Pre-Analytical Parameters Affecting Vascular Endothelial Growth Factor Measurement in Plasma: Identifying Confounders

Vascular endothelial growth factor-A (VEGF-A) is intensively investigated in various medical fields. However, comparing VEGF-A measurements is difficult because sample acquisition and pre-analytic procedures differ between studies. We therefore investigated which variables act as confounders of VEGF...

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Published inPloS one Vol. 11; no. 1; p. e0145375
Main Authors Walz, Johanna M, Boehringer, Daniel, Deissler, Heidrun L, Faerber, Lothar, Goepfert, Jens C, Heiduschka, Peter, Kleeberger, Susannah M, Klettner, Alexa, Krohne, Tim U, Schneiderhan-Marra, Nicole, Ziemssen, Focke, Stahl, Andreas
Format Journal Article
LanguageEnglish
Published United States Public Library of Science 2016
Public Library of Science (PLoS)
Subjects
Adult
Age
Angiogenesis
Anticoagulants
Asthma
Blood platelets
Blood Specimen Collection - instrumentation
Blood Specimen Collection - methods
Butterflies
Centrifugation
Centrifuges
Chemistry Techniques, Analytical - methods
Cytokines
Diabetes
Diabetic retinopathy
Enzyme-Linked Immunosorbent Assay
Ethylenediaminetetraacetic acids
Female
Gender aspects
Humans
Impact analysis
Laboratories
Linear Models
Macular degeneration
Male
Measurement methods
Medical materials
Multiplexing
Neonates
Order parameters
Parameter identification
Pharmacology
Plasma
Reagent Kits, Diagnostic - standards
Regression analysis
Regression models
Reproducibility of Results
Sex
Sex differences
Sex Factors
Statistical analysis
Statistical methods
Studies
Toxicology
Tubes
Vascular endothelial growth factor
Vascular Endothelial Growth Factor A - blood
Young Adult
United Kingdom > UK
England
Germany
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Summary:Vascular endothelial growth factor-A (VEGF-A) is intensively investigated in various medical fields. However, comparing VEGF-A measurements is difficult because sample acquisition and pre-analytic procedures differ between studies. We therefore investigated which variables act as confounders of VEGF-A measurements. Following a standardized protocol, blood was taken at three clinical sites from six healthy participants (one male and one female participant at each center) twice one week apart. The following pre-analytical parameters were varied in order to analyze their impact on VEGF-A measurements: analyzing center, anticoagulant (EDTA vs. PECT / CTAD), cannula (butterfly vs. neonatal), type of centrifuge (swing-out vs. fixed-angle), time before and after centrifugation, filling level (completely filled vs. half-filled tubes) and analyzing method (ELISA vs. multiplex bead array). Additionally, intrapersonal variations over time and sex differences were explored. Statistical analysis was performed using a linear regression model. The following parameters were identified as statistically significant independent confounders of VEGF-A measurements: analyzing center, anticoagulant, centrifuge, analyzing method and sex of the proband. The following parameters were no significant confounders in our data set: intrapersonal variation over one week, cannula, time before and after centrifugation and filling level of collection tubes. VEGF-A measurement results can be affected significantly by the identified pre-analytical parameters. We recommend the use of CTAD anticoagulant, a standardized type of centrifuge and one central laboratory using the same analyzing method for all samples.
Bibliography:Conceived and designed the experiments: HD PH AK TK FZ AS. Performed the experiments: JW HD PH AK TK JCG SMK NS-M FZ AS. Analyzed the data: DB HD PH AK TK NS-M FZ AS. Contributed reagents/materials/analysis tools: DB HD PH AK TK NS-M FZ AS. Wrote the paper: JW DB HD LF PH AK TK NS-M FZ AS.
Competing Interests: This study was supported through a research grant from Novartis, Germany. J. M. Walz is a part time employee at Novartis; H. Deissler has received consultancy honoraria and research support from Novartis and travel grants from Bayer HealthCare and Novartis; L. Faerber is an employee at Novartis; P. Heiduschka has received research support from Novartis, Bayer HealthCare and Affiris; A. Klettner has received consultancy honoraria, speaker fees and research support from Novartis; T. U. Krohne has received consultancy honoraria and speaker fees from Bayer HealthCare, Heidelberg Engineering and Novartis, research grants from Alcon and Novartis and travel grants from Bayer HealthCare, Heidelberg Engineering and Novartis; F. Ziemssen has received consultancy honoraria from Alimera, Allergan, Bayer HealthCare and Novartis, speaker fees from Alcon, Alimera, Allergan, Bayer HealthCare, Heidelberg Engineering and Novartis and research support from Allergan and Novartis; A. Stahl has received research support from Novartis and speaker honoraria or consultancy honoraria from Boehringer Ingelheim, Novartis and Zeiss; D. Boehringer, J. C. Goepfert, S. M. Kleeberger and N. Schneiderhan-Marra have no conflict of interest. There are no patents, products in development or marketed products to declare. This does not alter the authors’ adherence to PLOS ONE policies on sharing data and materials, as detailed online in the guide for authors.
ISSN:1932-6203
1932-6203
DOI:10.1371/journal.pone.0145375