The inhibitory receptor superfamily: potential relevance to atopy

The role of inhibitory receptor superfamily (IRS) members in the pathophysiology of atopy is still largely unexplored but the past year or so has brought at least three important advances in the understanding of IRS member function: first, several targets of an inositol-phosphatase-dependent inhibitory signaling pathway utilized by some IRS members were identified; second, there is accumulating evidence from murine models supporting the importance of inhibitory Fc gamma receptors in modulating immune-complex-mediated inflammation; third, the inhibitory signaling capability of several previously identified candidate IRS members--including several expressed on cell types implicated in atopy and allergic reactions--has been demonstrated.     

The epidemiology of occupational contact dermatitis

Occupational contact dermatitis (OCD) ranks first of all occupational diseases in many countries. The incidence rate is believed to be around 0.5–1.9 cases per 1000 full-time workers per year. Epidemiological studies play an important role in observing disease trends, analysing risk factors, and monitoring the effect of preventive measures. In this review article the lack of truly epidemiologic data on OCD and the difficulties of those studies are illustrated. The following issues are highlighted: case ascertainment and bias, the distribution of allergic and irritant contact dermatitis in the working population, the interrelationship between exogenous (allergens, irritants) and endogenous factors, the prognosis, the social and economic impact, and the need for intervention studies. Received: 26 January 1999 / Accepted: 24 April 1999     

Natural rubber latex allergy: prevalence and risk factors in patients with spina bifida compared with atopic children and controls

Type 1 allergy against natural rubber latex is an increasing problem in health care workers and children with spina bifida or urogenital malformations. The aim of our study was to evaluate the prevalence of latex IgE antibodies and cross-reacting fruit antibodies in patients with spina bifida compared with atopic and non-atopic controls. Risk factors for sensitization should be determined. Sera of 148 patients with spina bifida and 98 controls (44 with atopy) were screened for IgE antibodies against latex, banana and kiwi by fluorescence enzyme immunoassay (CAP system). Atopies, allergic symptoms after latex contacts and the number of operations were compiled by a questionnaire. Patients with spina bifida developed latex IgE antibodies (≥0.7 kU/l) more frequently (40.5%) than atopic children (11.4%) or healthy controls (1.9%). All 18 symptomatic patients belonged to the spina bifida group and had high values of latex antibodies. The risk for developing latex antibodies increases with the number of operations. There was no difference in the history of atopic diseases and in a screening test of IgE antibodies against inhalative allergens between latex sensitized and not sensitized children with spina bifida. Antibodies against banana were more frequent in the latex sensitized children with spina bifida. (18.3% vs 3.4%, P = 0.002). Conclusion The high prevalence of latex antibodies in children with spina bifida justifies a primary prophylaxis by avoiding latex contacts, especially during anaesthesia and surgery, a correlation between the number of operations and the development of latex antibodies exists. Received: 30 March 1996 and in revised form: 19 March 1997 / Accepted: 20 March 1997     

Risk factors for asthma in schoolchildren in Southern Brazil

BackgroundDue to the high prevalence of recurrent wheezing in the pediatric population, it is important to be able to identify environmental risk factors that may affect the etiology of asthma in several regions.Objective: to identify possible risk factors associated with asthma in children (9–12 years old) in Passo Fundo, Rio Grande do Sul, Brazil.Material and MethodsA total of 1003 school-age children were selected for the cross-sectional study by applying a standardized written questionnaire from the International Study of Asthma and Allergy, and a supplementary questionnaire (ISAAC phase II) was added to address personal, family and environmental factors. Of these, 125 children were excluded because they did not accept to do the skin prick test, resulting in a sample of 878.ResultsIndependent risk factors associated with asthma were bronchiolitis before two years old [OR] = 3.11; 2.23–4.33, current rhinitis [0R] = 2.07; 1.43–3.0; sharing bedroom during the first year of life [OR] = 2.03; 1.36–3.04; atopy [OR] = 1,82; 1.26–2.50; use of paracetamol more than 12 times a year [OR] = 1.68; 1.20–2.31; use of antibiotics in the first six months of life [OR] = 1,57 1;13–2.17; maternal asthma [OR] = 1.75; 1.05–2.78, having an indoor cat during the first year of life [OR] = 1.73, 1.07–2.78; premature birth [OR] = 1.60,1.02–2.50.Conclusionour results show that genetic backgrounds, environmental factors, premature birth, use of antibiotics before six months of life, using paracetamol once per month and the presence of co-morbidities such as rhinitis are the risk factors associated with asthma in Brazilian children.     

