Effect of crosslinking on the structure of solubilized fibrin degradation products in whole plasma.

The purpose of these studies was to establish the validity of 125I fibrin autoradiography--SDS gel techniques for monitoring degradation products from whole plasma or blood clots. These methods can be used to study fibrin degradation not only in patients with congenital factor XIII deficiency, but also in patients with disseminated intravascular coagulation or deep vein thrombosis during the course of thrombolytic therapy. Such an assay might complement existing immunologic techniques to characterize fibrin degradation in vivo by providing an in vitro analysis of the rate and pattern of fibrin degradation in whole blood or plasma. Fibrin degradation was traced by Coomassie blue staining for protein and by autoradiography on SDS-PAGE of degradation products released from a 125I-labeled fibrin tracer. The degradation of non-crosslinked clots from purified fibrin supplemented with plasmin showed a typical release of X, Y, D, and E fibrin fragments. Subsequently, all X and Y fragments were digested to D and E fragments. The degradation of non-crosslinked washed clots prepared from plasma supplemented with plasmin reflected the same pattern. The degradation of non-crosslinked washed clots prepared from EDTA anticoagulated plasma without added plasmin also showed release of X, Y, D, and E fragments. However, in contrast to the non-crosslinked washed clots supplemented with plasmin, there was no additional degradation of the X and Y fragments. These studies established that the pattern of degradation of the 125I-radiolabeled fibrin tracer was similar to that of the total protein released from the fibrin clot as observed by protein staining.(ABSTRACT TRUNCATED AT 250 WORDS)