Clones and organ transplants

[elfkin477]

***If ***human cloning was possible, could you donate a lobe of your liver to your young clone without having to have him/her take anti-rejection drugs? Or could you steal an organ from your clone drug-free?

I know that early kidney transplants were done without rejection drugs in identical twins, but identical twins can have tiny genetic differences so it’s possible they could reject even their twin’s organ. Are clones more or less identical to the original person than a naturally occurring identical twin?

[Chronos]

Any process of growing an organism will have some mutations. Whether an artificial clone will have more or less mutations than an identical twin will depend on how the clone is grown. If it’s grown in a human uterus and then raised like any other human, it would presumably also have the same mutation rate.

And even given those natural mutations, it’d be extremely unlikely for a person to reject an organ donated by any sort of clone, natural or artificial. The chance would be essentially the same for a person to reject their own organs, and while that can happen, it’s not really something worth worrying about.

[elfkin477]

Thanks, Chronos.

Rather than start a second thread, I want to tack a second question onto this one:

What sort of tests/scans would tell a doctor that someone’s had an organ transplant if their medical history was unknown, and they didn’t have much of a scar?

[Ranchoth]

@elfkin477

What sort of tests/scans would tell a doctor that someone’s had an organ transplant if their medical history was unknown, and they didn’t have much of a scar?

…this is assuming the donation was from a clone, right? So that the patient isn’t taking immunosuppressants?

[Broomstick]

@elfkin477

***If ***human cloning was possible, could you donate a lobe of your liver to your young clone without having to have him/her take anti-rejection drugs? Or could you steal an organ from your clone drug-free?

Yep, all of that is a yes.

I know that early kidney transplants were done without rejection drugs in identical twins, but identical twins can have tiny genetic differences so it’s possible they could reject even their twin’s organ.

As noted, it’s possible to reject your own organ, it’s called auto-immune disease, and in that case you’d also reject your twin/clone’s donated organ.

Are clones more or less identical to the original person than a naturally occurring identical twin?

Yep.

@elfkin477

What sort of tests/scans would tell a doctor that someone’s had an organ transplant if their medical history was unknown, and they didn’t have much of a scar?

You’re going to have a scar.

There are two and only two exceptions to that: blood transfusion (yes, it is an organ transplant) and bone marrow transplant. In those two cases there really isn’t anything to tell you what has occurred.

Otherwise, you WILL have a scar of some sort. When, say, every major blood vessel connecting your liver to the rest of your body has a line of stitches going completely around it that indicates it’s not original equipment.

[elfkin477]

Ranchoth, yes, the clone got the organ from their “parent” (really twin) so no immunosuppressants.

@Broomstick

Yep, all of that is a yes.
Otherwise, you WILL have a scar of some sort. When, say, every major blood vessel connecting your liver to the rest of your body has a line of stitches going completely around it that indicates it’s not original equipment.

Right, but how do you see the effects of these internal stitches? Cat-scan, MIR?

[Broomstick]

Depending on the technique and how well the person heals up, it might be anything from clearly visible on imaging to detectable only if you go inside the person with a camera.

I think for kidney transplants, though, they put the new kidney in a different location than the original - maybe in a better protected spot?

[John_Mace]

@elfkin477

Are clones more or less identical to the original person than a naturally occurring identical twin?

I guess I was the only one reading this thinking it was asking if clones would be either more or less identical.

But note that there are different types of identical twins, including Mirror Image Twins. Although genetically still identical, they may appear slightly different. You would not get this phenomenon in cloning unless you deliberately produced it, or unless your cloned blastocyst twinned into MITs.

[elfkin477]

@Broomstick

Depending on the technique and how well the person heals up, it might be anything from clearly visible on imaging to detectable only if you go inside the person with a camera.

I think for kidney transplants, though, they put the new kidney in a different location than the original - maybe in a better protected spot?

