• Quick note - the problem with Youtube videos not embedding on the forum appears to have been fixed, thanks to ZiprHead. If you do still see problems let me know.

Transplant girl's blood type changes!

The Atheist

The Grammar Tyrant
The Atheist
Joined
Jul 3, 2006
Messages
36,364
Any Aussies able to confirm this story, which seems a little odd. I can't find it on ABC and it's just arrived on the Herald this afternoon.

May be an amazing discovery.
 
Theoretically it's sound, I guess. Yet I'm curious to know how stem cells managed to take over all of her bone marrow functions - surely she'd still have her own marrow in some areas which would produce blood cells of her own marker type. That said, the fact she had leukaemia and a suppressed immune system to begin with, lacking memory cells which would attack the minor HL marker differences present on the donated cells...it's not beyond imagination to see how this could happen.

No word of it has come past my desk, though. I'll check some of the science media sites.

Athon
 
After a search, I found the paper. Here's the abstract:

[FONT=arial, helvetica] Complete hematopoietic chimerism and tolerance of a liver allograft from a deceased male donor developed in a 9-year-old girl, with no evidence of graft-versus-host disease 17 months after transplantation. The tolerance was preceded by a period of severe hemolysis, reflecting partial chimerism that was refractory to standard therapies. The hemolysis resolved after the gradual withdrawal of all immunosuppressive therapy.
Click to expand...

Quite interesting. I could probably chase up the full text.

Athon
[/FONT]
 
rjh01 said:
This was on the ABC (Australian) TV news.

Edit - here is a link to the news Aust doctors hail teen's transplant 'miracle'

Edit2 - From the New England Journal of Medicine [FONT=Arial, Helvetica, sans-serif]Chimerism and Tolerance in a Recipient of a Deceased-Donor Liver Transplant[/FONT]
Click to expand...

But she became very ill nine months later, suffering pneumolysis - a breakdown of the red blood cells.
Click to expand...

From first link above. This is an incorrect usage. The correct term for breakdown of RBCs would be hemolysis. The term used, pneumolysis, describes the separation of the lung from the pleura. It was usually done surgically to facilitate therapeutic pneumothorax or collapse of the lung to treat tuberculosis.
 
I read through the report. While unusual, this occurrence is not unique. This sort of chimerism happens with bone marrow transplant, but has been seen with liver transplant as well, as has the ability to withdraw immunosuppressive drugs.

Linda
 
fls said:
I read through the report. While unusual, this occurrence is not unique. This sort of chimerism happens with bone marrow transplant, but has been seen with liver transplant as well, as has the ability to withdraw immunosuppressive drugs.

Linda
Click to expand...


The article about this states the following:

"Transplant patients and immune disease sufferers have received new hope from a 15-year-old Sydney girl hailed as a "one-in-six-billion miracle" when her body took on her liver donor's immune system.

Doctors at Sydney's Westmead Children's Hospital say Demi-Lee Brennan has achieved "the holy grail of transplants" in the only known case of its kind."



If this is incorrect and this was not a first, can you please provide a source? Thanks.
 
Last edited:
Yep, that's how I read it as well - the first known occurrence, so if not, let's see the details.
 
Here is a related news story US scientists develop transplant without anti-rejection drugs

They say they have successfully transplanted kidneys into five patients, four of whom were able to stop taking the anti-rejection drugs.
<snip>
The scientists say the key to the breakthrough is that doctors transplanted some of the donor's bone marrow as well as the kidney.
They first killed off mature immune cells in the recipient.
They then transplanted the kidney and the bone marrow.
When the recipient's immune system recovered, it treated the foreign organ as part of itself.
Click to expand...

It seams like the scientists have independently developed a way of doing the same thing as what happened naturally.

The only thing I do not understand is why the bone marrow does not reject the host.
 
It really should be no surprise (I hope) that the lay press failed to capture what it is about this case that is unique or useful. Please bear with me as I make an attempt.

It is common for recipients to develop some degree of chimerism post liver transplant. The liver is a site of hematopoiesis (production of blood) although to a much smaller degree than the bone marrow, so it contains the same kinds of cells that are involved in bone marrow transplants. Usually the chimerism in liver transplant is transient and does not persist. Even if it does persist, the immunosuppressive drugs also have the effect of suppressing the donor immune reactions, so they are not given the opportunity fully replace the recipient's immune system.

What was unusual in this case, is that the degree of engraftment (establishment of the hematopoietic cells) was much greater - more like what is seen with bone marrow transplant. It is hypothesized that the reason for this was due to the young age of the donor (12) and the recipient (9). The dose of the hematopoietic cells was larger than you would receive from an older liver, and other factors related to both the acute illness that led to transplant and an acute CMV infection post-transplant meant that the recipients own population of immune cells was dramatically reduced (a natural version of the destruction of the immune system that is done purposely prior to a bone marrow transplant).

A war developed between her few remaining immune cells and the blood cells of the recipient. Because she had such an unusually large degree of engraftment, this was a war that the donor cells could actually win. For that reason, her immunosuppressive therapy was discontinued and the donor cells essentially eliminated her remaining immune system.

This case is unique (as far as I know) in the particular combination of events and that processes that previously were deliberately induced in others happened on their own. It is not unique because doctors have never seen these processes before or cannot come up with a plausible explanation.

This issue of the NEJM contained 3 reports on a variety of patients that were able to come off of immunosuppressive drugs due to this sort of chimerism, and an editorial from Thomas Starzl (one of the main players in the field of transplantation) discussing the implications. It is important because it helps solidify hypotheses/theories on how and why some people are able to survive without immunosuppressive therapy. And it also lends credence to the promotion of alternate methods that have been used or are undergoing experimental development, of dealing with rejection.

Linda
 
Last edited:
Of course, what we really want to know is, did she acquire the memory or personality of the donor...
:duck:




ETA: Linda, thanks for the explanation, that really is fascinating.
 
Last edited:
That's fascinating, Linda.

(has anyone else found that doing google research on blood types is a bit tricky, with all the "How to diet for your blood type" and "what your blood type says about your personality" pages?)
 
fls said:
This case is unique (as far as I know) in the particular combination of events and that processes that previously were deliberately induced in others happened on their own.
Click to expand...

That makes a heck of difference, don't you think?

If her body was able to do this on its own without any other kind of transplanted cells, and that's never been seen before, to my mind, that makes her unique.

I imagine her surgeons probably want to figure out why.
 
You must log in or register to reply here.

Back
Top Bottom