Non-allergic Healthy Controls Research Articles

Phenotype-specific signatures of systems-level gut microbiome associated with childhood airway allergies.

Perturbation of gut symbiosis has been linked to childhood allergic diseases. However, the underlying host-microbe interaction connected with specific phenotypes is poorly understood. To address this, integrative analyses of stool metagenomic and metabolomic profiles associated with IgE reactions in 56 children with mite-sensitized airway allergies (25 with rhinitis and 31 with asthma) and 28 nonallergic healthy controls were conducted. We noted a decrease in the number and abundance of gut microbiome-encoded carbohydrate-active enzyme (CAZyme) genes, accompanied with a reduction in species richness, in the asthmatic gut microflora but not in that from allergic rhinitis. Such loss of CAZymes was consistent with the observation that a CAZyme-linked decrease in fecal butyrate was found in asthmatics and negatively correlated with mite-specific IgE responses. Different from the CAZymes, we demonstrated an increase in α diversity at the virulome levels in asthmatic gut microbiota and identified phenotype-specific variations of gut virulome. Moreover, use of fecal metagenomic and metabolomic signatures resulted in distinct effects on differentiating rhinitis and asthma from nonallergic healthy controls. Overall, our integrative analyses reveal several signatures of systems-level gut microbiome in robust associations with fecal metabolites and disease phenotypes, which may be of etiological and diagnostic implications in childhood airway allergies.

Phenotype‐specific signatures of gut microbiome, resistome, virulome, and metabolome associated with childhood airway allergies

Perturbation of gut dysbiosis has been linked to childhood allergic diseases. However, the association of fecal microbiome and metabolite profiles with specific phenotypes is poorly understood. To address this, we performed shotgun sequencing of intestinal microbiome and untargeted metabolomics profiling of fecal samples in a cohort of children mite‐sensitized airway allergies (25 with rhinitis and 31 with asthma) and 28 non‐allergic healthy controls. An integrative analysis of stool metagenomic and metabolomic profiles associated with IgE reactions in childhood allergic rhinitis and asthma was conducted. We noted a decrease in the number and abundance of gut microbiome‐encoded carbohydrate‐active enzyme (CAZyme) genes, accompanied with a reduction of within‐sample species richness (α diversity), in the asthmatic gut microbiome but not in that from allergic rhinitis. Such loss of CAZymes was consistent with the observation that decreased levels of butyrate and fumarate (a metabolic precursor of propionate) were detected in the fecal samples of asthmatics. In addition, genes related to rifamycin resistance were significantly enriched in fecal samples of cases with asthma, suggesting that altered resistome in gut microbiota may contribute to respiratory health in asthmatics. Further analysis of gut virulome identified differentially abundant virulence functions in asthmatic microbiome, such as enrichments for fibrinogen binding protein, magnesium uptake, and Ebp pili genes, and depletions for flagella‐mediated motility genes. Moreover, we demonstrated an inverse correlation between the abundance of Galactobacillus timonensis and serum IgE levels of the host. Our dual‐omics analyses reveal several microbial gene functions and species‐level clades derived from gut dysbiosis in robust associations with fecal metabolites and disease phenotypes, which may be of etiological and diagnostic implications in childhood airway allergies.

Role of interleukins 12B and 17A genetic variation in house dust mites allergy

BackgroundThe house dust mites (HDM) constitute a major cause of allergic diseases all over the world. Genes encoding interleukins 12B and 17A which determine the course of T cell-mediated immune response are prime candidates as allergic disease susceptibility. The purpose of this study was to evaluate whether a single-nucleotide polymorphisms (SNP) of interleukins 12B + 1188A/C (rs3212227) and 17A −197G/A (rs2275913) confers susceptibility to HDM allergic diseases. Through a case-control study, 120 subjects served as 60 dust mites' allergic patients and 60 healthy non-allergic controls. Total immunoglobulin (Ig) E level, eosinophilic count, serum interleukins 4, 10, 12B, and 17A levels for the studied subjects were measured. Then, genotyping of single-nucleotide polymorphisms (SNPs) at +1188A/C for IL12B and −197G/A for IL17A gene were conducted using restriction fragment length polymorphisms (RFLP-PCR).ResultsThe present study showed that in HDMs' allergic subjects there was a significant increase in IL12B (+1188 A/C) and IL17A (−197 G/A) genotype variants compared to that of the controls. There was a significant increase in total IgE levels, eosinophil counts, and the levels of both IL-4 and IL-17A, while IL12B was significantly lower in patients compared to that of the controls. There was no significant difference in IL-10 levels between patients and controls. ConclusionOur findings indicate that IL12B (+1188 A/C) and IL17A (−197G/A) might be associated with an increase in the susceptibility to dust mites’ allergic patients.

