title: Seasonal variation in whole blood cytokine production after LPS stimulation in normal individuals.
abstract: We examined seasonal differences in whole blood cytokine production after endotoxin (LPS) stimulation in 17 healthy individuals from an urban area having normal sleep/wakefulness pattern. We used 500 pg/ml of LPS for incubation period of 4 h to stimulate 100 microl of whole blood of the same subjects in June, September, February, and March. We found no differences in the circulating total WBCs and differentials including monocytes between different seasons. We found during September (autumn) a reduced pro-inflammatory cytokine production in terms of TNF-alpha and IL-6 production compared to the other seasons. We also found a reduced anti-inflammatory cytokine production in June (summer) and September (autumn) in terms of IL-10, TNF-RI and TNF-RII compared to February (winter) and March (spring). Our results suggest that in early summer there is a predominating pro-inflammatory cytokine response which is counterbalanced early in autumn. These results may have significant implications in the determination of reference values, in exploration of immune response and inflammatory disease prevalence between different seasons, in determining LPS tolerance (immunoparalysis) and planning clinical trials and immunomodulary therapies. However, the effect of dark/light exposure differences on the circadian periodicity in the responsiveness of immune cells during different seasons should be further investigated.
authors: Athens University School of Nursing, ICU at KAT General Hospital, Nikis 2, 14561 Kifissia, Athens, Greece. pavlos_myrianthefs@hotmail.com
authors: Pavlos
authors: P
authors: Myrianthefs
authors: Stylianos
authors: S
authors: Karatzas
authors: Kyriaki
authors: K
authors: Venetsanou
authors: Elisabeth
authors: E
authors: Grouzi
authors: Penelope
authors: P
authors: Evagelopoulou
authors: Eleni
authors: E
authors: Boutzouka
authors: George
authors: G
authors: Fildissis
authors: Ioanna
authors: I
authors: Spiliotopoulou
authors: George
authors: G
authors: Baltopoulos
mesh_terms: D000276:Adjuvants, Immunologic / Q000494:pharmacology*; D000328:Adult; D016207:Cytokines / Q000097:blood / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D006801:Humans; D008070:Lipopolysaccharides / Q000494:pharmacology*; D012621:Seasons; D013997:Time Factors; D014409:Tumor Necrosis Factor-alpha / Q000187:drug effects
chemical_list: D000276:Adjuvants, Immunologic; D016207:Cytokines; D008070:Lipopolysaccharides; D014409:Tumor Necrosis Factor-alpha