Fibrin D-dimer in thrombogenic disorders

Measurement of D-dimer (fibrin degradation product) is important for determining not only the activation of fibrinolysis but also the severity of a hypercoagulable state. However, fibrin degradation products are in variable, and the reactivity to cross-linked fibrin degradation products produced during fibrin degradation differs depending on the kind of antibody used against D-dimer. In patients with disseminated intravascular coagulation or earthquake-induced mental and physical stress and in patients after percutaneous transluminal coronary angioplasty, all of which are associated with acute fibrin formation and degradation, some discrepancies between two methods of D-dimer detection, automated latex agglutination assay (LPIA) and enzyme-linked immunosorbent assay (Stago), were found. No discrepancies in persistent fibrin formation and degradation were found among the healthy elderly, patients with lacunar stroke, and patients with coronary artery disease, almost all of whom had levels under 5.0 mu g/mL, as determined by both methods. Evidence of persistently increased intravascular coagulation and fibrin turnover in patients with atherosclerotic disease was found. The cleavage of crosslinked fibrin by plasmin results in a production of fibrin degradation products, mostly contained D-dimer domains. Although the clinical utility of D-dimer can be achieved by their detection with specific antibodies, measurement of D-dimer as high-molecular-weight fragments may be useful to determine whether patients will undergo further fibrin degradation. When intermediate products of the degradation process need to be assessed, D-dimer level measurement by LPIA may serve as a suitable marker for ongoing fibrinolysis.