A circulating anticoagulant inhibiting antihaemophilic globulin

The Immunologic Character of Acquired Inhibitors of Antihemophilic Globulin (Factor VIII) and the Kinetics of Their Interaction with Factor VIII*

“…Inhibitory activity generally has been found in y-globulin-rich fractions isolated by ammonium sulfate precipitation (1, 13), alcohol fractionation (3,8,9), and electrophoresis (1,13,31,32) ; however, one patient has been reported in whom the electrophoretic y-globulin fraction was devoid of activity (10). A sedimentation constant of 7 S has been estimated by density gradient centrifugation in a single case (13), and a similar, or smaller, size can be inferred from the report of transplacental transfer of a circulating anticoagulant (33).…”

“…Most inhibitors are found in individuals belonging to one of four clinical groups: 1) patients with classical hemophilia A (2, 3); 2) normal postpartum females, within the first 6 months after delivery (4, 5); 3) individuals suffering from a wide variety of disease states having, or thought to have, an immunologic setting (e.g., rheumatoid arthritis, penicillin reactions) (6)(7)(8); and 4) elderly persons, of both sexes, in prior good health (9)(10)(11). The nature of these inhibitors has not been clearly defined.…”

Acquired Inhibitors in Nonhemophilic Patients

“…100% residual factor VIII = no inhibitor present.) [87,125,151]. It is not surprising that steroids are not effective since in many cases the inhibitor developed while the patient received steroids for treat ment of the underlying disease [9,31,65,132,137], Immunosuppressive treatment.…”

Le rôle des inhibiteurs faibles du facteur VIII

“…Cependant tous ne sont peut-être pas des y-globulines [24,25]. De plus, des subs tances très différentes telles que l'hématoporphyrine, peuvent se com porter comme des inhibiteurs caractéristiques du facteur VIII [8].…”