[HN Gopher] U.S. surgeons transplant pig heart into human patient
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U.S. surgeons transplant pig heart into human patient
Author : danso
Score : 123 points
Date : 2022-01-10 21:32 UTC (1 hours ago)
(HTM) web link (apnews.com)
(TXT) w3m dump (apnews.com)
| terramex wrote:
| The biggest surprise for me is that organ transplant from animals
| had been attempted in the past, I was sure it had not been done
| yet.
|
| Apparently there was a newborn that lived for 21 days with baboon
| heart in 1984: https://en.wikipedia.org/wiki/Baby_Fae
|
| Wikipedia ( https://en.wikipedia.org/wiki/Xenotransplantation )
| also lists one successful kidney transplant from chimpanzee in
| 1964:
|
| > Out of 13 such transplants performed by Keith Reemtsma, one
| kidney recipient lived for 9 months, returning to work as a
| schoolteacher. At autopsy, the chimpanzee kidneys appeared normal
| and showed no signs of acute or chronic rejection.
| wizzwizz4 wrote:
| This reminds me of the 1997 book _Pig Heart Boy_ by Malorie
| Blackman.
| tricky wrote:
| You might be asking, why a pig? I don't know, but forever ago I
| wrote software for a cardiovascular imaging lab and pigs were
| their primary test subjects. I was like, "why pigs?" and the PI
| was like, "Imaging-wise, pig hearts aren't too different from
| humans. Plus, we can give them a heart attack in the scanner and
| not go to jail. Some labs use dogs. I just can't do that."
| dexwiz wrote:
| Pigs are really common in biomedical testing. They are
| physically a similar size and weight to humans. They also reach
| maturity in about 6 months. Much cheaper to raise than
| primates, and more likely to get approval for testing. My
| friends in biomed grad school named one of theirs cyber pig
| because it has about 30 different experiments ran on it before
| it was killed, and afterwards it was portioned out for further
| tests.
| ardit33 wrote:
| I heard they are humanized 'pigs'. Ie. engineered so their
| organs don't trigger our immune system. Not sure how true is
| this, or it is just a myth.
| decebalus1 wrote:
| Careful with that. You might end up with pigoons [1]
|
| [1] https://en.wikipedia.org/wiki/Oryx_and_Crake
| Finnucane wrote:
| The article states they changed a sugar that triggered
| rejection.
| pazimzadeh wrote:
| Exactly:
|
| "More than 95% of human anti-pig antibodies are directed
| against 3 pig carbohydrates: Gal 1 to 3aGal ([?]80%-90%),7
| Neu5Gc ([?]5%-15%),8 and b4Gal (1%-5%)"
|
| "To reduce anti-pig antibody binding to the xenograft, the
| 3 principal carbohydrate antigen targets have each been
| successfully removed from pigs by gene knockout (KO)
| (Figure 3)"
|
| Progress Toward Cardiac Xenotransplantation
| https://www.ncbi.nlm.nih.gov/labs/pmc/articles/PMC7990044/
| shagie wrote:
| The Alpha Gal sugar.
|
| https://www.wnycstudios.org/podcasts/radiolab/articles/alpha.
| .. and https://www.wnycstudios.org/podcasts/radiolab/articles
| /retur... are good listens on the subject.
|
| In particular from the second one:
|
| > SOREN: Which brings me back to that little part of the
| article that piqued my interest in the beginning, because the
| pig that they got the kidney from to do this was a very
| special pig. Normally, pigs and other mammals that aren't
| primates have a sugar in their body that our bodies don't
| have, and so we don't like it or see it as foreign. And
| that's why usually an organ from another animal would get
| rejected. But this pig had been genetically modified. It had
| had the gene that makes that sugar removed, so it didn't have
| that sugar. Which is part of the reason this worked. And that
| sugar just so happens to be called "alpha-gal."
| Victerius wrote:
| What ... happens to the pigs who get accidental heart attacks?
| Are they ...? Do they ...?
| ricc wrote:
| Yes
| valachio wrote:
| They end up on my dinner plate as a delicious high-protein
| meal.
| hellbannedguy wrote:
| meepmorp wrote:
| They get rushed to a special hospital for pigs and then go to
| live long happy lives with other porcine MI survivors on a
| farm far, far away.
