Monoclonal antibodies to crosslinked fibrin degradation products (XL-FDP). II. Evaluation in a variety of clinical conditions.

Plasmas from patients with a wide variety of thrombotic and presumed prethrombotic conditions were examined for high molecular weight crosslinked fibrin degradation products (known as X-oligomers) using a two-site enzyme-linked immunospecific assay (ELISA). This assay employed a catcher-tag principle using two monoclonal antibodies (mabs) directed towards different epitopes on the complex X-oligomer fraction. In general, thrombotic events (pulmonary embolism, PE, myocardial infarction, MI, peripheral vascular disease, PVD, and disseminated intravascular coagulation, DIC) were accompanied by elevated levels of X-oligomers in the plasma. During pregnancy the value of X-oligomer assays was demonstrated to be a clear-cut marker for pre-eclampsia. Patients following a variety of forms of surgery present with heterogeneous plasma levels of X-oligomers and this may merely reflect the formation and lysis of the fibrin formed during and after surgery. The possible value of this ELISA procedure in monitoring thrombolytic therapy is discussed with a critical analysis of the data presented herein. While the assay of X-oligomer was demonstrated to be a valuable marker of fibrinolysis in plasma, more extensive data are required in order to assess whether such an assay is of diagnostic value in thrombosis-related conditions.