Making therapeutic decisions in adults with aplastic anemia

The management of adults presenting with aplastic anemia (AA) requires careful exclusion of other causes of bone marrow failure. Late-onset inherited forms of AA may present in adulthood with subclinical disease. Recent long-term studies of HLA identical sibling donor BMT show excellent survival for patients under the age of 40 years, but chronic graft-versus-host disease (GVHD) is still a major problem, impacting on quality of life. Recent improvements in outcome after matched unrelated donor BMT may reflect better donor matching and use of reduced intensity conditioning regimens. For patients treated with immunosuppressive therapy (IST), antithymocyte globulin (ATG) and cyclosporin (CSA) remain the standard regimen with excellent overall survival but less impressive failure-free survival due to nonresponse, relapse and later clonal disorders. The benefit of adding granulocyte colony-stimulating factor (G-CSF) to ATG and CSA is unclear and being assessed in a further prospective European study. Patients who are refractory to conventional IST and currently ineligible for BMT represent difficult management problems. For these patients, new approaches to transplantation are being evaluated, such as fludarabine-based conditioning regimens and the potential use of double umbilical cord blood transplants, but there is a need for new immunosuppressive agents. Improved supportive care is likely to be a major factor in improved outcome of all AA patients whether treated with IST or BMT. Robust predictive factors for response to IST are needed to help in decision making at diagnosis and to help justify exploring novel approaches to therapy.