clair088

Despite the improvement of air quality in the U.S. since the enhancement of the Clean Air Act in 1990, exposures to outdoor and indoor air pollution remain a significant risk factor for both the development of asthma and the triggering of asthma symptoms.   Clinical studies have shown that significant asthma exacerbations were attributable to air pollution exposure, as a result of living in densely populated cities with elevated ambient fine particulate matter (PM 2.5 ) and ozone (O 3 ). In their review, Miller and Peden highlight new data on the effects of pollutant exposure on the innate and adaptive immune responses, genetic and epigenetic modifiers of response to pollutants, and potential interventions to mitigate these effects ( J Allergy Clin Immunol 2014; 134(5): 1001-1008 ). Several studies have determined that the effects of air pollution are heightened during the prenatal period.  This suggests that there is greater vulnerability of the growing lungs and the dev...

In the U.S., ethnic minorities and the economically disadvantaged are disproportionately exposed to chronic psychological stressors such as poverty, discrimination and violence. Recent findings support a causal link between exposure to these stressors at the individual or community level and asthma morbidity. Moreover, current evidence suggests that the relation between stress and asthma is complex and partially mediated or modified by environmental exposures, adherence with treatment, co-morbidities and coping mechanisms. In a review article, Rosenberg et al discuss recent findings suggesting potential biologic mechanisms for stress-related asthma, including changes in the methylation and expression of genes that regulate behavioral, autonomic, neuroendocrine, and immunologic responses to stress ( J Allergy Clin Immunol 2014; 134(5): 1009-1015 ). For example, there may be susceptibility genes that predispose chronically stressed youth to both post-traumatic stress disorder and asthma....

In the October 2014 issue of Journal of Allergy and Clinical Immunology, Brough et al show that early environmental peanut exposure from house dust increases the risk of peanut allergy in children with impaired skin barrier. Children were assessed for peanut allergy and had genetic studies to determine whether they could produce normal filaggrin levels. Dust samples were collected and analyzed for peanut concentration to determine in which groups of children environmental peanut exposure influenced the development of peanut allergy. In normal children environmental peanut exposure did not influence the development of peanut allergy. In contrast, in filaggrin deficient children the risk of peanut allergy increased as peanut concentration in the house dust increased. To read the full article, please click here: http://bit.ly/1qkfHeY

Atopic eczema (AE, syn. atopic dermatitis) is a major medical condition that causes substantial burden to patients, their families, and society. Various different interventions exist, many of which have been assessed in randomized controlled trials (RCTs). However, there is a lack of core outcome sets for atopic eczema (AE) which is a major obstacle for advancing evidence-based treatment.  There are several different instruments identified to assess clinical signs of AE and the global Harmonizing Outcome Measures for Eczema (HOME) initiative has already defined clinical signs, symptoms, quality of life, and long-term control of flares as core outcome domains for AE-trials. To resolve the current lack of standardization of the assessment of clinical signs of AE, the HOME initiative followed a structured process of systematic reviews and international consensus sessions to identify one core outcome measurement instrument to assess clinical signs in all future AE-trials...

Atopic dermatitis (AD) is the most common chronic inflammatory skin disease and often precedes the development of food allergy and asthma.  The defective skin barrier in AD is thought to allow the absorption of allergens through the skin.  This promotes systemic allergen sensitization, contributing to the development of food allergy and asthma, as well as skin infections such as Staphylococcus aureus and herpes simplex virus (HSV).  This month’s JACI focuses on the importance of both genetic and acquired causes of epithelial skin barrier dysfunction in driving the natural history of AD. In their review, Donald Leung and Emma Guttman-Yassky summarize current insights into AD that may lead to new treatment approaches, including several articles published in this month’s journal ( J Allergy Clin Immunol 2014; 134(4): 769-779 ). The causes of AD are complex and driven by a combination of genetic, environmental and immunologic factors which likely account for heterogeneity of ...

Allergic sensitization to inhaled antigens is increasingly common; however, the mechanisms remain poorly understood. Lung epithelial cells, once thought to be merely a passive barrier impeding allergen penetrance, have recently been shown to recognize allergens via expression of pattern recognition receptors (PRRs) and mount an innate immune response driven by the activation of the cytokine NF-кB. In their review, Lambrecht and Hammad discuss recent findings that describe epithelial cells as crucial in allergy inhalation outcomes ( J Allergy Clin Immunol 2014; 134(3): 499-507 ). Traditionally, allergic asthma has been characterized as a disease of the adaptive immune system, whereby lymphocytes overreact to harmless antigens and mount a type 2 immune response, subsequently causing the activation of effector cells like mast cells, basophils and eosinophils. Recently, research has been changing this view to accommodate the concept that cells of the innate immune system contribute signif...

Airway epithelial cells are an important part of the innate immune system in the lung. Not only do they establish mucociliary clearance, epithelial cells produce anti-microbial peptides, chemokines, and cytokines that recruit and activate other cell types and promote pathogen clearance. Recent studies emphasize the importance of epithelial derived cytokines in the promotion of Th2 immune responses, at least in part by conditioning local dendritic cells (DCs). Epithelial cells also from a barrier to the outside world comprised of airway surface liquids, mucus, and apical junctional complexes (AJC) that form between neighboring cells. In their recent review, Georas and Rezaee discuss why defective epithelial barrier function may be linked to Th2 polarization in asthma, and propose a rheostat model of barrier dysfunction that implicates the size of inhaled allergen particles as an important factor influencing adaptive immunity ( J Allergy Clin Immunol 2014; 134(3): 509-520 ).  Increa...