Induction of cALL antigen and terminal deoxynucleotidyltransferase in normal peripheral lymphocytes during PHA...

In PHA cultures of peripheral lymphocytes from three healthy donors the extent and time sequence of cALL and TdT positivity was followed over a period of seven days. In all cases significant percentages of cALL+ and TdT+ cells were observed. However, the period of positivity for both these markers tended to be short. In contrast to previous results with the diffusion chamber system which yielded a comparatively uniform pattern of positivity, PHA cultures of the present cases revealed a more heterogeneous pattern concerning the extent as well as the time sequence of positivity. These experiments provide a broader basis for the notion that those markers are expressed during blastogenesis of normal lymphocytes which are generally regarded as indicative of early lymphatic differentiation and of the stage of developmental arrest of acute lymphatic leukemias.