| Qem wrote:
| I wonder, in the best case, how long a pig heart is expected to
| last, given pigs have shorter lifespans than humans. Wish the
| patient good luck.
| samwillis wrote:
| When I was a teenager there was a novel adapted for TV by the BBC
| called "Pig Heart Boy". It explored the emotional impact of this
| type of procedure on a teenager and the response from the public,
| both good and bad. I don't remember much about it but it looks
| like it won a BAFTA.
|
| https://en.m.wikipedia.org/wiki/Pig_Heart_Boy
| belter wrote:
| "Pig Heart Boy (1999)" https://youtu.be/JoBW_XCWDDA
| geocrasher wrote:
| Piglet is Public Domain for a WEEK and they're already harvesting
| his organs.
| kiba wrote:
| We're getting good at building artificial nonorganic heart, still
| a bit away from growing conventional hearts.
|
| I wonder how these future options intersect, whether one will win
| out over another, or we will be having hybrids?
|
| Electromagnetic motors work fine, but a big issue with them is
| the method of powering them and maybe biocompatibility issue.
|
| Normal organic hearts don't have this disadvantage but their
| downside is that they are in its infancy?
| soco wrote:
| One word: 3D printing. Ok that was two words, but still
| exciting.
| josephcsible wrote:
| I wonder why an artificial heart wasn't an option here.
| blakesterz wrote:
| Other places that are reporting on him say "He was deemed
| ineligible for an artificial heart pump due to uncontrollable
| arrhythmia."
| rzzzt wrote:
| I jumped onto Wikipedia to figure out why arrhytmia might be
| a problem, and it looks like "artificial heart pump" might
| stand for a VAD (Ventricular Assist Device), as in it pumps
| blood and it helps, but the original organ remains in
| circuit.
| [deleted]
| mhb wrote:
| It seems like those are not quite there yet: How to Build an
| Artificial Heart
| https://www.newyorker.com/magazine/2021/03/08/how-to-build-a...
| josephcsible wrote:
| A bunch of people do have artificial hearts. I'm wondering
| what about this patient made one not suitable for him.
| bogwog wrote:
| Maybe cost? Those things ain't cheap.
| virtue3 wrote:
| "The patient, David Bennett, 57, knew there was no guarantee
| the experiment would work but he was dying, ineligible for a
| human heart transplant and had no other option, his son told
| The Associated Press."
| josephcsible wrote:
| Yes, "had no other option" confirms that an artificial heart
| wasn't an option, but it doesn't say _why_ it wasn 't.
| totally wrote:
| Yes, it doesn't say _why_ it wasn 't.
| JohnPrine wrote:
| Yeah!
| TulliusCicero wrote:
| I wonder if it's possible that a pig heart might actually be
| better than an artificial one? I don't know enough about the
| state of the art in either to even guess myself.
| woke_neoliberal wrote:
| The pig was modified to remove presentation of immunogenic sugars
| on the cell surface. Unfortunately, the recipient needs to be on
| immunosuppressants the rest of their life.
|
| This rekindles discussions back in school about chimeras... in
| order for the organs to be immunocompatible, the donor needs to
| be partially human. What % is too human to harvest for organs?
|
| I suppose it's still too soon to answer such questions, but
| apparently, 0% acceptable.
| badRNG wrote:
| I don't think it is all that uncommon for regular human-to-
| human transplant recipients to be on immunosuppressants for
| life. If I'm not mistaken, that's the case for all organ
| recipients, but there may be exceptions. I think the concept of
| "immunocompatibility" can refer to a spectrum of outcomes that
| we haven't gotten down even for transplants within our own
| species.
| majormajor wrote:
| What part do you think opens that door?
|
| Human organ recipients also need immunosuppressants forever,
| outside of rare cases. This particular case sounds like a very
| small modification to the source pig, not a pig carrying a
| human organ.
| dnautics wrote:
| > What % is too human to harvest for organs
|
| I don't think it's really measurable, because a meaningful "%"
| implies a relatively context-free, relatively uniformly
| distributed importance to genetic sequence.
|
| The most immunogenic sugar is glycolylneuraminic acid. Humans
| are incapable of making this sugar so it's immediately
| recognizable as alien by the human immune system.