Microbial signature in IgE-mediated food allergies

BackgroundMultiple studies suggest a key role for gut microbiota in IgE-mediated food allergy (FA) development, but to date, none has studied it in the persistent state.MethodsTo characterize the gut microbiota composition and short-chain fatty acid (SCFAs) profiles associated with major food allergy groups, we recruited 233 patients with FA including milk (N = 66), sesame (N = 38), peanut (N = 71), and tree nuts (N = 58), and non-allergic controls (N = 58). DNA was isolated from fecal samples, and 16S rRNA gene sequences were analyzed. SCFAs in stool were analyzed from patients with a single allergy (N = 84) and controls (N = 31).ResultsThe gut microbiota composition of allergic patients was significantly different compared to age-matched controls both in α-diversity and β-diversity. Distinct microbial signatures were noted for FA to different foods. Prevotella copri (P. copri) was the most overrepresented species in non-allergic controls. SCFAs levels were significantly higher in the non-allergic compared to the FA groups, whereas P. copri significantly correlated with all three SCFAs. We used these microbial differences to distinguish between FA patients and non-allergic healthy controls with an area under the curve of 0.90, and for the classification of FA patients according to their FA types using a supervised learning algorithm. Bacteroides and P. copri were identified as taxa potentially contributing to KEGG acetate-related pathways enriched in non-allergic compared to FA. In addition, overall pathway dissimilarities were found among different FAs.ConclusionsOur results demonstrate a link between IgE-mediated FA and the composition and metabolic activity of the gut microbiota.

Hyper-Inflammatory Monocyte Activation Following Endotoxin Exposure in Food Allergic Infants.

Several recent studies have reported a key role for innate cell hyper-responsiveness in food allergy. This has predominantly been observed in early life, with evidence that innate immune function may return to baseline if food allergy resolves in later childhood. Hallmarks of hyper-responsiveness include increased circulating frequency of monocytes and altered innate cell cytokine responses to in vitro exposure with bacterial endotoxin. These features mirror the defining signatures of trained innate immunity, seen in other complex diseases. In this study, detailed immune cell and cytokine profiling was performed on peripheral blood mononuclear cells at baseline from 27 1 year old infants in the HealthNuts cohort (n = 16 egg allergic and n = 11 non-allergic healthy controls) and following monocyte stimulation. We show that egg allergic infants have increased frequency of circulating monocytes, reduced numbers of regulatory CD4 T cells and increased monocyte: CD4 T cell ratios relative to healthy controls. Monocytes from both egg allergic and non-allergic infants responded to endotoxin stimulation with rapid cytokine production and downregulation of the surface receptor CD16, however monocytes from egg allergic infants were hyper-responsive, producing significantly more inflammatory cytokines (TNFα, IL-6, IL-1β, IL-8) and innate cell recruiting factors (MIP-1α) than healthy controls. This work indicates that monocytes of food allergic infants are programmed to a hyper-inflammatory phenotype and that the development of food allergy may be associated with trained immunity in early life.

Human TH1 and TH2 cells targeting rhinovirus and allergen coordinately promote allergic asthma

