[Value of D-dimers in diagnosis of acute pulmonary embolism].
FIBRIN BREAKDOWN PRODUCTS: D-dimers are protein substances resulting from the action of 3 enzymes, thrombin, factor XIII and plasmin, on the fibrinogen molecules. In the case of thrombosis, all these enzymatic reactions are activated, explaining the increase in D-dimer levels induced. The notion of a threshold is only significant for a given test; the 500 micrograms/L threshold is widely used for tests relying on ELISA methods (enzyme-linked immunosorbent assay). FROM A TECHNICAL POINT OF VIEW: The use of D-dimer ELISA in excluding pulmonary embolism is now well established. New quantitative tests with latex, based on a turbidimetric method, also appear interesting in this context. The latter is reliable, rapid, inexpensive, remarkably sensitive (97 to 100%) and widely available.
Performed in the initial stages of diagnosis in an out-patient population with a 20-25% prevalence of the disease, it excludes the diagnosis in around 30% of patients. Decisional analysis models have shown that this method is economically profitable. However, in elderly hospitalised patients, its clinical utility is lesser because of its low specificity in this population. The association of high clinical probability of pulmonary embolism and normal D-dimer leves is rare and has a weaker negative predictive value, even when the ELISA technique is used.
Righini
M
M
Division d'Angiologie et d'Hémostase, Hôpital Universitaire de Genève, 24, rue Micheli-du-Crest, 1211 Genève 14-Suisse.
Bounameaux
H
H
Perrier
A
A
D000208:Acute Disease; D003937:Diagnosis, Differential; D005338:Fibrin Fibrinogen Degradation Products / Q000378:metabolism*; D006801:Humans; D011655:Pulmonary Embolism / Q000097:blood / Q000175:diagnosis*; D012016:Reference Values
D005338:Fibrin Fibrinogen Degradation Products; C036309:fibrin fragment D