title: Quantification of unfractionated heparin in human plasma and whole blood by means of novel fluorogenic anti-FXa assays.
abstract: Novel and sensitive plate-based fluorogenic anti-factor Xa (FXa) assays were investigated to quantify unfractionated heparin (UFH) in human plasma and whole blood within the therapeutic ranges of 0-1.6 U/mL and 0-0.8 U/mL, respectively. Two fluorogenic anti-FXa assay methods were defined for low (0-0.6 U/mL) and high (0.6-1.2 U/mL) pharmacologically relevant UFH concentration ranges in pooled human plasma. In both cases significant differences were observed at intervals of 0.2 U/mL (P<0.05). The semi-logarithmic plots of the calibration curves in the low and high UFH range were both fitted to linear regressions with correlation coefficients of 0.96 and >0.99, respectively. The assay was also optimized for whole blood which was capable of differentiating UFH concentrations at intervals of 0.2 U/mL (P<0.05) in the range of 0-0.4 U/mL. The statistically different results were fitted to a linear regression with a correlation coefficient of >0.99. The results obtained in this study could assist diagnostic laboratories towards improved monitoring of UFH therapy.
authors.affiliation: Biomedical Diagnostics Institute, National Centre for Sensor Research, Dublin City University, Dublin 9, Ireland. vanessa.castro.lopez@gmail.com
authors.forename: Vanessa
authors.initials: V
authors.lastname: Castro-López
authors.forename: Leanne F
authors.initials: LF
authors.lastname: Harris
authors.forename: James S
authors.initials: JS
authors.lastname: O'Donnell
authors.forename: Anthony J
authors.initials: AJ
authors.lastname: Killard
mesh_terms: D000328:Adult; D002138:Calibration; D015951:Factor Xa / Q000032:analysis*; D005260:Female; D006493:Heparin / Q000097:blood*; D006801:Humans; D008297:Male; D013056:Spectrophotometry, Ultraviolet
chemical_list: D006493:Heparin; D015951:Factor Xa