Immunosuppressive therapy: a potential alternative to bone marrow transplantation as initial therapy for acquired severe aplastic anemia in childhood?

Abstract

Currently bone marrow transplantation (BMT) with an HLA-identical sibling donor is recommended as optimal therapy for children with acquired severe aplastic anemia (SAA). Immunosuppressive therapy (IST) has become a very successful initial therapy for SAA in children lacking a related bone marrow donor. We wished to evaluate whether current IST regimens may be as efficacious as BMT. A retrospective review identified children treated for SAA over a 12-year period. Children with a related donor received a BMT. Children lacking a donor were treated with IST followed by a "rescue" BMT if IST was ineffective. IST consisted of anti-thymocyte globulin and steroid +/- cyclosporine A. Transfusion independence and survival rates were compared between the two groups. Twenty-seven children were identified. Nine received a related BMT; seven of these survive and are transfusion independent (median follow-up 54 months). Sixteen of 18 patients who received IST are transfusion-independent survivors, including three of four patients who received a rescue BMT (median follow-up 33.5 months). Actuarial survival is 75% (95% CI = 45%, 105%) and 92% (95% CI = 78%, 107%) for the BMT and IST groups, respectively (p = 0.15). Severe toxicity was not experienced by any patient as a result of IST. Equivalent rates of transfusion independence and survival were experienced by patients receiving BMT and IST. We propose that a prospective trial be undertaken to evaluate IST as initial therapy in all children with SAA, to be followed by BMT if there is inadequate response.