I was specifically thinking liver - an adult can transplant to a child by donating a lobe of theirs (with the bonus that theirs grows back too) and have it fit in a much tinier body.

[Ranchoth]

@Broomstick

Otherwise, you WILL have a scar of some sort. When, say, every major blood vessel connecting your liver to the rest of your body has a line of stitches going completely around it that indicates it’s not original equipment.

Hmmm…assuming the patient is deliberately trying to conceal they’ve had a clone-donor organ transplant, might it be possible to cover up the (external) surgical scar with another scar? A good burn, or road rash wound, for example? Crude, even dangerous, and it’s going to ruin your swimsuit shoot prospects, but at least able to spoof a cursory examination.

[RivkahChaya]

Clones are made by transferring the nucleus of an adult cell into an ovum, and then getting the ovum to replicate. That means that unless the donor ovum came from a maternal relative of the nucleus donor, the resultant clone would have different mitochondrial DNA from the original.

Now, I have no idea what role mitochondria plays in organ rejection, but if your goal in having yourself cloned is to have a reserve of organs, I suggest you play it safe and get a maternal relative to donate the ovum. Or do it yourself, if you are female.

On the other hand, an awful lot of kidney transplants happen for genetic diseases, so you might not want the kidney of a clone. They do happen for other reasons, such as a disease that started out as an infection, but if your genes dictate a lifespan for your kidneys of only 20 years, you’re gonna need a lot of clones, and they’re gonna have to be fine with dialysis or waiting for a cadaver kidney.

Livers fail because of hepatitis, much of the time, and that’s an infection that your clone can avoid, after giving you a donation.

Lung transplants happen a lot of the time because of genetic illnesses, like certain forms of cystic fibrosis. People who lose a lung to cancer after smoking don’t usually get on the donor list, because they first of all have to be cancer-free for a certain amount of time, and they also have to stop smoking. You would be shocked how many people undergoing treatment for emphysema, lung cancer, COPD, or who have lost a lung, or part of a lung, are still smoking. It’s mind-boggling, especially with alternate nicotine delivery systems. At any rate, if you want to smoke, and have a spare lung in your clone, you’re going to have to convince him not to smoke, the whole time you are doing it. Good luck with that.

All in all, clones may not be the best way to go. Yes, the organ will be a perfect, or near-perfect match, but in that, it may just bring with it all the problems of the original.

[Chronos]

I think that the premise here is that the clone is non-volitional, either through being deliberately modified to grow without a brain, or through forcible confinement, or both, in which case one needn’t worry about the clone engaging in risky behaviors.

[Broomstick]

@Ranchoth

Hmmm…assuming the patient is deliberately trying to conceal they’ve had a clone-donor organ transplant, might it be possible to cover up the (external) surgical scar with another scar? A good burn, or road rash wound, for example? Crude, even dangerous, and it’s going to ruin your swimsuit shoot prospects, but at least able to spoof a cursory examination.

I think these days a decent tattoo would be the preferred method.

[RivkahChaya]

@Chronos

I think that the premise here is that the clone is non-volitional, either through being deliberately modified to grow without a brain, or through forcible confinement, or both, in which case one needn’t worry about the clone engaging in risky behaviors.

It’s going to be hard to keep something alive with healthy organs without a brain. You need a brain to tell your body when to release hormones that, among many other functions, direct digestion and metabolism. Also, you need to move around to have a healthy blood flow. You wouldn’t want an organ transplant from someone you has been lying in a bed, brainless, with its metabolic processes controlled by injecting hormones, or giving them through a gastric tube.

[elfkin477]

@Chronos

I think that the premise here is that the clone is non-volitional, either through being deliberately modified to grow without a brain, or through forcible confinement, or both, in which case one needn’t worry about the clone engaging in risky behaviors.

Nah. The clone is a baby, and like cloned animals (remember why Dolly the sheep died young?), he experiences early organ failure, and his adult “twin” unwillingly gave up part of his liver for him and didn’t remember later. There are aliens involved too… uh, I think people realize this is about a story, but if not you do now.

