Residual Ph‐negative stem cells in chronic myeloid leukemia‐sometimes or always?

Abstract

Some patients with Philadelphia (Ph) hromosome‐positive chronic myeloid leukemia CML) may achieve partially or completely Ph‐negtive hemopoiesis after treatment with high doses of ytotoxic drugs or interferon‐α at standard dosage. This observation leads to three important questions: 1) are Ph‐negative myeloid cells in such patients strictly normal? 2) can such Ph‐negative ells be identified in all newly diagnosed patients or only in a minority? and 3) what is the basis for he proliferative advantage manifested by CML ells and why might it be temporarily lost as a result of treatment? The mechanisms that might prevent he proliferation of normal cells in an environment of Ph‐positive cells and the relevance of these questions to the design of a strategy aimed at obtaining complete remission in the majority of patients are considered. Such a strategy might incorporate auto‐grafting with Ph‐negative stem cells harvested during the recovery phase of high dose chemotherapy.