Immune Complex‐induced Disseminated Intravascular Coagulation (DIC) An Experimental Study

Disseminated intravascular coagulation (DIC) was induced in rabbits by administration of antibody and antigen. The rabbits were sensitized passively by i.v. injection of antiferritin antiserum and challenged simultaneously by an i.p. inoculation of ferritin. After the challenge, circulating white blood cells, platelets and plasma fibrinogen levels showed an early fall, reaching minimum values at 3, 10 and 6 h, respectively. Fibrin thrombi appeared first at 2 h, reached a maximum at 5-7 h, and had mostly disappeared by 24 h. Formation of fibrin thrombi was frequent in the lung, liver, kidney and spleen. Early morphological changes included neutrophilic infiltration and accumulation of platelets in capillaries. Ferritin-antiferritin complexes were noted among fibrin thrombi or phagocytized by reticuloendothelial cells and neutrophils. The capacity of Kupffer cells to remove circulating immune complexes was saturated transiently; at this time fibrin thrombosis in various organs was most widespread and severe. It seems likely that formation of antigen-antibody complexes in the microcirculation initiates activation of platelets and neutrophils with subsequent release of mediators responsible for triggering DIC. Activation of complement was another possible factor inducing the reaction. In addition, blockade of the reticuloendothelial system promotes the progression of DIC. It is considered that the methods described constitute a useful model for further elucidation of immune complex-induced DIC.