ABSTRACT
Aplastic anemia is a group of hematologic disorders characterized by peripheral blood pancytopenia and a bypocellular bone marrow. Hematopoietic stem cells are decreased and the residual cells are often functionally defective. A preponderance of evidence suggests that acquired aplastic anemia is inmunologically mediated: activated T-lymphocytes produce increased quantities of gamma interferon and tumor necrosis factor wich result un suppression of hematopoiesis. Choice of initial treatment for apatient with aplastic anemia depends upon a complex interaction between patient age, disease severity and the availability of a bone marrow dono. Patients with mild disease may be treated with observation, androgens, colony stimulating factors or inmunossupression or bone marrow trnasplantation are indicated. As our knowledge of the pathogenesis of aplastic anemia improves, more effective, less taxic treatment should become available.