RESUMEN
Lymphocytes from acute lymphocytic leukemia (ALL) subjects were converted by mitogens to blast-like cells whose microscopic appearance and rate of formation was indistinguishable from those in mitogen incubated control lymphocytes. In ALL lymphocytes, however, pokeweed mitogen (PWM) failed to stimulate GGT expression; the mean increase it caused in thymidine kinase (TK) activity and thymidine incorporation was normal, though there were appreciable individual variations. These variations were also apparent with concanavalin A (Con A) but, in most ALL cases, TK and thymidine incorporation rose to much higher levels than in Con-A-treated control lymphocytes. The results indicate that evaluation of the response to mitogens by quantitative biochemical criteria provides a sensitive method for revealing functional impairments in microscopically normal ALL lymphocytes.