Written questionnaires (WQ) have been widely used in epidemiologic studies. In order to yield comparable results, they must be validated after translation to another language. The International Study of Asthma and Allergies in Childhood (ISAAC) WQ has been previously validated by a comprehensive study, but its validation in Brazil has not been performed. Our objectives were to validate the rhinitis component of the ISAAC's self-applicable WQ following its translation to Portuguese, and to determine the prevalence of rhinitis and related symptoms among Brazilian children living in the city of São Paulo. A group of 10 pediatricians and 10 pediatric allergists graded the questions from 0 to 2 and established a maximum score for each question. The WQ was answered by parents or guardians of children 6-7 years of age with rhinitis (R) (n = 27) and of control children of the same age without rhinitis (C) (n = 27). The WQ was also completed by adolescents 13-14 years of age with rhinitis (R) (n = 32) and without rhinitis (C) (n = 32). Half of these individuals answered the same WQ after 2-4 weeks, to ensure reproducibility. Cut-off scores of 4 and 3 were identified for the 6-7- and 13-14-year-old groups, respectively, as scores predictive of rhinitis. The prevalence of rhinitis was 28.8% in the group of 3005 children 6-7 years of age and 31.7% in the group of 3008 children 13-14 years of age, respectively. Using the global cut-off score, these prevalences were even higher, in the order of 34.7% and 40.7%, respectively. In conclusion, the rhinitis component of the ISAAC WQ was proven to be reproducible, adequate and able to discriminate children and adolescents with and without rhinitis, and revealed that the prevalence of rhinitis among Brazilian children living in the city of São Paulo was as high as the prevalence of rhinitis in other areas of the world.

Background It is not clear if cross-reactivity or co-sensitization to glutathione S-transferases (GST) occurs in tropical and subtropical environments. In the United States, Bla g 5 is the most important GST allergen, and lack of co-exposure to GST from certain species allows a better assessment of cross-reactivity. Objectives To examine the molecular structure of GST allergens from cockroach (Bla g 5), dust mites (Der p 8, Blo t 8) and helminth (Asc s 13) for potential cross-reactive sites, and to assess the IgE cross-reactivity of sensitized patients from a temperate climate for these allergens for molecular diagnostic purposes. Methods Four crystal structures were determined. Sera from cockroach and mite allergic patients were tested for IgE reactivity to these GST. A panel of six murine anti-Bla g 5 mAb was assessed for cross-reactivity with the other three GST using antibody binding assays. Results Comparisons of the allergen structures, formed by two-domain monomers that dimerize, revealed few contiguous regions of similar exposed residues, rendering cross-reactivity unlikely. Accordingly, anti-Bla g 5 or anti-Der p 8 IgE from North American patients did not recognize Der p 8 or Bla g 5, respectively, and neither showed binding to Blo t 8 or Asc s 13. A weaker binding of anti-Bla g 5 IgE to Der p 8 versus Bla g 5 (~100-fold) was observed by inhibition assays, similar to a weak recognition of Der p 8 by anti-Bla g 5 mAb. Patients from tropical Colombia had IgE to all four GST. Conclusions The lack of significant IgE cross-reactivity among the four GST is in agreement with the low shared amino acid identity at the molecular surface. Each GST is needed for accurate molecular diagnosis in different geographic areas.

A large number of allergens have been discovered but we know little about their potential to induce inflammation (allergenic activity) and symptoms. Nowadays, the clinical importance of allergens is determined by the frequency and intensity of their IgE antibody binding (allergenicity). This is a rather limited parameter considering the development of experimental allergology in the last 20 years and the criteria that support personalized medicine. Now it is known that some allergens, in addition to their IgE antibody binding properties, can induce inflammation through non IgE mediated pathways, which can increase their allergenic activity. There are several ways to evaluate the allergenic activity, among them the provocation tests, the demonstration of non-IgE mediated pathways of inflammation, case control studies of IgE-binding frequencies, and animal models of respiratory allergy. In this review we have explored the current status of basic and clinical research on allergenic activity of indoor allergens and confirm that, for most of them, this important property has not been investigated. However, during recent years important advances have been made in the field, and we conclude that for at least the following, allergenic activity has been demonstrated:

The objective of this study was to evaluate risk factors for persistent wheezing in a group of 2-4-year-old children after an index-wheezing episode in infancy. Eighty infants who had been seen at the Emergency Department for an episode of acute wheezing were followed for 2 yr in this prospective study. Caregivers completed a questionnaire, and children underwent clinical evaluation and skin prick testing 2 yr following the index-wheezing episode. Detection of respiratory viruses and analysis of exposure to major indoor allergens were carried out at enrollment. Immunoglobin E antibodies were measured at the beginning of the study and at the end of follow-up, using the CAP system. Logistic regression analysis was performed to identify factors associated with persistent wheezing. Seventy-three children (44 boys) completed the study. After 2 yr, 38 (52%) reported three or more wheezing episodes in the past 12 months (persistent wheezers). Independent risk factors for persistence of wheezing were allergic sensitization and exposure to cockroach allergen in the kitchen. Breast-feeding for at least 1 month was a protective factor. A strong association between allergic sensitization and persistence of wheezing was found in a group of very young children living in a subtropical area.

Epidemiological and experimental evidence supports the notion that microbial infections that are known to induce Th1-type immune responses can suppress Th2 immune responses, which are characteristics of allergic disorders. However, live microbial immunization might not be feasible for human immunotherapy. Here, we evaluated whether induction of Th1 immunity by the immunostimulatory sequences of CpG-oligodeoxynucleotides (CpG-ODN), with or without culture filtrate proteins (CFP), from Mycobacterium tuberculosis would suppress ongoing allergic lung disease. Presensitized and ovalbumin (OVA)-challenged mice were treated subcutaneously with CpG, or CpG in combination with CFP (CpG/CFP). After 15 days of treatment, airway inflammation and specific T-and B-cell responses were determined. Cell transfer experiments were also performed. CpG treatment attenuated airway allergic disease; however, the combination CpG/CFP treatment was significantly more effective in decreasing airway hyperresponsiveness, eosinophilia and Th2 response. When an additional intranasal dose of CFP was given, allergy was even more attenuated. The CpG/CFP therapy also reduced allergen-specific IgG1 and IgE antibodies and increased IgG2a. Transfer of spleen cells from mice immunized with CpG/CFP also reduced allergic lung inflammation. CpG/CFP treatment induced CFP-specific production of IFN-c and IL-10 by spleen cells and increased production of IFN-c in response to OVA. The essential role of IFN-c for the therapeutic effect of CpG/CFP was evidenced in IFN-c knockout mice. These results show that CpG/CFP treatment reverses established Th2 allergic responses by an IFN-c-dependent mechanism that seems to act both locally in the lung and systemically to decrease allergen-specific Th2 responses.