Assessment of CSF levels of tau protein in mildly demented patients with Alzheimer's disease

Abstract

CSF levels of tau protein are increased in many patients with Alzheimer's disease (AD). Studies disagree on whether the increase is found in moderate or severe AD to a greater extent than in mild AD, and in two reports there was an inverse correlation between tau levels and cognitive scores. To readdress this question, we measured CSF tau in a group of mildly impaired patients with AD (Mini-Mental State Examination [MMSE] scores > or =20/30) and compared their tau levels with those in age-comparable normal and neurologic controls. We found that the mean level of CSF tau was significantly increased in the AD group compared with the controls, and 29 of 36 patients with AD had levels that exceeded a cutoff determined in a previous study. CSF tau levels did not correlate with MMSE scores. These findings and those of previous studies show that elevated CSF tau levels are found in most patients with AD, occur early in the course of dementia, and may be useful in supporting the diagnosis of AD.

Value of CSF β-amyloid1–42 and tau as predictors of Alzheimer's disease in patients with mild cognitive impairment

“…Evidence shows that these pathological changes are detectable before the onset of clinical dementia. 2 As clinically mildly demented AD patients show elevated tau protein levels 3,4 and decreased Ab 1-42 levels [5][6][7] in cerebro-spinal fluid (CSF) compared to controls, CSF tau and Ab have been proposed as putative early diagnostic markers in MCI subjects. Patients who converted from MCI to AD showed significantly higher tau levels at baseline compared to healthy individuals.…”

Biomarkers for Evaluation of Clinical Efficacy of Multipotential Neuroprotective Drugs for Alzheimer's and Parkinson's Diseases

“…42,43 The reduction in CSF A␤ in AD has been hypothesized to reflect a deposition of the peptide in senile plaques, with lower levels diffusing to the CSF. Thus, according to Galasko et al, 47 decrease in A␤(1-42) in AD is probably the most consistent BM finding. A␤ alone showed a sensitivity of 78%, and a specificity of 81%, in distinguishing AD patients from elderly controls.…”

Precision Medicine

“…The American Journal of Pathology -ajp.amjpathol.orgappear to be Ab 42 and pathological forms of tau. 27 We quantified Ab 42 and paired helical filament (PHF)-tau in the cerebral cortex from 325 consecutive Adult Changes in Thought participants and observed a generally positive, but complex, relationship.…”

“…27 We quantified Ab 42 and paired helical filament (PHF)-tau in the cerebral cortex from 325 consecutive Adult Changes in Thought participants and observed a generally positive, but complex, relationship. 28 Given the comprehensiveness of brain autopsy, herein, we reanalyzed these published data 28 to test whether isolating AD from common comorbid conditions might bring greater clarity to the quantitative relationship between cerebral cortical Ab 42 and PHF-tauamong individuals without dementia who were last evaluated within 2 years of death ( Figure 4).…”