Aplastic anemia

Author and Disclosure Information


Acquired aplastic anemia is a diverse hematopoietic disorder in which pancytopenia is associated with extremely reduced bone marrow cellularity. Although certain drugs, organic solvents, and viral infections have been found to antedate this disorder,1 an etiologic agent cannot be identified in approximately 50% of patients2. In cases where a toxic agent or infection can be implicated in causing the disease, the exact pathogenesis is unknown.3 Experimental and clinical evidence has been accumulating to show that in some cases of acquired aplastic anemia, a population of lymphocytes is present which can suppress normal hematopoiesis.4–10 Based on these findings, several clinical trials have been initiated using antithymocyte globulin (ATG) as a therapeutic agent. We report the results of a study of bone marrow erythroid colony formation in a patient with idiopathic aplastic anemia before and after ATG therapy.

Case report

A 12-year-old girl with aplastic anemia of 3 weeks’ duration was referred to The Cleveland Clinic Foundation for further evaluation and treatment. Her clinical course is diagrammed in Figure 1. Blood and bone marrow evaluations at admission revealed marked pancytopenia and hypocellular marrow (Table 1). There was no history of exposure to myelotoxic substances, recent infection, or previous hematologic disease. Peripheral blood lymphocytes contained numerous nonspecific chromosome breaks in 80% of metaphases examined (Fig. 2A); however, no other signs of Fanconi’s syndrome were present. Bone marrow transplantation was considered, but no suitable donor was available. Treatment with equine ATG (Upjohn, lot 17, 912 [−5]) was initiated 2 weeks after admission. . . .



Next Article: