Degradation of fibrinogen and fibrin by plasmin and nonplasmin proteases in the chronic subdural hematoma: evaluation by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblot.

To characterize local hyperfibrinolysis in the pathogenesis of chronic subdural hematoma (CSDH), fibrin degradation products (FDPs) were separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) to identify each FDP fragment (fragments HMW, YY, DY and DD) by immunoblotting. The electrophoretic patterns of FDP in 40 hematomas from 33 patients could be categorized into 3 patterns; (i) type 1, the sharp DY and DD bands; (ii) type 2, the broad DY and DD bands; and (iii) type 3, the sharp DY and DD with two bands with higher molecular weights than fragment DY and DD. The broadening of DY and DD bands was reproduced by incubating the sample containing sharp DD and DY bands with the hemolyzed peripheral blood cells. These results indicated that the hyperfibrinolysis in CSDH could be characterized by the constant and incomplete proteolysis of fibrinogen and fibrin by plasmin and further degradation of FDPs by non-plasmin proteases released from hemolyzed blood cells.