The Laboratory Diagnosis of Venous Thromboembolic Disease by Measurement of Fibrinogen/Fibrin Degradation Products and Fibrin Monomer

¹ Assistant Clinical Professor of Medicine, harvard medical School
² Professor of Surgery, Tufts University School of Medicine
³ Vascular Laboratory, Lemuel Shattuck Hospital; Departments of Medicine, Surgery and Radiology, Tufts University School of Medicine, Boston

The utility of two blood tests for screening patients with suspected venous thromboembolic disease was evaluated. Eighty-two patients who underwent venography and 38 patients who were investigated with radioisotope lung scans or pulmonary angiograms were included. At the time of their radiographic study, their blood was tested for fibringogen/fibrin degradation products and fibrin monomer by the staphylococcal clumping test (SCT) and the serial dilution protamine sulfate (SDPS) test. Patients in whom the diagnosis of pulmonary embolism or symptomatic deep vein thrombosis was confirmed had a significantly higher incidence as well as more strongly positive blood tests compared to the remaining patients. The SCT was more sensitive but the SDPS test was found to be more specific. The study indicates that these tests are sufficiently practical and precise to be used to help resolve the differential diagnosis in suspected venous thromboenbolism. When both tests were negative, significant thromboembolic disease was not found. Evidence is presented suggesting that the coagulation products measured represent the result and not the cause of the thrombosis.