[Ranchoth]

@RivkahChaya

It’s going to be hard to keep something alive with healthy organs without a brain. You need a brain to tell your body when to release hormones that, among many other functions, direct digestion and metabolism. Also, you need to move around to have a healthy blood flow. You wouldn’t want an organ transplant from someone you has been lying in a bed, brainless, with its metabolic processes controlled by injecting hormones, or giving them through a gastric tube.

Want to see something hideous? I’ve seen a report of a child who survived being born with only a brain stem for three years, before dying of an infection. 'Wasn’t even confined to a bed—well, as much as “being rolled around in a stroller or propped up sitting” counts as “not bedridden.” :eek:

“Survived” and “child” also being somewhat relative terms, really. The point being, apparently surprisingly good results could be achieved by engineering away—or removing—the right portions of brain.

[md2000]

Identical twins are clones. They may or may not have identical mitochondrial DNA but definitely overlapping, unlike a clone based on only nucleus material. Mitochondrial DNA (IIRC) are free-floating chunks of DNA (rings?) in the cell not bound into the nucleus. Identical twins happen when sometime in the process, the fertilized egg splits into two chunks which develop separately into complete human beings. Each set of cell(s) may or may not have all of the original - luck of the draw.

So anything that can happen between twins - missing important mitochondrial DNA, minor mutations after the duplication of genetic material, etc. - are the same as for artificial clones. The only danger(?) is that a sample taken from an adult and cloned, as mentioned previously, has the excess telomeres(?) that accumulate with age, making the clone older from the start, and the risk that adult’s sample is also genetically drifted from the original (probably a bigger risk than between two same-age clone/identical twins.)

[RivkahChaya]

@Ranchoth

Want to see something hideous? I’ve seen a report of a child who survived being born with only a brain stem for three years, before dying of an infection. 'Wasn’t even confined to a bed—well, as much as “being rolled around in a stroller or propped up sitting” counts as “not bedridden.” :eek:

“Survived” and “child” also being somewhat relative terms, really. The point being, apparently surprisingly good results could be achieved by engineering away—or removing—the right portions of brain.

His name was Nicholas Coke, and he required gastric tube feeding, and numerous injections every day, to make up for the fact that his missing brain couldn’t send signals to his endocrine system. But his mother was very proud of the fact that he was “never hooked up to machines.”

He had a relatively normal looking head; it was small, but he had a cranial vault, and didn’t have the bulging eyes you see in anencephaly, so he probably had something like hydrancephaly. The brain starts developing normally in utero, but atrophies, probably because something interferes with its blood supply, and the space in the cranium fills with fluid.

You can find all manner of youtube videos, and archives from Christian networks calling him the “miracle” baby; his parents claim he reacted differently to familiar people, but I’m highly skeptical, especially since they also describe him as “loving.”

Personally, I think the “never hooked up to machines” comments are a huge insult to people with normal brains who require ventilators after spinal cord injuries or infections.

[Chronos]

Mitochondrial DNA isn’t free-floating. It’s bound up in the mitochondria, which were originally independent bacteria-like organisms which took up residence inside our ancestors’ cells, and ended up in a commensalistic relationship since they could process sugars far more efficiently than their host cells could. Now, they’re basically organelles and an inseparable part of the cell, but they still retain that DNA as a legacy of the time when they were independent. All of the mitochondria in any given cell, or indeed in any given organism, have identical DNA (other than the occasional stray mutation), and so identical twins would also be identical in their mDNA.

[Broomstick]

Identical twins, yes, but artificial cloning can be different if you use nuclear DNA in a donor egg cell. In such a case the older DNA donor and the younger clone would have different mDNA, unless the donated egg also came from the DNA donor.

It still shouldn’t affect organ donation, though, since as far as I know mDNA is not a factor in the immune reactions that affect whether a donated organ is rejected or accepted by the body.