title: Twenty-four-hour analysis of lymphocyte subpopulations and cytokines in healthy subjects.
abstract: Fourteen healthy male subjects were studied under resting conditions for 24 or 48 h. The 24-h variations of ACTH and cortisol with peaks in the morning were confirmed. Interleukin-2 release was profoundly reduced at 8: 00. A cosine function could be fitted to lymphocyte subpopulations including populations such as T helper-memory cells (CD4+/CDw29) and HLA-DR-bearing cells displaying peak values during the night and minimal values at 9:00. Numbers of natural killer cells (CD57) were not correlated to other cell populations and no rhythm could be detected. Interleukin- 1 beta was detectable in some plasma samples only with an interleukin- 1 ELISA kit (Quantakine HS(R)), but neither a 24-h rhythm nor reproducible results could be obtained for day 1 and 2 of the study. We conclude that there might be a temporal relation between the parameters analyzed: Higher levels of endogenous cortisol in the morning hours probably inhibit the cellular interleukin-2 synthesis and are responsible for an enhanced migration of lymphocytes from the blood into the tissues of the reticuloendothelial system. These results might be indicative of a circadian organization of the immune system which may play a role in both physiological and pathological functioning.
authors.affiliation: Clinic of Anaesthesiology und Operative Intensive Care, Christian-Albrechts-University, Kiel, Germany.
authors.forename: S
authors.initials: S
authors.lastname: Palm
authors.forename: E
authors.initials: E
authors.lastname: Postler
authors.forename: H
authors.initials: H
authors.lastname: Hinrichsen
authors.forename: H
authors.initials: H
authors.lastname: Maier
authors.forename: P
authors.initials: P
authors.lastname: Zabel
authors.forename: W
authors.initials: W
authors.lastname: Kirch
mesh_terms: D000324:Adrenocorticotropic Hormone / Q000097:blood; D000328:Adult; D002940:Circadian Rhythm / Q000276:immunology*; D016207:Cytokines / Q000097:blood*; D006801:Humans; D006854:Hydrocortisone / Q000097:blood; D066298:In Vitro Techniques; D007375:Interleukin-1 / Q000097:blood; D007376:Interleukin-2 / Q000097:blood; D018655:Lymphocyte Count; D016131:Lymphocyte Subsets / Q000276:immunology*; D008297:Male; D010835:Phytohemagglutinins / Q000494:pharmacology
chemical_list: D016207:Cytokines; D007375:Interleukin-1; D007376:Interleukin-2; D010835:Phytohemagglutinins; D000324:Adrenocorticotropic Hormone; D006854:Hydrocortisone