Correlation between inhalant allergen-specific IgE and pulmonary function in children with asthma

Sensitization to aeroallergens is associated with diminished lung function in adults. Little has been studied on the relationship between the inhalant allergen-specific IgE and pulmonary function in asthmatic children. This study was focused on four major inhalant allergens found in Korea, including Dermatophagoides pteronyssinus (Der p.), Dermatophagoides farinae (Der f.), and Alternaria- and German cockroach-specific IgEs, with evaluation of pulmonary function in relation to the amount of allergens. The parents or legal guardians of participants enrolled in this study gave informed consent. Fifty-five asthmatic patients and 48 nonasthmatic children were included. The amounts of specific IgE for the four specified inhalant allergens were determined by employing the CAP system FEIA. Forced expiratory volume in 1 sec (FEV(1))/forced vital capacity (FVC), FEV(1), and forced expiratory flow between 25% and 75% of FVC (FEF(25-75)) of subjects were evaluated through pulmonary function tests. In the asthmatic group, FEV(1), FEV(1)/FVC, and FEF(25-75) were significantly reduced (P < 0.05): reduction in FEV(1) (r = -0.44) and FEF(25-75) (r = -0.33) in association with the Der f.-specific allergen, and reduction in FEV(1) (r = -0.37) and FEF(25-75) (r = -0.34) in association with the Der p.-specific allergen, were observed. However, there was no significant correlation with German cockroach and Alternaria allergen. In the control group, no significant correlation was detectable between the allergen-specific IgE titers and the results of pulmonary function tests. In asthmatic patients, Der p.- and Der f.-specific IgEs, and not German cockroach and Alternaria, seem to play a considerable role in reduced pulmonary function among asthmatic children.     

安脱达尘螨疫苗治疗儿童过敏性哮喘的疗效及安全性评价

目的:评价安脱达尘螨变应原疫苗治疗过敏性哮喘的疗效及安全性。方法:采用自身对照方法,对125例尘螨过敏性哮喘患儿皮下注射特异性免疫疫苗(安脱达),记录治疗前后哮喘症状、合并用药评分,同时计算与免疫相关不良反应发生率,评价其安全性。结果:脱敏治疗1年后125例患儿哮喘症状明显改善,合并用药计分明显减少。80.0%(100/125)的哮喘患儿伴发过敏性鼻炎,脱敏治疗1年后鼻炎症状明显改善。23.2%的患儿因哮喘症状明显好转,在治疗第26周末自行停用合并药物,第52周末随访病情,哮喘复发率为10.3%(3/29)。125例患儿总计接受免疫治疗注射2676次,43例患儿出现100例次局部不良反应,局部不良反应的发生率为3.7%(100/2676),14例患儿出现23例次全身不良反应,全身不良反应发生率0.9%(23/2676),未出现致死性全身不良反应。结论:标准化变应原进行脱敏治疗在规范化操作下是一种安全有效的治疗方法。     

Anti-inflammatory modulation of chronic airway inflammation in the murine house dust mite model

Asthma affects 300 million people worldwide and continues to be a major cause of morbidity and mortality. Disease relevant animal models of asthma are required for benchmarking of novel therapeutic mechanisms in comparison to established clinical approaches. We demonstrate that chronic exposure of mice to house dust mite (HDM) extract results in allergic airway inflammation, that can be significantly attenuated by therapeutic intervention with phosphodiesterase 4 inhibition and corticosteroid treatment. Female BALB/c mice were administered intranasally with HDM (Dermatophagoides pteronyssinus) extract daily for five weeks, and therapeutic intervention with anti-inflammatory treatment (dexamethasone 1 mg/kg subcutaneous once daily, prednisolone 10mg/kg orally twice daily, fluticasone 3, 10 and 30 microg intranasally twice daily, roflumilast 10 mg/kg orally twice daily and intranasally 10 and 30 microg twice daily) was initiated after three weeks of exposure. Chronic HDM extract exposure resulted in significant airway inflammation, demonstrated by bronchoalveolar lavage cell infiltration and lung tissue inflammatory gene expression by TaqMan low density array. Chronic steroid treatment significantly inhibited these parameters. In addition, roflumilast caused a significant reduction in airway inflammatory cell infiltration. We have demonstrated that chronic HDM-induced allergic inflammation can be significantly ameliorated by steroid treatment, and that phosphodiesterase 4 inhibition modulates inflammatory cell infiltration. Therefore, the murine HDM model may be a useful tool for evaluating new targets for the treatment of asthma.     

Association of Single Nucleotide Polymorphisms in the MD-2 Gene Promoter Region With Der p 2 Allergy

Purpose

Sensitization to house dust mite (Dermatophagoides pteronyssinus) is a considerable risk factor for the progression of allergic disease. The group 2 allergen from Dermatophagoides pteronyssinus, Der p 2, is considered a major one in patients with specific immunoglobulin E (IgE) to Der p 2. Der p 2 has structural homology with myeloid differentiation 2 (MD-2), which is involved in the lipopolysaccharide-binding component of the Toll-like receptor 4 signaling pathway and the development of inflammation. The aim of this study was to examine the genetic association of single nucleotide polymorphisms (SNPs) in the promoter region of MD-2 with Der p 2-sensitive allergy.

Methods

We investigated associations between cohort''s characteristics, including 280 allergic and 80 healthy subjects by examining total IgE, eosinophils, D. pteronyssinus-specific IgE, Der p 2-specific IgE, the number of IgE-producing B cells induced by Der p 2, and the odds ratio of allergic symptoms.

