Importance of Pre-analytical Stability for CSF Biomarker Testing

Willemse, Eline A.J.; Teunissen, Charlotte E.

doi:10.1007/978-3-319-01225-4_5

Cited by 7 publications

(4 citation statements)

References 65 publications

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“…This does not exclude other pre-analytical factors from influencing the differences in PGRN concentrations reported in previous studies. These pre-analytical factors could relate to patient factors, such as diet or diurnal rhythm, or assay performance, such as differences in buffer compositions or machine settings [24]. Illustratively, the selection of patient groups could account for the discrepancies between studies, as several patient-related factors, such as hypertension, were recently found to influence blood PGRN levels [28].…”

Section: Discussionmentioning

confidence: 99%

“…This discrepancy between concentration ranges could be due to a) bias between methods due to a lack of standardization or harmonization, b) analytical performance (imprecision), and c) variation in preanalytical factors affecting the protein, a well-known issue in biomarker studies in body fluids comprising changes in patient-characteristics (e.g., age, dietary factors, physical exercise) as well as processing and storage of the sample, before the actual analysis has taken place [24]. Sensitivity of PGRN to preanalytical conditions might explain the large variation in serum PGRN levels between studies, however, no studies have addressed the effect of differences in preanalytical handling on PGRN levels in either blood or CSF.…”

Section: Introductionmentioning

confidence: 99%

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Stability of Progranulin Under Pre-Analytical Conditions in Serum and Cerebrospinal Fluid

Willemse

Durieux-Lu

Flier

et al. 2016

JAD

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Abstract. Progranulin (PGRN) levels in blood and cerebrospinal fluid (CSF) are increasingly studied as potential markers for neurodegenerative disorders. We aimed to 1) characterize two commercially available PGRN ELISAs on several assay validation parameters, 2) assess the stability of PGRN in serum and CSF under pre-analytical conditions, and 3) compare stability in the two assays. Intra-and inter-assay variation, inter-lot variation, linearity, lower limit of detection, and kit correlations were assessed for the Adipogen and R&D PGRN ELISA kits. Blood and serum samples were experimentally exposed to ≤9 freeze/thaw cycles, delayed processing for ≤24 h at room temperature and 4• C, and to temperature stability tests for ≤3 weeks at -20• C, 4• C, room temperature, and 37 • C. Both commercial PGRN ELISA kits showed acceptable ranges for intra-and inter-assay variation, where the R&D kit performed more accurate than the Adipogen kit, especially for inter-assay variation (intra-assay serum: 6.7 and 8.3%, respectively; inter-assay serum: 9.2 and 21.0%; intra-assay CSF: 3.6 and 12.0%; inter-assay CSF: 16.0 and 44.5%). Absolute serum PGRN concentrations were 1.9-fold higher in Adipogen than R&D (p < 0.001) and strongly correlated between both kits (ρ = 0.86, p < 0.0001) and CSF PGRN levels were on the borderline of detection in both kits. PGRN was typically stable under all pre-analytical conditions addressed, although two weeks at 37• C resulted in decreased PGRN concentrations in CSF, only when using the Adipogen kit. These results support further examination of PGRN as a potential marker in neurodegenerative diseases, since PGRN is stable in serum and CSF and can be measured using ELISA kits from several providers.

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Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Stability of Progranulin Under Pre-Analytical Conditions in Serum and Cerebrospinal Fluid

Willemse

Durieux-Lu

Flier

et al. 2016

JAD

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“…Although the effect of pre-analytical variables have been likely minimized if the general guidelines for sample handling have been followed ( 31 ), some of the pre-analytical confounding factors should be specifically measured for the biomarker candidate to detect possible effects induced by different pre-analytical issues. Pre-analytical confounding factors include not only patient variables such as diurnal variation and fasting, but also processing factors such as the effect of freeze/thaw cycles and length of storage at different temperatures ( 28 , 32 , 47 ).…”

