Hageman factor-independent fibrinolytic pathway.

Abstract

The lysis of clots formed by the addition of thrombin to dilute whole plasma containing 125I-labelled fibrinogen was examined in kinetic assays which assessed clot size and release of radiolabel into the lysate. Neither platelets, immunoglobulin, nor Hageman factor was essential for clot lysis in this system. Clot lysis was normal in plasma from patients genetically deficient in either C2 or C6 but abnormal in the plasma of two patients with acquired C3 deficiency. Plateletdeficient plasma depleted of C3 by cobra venom factor or adsorbed with zymosan did not sustain clot lysis. These findings indicate the existence of a humoral fibrinolytic pathway in whole human plasma dependent upon C3 but independent of Hageman factor.