|
| You could in theory disable production of this sugar with a
| single base pair mutation which (if that's how you did it)
| would make this .000001% sequence difference extremely
| important over almost any other sequence point.
|
| As a side note it's a matter of speculation that the lack of
| this sugar is an evasion mechanism for species-jumping flu.
|
| Edit: tick thing was wrong, I had misremembered! Thank you
| smart reader who has since deleted their comment calling me
| out.
| [deleted]
| robbiep wrote:
| They're not making the pig more human, they're removing the
| markers of 'foreign' that would make it an immune target. So
| it's a nice vanilla organ that minimally attracts the attention
| of the immune system.
| 323 wrote:
| Just removing some sugars can't possibly work, since the pig
| heart will lack correct MHC class I molecules, which will
| make it a target. So the patient will need permanent immune-
| suppression.
| dnautics wrote:
| On the other hand (and I am being flippant... Slightly) how
| do you know that removing this one gene doesn't unlock
| consciousness?
| JumpCrisscross wrote:
| > _how do you know that removing this one gene doesn 't
| unlock consciousness?_
|
| The words you're looking for are sentience or even
| sapience.
| pazimzadeh wrote:
| A weird idea but possible. Although it wasn't one of the
| genes targeted in this study, humans are the only animals
| which have the Neu4Ac form of the sialic acid sugar,
| instead of Neu5Ac, and the brain is one of the regions that
| is most heavily sialiated in humans and could be one of the
| things that sets us apart.
|
| https://www.ncbi.nlm.nih.gov/labs/pmc/articles/PMC7153325/
| TulliusCicero wrote:
| I mean pigs are already "conscious" on some level, I'm
| sure.
| serf wrote:
| >how do you know that removing this one gene doesn't unlock
| consciousness?
|
| i'm not the poster you're replying to, but for me the
| answer is this :
|
| consciousness appears to me to be a constellation of traits
| rather than a trait itself that would be easily acquired
| with a genetic shift.
|
| One could then say : 'What if the one we flip is the thing
| that finishes the constellation of traits that activates
| consciousness?' , and sadly I must confess that I believe
| that if that were to happen to an entity without sufficient
| communications methods that it would probably remain
| unknown and subject to whatever experiences whatever
| sensory organs it may have provides it, while we remain
| entirely unaware for some time.
|
| Also, a point that I agree upon by the poster who replied
| to you with me ; we don't seem to hold conscious entities
| in very high regard -- only human ones.
| ioseph wrote:
| I'd definitely think of pigs conscious given they can play
| video games: https://www.bbc.com/news/technology-56023720
| TulliusCicero wrote:
| According to another article: https://www.usatoday.com/story/
| news/health/2022/01/10/human-...
|
| > Three genes were turned off that might otherwise have
| triggered an immediate immune rejection - the recognition of
| a pig organ as coming from a different species. Six human
| genes were added to prevent blood from coagulating in the
| heart, improve molecular compatibility and reduce the risk of
| rejection.
|
| > One final gene was turned off to keep the pig from growing
| too large.
|
| So they actually did make the pig a tiny bit human.
| davidhyde wrote:
| If it gets you one degree closer to Kevin it's worth it.
| MichaelRazum wrote:
| The pig life expectancy is about 12-18 years. Does it mean that
| the heart will work about so long?
| andrewflnr wrote:
| Only if the heart is the first thing that goes on a pig.
| pm90 wrote:
| Not necessarily. Life expectancy is affected by the most mortal
| part of your species: it might be that pigs' hearts are fine,
| but they're prone to cancers after a certain age.
| dukeofdoom wrote:
| So..."human pig hybrid".
|
| How full is the tip jar for things Alex Jones was right about. If
| you grant him some room for hyperbole and exaggeration guy is a
| pretty good futurist. He brags about reading research papers all
| day long. Fascinating role as a court jester and modern day
| prophet.
| hwbehrens wrote:
| If pigs (or any animal) broaden the compatibility to other
| organs, what are the ethical implications for raising them with
| the intention to harvest their organs, if any?
|
| On one hand, we already raise pigs to kill and eat routinely, and
| (mostly) people don't care - is this any different than say,
| buying a pig heart at the market to eat?
