title: Comparability of serum and plasma concentrations of haemostasis activation markers.
abstract: Since serum and plasma D-dimer concentrations correlate very well, we evaluated the comparability of other haemostasis activation markers in plasma and serum. Prothrombin fragment F1+2, fibrin monomer and D-dimer concentrations were measured with commercially available immunoassays in serum and plasma. Serum to plasma ratios were evaluated to determine the direct (prothrombin fragment F1+2) and indirect (fibrin monomer, D-dimer) downstream influence of prothrombinase on the serum to plasma comparability. Prothrombin fragment F1+2 serum and plasma concentrations did not correlate (R2 = 0.09, ns), while an unexpected high degree of correlation was found for fibrin monomer (R2 = 0.66, p < 0.001), and, as expected, a very good correlation was found for D-dimer (R2 = 0.94, p < 0.001). Median serum to plasma ratios decreased from prothrombin fragment F1+2 (16.26) to fibrin monomer (2.24, p < 0.001) and D-dimer (1.00, p < 0.001), following a highly linear relationship (R2 = 0.93) Plasma and serum concentrations of the evaluated markers correlate the better the farther from prothrombinase activity the respective marker is generated. Serum is not suitable for prothrombin fragment F1+2 measurements, whereas fibrin monomer serum concentrations seem of value for research applications. With the used assay, serum seems an appropriate matrix for clinical D-dimer measurements. This would considerably simplify testing strategies. Validation in further clinical trials is needed.
authors.affiliation: Institute for Clinical Chemistry and Hematology, Kantonsspital St. Gallen, Switzerland. wolfgang.korte@gd-ikch.sg.ch
authors.forename: W
authors.initials: W
authors.lastname: Korte
authors.forename: W F
authors.initials: WF
authors.lastname: Riesen
mesh_terms: D001769:Blood / Q000378:metabolism*; D004797:Enzyme-Linked Immunosorbent Assay; D005338:Fibrin Fibrinogen Degradation Products / Q000096:biosynthesis*; D006801:Humans; D010446:Peptide Fragments / Q000097:blood*; D010949:Plasma / Q000737:chemistry*; D011516:Prothrombin
chemical_list: D005338:Fibrin Fibrinogen Degradation Products; D010446:Peptide Fragments; C036309:fibrin fragment D; C011468:fibrinmonomer; C045879:prothrombin fragment 1.2; D011516:Prothrombin