Workshop 37 - Immunological Activation of the Kinin-Forming System

Abstract

This chapter discusses details of the workshop focusing on immunological activation of the kinin-forming system. The initiating event in the generation of bradykinin in human plasma is the activation of Hageman factor. This activation may be accomplished by contact of Hageman factor with a variety of biologic materials including collagen, sodium urate or pyrophosphate crystals, and human articular cartilage. Activated Hageman factor not only initiates the clotting sequence but interacts with one or more cofactors termed “Hageman factor cofactor” to initiate fibrinolysis via the conversion of plasminogen to plasmin. Plasmin, in turn, digests active Hageman factor to form prealbumin Hageman factor fragments. Hageman factor fragments were recognized in human serum, in the rabbit, and in the guinea pig. When compared with intact, activated Hageman factor, the prealbumin Hageman factor fragments have approximately four to six times greater capacity to convert prekallikrein to kallikrein but exhibit only l/20th to 1/100th the ability to correct Hageman factor deficiency.