Friday December 13, 2019

Scientists Closing in on Blood Test to Screen People for Possible Signs of Alzheimer’s Disease

A blood test — rather than subjective estimates of thinking skills — could get the right people into studies sooner

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FILE - Dr. Jori Fleisher, neurologist, examines Thomas Doyle, 66, at the Rush University Medical Center in Chicago, July 9, 2019. VOA

Scientists are closing in on a long-sought goal — a blood test to screen people for possible signs of Alzheimer’s disease and other forms of dementia. On Monday at the Alzheimer’s Association International Conference, half a dozen research groups gave new results on various experimental tests, including one that seems 88% accurate at indicating Alzheimer’s risk.

Doctors are hoping for something to use during routine exams, where most dementia symptoms are evaluated, to gauge who needs more extensive testing. Current tools such as brain scans and spinal fluid tests are too expensive or impractical for regular check-ups.

“We need something quicker and dirtier. It doesn’t have to be perfect” to be useful for screening, said Maria Carrillo, the Alzheimer’s Association’s chief science officer.

Dr. Richard Hodes, director of the National Institute on Aging, called the new results “very promising” and said blood tests soon will be used to choose and monitor people for federally funded studies, though it will take a little longer to establish their value in routine medical care.

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“Even though no medical treatment is without risk, getting treatment for high blood pressure could be important to maintain brain health in patients with Alzheimer’s disease,” Claassen said. Pixabay 

“In the past year we’ve seen a dramatic acceleration in progress” on these tests, he said. “This has happened at a pace that is far faster than any of us would have expected.”

It can’t come too soon for patients like Tom Doyle, a 66-year-old former university professor from Chicago who has had two spinal fluid tests since developing memory problems four years ago. First he was told he didn’t have Alzheimer’s, then that he did. He ultimately was diagnosed with different problems — Lewy body dementia with Parkinson’s.

“They probably could have diagnosed me years ago accurately if they had had a blood test,” said Doyle, who represents patients on the Alzheimer’s Association’s board.

88% accuracy overall

About 50 million people worldwide have dementia, and Alzheimer’s is the most common form. There is no cure; current medicines just temporarily ease symptoms. Dozens of hoped-for treatments have failed. Doctors think studies may have enrolled people after too much brain damage had occurred and included too many people with problems other than Alzheimer’s.

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Poor sleep can predict Alzheimer’s Risk in elderly. Pixabay

A blood test — rather than subjective estimates of thinking skills — could get the right people into studies sooner. One of the experimental blood tests measures abnormal versions of the protein that forms the plaques in the brain that are the hallmark of Alzheimer’s. Last year, Japanese researchers published a study of it and on Monday they gave results from validation testing on 201 people with Alzheimer’s, other types of dementia, mild impairment or no symptoms.

The blood test results closely matched those from the top tests used now — three types of brain scans and a mental assessment exam, said Dr. Akinori Nakamura of the National Center for Geriatrics and Gerontology in Obu, Japan. The test correctly identified 92% of people who had Alzheimer’s and correctly ruled out 85% who did not have it, for an overall accuracy of 88%. Shimadzu Corp. has rights to the test and is working to commercialize it, Nakamura said.

Ruling out disorders

Another experimental test looks at neurofilament light, a protein that’s a marker of nerve damage. Abdul Hye of King’s College London gave results of a study comparing blood levels of it in 2,300 people with various neurological conditions — Alzheimer’s, other dementias, Parkinson’s, depression, multiple sclerosis, Lou Gehrig’s disease — plus healthy folks for comparison.

Levels were significantly higher in eight conditions, and only 2% of healthy folks were above a threshold they set for raising concern. The test doesn’t reveal which disorder someone has, but it may help rule one out when symptoms may be psychological or due to other problems.

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Like the Japanese test, it measures the abnormal Alzheimer protein, and the new results will show how well the test reflects what brain scans show on nearly 500 people. Pixabay

Later at the conference, Dr. Randall Bateman of Washington University School of Medicine in St. Louis will give new results on a blood test he helped develop that the university has patented and licensed to C2N Diagnostics, a company he co-founded. Like the Japanese test, it measures the abnormal Alzheimer protein, and the new results will show how well the test reflects what brain scans show on nearly 500 people.

“Everyone’s finding the same thing … the results are remarkably similar across countries, across techniques,” said Bateman, whose work is supported by the U.S. government and the Alzheimer’s Association. He estimates a screening test could be as close as three years away.

ALSO READ: Healthy Lifestyle Can Cut Risk of Developing Alzheimer Even if You Have High Genetic Risk: Study

What good will that do without a cure?

An Associated Press-NORC Center for Public Affairs Research poll last year found that most Americans would want to know if they carried a gene tied to a disease even if it was incurable. “What people want most of all is a diagnosis” if they’re having symptoms, said Jonathan Schott of University College London. “What we don’t like is not knowing what’s going on.” (VOA)

Next Story

Blood Test Can Identify Risk of Night-Time High Blood Pressure in People

Most people experience lower blood pressure at night

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A simple Blood Test administered at the beginning of a sleep study could indicate each patient's cardiovascular risk, said the study. Pixabay

Researchers have found that a simple Blood Test can help identify people with obstructive sleep apnea (OSA) who are at higher risk of cardiovascular problems because of a phenomenon called “reverse dipping” that causes blood pressure to rise rather than lower during sleep.

Most people experience lower blood pressure at night. The new study, published in the European Respiratory Journal suggests a potential cause for reverse dipping that may help patients with sleep apnea get the help they need before cardiovascular disease develops.

“We can now identify those with OSA at the highest risk of cardiovascular problems in order to prevent them from developing additional complications,” said David Gozal from the University of Missouri School of Medicine in the US.

“We can treat those patients more aggressively to ensure they adhere to therapy and use their continuous positive airway pressure device (CPAP) properly,” Gozal said.

The researchers studied 46 patients diagnosed with OSA. They ranged in age from 18 to 70. Fifteen participants were identified to have a rise in blood pressure during sleep, while the remaining 31 participants had blood pressure readings that either remained the same or declined at night.

The researchers collected a blood sample from each participant to study the messages cells produce and send to each other through microscopic packages called exosomes.

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Researchers have found that a simple Blood Test can help identify people with obstructive sleep apnea (OSA) who are at higher risk of cardiovascular problems because of a phenomenon called “reverse dipping” that causes blood pressure to rise rather than lower during sleep. Pixabay

“We found that the cell messages coming from participants with night-time elevated blood pressure were different than those transmitted in subjects with normal blood pressure,” Gozal said.

“The altered messages caused the cells that line the blood vessels to become dysfunctional. Those disturbed vessels allowed inflammatory cells to enter the vessels’ walls, causing hardening of those vessels and leading to cardiovascular disease.”

ALSO READ: Kids Born Through C-Section At Low Obesity Risk

Gozal said the cell message discovery will help clinicians personalise treatment for each patient diagnosed with OSA.

A simple blood test administered at the beginning of a sleep study could indicate each patient’s cardiovascular risk, said the study. (IANS)