Seminars in Vascular Medicine 2005; 05(4): 315-320
DOI: 10.1055/s-2005-922476
Copyright © 2005 by Thieme Medical Publishers, Inc., 333 Seventh Avenue, New York, NY 10001, USA.

Validation, Calibration, and Specificity of Quantitative D-Dimer Assays

Carl-Erik Dempfle1
  • 1I Department of Medicine, University Hospital of Mannheim, Mannheim, Germany
Further Information

Publication History

Publication Date:
22 November 2005 (online)

ABSTRACT

Assays for D-dimer antigen are based on monoclonal antibodies reactive with epitopes found on fibrin fragment D-dimer but not on fibrinogen fragment D, other fibrinogen degradation products, or native fibrinogen. The antibodies react with conformational epitopes generated by factor XIII-induced linkage of the C-terminal appendages of the fibrin γ-chains of adjacent D-domains within a fibrin polymer. For some monoclonal antibodies, degradation of the cross-linked fibrin compound by plasmin is an additional requirement for the generation of the epitope. In clinical plasma samples, D-dimer antigen assays detect an array of fibrin compounds of different molecular weights, including fibrin fragment D-dimer as well as higher-molecular-weight fibrin degradation products and fibrin X-oligomers. Most D-dimer antigen represents cross-linked soluble fibrin present in circulation rather than degradation products from particulate clots. Due to differences in epitope reactivity, harmonization of D-dimer antigen assays can only be achieved with standard preparations containing a similar variety of cross-linked fibrin compounds. Assay technologies include manual latex agglutination assays, automated latex-enhanced light-scattering immunoassays, enzyme-linked immunoassays, and others.