The relationship of interleukin-1 and immune functions to sleep in humans.

Serial sampling of peripheral blood from six healthy adult male volunteers was performed during daytime waking and nighttime sleeping. In addition, sleep physiology was assessed in all subjects (Ss) and sleep stages scored blind by standard criteria. Samples of plasma were analyzed for cortisol (Co) levels, functional interleukin-1 (IL-1), and interleukin-2 (IL-2) activity. Peripheral blood monocytes (PBM) were assayed to evaluate natural killer (NK) activity and mitogen responsiveness. Dramatic increase in IL-1 activity along with changes in other immune functions occurred during sleep and were related to onset of slow wave sleep.