SUCCESSFUL AUTOGRAFTING IN CHRONIC MYELOID-LEUKEMIA AFTER MAINTENANCE OF MARROW IN CULTURE

Abstract

We have previously shown that Philadelphia chromosome (Ph1)-positive cells rapidly disappear when marrow from patients with chronic myeloid leukemia (CML) is cultured under conditions that maintain normal haematopoiesis for many weeks. The ability of marrow maintained in culture for 10 days to serve as an autograft has now been tested in three patients treated with intensive chemoradiotherapy. Two weeks after transplantation, marrow samples from all patients showed trilineage haematopoiesis. Neutrophil counts > 1.0 .times. 109/l were achieved in all patients within 4 weeks, and platelet counts > 20 .times. 109/l were achieved in two patietns within 5 weeks. During this period of haematopoietic recovery, marrow cells were exclusively Ph1-negative in two patients and predominantly so in the third. These results suggest that engraftment can occur from Ph1-negative haematopoietic stem cells selected by maintenance of autologous CML marrow in culture for 10 days. Thus, the feasibility of using this approach to allow intensive and potentially curative therapy for CML has been established.