Genetics of inflammation and atopy

Multiple chromosomal regions and polymorphisms of several candidate genes have been linked to or associated with atopic diseases (hayfever, asthma, allergic eczema and rhinitis). In this mini-review, we present data demonstrating that the genetic regulation of the inflammatory response makes a major contribution to the risk of atopy. These data also suggest that the quantity (or quality) of the inflammation affects the priming phase of atopy, i.e., that induced by allergens or infectious agents in early childhood.     

Bronchial Hyperresponsiveness in Farmers: Relation to Respiratory Symptoms, Lung Function, and Atopy

There is only limited information on the factors associated with nonspecific bronchial hyperresponsiveness (BHR) in farmers. Our purpose was to examine the relationship between BHR and respiratory symptoms, atopy, and abnormalities of lung function in a sample of French farmers. Farmers scheduled for a preventive medicine check-up in northeastern France were examined. Occupational exposure, respiratory symptoms, and work-related symptoms were assessed by questionnaire, sensitization to 34 common and agricultural allergens by skin prick tests, and BHR by the single-dose (1,200 μg) acetylcholine (ACh) challenge test. Data were obtained from 741 farmers (95% of those invited). Seventy-seven subjects (10.3%) had BHR defined as a fall in forced expiratory volume in 1 s (FEV₁) ≥ 10% after the inhalation of ACh or, for those with a poor lung function, an increase in FEV₁ > 10% and > 200 ml after the inhalation of 200 μg of salbutamol. The proportion of asthmalike symptoms, especially wheeze during work, positive skin tests to acarian (storage mites) and cereal dust allergens, and low levels of lung function was significantly greater among reactors than among nonreactors. Stepwise logistic regression analysis showed a significant and independent association between BHR and wheezing during work (OR = 4.99; 95% CI = 2.29–10.89; p= 0.0001) and baseline FEV₁ (OR = 1.49; 95% CI = 1.05–2.20; p= 0.026). In conclusion, hyperreactive farmers had significantly more asthmalike symptoms, positive skin tests, and abnormal lung function than normoreactive farmers. Work-related wheeze and low baseline FEV₁ were significantly and independently associated with BHR. Accepted for publication: 26 January 1999     

Spatial analysis of exposure to traffic-related air pollution at birth and childhood atopic asthma in Toronto,Ontario

Findings from the Toronto Child Health Evaluation Questionnaire (TCHEQ) study indicate that early childhood exposure to traffic-related air pollution (TRAP) is related to the onset of atopic childhood asthma. To test this hypothesis further, we investigated whether spatial patterns in the birth neighbourhood of TCHEQ subjects with atopic asthma (136 of 909 schoolchildren in grades 1–2) could be explained by TRAP and other risk factors. If a causal relationship exists between early childhood residential exposure to TRAP and the development of atopic asthma, we hypothesise that (1) clusters of current asthma should exist around the place of residence at birth, and (2) accounting for residential concentrations of TRAP at birth should explain some of the autocorrelation. Several high asthma clusters were observed. Adjusting for TRAP completely explained one cluster; elsewhere, clusters were only partially explained by TRAP. Findings suggest that exposure during early childhood to TRAP in Toronto is an important contributor to the development of the atopic asthma phenotype and reveal the likely importance of other risk factors not measured in the fixed effects of the model.     

Interleukin-13 Receptor A1 Gene Polymorphism and IL-13 Serum Level in Atopic and Non-atopic Egyptian Children

Objectives: To assess serum interleukin (IL) 13 levels in atopic diseases and to determine the role of IL-13R A₁ gene polymorphism (+1398 A/G) in pathogenesis of these diseases. Methods: Serum total immunoglobulin (Ig) E and IL-13 levels were measured by ELISA and the IL-13R A₁ gene (+1398 A/G) was screened by PCR-restriction fragment length polymorphism (RFLP) in 240 asthmatic children (120 atopic and 120 nonatopic) and 120 allergic rhinitis patients compared with 120 age-matched controls. Results: No significant association was observed between genotype frequencies of the IL-13R A₁ +1398 A/G polymorphism in patients groups compared to in controls. There was a significant increase in serum levels of total IgE & IL-13 towards heterozygous AG and homozygous GG than homozygous AA in atopic asthma, non-atopic asthma and allergic rhinitis groups (P < 0.001 for each). A highly significant increase of serum IL-13 in atopic asthma as compared with controls (P < 0.001) and with nonatopic asthmatics (P < 0.001) was shown. Conclusion: The IL-13R A₁ +1398 A/G polymorphism does not contribute to asthma or allergic rhinitis susceptibility, yet serum IL-13 can be used as a marker in atopic diseases and to differentiate between atopic and non-atopic asthma.