Comparison of Immunosorbent Assays for the Quantification of Biomarkers for Alzheimer’s Disease in Human Cerebrospinal Fluid

Abstract

Background: The clinical diagnosis of Alzheimer’s disease in early stages may be substantiated by the quantification of the biomarkers Abeta42, Abeta40 and total-Tau (t-Tau) in cerebrospinal fluid (CSF). Different commercially available immunosorbent assays yield reliable results, yet the absolute values obtained may differ in between tests. Methods: We used CSF samples from patients that reported to our memory clinic. Enzyme-linked immunosorbent assays obtained from Innogenetics were used for the quantification of Abeta42 and t-Tau, test kits from IBL International were used to determine Abeta42 and Abeta40 concentrations. The multiplex assay system obtained from Mesoscale Discovery (MSD) Systems was used for the quantification of all three biomarkers. Results: For all biomarkers, the absolute values obtained with different test systems differ. However, the data sets highly correlate for all comparisons, with the MSD test system proving to be slightly more sensitive. Correlation coefficients (c) for the Abeta42 and Abeta40 quantifications lie between c = 0.80 and c = 0.87, and for the t-Tau quantifications we determined c = 0.99. Conclusion: We conclude that all assays evaluated give reliable results, yet absolute values obtained have to be assessed differently within the framework of diagnostic procedures, depending on the system used.

Biomarkers of dementia: Comparison of electrochemiluminescence results and reference ranges with conventional ELISA

“…This was the case with Innogenetics and MSD tau. Our results confirm those recently published that found a high correlation of t-tau between MSD and Innogenetics in a smaller population of 16 samples [14]. In contrast t-tau values obtained with the microsphere-based Luminex multiplex Eighty six values were below the limit of blank, 55 samples were between the limit of blank and limit of quantification and only 4 samples were above the level of quantification.…”

“…There are large variations in published reference values [4,5,13,14] and it still deems necessary to define laboratory specific reference values. We were able to use well defined normal controls and patient samples of our mono center test population and found similar results for the Innogenetics assays to other published data [7,[15][16][17][18].…”

Neurogranin and BACE1 in CSF as Potential Biomarkers Differentiating Depression with Cognitive Deficits from Early Alzheimer’s Disease: A Pilot Study

“…CSF was collected and analyzed according to strictly standardized protocols described elsewhere [38]. Briefly, this involved collecting 12 mL of CSF in polypropylene tubes.…”

Pre-analytical and analytical factors influencing Alzheimer's disease cerebrospinal fluid biomarker variability

“…Thus, the data could not be used at an individual level for diagnosis. Although the observed biomarker concentrations may vary significantly between platforms, including MSD, xMAP and ELISA, these techniques seem to have similar diagnostic accuracy for patients with AD versus controls [46] or for detecting early AD [47,48].…”