Diagnostic impact of CSF biomarkers in a local hospital memory clinic.
BACKGROUND
CSF biomarkers amyloid-beta 1-42 (Abeta42), total tau (tau) and tau phosphorylated at threonine 181 (ptau-181) are useful diagnostic markers for Alzheimer's disease (AD). We examined the impact of these biomarkers in the diagnostic process in a non-academic memory clinic.


METHODS
One hundred and nine patients with available CSF were included from the local hospital memory clinic. Initially, patients were clinically diagnosed, and the clinician indicated their confidence in the diagnosis. Next the CSF results were presented, and the clinician re-evaluated his initial diagnosis. The main outcomes were changes in initial diagnosis and diagnostic confidence.


RESULTS
Forty-seven patients were initially diagnosed with AD, 26 were diagnosed with another type of dementia, 18 were diagnosed with mild cognitive impairment, and 18 received a non-dementia diagnosis. All biomarkers distinguished between AD and non-dementia (p < 0.01); tau and ptau-181 also distinguished AD from other types of dementia (p < 0.001). After CSF biomarker levels were revealed, 11 diagnoses changed. In 31% of the diagnoses, the clinician gained confidence, while in 10% confidence decreased.


CONCLUSIONS
We found that knowledge of CSF biomarker profiles changed the diagnosis in 10% of the cases, and confidence in the diagnosis increased for one third of the patients.
Alzheimer Center, Department of Neurology, VU University Medical Center, Amsterdam, The Netherlands. m.kester@vumc.nl
Maartje I
MI
Kester
Leo
L
Boelaarts
Femke H
FH
Bouwman
Raymond L
RL
Vogels
Erwin R
ER
Groot
Evert J
EJ
van Elk
Marinus A
MA
Blankenstein
Wiesje M
WM
van der Flier
Philip
P
Scheltens
D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000134:cerebrospinal fluid* / Q000175:diagnosis; D016229:Amyloid beta-Peptides / Q000134:cerebrospinal fluid*; D000704:Analysis of Variance; D015415:Biomarkers / Q000134:cerebrospinal fluid; D003072:Cognition Disorders / Q000134:cerebrospinal fluid* / Q000175:diagnosis; D003704:Dementia / Q000134:cerebrospinal fluid / Q000145:classification* / Q000175:diagnosis; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010446:Peptide Fragments / Q000134:cerebrospinal fluid*; D010750:Phosphoproteins / Q000134:cerebrospinal fluid; D012680:Sensitivity and Specificity; D018709:Statistics, Nonparametric; D016875:tau Proteins / Q000134:cerebrospinal fluid*
D016229:Amyloid beta-Peptides; D015415:Biomarkers; D010446:Peptide Fragments; D010750:Phosphoproteins; C075222:amyloid beta-protein (1-42); D016875:tau Proteins