Socio-environmental profile of child and adolescents sensitized by house dust mite in northeast of Brazil

IntroductionThe association regarding the atopic sensitization to mite aeroallergens and the socio-environmental features is still inconsistent.ObjectivesWe analyzed the role played by socioeconomic and environmental factors in the prevalence of sensitization to house dust mite (HDM) allergens, and associated with the risk of developing asthma symptoms.Patients and methodsThis is a case–control study conducted with 108 patients, aged 1–17. We inquired about family habits, socioeconomic and environmental features. We applied the International Study of Asthma and Allergies in Childhood questionnaire.ResultsWe observed patients sensitized to all HDM tested, Derp (42%), Derf (37%) and Blot (33%). Middle family income (OR: 2.74; CI95%: 1.127–6.684), exposure to dog (OR: 3.758, CI95%: 1.127–6.684) and artificial climatization (OR: 4.319, CI95%: 1.398–13.348) were associated with sensitization to Derp. We also observed protective factors, such as sharing of dormitories, washing cycle for bedspreads and the presence of basic sanitation. An increased risk of sensitization to Derf was associated with Blot sensitization (OR: 3.172, CI95%: 1.083–9.292) and presence of mold on the walls (OR: 3.095, CI95%: 1.063–9.008). A protective factor was dormitory sharing. For sensitization to Blot, we observed an increase in the risk associated with Derp sensitization (OR: 3.462, CI95%: 1.191–10.061) and exposure to dog (OR: 3.255, CI95%: 0.987–10.736). In addition, sensitization to Blot increases the risk of developing asthma symptoms (OR: 2.732, CI95%: 0.981–7.606).ConclusionOur data show distinct sociodemographic and environmental relations that lead to HDM sensitization and increased probability of development of allergic diseases.     

Microbiome in the primary prevention of allergic diseases and bronchial asthma

Tremendous progress in the ability to identify and test the function of microorganisms in recent years has led to a much better understanding of the role of environmental and host microbiome in the development of immune function, allergic sensitization and asthma. In this review, the most recent findings on the relationships between environmental microbiota, respiratory, intestinal microbiome, the consequences of early-life microbial exposure type and gut–lung microbial axis and the development of asthma and atopy are summarized. The current perspective on gut and airway microbiome manipulation for the primary prevention of allergic diseases and asthma is also discussed.     

The level of allergens in dust samples collected from selected schools in Shiraz,Iran and its asthma-risk implications

BackgroundBoth home and school are important places where children are exposed to various indoor allergens. This study aimed to identify the profile of indoor allergens in schools and its impact on asthma development.MethodsA total of 104 classrooms from 52 schools were selected for dust collection during the fall of 2017. The levels of indoor allergens including dust mite (Der f1, Der p1), cat (Fel d1), cockroach (Bla g1) and mouse (Mus m1) were measured by enzyme linked immunosorbent assay (ELISA). The diagnosis of asthma was made in all students of the selected classes by the allergist. The collected data were analyzed using SPSS version 21.0.ResultsOut of 2816 students in the selected classes, 180 students were involved with asthma. Students were mostly exposed to Bla g1 (83.1%), followed by Der f1 (51.5%), Mus m 1 (45.5%), Der p1 (8.9%) and Fel d1 (7.9%) in the dust collected from 101 classrooms. Although levels of all studied allergens in the settled dust of the classrooms were low, there was a relationship between Fel d1 in the classroom dust and development of asthma.ConclusionThis study showed considerable levels of cockroach allergens in schools. Exposure to cat allergen in our schools played an important role in asthma development; further school-based investigations require evaluating the role of classroom allergen on asthma development.     

Allergen avoidance in the secondary and tertiary prevention of allergic diseases: does it work?

Although allergen avoidance is widely recommended as part of a secondary and tertiary prevention strategy for allergic diseases, a clear-cut demonstration of its effectiveness is still lacking. Ongoing observational secondary prevention cohorts show that sensitisation to mite can be prevented in the short term by allergen avoidance measures, but further follow-up of these children is needed to show if this effect can be sustained, as well as to ascertain its impact on allergic disease. More well-designed trials are still required before we can give any conclusive advice to our patients. Considering the management of allergy, current evidence suggests that interventions in children (either single or multifaceted) may be associated with some beneficial effect on asthma control, but no conclusive evidence exists regarding rhinitis or eczema. Conversely, there is little evidence to support the recommendation of allergen avoidance methods in adults with asthma and rhinitis. There is a need for an adequately designed trial assessing the effects of a multifaceted intervention in this age group.     

