Lymphocytes are rhythmic: is this important?

Seasonal modulation of the circadian time structure of circulating T and natural killer lymphocyte subsets from healthy subjects.

“…Moreover, a 12-h rhythm in both OKT8+ and HNK1+ lymphocytes was observed on 4 and 3 mo of study, respectively, including March, with similar rhythm characteristics. Of 15 reports in which circadian changes in the peripheral lymphocyte count are described, the season of study is only given in five (including three by us) (16)(17)(18)(19)(20)(21)(22)(23)(24)(25)(39)(40)(41)(42)(43). Ofthose, none was performed in March or in June.…”

Personalized Therapy for Metastatic Melanoma: Could Timing Be Everything?

“…Later studies in humans suggested a diurnal rhythmicity in cytokine production [22], as well as pronounced circadian rhythms of immune cell subpopulations, which are hormonally modulated via the hypothalamic–pituitary–adrenal axis [20]. Several of the observed variations were so large [20], that some researchers questioned whether the normal range for these variables should specify a time for collection (similar to hormone measurements in endocrinology), if the normal range is to be at all meaningful [23]. Previously mentioned studies suggest that the circadian rhythms of various cytokines and immune cell subpopulations differ considerably with respect to peak times and amplitudes, with some immunological variables showing acrophases during the night, while others peak during the day.…”

Abnormal distribution of CD8 subpopulation in B-chronic lymphocytic leukemia identified by flow cytometry

“…Flow cytometric analysis was performed the same day to preserve both optimal binding of monoclonal antibody and light scatter properties of lymphocytes [19,20].…”