BACKGROUND: Studies on the association of birth by caesarean section (C/S) and allergies have produced conflicting findings. Furthermore, evidence on whether this association may differ in those at risk of atopy is limited. This study aims to investigate the association of mode of delivery with asthma and atopic sensitization and the extent to which any effect is modified by family history of allergies. METHODS: Asthma outcomes were assessed cross-sectionally in 2216 children at age 8 on the basis of parents' responses to the ISAAC questionnaire whilst skin prick tests to eleven aeroallergens were also performed in a subgroup of 746 children. Adjusted odds ratios of asthma and atopy by mode of delivery were estimated in multivariable logistic models while evidence of effect modification was examined by introducing interaction terms in the models. RESULTS: After adjusting for potential confounders, children born by C/S appeared significantly more likely than those born vaginally to report ever wheezing (OR 1.36, 95% CI 1.07-1.71), asthma diagnosis (OR 1.41, 95% CI 1.09-1.83) and be atopic (OR 1.67, 95% CI 1.08-2.60). There was modest evidence that family history of allergies may modify the effect of C/S delivery on atopy (p for effect modification=0.06) but this was not the case for the asthma outcomes. Specifically, while more than a two-fold increase in the odds of being a topic was observed in children with a family history of allergies if born by C/S (OR 2.62, 95% CI 1.38-5.00), no association was observed in children without a family history of allergies (OR 1.16, 95% CI 0.64-2.11). CONCLUSIONS: Birth by C/S is associated with asthma and atopic sensitization in childhood. The association of C/S and atopy appears more pronounced in children with family history of allergies.
For many years, pathogenetic concepts and the results of clinical trials supported the view that anti-IgE treatment is specifically effective in allergic asthma. However, there is now growing clinical and mechanistic evidence suggesting that treatment with the anti-IgE antibody omalizumab can be effective in patients with intrinsic asthma. Therefore, large and well-controlled clinical trials with anti-IgE are urgently warranted in patients with intrinsic asthma. In addition, there is a need to find new biomarkers which can identify patients with asthma who respond to anti-IgE treatment.
Crosslinking of immunoglobulin E antibodies (IgE) bound at the surface of mast cells and subsequent mediator release is considered the most important trigger for allergic reactions. Therefore, the genetic control of IgE levels is studied in the context of allergic diseases, such as asthma, atopic rhinitis, or atopic dermatitis (AD). We performed genome-wide association studies in 161 Labrador Retrievers with regard to total and allergen-specific immunoglobulin E (IgE) levels. We identified a genome-wide significant association on CFA 5 with the antigen-specific IgE responsiveness to Acarus siro. We detected a second genome-wide significant association with respect to the antigen-specific IgE responsiveness to Tyrophagus putrescentiae at a different locus on chromosome 5. A. siro and T. putrescentiae both belong to the family Acaridae and represent so-called storage or forage mites. These forage mites are discussed as major allergen sources in canine AD. No obvious candidate gene for the regulation of IgE levels is located under the two association signals. Therefore our studies offer a chance of identifying a novel mechanism controlling the host’s IgE response.
Evaluation of recombinant MGL_1304 produced by Pichia pastoris for clinical application to sweat allergy
- Allergology international : official journal of the Japanese Society of Allergology
- Published over 3 years ago
We previously identified MGL_1304 secreted by Malassezia globosa as a sweat antigen for patients with atopic dermatitis (AD) and cholinergic urticaria (ChU). However, purifying native MGL_1304 from human sweat or culture supernatant of M. globosa (sup-MGL_1304) is costly and time-consuming. Moreover, recombinant MGL_1304 expressed by using Escherichia coli (TF-rMGL_1304) needs a large chaperon protein and lacks the original glycosylation of yeasts. Thus, we generated a recombinant MGL_1304 by Pichia pastoris (P-rMGL_1304) and investigated its characteristic features.
