Different IgE recognition of mite allergen components in asthmatic and nonasthmatic children

Abstract

BackgroundHouse dust mites (HDMs) represent one of the most important inducers of respiratory allergies worldwide.ObjectiveWe sought to investigate the IgE and IgG reactivity profiles to a comprehensive panel of HDM allergens in children with allergic asthma and to compare them with those of nonasthmatic atopic children.MethodsSera from clinically well-characterized asthmatic children with HDM allergy (n = 105), nonasthmatic children (n = 53), and nonatopic nonasthmatic children (n = 53) were analyzed for IgE and IgG reactivity to a panel of 7 HDM allergens (nDer p 1, rDer p 2, rDer p 5, rDer p 7, rDer p 10, rDer p 21, and rDer p 23) by means of allergen microarray technology.ResultsAsthmatic children with HDM allergy more frequently showed an IgE response to each of the HDM allergens and recognized more allergens than nonasthmatic children with HDM allergy. Furthermore, IgE levels to certain HDM allergens (nDer p 1, P = .002; rDer p 2, P = .007; rDer p 5, P = .031; and rDer p 23, P < .001) were significantly higher in asthmatic children than in children without asthma. By contrast, fewer asthmatic children showed IgG reactivity to HDM allergens than nonasthmatic children, but allergen-specific IgG levels were comparable.ConclusionThe IgE and IgG reactivity profiles to HDM allergens, as well as IgE levels to certain allergen components, differed considerably between children with and without asthmatic symptoms caused by HDM allergy. In fact, asthmatic children were characterized by an expanded IgE repertoire regarding the numbers of recognized allergen components and by increased specific IgE levels.

Association Between Asthma and Sensitization to Allergens of Dermatophagoides pteronyssinus

“…It is also consistent with the findings of a recent case-control study, which showed that the more HDM allergens children recognize, the higher their risk of asthma [2]. Therefore, even though our results are more consistent with those reported by Custovic et al [1], the design of our study is more consistent with that of Resch et al [2], where the risk of asthma was found to be >2-fold higher in patients with sIgE to rDer p 2. Nevertheless, the highest risk was found among patients with sIgE to rDer p 5, which was not measured in the present study because it is not available for ImmunoCAP [2].…”

“…Therefore, even though our results are more consistent with those reported by Custovic et al [1], the design of our study is more consistent with that of Resch et al [2], where the risk of asthma was found to be >2-fold higher in patients with sIgE to rDer p 2. Nevertheless, the highest risk was found among patients with sIgE to rDer p 5, which was not measured in the present study because it is not available for ImmunoCAP [2]. In addition, Resch et al [2] did not evaluate the possible association with dual sensitization.…”

“…This observation is consistent with recent data from a longitudinal study indicating a higher risk of asthma in children with this pattern of sensitization [1]. It is also consistent with the findings of a recent case-control study, which showed that the more HDM allergens children recognize, the higher their risk of asthma [2]. Therefore, even though our results are more consistent with those reported by Custovic et al [1], the design of our study is more consistent with that of Resch et al [2], where the risk of asthma was found to be >2-fold higher in patients with sIgE to rDer p 2.…”

“…Nevertheless, the highest risk was found among patients with sIgE to rDer p 5, which was not measured in the present study because it is not available for ImmunoCAP [2]. In addition, Resch et al [2] did not evaluate the possible association with dual sensitization. Of note, we confirmed that dual sensitization was associated with asthma in older age groups (adolescents and adults), although we have no data on the possible association between this sensitization profile and the severity of asthma.…”

“…Today, however, the availability of natural and recombinant allergens of Dermatophagoides species makes it possible to investigate whether a specific molecular reactivity profile is associated with clinical manifestations in HDM-allergic individuals. Two recently published studies [1,2] suggest that ISAC microarray-based determination of IgE against various Dermatophagoides components may be of value in defining the risk of developing asthma in children. In the first study, the authors followed 235 children with so-called complete mite sensitization-recognition of specific IgE (sIgE) against both Der p 1 and Der p 2 allergens-from age 5 to 11 years and found a higher risk of asthma, more frequent airway inflammation, and more severe exacerbations [1].…”