Early Alzheimer’s Detection up to 17 Years in Advance

A sensor identifies misfolded protein biomarkers in the blood. This offers a chance to detect Alzheimer’s disease before any symptoms occur. Researchers intend to bring it to market maturity. The dementia disorder Alzheimer’s disease has a symptom-free course of 15 to 20 years before the first clinical symptoms emerge. Using an immuno-infrared sensor developed in Bochum (Germany), a research team is able to identify signs of Alzheimer’s disease in the blood up to 17 years before the first clinical symptoms appear. The sensor detects the misfolding of the protein biomarker amyloid-beta. As the disease progresses, this misfolding causes characteristic deposits in the brain, so-called plaques.

Our goal is to determine the risk of developing Alzheimer’s dementia at a later stage with a simple blood test even before the toxic plaques can form in the brain, in order to ensure that a therapy can be initiated in time,” says Professor Klaus Gerwert, founding director of the Centre for Protein Diagnostics (PRODI) at Ruhr-Universität Bochum (RUB). His team cooperated for the study with a group at the German Cancer Research Centre in Heidelberg (DKFZ) headed by Professor Hermann Brenner.

The team published the results obtained with the immuno-infrared sensor in the journal “Alzheimer’s & Dementia: The Journal of the Alzheimer’s Association” on 19 July 2022. This study is supported by a comparative study published in the same journal on 2 March 2022, in which the researchers used complementary single-molecule array (SIMOA) technology.

The researchers analysed blood plasma from participants in the ESTHER study conducted in Saarland for potential Alzheimer’s biomarkers. The blood samples had been taken between 2000 and 2002 and then frozen. At that time, the test participants were between 50 and 75 years old and hadn’t yet been diagnosed with Alzheimer’s disease. For the current study, 68 participants were selected who had been diagnosed with Alzheimer’s disease during the 17-year follow-up and compared with 240 control subjects without such a diagnosis. The team headed by Klaus Gerwert and Hermann Brenner aimed to find out whether signs of Alzheimer’s disease could already be found in the blood samples at the beginning of the study.

The immuno-infrared sensor was able to identify the 68 test subjects who later developed Alzheimer’s disease with a high degree of test accuracy (0,78 AUC, Area under Curve). For comparison, the researchers examined other biomarkers with the complementary, highly sensitive SIMOA technology – specifically the P-tau181 biomarker, which is currently being proposed as a promising biomarker candidate in various studies.

Blood Test Spots Signs of Alzheimer’s Years Before Symptoms Appear

“Unlike in the clinical phase, however, this marker is not suitable for the early symptom-free phase of Alzheimer’s disease,
” as Klaus Gerwert summarises the results of the comparative study. “Surprisingly, we found that the concentration of glial fibre protein (GFAP) can indicate the disease up to 17 years before the clinical phase, even though it does so much less precisely than the immuno-infrared sensor.” Still, by combining amyloid-beta misfolding and GFAP concentration, the researchers were able to further increase the accuracy of the test in the symptom-free stage to 0,83 AUC.

The Bochum researchers hope that an early diagnosis based on the amyloid-beta misfolding could help to apply Alzheimer’s drugs at such an early stage that they have a significantly better effect – for example, the drug Aduhelm, which was recently approved in the USA. “We plan to use the misfolding test to establish a screening method for older people and determine their risk of developing Alzheimer’s dementia,” says Klaus Gerwert. “The vision of our newly founded start-up betaSENSE is that the disease can be stopped in a symptom-free stage before irreversible damage occurs.” Even though the sensor is still in the development phase, the invention has already been patented worldwide. BetaSENSE aims to bring the immuno-infrared sensor to market and have it approved as a diagnostic device so that it can be used in clinical labs.

Source: https://news.rub.de/

Rare genetic mutation holds clues to preventing Alzheimer’s

Could one woman’s rare genetic mutation one day have a global impact on dementia risk? It’s possible, say investigators who report on a potentially groundbreaking case of a woman whose genetic mutation staved off dementia for decades, even though her brain had already been damaged by Alzheimer’s disease. While most Alzheimer’s cases are not driven by genetic predisposition, one woman in Colombia is among about 1,200 in her country who do face a genetically higher risk for early-onset Alzheimer’s. Why? They all carry the E280A mutation of a gene called Presenilin 1 (PSEN1), which is known to increase the chances for Alzheimer’s at a far younger age than usual.

We identified an individual that was predisposed to develop Alzheimer’s in her 40s,” noted study author Dr. Joseph Arboleda-Velasquez. He’s an assistant professor of ophthalmology with the Schepens Eye Research Institute of Mass Eye and Ear at Harvard Medical School, in Boston.

But, strangely, the woman “remained unimpaired until her 70s,” Arboleda-Velasquez added. The twist: the woman had, in fact, developed clear telltale signs of Alzheimer’s in her brain. She just hadn’t developed dementia. For example, while she had fewer neural “tangles” in her brain than is typical for Alzheimer’s patients, by the time she hit her 40s she did have the same unusually high level of brain amyloid-beta deposits as her E280A peers. Such deposits are a key signature of Alzheimer’s. So why didn’t she develop middle-aged dementia like her peers?