- Allergology international : official journal of the Japanese Society of Allergology
- Published about 2 years ago
Given the importance of appropriate diagnosis and appropriate assessment of cutaneous symptoms in treatment of atopic dermatitis, the basics of treatment in this guideline are composed of (1) investigation and countermeasures of causes and exacerbating factors, (2) correction of skin dysfunctions (skin care), and (3) pharmacotherapy, as three mainstays. These are based on the disease concept that atopic dermatitis is an inflammatory cutaneous disease with eczema by atopic diathesis, multi-factorial in onset and aggravation, and accompanied by skin dysfunctions. These three points are equally important and should be appropriately combined in accordance with the symptoms of each patient. In treatment, it is important to transmit the etiological, pathological, physiological, or therapeutic information to the patient to build a favorable partnership with the patient or his/her family so that they may fully understand the treatment. This guideline discusses chiefly the basic therapy in relation to the treatment of this disease. The goal of treatment is to enable patients to lead an uninterrupted social life and to control their cutaneous symptoms so that their quality of life (QOL) may meet a satisfactory level. The basics of treatment discussed in this guideline are based on the “Guidelines for the Treatment of Atopic Dermatitis 2008” prepared by the Health and Labour Sciences Research and the “Guidelines for the Management of Atopic Dermatitis 2015 (ADGL2015)” prepared by the Atopic Dermatitis Guidelines Advisory Committee, Japanese Society of Allergology in principle. The guidelines for the treatment of atopic dermatitis are summarized in the “Japanese Guideline for the Diagnosis and Treatment of Allergic Disease 2016” together with those for other allergic diseases.
Few studies addressed trans-regional differences in allergen sensitization between areas within a similar latitudinal range but with distinct geomorphological features. We investigated specific IgE (sIgE) positivity to common allergens in populations from two southern China provinces. Using a uniformed protocol, serum samples were collected from 2778 subjects with suspected atopy in coastal Guangdong and inland Yunnan. The overall prevalence of sIgE positivity were 57.8% (95% CI: 56.0%, 59.6%) from Guangdong vs 60.9% (95% CI: 59.1%, 62.7%) from Yunnan. House dust mite (d1) was the most common allergen in both regions. Among d1-sensitized subjects, only 35.7% (208/583) in Guangdong and 22.9% (147/642) in Yunnan tested positive for d1 alone. Among those poly-sensitized d1-positive subjects, cockroach was the most common co-sensitizing aeroallergen. 41.9% of the d1-sensitized Guangdong subjects showed high-class sIgE reactivity (≥class 4), in contrast to a very low percentage of such reactivity in Yunnan. However, 36.3% of d1-sensitized subjects in Yunnan were concomitantly positive for tree pollen mix. Surprisingly, Yunnan subjects showed high prevalence of sIgE positivity for crabs and shrimps, either by overall or by age-group analysis, compared with their Guangdong counterparts (both P < 0.05). These findings may add to data about local allergies in China and worldwide.
Additional topical treatments for atopic dermatitis (AD) are needed that provide relief while minimizing risks.
The role of clothing in the management of eczema (also called atopic dermatitis or atopic eczema) is poorly understood. This trial evaluated the effectiveness and cost-effectiveness of silk garments (in addition to standard care) for the management of eczema in children with moderate to severe disease.
The hygiene hypothesis suggests that early-life exposure to microbial organisms reduces the risk of developing allergies. Thumb-sucking and nail-biting are common childhood habits that may increase microbial exposures. We tested the hypothesis that children who suck their thumbs or bite their nails have a lower risk of developing atopy, asthma, and hay fever in a population-based birth cohort followed to adulthood.
Allergic reactions can be considered as maladaptive IgE immune responses towards environmental antigens. Intriguingly, these mechanisms are observed to be very similar to those implicated in the acquisition of an important degree of immunity against metazoan parasites (helminths and arthropods) in mammalian hosts. Based on the hypothesis that IgE-mediated immune responses evolved in mammals to provide extra protection against metazoan parasites rather than to cause allergy, we predict that the environmental allergens will share key properties with the metazoan parasite antigens that are specifically targeted by IgE in infected human populations. We seek to test this prediction by examining if significant similarity exists between molecular features of allergens and helminth proteins that induce an IgE response in the human host. By employing various computational approaches, 2712 unique protein molecules that are known IgE antigens were searched against a dataset of proteins from helminths and parasitic arthropods, resulting in a comprehensive list of 2445 parasite proteins that show significant similarity through sequence and structure with allergenic proteins. Nearly half of these parasite proteins from 31 species fall within the 10 most abundant allergenic protein domain families (EF-hand, Tropomyosin, CAP, Profilin, Lipocalin, Trypsin-like serine protease, Cupin, BetV1, Expansin and Prolamin). We identified epitopic-like regions in 206 parasite proteins and present the first example of a plant protein (BetV1) that is the commonest allergen in pollen in a worm, and confirming it as the target of IgE in schistosomiasis infected humans. The identification of significant similarity, inclusive of the epitopic regions, between allergens and helminth proteins against which IgE is an observed marker of protective immunity explains the ‘off-target’ effects of the IgE-mediated immune system in allergy. All these findings can impact the discovery and design of molecules used in immunotherapy of allergic conditions.