IL-33 is associated with allergy in children sensitized to the cat

BackgroundSeveral studies suggest that early-life exposure to animal allergens constitutes a relevant risk factor for the development of allergic sensitization.ObjectivesThe aim of the present study was to determine the role of interleukin-33 in children sensitive to cat allergen with allergic rhinitis and/or asthma.MethodsThe study included 51 children aged 5–18 years, both sexes, allergic to cats. Sensitization to cat allergen was confirmed by skin prick tests or specific IgE. Children were evaluated for the presence of bronchial asthma, atopic dermatitis, allergic rhinitis. A questionnaire evaluating the occurrence of allergic symptoms in children after contact with the cat and dog was performed. Mothers completed a questionnaire regarding cat exposure: during pregnancy and having a cat at home. A blood sample was taken from all children to measure the level of IL-33 in the serum.ResultsKeeping a cat in the home, once in the past, or having a cat in the home during the mother’s pregnancy, revealed a statistically significant relationship with IL-33 levels in the studied patients. Also, daily contact with a cat during pregnancy affected the level of IL-33. Higher levels of IL-33 were shown in people with hypersensitivity to cat and pollen allergens and cat and other animals. In patients with bronchial asthma higher levels of IL-33 were found than in patients without bronchial asthma.ConclusionsIncreased serum levels of IL-33 is related with keeping cats during pregnancy and in early childhood and can be associated with the development of asthma in children.     

Effects of alcohol consumption on the allergen-specific immune response in mice

Background:  There is evidence that chronic alcohol consumption impairs the T-helper 1 (Th1) lymphocyte-regulated cell-mediated immune response possibly favoring a Th2 deviation of the immune response. Moreover, a few epidemiological studies have linked alcohol consumption to allergen-specific IgE sensitization.
Objective:  To investigate the effects of alcohol consumption on the allergen-specific immune response in mice.
Methods:  BALB/cJBomTac mice were immunized intraperitoneally with ovalbumin (OVA) using a low dose sensitization protocol. Throughout the experiment, mice were kept on isocalorical liquid diets containing 0 to 6.2% ethanol. Evaluation of immunomodulatory effects of ethanol was based on measurements of total serum IgE, as well as OVA-specific IgE, IgG1, and IgG2a. Furthermore, levels of OVA-induced interleukin (IL)-4 and interferon- γ were determined in ex vivo splenocyte cultures.
Results:  Alcohol intake decreased the level of OVA-specific IgG2a in a dose-dependent manner, whereas high levels of alcohol markedly increased the level of total IgE, but not OVA-specific IgE. Th1 suppression was supported by the cytokine profile.
Conclusions:  Alcohol consumption induced a marked decrease in markers of the Th1-type allergen-specific immune response and an increase in total serum IgE. In this model, there was no effect of alcohol on OVA-specific IgE. Studies using other routes of immunization may be warranted.     

Omalizumab versus Mepolizumab as add-on therapy in asthma patients not well controlled on at least an inhaled corticosteroid: A network meta-analysis

Objective: The purpose of this study is to examine the comparative efficacy of Omalizumab (OMA) and Mepolizumab (Mepo) in the treatment of severe asthma by performing a network meta-analysis. Method: Data Sources: A systematic review of the literature was performed through four databases from their inception to February 2016. Study Selections: Randomized control trials and cohort studies were considered if they addressed the individual efficacy of OMA and Mepo in the treatment of asthma that was not well controlled on inhaled corticosteroids (ICSs) with or without other agents. Results: OMA was significantly better than Mepo in improving the Asthma Quality of Life Questionnaire with a mean difference of 0.38 and a confidence interval of (0.21–0.55), p < 0.0001, without reaching the minimal clinically important difference of 0.5. No significant difference was seen in Asthma Control Questionnaire, forced expiratory volume in second 1 (FEV1), and Peak Expiratory Flow Rate (PEFR) improvement from baseline. Both medications were successful in reducing the calculated annualized rates of asthma exacerbations (AEs) vs placebo by approximately 50%. The heterogeneity score for the different comparisons were elevated except for the PEFR. Conclusion: When compared indirectly via a network meta-analysis, the efficacy of OMA and Mepo was similar in the treatment of asthma that was not well controlled on at least high-dose ICS. The high heterogeneity observed and the different selection criteria for the use of the two drugs do not permit us to make any definitive recommendations for the preferential use of OMA vs Mepo in the patient populations studied. However, the current data do not suggest any major differences in efficacy.     

