FDPs represent fragments D and E, major breakdown products of fibrinogen and fibrin. FDPs do not distinguish between fibrinolysis, fibrinogenolysis (the effect of pathologic or therapeutic fibrinolysis), or the combined effect of fibrinolysis plus thrombin generation, as seen in DIC.
Normal range: <10 Ž ¼g/mL.
Use
FDP, as performed in most laboratories, is a simple and rapid semiquantitative, latex-based test.
It is used, in conjunction with other assays, to diagnose activated fibrinolysis or DIC in suspected patients.
Interpretation
Causes of increased results:
Pathologic and therapeutic fibrinolysis
DIC
Venous thromboembolism and pulmonary embolism
Myocardial infarction
Following trauma and surgery
Disseminated cancer
Complications of pregnancy
Small increase with exercise, severe liver disease
Limitations
Because of its rather limited sensitivity, FDP may not be elevated in single, discrete clots, as seen in isolated deep vein thrombosis or in pulmonary embolism. In such situations, a sensitive d-dimer assay is recommended.
The assay itself, if performed on serum obtained from firmly clotted blood (the designated test tubes contain a potent coagulant venom). If blood is drawn on tubes containing anticoagulant, the assay is invalid (newer tests that use plasma have been developed).
In the presence of rheumatoid factor, the results may be falsely elevated.