Comparison of methods for detecting soluble fibrin in plasma. An in vitro study.
The ability of the COA-SET Fibrin monomer (COA-SET FM) test to detect soluble fibrin was evaluated by comparing the results of the COA-SET FM test with fibrinopeptide A (FPA) determinations following thrombin incubation of plasma or whole blood. In addition, two semiquantitative tests (erythrocytes-agglutination test (FM-test) and ethanol gelation test (EGT] were included in the study. Under the experimental conditions used, the COA-SET FM test proved less sensitive than the FPA-assay. There was a strong correlation between the results obtained by the two tests (r = 0.86, p = 0.0001). When solely regarding low levels of soluble fibrin, however, the correlation was weaker (r = 0.59, p = 0.0003). The FM-test was less sensitive than the COA-SET FM test, but more sensitive than EGT at normal and low fibrinogen concentrations. At high fibrinogen concentrations, however, EGT proved more sensitive than the FM-test. Knowing that 1-2 moles of FPA are released per mole of fibrin monomers formed, a discrepancy was observed between the FPA concentrations and the fibrin monomer concentrations as determined by the COA-SET FM test, the FPA levels being 2-25 times higher than the fibrin monomer levels. The discrepancy was greatest at incipient fibrinogen-fibrin transformation and at high plasma fibrinogen levels. This may suggest that fibrinogen in some way interfered with the stimulating effect of fibrin on the t-PA catalyzed activation of plasminogen, the principle upon which the COA-SET FM test is based.(ABSTRACT TRUNCATED AT 250 WORDS)
Halvorsen
S
S
Haematological Research Laboratory, Ullevål Hospital, University of Oslo, Norway.
Skjønsberg
O H
OH
Ruyter
R
R
Godal
H C
HC
D000431:Ethanol; D005189:False Positive Reactions; D005337:Fibrin / Q000032:analysis*; D005338:Fibrin Fibrinogen Degradation Products / Q000032:analysis; D005344:Fibrinopeptide A / Q000032:analysis; D006386:Hemagglutination Tests; D006801:Humans; D011237:Predictive Value of Tests; D011933:Reagent Kits, Diagnostic; D012995:Solubility
D005338:Fibrin Fibrinogen Degradation Products; D011933:Reagent Kits, Diagnostic; C011468:fibrinmonomer; D005344:Fibrinopeptide A; D000431:Ethanol; D005337:Fibrin