Respiratory infection risk in athletes: association with antigen-stimulated IL-10 production and salivary IgA secretion. Scand J Med Sci Sports
School of Sport, Exercise and Health Sciences, Loughborough University, Leicestershire, UK.Scandinavian Journal of Medicine and Science in Sports (Impact Factor: 2.9). 03/2011; 22(3):410-7. DOI: 10.1111/j.1600-0838.2010.01272.x
The purpose of this study was to examine factors influencing susceptibility to upper respiratory tract infections (URTI) in 18-35-year-old men and women engaged in endurance-based physical activity during the winter months. Eighty individuals (46 males, 34 females) provided resting blood and saliva samples for determination of markers of systemic immunity. Weekly training and illness logs were kept for the following 4 months. Thirty subjects did not experience an URTI episode and 24 subjects experienced 3 or more weeks of URTI symptoms. These illness-prone subjects had higher training loads and had ∼2.5-fold higher interleukin (IL)-4 and IL-10 production by antigen-stimulated whole blood culture than the illness-free subjects. Illness-prone subjects also had significantly lower saliva S-IgA secretion rate and higher plasma IgM (but not IgA or IgG) concentration than the illness-free subjects. There were no differences in circulating numbers of leukocyte subtypes or lymphocyte subsets between the illness-prone and illness-free subjects. The production of IL-10 was positively correlated and the S-IgA secretion rate was negatively correlated with the number of weeks with infection symptoms. It is concluded that high IL-10 production in response to antigen challenge and low S-IgA secretion are risk factors for development of URTI in physically active individuals.
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- "Changes flagged in a small-scale analysis here, such as exceedance of one year is assumed to be a tolerable change, since the undesired outcome, the loss of a fish population, did not occur. Acute changes, however, may not be insubstantial with the intersection of rare and exacerbating events, such as the impact of exposure of some individuals to pathogens when physically exhausted (Gleeson et al. 2012). More research on this topic is clearly required. "
ABSTRACT: Detecting unwanted changes associated with localized human activities in aquatic ecosystems requires defining the value of an indicator expected at a site in the absence of development. Ideally, adequate and comparable baseline data will be collected at an exposure location prior to that development, but this is rarely done. Instead, comparisons are made using various designs to overcome the inadequate or missing baseline data. Commonly these comparisons are done over short time periods using information from local reference sites to estimate variability expected at the exposed site. These truncated designs are often evaluated using p-values that may have little bearing on ecologically relevant changes. To remedy the reliance of studies on small datasets collected at reference sites, other designs emphasize regional analyses, but these may be insensitive to site-specific changes. Some designs may also forego discussing the consequences of detecting any differences. A new monitoring framework has been proposed to utilize existing solutions, simplify analysis, and focus on the detection of meaningful changes. It is illustrated here using data on fish health from a large-scale, long-term program in the Moose River basin in northern Ontario. This framework advocates interpretation of data at multiple scales: within-site, locally, and regionally. Primary focus is on estimating a range from a probability distribution of historical data collected at a specific location where 95% of future observations are predicted to occur. Changes at the exposed site are also compared to historical and contemporary expectations from proximate and regional reference sites. Critical effect sizes can also be derived from regional reference data to evaluate the magnitude of differences observed between any two sites. Any unexpected changes inform future monitoring decisions provided by a priori guidance. Adoption of this framework extends the utility of monitoring programs where commitments to long term collections have been made, advocates harmonization of studies over time and space, and focuses attention on unusual observations. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.
