[A patient with hemorrhage originating from an unknown coagulation pathway inhibitor]

The hemorrhagic disorders associated with circulating anticoagulant are rare but well known as the disease derived from inhibitors(alloantibody or autoantibody), which arise against specific coagulation factors. We encountered a patient with hemorrhage at the lower limbs originating from an unknown coagulation pathway inhibitor. Activated partial thromboplastin time(APTT) prolonged and cross mixing test indicated a coagulation pathway inhibitor. Levels of coagulation factors VIII, IX, XI, and XII were extremely low. Predonine therapy was effective to stop the hemorrhage. To clarify the inhibitor, we treated the patient's plasma with protein A Sepharose, and the factor VIII activity was recovered to a normal level after passing through the column. Gel filtration of the patient's plasma and protein A Sepharose adsorbed fraction of the patient's plasma with Superdex 200 revealed that the inhibitor activity against blood coagulation eluted at the position of IgG, which was detected by the prolongation of APTT of normal pooled plasma. These data indicated that the inhibitor was IgG and its inhibitory spectrum was non-specific and broad. The results of laboratory tests and the clinical features in our patient were similar to those in a previous study by Dahlback(Blood 62, 218-225, 1983). The hemorrhagic abnormality of that patient was derived from the autoantibody to phospholipid, which inhibits the activation of prothrombin. An investigation into the effect of anti-phospholipid antibody in our patient is currently being performed in our laboratory.