Allergic asthmatic subjects are uniquely susceptible to acute wheezing episodes provoked by rhinovirus. However, the underlying immune mechanisms and interaction between rhinovirus and allergy remain enigmatic, and current paradigms are controversial. We sought to perform a comprehensive analysis of type 1 and type 2 innate and adaptive responses in allergic asthmatic subjects infected with rhinovirus. Circulating virus-specific TH1 cells and allergen-specific TH2 cells were precisely monitored before and after rhinovirus challenge in allergic asthmatic subjects (total IgE, 133-4692 IU/mL; n= 28) and healthy nonallergic controls (n= 12) using peptide/MHCII tetramers. T cells were sampled for up to 11 weeks to capture steady-state and postinfection phases. T-cell responses were analyzed in parallel with 18 cytokines in the nose, upper and lower airway symptoms, and lung function. The influence of invivo IgE blockade was also examined. In uninfected asthmatic subjects, higher numbers of circulating virus-specific PD-1+ TH1 cells, but not allergen-specific TH2 cells, were linked to worse lung function. Rhinovirus infection induced an amplified antiviral TH1 response in asthmatic subjects versus controls, with synchronized allergen-specific TH2 expansion, and production of type 1 and 2 cytokines in the nose. In contrast, TH2 responses were absent in infected asthmatic subjects who had normal lung function, and in those receiving anti-IgE. Across all subjects, early induction of a minimal set of nasal cytokines that discriminated high responders (G-CSF, IFN-γ, TNF-α) correlated with both egress of circulating virus-specific TH1 cells and worse symptoms. Rhinovirus induces robust TH1 responses in allergic asthmatic subjects that may promote disease, even after the infection resolves.

Allergic rhinitis is associated with complex alterations in high-density lipoprotein composition and function

Despite strong evidence that high-density lipoproteins (HDLs) modulate the immune response, the role of HDL in allergies is still poorly understood. Many patients with allergic rhinitis (AR) develop a late-phase response, characterized by infiltration of monocytes and eosinophils into the nasal submucosa. Functional impairment of HDL in AR-patients may insufficiently suppress inflammation and cell infiltration, but the effect of AR on the composition and function of HDL is not understood. We used apolipoprotein (apo) B-depleted serum as well as isolated HDL from AR-patients (n = 43) and non-allergic healthy controls (n = 20) for detailed compositional and functional characterization of HDL. Both AR-HDL and apoB-depleted serum of AR-patients showed decreased anti-oxidative capacity and impaired ability to suppress monocyte nuclear factor-κB expression and pro-inflammatory cytokine secretion, such as interleukin (IL)-4, IL-6, IL-8, tumor necrosis factor alpha and IL-1 beta. Sera of AR-patients showed decreased paraoxonase and cholesteryl-ester transfer protein activities, increased lipoprotein-associated phospholipase A2 activity, while lecithin-cholesterol acyltransferase activity and cholesterol efflux capacity were not altered. Surprisingly, apoB-depleted serum and HDL from AR-patients showed an increased ability to suppress eosinophil effector responses upon eotaxin-2/CCL24 stimulation. Mass spectrometry and biochemical analyses showed reduced levels of apoA-I and phosphatidylcholine, but increased levels of apoA-II, triglycerides and lyso-phosphatidylcholine in AR-HDL. The changes in AR-HDL composition were associated with altered functional properties. In conclusion, AR alters HDL composition linked to decreased anti-oxidative and anti-inflammatory properties but improves the ability of HDL to suppress eosinophil effector responses.

CD14 promotor polymorphisms associated with different allergic phenotypes and modulated with house dust mite allergy

Background: House dust mite (HDM) constitutes a major cause of allergic disease all over the world; meanwhile interaction between genetic control, environmental factors in the context of allergen exposure may affect allergic phenotype. Cluster of Differentiation 14 (CD14) polymorphisms play a major role in genetic control of allergic phenotype.Objective: We aimed to assess the role of CD14 genetic polymorphisms at two loci A(-1,145)G, and G(-1,359)T in expression of atopic asthma and allergic rhinitis in the context of HDM exposure in Jazan, KSA.Subjects and Methods: Through a case control study, 160 subjects served as 60 atopic asthmatic patients, 40 allergic rhinitis patients and 60 healthy non-allergic controls. Clinical and immunological parameters for the studied subjects were assessed. Then, genotyping of two single nucleotide polymorphisms (SNPs) at A(-1,145)G, and G(-1,359)T, in the promoter region of the CD14 gene was conducted using restriction fragment length polymorphisms (RFLP-PCR).Results: The present study showed that in HDM sensitive subjects there was a significant association between GG genotype variant at A(-1,145)G with atopic asthma patients and another significant association between TT genotype variant at G(-1,359)T with allergic rhinitis patients.Conclusion: The impact of allergy induced by HDMs may be enhanced in individuals with specific CD14 gene variants resulting in exaggerated allergic phenotype.

