1. a dimer byproduct resulting from fibrinolysis; produced by cross linkage of d-domain fibrin monomers by activated factor XIII, fibrin stabilizing factor; present in low levels in normal animals, but found at particularly high levels in association with thrombotic and hemostatic disorders; assayed as an adjunctive diagnostic tool in conditions such as malignant neoplasia, infectious disease, immune-mediated hemolytic anemia, immune-mediated thrombocytopenia, hyperadrenocorticism, pulmonary thromboembolism, and disseminated intravascular coagulation or DIC. d-dimer production requires both plasmin and thrombin activation. Note that generation of fibrin/fibrinogen degradation products (FDPs) requires only plasmin action on fibrin or fibrinogen. d-dimers clear through urinary excretion, so assay may show falsely increased levels during renal dysfunction. Laboratory ELISA measurement can identify fibrinolysis.
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