Fibrinogen and fibrin derivatives in serum from normal and sick children.

Fibrinogen and fibrin derivatives (FD) in serum from 20 normal children and 24 patients with elevated serum levels of FD were characterized using an immunoabsorption method followed by SDS-polyacrylamide gel electrophoresis. In FD from normal children fragments with similar mobilities to fragments Y, D and E were dominant, and also small amounts of D-dimer were present. All five patients with disseminated intravascular coagulation (DIC) showed markedly increased levels of fragments X, Y, D, E and D-dimer, which suggests the coordination of primary and secondary fibrinolysis. In patients with diseases other than DIC, plasmin digests of cross-linked fibrin as well as those of fibrinogen were detected. Our results indicate that high levels of serum FD were commonly associated with combined thrombin, plasmin and factor XIII activities.