Bone marrow transplantation in accelerated chronic granulocytic leukaemia using dibromomannitol-preconditioning instead of total-body irradiation.

In a preliminary study on five patients with accelerated CGL, transplantation of allogeneic matched bone marrow was shown to be feasible without whole-body irradiation. Animal experiments and studies with cells cultured in vitro suggest that the cytocastic drug used to kill leukaemic clones (Myelobromol-Chinoin) does not injure haemopoietic stroma. The administration of this protocol is cheap and easy. Our preconditioning does not, in itself, eradicate the malignant CGL clone immediately: 15-20% of marrow mitoses were Ph1+ one month after transplantation. For this reason, additional cytostatic therapy was given in the course of the 3rd to 6th post-transplant months. No Ph1+ cells were observed from the fourth post-transplant month onwards. Very few severe acute complications were seen and two out of three matched transplanted patients are disease-free 27 + and 13 + months later. On the basis of the developing normal spleen architecture and the changing pattern of circulating NAP score values, particularly the months-long persistence of distinctly low scores, and then the delayed emergence of normal levels, we put forward a hypothesis, emphasizing the role of environmental factors, including the formation of a normal haemopoietic stroma in the successfully transplanted CGL patient.