All issues > Volume 48(2); 2005

Original Article

Korean J Pediatr. 2005;48(2):178-185. Published online February 15, 2005.

Allogeneic Hematopoietic Stem Cell Transplantation in Juvenile Myelomonocytic Leukemia

Keon Hee KH Yoo¹, Dong Kil DK You¹, Soo Hyun SH Lee¹, Ki Woong KW Sung¹, Eun Joo EJ Cho¹, Hong Hoe HH Koo¹

¹Department of Pediatrics, Samsung Seoul Hospital, Sungkyunkwan University School of Medicine, Seoul, Korea

Correspondence Hong Hoe HH Koo ,Email: hhkoo@smc.samsung.co.kr

Abstract

Purpose
: The purpose of this study was to evaluate the outcome of children with juvenile myelomonocytic leukemia(JMML) treated with allogeneic hematopoietic stem cell transplantation(allo- HSCT).
Methods
: Eleven JMML patients aged 8-39 months underwent allo-HSCT. The sources of grafts were unrelated donors(n=7), HLA-matched siblings(n=3) and an HLA 1-antigen mismatched familial donor. All patients had received chemotherapy ?13-cis-retinoic acid(CRA) before transplant, and CRA was used, posttransplant, in six patients.
Results
: Only three patients were in complete remission(CR) at the time of transplantation. Initial chimeric status revealed complete donor chimerism(CC) in five patients, mixed chimerism(MC) in five and autologous recovery(AR) in one. One patient with MC having persistent splenomegaly eventually turned to CC and CR after rapid tapering of cyclosporine, combined with daily use of CRA. An AR case relapsed shortly after transplant but was rescued with second, unrelated cord blood transplantation. Ultimately, six patients are alive, event-free, with a median follow-up of 15.5 months posttransplant. All three deaths occurred in patients who failed to achieve CC, leading to disease progression.
Conclusion
: We suggest that graft-versus-leukemia effect play an important role and CRA a possible role in posttransplant leukemic involution in JMML. In patients whose leukemic burden is still high with MC after transplant, early tapering of immunosuppressants and introduction of CRA might provide a chance of a cure for some patients.

Keywords :Juvenile myelomonocytic leukemia , Allogeneic hematopoietic stem cell transplantation , 13-cis-retinoic acid , Graft-versus-leukemia effect