Serial in vitro bone marrow cultures have been done on eight patients with acute lymphocytic leukemia. Colony-forming activity shows a rapid recovery from low values into the normal range in all patients who achieved stable remissions. Mean values for the stimulated cultures remained stable throughout consolidation, whereas the mean values for the unstimulated cultures declined during the same period. Relapse in two patients was preceded or accompanied by a concomitant decline in colony growth. Colony forming activity appears to be inhibited in a nonlinear fashion by increasing numbers of leukemic cells.

This content is only available as a PDF.
Sign in via your Institution