Blood take a look at might detect Alzheimer's illness harm

A simple blood test could predict if a patient will develop Alzheimer's disease up to 16 years before symptoms begin, a new study finds. They later detected the bacteria in the animals' brains, along with dying neurons and higher than normal levels of β-amyloid protein.

These findings, published online January 24 in the journal Science, indicate that lack of sleep alone helps drive the disease, and suggests that good sleep habits may help preserve brain health.

Researchers at Cortexyme, a San Francisco pharmaceutical company, are looking into a potential drug to block the gum bacteria's apparent effects in the brain.

It's possible that news of the possible link will lead to people spending more time on their dental health than they now do, though: One study found less than one third of Americans floss daily.

Senior author Professor Dr David Holtzman said: "We've known that sleep problems and Alzheimer's are associated in part via a different Alzheimer's protein - amyloid beta - but this study shows that sleep disruption causes the damaging protein tau to increase rapidly and to spread over time". According to the authors, the bacteria were found in the brains of deceased patients who had been diagnosed with Alzheimer's. Gingipains were also shown to cause damage to Tau, another brain protein thought to be involved in the development of Alzheimer's.

Neuroscience Research Australia (NeuRA), part of the Dominantly Inherited Alzheimer Network (DIAN), collaborated on a publication in Nature Medicine that details evidence for the blood test.

The researchers say: "The findings of this study offer evidence that P. gingivalis and gingipains in the brain play a central role in the [disease development] of [Alzheimer's disease]".

This is not the first time that the bacteria have been linked to Alzheimer's but in their study, the researchers further investigated how it plays a role in the development of the disease. What the team discovered was reported January 24 in the journal Science, in an article titled, "The sleep-wake cycle regulates brain interstitial fluid tau in mice and CSF tau in humans".

The causes of Alzheimer's disease are still debated.

Biotech start-up Cortexyme, Inc., who sponsored the new research, has previously shown a similar drug to be safe and tolerable in both healthy old people and those with Alzheimer's in a Phase 1 clinical trial.

Dr Stephen Dominy, one of the study authors and co-founder of the United States company Cortexyme, which developed COR388, said: "Infectious agents have been implicated in the development and progression of Alzheimer's disease before, but the evidence of causation hasn't been convincing". However if wakefulness increases tau can accumulate faster than it gets cleared away, elevated levels, which are a hallmark of Alzheimer's disease, can form toxic clumps and spread throughout the brain accelerating neurodegeneration.

The Buffalo researchers believe their work in the developing science of epigenetics will yield answers in the elusive search for new Alzheimer's therapies.

In 2019, Cortexyme said, it plans to conduct more trials of COR388 in over 500 people with mild to moderate Alzheimer's disease.

Many of us will know someone living with dementia, or their families and friends who are having to cope with what can be quite distressing situations of seeing their loved ones affected in this way.

  • Delores Daniels