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Circadian rhythms play an important role in the function of the body. Among others, the activity of the immune system is subject to daily variability which explains the different intensity of rheumatic symptoms during the day (e.g. morning stiffness). Circadian rhythms are subject to continuous adaptation via external time signals (zeitgebers), such as light-dark periods, time of food intake, as well as daily activity and resting periods. Following an acute phase shift of these external zeitgebers, e.g. via transmeridian travel (east-west or west-east), the body has to adjust all circadian systems to these new circumstances during an adjustment response, which lasts for several days. The classical symptoms of jet lag, such as tiredness during the day, mood swings and cognitive malfunction occur during this adjustment period. The impact of acute phase shifts as a result of transmeridian travel in subjects with rheumatic disorders, as well as strategies to prevent jet lag will be discussed in the following article.

Clinical observations in chronic inflammatory diseases have demonstrated the significant influence of neuroendocrine mechanisms on the immune system: (1) Amelioration of rheumatoid arthritis during pregnancy; (2) preponderance of women versus men with respect to autoimmune diseases; (3) negative effects of ovulation-inducing therapy, oral contraceptives, and hormone replacement therapy; (4) protective effect of hemiplegia; (5) influence of psychological stress on inflammation; and (6) influence of circadian rhythms on inflammatory symptoms.The effects of different hormones and neurotransmitters on the immune system are influenced by: (1) the immune stimulus (foreign antigens or autoantigens) and subsequent antigen-specific immune responses, (2) the cell types involved during different phases of the disease, (3) the target organ with its specific microenvironment, (4) the timing of hormone or neurotransmitter increase in relation to the disease course, (5) the concentration of hormones and neurotransmitters, (6) the variability in expression of receptors depending on the microenvironment and the cell type, and (7) the intra- and extracellular peripheral metabolism of hormones and neurotransmitters leading to important biologically active metabolites with quite different anti- and proinflammatory functions.The circadian rhythm of disease-related symptoms with a peak in the early morning hours confirms that the neuroendocrine system has a strong influence on these chronic immune/inflammatory diseases. The influence is transmitted by the circadian fluctuation in the activity of hormonal and neuronal pathways linking the brain to immune cell activation.These considerations could lead to novel therapeutic strategies for rheumatic diseases in the future.

Ulcerative colitis is a multifactorial disease, with immunological, genetic, and environmental factors playing an important role in its pathogenesis. Here we investigated the consequences of exposure to chronic psychosocial stress on the severity of a dextran sulfate sodium (DSS)-induced colitis in male C57BL/6 mice. Chronic stress was induced by repeated exposure to social defeat (SD, 2 h) and overcrowding (OC, 24 h) during 19 consecutive days. SD/OC mice showed a diminished body weight gain, thymus-atrophy, and adrenal hypertrophy, but similar light-phase plasma corticosterone concentrations, compared with unstressed mice. In contrast, the rise in dark-phase corticosterone concentration was significantly attenuated in SD/OC mice, whereas plasma ACTH concentrations and hypothalamic CRH mRNA expression did not differ between stressed and nonstressed groups. Additionally, adrenal cells from SD/OC mice showed a decreased in vitro response to ACTH stimulation. Subsequent treatment with 1% DSS for 7 d resulted in a more severe intestinal inflammation in SD/OC mice, as reflected by an increase in body weight loss, histological damage scores, and secretion of IL-6, TNFalpha, and interferon-gamma from mesenteric lymph node cells and by decreased colon length. The impaired health status of stressed mice was also reflected by a significantly lower survival rate after termination of the DSS treatment. In conclusion, the present findings demonstrate that chronic intermittent exposure to a psychosocial stressor before the induction of acute DSS-colitis results in adrenal insufficiency, increases in the severity of the acute inflammation, and impairs the healing phase.

