Inherent Inability of Chronic Lymphocytic Leukaemia Lymphocytes to Respond to Phytohaemagglutinin

Abstract

The leukaemic cells from chronic lymphocytic leukaemia (CLL) patients are shown to be inherently unable to respond in vitro to phytohaemagglutinin (PHA). The response which occurs to PHA in CLL cultures is accounted for entirely by the small percentage of normal lymphocytes present among the leukaemic cells. The time curve of the delayed peak of DNA synthesis in PHA-stimulated CLL cultures is identical with that given by low concentrations of normal donors’ leucocytes. Morphological studies of PHA-stimulated CLL cultures and sex chromosome analysis of responding cells in PHA-stimulated cultures which contain both CLL and normal donor leucocytes confirm that the majority of lymphocytes in CLL blood do not undergo DNA synthesis or blastogenesis in response to PHA.