[Autologous bone marrow transplantation in chronic myelogenous leukemia]

Introduction of interferon-alpha therapy to chronic myelogenous leukemia (CML) has improved the survival rate of CML patients compared with conventional busulfan therapy. There still, however, are some IFN-resistant cases. To improve the survival rate of these IFN-resistant cases, bone marrow transplantation (BMT) has been tried at the world wide level. In cases without any allogeneic donors, autologous BMT is another choice. We recently have proposed the flow chart therapy system to select the auto-BMT candidates in CML patients. This system, briefly, consists of (1) bone marrow collection as early stage of CML as possible, (2) IFN-alpha treatment with administration of weekly methotrexate or occasional use of hydroxyurea, (3) early detection of accelerated or blastic phase of CML by using scoring system, (4) conditioning regimens of auto-BMT for CML and (5) post-BMT follow-up with IFN-alpha. Following this system, we have initiated the treatment of CML cases. Our tentative results on one case favorable outcome including complete disappearance of Ph1 positive clone. However, there are several questions to be answered in the auto-BMT for CML, namely, (1) do we need to purge Ph1 progenitor cells or not, if yes, how? (2) does the long term use of IFN affect the bone marrow microenvironment resulting in graft failure? Although our preliminary results gave some answers on these questions, further clinical and basic studies are required to obtain higher survival rates in CML treatment.