New Discovery May End Transplant Rejection 201
mmmscience writes with this excerpt from the Examiner:
"Big news in the medical world: scientists in Australia have found a way to stop the body from attacking organ transplants, greatly decreasing the possibility of organ rejection. ... When a new tissue is introduced, one's immune system kicks into overdrive, sending out cells known as killer T cells to attack and destroy the unknown tissue. ... Professor Jonathan Sprent and Dr. Kylie Webster from Sydney's Garvan Institute of Medical Research focused on a different type of T cells — known as regulatory T cells (Treg) — in this study. Tregs are capable of quieting the immune system, stopping the killer T cells from seeking out and attacking foreign objects."
Re:So they're doing another type of immunosupressi (Score:5, Informative)
But it only is needed for 2-3 weeks, according to the article. Just long enough for the body to accept the new cells, after that they let things go back to normal, which would allow the body to attach infectious agents.
Re:So they're doing another type of immunosupressi (Score:5, Informative)
The idea (as I understand it) is this:
1) Immunosuppressants not only lower your defenses but are also toxic (as with many drugs).
2) I assume the treatment is either non-toxic, or at least not as bad for you.
3) Not sure about this: I think that people need to take immunosuppressants for a LONG time after the transplant, thus pumping in toxins AND keeping the defenses low, where as this idea is a one time thing you do before the transplant and are then done with.
The wording also makes it sound like the rejection rate is lower than usual, I am unsure if this is true or not.
So yes, you still have the lowered defenses, but with out the toxins, and possibly for a shorter time.
This (Score:3, Informative)
Re:Wait.... (Score:4, Informative)
I assume you were goign to say "we might know how to reverse it".
The answer is fairly simple:
We are giving (and have been for a long time) people something like AIDS, not AIDS itself as that is a condition directly linked to HIV (even though the name makes it sound like it would be any time when you acquire a immune deficiency). It isn't AIDS we need a treatment for, it is HIV.
Re:Organlegging (Score:4, Informative)
You missed the GP poster who was referring to the act of people effectively abducting humans for the sole purpose of harvesting their organs. In the case of kidneys they could take 1, leave the remaining one be, and send the poor sod on their way, but more likely the person would simply be killed and their organs sold to the highest bidder.
The only reason that doesn't happen so much now (except potentially in China, to an extent) is due to the whole organ rejection thing. No good putting 'Type X' kidneys on the market if all your prospective clients within a reasonable distance need 'Type Y'.. and short of getting medical records on everybody, you can't see on the outside what type organ the person has.
With that out of the way, let the random killings and organ harvests begin.
( 'Organlegging'.. *sigh* Niven. )
Re:has its drawbacks? (Score:3, Informative)
Re:Wait.... (Score:3, Informative)
Re:...if... (Score:4, Informative)
Actually, the article includes most of those.
Re:So they're doing another type of immunosupressi (Score:4, Informative)
"3) Not sure about this: I think that people need to take immunosuppressants for a LONG time after the transplant"
AFAIK ('tho there're bound to be exceptions maybe?) - you take them for as long as you don't want your immune system to attack the new organ, which'll basically be, for the rest of your life.
Horrible Article (Score:5, Informative)
For starters "killer T-cells" are usually referred to as NK-cells and they are NOT thought to be part of the normal rejection process (they do not require activation and thus would no be stopped by immunosuppresion). There are three types of rejection hyperacute (pre-formed antibodies attack the organ in minutes - the organ literally dies as soon as it is transplanted - this is avoided by the "matching" process), acute (where T-cells [not NK-cells] attack the organ since it is not "self" and therefore "bad" - this is where immunosuppresion helps) and chronic (the body slowly rejects by allowing fibrosis of the vessels leading to the organ).
Actual survival statics for all kidney allografts exceeds 95% today. 80% is quite a drop!
Grafts are not assumed to "take" after 100 days allowing us to stop immunosuppresion! Immunosuppression is currently LIFELONG. There are a few instances where people have tolerated a non-identical twin transplant without medications, but this is _very_ rare. There is active research into finding the key to allow "tolerance" whereby we can drop the medications, but this is still early.
IL-2 suppression is the _mainstay_ of current immunosuppressants both blocking its production via calcineurin ihibitors (cyclosporin and tacrolimus), inhibiting the response (sirolimus/rapamune), or by blocking the receptor with antibodies (basiliximab/daclizumab). (Please understand this is only about half of the therapies that are in use for immunosuppresion, I'm just focusing on the Il-2 aspect).
Just followed the second link and it is _much better_. Still, I strongly disagree with their assertions of 100 days, just doesn't happen in humans. Apparently this study is using IL-2 STIMULATION with a complex that attempts to increase the regulatory T-cells...To me this means that this treatment will not co-exist with the current immunopupression dogma... this means that they will have to have a "complete" replacement for immunosuppresion they won't be able to add this to the current regiment and that means this treatment protocol will be quite sometime in the pipeline. And (fortunately) the authors acknowledge that they are optimistic, but aren't rushing off to collect their Nobel yet:
I am also aware that effective approaches in mice do not necessarily give good results in humans because of subtle differences in the immune systems of mouse and man.
