Pj. Gaffney et al., FIBRIN DEGRADATION PRODUCT (FNDP) ASSAYS - ANALYSIS OF STANDARDIZATION ISSUES AND TARGET ANTIGENS IN PLASMA, British Journal of Haematology, 90(1), 1995, pp. 187-194
The in vivo formation of fibrin and its subsequent secondary fibrinoly
tic digestion yields a variety of crosslinked fibrin degradation produ
cts (XL/FnDP), One of these is known as D-dimer and a variety of ELISA
-type commercial kits using monoclonal antibodies to D-dimer have been
developed. We have investigated the possibility of establishing a sta
ndard such that these various kits might indicate the same levels of D
-dimer in the same samples. We have concluded that because it seems th
at each individual monoclonal antibody to D-dimer targets a unique and
distinct epitope in the FnDP fraction the notion of introducing a sta
ndard D-dimer which will respond uniformly to each D-dimer monoclonal
antibody is not feasible. Using various monoclonal and polyclonal anti
bodies in conjunction with gel exclusion chromatography we have examin
ed human plasma derived from patients with disseminated intravascular
coagulation (DIC) which contained high levels of fibrin degradation pr
oducts (FnDP). The data suggested that the FnDP fraction in plasma con
tained mostly high molecular weight (>2x10(6) daltons) crosslinked fra
gments which contain high levels of fibrinopeptide A. Many of these cr
osslinked fragments crossreact with antibodies to D-dimer because they
each contain D-dimer as a structural component. On the basis of this
data, a novel sequence of events is proposed which may occur during th
e aggregation of fibrin in vivo.