't it then attack all the rest of the body? |
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I'm not boning because I have only the vaguest idea what you are talking about, I'll wait for the specialist wolves weigh in. |
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BTW how long does bone marrow store? I think it would worth it for the stem cells, but while you are at it, get the ones out of the nasal passages. |
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The problem would be the sheel quantity of marrow you'd have to store. Tissue typing is waaaay more complex than blood grouping. |
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Because of the statistical distribution of your blood types - notwithstanding the Rhesus factors - half a dozen blood types cover the bulk of your population of "homo sapiens". <link> |
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However, there are many more histocompatibility facotrs in tissue than in blood. |
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[+] for a well meaning, if impractical, idea. |
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Bone marrow is one of the most imunosensitive tissues. Even close typings from a sibling are frequently rejected. A random donor tissue has a snowball's chance in hell. |
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//Major histocompatibility complex// |
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sp: Major histocompatibility complicated! |
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I'm suspicious of [bungston] on this one. I think he's seen the latest research... |
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The use of immunomodulating cells similar to embryonic stem cells has been demonstrated to reduce or eliminate the requirement for immunosuppressants with murine allografts [that is, transplants from rats to other rats] (Turka, et al, Nature Medicine, 2002); the use of these "Transplant Acceptance Inducing Cells" in humans has recently (this week!) been described in level 1 clinical trials in Germany (F Fandrich, J Hutchison, et al, Transplant International, 2008). |
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It's not a "random donor" situation. The immune modulating cells of the graft recipient are "processed" (the procedure is not described in the abstract and I don't have the $31.50 for the rest of the article) with cells from the organ donor. These cells are then injected into the bloodstream of the organ recipient. The size of the clinical trial was small (n=12), but results seem to indicate that using the "TAIC" therapy *prior* to the transplant worked better than those who received it post-op. |
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So it would seem that you'd only need to bank the marrow for as long as you have to wait for someone to need the organs. That is, not long at all. |
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bone marrow and stem cells are
different things. pluripotent cells and,
in situ, the tissues they form seem to
represent a special case. Looks like
stem cells are able to team up with
nearby cells to form immune safe
communities. I don't think a simple
bone marrow transplant would do this
nor would this produce a new immune
system as that would involve a high risk
of broader cell rejection. Some middle
path of immune learning/adaption with
exposure is a more likely explanation.
Anyone out there know any more about
this? |
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possibly using cord or fetal cells? I know
that the communal aspect of tissues
produced with cord cells it well researched. |
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I like this, but what is 'halfbaked' about it? |
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//I like this, but what is 'halfbaked' about it?// |
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//The rest of the recipient's body is another matter, but the rest of the body can step up and take one for the team in exchange for leaving the transplanted organ alone.// |
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So the organ recipient inevitable dies of massive organ failure, *except* for the transplanted organs, which remain pink and healthy. |
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/but what is halfbaked about it?/ |
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High praise! Thank you Moonguy. |
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As regards the ever crusty (but note:
not a flaky crust!) ldischler, it is true
that HLA mismatched bone marrow
transplants are bad for you. Not all
organ donors are HLA matched. This
scheme would only work for those that
were. Given the number of transplants
going on, a little bit of logistics work
would allow more HLA-matching than
currently goes on - availability of a
matched kidney could allow a waiting
recipient to cut in front of the line and
take it. |
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Even if the organ recipients dont get the
marrow, it should be banked anyway.
Someone could use it, someday. |
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I can't live without you.... so will you
marrow me? |
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Right now it's too dark. But the sun will
come out to marrow. |
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"Marrow in haste, replant at leisure ....." |
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// I think he's seen the latest research... // |
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Yes - lucky for us he can't read ..... |
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I am pleased to see that this proposal has been baked; see link. I understand that "bungston" cannot be given authorship credit, but I think it only just that the procedure popularly be known as the "Bungston Maneuver". |
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