The Clinical and Laboratory Standards Institute (CLSI) has published 'Quantitative D-dimer for the Exclusion of Venous Thromboembolic Disease; Approved Guideline (H59-A)'
This provides guidance regarding the use of the D-dimer assay for the exclusion of venous thromboembolism (VTE).
Many clinical conditions are associated with increased blood concentrations of D-dimer, some of which include VTE.
H59 assesses the clinical application of the D-dimer assay for the exclusion of VTE for non-hospitalised, ambulatory patients, because many hospitalised patients have elevated D-dimer concentrations for reasons unrelated to VTE, including immobilisation or recent surgery.
This focus aligns with the current application of the D-dimer assay, which is primarily used for the diagnosis and monitoring of disseminated intravascular coagulation and for the exclusion of VTE, in particular, deep vein/venous thrombosis and pulmonary embolism/embolus, which form the core of this document.
The D-dimer assay is a useful tool when evaluating patients with possible VTE, as the absence of D-dimer is helpful in excluding VTE.
The rapid development of commercial assays for D-dimer spurred the development of this document, as significant variability has been reported among these commercial offerings.
A notable discrepancy is found in the types of unit used to report D-dimer concentrations.
H59 addresses this topic, while providing recommendations for harmonisation.
This document focuses on the pre-examination, examination and post-examination (pre-analytical, analytical and post-analytical, respectively) elements of the use of the D-dimer test as it applies to the exclusion of VTE.
It addresses the evaluation of the patient in the determination of the probability of VTE; proper specimen collection, transport and processing; examination (analytical) methods (for example, measurement procedures/analytical methods); reference intervals; establishment and reporting of the threshold for exclusion of VTE; interpretation of results; and aspects of regulatory and accreditation requirements.
It is intended to provide guidance to laboratories, clinicians, manufacturers, and regulators as the use of the D-dimer assay for the exclusion of VTE continues to evolve.