Identification of peroxidase-1 and beta-glucosidase as cross-reactive wheat allergens in grass pollen-related wheat allergy

BackgroundSome patients with wheat-dependent exercise-induced anaphylaxis (WDEIA) or wheat allergy showed negative ω-5 gliadin-specific IgE test and high level of grass pollen-specific IgE. It was presumed that these patients developed allergic reaction upon cross-reaction of their IgE antibodies raised against grass pollen allergens to wheat allergens. This study aimed to clarify clinical characteristics and wheat allergens of this phenotype of WDEIA/wheat allergy, which were tentatively diagnosed as grass pollen-related wheat allergy (GPWA).MethodsA total of six patients with GPWA were enrolled, and controls were 17 patients with grass pollen allergy but no episode of wheat allergy, and 29 patients with other wheat allergies: 18 with conventional WDEIA and 11 with hydrolyzed wheat protein allergy. Sensitization to wheat proteins was determined by basophil activation test (BAT). IgE-binding proteins in wheat flour were identified by immunoblotting followed by mass spectrometry. Wheat allergen-specific IgE tests were established by CAP-FEIA system.ResultsAll the six patients with GPWA were sensitized to water-soluble wheat proteins in BAT and IgE-immunoblotting, and peroxidase-1 (35 kDa) and beta-glucosidase (60 kDa) were identified as specific IgE-binding wheat proteins. The binding of patient IgE to these proteins was inhibited by pre-incubation of patient sera with grass pollen. The peroxidase-1- and beta-glucosidase-specific IgE tests identified three and four of six patients with GPWA, respectively, but only two of 29 controls, indicating high specificity of these tests.ConclusionsPeroxidase-1 and beta-glucosidase are specific wheat allergens for GPWA among grass pollen allergy and other types of wheat-induced food allergies.     

Prevalence of over-/misdiagnosis of asthma in patients referred to an allergy clinic

Objective: Increasing asthma incidence may be due to an overall increase in asthma awareness by physicians, potentially resulting in overdiagnosis. One of the unique features of asthma is bronchial hyperresponsiveness, which can be assessed by methacholine bronchial challenge (MBC). Overdiagnosis may result in over- or mistreatment. The aims of this study were to describe the prevalence of the over-/misdiagnosis of asthma and the use of anti-asthmatic drugs in patients with asthma-like symptoms who had not yet undergone a respiratory function assessment to confirm the diagnosis of asthma. Methods: This was a retrospective study analyzing all MBCs performed by our Outpatient Allergy Clinic in a two-year period to confirm/exclude the diagnosis of asthma in patients referred by general practitioners and complaining of asthma-like symptoms. Anti-asthmatic medications used by the patients until the MBC date were recorded. Results: 43.8% of the reviewed MBCs were positive and 37.4% of the patients with a positive MBC were previously taking anti-asthmatic drugs (568.8?±?76.4?mcg mean beclomethasone equivalents), compared to 51.2% of those patients with a negative MBC (464.8?±?57.8?mcg). No differences were found in the daily doses of inhaled corticosteroids or other anti-asthmatic drugs, or in the duration of treatment before the assessment of bronchial hyperresponsiveness. Conclusions: A sizeable percentage of subjects who reported physician-diagnosed asthma had a negative MBC. Nevertheless, a greater proportion of negative MBC patients were taking anti-asthmatic drugs compared to those with a confirmed diagnosis of asthma, illustrating that the overdiagnosis of asthma may lead to over- and mistreatment of respiratory symptoms.     

Undergraduate allergy teaching in a UK medical school: mapping and assessment of an undergraduate curriculum.

