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Exercise-induced bronchoconstriction (EIB) is a prevalent condition in elite athletes caused by transient airway narrowing during or after exercise. Young athletes nowadays start early to perform high level exercise, highlighting the need to screen for EIB in a younger population. The purpose of this review is to evaluate current evidence of pre-tests with high probability to predict a positive provocation test in young and adolescent athletes, aged 12–24 years and thus indicate whether a young athlete is at risk of having EIB. Up to now, there is no validated screening test available to increase the pre-test probability of a provocation test of EIB in young and adolescent athletes. We would recommend that a clinical guideline committee might consider the development of a flow chart to screen for EIB in adolescent athletes. It could be composed of a symptom-based questionnaire focusing on wheezing during exercise, atopic state, reversibility test (to exclude EIB with asthma) and completed with markers in blood/serum. However, more research is necessary.

Background: Staphylococcus aureus colonization and release of enterotoxin B (SEB) has been shown to contribute to the pathogenesis of chronic rhinosinusitis with nasal polyps (CRSwNP), but the pathogenic mechanisms are largely unknown. Methods: We investigated the effect of SEB on nasal epithelial function in vitro on primary polyp and nasal epithelial cells of patients with CRSwNP and healthy controls respectively, and in vivo in a mouse model by measuring epithelial integrity and tight junction expression. The involvement of TLR2 signaling was studied in vitro by using TLR2 monoclonal antibodies and in vivo in tlr2-/- transgenic mice. Findings: We found that in vitro stimulation with SEB decreased polyp epithelial integrity by reducing occludin and ZO-1 protein expression. This impaired barrier function was associated with elevated expression of epithelial TLR2 and antagonizing TLR2 triggering prevented SEB-induced barrier disruption in vitro. In wild type mice, SEB applied in the nose increased mucosal permeability and decreased occludin and ZO-1 mRNA expression, whereas tlr2-/- mice had an intact mucosal barrier and normal tight junction expression after SEB exposure. Furthermore, in vitro SEB stimulation resulted in epithelial production of IL-6, IL-8 and TNF, which was prevented when TLR2 triggering was antagonized. Interpretation: Our results indicate that SEB impairs epithelial barrier function in CRSwNP via TLR2 activation. Interfering with TLR2 activation may provide a way to avoid the pathophysiological consequences of S. aureus colonization in CRSwNP. Funding Statement: The author’s laboratories are supported by grants from the Belgian Federal Government (IUAP P7/30), IWT (TBM project 130260) and the research council of the KU Leuven (GOA 14/011). PWH, RS and DMB are recipients of a senior researcher fellowship from the Fund of Scientific Research (FWO), Flanders, Belgium. BS is currently a Postdoctoral Fellow of the Fund for Scientific Research Flanders (FWO). Declaration of Interests: The authors declare no competing interest related to this work. Ethics Approval Statement: All experiments were approved by the Medical Ethical Committee of the University Hospitals Leuven. Murine experiments were approved by the Ethical Committee for Animal Research at the KU Leuven.

SummaryOne of the theories which explain, why gastroesophageal reflux disease (GORD) may provoke cough, is the occurrence of aspiration of gastric content into the airways. The aim of the study was to assess the presence of aspiration markers: pepsin and bile acids (BA) in induced sputum in gastroesophageal reflux-related (GOR-related) chronic cough (CC) patients. Forty-one CC patients and 20 healthy controls were enrolled in the study. GORD as cause of CC was diagnosed by presence of GORD-related symptoms, gastroscopy and/or improvement of cough upon treatment with proton pump inhibitors (PPI). Patients were divided into two groups based on the response to PPI treatment. In all patients and healthy controls induced sputum was obtained and differential cell counts were calculated. Levels of pepsin and BA were measured in sputum supernatants. Pepsin was detectable in 48.8% samples in CC patients and in 60% healthy controls (p = NS). In pepsin positive samples no significant difference in pepsin concentration could be found between CC patients and control subjects. Pepsin levels in pepsin positive samples were significantly decreased in patients treated with PPI compared to non-treated patients. BA were detectable in 56% samples of CC patients and in 70% healthy controls (p = NS). BA concentration in BA positive samples in CC group was not different from healthy controls. There was also no difference when comparing patients who took PPI and those who did not. Patients characterized as PPI-responders and PPI-non-responders had similar pepsin and BA concentrations. Airway cellularity was not significantly different between groups of patients with or without pepsin or BA in induced sputum. Our results demonstrated the lack of differences in gastric content aspiration between patients with probable GOR-related CC and healthy control subjects. This might imply that the reflex cough theory may be more relevant than the reflux-associated aspiration theory in the pathophysiology of GORinduced chronic cough.

