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Development and validation of a novel risk score for asthma exacerbations: The risk score for exacerbations

Asthma management involves achieving and maintaining current asthma control and preventing exacerbations. Reports have shown, however, that there can be a disassociation between these two goals, meaning control may be achieved but risk of exacerbations may remain, or the opposite. The identification of patients at risk of future severe exacerbations, whose asthma might be less treatment-responsive, or both could focus treatment selection. To this end, Bateman et al have developed a simple risk score for exacerbations (RSE) for clinical use ( J Allergy Clin Immunol 2015; 135(6): 1457-64 ). The authors analyzed a large data set of patients enrolled in studies comparing the efficacy of budesonide-formoterol (BUD/FORM) maintenance and reliever therapy with fixed-dose inhaled corticosteroid/long-acting β 2 -agonist (ICS/LABA) therapy. They included patients whose symptoms were not controlled on Global Initiative for Asthma (GINA) treatment steps 3 and 4 and who had experienced 1 or more ex...

Platelets in the immune response: Revisiting platelet-activating factor in anaphylaxis

Platelet-activating factor (PAF) is a potent phospholipid-derived mediator thought to play a pivotal role in the etiology of numerous immune and inflammatory conditions. Our knowledge of its effects has broadened to include those as a vasodilator and broncho-constrictor, a contributor to host defenses, and a mediatory of the inflammatory response, and PAF has been well-demonstrated in experimental models to function as a central mediator of anaphylaxis. Gill et al review what we know ( J Allergy Clin Immunol 2015; 135(6): 1424-32 ). PAF is produced and secreted by several types of cells including mast cells, monocytes, tissue macrophages, eosinophils, endothelial cells, neutrophils, and platelets. It is implicated in platelet aggregation and activation through release of vasoactive amines in the inflammatory response, resulting in effects including increased vascular permeability, circulatory collapse, and decreased cardiac output. Studies have shown patients with acute allergic react...

The role of platelets in allergic airway inflammation

Platelets are anucleated blood elements involved in hemostasis and thrombosis. It is now understood that they can also act as inflammatory cells and contribute to host defense against infection, performing many functions normally associated with leukocytes. Studies have shown that platelet depletion compromises ability to resist microorganism infection. Given that many inflammatory diseases are the result of inappropriate activation of defense pathways, it is likely inappropriate platelet activation contributes to the pathogenesis of these diseases. Idzko et al present the currently available data investigating the role of platelets in allergic airway inflammation and asthma ( J Allergy Clin Immunol 2015; 135(6): 1416-23 ). Of particular relevance to allergic inflammation, it has been shown that platelets express IgE receptors on their surfaces. They play an essential role in killing certain parasites, and platelet activation has been shown to accompany allergen exposure of sensitized...

Platelets in aspirin-exacerbated respiratory disease

Aspirin-exacerbated respiratory disease (AERD) is an acquired syndrome that is irreversible and debilitating. A chronic inflammatory disease characterized by the triad of asthma, nasal polyposis, and pathognomonic respiratory reactions after the ingestion of aspirin, it presents with an onset in young adulthood. Estimations indicate there are approximately 1.2 million adults in the United States living with AERD. Its pathogenesis likely involves disturbances in the mechanisms that regulate tissue recruitment of immune effector cells and activity of the 5-LO/LTC 4 S pathway. There is substantial evidence that platelets contribute to these mechanisms. Laidlaw et al review the evidence regarding asthma in general and AERD in particular ( J Allergy Clin Immunol 2015; 135(6): 1407-14 ). Platelets lack a nucleus and have no DNA. They are derived from cytoplasmic fragments of megakaryocytes and have a life span in the circulation of approximately 8-10 days before being removed by the spleen....

Celiac Disease

Given an increasing awareness of gluten-related disorders, medical professionals are encountering patients diagnosed with celiac disease or thought to have food intolerance to gluten. Green et al provide a review of the pathogenesis, clinical manifestations, diagnosis, and management of celiac disease ( J Allergy Clin Immunol 2015; 135(5):1099-1106 ). There are currently three major wheat-related food illnesses: celiac disease (CD), non-celiac gluten sensitivity (NCGS), and wheat allergy. CD is an autoimmune disorder involving both an innate and adaptive response in genetically predisposed individuals. Unlike food allergies, the pathogenesis of CD is not mediated by an immediate hypersensitivity reaction via an immunoglobulin (IgE) dependent mechanism. Instead, gluten protein is a pathogenic agent activated by the enzyme tissue transglutaminase (TTG) allowing its presentation to CD4+ T cells in the small intestine. NCGS is a term that refers to a spectrum of clinical phenotypes, witho...

Immunopathophysiology of food protein-induced enterocolitis syndrome

Food protein-induced enterocolitis syndrome (FPIES) and food protein-induced proctocolitis are non-IgE-mediated gastrointestinal allergies. Our current understanding of the mechanisms of these allergies linking exposure to the typical symptoms of vomiting, hypotension, and diarrhea falls behind that of other food-induced allergic disorders. Accompanying a comprehensive review of clinical features by Nowak-Wegrzyn that also appears in this issue, Berin assesses the state of our knowledge of the immune mechanisms of FPIES ( J Allergy Clin Immunol 2015; 135(5):1108-1113 ). FPIES is most commonly triggered by the protein component in cow’s milk, but a host of other foods can be triggers as well. Many of the foods that trigger FPIES reactions are also IgE-mediated food allergens, such as soy, fish, wheat, and egg, but many are not common in that regard. For example, rice is the third most common cause of FPIES in US cohorts, followed by oats. The fact that a range of common foods have the p...

Anaphylaxis: Unique aspects of clinical diagnosis and management in infants (birth to age 2 years)

Anaphylaxis is reported to occur with increasing frequency in infants. An illustrated Rostrum on the diagnosis, treatment, and long-term management of anaphylaxis in this age group has been published by Simons and Sampson ( J Allergy Clin Immunol 2015;135: 1125-31 ). Foods such as milk, egg, and peanut are by far the most common triggers of anaphylaxis in infancy, although medications and other triggers can also be implicated. Infants with anaphylaxis typically present with sudden onset of skin signs such as generalized urticaria, respiratory symptoms such as cough, wheeze, stridor, and dyspnea, and/or gastrointestinal symptoms such as persistent vomiting. Clinical criteria for diagnosis of anaphylaxis are validated for use in children and adults, but have not yet been validated for use in infants. A high index of suspicion is required to diagnose anaphylaxis in babies, as they cannot describe symptoms such as itching, and signs of infant anaphylaxis such as flushing, dysphonia, incont...