Year: 2008
Type: dissertation
Study design: Observational Study
Abstract: Objective: Longitudinal changes in CSF biomarkers, that are of potential use to study the course of the disease and effects of treatment, have been studied scarcely. We evaluated changes in CSF beta-Amyloid1-42 (Aβ1-42) levels with time and assessed the infl uence of variability of assays and storage of specimen on the results. Methods: 114 patients (54% male, age 67±9 years) with various cognitive and neurological disorders were included. All patients underwent two spinal taps (mean follow-up time 21 months). Aβ1-42 was measured with a sandwich ELISA (Innotest β-Amyloid1-42; Innogenetics, Ghent, Belgium). Baseline samples were assayed twice: once shortly after the fi rst spinal tap and once, in a separately stored aliquot, concomitant with the follow-up sample. Variances of coeffi cients of variation were calculated. Results: Mean Aβ1-42-level at baseline was 485±242 pg/ml. Mean Aβ1-42-level at follow up was 520±249 pg/ml (p=0.00). Repeated mean baseline Aβ1-42-level was 477±232 pg/ ml. Variance of the baseline and follow up CSF-sample pairs run on the same assay was 10% and 18% for pairs run on separate assays. Variance of repeated Aβ1-42 assessment in baseline CSF-samples was 14%. Storage time was found not to be associated with differences in Aβ1-42-level. Conclusion: In case of repeated spinal taps, determination of Aβ1-42-levels should be performed in the same assay. However, the measuring error of repeated Aβ1-42 assessment exceeds the biological changes over time. This may imply, that with the methodological limitations of the present ELISA, repeated Aβ1-42-assessment is not feasible in a clinical setting.
Author: Femke H. Bouwman
Language: English
Subfield: Psychiatry and Mental health
Field: Medicine
Domain: Health Sciences
Open Access status: green
OpenAlex ID: W1502981516