CSF beta-amyloid 1-42 and tau in Tunisian patients with Alzheimer's disease: the effect of APOE epsilon4 allele.
Alzheimer's disease (AD) is the leading cause of dementia. Currently, no definitive diagnostic test for AD exists. An accurate, convenient and objective test to detect AD is urgently needed for efficient drug development and effective clinical use of emerging therapies. The aim of the present work is to investigate the usefulness of cerebrospinal fluid (CSF) beta-amyloid protein (Abeta1-42) and total tau protein (t-tau) analyses in the diagnosis of AD and whether apolipoprotein E (ApoE) epsilon4 allele is a factor for AD affecting Tunisian people. Abeta1-42 and t-tau levels were measured in CSF from AD patients (n=73), non-Alzheimer dementia (nAD, n=35) and healthy controls (HC, n=38) by sandwich enzyme-linked immunosorbent assay. Abeta1-42 levels were decreased and t-tau increased in AD patients. The combination of Abeta1-42 and t-tau at baseline yielded a sensitivity of 87.4% for detection of AD. The specificities were 97.3% for controls and 82.7% for other dementia. The ApoE epsilon4 allele frequency (29.5%) was significantly higher in the AD patients than in the nAD patients (17.1%) or in the control groups (9.5%). AD patients carrying ApoE epsilon4 allele had lower Abeta1-42 (p<0.001) levels than those without a epsilon4 allele. The combination of t-tau and Abeta1-42 is a robust and reliable assay that may be useful in discriminating cases at risk for AD such as ApoE epsilon4 allele carriers from nAD patients or from age-matched control subjects.
Smach
Mohamed Ali
MA
Department of Biochemistry, Faculty of Medicine of Sousse, Tunisia. dalifms@yahoo.fr
Charfeddine
Bassem
B
Lammouchi
Turkia
T
Harrabi
Imed
I
Ben Othman
Leila
L
Dridi
Hedi
H
Bennamou
Soufien
S
Limem
Khalifa
K
D000368:Aged; D000369:Aged, 80 and over; D000483:Alleles; D000544:Alzheimer Disease / Q000134:cerebrospinal fluid* / Q000175:diagnosis / Q000235:genetics*; D016229:Amyloid beta-Peptides / Q000134:cerebrospinal fluid*; D053327:Apolipoprotein E4 / Q000235:genetics; D001057:Apolipoproteins E / Q000235:genetics; D003704:Dementia / Q000175:diagnosis / Q000235:genetics / Q000378:metabolism; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D005260:Female; D005500:Follow-Up Studies; D005838:Genotype; D006801:Humans; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests / Q000706:statistics & numerical data; D010446:Peptide Fragments / Q000134:cerebrospinal fluid*; D016133:Polymerase Chain Reaction; D011237:Predictive Value of Tests; D012016:Reference Values; D016875:tau Proteins / Q000134:cerebrospinal fluid*
D016229:Amyloid beta-Peptides; D053327:Apolipoprotein E4; D001057:Apolipoproteins E; D010446:Peptide Fragments; C075222:amyloid beta-protein (1-42); D016875:tau Proteins