Differential diagnosis, pathogenesis and treatment of the thrombocytopenic purpuras

Abstract

1. 1. The differential diagnosis, pathogenesis and treatment of the thrombocytopenic purpuras have been reviewed, particularly with regard to recent literature. 2. 2. Bone marrow aspiration is most useful in differentiating those diseases in which there is mechanical displacement of the megakaryocytes from idiopathic thrombocytopenic purpura. It has not been useful in distinguishing idiopathic thrombocytopenic purpura from toxic, infectious, allergic or splenomegalic purpuras. It has not been found to be of significant value in predicting the results of splenectomy. 3. 3. Considerable progress has been made in our understanding of the pathogenesis and of the hemostatic defect in idiopathic thrombocytopenic purpura. The most recent evidence favors the existence of a platelet agglutinin in many patients with this disorder. In several patients this agglutinin has been found to persist following splenectomy. This may explain the occurrence of congenital thrombocytopenic purpura in the offspring of splenectomized thrombocytopenic mothers. 4. 4. The possibility of platelet iso-agglutination phenomena, similar to those due to iso-immunization for red cells, is discussed. 5. 5. The improvement in capillary fragility and thrombocytopenia by use of ACTH and cortisone is reviewed. 6. 6. The treatment of secondary thrombocytopenic purpura in which megakaryocytes are mechanically displaced must be directed against the primary bone marrow disorder. If this disorder is malignant in nature, some transient beneficial effects may be obtained with the use of transfusions, preferably of platelet-rich blood, and with the use of ACTH and cortisone. 7. 7. The treatment of infectious, toxic or allergic purpuras should be directed toward such therapy as may be available for the infection and toward the removal of the offending chemical or physical toxin and search for and removal of the suspected allergen. Again the use of transfusions and hormonal therapy may be considered. Splenectomy should be considered only if conservative management fails. 8. 8. In splenomegalic thrombocytopenic purpura the primary disease responsible for the splenomegaly will usually be unaffected by splenectomy. However, splenectomy may be considered in this group when thrombocytopenic purpura appears to threaten the life of the patient. 9. 9. The management of idiopathic thrombocytopenic purpura in children should probably be expectant as most children will have a spontaneous remission. 10. 10. In adults the treatment of idiopathic thrombocytopenic purpura should be expectant for at least four months except when such management appears to menace the life of the patient. The results of expectant management may be somewhat improved by the use of transfusions (preferably of platelet-rich blood or of platelets with siliconized apparatus) and by the use of ACTH or cortisone. These hormones, however, probably have their greatest place in the management of hemorrhagic emergencies and in the preoperative preparation of patients for splenectomy. Although normal or increased megakaryocytes are desirable features in the marrow before splenectomy is to be considered, their presence does not guarantee a successful result nor does the occurrence of decreased megakaryocytes forebode an ominous result. The occurrence of eosinophilia of the marrow also improves the prognosis both with regard to spontaneous remission and the effects of splenectomy. However, the correlation between eosinophilia and prognosis leaves much to be desired. Splenectomy results in “cure” of approximately two-thirds of adults with idiopathic thrombocytopenic purpura. When splenectomy fails completely, ACTH, cortisone, androgen, x-ray castration, emergency hysterectomy and transfusions are therapeutic measures to be considered.