To unravel the mystery, Arboleda-Velasquez and his colleagues ran an in-depth genetic analysis on the woman. And what they found is that she had not just one mutation, but two. In addition to the E280A mutation, she also carried the so-calledChristchurchmutation in the APOE3 gene. But there’s more. Not only did she carry the Christchurch mutation, but she had two of them. Some of her E280A peers (about 6%) also carried a single copy of Christchurch. But she was the only one who carried two, the investigators found. “It is ultra-rare, with an approximate prevalence of less than one in every 200,000 individuals,” Arboleda-Velasquez said.

And having one such rare mutation did not appear to be enough. No protection against dementia was linked to only one Christchurch mutation. But as this woman’s case suggests, having two such mutations did seem to throw up a shield against Alzheimer’s, preserving her ability to remember things and think clearly for a few decades, long after her E280A peers had started experiencing cognitive decline.

Source: https://www.cbsnews.com/

Eye Test Reveals How Likely Is A Person To Develop Alzheimer’s

Alzheimer’s disease (AD) begins to alter and damage the brain years — even decadesbefore symptoms appear, making early identification of AD risk paramount to slowing its progression.

In a new study published online in the September 9, 2019 issue of the Neurobiology of Aging , scientists at University of California San Diego School of Medicine say that, with further developments, measuring how quickly a person’s pupil dilates while they are taking cognitive tests may be a low-cost, low-invasive method to aid in screening individuals at increased genetic risk for AD before cognitive decline begins.

In recent years, researchers investigating the pathology of AD have primarily directed their attention at two causative or contributory factors: the accumulation of protein plaques in the brain called amyloid-beta and tangles of a protein called tau. Both have been linked to damaging and killing neurons, resulting in progressive cognitive dysfunction.

The new study focuses on pupillary responses which are driven by the locus coeruleus (LC), a cluster of neurons in the brainstem involved in regulating arousal and also modulating cognitive function. Tau is the earliest occurring known biomarker for AD; it first appears in the LC; and it is more strongly associated with cognition than amyloid-beta. The study was led by first author William S. Kremen, PhD, and senior author Carol E. Franz, PhD, both professors of psychiatry and co-directors of the Center for Behavior Genetics of Aging at UC San Diego School of Medicine.

The LC drives pupillary response — the changing diameter of the eyes’ pupils — during cognitive tasks. (Pupils get bigger the more difficult the brain task.) In previously published work, the researchers had reported that adults with mild cognitive impairment, often a precursor to AD, displayed greater pupil dilation and cognitive effort than cognitively normal individuals, even if both groups produced equivalent results. Critically, in the latest paper, the scientists link pupillary dilation responses with identified AD risk genes.

face of an elderly man

How quickly a person’s pupils dilate while doing mental tasks may be an indicator of increased genetic risk for Alzheimer’s disease.

Given the evidence linking pupillary responses, LC and tau and the association between pupillary response and AD polygenic risk scores (an aggregate accounting of factors to determine an individual’s inherited AD risk), these results are proof-of-concept that measuring pupillary response during cognitive tasks could be another screening tool to detect Alzheimer’s before symptom appear,” said Kremen.

Source: https://health.ucsd.edu/

New Hope To Fight Alzheimer’s

It is known that the onset of Alzheimer’s disease (AD) is associated with the accumulation of Amyloid beta () peptides in small molecular clusters known as oligomers. These trigger the formation of so-called ‘neurofibrillary tangles’ within neurons hamper their workings, ultimately causing cell death and so significant cognitive decline. Very large Aβ oligomers which form plaques outside neurons, alongside neuroinflammation have also been found to play a key part in the progression of the disease.

The EU-funded iRhom2 in AD project took as its starting point the protein iRhom2, which has been identified as a genetic risk factor for AD due to its pro-inflammatory properties. The team were able to explore further the influence of iRhom2 on neuroinflammation in mice. iRhom2 recently emerged as a protein of note in AD as it aids the maturation of an enzyme called TACE (tumor necrosis factor-α converting enzyme) guiding it towards a cell’s plasma membrane where the enzyme releases a cell-signalling cytokine (TNFα), implicated in the regulation of inflammatory processes. While mice studies have shown that TNFα-dependent inflammation can lead to sepsis and rheumatoid arthritis, it is also thought that the process contributes to neuroinflammatory signalling events, which can cause harm in the brain.

The EU-funded iRhom2 in AD project worked with mice that are prone to develop the hallmarks of AD, amyloid plaques and memory deficits. The team genetically altered iRhom2 in the mice then analysed the progression of the pathology using an array of biochemical and histological methods, together with a number of behavioural tests to assess cognitive decline. The results were somewhat surprising.

We initially hypothesised that iRhom2 would affect one specific aspect of neuroinflammation in AD. What we discovered was even more exciting as it actually affects several different aspects of neuroinflammation simultaneously. So modulating iRhom2 appears particularly well suited to interfere with AD,” explains project coordinator Prof. Dr. Stefan Lichtenthaler.

Source: https://cordis.europa.eu/