Wednesday, July 29, 2020

Breakthrough Test for Alzheimer's

New blood test shows great promise in the diagnosis of Alzheimer's disease



Date:

July 29, 2020

Source:

Lund University


Summary:

A new blood test demonstrated remarkable promise in discriminating between persons with and without Alzheimer's disease and in persons at known genetic risk may be able to detect the disease as early as 20 years before the onset of cognitive impairment, according to a large international study.



Brain essentials in plain language. Click here!

    

FULL STORY


A new blood test demonstrated remarkable promise in discriminating between persons with and without Alzheimer's disease and in persons at known genetic risk may be able to detect the disease as early as 20 years before the onset of cognitive impairment, according to a large international study published today in the Journal of the American Medical Association (JAMA) and simultaneously presented at the Alzheimer's Association International Conference.


For many years, the diagnosis of Alzheimer's has been based on the characterization of amyloid plaques and tau tangles in the brain, typically after a person dies. An inexpensive and widely available blood test for the presence of plaques and tangles would have a profound impact on Alzheimer's research and care. According to the new study, measurements of phospho-tau217 (p-tau217), one of the tau proteins found in tangles, could provide a relatively sensitive and accurate indicator of both plaques and tangles -- corresponding to the diagnosis of Alzheimer's -- in living people.


"The p-tau217 blood test has great promise in the diagnosis, early detection, and study of Alzheimer's," said Oskar Hansson, MD, PhD, Professor of Clinical Memory Research at Lund University, Sweden, who leads the Swedish BioFINDER Study and senior author on the study who spearheaded the international collaborative effort. "While more work is needed to optimize the assay and test it in other people before it becomes available in the clinic, the blood test might become especially useful to improve the recognition, diagnosis, and care of people in the primary care setting."




Brain essentials in plain language. Click here!



Researchers evaluated a new p-tau217 blood test in 1,402 cognitively impaired and unimpaired research participants from well-known studies in Arizona, Sweden, and Colombia. The study, which was coordinated from Lund University in Sweden, included 81 Arizona participants in Banner Sun Health Research Institute's Brain Donation program who had clinical assessments and provided blood samples in their last years of life and then had neuropathological assessments after they died; 699 participants in the Swedish BioFINDER Study who had clinical, brain imaging, cerebrospinal fluid (CSF), and blood-based biomarker assessments; and 522 Colombian autosomal dominant Alzheimer's disease (ADAD)-causing mutation carriers and non-carriers from the world's largest ADAD cohort.


In the Arizona (Banner Sun Health Research Institute) Brain Donation Cohort, the plasma p-tau217 assay discriminated between Arizona Brain donors with and without the subsequent neuropathological diagnosis of "intermediate or high likelihood Alzheimer's" (i.e., characterized by plaques, as well as tangles that have at least spread to temporal lobe memory areas or beyond) with 89% accuracy; it distinguished between those with and without a diagnosis of "high likelihood Alzheimer's" with 98% accuracy; and higher ptau217 measurements were correlated with higher brain tangle counts only in those persons who also had amyloid plaques.


In the Swedish BioFINDER Study, the assay discriminated between persons with the clinical diagnoses of Alzheimer's and other neurodegenerative diseases with 96% accuracy, similar to tau PET scans and CSF biomarkers and better than several other blood tests and MRI measurements; and it distinguished between those with and without an abnormal tau PET scan with 93% accuracy.

In the Colombia Cohort, the assay began to distinguish between mutation carriers and non-carriers 20 years before their estimated age at the onset of mild cognitive impairment.


In each of these analyses, p-tau217 (a major component of Alzheimer's disease-related tau tangles) performed better than p-tau181 (another component of tau tangles and a blood test recently found to have promise in the diagnosis of Alzheimer's) and several other studied blood tests.


In the last two years, researchers have made great progress in the development of amyloid blood tests, providing valuable information about one of the two cardinal features of Alzheimer's. While more work is needed before the test is ready for use in the clinic, a p-tau217 blood test has the potential to provide information about both plaques and tangles, corresponding to the diagnosis of Alzheimer's. It has the potential to advance the disease's research and care in other important ways.


"Blood tests like p-tau217 have the potential to revolutionize Alzheimer's research, treatment and prevention trials, and clinical care," said Eric Reiman, MD, Executive Director of Banner Alzheimer's Institute in Phoenix and a senior author on the study.


"While there's more work to do, I anticipate that their impact in both the research and clinical setting will become readily apparent within the next two years."


Alzheimer's is a debilitating and incurable disease that affects an estimated 5.8 million Americans age 65 and older. Without the discovery of successful prevention therapies, the number of U.S. cases is projected to reach nearly 14 million by 2050.




Brain essentials in plain language. Click here!




Thursday, July 23, 2020

Covid-19 and the Brain

July 8, 2020

Source:

University of Liverpool


Summary:

Cases of brain complications linked to COVID-19 are occurring across the globe, a new review has shown. The research found that strokes, delirium and other neurological complications are reported from most countries where there have been large outbreaks of the disease.





    

FULL STORY

Cases of brain complications linked to COVID-19 are occurring across the globe, a new review by University of Liverpool researchers has shown.



Published in The Lancet Neurology, the study found that strokes, delirium and other neurological complications are reported from most countries where there have been large outbreaks of the disease.


COVID-19 has been associated mostly with problems like difficulty breathing, fever and cough. However, as the pandemic has continued, it has become increasingly clear that other problems can occur in patients. These include confusion, stroke, inflammation of the brain, spinal cord, and other kinds of nerve disease.


A recent Liverpool-led study of COVID-19 patients hospitalised in the UK found a range of neurological and psychiatric complications that may be linked to the disease.




To get a sense of the wider picture, the researchers brought together and analysed findings from COVID-19 studies across the globe that reported on neurological complications. The review, which included studies from China, Italy and the USA among others, found almost 1000 patients with COVID-19-associated brain, spinal cord and nerve disease.


Research Fellow, Dr Suzannah Lant, who was working on the project, said: "While these complications are relatively uncommon, the huge numbers of COVID-19 cases globally mean the overall number of patients with neurological problems is likely to be quite large."


One of the complications found to be linked to COVID-19 is encephalitis, which is inflammation and swelling of the brain.


Dr Ava Easton, CEO of the Encephalitis Society, and co-author on the paper said: "It is really important that doctors around the world recognise that COVID-19 can cause encephalitis and other brain problems, which often have potentially devastating, life-changing consequences for patients."


Professor Tom Solomon, senior author on the paper and Director of the Global COVID-Neuro Network, added: "Although such patients are being seen everywhere the virus occurs, many of the reports are lacking in detail. We are currently pooling data from individual patients all around the world, so that we can get a more complete picture. Doctors who would like to contribute patients to this analysis can contact us via the Global COVID-Neuro Network

website."