J Neuroimmunol. 2002 Nov;132(1-2):164-72.
CD45 isoform
alteration in CD4+ T cells as a potential diagnostic marker of Alzheimer's
disease.
Tan J, Town T, Abdullah L, Wu Y, Placzek A, Small B, Kroeger J, Crawford F, Richards D, Mullan M.
Department of Psychiatry, Roskamp Institute, University of South Florida, 3515
E. Fletcher Ave., Tampa, FL 33613, USA. jtan@hsc.usf.edu
Aging represents the greatest risk for development of Alzheimer's disease (AD),
and changes in peripheral immune cell phenotypes have been found to be
associated with aging. Using flow cytometry, we
measured the relative expression levels of CD45 isoforms,
a marker of nai;ve versus
memory CD4+ T cell status, on isolated CD4+ T lymphocytes from patients with a
clinical diagnosis of probable Alzheimer's disease, normal elderly, cognitively
abnormal elderly, and patients with clinically diagnosed other forms of dementia.
Data show significantly lower levels of CD45RA, and an increase in the
CD45RO/CD45RA ratio, on CD4+ T cells in patients diagnosed with probable
Alzheimer's disease (n=46) and in cognitively abnormal individuals (n=37)
compared to age-matched normal participants (n=90). Patients diagnosed with
other forms of dementia (n=19) did not significantly differ from normal
individuals. Both CD45RA and the CD45RO/CD45RA ratio had higher positive and
negative predictive values and were more sensitive biomarkers of probable AD
than the apolipoprotein E epsilon 4 allele, and had
greater predictive ability for probable AD by regression analyses.
Additionally, a testing strategy employing apolipoprotein
E genotyping and CD45RA or the CD45RO/CD45RA ratio revealed increased
sensitivity, positive and negative predictive values, and predictive ability
over the apolipoprotein E epsilon 4 allele. These
data show altered peripheral immunity in AD patients, and raise the possibility
that a testing strategy using CD45 isoform alteration
on CD4+ T cells and apolipoprotein E genotype may be
clinically valuable for diagnosing probable AD.
Link:
Keywords: CD45, CD4+, Alzheimer's disease, diagnostic marker