Analysis of cross-linked fibrin and fibrinogen degradation products with SDS-PAGE and immunoblot

SDS-PAGE and immunoblot technique with anti-FDP-D, -FDP-E, -fibrinogen antibody or anti-FDP-DD monoclonal antibody were applied to analyze FDP fragments prepared from cross-linked fibrin and fibrinogen with plasmic digestion in vitro. FDP fragments of DY(260K), DD(187K), X(245K), Y(166K), D(77K, 97K), E1(58K), E2(46K) and E3(40K) were identified from data of molecular weight and reactivity to four antibodies referred to reports of other investigators. Serum FDP fragments from five DIC suspected patients were analyzed by the same methods. In two patients' sera, DD fragment was a main component, and in the other three patients' sera, D fragment was a main fraction. Proportions of high molecular weight fragments of FDP were considerably different in patients' sera. Appearance of D fragment in our cases was considered to be derived from unstable fibrin (fibrin monomer and dimer) rather than from fibrinogen. Molecular weight of DD fragments from patients' sera had heterogeneity (160 approximately 180K), and the values were different from that (187K) prepared from cross-linked fibrin. In conclusion, SDS-PAGE and immunoblot analysis of serum fragments of FDP will be an useful technique to investigate the clinical and pathological condition of DIC.