Re:Organlegging (Score:3, Informative)
Probably, we'll soon be able to grow artificial organs from IPSC (Induced Pluripotent Stem Cells). So the whole question might become moot very fast.
As it happened in Niven's Universe :)
Re:Organlegging (Score:3, Informative)
Actually, that's not true. With kidneys and a few other organs, no typing is necessary before hand. The immunosuppressants are so good these days that a completely non-matching kidney is just fine.
There's some other tissues that for various reasons still requires a close match
Re:So they're doing another type of immunosupressi (Score:5, Informative)
I got a kidney transplant in 1995, and I will be on anti-rejection drugs until either 1) I die, 2) something better comes along that doesn't require anti-rejection meds anymore (<crosses fingers>), 3) or I reject the kidney and it is removed.
Autoimmune Disorders (Score:5, Informative)
This is better news than they even let on. A means to control rejection is the same as a means to control autoimmune disorders. Recent evidence supporting this is at http://www.ncbi.nlm.nih.gov/pubmed/19199937 [nih.gov] There's a partial list of such disorders at http://en.wikipedia.org/wiki/Autoimmune_disease [wikipedia.org]
Knowing the mechanism for increasing Treg leads to understanding the mechanism for controlling, thus including suppressing Treg. That would boost the body's immune response. It could control (though not cure) AIDS, and lead to treatments of such as hepatitis B or C without requiring the very side effect laden pegylated alfa interferon 2 + ribavirin treatment. Inducing autoimmnune disease has already been suggested as a cancer treatment http://www.pnas.org/content/96/10/5340.full [pnas.org]
As explained in http://en.wikipedia.org/wiki/Immune_system [wikipedia.org] an immune system is a very complex system with many components that interact. The more of these we can manipulate the closer we get to the kind of treatments suggested above.
Re:So they're doing another type of immunosupressi (Score:5, Informative)
I am a transplant surgeon (Score:1, Informative)
This is not news. It has been possible to produce indefinite allograft survival in mice and rats since at least the 1960s.
Current immunosuppression is very effective - less than 2% of transplanted organs fail in the first year from rejection (some fail for other reasons).
One year kidney allograft survival is currently around 95% with an optimal graft (i.e. a living donor kidney).
Current immunosuppression does have some risks and side effects. They are not trivial but not as big a deal as the general population assumes. Transplant recipients are nowhere near as immunocompromised as patients receiving high-dose cytotoxic chemotherapy, for example.
David Bruce
Re:So they're doing another type of immunosupressi (Score:4, Informative)
I'm guessing the problem isn't that sterilizing a place is so expensive. There would be the increased cost of doing buisness in a sterile place (autoclaving absolutely everything, scrubbing and suiting up if you're entering), but the two biggest costs by far I would assume to be verifying the cleanliness and (even bigger) liability and insurance for failure to maintain sterility.
I worked at a large phamecutical plant on a microbiology team ensuring that their clean room facilities were actually clean. Extremely boring work, but the worst part was that if and when you messed up (even in a trivial way like not using fresh batteries on the fans to sample the air for bacterial growth every single time) there was a mountain of paperwork to be filled out, explaining why you failed, how you're going to ensure you don't fail again, and assesing whether or not it was going to compromise anything important. An absurd amount of red tape. The actual monitoring of the sterility was extremely easy.
So that's a gigantic cost right there. I know nothing about the liability side to it other than I'm sure there are thousands of lawyers who would salivate at the thought of a patient dying after a transplant because of an infection during the 2 week sterile cycle.
And keep in mind that hospitals charge you about 10 dollars for an asprin...
Re:More complex transplants will be routine? (Score:1, Informative)
Don't donate to those suffering from adult onset diabetes. It is caused by poor diet. Those bastards get what they deserve.
etc.!
Re:So they're doing another type of immunosupressi (Score:1, Informative)
I'm currently being treated for a brain tumor with the chemotherapy drug Temodar. The cost of the initial course of the drug was about $12,000. This was for a low dose while undergoing radiation treatment after surgery. After the radiation treatments were over with, I have to take a 5 day course of the drug each month at a much higher dose. Each of these monthly courses runs about $5,000 to $7,000 and there are some pretty nasty side effects, but hopefully the drug will kill off, or at least keep any possible remnants of the tumor in check, but there are no guarantees.
I'm now able to get the drug for free through a program that the manufacturer offers, but I had to pay my 25 percent copay on prescriptions until I was accepted into the program. The copays alone ran nearly $500 a week, which was more than I was getting through my short-term disability insurance at work.