1. ¹Department of Pediatrics and Adolescent Medicine, Division of Pediatric Hematology and Oncology, University of Freiburg, Germany
2. ²University Children's Hospital, University of Tübingen, Germany
3. ³St Anna Children's Hospital, Wien, Austria
4. ⁴Department of Pediatric Hematology and Oncology, University Hospital Motol, Prague, Czech Republic
5. ⁵University Children's Hospital, University of Frankfurt, Germany
6. ⁶Department of Pediatric Hematology and Oncology, Heinrich-Heine-University, Düsseldorf, Germany
7. ⁷University Children's Hospital, University of Erlangen, Germany
8. ⁸University Children's Hospital, University of Jena, Germany
9. ⁹University Children's Hospital, University of Essen, Germany
10. ¹⁰Department for Pediatric Hematology/Oncology, Kinderklinik Medizinische Hochschule, Hannover, Germany
11. ¹¹Department of Pediatrics and Adolescence Medicine, Division of Pediatric Hematology/Oncology, University of Graz, Austria
12. ¹²Department of Pediatrics, Skejby Hospital, Aarhus University, Denmark
13. ¹³Department of Pediatric Immunology/Hematology and Stem Cell Transplantation, Leiden University Medical Center, Leiden, Netherlands
14. ¹⁴Hematology-Oncology Unit, Wilhelmina Children's Hospital, University Medical Center, Utrecht, Netherlands
15. ¹⁵Oncoematologia Pediatrica, IRCCS Policlinico San Matteo, Pavia, Italy

Correspondence: Dr A Yoshimi, Department of Pediatrics and Adolescent Medicine, Division of Pediatric Hematology and Oncology, University of Freiburg, Mathildenstrasse 1, Freiburg 79106, Germany. Fax: +49 0761 270 4623; E-mail: yoshimi@kikli.ukl.uni-freiburg.de

Received 30 November 2004; Accepted 4 February 2005; Published online 31 March 2005.

Abstract

Juvenile myelomonocytic leukemia (JMML) is a clonal myeloproliferative disorder of early childhood. In all, 21 patients with JMML who received donor leukocyte infusion (DLI) after allogeneic hematopoietic stem cell transplantation (HSCT) for either mixed chimerism (MC, n=7) or relapse (n=14) were studied. Six patients had been transplanted from an HLA-matched sibling and 15 from other donors. Six of the 21 patients (MC: 3/7 patients; relapse: 3/14 patients) responded to DLI. Response rate was significantly higher in patients receiving a higher total T-cell dose (1 10⁷/kg) and in patients with an abnormal karyotype. None of the six patients receiving DLI from a matched sibling responded. Response was observed in five of six patients who did and in one of 15 children who did not develop acute graft-versus-host disease following DLI (P=0.01). The overall outcome was poor even for the responders. Only one of the responders is alive in remission, two relapsed, and three died of complications. In conclusion, this study shows that some cases of JMML may be sensitive to DLI, this providing evidence for a graft-versus-leukemia effect in JMML. Infusion of a high number of T cells, strategies to reduce toxicity, and cytoreduction prior to DLI may improve the results.