The Role of the Level of Interleukin-33 in the Therapeutic Outcomes of Immunotherapy in Patients with Allergic Rhinitis.

Introduction Allergic rhinitis (AR) affects up to 40% of the population and results in nasal itching, congestion, sneezing, and clear rhinorrhea. Objectives This study aimed to evaluate the changes in the clinical symptoms and in the level of serum interleukin (IL)-33 before and after pollen immunotherapy (IT) in patients with AR. Methods The total symptom score and the levels of total immunoglobulin E (IgE) and IL-33 were determined in the serum of 10 non-allergic healthy controls and 45 patients with AR who were equally divided into 3 groups: GI (patients did not receive IT), GII (patients had received IT for 6 months) and GIII (patients had received IT for 2 years). Results There was a significantly higher concentration of IgE and IL-33 in the serum of patients with AR than in that of non-allergic patients. Furthermore, serum level of IL-33 decreased significantly after pollen IT. But, there was no significant reduction in the serum level of IL-33 between GII and GIII patients. Conclusion Our results show a clinical improvement associated with a decrease in serum level of IL-33 after pollen IT.

Allergen-specific immunotherapy modulates the balance of circulating Tfh and Tfr cells

Abstract Follicular helper T cells (Tfh cells) are a CD4 T cell subset essential for germinal center formation and B cell responses, although their role in allergy and allergen-specific immunotherapy (AIT) is unclear. Here, we show that AIT-treated patients have a higher ratio of regulatory Tfh cells (Tfr) to follicular T cells (Tfh) and hypothesize an IL-2 dependent mechanism.

Memory and multitasking performance during acute allergic inflammation in seasonal allergic rhinitis.

In previous research, patients with seasonal allergic rhinitis (SAR) showed poorer school and work performance during periods of acute allergic inflammation, supporting the idea of an impact of SAR on cognitive functions. However, the specific cognitive domains particularly vulnerable to inflammatory processes are unclear. In this study, the influence of SAR on memory and multitasking performance, as two potentially vulnerable cognitive domains essential in everyday life functioning, was investigated in patients with SAR. Non-medicated patients with SAR (n = 41) and healthy non-allergic controls (n = 42) performed a dual-task paradigm and a verbal learning and memory test during and out of symptomatic allergy periods (pollen vs. non-pollen season). Disease-related factors (e.g. symptom severity, duration of symptoms, duration of disease) and allergy-related quality of life were evaluated as potential influences of cognitive performance. During the symptomatic allergy period, patients showed (1) poorer performance in word list-based learning (P = 0.028) and (2) a general slowing in processing speed (P < 0.001) and a shift in processing strategy (P < 0.001) in multitasking. Yet, typical parameters indicating specific multitasking costs were not affected. A significant negative association was found between learning performance and duration of disease (r = -0.451, P = 0.004), whereas symptom severity (r = 0.326; P = 0.037) and quality of life (r = 0.379; P = 0.015) were positively associated with multitasking strategy. Our findings suggest that SAR has a differentiated and complex impact on cognitive functions, which should be considered in the management of SAR symptoms. They also call attention to the importance of selecting sensitive measures and carefully interpreting cognitive outcomes.

Mycobacterium avium Subsp. paratuberculosis Induces Specific IgE Production in Japanese People with Allergies.

Background. The prevalence of allergies is steadily increasing worldwide; however, the pathogenesis is still unclear. We hypothesized that Mycobacterium avium subsp. paratuberculosis (MAP) may contribute to allergy development. This organism can be present in dairy foods, it can elicit an immunomodulatory switch from a Th1 to a Th2 response, and it has been speculated that it is linked to several human autoimmune diseases. To determine the contribution, sera from 99 individuals with various atopic disorders and 45 healthy nonallergic controls were assessed for total IgE levels and successively for MAP-specific IgE by ELISA. Results. The mean total serum IgE level in allergic patients was 256 ± 235 IU/mL, and in the healthy controls it was 62 ± 44 IU/mL (AUC = 0.88; p < 0.0001). Among the patient groups, 50 of the 99 subjects had increased IgE total level ≥ 150 IU/mL, while 49 subjects had IgE ≤ 150 IU/mL (mean level: 407 ± 256 IU/mL versus 106 ± 16 IU/mL; p < 0.0001). Additionally, 6 out of 50 subjects (12%) with IgE ≥ 150 IU/mL and none (0%) with IgE ≤ 150 IU/mL were positive for specific MAP IgE (AUC = 0.63; p = 0.03). Conclusion. The present study revealed that MAP has the ability to induce specific IgE and might contribute to the induction of allergic inflammation in genetically predisposed individuals.

