Featured Research

from universities, journals, and other organizations

New Test Predicts Whether Mild Cognitive Impairment Will Convert To Alzheimer's Disease

Date:
March 17, 2009
Source:
University of Pennsylvania School of Medicine
Summary:
A test capable of confirming or ruling out Alzheimer's disease has been validated and standardized. By measuring cerebrospinal fluid concentrations of two of the disease's biochemical hallmarks -- amyloid beta42 peptide and tau protein -- the test also predicted whether a person's mild cognitive impairment would convert to Alzheimer's disease over time. The test accurately ruled out Alzheimer's disease in 95.2 percent of the subjects.

A test capable of confirming or ruling out Alzheimer's disease has been validated and standardized by researchers at the University of Pennsylvania School of Medicine. By measuring cerebrospinal fluid (CSF) concentrations of two of the disease's biochemical hallmarks – amyloid beta42 peptide and tau protein – the test also predicted whether a person's mild cognitive impairment would convert to Alzheimer's disease over time.

Researchers were able to detect this devastating disease at the earliest stages, before dementia symptoms appeared and widespread irreversible damage occurred. The findings hold promise in the search for effective pharmaceutical therapies capable of halting the disease.

Honing in on a previously suggested pathological CSF biomarker signature, a team of Penn Medicine researchers, led by Leslie M. Shaw, PhD, Co-Director of the Penn Alzheimer's Disease Neuroimaging Initiative (ADNI) Biomarker Core, found evidence of neuron degeneration – marked by an increase in CSF concentration of tau proteins – and plaque deposition, indicated by a decrease in amyloid beta42 concentration. In addition, people with two copies of the genetic risk factor for Alzheimer's disease, APOE ε4 , had the lowest concentrations of amyloid beta42, compared to those with one or no copies. The study appears in the online edition of the Annals of Neurology.

"With this test, we can reliably detect and track the progression of Alzheimer's disease," said Dr. Shaw. "Validated biomarker tests will improve the focus of Alzheimer's clinical trials, enrolling patients at earlier stages of the disease to find treatments that can at least delay –and perhaps stop– neurodegeneration. In addition, prevention trials can test methods to delay or block mild cognitive impairment from converting to full-blown Alzheimer's."

Further validation studies of this research test system are underway. Additional work is needed to develop additional biomarkers, as well as identify more genetic risk factors that will help distinguish Alzheimer's from other neurodegenerative diseases characterized by cognitive impairments.

"Thanks to the dedicated researchers and volunteers who participated in this and other Alzheimer's disease studies through the Penn Alzheimer's Disease Core Center and at ADNI trial sites around the US and Canada, we have validated a test where a safe, simple lumbar puncture can provide information to confirm suspected Alzheimer's disease and predict the onset of the disease," said John Q. Trojanowski, MD, PhD, Director of the Penn Alzheimer's Disease Core Center. "Using this technique, we will further our understanding of how the disease progresses and what we can do to stop Alzheimer's disease before it starts."

About the Study

Cerebral spinal fluid samples contributed by 410 ADNI volunteers at 56 sites across the U.S. and Canada were included in this study. To independently establish threshold values for these biomarkers, cerebrospinal fluid samples from 52 Penn Memory Center volunteers with normal cognition and 56 people with confirmed Alzheimer's disease based on post-mortem autopsy diagnosis were also measured. The test was based on the multiplexed xMAP microbead immunoassay system, with reagents provided by Innogenetics.

When compared with normal, healthy adults of the same age, a pattern of changes emerged in people with mild cognitive impairment or Alzheimer's disease. In this group, tau concentrations increased, while amyloid beta42 levels decreased as the disease progressed.

The test was 87 percent accurate overall (80 percent or above is considered clinically useful).

In the CSF samples from those with autopsy-confirmed Alzheimer's disease, the amyloid beta42 concentration threshold was most sensitive and detected Alzheimer's disease at a rate of 96.4 percent.

The test accurately ruled out Alzheimer's disease in 95.2 percent of the subjects.

The test positively predicted the conversion from mild cognitive impairment to Alzheimer's disease at a rate of 81.8 percent.

Data used in preparing this article were produced by the Alzheimer's Disease Neuroimaging Initiative (ADNI) Biomarker Core at Penn or obtained from the ADNI database.


Story Source:

The above story is based on materials provided by University of Pennsylvania School of Medicine. Note: Materials may be edited for content and length.


Cite This Page:

University of Pennsylvania School of Medicine. "New Test Predicts Whether Mild Cognitive Impairment Will Convert To Alzheimer's Disease." ScienceDaily. ScienceDaily, 17 March 2009. <www.sciencedaily.com/releases/2009/03/090316133427.htm>.
University of Pennsylvania School of Medicine. (2009, March 17). New Test Predicts Whether Mild Cognitive Impairment Will Convert To Alzheimer's Disease. ScienceDaily. Retrieved August 1, 2014 from www.sciencedaily.com/releases/2009/03/090316133427.htm
University of Pennsylvania School of Medicine. "New Test Predicts Whether Mild Cognitive Impairment Will Convert To Alzheimer's Disease." ScienceDaily. www.sciencedaily.com/releases/2009/03/090316133427.htm (accessed August 1, 2014).

Share This




More Health & Medicine News

Friday, August 1, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

House Republicans Vote to Sue Obama Over Healthcare Law

House Republicans Vote to Sue Obama Over Healthcare Law

Reuters - US Online Video (July 31, 2014) The Republican-led House of Representatives votes to sue President Obama, accusing him of overstepping his executive authority in making changes to the Affordable Care Act. Mana Rabiee reports. Video provided by Reuters
Powered by NewsLook.com
Despite Health Questions, E-Cigs Are Beneficial: Study

Despite Health Questions, E-Cigs Are Beneficial: Study

Newsy (July 31, 2014) Citing 81 previous studies, new research out of London suggests the benefits of smoking e-cigarettes instead of regular ones outweighs the risks. Video provided by Newsy
Powered by NewsLook.com
Dangerous Bacteria Kills One in Florida

Dangerous Bacteria Kills One in Florida

AP (July 31, 2014) Sarasota County, Florida health officials have issued a warning against eating raw oysters and exposing open wounds to coastal and inland waters after a dangerous bacteria killed one person and made another sick. (July 31) Video provided by AP
Powered by NewsLook.com
Health Insurers' Profits Slide

Health Insurers' Profits Slide

Reuters - Business Video Online (July 30, 2014) Obamacare-related costs were said to be behind the profit plunge at Wellpoint and Humana, but Wellpoint sees the new exchanges boosting its earnings for the full year. Fred Katayama reports. Video provided by Reuters
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins