Evaluation of therapy in chronic lymphocytic leukemia using in vitro lymphocyte transformation

During the past several years, considerable interest has been generated in the short term in vitro culture of lymphocytes. Cytogeneticists have added the bean extract phytohemagglutinin to the cultures to stimulate cell division and thereby increase the number of mitoses available for examination. Empirically, the observation was made that this technic was relatively unsuccessful in the study of patients with chronic lymphocytic leukemia (1–4). Several investigators have since verified the failure of CLL (chronic lymphocytic leukemia) lymphocytes to undergo lymphoblastoid transformation and mitosis following cell culture stimulation with phytohemagglutinin (5–9). In the unstimulated culture of normal blood, the granulocytes degenerate and disappear. The small mature lymphocytes constitute the main cellular element in such cultures with some lymphocytes acquiring a monocytoid nature while others undergo a series of morphologic changes resembling macrophages engaged in phagocytosis. However, the primary lym...