Origin of Soluble Crosslinked Fibrin Oligomers: An in Vitro Study

In patients with DIC crosslinked high molecular fibrin derivatives (CL-HMD)are observed, which are eluted by gel filtration in the exclusion volume (MW>10⁶ ). Characterization by PAGE revealed that their subunits are similar to crosslinked fdp X. To evaluate their origin, in vitro studies were performed on fibrinolysis products obtained in three ways; (1) by SK-induced fibrinolysis of crosslinked fibrin, (2) by simultaneous action of thrombin and plasmin on Fg in presence of F XIII and Ca⁺⁺, and (3) by limited fibrinogenolysis and subsequent action of thrombin and F XIII upon the resultant early FDP. Reaction (1) resulted in low mol derivatives (LMD) only (D-D, E ), which do not complex with Fg. In contrast, reaction (2) and (3) resulted in HMD and LMD. The former are composed of Cl-‘X’ and complexes of mainly ‘X’ and ‘Y’. In reaction (3) early X precipitates when it is transformed to ‘X’ and to CL-’X’. Late X remains soluble after transition to ‘X’ and CL-’X’. The results suggest, that CL-HMD observed in patients with DIC are not derived from fibrin clots but formed from Fg under combined action of plasmin and thrombin