Longitudinal cerebrospinal fluid tau load increases in mild cognitive impairment.

Publication Type	Academic Article
Authors	de Leon M, Segal S, Tarshish C, DeSanti S, Zinkowski R, Mehta P, Convit A, Caraos C, Rusinek H, Tsui W, Saint Louis L, DeBernardis J, Kerkman D, Qadri F, Gary A, Lesbre P, Wisniewski T, Poirier J, Davies P
Journal	Neurosci Lett
Volume	333
Issue	3
Pagination	183-6
Date Published	11/29/2002
ISSN	0304-3940
Keywords	Amyloid beta-Peptides, Cognition Disorders, tau Proteins
Abstract	Cross-sectional cerebrospinal fluid (CSF) levels of tau and amyloid (A) beta (beta) are of diagnostic importance for Alzheimer's disease (AD) and mild cognitive impairment (MCI). However, most longitudinal studies of tau fail to demonstrate progression. Because predominantly brain-derived proteins such as tau, have higher ventricle to lumbar ratios, we hypothesized that adjusting for the ventricular enlargement of AD would correct for the dilution of tau, and improve detection of longitudinal change. Abeta which is not exclusively brain derived, shows a ratio <1, and no benefit was expected from adjustment. In a 1 year longitudinal study of eight MCI and ten controls, we examined CSF levels of hyperphosphorylated (P) tau231, Abeta40, and Abeta42. In cross-section, MCI patients showed elevated Ptau231 and Abeta40 levels, and greater ventricular volumes. Longitudinally, only after adjusting for the ventricular volume and only for Ptau231, were increases seen in MCI. Further studies are warranted on mechanisms of tau clearance and on using imaging to interpret CSF studies.
DOI	10.1016/s0304-3940(02)01038-8
PubMed ID	12429378