The Journal of allergy and clinical immunology
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J. Allergy Clin. Immunol. · Jul 2010
Randomized Controlled Trial Multicenter StudySerum vitamin D levels and severe asthma exacerbations in the Childhood Asthma Management Program study.
Asthma exacerbations, most often caused by respiratory tract infections, are the leading causes of asthma morbidity and comprise a significant proportion of asthma-related costs. Vitamin D status might play a role in preventing asthma exacerbations. ⋯ Vitamin D insufficiency is common in this population of North American children with mild-to-moderate persistent asthma and is associated with higher odds of severe exacerbation over a 4-year period.
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J. Allergy Clin. Immunol. · Jul 2010
ReviewPractical approach to the patient with hypereosinophilia.
Markedly increased blood eosinophilia (ie, > or =1.5 x 10(9)/L), whether discovered fortuitously or found with signs and symptoms of associated organ involvement, commands diagnostic evaluation and often therapeutic interventions. This degree of hypereosinophilia is often but not uniformly associated with eosinophilic infiltration of tissues that can potentially lead to irreversible, life-threatening organ damage. ⋯ If evaluations exclude eosinophilia attributable to secondary causes or other eosinophil-related syndromes or organ-specific diseases, attention must be directed to considerations of varied other forms of the hypereosinophilic syndromes, which include myeloproliferative variants, lymphocytic variants, and many of still unknown causes. Cognizant of the capacities of eosinophils to mediate tissue damage, the varied causes for hypereosinophilia are considered, and a contemporary stepwise practical approach to the diagnosis and treatment of patients with hypereosinophilia is presented.
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Epidemiologic associations between viral lower respiratory infections (LRIs) and asthma in later childhood are well known. However, the question of whether such infections cause asthma or unmask asthma in a susceptible host has still not been settled. Most early evidence centered on the role of the respiratory syncytial virus; however, recent studies highlight a potential role for human rhinovirus as a risk factor for asthma. ⋯ The risk of asthma after viral LRI is increased in the presence of allergic sensitization in early life and if the infection is more severe. Atopy-associated mechanisms also appear to be involved in viral-induced acute exacerbations of asthma, especially in prolonging symptomatology after the virus has been cleared from the lungs. Breaking the nexus between viral respiratory infections and asthma may be possible with interventions designed to inhibit atopy-related effectors mechanisms from participating in the host response to respiratory viral infections.