Acquired aplastic anemia in children: incidence, prognosis and treatment options

Acquired aplastic anemia is a rare disease. The incidence ranges from two to six new cases per 1 million inhabitants per annum. Bone marrow transplantation (BMT) in case of available human leucocyte antigen (HLA)-identical sibling and immunosuppressive therapy are the main therapeutic modalities currently used in pediatric patients. In large cooperative studies carried out in Europe, overall survival was not significantly different in children with aplastic anemia treated with allogeneic BMT from an HLA-identical sibling (85%) and those treated with immunosuppressive therapy (83%). Survival was significantly worse for patients treated with BMT from an alternative source (26%; p < 0.00001) versus immunosuppressive therapy. Based on these results, therapeutic strategies recommended for aplastic anemia are allogeneic BMT as a first-line therapy for children with an HLA-identical sibling, and immunosuppressive therapy in patients without. In children who do not respond, alternative therapies include BMT from unrelated or mismatched family donors and, more recently, the use of hematopoietic growth factors. Therapeutic choice in childhood severe aplastic anemia should also take into account the possible late effects, such as growth failure and other endocrine problems, that are peculiar to pediatric patients, as well as the risk of malignancies occurring mostly when irradiation is given as part of the conditioning regimen before BMT. As aplastic anemia is such a rare disease, improvements in current treatment strategies can only be achieved by joint efforts between treatment centers. Therefore, patients should be referred to experienced centers early in the course of the disease in order to offer the patient the best therapeutic options presently available.