title: How Accurate is Your Sclerostin Measurement? Comparison Between Three Commercially Available Sclerostin ELISA Kits.
abstract: Sclerostin, bone formation antagonist is in the spotlight as a potential biomarker for diseases presenting with associated bone disorders such as chronic kidney disease (CDK-MBD). Accurate measurement of sclerostin is therefore important. Several immunoassays are available to measure sclerostin in serum and plasma. We compared the performance of three commercial ELISA kits. We measured sclerostin concentrations in serum and EDTA plasma obtained from healthy young (18-26 years) human subjects using kits from Biomedica, TECOmedical and from R&D Systems. The circulating sclerostin concentrations were systematically higher when measured with the Biomedica assay (serum: 35.5 ± 1.1 pmol/L; EDTA: 39.4 ± 2.0 pmol/L; mean ± SD) as compared with TECOmedical (serum: 21.8 ± 0.7 pmol/L; EDTA: 27.2 ± 1.3 pmol/L) and R&D Systems (serum: 7.6 ± 0.3 pmol/L; EDTA: 30.9 ± 1.5 pmol/L). We found a good correlation between the assay for EDTA plasma (r > 0.6; p < 0.001) while in serum, only measurements obtained using TECOmedical and R&D Systems assays correlated significantly (r = 0.78; p < 0.001). There was no correlation between matrices results when using the Biomedica kit (r = 0.20). The variability in values generated from Biomedica, R&D Systems and TECOmedical assays raises questions regarding the accuracy and specificity of the assays. Direct comparison of studies using different kits is not possible and great care should be given to measurement of sclerostin, with traceability of reagents. Standardization with appropriate material is required before different sclerostin assays can be introduced in clinical practice.
authors.affiliation: Bioanalytical Facility, University of East Anglia, Floor 2, Bob Champion Research and Education Building, Norwich Research Park, James Watson Road, Norwich, NR4 7UQ, UK. i.piec@uea.ac.uk.
authors.forename: Isabelle
authors.initials: I
authors.lastname: Piec
authors.affiliation: Bioanalytical Facility, University of East Anglia, Floor 2, Bob Champion Research and Education Building, Norwich Research Park, James Watson Road, Norwich, NR4 7UQ, UK.
authors.forename: Christopher
authors.initials: C
authors.lastname: Washbourne
authors.affiliation: Bioanalytical Facility, University of East Anglia, Floor 2, Bob Champion Research and Education Building, Norwich Research Park, James Watson Road, Norwich, NR4 7UQ, UK.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Tang
authors.affiliation: Bioanalytical Facility, University of East Anglia, Floor 2, Bob Champion Research and Education Building, Norwich Research Park, James Watson Road, Norwich, NR4 7UQ, UK.
authors.forename: Emily
authors.initials: E
authors.lastname: Fisher
authors.affiliation: Women Ground Close Combat Review, Directorate of Manning (Army), Blenheim Bld, IDL 27, Monxton Road, Andover, SP11 8HT, UK.
authors.forename: Julie
authors.initials: J
authors.lastname: Greeves
authors.affiliation: Women Ground Close Combat Review, Directorate of Manning (Army), Blenheim Bld, IDL 27, Monxton Road, Andover, SP11 8HT, UK.
authors.forename: Sarah
authors.initials: S
authors.lastname: Jackson
authors.affiliation: Bioanalytical Facility, University of East Anglia, Floor 2, Bob Champion Research and Education Building, Norwich Research Park, James Watson Road, Norwich, NR4 7UQ, UK.|Norfolk and Norwich University Hospital, Norwich, NR4 7UV, UK.
authors.forename: William D
authors.initials: WD
authors.lastname: Fraser
mesh_terms: D048868:Adaptor Proteins, Signal Transducing; D000293:Adolescent; D000328:Adult; D015415:Biomarkers / Q000097:blood*; D019485:Bone Morphogenetic Proteins / Q000097:blood*; D004797:Enzyme-Linked Immunosorbent Assay / Q000592:standards*; D005819:Genetic Markers; D006801:Humans; D011933:Reagent Kits, Diagnostic / Q000592:standards*; D015203:Reproducibility of Results; D055815:Young Adult
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D015415:Biomarkers; D019485:Bone Morphogenetic Proteins; D005819:Genetic Markers; D011933:Reagent Kits, Diagnostic; C422903:SOST protein, human
keywords: Clinical utility; ELISA; Metabolic bone disease; Sclerostin