Severe hemorrhagic syndrome secondary to active circulating inhibitors of the intrinsic phase of blood coagulation in 3 patients.

: The study of three adults with severe bleeding due to the presence of acquired anticoagulants that inhibit procoagulant action of Factor VIII and to a lesser degree of factors IX and XI, is described. In one case, this phenomenon occurred during the course of a rheumatoid arthritis, in one case coincided with a megaloblastic anemia (pernicious anemia) and the last case did not have any coexisting disease. Corticosteroids were useless, intravenous cyclophosphamide improved one patient and given orally failed in other patient. The circulating inhibitor disappeared in the patient successfully treated with cyclophosphamide and persisted and was the cause of death in the other two patients. In one patient, column fractioning demonstrated that the anticoagulant was an G immunoglobulin, with higher activity at pH 6.5.