[Reference guide for the treatment of aplastic anemia]

Aplastic anemia is a syndrome characterized by the decrease in hematopoietic stem cells along with bone marrow hypoplasia and pancytopenia, which is likely to be a T cell-mediated autoimmune disease. Since the response rate to immunosuppressive therapy is higher if started ahead of time, early initiation of treatment is recommended even in non-severe cases. Among treatment approaches in severe cases, immunosuppressive therapy with anti-thymocyte globulin (ATG) plus cyclosporin is the basic approach. However, the effectiveness of thrombopoietin receptor agonists has also been reported, with recovery of hematopoiesis in three blood lineages observed in some patients. Despite no evidence of increased incidence of genetic mutations with thrombopoietin receptor agonist treatment, bone marrow testing is recommended after three to six months of long-term treatment to detect the presence of chromosomal abnormalities. With regard to hematopoietic stem cell transplantation for aplastic anemia, cyclophosphamide is reduced as a pretreatment therapy, and instead, fludarabine is used in combination in order to reduce cardiotoxicity. Since HLA haploidentical hematopoietic stem cell transplantation has been developed and is being reportedly used in patients with no suitable donors, this transplantation approach might also be extended to aplastic anemia patients who were not considered eligible for transplantation in the past.