title: Circadian rhythms in arthritis: hormonal effects on the immune/inflammatory reaction.
abstract: Biological signaling and rhythms occur in a complex network with participation and interaction of the central nervous system, the autonomic nervous system, the endocrine glands, peripheral endocrine tissues and the immune system. It is a clinical observation that patients affected by chronic immune/inflammatory conditions (i.e. rheumatoid arthritis/RA) exhibit circadian, circamensual (females) and circannual rhythms of disease-related symptoms. Proinflammatory cytokines exhibit a peculiar rhythmicity, in particular serum TNF and serum IL-6, and together with other relevant immunological parameters display an elevation in the early morning hours in patients with RA. As a matter of fact, RA patients particularly experience joint pain, morning stiffness, and functional disability in the early morning hours. Since circadian rhythmicity of neuroendocrine pathways is closely coupled to immune/inflammatory reactions, new aspects at least concerning RA management are suggested. In particular, further investigations will indicate whether timed release of immunosuppressive/antiinflammatory drugs will have increased efficacy and whether dosages can be reduced below critical levels above which adverse events appear.
authors.affiliation: Research Laboratory and Academic Unit of Clinical Rheumatology, Department of Internal Medicine, University of Genova, Viale Benedetto XV, 6, IT-16132 Genova, Italy. mcutolo@unige.it
authors.forename: Maurizio
authors.initials: M
authors.lastname: Cutolo
authors.forename: Rainer H
authors.initials: RH
authors.lastname: Straub
mesh_terms: D001168:Arthritis / Q000276:immunology / Q000503:physiopathology*; D002940:Circadian Rhythm / Q000276:immunology*; D006728:Hormones / Q000097:blood*; D006801:Humans; D007249:Inflammation / Q000503:physiopathology
chemical_list: D006728:Hormones