@article{3004778,
    title = "Seasonal variation in whole blood cytokine production after LPS stimulation in normal individuals",
    author = "Myrianthefs, P. and Karatzas, S. and Venetsanou, K. and Grouzi, E. and Evagelopoulou, P. and Boutzouka, E. and Fildissis, G. and Spiliotopoulou, I. and Baltopoulos, G.",
    journal = "Cytokine",
    year = "2003",
    volume = "24",
    number = "6",
    pages = "286-292",
    publisher = "INSTAP Academic Press",
    issn = "1043-4666, 1096-0023",
    doi = "10.1016/j.cyto.2003.08.005",
    keywords = "bacterium lipopolysaccharide;  Escherichia coli endotoxin;  interleukin 6;  tumor necrosis factor alpha;  tumor necrosis factor receptor 1;  tumor necrosis factor receptor 2, adult;  article;  autumn;  blood level;  controlled study;  cytokine production;  female;  human;  human experiment;  immunostimulation;  incubation time;  leukocyte;  male;  monocyte;  normal human;  priority journal;  seasonal variation;  sleep waking cycle;  urban area",
    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 μl 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-α 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. © 2003 Elsevier Ltd. All rights reserved."
}