815 resultados para Allergic bronchopulmonary aspergillosis


Relevância:

20.00% 20.00%

Publicador:

Resumo:

Asthma is a chronic inflammatory disorder of the airways that is coordinated by Th2 cells in both human asthmatics and animal models of allergic asthma. Migration of Th2 cells to the lung is key to their inflammatory function and is regulated in large part by chemokine receptors, members of the seven-membrane-spanning receptor family. It has been reported recently that T cells lacking β-arrestin-2, a G protein-coupled receptor regulatory protein, demonstrate impaired migration in vitro. Here we show that allergen-sensitized mice having a targeted deletion of the β-arrestin-2 gene do not accumulate T lymphocytes in their airways, nor do they demonstrate other physiological and inflammatory features characteristic of asthma. In contrast, the airway inflammatory response to LPS, an event not coordinated by Th2 cells, is fully functional in mice lacking β-arrestin-2. β-arrestin-2-deficient mice demonstrate OVA-specific IgE responses, but have defective macrophage-derived chemokine-mediated CD4+ T cell migration to the lung. This report provides the first evidence that β-arrestin-2 is required for the manifestation of allergic asthma. Because β-arrestin-2 regulates the development of allergic inflammation at a proximal step in the inflammatory cascade, novel therapies focused on this protein may prove useful in the treatment of asthma.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

PURPOSE: The role of PM10 in the development of allergic diseases remains controversial among epidemiological studies, partly due to the inability to control for spatial variations in large-scale risk factors. This study aims to investigate spatial correspondence between the level of PM10 and allergic diseases at the sub-district level in Seoul, Korea, in order to evaluate whether the impact of PM10 is observable and spatially varies across the subdistricts. METHODS: PM10 measurements at 25 monitoring stations in the city were interpolated to 424 sub-districts where annual inpatient and outpatient count data for 3 types of allergic diseases (atopic dermatitis, asthma, and allergic rhinitis) were collected. We estimated multiple ordinary least square regression models to examine the association of the PM10 level with each of the allergic diseases, controlling for various sub-district level covariates. Geographically weighted regression (GWR) models were conducted to evaluate how the impact of PM10 varies across the sub-districts. RESULTS: PM10 was found to be a significant predictor of atopic dermatitis patient count (P<0.01), with greater association when spatially interpolated at the sub-district level. No significant effect of PM10 was observed on allergic rhinitis and asthma when socioeconomic factors were controlled for. GWR models revealed spatial variation of PM10 effects on atopic dermatitis across the sub-districts in Seoul. The relationship of PM10 levels to atopic dermatitis patient counts is found to be significant only in the Gangbuk region (P<0.01), along with other covariates including average land value, poverty rate, level of education and apartment rate (P<0.01). CONCLUSIONS: Our findings imply that PM10 effects on allergic diseases might not be consistent throughout Seoul. GIS-based spatial modeling techniques could play a role in evaluating spatial variation of air pollution impacts on allergic diseases at the sub-district level, which could provide valuable guidelines for environmental and public health policymakers.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Members of the suppressor of cytokine signaling (SOCS) family are involved in the pathogenesis of many inflammatory diseases. SOCS-3 is predominantly expressed in T-helper type 2 (TH2) cells, but its role in TH2-related allergic diseases remains to be investigated. In this study we provide a strong correlation between SOCS-3 expression and the pathology of asthma and atopic dermatitis, as well as serum IgE levels in allergic human patients. SOCS-3 transgenic mice showed increased TH2 responses and multiple pathological features characteristic of asthma in an airway hypersensitivity model system. In contrast, dominant-negative mutant SOCS-3 transgenic mice, as well as mice with a heterozygous deletion of Socs3, had decreased TH2 development. These data indicate that SOCS-3 has an important role in regulating the onset and maintenance of TH2-mediated allergic immune disease, and suggest that SOCS-3 may be a new therapeutic target for the development of antiallergic drugs.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Background The Allergic Rhinitis Clinical Investigator Collaborative (AR-CIC) uses a Nasal Allergen Challenge (NAC) model to study the pathophysiology of AR and provides proof of concept for novel therapeutics. The NAC model needs to ensure optimal participant qualification, allergen challenge, clinical symptoms capture and biological samples collection. Repeatability of the protocol is key to ensuring unbiased efficacy analysis of novel therapeutics. The effect of allergen challenge on IL-33 gene expression and its relation to IL1RL1 receptor and cytokine secretion was investigated. Methods Several iterations of the NAC protocol was tested, comparing variations of qualifying criteria based on the Total Nasal Symptom Score (TNSS) and Peak Nasal Inspiratory Flow (PNIF). The lowest allergen concentration was delivered and TNSS and PNIF recorded 15 minutes later. Participants qualified if the particular criteria for the protocol were met, otherwise the next higher allergen concentration (4-fold increase), was administered until the targets were reached. Participants returned for a NAC visit and received varying allergen challenge concentrations depending on the protocol, TNSS/PNIF were recorded at 15 minutes, 30 minutes, 1 hour, and hourly up to 12 hours, a 24 hour time point was added in later iterations. Repeatability was evaluated using a 3-4week interval between screening, NAC1, and NAC2 visits. Various biomarker samples were collected. Results A combined TNSS and PNIF criterion was more successful in qualifying participants. The cumulative allergen challenge (CAC) protocol proved more reliable in producing a robust clinical and biomarker response. Repeatability of the CAC protocol was achieved with a 3-week interval between visits, on a clinical and biological basis. IL-33 cytokine is an important biomarker in initiating the inflammatory response in AR in humans. IL-33 and IL1RL1 expression might employ a negative feedback mechanism in human nasal epithelial cells. Comparing the clinical and biological response to ragweed vs cat allergen challenge, proved the CAC protocol’s suitability for use employing different allergens. Conclusion The AR-CIC’s CAC protocol is an effective method of studying AR, capable of generating measurable and repeatable clinical and biomarker responses, enabling better understanding of AR pathophysiology and ensuring that any change would be purely due to medication under investigation in a clinical trial setting.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Allergic asthma is a complex immunologically mediated disease associated with increased oxidative stress and altered antioxidant defenses. It was hypothesized that a-tocopherol (a-T) decreases oxidative stress and therefore its absence may influence allergic inflammatory process, a pathobiology known to be accompanied by oxidative stress. Therefore, selected parameters of allergic asthma sensitization and inflammation were evaluated following ovalbumin sensitization and re-challenge of a-T transfer protein (TTP) knock-out mice (TTP-/-) that have greatly reduced lung a-T levels (e.g.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2899803/

