23 September 2018

Postulating Alzheimer's as an infectious disease

It's not totally fanciful.  Here are some excerpts from an NPR article:
Norins is quick to cite sources and studies supporting his claim, among them a 2010 study published in the Journal of Neurosurgery showing that neurosurgeons die from Alzheimer's at a nearly 2 1/2 times higher rate than the general population.

Another study from that same year, published in The Journal of the American Geriatric Society, found that people whose spouses have dementia are at a 1.6 times greater risk for the condition themselves.

Contagion does come to mind. And Norins isn't alone in his thinking. In 2016, 32 researchers from universities around the world signed an editorial in the Journal of Alzheimer's Disease calling for "further research on the role of infectious agents in [Alzheimer's] causation." Based on much of the same evidence Norins encountered, the authors concluded that clinical trials with antimicrobial drugs in Alzheimer's are now justified...

Tanzi believes that in many cases of Alzheimer's, microbes are probably the initial seed that sets off a toxic tumble of molecular dominoes. Early in the disease amyloid protein builds up to fight infection, yet too much of the protein begins to impair function of neurons in the brain. The excess amyloid then causes another protein, called tau, to form tangles, which further harm brain cells.

But as Tanzi explains, the ultimate neurological insult in Alzheimer's is the body's reaction to this neurotoxic mess. All the excess protein revs up the immune system, causing inflammation — and it's this inflammation that does the most damage to the Alzheimer's-afflicted brain...

Remember when we thought ulcers were caused by stress?" Ulcers, we now know, are caused by a germ.

6 comments:

  1. in a way, that is scary, but, as with ulcers, good, as maybe then alz's can be stopped by a good dose of 'something'.

    I-)

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  2. "neurosurgeons die from Alzheimer's at a nearly 2 1/2 times higher rate than the general population."

    If that is true, that's a scary pointing finger. :(

    Lurker111

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    1. http://thejns.org/doi/pdf/10.3171/2010.1.JNS091740

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    2. I wouldn't make too much of it. The last line of this paper states, " In general, neurosurgeons benefited from significantly reduced all-cause mortality." This tells me the neurosurgeons lived longer than general population and therefore had more time to develop and die from Alzheimers, as opposed to the rest who went by way of heart disease, stroke, cancer, etc.

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    3. Maybe. It's worth noting that this research was not done to study Alzheimers in neurosurgeons per se - it is a study of cause-specific mortality (i.e. all causes of death). And note in the Methods section they did use SMRs (Standardized Mortality Ratios), which correct for age (and sex) of the person at the time of death. Death rates of course are always 100%, and anything that decreases deaths from one cause will statistically increase deaths from some other cause (don't tell an anti-vaxxer this, but getting Pneumovax will increase a person's risk for dying of a glioblastoma etc).

      I don't know to what extent the SMR would adjust for the average age (85) of the neuro deaths.

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  3. I've been reading that when they do an autopsy on people who died with Alzheimer's they find different types of fungus in the brain, so it's possible that this is a fungal infection, which would fit with the slow progression of the disease. It would be interesting and inexpensive to test anti-fungal drugs and see if A. It clears up the fungal infection and B. Whether the damage is permanent or the patients recover from the dementia.

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