Meaningful Progress in Developing a Blood Test for Alzheimer's Disease

The state of the art for detecting Alzheimer's disease in earlier stages has advanced considerably in the last decade. As noted here, methods are presently good enough to worth using. What should one do if given an early diagnosis of Alzheimer's disease? Based on what is known of the relevant mechanisms, and their plausibility as a direct contribution, an adventurous person might: (a) start taking antiviral drugs, given the possibility that persistent viral infection drives progression of the condition; (b) work to reduce chronic inflammation by all available means, from exercise to senolytics, as inflammation is clearly important in neurodegeneration; (c) clear the worst microglia from the brain, either via senolytics that can cross the blood-brain barrier (e.g. the dasatinib and quercetin combintion) or some form of CSF1R inhibitor. There are probably other reasonable strategies, given a sensible consideration of plausible cost and plausible benefit, even in the absence of clinical proof.

A blood test has proven highly accurate in detecting early signs of Alzheimer's disease in a study involving nearly 500 patients from across three continents, providing further evidence that the test should be considered for routine screening and diagnosis. The blood test assesses whether amyloid plaques have begun accumulating in the brain based on the ratio of the levels of the amyloid beta proteins Aβ42 and Aβ40 in the blood.

Researchers have long pursued a low-cost, easily accessible blood test for Alzheimer's as an alternative to the expensive brain scans and invasive spinal taps now used to assess the presence and progression of the disease within the brain. Evaluating the disease using PET brain scans - still the gold standard - requires an average cost of $5,000 to $8,000 per scan. Another common test, which analyzes levels of amyloid-beta and tau protein in cerebrospinal fluid, costs about $1,000 but requires a spinal tap process that some patients may be unwilling to endure.

This study estimates that prescreening with a $500 blood test could reduce by half both the cost and the time it takes to enroll patients in clinical trials that use PET scans. Screening with blood tests alone could be completed in less than six months and cut costs by tenfold or more, the study finds. Known as Precivity AD, the commercial version of the test is marketed by C2N Diagnostics. The current study shows that the blood test remains highly accurate, even when performed in different labs following different protocols, and in different cohorts across three continents.



The described measures to be taken in case of early detection of AD are basically a good advice in the general case too. Probably with a looming AD the measures could be taken more aggressively.

Posted by: Cuberat at March 2nd, 2022 10:11 AM

Is there a downside to taking antivirals? Has anyone done a test to see how overall mortality is effected?

Posted by: Matt at March 2nd, 2022 2:44 PM

To clarify, I would maybe expect average lifespan to be extended. Given that latent viruses are theorized (known?) to put to a long term stress on our immune system. But maybe antivirals make some damage long term too?

Posted by: Matt at March 2nd, 2022 3:04 PM

I wonder if some of the anti-virals taken by large numbers of the population for severe Covid might end up having a beneficial effect on AD later in their lives.

Posted by: K at March 6th, 2022 3:51 PM
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