TREATMENT OF JUVENILE CHRONIC MYELOMONOCYTIC LEUKEMIA BY ALLOGENEIC BONE-MARROW TRANSPLANTATION

Twelve of 15 patients with juvenile chronic myelomonocytic leukemia (J CMML) referred to our unit underwent allogeneic bone marrow transplant ation (BMT) between 1982 and 1992. BMT was not performed in the remain ing three cases because of poor overall condition in two and disease p rogression in one. Six patients received marrow from HLA-identical sib lings after a chemotherapy conditioning regimen in five cases. BMT fai led in one case. Long-term remission was achieved in three patients an d two others are in remission 6 and 11 months after BMT. Remission was associated with autologous recovery in one patient and minimal mixed chimerism in another. In one patient, a first BMT procedure resulted i n autologous recovery and relapse. A second transplant, with chemother apy conditioning including TBI, was successful. BMT with marrow from a matched unrelated donor was also successful. In contrast, BMT with ma rrow from mismatched related donors (five patients) failed because of graft failure and/or relapse. This single-center series indicates that HLA-identical BMT is an appropriate treatment for JCMML. However, on the basis of these results it cannot be ascertained whether chemothera py or splenectomy are necessary prior to BMT. The best chemotherapy co nditioning regimen remains to be defined, as regimens consisting exclu sively of chemotherapy resulted either in long-term remission or in au tologous recovery with relapse.