Elevated sister chromatid exchange and cell cycle analysis in bone marrow in childhood ALL

Sister chromatid exchange (SCE) frequencies were analyzed in both stimulated and unstimulated bone marrow samples from eight patients recently found to have childhood acute lymphocytic leukemia (ALL). Six of the patients had elevated SCE frequencies in stimulated marrow when compared to control values. In unstimulated marrow, all four patients had elevated SCE frequencies. These data agree with peripheral leukocyte findings in ALL. Cell cycle analysis revealed no significant differences between the patient marrows and the control marrows. Since no correlation between cell cycle distribution and SCE frequency was found, it is suggested that the differences in SCE observed may be related to the type of proliferating cell.