Residual Ph-negative stem cells in chronic myeloid leukemia--sometimes or always?
Some patients with Philadelphia (Ph) chromosome-positive chronic myeloid leukemia (CML) may achieve partially or completely Ph-negative hemopoiesis after treatment with high doses of cytotoxic drugs or interferon-alpha 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 cells be identified in all newly diagnosed patients or only in a minority? and 3) what is the basis for the proliferative advantage manifested by CML cells and why might it be temporarily lost as a result of treatment? The mechanisms that might prevent the 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 autografting with Ph-negative stem cells harvested during the recovery phase of high dose chemotherapy.
Goldman
J M
JM
Royal Posgraduate Medical School, Hammersmith, London, United Kingdom.
O'Brien
S G
SG
D006410:Hematopoiesis; D006412:Hematopoietic Stem Cells / Q000473:pathology*; D006801:Humans; D054438:Leukemia, Myeloid, Chronic, Atypical, BCR-ABL Negative / Q000473:pathology*