Summary
Various assays have been developed for quantitation of soluble fibrin or fibrin monomer
in clinical plasma samples, since this parameter directly reflects in vivo thrombin
action on fibrinogen. Using plasma samples from healthy blood donors, patients with
cerebral ischemic insult, patients with septicemia, and patients with venous thrombosis,
we compared two immunologic tests using monoclonal antibodies against fibrin-specific
neo-epitopes, and two functional tests based on the cofactor activity of soluble fibrin
complexes in tPA-induced plasminogen activation. Test A (Enzymun®-Test FM) showed the best discriminating power among normal range and pathological
samples. Test B (Fibrinostika® soluble fibrin) clearly separated normal range from pathological samples, but failed
to discriminate among samples from patients with low grade coagulation activation
in septicemia, and massive activation in venous thrombosis. Functional test C (Fibrin
monomer test Behring) displayed good discriminating power between normal and pathological
range samples, and correlated with test A (r = 0.61), whereas assay D (Coa-Set® Fibrin monomer) showed little discriminating power at values below 10 μg/ml and little
correlation with other assays. Standardization of assays will require further characterization
of analytes detected.