Kinetics of lymphokine production by lymphocytes from elderly humans

Production in vitro of the lymphokine leukocyte migration inhibition factor (LMIF) was studied for elderly as compared to young human subjects over an 8-day period of culture. When stimulated by either the antigen streptokinase/streptodornase (SK/SD) or the mitogen concanavalin A (Con A), the peak of LMIF production was retarded in cultures of lymphocytes from elderly subjects. Absolute peak values and numbers of positive responses were diminished in this group when the cells were stimulated with SK/SD but not with Con A. However, if LMIF production during the first 48-hour period was examined, the responses to Con A were also diminished in the elderly group. Retardation of lymphokine production by lymphocytes from elderly humans may be relevant to the assessment of immunologic competence in this group as well as to potential adverse effects on in vivo reactions of cell-mediated immunity.