Atopic diseases and upper respiratory infections

Asthma prevalence and severity in Arab American communities in the Detroit area, Michigan

Immigrant populations provide a unique intersection of cultural and environmental risk factors implicated in asthma etiology. This study focuses on asthma prevalence and severity in 600 Arab American households in metro Detroit, the largest immigrant reception zone for Arab Americans in North America. The survey method introduced a number of novel features: (a) a ranking scheme for the key environmental risk factors for asthma was used to derive an aggregated environmental risk index (ERI) for each household, and (b) an aggregate measure of asthma severity based on symptom frequency and intensity. Environmental risk factors and surrogates for socioeconomic status (SES) were found to be stronger predictors of asthma prevalence than asthma severity, while demographic variables such as English fluency and birth in the United States were better predictors of asthma severity than asthma prevalence. These results suggest that SES variables may be more reflective of environmental exposures in communities involved in this study, while English fluency and birth in the United States may be linked to health care access and utilization behavior that can influence the asthma management. We also found a significant relationship between asthma prevalence and degree of acculturation. Asthma prevalence was highest among moderately acculturated immigrants compared with new immigrants and those who were well acculturated, suggesting that among Arab Americans in the Detroit area, risk factors associated with new immigrant status are replaced by "western" risk factors as the population becomes more acculturated.

Infection with influenza a virus leads to flu antigen-induced cutaneous anaphylaxis in mice

It is well established, that viral infections may trigger urticaria or allergic asthma; however, as viral infections induce T helper 1 polarized responses, which lead to the inhibition of T helper 2 cell development, the opposite would be plausible. We wanted to investigate how viral infections may mediate allergic symptoms in a mouse model; therefore, we infected BALB/C mice with influenza A virus intranasally. Histologic analyses of lung sections and bronchoalveolar lavages were performed. In addition, cells from the mediastinal lymph nodes were restimulated in vitro to analyze which types of cytokines were induced by the flu infection. Furthermore, flu-specific antibody titers were determined and local anaphylaxis was measured after rechallenge with flu antigen. We found that airways inflammation consisted predominately of macrophages and lymphocytes, whereas only a few eosinophils were observed. interferon-gamma but no interleukin-4 and little interleukin-5 could be detected in the culture supernatants from in vitro restimulated T cells from the draining lymph nodes. The antibody response was characterized by high levels of virus-specific IgG2a, IgG2b, and IgG1 and, surprisingly, low levels of virus-specific IgE antibodies. Interestingly, flu-infected mice developed active and passive cutaneous anaphylaxis after rechallenge with flu-antigen. As the passive cutaneous anaphylaxis reaction persisted over 48 h and was significantly lower after passive transfer of the serum, which was IgE depleted, local anaphylaxis seemed to be mediated predominately by specific IgE antibodies. Taken together, our results demonstrate that mice infected with flu virus develop virus-specific mast cell degranulation in the skin. Our results may also have implications for the pathogenesis of urticaria or other atopic disorders in humans.

Sublingual allergen-specific immunotherapy in allergic rhinitis and related pathologies: Efficacy in a paediatric population

The aim of this study was to demonstrate the efficacy and safety of the sublingual-swallow allergen-specific immunotherapy (SLIT) in a paediatric population suffering from allergic rhinitis and related pathologies. From March 1994 through March 2000, at our ENT Department 4000 children (1800 male and 2200 female), aged 3 to14 years, were examined for recurrent nasal obstruction and nasal polyps. 2400 (60%) of them were allergic and underwent the following investigations: Impedance test, Pure tone audiometry, rhinomanometry, Prick test, RAST, nasal provocation test and paranasal sinus TC without contrast media. Of the allergic group we admitted 288 patients(12%) to a 3 yr SLIT, meeting the following criteria: children aged 5 years or more, mono-sensitised to one allergen and with family cooperation support. After three years of SLIT, we observed complete symptom remission and a marked improvement in instrumental examinations in 80% of these children. The improvement was poor in 8% of patients, while in 12% of the subjects no changes in symptoms and instrumental results were detected. These results are in agreement with previously published studies and confirm that SLIT can be a valid tool for treating allergic upper respiratory tract diseases in children.