University School of Medicine and collaborators at the
of
getting closer to uncovering an in inexpensive and very convenient test for
Alzheimer’s disease.
This type of test has been studied for several years; however
reliability of results and an inability to replicate the same results have
prevented such a test from being discovered.
Now, scientists
have finally found a group of markers that hold up in statistical analyses in
three independent groups of patients.
Basically, they measured
the levels of 190 proteins in the blood of 600 participants. The subjects
studied included healthy volunteers and individuals that had been diagnosed
with Alzheimer’s disease or mild cognitive impairment (MCI).
“A subset of the 190
protein levels (17) were significantly different in people with MCI or
Alzheimer’s. When those markers were checked against data from 566 people
participating in the multicenter Alzheimer’s Disease Neuroimaging Initiative,
only four markers remained: apolipoprotein E, B-type natriuretic peptide,
C-reactive protein and pancreatic polypeptide.”
Coincidentally, they
discovered a correlation among patients that showed changes in their levels of
these four proteins and their measurements of proteins [beta-amyloid] levels in
their cerebrospinal fluid, a protein previously connected with Alzheimer’s
disease. These correlations allowed
researchers to group together people with MCI that may be at high risk of
developing Alzheimer’s.
“We were looking for a
sensitive signal,” says Hu. “MCI has been hypothesized to be an early
phase of AD, and sensitive markers that capture the physiological changes in
both MCI and AD would be most helpful clinically.”
“The specificity of
this panel still needs to be determined, since only a small number of patients
with non-AD dementias were included,” Hu says. “In addition, the
differing proportions of patients with MCI in each group make it more difficult
to identify MCI- or AD-specific changes.”
Unfortunately, researchers
have not yet been able to uncover a simple blood test to detect Alzheimer’s
disease; however they have discovered ways to ensure that any future tests will
be reliable.
Therefore, neurologists
will have to continue to diagnose Alzheimer’s disease based mainly from an
analysis of clinical symptoms or at times expensive PET brain imaging or
painful spinal tap.
Blood Test for Alzheimer’s Gaining Ground
Alzheimer’s, Amyloid, Apolipoprotein E, B-type Natriuretic Peptide, C-reactive Protein, Cerebrospinal Fluid, Cognitive Impairment, Mild Cognitive Impairment (MCI), Pancreatic Polypeptide, PET Scan, Spinal Tap
