Clinical Study of a Urinary Competitive ELISA for Neural Thread Protein in Alzheimer Disease

Abstract

AD7C-NTP (neural thread protein) is
a
41-kD brain protein that is selectively
elevated in Alzheimer disease
(AD). AD7C-NTP is associated with the
pathologic changes of AD, and overexpression
of the AD7C-NTP gene is associated
with cell death similar to that
found in the AD brain. A newly developed
competitive ELISA (enzyme-linked
immunosorbent assay) was tested in
urine samples from patients with AD,
patients with non-AD dementia, and
healthy normal individuals. Mean assay
measurement in the AD group (30.1 
10.8) was significantly higher than in
the non-AD dementia control group
(13.4  3.4) and in the nondementia
control group (14.8  5.2) (P  .001).
Mean assay measurement in early-AD
cases (25.3  7.6) was significantly
lower than in other AD cases (33.9 
11.4). Levels of more than 18 units were
found in 89% of overall AD cases and
in 10% of overall controls. The results
further validate urinary AD7C-NTP as a
biochemical marker for AD and indicate
that the competitive ELISA-format AD7CNTP
test in urine is an accurate method
for determining AD7C-NTP levels in
AD.