|
| On the other hand, it does somehow feel different to me, perhaps
| because sharing organs somehow humanizes the pigs by emphasizing
| our similarity? I'm not entirely sure from where my hesitation
| stems.
|
| I'm curious if anyone else read this story with mixed reactions.
| monkeybutton wrote:
| What about growing human organs in pigs? Like the pigoons from
| Oryx and Crake.
|
| http://www.technovelgy.com/ct/content.asp?Bnum=1177
| TulliusCicero wrote:
| Then you have the reverse problem of the pigs rejecting the
| human organs, I suppose.
| zanethomas wrote:
| Eat all the bacon you want, get heart disease, get new heart,
| eat more bacon.
| TulliusCicero wrote:
| > On one hand, we already raise pigs to kill and eat routinely,
| and (mostly) people don't care - is this any different than
| say, buying a pig heart at the market to eat?
|
| Yes, in that it's morally superior to eating meat. Eating meat
| is mostly a nutritional luxury, but needing functioning organs
| is not. I'm a meat eater, but I imagine there are a number of
| vegetarians who would be okay with this sort of organ
| harvesting process.
|
| Of course, if we end up able to grow organs in a lab
| environment instead of inside an animal, that's probably better
| for all involved.
| GiorgioG wrote:
| > what are the ethical implications for raising them with the
| intention to harvest their organs, if any?
|
| We slaughter more than 100m pigs per year in the US for food. I
| don't think a few more million are going to cause a moral
| dilemma.
| drooby wrote:
| Don't you know? Humans are pigs. /s
|
| Interesting and wild hypothesis.
| http://www.macroevolution.net/human-origins.html
| LoveMortuus wrote:
| Finally! I wonder how much would it cost me to have car ears
| transplanted!
| kingsloi wrote:
| Interesting that it's a pig heart!
|
| I was introduced into "pig bladder ground up into magical pixie
| dust" aka ACell (https://en.wikipedia.org/wiki/ACell) when it was
| used to treat my child's heart surgery incision. I was super
| surprised how well it worked and how quick, too!
| xtracto wrote:
| I read about the "magical pixie dust" in a very old Time
| Magazine (that my dad had a subscription to). Since then, I
| have always dreamed of having the tip of my left thumb
| "regrown" using that or a similar technology. Glad to know that
| it is being used more commonly on nowadays.
| peanut_worm wrote:
| If a pigs heart was beating in my chest I dont think I would ever
| be able to relax again
| lr4444lr wrote:
| Considering how much eaten slop and adipose tissue it's evolved
| responsible for dealing with, I'd actually be pretty hopeful.
| bogwog wrote:
| It beats dying. (pun intended)
| notahacker wrote:
| To be fair, pigs generally seem much more relaxed animals than
| humans. Will happily eat pork too for that matter. I'd just
| find some nice mud to roll in.
| Buttons840 wrote:
| I suspect this guy has already come to terms with death.
| Dumblydorr wrote:
| At least you would continue to exist!
| ballenf wrote:
| I'm only able to relax when I don't think about my need for a
| constantly beating heart -- pig or otherwise.
| peanut_worm wrote:
| Same, I start to panic if I think about my heart or
| circulatory system for more than a few seconds
| basementcat wrote:
| Rest assured that if you were ever in a potential cannibalism
| scenario, at least a part of you (if prepared appropriately)
| might taste like bacon.
| tonyedgecombe wrote:
| I might not be able to eat bacon again.
| SavantIdiot wrote:
| This is great news.
|
| The organ donor wait list is 6-8 years for most organs (kidneys,
| livers, etc.).
|
| Please be an organ donor.
| oversocialized wrote:
| planetsprite wrote:
| One step closer to Porkin' Across America irl
| melling wrote:
| "The Maryland surgeons used a heart from a pig that had undergone
| gene-editing to remove a sugar in its cells that's responsible
| for that hyper-fast organ rejection."
|
| So, we need to genetically engineer the animals
| Vrondi wrote:
| We just need to grow the organs in the lab.
| trwhite wrote:
| A sad sign of what things have come to when a man's last hope at
| survival is a pig heart.