Dehydroepiandrosterone is a steroid hormone used as an 'over-the-counter' drug in the USA. Treatment with dehydroepiandrosterone was effective in randomized controlled trials in patients with systemic lupus erythematosus. Dehydroepiandrosterone sulphate concentrations are decreased in patients with inflammatory bowel disease. Dehydroepiandrosterone inhibits nuclear factor-kappaB and the secretion of interleukin-6 and interleukin-12 via the peroxisome proliferator-activated receptor alpha.A phase II pilot trial was started to evaluate the effect of dehydroepiandrosterone in active inflammatory bowel disease.Twenty patients with chronic active inflammatory bowel disease [seven Crohn's disease (Crohn's disease activity index, 242 +/- 51; mean +/- s.d.); 13 ulcerative colitis (clinical activity index, 7.8 +/- 2.1)] took 200 mg dehydroepiandrosterone per day orally for 56 days.Six of the seven patients with Crohn's disease and eight of the 13 patients with ulcerative colitis responded to treatment, with a decrease in the Crohn's disease activity index of70 points and a decrease in the clinical activity index of4 points, respectively. Six Crohn's disease patients and six ulcerative colitis patients went into remission (Crohn's disease activity index150; clinical activity indexor= 4). No patient withdrew from the study because of side-effects.In a pilot study, dehydroepiandrosterone was effective and safe in patients with refractory Crohn's disease or ulcerative colitis. Adjustment of the dehydroepiandrosterone dosage may further improve the treatment success.

Cytokines (IL-1, IL-6, IL-8, IL-11, TNF, IFN-gamma, and TGF-beta) and growth factors (EGF, bFGF, aFGF, and KGF) play an important role in modulation of hormone secretion by directly influencing specific enzyme steps of steroidogenesis in various endocrine cell types. For this tabular data collection, the following enzyme steps were considered: steroidogenic acute regulatory protein (StAR), side chain cleavage enzyme (P450scc), 3 beta-hydroxysteroid dehydrogenase, 17-alpha-hydroxylase/17,20-lyase (P450c17), 17-beta-hydroxysteroid-dehydrogenase, aromatase complex, 5-alpha-reductase, P450c21, DHEAS sulfatase, and DHEA sulfotransferase. This collection summarizes the current information on how the mentioned cytokines and growth factors influence particular enzyme steps.

During the last years, examination of autonomic nervous function and of autonomic neuropathy has attracted attention not only in diabetes mellitus research but also in other areas of internal medicine. However, patients with various chronic diseases with autoimmune phenomenons have never been investigated in a comparative study with standardized examination techniques. Hence, the aim of the study was to examine the prevalence and the severity of autonomic neuropathy in patients with the following chronic diseases.We investigated 28 patients with Crohn's disease (CD: age: 32.4 +/- 2.0 y), 17 patients with ulcerative colitis (UC: 39.7 +/- 3.6 y), 39 patients with systemic lupus erythematosus (SLE: 34.9 +/- 2.0 y), 38 patients with progressive systemic sclerosis (pSS; 51.5 +/- 2.4 y) and 65 patients with insulin-dependent diabetes mellitus (IDDM: 35.5 +/- 1.6 y). Cardiovascular autonomic (cANP), pupillary autonomic (pANP), and sensorimotor (ssNP) neuropathy were assessed by standardized techniques.Prevalence rates for cANP, pANP and ssNP were found to be 0%, 19%, and 7% in CD, 6%, 25%, and 18% in UC, 5%, 29%, and 10% in SLE, 11%, 16%, and 32% in pSS, and 26%, 66%, and 29% in IDDM, respectively.The study demonstrated patients with IDDM to have the highest prevalence rates of cANP and pANP. Patients with other chronic diseases, particularly SLE, pSS and UC, had high prevalence rates of pANP. This may be due to alterations of structures of the central nervous system in these patients. cANP was rare in patients with inflammatory bowel disease and ssNP was found very often in patients with pSS, probably due to local fibrotic lesions. The various disease groups differ in the pattern and severity of autonomic and sensorimotor neuropathy, which indicates that different structures and neuropathogenic mechanisms may be involved.