Pre-analytical stability of serum biomarkers for neurological disease: neurofilament-light, glial fibrillary acidic protein and contactin-1.

Objectives: Neurofilament-light (NfL), glial fibrillary acidic protein (GFAP) and contactin-1 (CNTN1) are blood-based biomarkers that could contribute to monitoring and prediction of disease and treatment outcomes in neurological diseases. Pre-analytical sample handling might affect results, which could be disease-dependent. We tested common handling variations in serum of volunteers as well as in a defined group of patients with multiple sclerosis (pwMS).

Effect of long-term storage in biobanks on cerebrospinal fluid biomarker Aβ, T-tau, and P-tau values.

Introduction: We studied the effect of long-term storage at -80°C on cerebrospinal fluid (CSF) biomarker levels. Our approach assumed consistency of mean biomarker levels in a homogenous Alzheimer's disease patient cohort over time.

Methods: We selected 148 Alzheimer's disease samples that had inclusion dates equally distributed over the years 2001 to 2013 from our biobank.

How to handle adsorption of cerebrospinal fluid amyloid β (1-42) in laboratory practice? Identifying problematic handlings and resolving the issue by use of the Aβ/Aβ ratio.

Introduction: We aimed to investigate factors defining amyloid β (1-42) (Aβ) adsorption during preanalytical workup of cerebrospinal fluid (CSF).

Methods: CSF was transferred to new tubes ≤4 times. Variables tested were different polypropylene tube brands, volumes, CSF Aβ concentrations, incubation times, pipettes, vortex intensities, and other CSF proteins, including hyperphosphorylated tau and Interleukin 1 Receptor Accessory Protein (IL-1RAcP).

Standardization of Assay Procedures for Analysis of the CSF Biomarkers Amyloid β((1-42)), Tau, and Phosphorylated Tau in Alzheimer's Disease: Report of an International Workshop.

Large variation in assay performance and outcomes of CSF Aβ1-42, total Tau (Tau), and phosphorylated Tau (pTau) (at amino acid 181) levels is observed between laboratories. The aim of this study was to assess the differences in assay procedures between several experienced international laboratories, as potential sources of error. 14 groups performed the Aβ42, Tau, and pTau assays according to the guidelines of the manufacturer.