Cerebrospinal fluid tau and Aβ42 concentrations in healthy subjects: delineation of reference intervals and their limitations
-
Abstract
Many limitations and conflicting results have cast serious doubts on the validity of cerebrospinal fluid tau and Aβ42 levels for the biological diagnosis of Alzheimer's disease, particularly extreme variations of the reference limits found by unrelated groups as a consequence of different reference populations used. In this study, we addressed the issue of defining reference limits for cerebrospinal fluid tau and Aβ42 in healthy adult individuals. One hundred and five neurologically intact subjects were enrolled according to strict inclusion criteria, 10 of them with autopsy confirmation of brain integrity. All cerebrospinal fluid samples were similarly and optimally processed as were the dosage methods used and the statistical analyses performed. A robust correlation with age was demonstrated for Aβ42 but not for tau. For tau, we found that an upper cut-off value of 443 ng/l allowed 95% of the subjects to be correctly classified as normal. For Aβ42, a lower cut-off value of 90 ng/l allowed a correct classification of 90% of the subjects. However, a large variance of the reference values, partly explained by the potential contamination of the reference population with presymptomatic dementia patients, may limit the use of reference limits based on living subjects. We propose that the issue of defining reference limits for both cerebrospinal fluid tau and Aβ42 may ultimately be settled by studying large numbers of autopsy-proven neurologically intact individuals only.
Copyright © 2004 by Walter de Gruyter GmbH & Co. KG
Articles in the same Issue
- How useful are haematology analyser flags?
- Intravenous immunoglobulin (IVIG): modes of action in the clinical management of recurrent pregnancy loss (RPL) and selected autoimmune disorders
- Automated flagging influences the inconsistency and bias of band cell and atypical lymphocyte morphological differentials
- Extracellular concentration of homocysteine in human cell lines is influenced by specific inhibitors of cyst(e)ine transport
- Generation of eight adjacent mutations in a single step using a site-directed mutagenesis kit
- Prohepcidin accumulates in renal insufficiency
- Impurities from polypropylene microcentrifuge tubes as a potential source of interference in simultaneous analysis of multiple lipid-soluble antioxidants by HPLC with electrochemical detection
- Cerebrospinal fluid tau and Aβ42 concentrations in healthy subjects: delineation of reference intervals and their limitations
- The influence of smoking on plasma homocysteine and cysteine levels in passive and active smokers
- Reference change values and power functions
- A different approach to analyzing age-related HbA1c values in non-diabetic subjects
- Ratio of urinary free immunoglobulin light chain κ to λ in the diagnosis of Bence Jones proteinuria
- Influence of blood collection in plastic vs. glass evacuated serum-separator tubes on hormone and tumour marker levels
- Multicenter evaluation of a new immunoassay for procalcitonin measurement on the Kryptor® System
- Comparison of three commercial assays for the measurement of 17α-hydroxyprogesterone (17α-OHPR): limitations of the quality control system
- Analytical performance of the Albumin Cobalt Binding (ACB®) test on the Cobas MIRA® Plus analyzer
- Letter to the Editor
- Meetings and Awards
Articles in the same Issue
- How useful are haematology analyser flags?
- Intravenous immunoglobulin (IVIG): modes of action in the clinical management of recurrent pregnancy loss (RPL) and selected autoimmune disorders
- Automated flagging influences the inconsistency and bias of band cell and atypical lymphocyte morphological differentials
- Extracellular concentration of homocysteine in human cell lines is influenced by specific inhibitors of cyst(e)ine transport
- Generation of eight adjacent mutations in a single step using a site-directed mutagenesis kit
- Prohepcidin accumulates in renal insufficiency
- Impurities from polypropylene microcentrifuge tubes as a potential source of interference in simultaneous analysis of multiple lipid-soluble antioxidants by HPLC with electrochemical detection
- Cerebrospinal fluid tau and Aβ42 concentrations in healthy subjects: delineation of reference intervals and their limitations
- The influence of smoking on plasma homocysteine and cysteine levels in passive and active smokers
- Reference change values and power functions
- A different approach to analyzing age-related HbA1c values in non-diabetic subjects
- Ratio of urinary free immunoglobulin light chain κ to λ in the diagnosis of Bence Jones proteinuria
- Influence of blood collection in plastic vs. glass evacuated serum-separator tubes on hormone and tumour marker levels
- Multicenter evaluation of a new immunoassay for procalcitonin measurement on the Kryptor® System
- Comparison of three commercial assays for the measurement of 17α-hydroxyprogesterone (17α-OHPR): limitations of the quality control system
- Analytical performance of the Albumin Cobalt Binding (ACB®) test on the Cobas MIRA® Plus analyzer
- Letter to the Editor
- Meetings and Awards
