How to interpret D-dimer fi nding correctly

Abstract

The aim is to point to the preanalytical, analytical and postanalytical characteristics and limitations of D-dimer determination while tending to the rational use of laboratory test and correct interpretation of the fi ndings and literature citations. Low level of D-dimer can be found in good health condition, whereas pathologically elevated D-dimer level is recorded in clinical conditions associated with increased coagulation and fi brinolytic activities or altered D-dimer metabolism. Routine determination of D-dimer is used for diagnosing and treatment monitoring of disseminated intravascular coagulation, and in diff erential diagnosis of thromboembolic conditions. Due to the high negative predictive value, D-dimer concentration lower than the cutoff value excludes the diagnosis of thromboembolic diseases and helps in screening patients that need additional work-up using expensive imaging methods. Immunoassays for quantitative determination of D-dimer concentration are not standardized. Monoclonal anti-D-dimer antibodies of diff erent specifi cities and diff erent detection reactions have been used, resulting in heterogeneity of fi ndings and precluding comparison of diff erent assays. Therefore, for accurate, reliable report and interpretation of results it is necessary to fulfi ll preanalytical requirements such as time of blood sampling, correct performance of the method for determination of D-dimer concentration, and awareness of the limitations of D-dimer determination in particular pathologic conditions. Key words: D-dimer; disseminated intravascular coagulation; fi brinolysis; fi brin fi brinogen degradation products; venous thrombosis