Bronchiolitis obliterans syndrome (BOS) is the leading cause of death after lung transplantation. Treatment is challenging, as the precise pathophysiology remains unclear. We hypothesize that T(H)17 lineage plays a key role in the pathophysiology of BOS by linking T-cell activation to neutrophil influx and chronic inflammation. In a cross-sectional study, bronchoalveolar lavage (BAL) samples of 132 lung transplant recipients were analyzed. Patients were divided in four groups: stable or suffering from infection (INF), acute rejection (AR) or BOS. The upstream T(H)17 skewing (TGF-beta/IL1beta/IL6/IL23), T(H)17 counteracting (IL2), T(H)17 effector cytokine (IL17) and the principal neutrophil-attracting chemokine (IL8), were quantified at the mRNA or protein level in combination with the cell profiles. The BOS group (n = 36) showed an increase in IL1beta protein (x1.5), IL6 protein (x3), transforming growth factor-beta (TGF-beta) mRNA (x3), IL17 mRNA (x20), IL23 mRNA (x10), IL8 protein (x2), IL8 mRNA (x3) and a decrease in IL2 protein (x0.8). The infection group (n = 11) demonstrated an increase in IL1beta protein (x5), IL6 protein (x20), TGF-beta mRNA (x10), IL17 mRNA (x300), IL23 mRNA (x200) and IL8 protein (x6). The acute rejection group (n = 43) only revealed an increase in IL6 protein (x6) and IL8 protein (x2) and a decrease in IL2 protein (x0.7). Lymphocytes and neutrophils were increased in all groups compared to the stable (n = 42). Our findings demonstrate the IL23/IL17 axis to be involved in the pathophysiology of BOS potentially triggering the IL8-mediated neutrophilia. IL6, IL1beta and IL23 seem to be skewing cytokines and IL2 a counteracting cytokine for T(H)17 alignment. The involvement of TGF-beta could not be confirmed, either as T(H)17 steering or as counteracting cytokine. ispartof: American Journal of Transplantation vol:8 issue:9 pages:1911-1920 ispartof: location:United States status: published

P030 High fat diet aggravates Crohn’s disease-like ileitis independently of obesity via alterations of epithelial barrier homeostasis L. Gruber1 *, S. May1, J. Fiamoncini2, V. Muller2, M. Lichtenegger3, M. Rychlik3, H. Daniel2, D. Haller1. 1Technical University Munich, Biofunctionality, ZIEL Research Center for Nutrition and Food Sciences, CDD Research Center for Diet and Disease, Freising, Germany, 2Technical University Munich, Department of Biochemistry, ZIEL Research Center for Nutrition and Food Sciences, Freising, Germany, 3Technical University Munich, Bioanalytics, ZIEL Research Center for Nutrition and Food Sciences, Freising, Germany

Rationale We aimed to investigate the role of CD4+ cells in the bronchial late phase response (LPR) in a mouse-model of asthma, characterized by an allergen-specific LPR. Methods Male Balb/C mice (6–8 weeks) were sensitized by ovalbumin (OVA) (i.p.) on alternate days from d1 till d13. The challenge phase comprised daily nebulizations of OVA from d33 till d40. On d47 500ul PBS (control) or 100 μg GK1.5 (depleting anti-CD4 monoclonal antibody) was administered i.p. The LPR was induced by nebulized OVA on d50. The enhanced pause (PenH) was measured every 30 seconds during 6 hours by body plethysmography. The mice were sacrificed for flowcytometric analysis of whole blood, differential cell counts and cytokine measurements on broncho-alveolar lavage (BAL), and for RT-PCR on lung tissue. Results Within the CD3+ population, GK1.5 diminished the CD4+ cells by more than 90%. In the control mice an LPR could be induced with PenH peaking at 240 min whereas in the GK1.5 group the LPR was inhibited. The area under the curve of the PenH/time curve was lower in the GK1.5 mice compared to the control mice (p=0.03, t-test). BAL lymphocyte, monocyte and eosinophil counts were lower in the GK1.5 group (p=0.03, p=0.03 and p=0.02 respectively, t-test). BAL IFN-γ was lower in the GK1.5 group (p=0.02, t-test). IL-4, IL-5 and IFN-γ-mRNA tended to be decreased in the GK1.5 group. Conclusions Blocking/depleting of CD4+ cells inhibits the LPR in a mouse model of asthma. Thus, CD4+ lymphocytes might play a key role in the induction of the bronchial LPR.