title: A multiplexed point-of-care assay for C-reactive protein and N-terminal pro-brain natriuretic peptide.
abstract: Several new plasma protein biomarkers have been associated with increased risk of cardiovascular events. It would be of great value if sets of these markers could be measured in a multiplexed format at point-of-care settings. A major challenge is the extremely wide concentration range in which different plasma biomarkers are present. Two promising biomarkers for cardiac risk prediction are C-reactive protein (CRP) and N-terminal pro-brain natriuretic peptide (NTproBNP). The concentrations of these markers can differ by more than six orders of magnitude. Here we present a chip-based multiplexed assay for CRP and NTproBNP. The high-concentration analyte, CRP, is analyzed in a competitive format, whereas the low-concentration analyte, NTproBNP, is analyzed in a sandwich format. This allows concurrent measurement of the two analytes in a single multiplexed assay. The dynamic ranges for the two assays were optimized to match the relevant serum concentration ranges; thus, no dilutions were needed. Both assays exhibit good precision (5-15% in the clinically relevant concentration ranges), and the limit of detection for the NTproBNP assay was 5 ng/L. Patient plasma samples were used for comparison with clinical methods, resulting in coefficients of determination (R(2)) of 0.9762 and 0.9606 for NTproBNP and CRP, respectively.
authors.affiliation: Åmic, Uppsala SE-751 83, Sweden. jonas.r.melin@gmail.com
authors.forename: Jonas
authors.initials: J
authors.lastname: Melin
authors.forename: Gerd
authors.initials: G
authors.lastname: Rundström
authors.forename: Christer
authors.initials: C
authors.lastname: Peterson
authors.forename: Jimmy
authors.initials: J
authors.lastname: Bakker
authors.forename: Brian D
authors.initials: BD
authors.lastname: MacCraith
authors.forename: Mike
authors.initials: M
authors.lastname: Read
authors.forename: Ove
authors.initials: O
authors.lastname: Öhman
authors.forename: Christina
authors.initials: C
authors.lastname: Jönsson
mesh_terms: D015415:Biomarkers / Q000097:blood; D002097:C-Reactive Protein / Q000032:analysis*; D006801:Humans; D020097:Natriuretic Peptide, Brain / Q000097:blood*; D010446:Peptide Fragments / Q000097:blood*; D019095:Point-of-Care Systems; D040081:Protein Array Analysis / Q000379:methods*
chemical_list: D015415:Biomarkers; D010446:Peptide Fragments; C109794:pro-brain natriuretic peptide (1-76); D020097:Natriuretic Peptide, Brain; D002097:C-Reactive Protein