| p_j_w wrote:
| Maybe I'm missing something, but what's so sad about this
| situation versus the past? In the past, he would have just
| died, but "what things have come to" is that medical technology
| has advanced to the point where he has a shot of making it
| another few years.
| Ensorceled wrote:
| Reminder: We've been replacing human heart VALVES with pig valves
| for a long time now. My grandmother lived for almost a decade
| after her replacement.
|
| https://www.heart-valve-surgery.com/learning/pig-valve-repla...
| livinglist wrote:
| May I ask how much did it cost and did insurance cover it?
| OminousWeapons wrote:
| A surgical aortic valve replacement (SAVR) for example will
| cost ~50K I believe? It will be covered by insurance if it is
| necessary.
|
| There are also less invasive forms of valve replacement
| (transcatheter / percutaneous) which involve collapsing a
| synthetic valve around a balloon at the end of a catheter,
| inserting the assembly into a femoral artery, guiding the
| valve into the heart and into the open damaged valve, and
| then inflating the balloon and deploying the new valve inside
| of the damaged old valve. In SAVR the old valve is removed
| and the new one is sewn in. In transcatheter aortic valve
| replacement (TAVR), the old valve is held open by the new
| valve.
| frumper wrote:
| Not OP, but my dad was offered either a mechanical or pig
| valve when he had a bypass surgery done. Both were covered by
| insurance, I don't know which cost more, but he hit his
| deductible either way.
| dnautics wrote:
| I could be wrong but I believe those valves are harvested for
| their cartilagenous (non-alive) components, their cells
| stripped, the valves throughly cleaned, and implanted in place.
| This is not quite the same as implanting an organ with live
| cells autonomously producing potential antigens on a daily
| basis
| TulliusCicero wrote:
| According to another article, that was also true of this
| patient.
| garren wrote:
| I wonder why a pig heart rather than one from another primate?
| The article mentions a baboon heart in an earlier attempt at
| xenotransplantation with an infant. Is a pig's heart as, or more,
| compatible or is it more a matter of availability?
| reaperducer wrote:
| IANAD, but from what I remember back when trans-species heart
| transplant research started in the 80's, it was that pig heart
| tissue is most similar to human heart tissue.
|
| Hopefully there is a D on HN who can explain better.
| [deleted]
| dotnet00 wrote:
| Pigs are very anatomically similar to humans but due to being a
| food source there were probably also fewer ethical concerns
| compared to using primates.
| Supermancho wrote:
| At age 2, I was a candidate for a monkey heart transplant, as I
| had a perforated aortic valve and surgery on tissue with the
| consistency of wet-toilet paper in an infant had a very high
| mortality rate (the girl on the table before I went in had
| died). My parents declined the monkey transplant. Good thing.
| The intended recipients of multiple attempts at the monkey
| hearts, died. I eventually received a primitive mechanical
| implant, which I quickly outgrew. By the 80s I had another
| surgery to replace it (https://en.wikipedia.org/wiki/Bj%C3%B6rk
| %E2%80%93Shiley_valv...). This had it's own dangers, as the
| strut would fail along 2 ends of a sizing graph (most people
| were at the larger size end). I sat safely on the bell curve. I
| kept that into my 30s which caused various problems with the
| aortic stem and thickening of the left ventricle.
|
| Now I'm rocking the On-X, which is superior in innumerable
| ways.
| gus_massa wrote:
| People love primates, specially big ones, and will get angry if
| in the future thousands of primates are used for organ harvest.
|
| Pigs? People will make jokes like " _If I pay for the heart
| transplant, do I get a free bacon?_ "
|
| (Also, pigs have the correct size to get an organ usable in
| humans.)
| fogihujy wrote:
| Also, while pigs are naturally curious and definitely aren't
| dumb, I suspect our primate cousins are closer to us on the
| conciousness scale.
|
| And yes, bacon. Combine the transplant with an offer on cheap
| pork, and we'll soon have heart transplants and bacon
| deliveries as a service. :D
| joeblow21 wrote:
| Simon_O_Rourke wrote:
| The poor guy, not only is he on immunosuppressant drugs for the
| rest of his days, but he's a new type of walking transgenic
| disease vector.
| lr4444lr wrote:
| Beats dying in vain wait for a donor.
| Ensorceled wrote:
| Lucky guy isn't dead!
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