Infrared spectroscopy: a new diagnostic tool in Alzheimer disease.
Biological markers play an evolving role in the diagnosis of Alzheimer disease (AD). We compare conventional measurements of cerebrospinal fluid (CSF) tau and beta-amyloid(1-42) proteins to a novel approach - Fourier transformed infrared (FT-IR) spectroscopy - a simple technique derived from chemical and physical sciences that characterizes intramolecular bonds. For automatic diagnostic analysis, we developed an artificial neural network (ANN). We examined 71 patients with a clinical diagnosis of AD and 66 controls. beta-Amyloid(1-42) was decreased (sensitivity 80% and specificity 78%); tau was elevated (sensitivity 76% and specificity 88%) in CSF of AD patients. The combined tau/beta-amyloid(1-42) quotient was able to distinguish healthy from diseased subjects with 99% sensitivity and 86% specificity. The ANN could separate FT-IR spectroscopy data with 88.5% sensitivity and 80% specificity. FT-IR spectroscopy proved to be cost-effective and simple to perform. Diagnostic sensitivity and specificity is in the range of CSF tau and beta-amyloid(1-42) protein analysis. Larger sample numbers for ANN training and validation could increase diagnostic accuracy and thus prove to be a useful screening tool.
Griebe
Martin
M
Department of Neurology, Universitaetsklinikum Mannheim, University of Heidelberg, Theodor-Kutzer-Ufer 1-3, 68135 Mannheim, Germany. griebe@neuro.ma.uni-heidelberg.de
Daffertshofer
Michael
M
Stroick
Mark
M
Syren
Magdalena
M
Ahmad-Nejad
Parviz
P
Neumaier
Michael
M
Backhaus
Juergen
J
Hennerici
Michael G
MG
Fatar
Marc
M
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000175:diagnosis*; D016229:Amyloid beta-Peptides / Q000134:cerebrospinal fluid; D000704:Analysis of Variance; D015415:Biomarkers; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D016571:Neural Networks, Computer; D009483:Neuropsychological Tests; D010446:Peptide Fragments / Q000134:cerebrospinal fluid; D013055:Spectrophotometry, Infrared; D017550:Spectroscopy, Fourier Transform Infrared; D055815:Young Adult; D016875:tau Proteins / Q000134:cerebrospinal fluid
D016229:Amyloid beta-Peptides; D015415:Biomarkers; D010446:Peptide Fragments; C075222:amyloid beta-protein (1-42); D016875:tau Proteins