Amyloid beta(1-42) and phosphorylated tau in CSF as markers for early-onset Alzheimer disease.
OBJECTIVE
To determine the diagnostic value of CSF amyloid beta(1-42) (Abeta42), CSF total tau, and CSF tau phosphorylated at threonine-181 (Ptau-181) in early-onset Alzheimer disease (EAD) vs frontotemporal lobar degeneration (FTLD).


METHODS
Levels of Abeta42, total tau, and Ptau-181 in CSF were measured using commercially available ELISA in 47 EAD patients, 28 FTLD patients, and 21 nondemented control subjects.


RESULTS
CSF Abeta42 was significantly lower and CSF total tau and CSF Ptau-181 significantly higher in EAD patients than FTLD patients and control subjects. There was an increase in diagnostic accuracy for CSF Ptau-181 vs CSF total tau (p = 0.067). Combining low CSF Abeta42 and high CSF Ptau-181 allowed EAD patients to be distinguished from FTLD patients with a sensitivity of 72% and a specificity of 93%. Logistic regression analysis with CSF Abeta42 and CSF Ptau-181 as independent continuous variables resulted in correct classification of 46 of 47 (98%) EAD patients and 23 of 28 (82%) FTLD patients. The diagnostic accuracy for EAD was independent of gender, disease duration, and disease severity.


CONCLUSIONS
The combination of CSF Abeta42 and CSF Ptau-181 may help in differentiating EAD from FTLD.
Schoonenboom
N S M
NS
Alzheimer Center, Department of Neurology, VU University Medical Center, Amsterdam, The Netherlands. niki.schoonenboom@vumc.nl
Pijnenburg
Y A L
YA
Mulder
C
C
Rosso
S M
SM
Van Elk
E-J
EJ
Van Kamp
G J
GJ
Van Swieten
J C
JC
Scheltens
Ph
P
D000368:Aged; D000544:Alzheimer Disease / Q000134:cerebrospinal fluid* / Q000175:diagnosis; D016229:Amyloid beta-Peptides / Q000134:cerebrospinal fluid*; D001057:Apolipoproteins E / Q000134:cerebrospinal fluid; D015415:Biomarkers / Q000134:cerebrospinal fluid; D003704:Dementia / Q000134:cerebrospinal fluid* / Q000175:diagnosis; D003937:Diagnosis, Differential; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D016900:Neurofilament Proteins / Q000737:chemistry; D010446:Peptide Fragments / Q000134:cerebrospinal fluid*; D010766:Phosphorylation; D058225:Plaque, Amyloid / Q000737:chemistry; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D012737:Sex Factors; D016875:tau Proteins / Q000134:cerebrospinal fluid*
D016229:Amyloid beta-Peptides; D001057:Apolipoproteins E; D015415:Biomarkers; D016900:Neurofilament Proteins; D010446:Peptide Fragments; C075222:amyloid beta-protein (1-42); D016875:tau Proteins