Is there a circadian rhythm of interleukin 15 in Human?

Nine healthy young men were studied under strict conditions for 48h. The subjects were selected after a clinical examination and exploration of their rest-activity rhythm by actometry. The circadian rhythms of cortisol (peak at 8 AM) and melatonin (peak at 4 AM) were confirmed. The interleukin 15 (IL-15) was detected in the plasma samples with an Elisa kit (R&D System®), but no reproducible variation could be observed during day 1 and day 2. In conclusion, in the conditions of our study, no rhythm was observed for IL-15. Our population will be completed with the inclusion of 6 additional subjects. These results will be specified. [Copyright &y& Elsevier]