A comparison between ALG and bone marrow transplantation in treatment of severe aplastic anemia.

One hundred patients with severe aplastic anemia were treated and evaluated in a prospective study at our hospital between January 1976 and October 1983. 28 patients had a HLA-identical sibling donor and were treated with bone marrow transplantation. 72 patients without a HLA-identical sibling donor were given antilymphocyte globulin followed by oral low dose androgen therapy. One and a half years to nine years after treatment 13 patients (46%) survive in the transplant group and 53 patients (74%) survive in the second group. All except one in the second group have self-sustaining hematopoiesis without need for transfusions. There is one major difference between the two therapies. Marrow transplantation restores bone marrow function completely and no late hematological complications have been seen in this group. The majority of patients treated with antilymphocyte globulin in contrast have residual abnormalities of hemopoiesis: macrocytosis, mild granulocytopenia and mild thrombocytopenia. Relapse (11 of 72 patients) and clonal hematological disorders, such as paroxysmal nocturnal hemoglobinuria (4 patients) and leukemia (one patient) can occur years after complete bone marrow reconstitution with antilymphocyte globulin. These late disorders are of concern. In spite of this we conclude that antilymphocyte globulin treatment is an effective therapy with low early mortality and morbidity and a high chance for a long sustained remission. Results are better or at least equivalent to bone marrow transplantation and patients with donors should be given the option of transplantation or antilymphocyte globulin.