Evaluation of vascular endothelial growth factor-A and Endostatin levels in induced sputum and relationship to bronchial hyperreactivity in patients with persistent allergic rhinitis monosensitized to house dust

Studies about the pathogenesis of bronchial hyperreactivity (BHR) in patients with persistent allergic rhinitis (PAR) and its relationship with lower airway remodeling are extremely limited. This study evaluated bronchial vascular remodeling via the measurement of angiogenic factor, vascular endothelial growth factor-A (VEGF-A), and anti-angiogenic factor, Endostatin, and evaluated their relationship with BHR in patients with PAR. The study group consisted of 30 patients with PAR monosensitized to house dust mites and 14 non-allergic healthy controls. All subjects underwent induced sputum and methacholine (M) bronchial provocation tests. VEGF-A and Endostatin levels were measured by ELISA in induced sputum supernatants. The percentages of eosinophils in induced sputum were significantly increased in patients with PAR compared with healthy controls. There were no significant differences between patients with PAR and healthy controls in terms of levels of VEGF (37.9pg/ml, min-max: 5-373pg/ml vs. 24.9, min-max: 8-67pg/ml, p=0.8 respectively), Endostatin (532.5pg/ml, min-max: 150-2125pg/ml vs. 644, min-max: 223-1123pg/ml, p=0.2 respectively) and VEGF/Endostatin ratio (0.057 vs. 0.045, p=0.8 respectively). In addition, there were no significant differences between patients who are BHR positive (n=8), or negative to M (n=22) in terms of levels of VEGF, Endostatin and VEGF/Endostatin ratio and no correlations among value of PD20 to M and levels of VEGF, Endostatin and VEGF/Endostatin ratio. We conclude that VEGF-A and Endostatin did not differ between patients with PAR and healthy controls regardless of BHR to M.

Vitamin D Supplementation Modulates the Immune System and Improves Atopic Dermatitis in Children

Background: Vitamin D seems to influence the evolution of atopic dermatitis (AD) in children. Methods: We tested the vitamin D serum levels of 39 children with AD (AD group t₀) and of 20 nonallergic healthy controls (C group). AD severity was evaluated using the AD scoring system (SCORAD index). Cytokine serum levels (IL-2, IL-4, IL-6, IFN-γ, TNF-α) and atopy biomarkers were also measured. The patients were then treated with vitamin D oral supplementation of 1,000 IU/day (25 mg/day) for 3 months. We then reevaluated the vitamin D serum levels, AD severity and cytokine serum levels in all of the treated children (AD group t₁). Results: The cross-sectional analysis on patients affected by AD (AD group t₀) showed that the initial levels of all the tested cytokines except for TNF-α were higher than those of the healthy control group (C group), falling outside the normal range. After 3 months of supplementation the patients had significantly increased vitamin D levels (from 22.97 ± 8.03 to 29.41 ± 10.73 ng/ml; p = 0.01). A concomitant significant reduction of both the SCORAD index (46.13 ± 15.68 at the first visit vs. 22.57 ± 15.28 at the second visit; p < 0.001) and of all the altered cytokines (IL-2, IL-4, IL-6, IFN-γ) was also found. Conclusions: This study showed vitamin D supplementation to be an effective treatment in reducing AD severity in children through normalization of the Th1 and Th2 interleukin serum pattern.

Altered performance in attention tasks in patients with seasonal allergic rhinitis: seasonal dependency and association with disease characteristics.

