New Alzheimer's marker strongly predicts
mental decline
March 6, 2012--A new marker of Alzheimer's
disease can predict how rapidly a patient's
memory and other mental abilities will
decline after the disorder is diagnosed,
researchers at Washington University School
of Medicine in St. Louis have found.
In 60 patients with early Alzheimer's
disease, higher levels of the marker,
visinin-like protein 1 (VILIP-1), in the
spinal fluid were linked to a more rapid
mental decline in the years that followed.
Scientists need to confirm the results in
larger studies, but the new data suggest
that VILIP-1 potentially may be a better
predictor of Alzheimer's progression than
other markers.
"VILIP-1 appears to be a strong indicator of
ongoing injury to brain cells as a result of
Alzheimer's disease," says lead author Rawan
Tarawneh, MD, now an assistant professor of
neurology at the University of Jordan.
"That could be very useful in predicting the
course of the disease and in evaluating new
treatments in clinical trials."
The study appears March 6 in Neurology.
VILIP-1 was originally identified as a
potential indicator of brain cell damage in
the laboratory of Jack Ladenson, PhD, the
Oree M. Carroll and Lillian B. Ladenson
Professor of Clinical Chemistry in Pathology
and Immunology at Washington University.
Scientists think VILIP-1 serves as a calcium
sensor in brain cells. It is released into
the cerebrospinal fluid when the cells are
injured.
Tarawneh is a former postdoctoral research
associate in the laboratory of David
Holtzman, MD, the Andrew B. and Gretchen P.
Jones Professor and head of Washington
University's Department of Neurology. In an
earlier study, she and her colleagues showed
that healthy subjects with high levels of
VILIP-1 were more likely to develop
cognitive impairment and Alzheimer's disease
over a two- to three-year follow-up period.
For the new study, scientists identified
patients with very mild or mild Alzheimer's
disease enrolled in studies at the Charles
F. and Joanne Knight Alzheimer's Disease
Research Center at Washington University
School of Medicine.
At the outset, researchers measured levels
of VILIP-1 in patients' spinal fluid and
assessed their mental abilities using an
extensive battery of tests. The cognitive
function testing was repeated annually.
"Memory and other mental abilities declined
faster in patients with the highest levels
of VILIP-1," Tarawneh says. "In patients
with early symptoms of Alzheimer's disease,
VILIP-1 seems to be at least as good as —
and potentially even better than — the other
prognostic indicators we used in the study."
The two additional indicators studied were
the proteins amyloid beta and tau. Changes
in the spinal fluid levels of those proteins
mainly reflect the fact that amyloid beta
and tau are starting to form abnormal
deposits in the brain. In contrast, VILIP-1
appears to reveal how much damage to brain
cells has occurred as a result of brain
changes caused by Alzheimer's.
"These results are intriguing, but we need a
larger study to fully understand how the
insights provided by VILIP-1 compare to
those we can gain from other markers,"
Tarawneh says.
She is working with Washington University
scientists to standardize the tests that
measure VILIP-1 for expanded use in
research.