Acquired Inhibitors of Coagulants

Recurrent Thrombosis in a Young Woman With a Circulating Anticoagulant Directed Against Factors Xi and Xii

“…As pointed out in the introduction, most acquired inhibitors of coagulation are directed against factor VIII, factor IX or thromboplastin. These inhibitors have been characterized as immunoglobulins (2,8). In our case the inhibitor was recovered among the immunoglobulins, but the inhibitor was not characterized immunologically.…”

Analysis of an Autoimmune Antibody (IgM Class) in a Case of Chronic Lymphocytic Leukaemia

“…In autoimmune diseases, two varieties of auto immune anticoagulant activities are usually described [2,3,12,15]. The first type destroys some coagulation factor.…”

Acquired Factor‐IX Inhibitor in a Nonhaemophilic Patient with Autoimmune Disease*

“…Some clotting inhibitors have been showii to be immunoglobulins of the IgG 4 subclass (Bidwell, 1969). Although in the present patient immunoadsorption allowed a fair purification of the inhibitor, it reacted with all four subclass antisera.…”

“…these immunoadsorbcnts and characterized as an IgG-immunoglobulin using specific antisera.The dcvelopmcnt of acquired inhibitors directed against clotting factors VIII or IX is a well-known complication of substitution therapy in both haemophilia A and haemophilia B. The spontaneous occurrence of inhibitors against factor VIII in non-liaemophilic patients is more rare, and is found primarily in systemic lupus erytliematosus, penicillin reactions, after dclivery and in old age (Margolius et al, 1961;Bidwell, 1969). A factor-IX inhibitor in a non-haeniophilic patient was first postdated by Formanik (1957).…”