1. ¹Division of Clinical Immunology, Karolinska Institutet, Karolinska University Hospital, Huddinge, Stockholm, Sweden
2. ²Center for Allogeneic Stem Cell Transplantation (CAST), Karolinska Institutet, Karolinska University Hospital, Huddinge, Stockholm, Sweden
3. ³Department of Pediatric Dentistry, Karolinska Institutet, Karolinska University Hospital, Huddinge, Stockholm, Sweden
4. ⁴Department of Pediatrics, Karolinska Institutet, Karolinska University Hospital, Huddinge, Stockholm, Sweden
5. ⁵Department of Hematology, Karolinska Institutet, Karolinska University Hospital, Huddinge, Stockholm, Sweden

Correspondence: Dr O Ringdén, Division of Clinical Immunology, Karolinska Institutet, F79, Karolinska University Hospital, Huddinge, SE-141 86 Stockholm, Sweden. E-mail: Olle.Ringden@ki.se

Received 27 October 2006; Revised 9 January 2007; Accepted 10 January 2007; Published online 19 February 2007.

Abstract

Fludarabine-based conditioning (FBC) was given to 24 patients and conventional myeloablative conditioning (MC) to 33 patients, most children, before hematopoietic stem cell transplantation (HSCT) for non-malignant diseases. The donors were human leukocyte antigen (HLA)-A, -B, -DR1-identical related (33%) or unrelated (67%). In the FBC group, two grafts failed versus three in the MC group; all were successfully regrafted. Fever was more common in the MC patients (P=0.003). Bacteremia occurred in 25% of the FBC group and 50% in the MC group (P=0.1). In the FBC group, platelet engraftment was faster and transfusions were fewer (P<0.05). Mucositis and renal function were similar in the two groups. The MC group had higher maximum bilirubin (P=0.03) and less often normal spirometry (P=0.04) after HSCT. A 7-year-old girl in the MC group had permanent alopecia. No patients had severe acute graft-versus-host disease (GVHD). Chronic GVHD was rare. Complete donor CD3+ chimerism was more common in the MC group (P=0.01), but CD33+ engraftment was better with FBS (P=0.03). Treatment-related mortality was 4 and 15%, and 5-year survival was 89 and 85% in the FBC and MC groups. Although survival was similar, FBC is a promising alternative to MC in non-malignant disorders.