Grand rounds. Immune globulin in the treatment of autoimmune thrombocytopenic purpura

Abstract

Two patients with autoimmune thrombocytopenic purpura (ATP) who received high-dose intravenous immune globulin before undergoing splenectomy are described, and the pathogenesis, clinical presentation, diagnosis, and treatment of chronic ATP are reviewed. One patient was a 62-year-old white man who was admitted to the hospital with a history of thrombocytopenia and probable steroid-induced diabetes mellitus. The second patient was a 24-year-old black woman who was admitted for recurrent bleeding episodes and splenectomy. In both patients, immune globulin 1.5 g/kg administered over four to six days resulted in marked elevations of platelet counts. ATP is a platelet disorder of unknown etiology. Platelets with surface-bound antiplatelet antibody are destroyed by the reticuloendothelial system. As the platelet count falls below 30,000-50,000/cu mm, the patient may manifest signs of bleeding such as petechiae, purpura, ecchymosis, menorrhagia, epistaxis, and bleeding from other mucosal surfaces. Corticosteroids are the initial treatment of choice. Splenectomy is considered for children with the life-threatening hemorrhage and for patients who do not respond to corticosteroids. Patients who are refractory to steroid therapy and splenectomy may respond to immunosuppressant agents. Approximately, 80% of patients treated with immune globulin have responded with an increase in platelet count, although this increase is sometimes transient. Immune globulin therapy is recommended for emergency treatment of ATP, as preoperative medication before splenectomy, and for young children in order to postpone splenectomy. Despite a good response to treatment, immune globulin therapy should not be considered a cure for ATP.