¹Pediatric Hematology-Oncolgy, Hannover Medical University, Hannover, Germany

Correspondence: Dr M Sauer, Childrens' Hospital-OE 6780, Hannover Medical University, Carl-Neuberg-Strae 1, 30623 Hannover, Germany. E-mail: sauer.martin@mh-hannover.de

Received 12 April 2005; Accepted 23 May 2005; Published online 4 July 2005.

Abstract

Children and adolescents with homozygous beta-thalassemia can be cured by transplantation of normal stem cells after eradication of the thalassemic hematopoietic system. In an attempt to achieve durable engraftment and to minimize regimen-related toxicity (RRT), we have initiated a fludarabine-based pilot protocol not containing cyclophosphamide. Between 1999 and 2004, five children with beta-thalassemia major were enrolled. Median age at transplantation was 11.5 years (range 4–14 years). Three patients received conditioning with fludarabine (30 mg/m²/day 6), oral busulfan (3.5 mg/kg/day 4), and ATG rabbit Fresenius (10 mg/kg/day 4). Two children received intravenous busulfan instead of oral busulfan at a dose of 2 1.4 mg/kg/day 4 days. All children were transplanted with a fresh bone marrow graft from an HLA-identical sibling. Mean cell doses given were 3.7 10⁸ nucleated cells/kg BW (range 2.4–6.2 10⁸/kg). Overall, 5/5 patients achieved donor engraftment and are alive and well. No GVHD exceeding grade I was observed, and 2/5 children maintained donor chimerism at 100%. One patient maintains mixed hematopoietic donor chimerism being between 94 and 97% nearly 5 years after transplant.