Myelodysplastic syndrome (MDS) is a rare, clonal abnormality of the pluripotent haematopoietic stem cell. Stem cell transplantation (SCT) is the only curative treatment modality which has been for a long time connected with high transplant related mortality and relapse. The Czech Republic participates in the international study EWOG-MDS. In this study children are indicated to SCT early using a very intensive myeloablative conditioning regimen comprising 3 alkylating agents – busulfan, cyclophosphamide and melphalan. Between 1997–2002, 14 children with primary MDS (JMML: 5, RC: 4, RAEB: 2, RAEBt: 2, MDSr-AML: 1) were transplanted from HLA identical siblings (n = 7) or unrelated donors (n = 7). Median age at the SCT was 5.8 years; median time from diagnosis to SCT was 5 months. A conditioning regimen of 3 alkylating agents was used in 12 children; two patients with refractory cytopenia were transplanted from unrelated donors using a non-myeloablative conditioning regimen of fludarabin and thiotepa. As GVHD prophylaxis cyclosporin was used alone (n = 5) or in combination with methotrexate (n = 7) or steroids (n = 1). All patients engrafted. Acute GVHD grades II–IV developed in 57 % patients and extensive chronic GVHD in 20 % children. Four children (28.5 %) died due to transplant related causes and one patient (7 %) after syngeneic SCT developed a relapse treated by a second SCT from an unrelated donor. After amedian follow-up of 1.9 years, 10 children (71 %) are alive in complete remission. Allogeneic SCT performed according to the EWOG-MDS recommendations improved significantly the prognosis of children with MDS in the Czech Republic.

        Key words: myelodysplastic syndrome, children, stem cell transplantation, relapse, graft-versus-host disease