Sister chromatid exchange and cell cycle progression in cultured lymphocytes from patients with chronic lymphatic leukemia.

Sister chromatid exchange (SCE) was significantly increased in patients who had chronic lymphatic leukemia (CLL) and who had received therapy compared with untreated patients and normal controls. Elevated SCE appeared to be a function of the therapy and not the leukemia. Differential chromatid staining was used to identify successive cell reproduction cycles. In comparison to normal lymphocytes, the cells responding to phytohemagglutinin in CLL cultures showed no evidence of retarded progression through successive cell cycles.