Treatment of acquired amegakaryocytic thrombocytopenic purpura with cyclophosphamide.

A patient with severe amegakaryocytic thrombocytopenic purpura was treated with cyclophosphamide and had an excellent response after four weeks. His condition remained in complete remission for at least five months. Acquired amegakaryocytic thrombocytopenic purpura is a rare disorder with several possible causes. An intrinsic defect at the level of the megakaryocyte colony-forming units, or a circulating autoantibody directed against these colony-forming units has been suggested. This patient's response to cyclophosphamide supports the hypothesis of an immune mechanism in some of these cases, and it is recommended that immunosuppressive therapy be further evaluated.