Seasonal allergic rhinitis (SAR) is a chronic disease affecting about 23% of the European population with increasing prevalence rates. Beside classical symptoms (i.e., sneezing, nasal congestion), patients frequently complain about subjective impairments in cognitive functioning during periods of acute allergic inflammation. However, objective evidence for such deficits or the role of potential modulators and underlying mechanisms is limited. The present study aimed to investigate the effect of SAR on attention-related cognitive processes. In addition, relationships between attention performance, sleep and mood disturbances as well as specific disease characteristics as potential modulators of this link were explored. SAR patients (n = 41) and non-allergic healthy controls (n = 42) completed a set of attention tasks during a symptomatic allergy period and during a non-symptomatic period. Influences of sleep, mood, total immunoglobulin E (IgE) levels and individual allergy characteristics on cognitive performance were evaluated. Compared to healthy controls, SAR patients had a slower processing speed during both symptomatic and non-symptomatic allergy periods. Additionally, they showed a more flexible adjustment in attention control, which may serve as a compensatory strategy. Reduction in processing speed was positively associated with total IgE levels whereas flexible adjustment of attention was linked with anxious mood. No association was found between SAR-related attention deficits and allergy characteristics or sleep. SAR represents a state that is crucially linked to impairments in information processing and changes in attentional control adjustments. These cognitive alterations are more likely to be influenced by mood and basal inflammatory processes than sleep impairments or subjective symptom severity.

Expression of Th1, Th2, lymphocyte trafficking and activation markers on CD4+ T-cells of Hymenoptera allergic subjects and after venom immunotherapy

Systemic reactions to Hymenoptera stings can be fatal and represent a reduction in the quality of life. The immune mechanisms involved in venom allergic subjects are barely known. Nevertheless, a shift towards a Th1-type response with an increase in IFNγ levels has been observed after venom immunotherapy (VIT). There is currently no information available about the expression of markers on CD4+ T-cells or their involvement in venom allergy, nor following VIT. For this, we have studied the expression of Th1 and Th2-cell markers, homing receptors and activation markers on CD4+ T-cells of subjects who presented systemic allergic reactions, mainly to Polistes dominulus, and after receiving a 4-month conventional VIT protocol. The markers studied were: CD26 (Th1), CD30 (Th2), CXCR4, CXCR3 (Th1), CCR4 (Th2), CD154 (CD40L), CD152 (CTLA-A), and ICOS. We also determined the IL-4 (Th2) and IFNγ (Th1) intracellular cytokine levels in T-cells and carried out a basophil activation test (BAT). Comparing venom allergic subjects with non-allergic healthy controls, we have found up-regulation of CD26, CXCR4, CXCR3, CD154 and ICOS. Conversely, a down-regulation of CD30, CD154 and CD152 occurred upon immune intervention, whereas the remaining markers were not affected. Equally, VIT has been shown to be effective, as evidenced by the decrease of basophil degranulation and increase of IFNγ levels in T-cells after the fourth month of treatment. These new findings highlight the possible application of these surface molecules as markers to distinguish between symptomatic and asymptomatic subjects sensitized to Hymenoptera venom, as well as revealing information about the immune changes associated with VIT.

Evaluation of coagulation activation after Rhinovirus infection in patients with asthma and healthy control subjects: an observational study

BackgroundAsthma exacerbations are frequently triggered by rhinovirus infections. Both asthma and respiratory tract infection can activate haemostasis. Therefore we hypothesized that experimental rhinovirus-16 infection and asthmatic airway inflammation act in synergy on the haemostatic balance.Methods28 patients (14 patients with mild allergic asthma and 14 healthy non-allergic controls) were infected with low-dose rhinovirus type 16. Venous plasma and bronchoalveolar lavage fluid (BAL fluid) were obtained before and 6 days after infection to evaluate markers of coagulation activation, thrombin-antithrombin complexes, von Willebrand factor, plasmin-antiplasmin complexes, plasminogen activator inhibitor type-1, endogenous thrombin potential and tissue factor-exposing microparticles by fibrin generation test, in plasma and/or BAL fluid. Data were analysed by nonparametric tests (Wilcoxon, Mann Whitney and Spearman correlation).Results13 patients with mild asthma (6 females, 19-29 y) and 11 healthy controls (10 females, 19-31 y) had a documented Rhinovirus-16 infection. Rhinovirus-16 challenge resulted in a shortening of the fibrin generation test in BAL fluid of asthma patients (t = -1: 706 s vs. t = 6: 498 s; p = 0.02), but not of controls (t = -1: 693 s vs. t = 6: 636 s; p = 0.65). The fold change in tissue factor-exposing microparticles in BAL fluid inversely correlated with the fold changes in eosinophil cationic protein and myeloperoxidase in BAL fluid after virus infection (r = -0.517 and -0.528 resp., both p = 0.01).Rhinovirus-16 challenge led to increased plasminogen activator inhibitor type-1 levels in plasma in patients with asthma (26.0 ng/mL vs. 11.5 ng/mL in healthy controls, p = 0.04). Rhinovirus-16 load in BAL showed a linear correlation with the fold change in endogenous thrombin potential, plasmin-antiplasmin complexes and plasminogen activator inhibitor type-1.ConclusionsExperimental rhinovirus infection induces procoagulant changes in the airways of patients with asthma through increased activity of tissue factor-exposing microparticles. These microparticle-associated procoagulant changes are associated with both neutrophilic and eosinophilic inflammation. Systemic activation of haemostasis increases with Rhinoviral load.Trial registrationThis trial was registered at the Dutch trial registry (http://www.trialregister.nl): NTR1677.