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Asthma is a major risk cofactor for anaphylactic deaths in children with peanut allergy. Peanut allergy is generally thought to be a lifelong condition, but some children outgrow their coexistent asthma. It has recently been shown that children who have ‘outgrown’ their asthma symptoms may have ongoing eosinophilic airways inflammation. The need for regular inhaled corticosteroid treatment in peanut allergic children and adolescents who have outgrown their asthma is however unclear. The aims of our study were to look at fractional exhaled nitric oxide levels (FeNO), as a non-invasive marker of eosinophilic airways inflammation, in peanut allergic children and assess whether children with outgrown asthma had elevated levels. Children with peanut allergy were recruited at two pediatric allergy clinics in Belfast, UK. Exhaled nitric oxide levels (FeNO) were measured using the Niox Mino in all children. Of the 101 peanut allergic children who consented for enrolment in the study, 94 were successfully able to use the NIOX Mino. Age range was 4–15 yr (median 10 yr); 61% were boys. Thirty (32%) had never wheezed, 37 (39%) had current treated asthma, 20 (21%) had at least 1 wheezing episode within the last year but were not taking any regular asthma medication (wheeze no treatment), and 7 (7%) had outgrown asthma. All children with outgrown asthma had elevated levels of FeNO (>35 ppb), and 75% of children defined as ‘wheeze no treatment’ had elevated FeNO levels (>35 ppb). Outgrown asthma and children defined as ‘wheeze no treatment’ had higher levels of FeNO than those with no history of wheeze or current treated asthma (p = 0.003). In children with peanut allergy, we found that those who had outgrown asthma had elevated FeNO levels in keeping with ongoing eosinophilic airways inflammation.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The incidence of allergy and asthma in developed countries is on the increase and this trend looks likely to continue. CD4(+) T helper 2 (Th2) cells are major drivers of these diseases and their commitment is controlled by cytokines such as interleukin 4, which are in turn regulated by the suppressor of cytokine signaling (SOCS) proteins. We report that SOCS2(-/-) CD4(+) T cells show markedly enhanced Th2 differentiation. SOCS2(-/-) mice, as well as RAG1(-/-) mice transferred with SOCS2(-/-) CD4(+) T cells, exhibit elevated type 2 responses after helminth antigen challenge. Moreover, in in vivo models of atopic dermatitis and allergen-induced airway inflammation, SOCS2(-/-) mice show significantly elevated IgE, eosinophilia, type 2 responses, and inflammatory pathology relative to wild-type mice. Finally, after T cell activation, markedly enhanced STAT6 and STAT5 phosphorylation is observed in SOCS2(-/-) T cells, whereas STAT3 phosphorylation is blunted. Thus, we provide the first evidence that SOCS2 plays an important role in regulating Th2 cell expansion and development of the type 2 allergic responses.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