BACKGROUND: Concerns have been expressed by patient and professional bodies, and the UK Parliamentary Health Select Committee, about the poor standard of allergy teaching in UK medical schools. It is argued that this deficiency is an important contributing factor to the generally poor quality of care experienced by patients with allergic disorders. Allergy services are currently being reviewed by the Scottish Executive and Department of Health for England. OBJECTIVE: To describe and map the teaching of allergy-related topics in the formal undergraduate curriculum of a UK medical school. METHODS: We undertook a systematic analysis of learning objectives and other electronic documentation of modules taught during the five years of undergraduate medical training at the University of Edinburgh. RESULTS: Allergy and allergy-related topics are mentioned within the learning objectives of 11 (26%) of the 43 modules in the five-year MBChB curriculum. Our overall assessment reveals significant gaps in the described curriculum regarding allergy-related topics. CONCLUSION: Although formal teaching on allergic disorders has been identified in a number of modules throughout the five years, it is not comprehensively described in the course documentation and significant gaps exist. We accept that the delivered curriculum may not be captured by the level of detail present in the learning objectives and recommend that further mapping and triangulation is undertaken through student focus groups and information gathering from teaching staff. We also recommend that in the absence of informal and clinical attachment opportunities in allergic disorders, the stated learning objectives be developed into a coherent vertical element throughout the medical curriculum. This, together with an advocate and suitable assessment, would increase the impact of allergy training on students and emphasise the knowledge and skills required to deliver high quality allergy care.     

Probiotics function and modulation of the immune system in allergic diseases

Allergic diseases have been a global problem over the past few decades. The effect of allergic diseases on healthcare systems and society is generally remarkable and is considered as one of the most common causes of chronic and hospitalized disease. The functional ability of probiotics to modulate the innate/acquired immune system leads to the initiation of mucosal/systemic immune responses. Gut microbiota plays a beneficial role in food digestion, development of the immune system, control/growth of the intestinal epithelial cells and their differentiation. Prescribing probiotics causes a significant change in the intestinal microflora and modulates cytokine secretion, including networks of genes, TLRs, signaling molecules and increased intestinal IgA responses. The modulation of the Th1/Th2 balance is done by probiotics, which suppress Th2 responses with shifts to Th1 and thereby prevent allergies. In general, probiotics are associated with a decrease in inflammation by increasing butyrate production and induction of tolerance with an increase in the ratio of cytokines such as IL-4, IL-10/IFN-γ, Treg/TGF-β, reducing serum eosinophil levels and the expression of metalloproteinase-9 which contribute to the improvement of the allergic disease’s symptoms. Finally, it can be said that the therapeutic approach to immunotherapy and the reduction of the risk of side effects in the treatment of allergic diseases is the first priority of treatment and the final approach that completes the first priority in maintaining the condition and sustainability of the tolerance along with the recovery of the individual     

High-dose inhaled corticosteroids and add-on therapy use in adults with asthma in the UK in 2003: an observational study.

AIMS: To quantify use of high dose inhaled corticosteroids (ICS) and add-on therapy in adults, and children aged 12 and over, in the community. METHODS: Cross-sectional observational survey of UK general practice prescribing records from July 2002 to June 2003 utilising the Doctors Independent Network clinical database. RESULTS: 30,895 patients aged 12 and over were treated for asthma with inhaled corticosteroids, with a quantifiable daily dose recommendation in 22,027 cases. Twenty-seven percent (95% Confidence Intervals 26-28%) were prescribed 'high-dose' ICS (>800 mcg/day beclomethasone or equivalent). Of these, 32% (31-33%) were not currently prescribed add-on therapy (long acting B2 agonists, leukotriene antagonists, theophylines), and most of these (84%, 82-86%) had never received a prior trial of add-on therapy. CONCLUSIONS: High dose ICS therapy was commonly prescribed to people with asthma, frequently without co-prescribed add-on therapy. Many adults with more severe asthma may be receiving treatment that does not accord with current evidence of best practice.     

