BACKGROUND: Low amyloid β42 (Aβ42) and high total tau and phosphorylated tau (p-tau) concentrations in the cerebrospinal fluid (CSF) are biomarkers of Alzheimer's disease (AD), reflecting brain deposition of amyloid plaques and tangles. Age and apolipoprotein E allele E4 are two strong risk factors for AD, but few data are still available on their effect on CSF markers in normal aging. OBJECTIVE: To study the effect of age on CSF Aβ42, total tau, and p-tau levels in a well-characterized group of cognitively normal subjects. METHODS: CSF Aβ42 levels of 81 subjects (27% female, 53 ± 15.3 years, range: 21-88) were determined with sandwich enzyme-linked immunosorbent assay; of these, total tau and p-tau levels were measured in 61 (75%) and 42 (52%) cases, respectively. A linear regression analysis between age and CSF markers was carried out on the whole sample and separately in apolipoprotein E allele ɛ4 carriers and noncarriers. RESULTS: The median levels of all markers were significantly different between young (<65 years) and old (≥65 years) subjects (Aβ42: P = .03; tau: P = .02; p-tau: P = .002; tau/Aβ42: P = .004; p-tau/Aβ42: P = .03). The association of marker levels with age was confirmed in linear regression models, where a positive relationship with age was observed for total tau (B = 2.3; 95% confidence interval [CI]: 0.89 to 3.7; P = .002), p-tau (B = 0.5; 95% CI: 0.1 to 0.9; P = .02), and tau/Aβ42 ratio (B = 0.006; 95% CI: 0.002 to 0.01; P = .002). No subjects showed abnormal tau, whereas 19% showed abnormal CSF Aβ42 concentrations. CONCLUSION: In cognitively normal subjects, the concentrations of CSF biomarkers of AD are associated with age. Further longitudinal studies could clarify whether Aβ42 low levels represent a preclinical AD biomarker.

Cerebrospinal fluid markers for Alzheimer's disease in a cognitively healthy cohort of young and old adults.

PEDRINI, LAURA;
2012-01-01

Abstract

BACKGROUND: Low amyloid β42 (Aβ42) and high total tau and phosphorylated tau (p-tau) concentrations in the cerebrospinal fluid (CSF) are biomarkers of Alzheimer's disease (AD), reflecting brain deposition of amyloid plaques and tangles. Age and apolipoprotein E allele E4 are two strong risk factors for AD, but few data are still available on their effect on CSF markers in normal aging. OBJECTIVE: To study the effect of age on CSF Aβ42, total tau, and p-tau levels in a well-characterized group of cognitively normal subjects. METHODS: CSF Aβ42 levels of 81 subjects (27% female, 53 ± 15.3 years, range: 21-88) were determined with sandwich enzyme-linked immunosorbent assay; of these, total tau and p-tau levels were measured in 61 (75%) and 42 (52%) cases, respectively. A linear regression analysis between age and CSF markers was carried out on the whole sample and separately in apolipoprotein E allele ɛ4 carriers and noncarriers. RESULTS: The median levels of all markers were significantly different between young (<65 years) and old (≥65 years) subjects (Aβ42: P = .03; tau: P = .02; p-tau: P = .002; tau/Aβ42: P = .004; p-tau/Aβ42: P = .03). The association of marker levels with age was confirmed in linear regression models, where a positive relationship with age was observed for total tau (B = 2.3; 95% confidence interval [CI]: 0.89 to 3.7; P = .002), p-tau (B = 0.5; 95% CI: 0.1 to 0.9; P = .02), and tau/Aβ42 ratio (B = 0.006; 95% CI: 0.002 to 0.01; P = .002). No subjects showed abnormal tau, whereas 19% showed abnormal CSF Aβ42 concentrations. CONCLUSION: In cognitively normal subjects, the concentrations of CSF biomarkers of AD are associated with age. Further longitudinal studies could clarify whether Aβ42 low levels represent a preclinical AD biomarker.
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11368/2789923
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