79. Mood and cognitive disturbances in seasonal allergic rhinitis: Association with parameters of disease and inflammation

Patients with seasonal allergic rhinitis (SAR) frequently complain about declines in mood and cognitive performance during phases of acute allergic inflammation. The underlying mechanisms leading to those impairments, however, are still a matter of debate. The present study was designed to investigate the association between altered mood and cognition in SAR patients and allergic inflammatory parameters. In SAR patients ( n = 41) and non-allergic healthy controls ( n = 42) memory and attention performances as well as self-reported depression and anxiety were evaluated during and out of a symptomatic allergy phase (e.g. pollen season). To determine the impact of disease parameters on mood and cognition, symptom severity, total-IgE levels and inflammatory cytokines (IL-6, IL-10, IL-17, IFN-gamma, TNF-alpha) were assessed. Results showed that SAR patients experience a significant increase in depression and anxiety symptomatology during pollen season. Additionally, aspects of memory and attention performance were impaired. Depressive mood and state anxiety during allergy season were significantly associated with total-IgE levels, while no association with symptom severity could be observed. Analyses of cytokine data are currently under way and will be presented at the meeting. The present findings suggest impaired mood and cognition in patients suffering from acute SAR which may be linked rather to immunological (inflammatory) processes than to SAR symptomatology.

Tolerant beekeepers display venom-specific functional IgG4 antibodies in the absence of specific IgE

Tolerant beekeepers display venom-specific functional IgG4 antibodies in the absence of specific IgE

T-cell and antibody responses to phospholipase A2 from different species show distinct cross-reactivity patterns

Secreted phospholipases A2 (sPLA2) represent antigens to which humans may be rarely or frequently exposed. Thus, the investigation of humoral and cellular immune responses to sPLA2s from different species can provide a suitable model in the study of antibody and T-cell cross-reactivity. Specific IgE, IgG1, IgG4, and IgA antibodies were analyzed by ELISA against sPLA2s from pancreas of Bos taurus (BT), Apis mellifera (AM) bee venom, Daboia russellii (DR) and Naja mossambica (NM) snake venoms, and human group III (hGIII) sPLA2 using sera of nonallergic beekeepers, AM-allergic patients, and healthy controls. T-cell cross-reactivity was investigated in PBMC, and T-cell clones (TCC) are generated against AM sPLA2. Hyperimmune and allergic individuals showed high levels of sPLA2-specific IgG4 and significant IgG4 cross-reactivity between BT, DR, and NM sPLA2s. Furthermore, IgE, IgA, and IgG1 cross-reactivities against BT, DR, and NM sPLA2s were also detectable in the range of 22.2-44.8%. Allergic patients showed significant T-cell proliferative response to NM sPLA2 together with increased IFN-γ and IL-13 production even though they had never been exposed to cobra venom. Although nonallergic healthy controls show no cross-reactivity at T-cell level, they did have low levels of IgG4 and IgA against BT, DR, and NM sPLA2s. Human TCC spanning three major T-cell epitopes of AM sPLA2 showed minor proliferative response to NM and hGIII sPLA2s. This study shows that T cells and antibodies may show cross-reactivity between different species without being naturally exposed to sPLA2s.