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- "Indeed, periods of intense, frequent, endurance-based training have consistently been associated with self-reported symptoms of URTI in elite-level athletes (Gleeson 2000;Gleeson et al. 1999;Gleeson and Pyne 2000;Nieman 2000). Low levels of salivary secretory immunoglobulin A (SIgA) have been linked with an increased risk of URTI (Fahlman and Engels 2005;Gleeson et al. 1999Gleeson et al. , 2012Hanson et al. 1983;Neville et al. 2008) and prolonged, high-intensity exercise bouts lower both the concentration and secretion of salivary SIgA (Fahlman et al. 2001;Nieman et al. 2006;Steerenberg et al. 1997;Tomasi et al. 1982;Usui et al. 2011). On the other hand, shorter exercise bouts, or low to moderate-intensity exercise, may actually increase salivary SIgA concentration and secretion (Allgrove et al. 2008;Li and Gleeson 2004), indicating that mucosal immune integrity, and indeed URTI risk, is dependent on the duration and intensity of the exercise performed. "
ABSTRACT: Purpose: Salivary antimicrobial proteins (sAMPs) protect the upper respiratory tract (URTI) from invading microorganisms and have been linked with URTI infection risk in athletes. While high training volume is associated with increased URTI risk, it is not known if fitness affects the sAMP response to acute exercise. This study compared the sAMP responses to various exercising workloads of highly fit experienced cyclists with those who were less fit. Methods: Seventeen experienced cyclists (nine highly fit; eight less fit) completed three 30-min exercise trials at workloads corresponding to -5, +5 and +15 % of the individual blood lactate threshold. Saliva samples were collected pre- and post-exercise to determine the concentration and secretion of α-amylase, human neutrophil proteins 1-3 (HNP1-3) lactoferrin, LL-37, lysozyme, and salivary SIgA. Results: The concentration and/or secretion of all sAMPs increased post-exercise, but only α-amylase was sensitive to exercise workload. Highly fit cyclists had lower baseline concentrations of α-amylase, HNP1-3, and lactoferrin, although secretion rates did not differ between the groups. Highly fit cyclists did, however, exhibit greater post-exercise increases in the concentration and/or secretion of a majority of measured sAMPs (percentage difference between highly fit and less fit in parentheses), including α-amylase concentration (+107 %) and secretion (+148 %), HNP1-3 concentration (+97 %) and secretion (+158 %), salivary SIgA concentration (+181 %), lactoferrin secretion (+209 %) and LL-37 secretion (+138 %). Conclusion: We show for the first time that fitness level is a major determinant of exercise-induced changes in sAMPs. This might be due to training-induced alterations in parasympathetic and sympathetic nervous system activation.
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- "Aliquots were subsequently diluted with RPMI 1640 medium for use in the in vitro incubations. Stimulated whole blood and PBMC culture production of cytokines (IFN-í µí»¾, TNF-í µí»¼, IL-1í µí»½, IL-2, IL-4, IL-6, and IL-10) were determined as described previously . Briefly, for the determination of baseline unstimulated cytokine production, 0.25 mL of heparinized whole blood or PBMC were added to 0.75 mL of RPMI 1640 medium and incubated at 37 "
ABSTRACT: Aim. Our aims were to determine the influence of plasma total 25-hydroxy vitamin D (25(OH)D) status on the plasma cytokine concentrations in athletes and the in vitro effects of different doses of 1, 25 dihydroxyvitamin D3 (1, 25(OH)2D3) on multiantigen stimulated cytokine production by whole blood and peripheral blood mononuclear cell (PBMC) cultures. Methods. Plasma samples from 43 athletes with high and low levels of 25(OH)D were assayed for the concentrations of cytokines. The whole blood samples and PBMCs from healthy subjects were incubated in vitro with a multi-antigen vaccine and different doses of added 1, 25(OH)2D3. The circulating cytokines and stimulated whole blood and PBMC culture production of cytokines were determined using a biochip assay. Results. The circulating interleukin-(IL-)10 and interferon-(IFN-) γ concentrations were significantly higher in the vitamin D sufficient athletes. Furthermore, the production of tumour necrosis factor-(TNF-) α, IL-6, IFN-γ, IL-2, and IL-10 by whole blood culture was significantly inhibited by 1, 25(OH)2D3 concentrations of 1000 pmol/L or 10000 pmol/L. Conclusions. We found that the influence of vitamin D on circulating cytokines might be different in athletes compared with nonathletes and cytokines production by whole blood culture was not influenced by 1, 25(OH)2D3 in concentrations within the normal healthy range.
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