Long-Term Marrow Culture Reveals Chromosomally Normal Hematopoietic Progenitor Cells in Patients with Philadelphia Chromosome-Positive Chronic Myelogenous Leukemia

Abstract
We found that when marrow cells from four patients with newly diagnosed Philadelphia Chromosome-Positive chronic myelogenous leukemia were maintained in culture for two to four weeks, a previously undetectable population of chromosomally normal hematopoietic cells (including erythroid, granulopoietic, and pluripotent progenitors) became readily demonstrable in three cases. Time-course studies showed that in such cultures the dominant Philadelphia Chromosome-Positive population rapidly disappeared, in contrast to coexisting chromosomally normal progenitors, which remained detectable for periods of two to three months. Long-term marrow cultures thus offer a new approach to the assessment of a suppressed but functionally intact population of chromosomally normal hematopoietic stem cells in patients with chronic myelogenous leukemia. (N Engl J Med 1983; 308:1493–8.)