We have shown that proteinase-activated receptor-2 (PAR(2)) activation in the airways leads to allergic sensitization to concomitantly inhaled Ags, thus implicating PAR(2) in the pathogenesis of asthma. Many aeroallergens with proteinase activity activate PAR(2). To study the role of PAR(2) in allergic sensitization to aeroallergens, we developed a murine model of mucosal sensitization to cockroach proteins. We hypothesized that PAR(2) activation in the airways by natural allergens with serine proteinase activity plays an important role in allergic sensitization. Cockroach extract (CE) was administered to BALB/c mice intranasally on five consecutive days (sensitization phase) and a week later for four more days (challenge phase). Airway hyperresponsiveness (AHR) and allergic airway inflammation were assessed after the last challenge. To study the role of PAR(2), mice were exposed intranasally to a receptor-blocking anti-PAR(2) Ab before each administration of CE during the sensitization phase. Mucosal exposure to CE induced eosinophilic airway inflammation, AHR, and cockroach-specific IgG1. Heat-inactivated or soybean trypsin inhibitor-treated CE failed to induce these effects, indicating that proteinase activity plays an important role. The use of an anti-PAR(2) blocking Ab during the sensitization phase completely inhibited airway inflammation and also decreased AHR and the production of cockroach-specific IgG1. PAR(2) activation by CE acts as an adjuvant for allergic sensitization even in the absence of functional TLR4. We conclude that CE induces PAR(2)-dependent allergic airway sensitization in a mouse model of allergic airway inflammation. PAR(2) activation may be a general mechanism used by aeroallergens to induce allergic sensitization. The Journal of Immunology, 2011, 186: 3164-3172.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Background: The purpose of this systematic literature review was to examine current empirical research on general and respiratory health outcomes in adult survivors of bronchopulmonary dysplasia (BPD).

Methods: We searched seven databases up to the end of November 2010 (MEDLINE, PubMed, EMBASE, PsycINFO, Maternity and Infant Care, Cumulative Index of Nursing and Allied Health Literature, and Web of Knowledge). We independently screened and included only those studies concerning the assessment of outcome measures in adult survivors of BPD. Data on methodologic design and findings were extracted from each included study; in addition, the methodologic quality of each study was assessed using the Critical Appraisal Skills Programme checklist.

Results: Fourteen cohort studies met the review criteria. Of those, a total of eight studies were considered to be of high quality (score 9-12), five of moderate quality (score 5-8), and only one was of low quality (score 0-4). In all studies of adult survivors of BPD, differences were found between the index and control groups, suggesting that many adults survivors of BPD who were born preterm or with very low birth weight had more respiratory symptoms and pulmonary function abnormalities compared with their peers. Five studies concerning radiologic findings reported structural changes persisting into adulthood. Findings from three studies suggested impairment in exercise capacity, although firm conclusions were limited by the small sample size in the studies reviewed.

Conclusions: Compared with adults born at term, adult survivors of BPD have more impairment in general and respiratory health, which does not seem to diminish over time.