The basophil activation test in the diagnosis of anaesthesia-related allergy

This review intends to summarise on the application of the basophil activation test (BAT) in the diagnostic management of anaesthesia-related allergy. The BAT relies upon flow cytometric quantification of alterations of particular basophilic activation markers. In the context of anaesthesia-related allergy the technique has been applied and proven reliable to diagnose IgE-mediated allergy from drugs (e.g., neuromuscular blocking agents, β-lactam antibiotics), natural rubber latex, chlorhexidine, plasma expanders and dyes. Moreover, the technique has proven to be complementary to skin tests in the assessment of cross-reactivity and tailoring safe alternative regimens for future anaesthesia.     

Clinical efficacy of probiotic Bifidobacterium longum for the treatment of symptoms of Japanese cedar pollen allergy in subjects evaluated in an environmental exposure unit.

BACKGROUND: Japanese cedar pollinosis (JCPsis) affects nearly one in six Japanese. Oral administration of Bifidobacterium longum BB536 has been shown to be effective in relieving JCPsis symptoms during the pollen season. METHODS: This double- two-way crossover study was designed to evaluate the efficacy of BB536 on reducing symptoms in JCPsis patients exposed to Japanese cedar pollen (JCP) in an environmental exposure unit (EEU) outside of the normal JCP season. After a 1-week run-in period, subjects (n=24) were randomly allocated to receive BB536 powder (approximately 5x1010) or placebo twice a day for 4 weeks. After a 2-week washout period, subjects were crossed over to another 4 weeks of intake. At the end of each intake period, subjects received controlled JCP exposure for 4 hours in the EEU. Symptoms were self-rated 30 minutes before and every 30 minutes during the exposures. From the first day of exposure through the next 5 successive days, participants self-rated their delayed symptoms and medication uses. Blood samples were taken before the exposures. The mean JCP levels for exposures were 6500 to 7000 grains/m3 air. RESULTS: In comparison with placebo, BB536 intake significantly reduced the ocular symptom scores during JCP exposures. Evaluating delayed symptoms after exposures indicated that scores for disruption of normal activities were significantly lower in the BB536 group compared with the placebo group. Prevalence of medication use was markedly reduced by BB536 intake. CONCLUSIONS: These results suggest the potential beneficial effect of BB536 in relieving symptoms of JCP allergy.     

肠道菌群在过敏性支气管哮喘发生和发展中的作用

过敏性支气管哮喘(简称哮喘)是临床上最常见的过敏性疾病之一,主要与免疫紊乱相关.随着“卫生假说”的提出以及微生态学的发展,近年来肠道正常菌群在过敏性哮喘发生、发展中所发挥的作用逐渐为人们所重视.人们在肠道菌群与免疫调节、菌群失调与哮喘发病风险以及利用微生态制剂预防、治疗哮喘等多方面进行了研究,为治疗并预防哮喘开辟了新的空间.     

吸入利多卡因治疗支气管哮喘的可行性探讨

目的　通过观察原有治疗基础上单次吸入一定剂量利多卡因对支气管哮喘患者第 1秒用力呼气量 (FEV1 )和峰值呼气流速 (PEF)的影响 ,探讨吸入利多卡因治疗支气管哮喘的可行性。方法　对 2 0例非急性发作期哮喘患者维持原治疗方案不变 ,分两次随机、双盲雾化吸入 5ml生理盐水和 5ml2 %利多卡因 ( 10 0mg) ,分别测定雾化吸入前 (基础值 )和吸入后 5、10、2 0、3 0、45、60min时的FEV1 和PEF。结果　雾化吸入NS和利多卡因后 10min内平均FEV1 和PEF均较基础值轻度下降 ,平均改变率 ( %基础值 )在不同处理因素间比较差异均无显著性。吸入利多卡因 45～ 60min后FEV1 和PEF有较大幅度升高 ,最高改变率 ( x±s)分别为 ( 6.2± 6.2 ) %和 ( 5 .8± 3 .8) %,而吸入NS后仅略有升高 ,两者比较差异有非常显著性 (P均 <0 .0 1)。吸入利多卡因后 45 %患者FEV1 、PEF升高 >7%,其发生率与吸入生理盐水比较差异有非常显著性 (P <0 .0 1)。结论　哮喘患者在原有治疗基础上吸入利多卡因安全可行 ,多数仅在吸入后早期出现短暂而轻度的FEV1 、PEF下降 ,2 0～ 60min后FEV1 、PEF比对照组有较明显升高