title: Immunosuppressive therapies in the management of acquired immune-mediated marrow failures.
abstract: OBJECTIVE
  Immunosuppression is a key treatment strategy for patients suffering from aplastic anemia or related immune-mediated bone marrow failure syndromes. Several attempts have been performed to improve the standard immunosuppression regimen of horse antithymocyte globulin (h-ATG) and cyclosporine A (CyA).
  
  
  RESULTS
  The addition of a third immunosuppression agent to h-ATG + CyA did not result in any improvement. Antilymphocyte agents other than h-ATG have been investigated. A rabbit-ATG preparation, which was known to be more immunosuppressive than h-ATG, resulted in markedly inferior outcome in a large randomized study from the National Institutes of Health. These data seem to be confirmed in additional experiences with rabbit-ATG from other groups. Cyclophosphamide and alemtuzumab have been proven to be biologically active in small studies, but available data suggest inferior outcomes when compared with h-ATG. All these alternative agents result in a more pronounced lymphocyte depletion, suggesting that the actual mechanisms of action of immunosuppressive therapy in aplastic anemia are not fully understood.
  
  
  CONCLUSIONS
  Immunosuppression by h-ATG and CyA remains the standard of care for aplastic anemia patients lacking a low-risk transplant procedure, resulting in a 60-70% response rate. Rabbit-ATG, cyclophosphamide and alemtuzumab demonstrated a biological activity, but resulted in inferior outcome as compared with h-ATG; thus, they are not recommended as front-line therapy of aplastic anemia.
authors.affiliation: Department of Biochemistry and Medical Biotechnologies, Federico II University of Naples, Naples, Italy. amrisita@unina.it
authors.forename: Antonio M
authors.initials: AM
authors.lastname: Risitano
mesh_terms: D000741:Anemia, Aplastic / Q000188:drug therapy*; D000818:Animals; D000961:Antilymphocyte Serum / Q000627:therapeutic use*; D001855:Bone Marrow Diseases; D000080983:Bone Marrow Failure Disorders; D016572:Cyclosporine / Q000627:therapeutic use; D006457:Hemoglobinuria, Paroxysmal / Q000188:drug therapy*; D006736:Horses; D006801:Humans; D007165:Immunosuppression Therapy / Q000379:methods*; D007166:Immunosuppressive Agents / Q000627:therapeutic use*; D011817:Rabbits
chemical_list: D000961:Antilymphocyte Serum; D007166:Immunosuppressive Agents; D016572:Cyclosporine