Respiratory Infections Precede Adult-Onset Asthma

BACKGROUND: Respiratory infections in early life are associated with an increased risk of developing asthma but there is little evidence on the role of infections for onset of asthma in adults. The objective of this study was to assess the relation of the occurrence of respiratory infections in the past 12 months to adult-onset asthma in a population-based incident case-control study of adults 21-63 years of age. METHODS/PRINCIPAL FINDINGS: We recruited all new clinically diagnosed cases of asthma (n = 521) during a 2.5-year study period and randomly selected controls (n = 932) in a geographically defined area in South Finland. Information on respiratory infections was collected by a self-administered questionnaire. The diagnosis of asthma was based on symptoms and reversible airflow obstruction in lung function measurements. The risk of asthma onset was strongly increased in subjects who had experienced in the preceding 12 months lower respiratory tract infections (including acute bronchitis and pneumonia) with an adjusted odds ratio (OR) 7.18 (95% confidence interval [CI] 5.16-9.99), or upper respiratory tract infections (including common cold, sinusitis, tonsillitis, and otitis media) with an adjusted OR 2.26 (95% CI 1.72-2.97). Individuals with personal atopy and/or parental atopy were more susceptible to the effects of respiratory infections on asthma onset than non-atopic persons. CONCLUSIONS/SIGNIFICANCE: This study provides new evidence that recently experienced respiratory infections are a strong determinant for adult-onset asthma. Reducing such infections might prevent onset of asthma in adulthood, especially in individuals with atopy or hereditary propensity to it

Lower Respiratory Tract Infection Induced by a Genetically Modified Picornavirus in Its Natural Murine Host

Infections with the picornavirus, human rhinovirus (HRV), are a major cause of wheezing illnesses and asthma exacerbations. In developing a murine model of picornaviral airway infection, we noted the absence of murine rhinoviruses and that mice are not natural hosts for HRV. The picornavirus, mengovirus, induces lethal systemic infections in its natural murine hosts, but small genetic differences can profoundly affect picornaviral tropism and virulence. We demonstrate that inhalation of a genetically attenuated mengovirus, vMC0, induces lower respiratory tract infections in mice. After intranasal vMC0 inoculation, lung viral titers increased, peaking at 24 h postinoculation with viral shedding persisting for 5 days, whereas HRV-A01a lung viral titers decreased and were undetectable 24 h after intranasal inoculation. Inhalation of vMC0, but not vehicle or UV-inactivated vMC0, induced an acute respiratory illness, with body weight loss and lower airway inflammation, characterized by increased numbers of airway neutrophils and lymphocytes and elevated pulmonary expression of neutrophil chemoattractant CXCR2 ligands (CXCL1, CXCL2, CXCL5) and interleukin-17A. Mice inoculated with vMC0, compared with those inoculated with vehicle or UV-inactivated vMC0, exhibited increased pulmonary expression of interferon (IFN-α, IFN-β, IFN-λ), viral RNA sensors [toll-like receptor (TLR)3, TLR7, nucleotide-binding oligomerization domain containing 2 (NOD2)], and chemokines associated with HRV infection in humans (CXCL10, CCL2). Inhalation of vMC0, but not vehicle or UV-inactivated vMC0, was accompanied by increased airway fluid myeloperoxidase levels, an indicator of neutrophil activation, increased MUC5B gene expression, and lung edema, a sign of infection-related lung injury. Consistent with experimental HRV inoculations of nonallergic, nonasthmatic human subjects, there were no effects on airway hyperresponsiveness after inhalation of vMC0 by healthy mice. This novel murine model of picornaviral airway infection and inflammation should be useful for defining mechanisms of HRV pathogenesis in humans

Bronchial provocation with cat allergen: correlation between the individual IgE-CRIE pattern and the occurrence of a late allergic reaction

Twenty-one mild asthmatic patients allergic to cat dander underwent a bronchial provocation test (BPT) with a cat extract. An early allergic response (EAR) was observed in all 21 patients and a late allergic response (LAR) in 8/21 patients. In the EAR, the patients with subsequent LAR had a greater fall in FEV1. Their baseline FEV1, and total dose of inhaled allergen were not significantly different from patients who did not develop a LAR, but their serum specific IgE level was higher. Crossed immunoelectrophoresis (CIE) of the same cat extract showed that it contained eight different proteins. An IgE-CRIE was obtained from all 21 patients, using radiolabelled anti-IgE and autoradiography. Radiolabelled standards allowed a semiquantitative scoring of the radiostaining. The CRIE pattern of the eight patients with LAR showed a higher score of radiostaining and a greater number of proteins bound to IgE. The two major allergen cat albumin and Fel dI bound equally to IgE of patients with and without LAR whereas another protein (antigen No. 7) bound to IgE of 100% of patients with LAR but of only 38% of patients without LAR. These data suggest that the pattern of the IgE response to specific proteins of a cat extract may be related to the occurrence of LAR after BPT with this allergen

Omalizumab in children with severe allergic disease: a case series

Abstract Background Currently, severe allergic asthma and food allergy in children represent an important public health problem with medical, psychosocial and economic impacts. Omalizumab is a humanized monoclonal anti-IgE antibody, approved for refractory allergic asthma and chronic urticaria. It has been widely used in clinical practice as add-on therapy in patients with severe uncontrolled allergic asthma. In recent years there has seen the emergence of an allergic epidemic with increasing food allergy, which represents the main cause of anaphylaxis in children. The standard of care for food allergy is strictly dietary allergen avoidance and emergency treatment, but recent clinical trials have suggested that omalizumab may have a role to play as an adjuvant to oral immunotherapy (OIT). We present a case series of patients treated at our institution with omalizumab for severe allergic asthma and food allergy. Methods Patients received omalizumab according to a standard reference nomogram after failing standard therapies. In children with comorbid severe food allergy, omalizumab was administered in conjunction with an oral immunotherapy protocol. Results Omalizumab was effective in controlling symptoms of allergic asthma, allergic rhinitis and rhinosinusitis, but not eosinophilic esophagitis, while aiding successful oral desensitization of comorbid severe food allergies. Conclusions Omalizumab appears to be an excellent therapeutic option in children with inadequately controlled severe allergic asthma, allergic rhinitis and rhinosinusitis, with or without food allergy