OVERPRODUCTION OF ANTIPLATELET ANTIBODY AGAINST GLYCOPROTEIN IIB AFTER SPLENECTOMY IN A PATIENT WITH EVANS-SYNDROME RESULTING IN ACQUIRED THROMBASTHENIA

We treated a 33-year-old female with Evans syndrome. She received high dose gamma globulin, prednisolone, and azathioprine, and her platelet count transiently increased. After splenectomy, the platelet count ma rkedly increased. However, the bleeding tendency worsened and the blee ding time was prolonged. A platelet defect, characteristic of thrombas thenia, was found. Antigen-captured ELISA and Western blotting reveale d that the patient's serum had an IgG autoantibody against platelet me mbrane glycoprotein IIb and the patient's plasma inhibited normal plat elet aggregation. These findings suggest that overproduction of the an tiplatelet antibody is triggered by platelet recovery due to splenecto my and affects platelet function resulting in acquired thrombasthenia.