Section: Elisa Validationmentioning

confidence: 99%

Facilitating the Validation of Novel Protein Biomarkers for Dementia: An Optimal Workflow for the Development of Sandwich Immunoassays

et al. 2015

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Different neurodegenerative disorders, such as Alzheimer’s disease (AD) and frontotemporal dementia (FTD), lead to dementia syndromes. Dementia will pose a huge impact on society and thus it is essential to develop novel tools that are able to detect the earliest, most sensitive, discriminative, and dynamic biomarkers for each of the disorders. To date, the most common assays used in large-scale protein biomarker analysis are enzyme-linked immunosorbent assays (ELISA), such as the sandwich immunoassays, which are sensitive, practical, and easily implemented. However, due to the novelty of many candidate biomarkers identified during proteomics screening, such assays or the antibodies that specifically recognize the desired marker are often not available. The development and optimization of a new ELISA should be carried out with considerable caution since a poor planning can be costly, ineffective, time consuming, and it may lead to a misinterpretation of the findings. Previous guidelines described either the overall biomarker development in more general terms (i.e., the process from biomarker discovery to validation) or the specific steps of performing an ELISA procedure. However, a workflow describing and guiding the main issues in the development of a novel ELISA is missing. Here, we describe a specific and detailed workflow to develop and validate new ELISA for a successful and reliable validation of novel dementia biomarkers. The proposed workflow highlights the main issues in the development of an ELISA and covers several critical aspects, including production, screening, and selection of specific antibodies until optimal fine-tuning of the assay. Although these recommendations are designed to analyze novel biomarkers for dementia in cerebrospinal fluid, they are generally applicable for the development of immunoassays for biomarkers in other human body fluids or tissues. This workflow is designed to maximize the quality of the developed ELISA using a time- and cost-efficient strategy. This will facilitate the validation of the dementia biomarker candidates ultimately allowing accurate diagnostic conclusions.

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“…Cerebrospinal fluid (CSF) biomarkers, amyloid b (Ab 1-42 ), total tau (T-tau), and phosphorylated tau 181 (Ptau), support the diagnosis of Alzheimer's disease (AD) [1]. Unfortunately, susceptibility to preanalytical/analytical variation has hampered clinical implementation [2][3][4][5][6][7][8][9]. The effect of long-term storage on CSF biomarkers is relevant because historical cohorts are needed to establish universal cutoff values.…”

Section: Introductionmentioning

confidence: 99%

Effect of long‐term storage in biobanks on cerebrospinal fluid biomarker Aβ_1‐42, T‐tau, and P‐tau values

Willemse

Uffelen

Flier

et al. 2017

Alz & Dem Diag Ass & Dis Mo

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IntroductionWe 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.MethodsWe selected 148 Alzheimer's disease samples that had inclusion dates equally distributed over the years 2001 to 2013 from our biobank. The concentrations of CSF biomarkers, amyloid β1–42 (Aβ1–42), total tau (T-tau), and phosphorylated tau181 (P-tau), were measured with one enzyme-linked immunosorbent assay lot. Results were compared with historical results obtained at biobank inclusion.ResultsLinear regression analyses showed that the levels of CSF biomarkers, Aβ1–42, T-tau, and P-tau, were not related to storage time at −80°C (β = 0.015, 0.048, and 0.0016 pg/mL per day, not significant). However, the differences between remeasured concentrations of Aβ1–42 and concentrations at biobank inclusion measured for more than 30 assay batches increased with increasing time difference.DiscussionThe levels of CSF biomarkers, Aβ1–42, T-tau, and P-tau, did not significantly change during the maximum period of 12 years of storage at −80°C. Batch variation for Aβ1–42 is a factor that should be controlled for when using historical cohorts.

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Importance of Pre-analytical Stability for CSF Biomarker Testing

Cited by 7 publications

References 65 publications

Stability of Progranulin Under Pre-Analytical Conditions in Serum and Cerebrospinal Fluid

Stability of Progranulin Under Pre-Analytical Conditions in Serum and Cerebrospinal Fluid

Facilitating the Validation of Novel Protein Biomarkers for Dementia: An Optimal Workflow for the Development of Sandwich Immunoassays

Effect of long‐term storage in biobanks on cerebrospinal fluid biomarker Aβ_1‐42, T‐tau, and P‐tau values

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Importance of Pre-analytical Stability for CSF Biomarker Testing

Cited by 7 publications

References 65 publications

Stability of Progranulin Under Pre-Analytical Conditions in Serum and Cerebrospinal Fluid

Stability of Progranulin Under Pre-Analytical Conditions in Serum and Cerebrospinal Fluid

Facilitating the Validation of Novel Protein Biomarkers for Dementia: An Optimal Workflow for the Development of Sandwich Immunoassays

Effect of long‐term storage in biobanks on cerebrospinal fluid biomarker Aβ1‐42, T‐tau, and P‐tau values

Contact Info

Product

Resources

About

Effect of long‐term storage in biobanks on cerebrospinal fluid biomarker Aβ_1‐42, T‐tau, and P‐tau values