More evidence emerges for 'transmissible Alzheimer's' theory | Hacker News Reader

More evidence emerges for 'transmissible Alzheimer's' theory

nature.com

171 pointsrandomname233 comments

Somewhat misleading headline; critical quote from the article: "Neither study implies that Alzheimer’s disease could ever be transmitted through normal contact with caretakers or family members, the scientists emphasize."

This study purely covered transmission via a specific kind of transplant. Still important for understanding the disease, though.

But another critical part is that this might be transmitted by surgical instruments, which apparently can not be cleaned well enough.

That would be huge if true.

> surgical instruments, which apparently can not be cleaned well enough.

It's a problem. Previous discussion: https://news.ycombinator.com/item?id=10171077

This isn't true, many surgical instruments are disposed after use. Here is a picture of a needle: http://forums.steroid.com/attachments/anabolic-steroids-ques...

The last picture in that set is at a higher magnification than the three others.

> many surgical instruments are disposed after use

What do you mean "isn't true", what about the ones that aren't disposed of?

Since some are disposed of, that means I should somehow not worry about that ones that aren't?

And that picture is misleading.

>transmitted by surgical instrument

I admit am a biology noob, but doesn't that imply that the cause is a Virus/bacteria or some sort of agent?

That's what this article is claiming. Too early to really know.

And it might be like a prion: A bad protein, rather than a living organism.

And prions are for some reason really hard to kill. Autoclaving only "somewhat" deactivates them.

https://en.wikipedia.org/wiki/Prion#Sterilization

Both this result and the preceding paper are also entirely consistent with the hypotheses that:

1) People who are susceptible to vCJD are more susceptible to AD

2) The (cellular) stress caused by vCJD increases susceptibility for AD

3) People who have had brain surgery (a traumatic and stressful experience in terms of brain swelling) are more susceptible to AD

All three of which would be entirely inline with the fields' current way of thinking about AD, proteostasis, CBI etc. Which is not to say I actually don't think that there is a transmissible element, but I think we should avoid jumping to conclusions...

But what about the CJD controls that didn't receive transplants derived from cadaver tissue? Those didn't show the same rate of Alzheimers-like plaques, if I understood the report correctly.

The CJD controls had sporadic (sCJD), not variant CJD (vCJD) (whether or not these are distinct diseases is certainly an open question - I'm more trying to make the point that there are a lot of variables up in the air, and while it's a striking relationship there are other equally striking relationships one could draw).

A good note of caution for any study.

Does this improve the likelihood that it is treatable?

Some previous theories had been that Alzheimer's was essentially genetic. But never fully genetic, instead of guaranteeing your chance of getting it, it just increases the likelihood.

So my question is: Could this hint at Alzheimer's being the result of some yet undetected infection in the brain that some people are more prone to due to genetics, and that is transmitted due to brain tissue sharing?

PS - What I am asking about isn't that far from the latest research, see: http://www.medscape.com/viewarticle/574944_4

Or maybe an alternate type disease that is hard to detect like mad cow disease.

There is some ongoing research as well to establish whether or not AZ is a form a brain diabetes. But at this stage the amyloid hypothesis is still considered the most probable.

My understanding was that they weren't separate hypotheses but one. I thought amyloid beta interrupted insulin signalling which then lead to all of the downstream effects of neuroinflammation, cell death, oxidative stress, glutamate toxicity, etc etc.

But I've never been super clear on the type 3 diabetes explanation.

Anecdotally, I am aware that many in my family who developed alzheimer's (it runs on both side of my family) has surgery a few years before the disease started to present itself. Though the likelihood of there being much of a connection seems far fetched, even with this latest evidence, I have suddenly become much more concerned about going under the knife until this is all worked out. The grafts I get, but that proteins lingering on equipment, which isn't ordinarily removed through standard sterilization, could be a means of transmission... scary.

I'd be cautious about relying on anecdotal data here. This may be a bit like the "my kid got autism after vaccines" confirmation bias issue - as people get older, they're more likely to need surgical interventions.

These cases involved brain tissues. So unless you're having brain surgery done, there are other more mundane complications to worry about.

Course there are prion diseases which can be spread by ingesting infected nervous system tissue. Kuru, Mad cow disease and scrapie come to mind.

The long term effects of surgery are just coming to light. While, obviously, it is better to have an operation than die, it seems that you don't recover as quickly as your meat heals.

Anecdotal I know but I believe it took me 10 years to get over my bowel resection.

And then there's the anesthesia : http://www.scientificamerican.com/article/hidden-dangers-of-...

The anesthesia is scary - my grandpa-in-law was never the same after he had surgery. He went in totally lucid and came out of surgury totally out of it with dementia-like symptoms. It was permanent and it made him have to go into a home. He didn't even know who I was anymore. The surgery itself was routine and very uneventful but the difference in mental function pre and post op were as dramatic as night and day - and permanent.

I mentioned it to my doctor in casual conversation and she says she has seen that happen before when older people have surgery, especially those in not so great health. The article says "researchers hit on two other factors that increased the chances a patient would become dramatically confused after an operation: being older than about 70." He was about 80.

I wonder if he had a stroke while under anesthesia - but maybe they would have seen that?

The same thing happened to my grandmother. She went in for a minor hernia operation, and came out a different person. She never recovered. It was very dramatic and very sad.

Same thing happened to my grandfather as well -- late 70s, was put under to have a small bladder tumor removed, came out of the anesthesia delirious, and was in a nursing home for the rest of his life.

Scary, and terrible.

Wow, thanks for that link about anesthesia! I never thought to look into anesthesia being the culprit of what I'm about to relate..

5 years ago I underwent major surgery after an incident. I remember one day being fine and normal and then my next memories are of me slowly becoming self-aware, conscious & lucid again in a hospital bed over the course of somewhere between 15-30 days (I'm not sure I can pin-point a specific time I became fully aware of where I was and what had happened).

The period of time in between my surgery and when I was fully awake was without a doubt the most terrifying experience of my life. Mentally, I was in a nightmare state for what felt like a large extent of the time that I was 'out of it.' I still have memories and images in my mind today of the dreams I experienced falling in and out of consciousness while slowly 'waking' up over a month.

I have a distant in-law, cousin of my wife, who is a doctor of anesthesiology at a fairly prominent regional hospital...

He often says that he wishes he had gone into another specialty because of the uncertainties inherent in anesthetizing someone even when they're healthy and the most soundly tested protocols are rigidly followed...

He recently underwent a surgery to remove a deep dime-sized BCC (basal cell carcinoma)on his cheek near one eye...though the surgery took nearly 2 hours, primarily to minimize scarring, he adamantly refused everything but local anesthesia...

Elective surgery, with anesthesia, is not something to consider lightly..

What about the stuff they give you for a colonoscopy? Those are highly recommended for adults of a certain age, it would be horrible if the complications from anesthesia outdid the known benefits.

I've had colonoscopy with and without meds. It's not so bad without.

Mind you, when I came round from my bowel resection (which was a 5 hour op) my pain relief wasn't working and I had to wait 6 hours for my doctor - that was a crazy ride - so I think my attitude to pain has changed.

Could it be that Alzheimer's plaque is the ultimate expression of an attempt by the body to deal with CJD?

They mention that they controlled for it.

No, CJD has a clear culprit, the prion protein, that does not appear in "normal" AZ disease.

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