Results

Based on the 1,000 genome project data, the minor allele frequencies of the rs1809441 and rs1809442 are 0.467 and 0.474, respectively. However, the correlation of linkage disequilibrium (LD) between these 2 SNPs is D''=1, the genotype frequencies of the 2 MD-2 (LY96) SNPs (rs1809441 and rs1809442) that are located nearby were significantly different between allergic and health subjects: the TT genotype of rs1809441 and the GG genotype of rs1809442 were more frequent in allergic subjects than in healthy subjects (16.1% vs 2.5% in both genotypes). The allergic patients with these genotypes exhibited significantly higher levels of D. pteronyssinus-specific IgE and Der p 2-specific Ig E, and a larger number of Der p 2-activated B cells. In addition, these 2 SNPs in the MD-2 promoter region were significantly associated with the prevalence of nasal, skin, and asthmatic allergic symptoms.

Conclusions

Our results indicated that 2 SNPs in the MD-2 promoter region were significantly associated with Der p 2-specific Ig E, and thereby suggest that these SNPs may play a major role in susceptibility to Der p 2-triggered immune responses in a Taiwanese population.     

厩真厉螨的研究现状

在检索、归纳和总结国内外相关文献基础上,本文综述了厩真厉螨的发现及命名、分布、生活史、致病性、流行病学意义等方面的研究现状,旨在为厩真厉螨及其传播疾病的监测和防控提供参考资料。     

螨制剂舌下免疫治疗对单一和多重致敏变应性鼻炎的疗效评估

目的观察单一和多重变应性鼻炎患者舌下脱敏的疗效异同并分析原因。方法回顾性分析舌下脱敏治疗1年以上单一和多重变应性鼻炎患者终止治疗1年后的疗效,并对粉尘螨变应原组分与其他点刺变应原作同源进化树分析。结果纳入患者50例,舌下免疫治疗显效22例,有效15例,无效13例,总有效率为74%。50例患者中30例(60%)为多重变态反应患者,阳性率最高的前3种变应原依次为蟑螂(83%)、冬季花粉(70%)和蚕丝(63%)。用有序多分类资料比较的秩和检验分析舌下脱敏治疗1年以上单一尘螨过敏患者与多重变态反应患者的疗效,两组总体分布相同。结论使用舌下含服粉尘螨滴剂治疗变应性鼻炎,多重与单一尘螨变态反应患者治疗效果相当。粉尘螨滴剂亦可用于多重变态反应患者常规治疗。     

尘螨过敏哮喘患儿家长家庭环境控制调查分析

目的评估尘螨过敏性哮喘患儿家长对家庭环境控制的知识、态度信念及行为,为居家环境干预及健康教育管理提供依据。方法用自行设计的一般资料调查表和螨过敏性哮喘家庭环境控制知信行评估表对153名尘螨过敏性哮喘患儿家长进行调查。结果过敏性哮喘家庭环境控制知信行总分79.76±4.66,其中知识维度得分11.27±1.76、态度和信念维度得分19.76±1.58、行为维度得分48.71±2.79。结论患儿家长螨过敏性哮喘家庭环境控制知识得分较低,对相关知识缺乏本质理解;对家庭环境控制的信念及行为较好。护理人员应加强患儿家长尘螨相关知识教育及居家环境干预行为的指导。     

New opportunities for allergen immunotherapy using synthetic peptide immuno-regulatory epitopes (SPIREs)

Introduction: Allergen immunotherapy (AIT) reduces allergic rhinoconjunctivitis (ARC) symptoms, but long-term efficacy requires treatment for 3–5 years. Synthetic peptide immuno-regulatory epitopes, a new class of AIT, are allergen peptides with a shorter, more convenient treatment regimen that could potentially have benefits on adherence and outcomes.

Areas covered: Phase 2 trials of therapies derived from cat, house dust mite, grass, and ragweed allergen peptides demonstrated significant reduction in ARC symptoms after short-course treatment; improvement was sustained for 18–24 months posttreatment. We conducted a PubMed literature search for clinical publications using the search terms AIT; allergen peptides; ARC; cat, grass, house dust mite, and ragweed allergy; SCIT; SLIT; and synthetic peptides.

Expert commentary: Long-term disease modification is a realistic goal of AIT. The inconvenience of conventional AIT regimens negatively impacts long-term persistence and, thus, efficacy. In comparison, SPIREs have a more convenient treatment regimen that could potentially have benefits on adherence and outcomes.     

Seasonal trends in house dust mite allergen in children's beds over a 7-year period

BACKGROUND: House dust mite (HDM) allergy is closely linked to the expression of asthma and other allergic diseases. Understanding factors influencing variation in allergen may help in controlling allergic disease. The objective of this study was to investigate the effects of seasonal changes in climate, type of bed used in very early childhood and anti-mite interventions on HDM allergen concentration. METHODS: Participants were enrolled in a randomized-controlled trial of HDM avoidance. Der p 1 was measured in dust samples from children's beds on 13 occasions, from birth to age 5 years, between 1997 and 2004. Bed types were categorized as bassinette, cot or bed. The effects of study month, type of bed and intervention group on HDM allergen concentration were estimated by multiple linear regression. The relation between climatic variables and HDM allergen concentration was investigated using a polynomial distributed lag model. RESULTS: House dust mite allergen concentrations were initially low in cots and bassinettes in 1997/1998, peaked in bassinettes and beds between 1999 and 2001 and then slowly declined during the period 2002/2004. Seasonal fluctuations occurred with minima in summer and two- to threefold higher maxima during late autumn. Allergen peaks were correlated with relative humidity peaks 2 months previously. Seasonal changes in allergen were not affected by the HDM avoidance intervention. CONCLUSIONS: House dust mite allergen concentrations in Sydney beds fluctuate approximately two- to threefold on an annual cycle, partly determined by relative humidity, with peaks in late autumn and minima in summer. Fluctuations of this magnitude might be sufficient to influence asthma symptoms.