World Allergy Organization guidelines for prevention of allergy and allergic asthma

Children at risk of anaphylaxis: A mixed-studies systematic review of parents' experiences and information needs

Objective

To explore parents' self-reported experiences and information needs regarding recognition and management of pediatric anaphylaxis.

Methods

We searched Ovid Medline, Ovid PsychInfo, CINAHL Plus, the Cochrane Library, and grey literature to identify primary studies in English or French published since 2000. We used a mixed-method appraisal tool and convergent integrated approach to assess quality and synthesize data, respectively.

Results

43 studies were included (22 quantitative, 19 qualitative, and 2 mixed-method); 77% of studies had high methodological quality. Parents' experiences were categorized as: recognizing an anaphylactic reaction; managing and responding to a reaction; emotional impact of caring for a child at risk of anaphylaxis; and interaction with the health system and healthcare providers. Parents' information needs were categorized into themes relating to: gaps in knowledge and information; type of information desired; information sources; and information delivery format.

Conclusion

Negative emotional experiences and a general lack of information were commonly reported by parents of included studies. Provision of relevant and comprehensible information may help parents to make informed decisions and manage reactions promptly.

Innovation

The findings of this review are guiding the development of an innovative knowledge translation tool (KT) as part of a larger initiative of developing a suite of parent-focused KT tools for acute childhood conditions.

A recombinant Artemisia vulgaris pollen adjuvanted Art v 1 protein-based vaccine treats allergic rhinitis and bronchial asthma using pre- and co-seasonal ultrashort immunotherapy regimens in sensitized mice

Allergic rhinitis is an important risk factor for bronchial asthma. Allergen-specific immunotherapy (ASIT) is the gold standard for treatment of allergic rhinitis, conjunctivitis, and asthma. A disadvantage of current ASIT methods is the length of therapy which requires numerous allergen administrations. The success of ASIT is determined by its schedule, which, depending on the vaccine and type of allergy, can be pre-seasonal (before the allergy season begins), combined pre/co-seasonal (during the allergy season) etc. The aim of the present study was to evaluate a vaccine based on recombinant Artemisia vulgaris pollen major Art v 1 protein formulated with ISA-51 adjuvant for therapy of allergic rhinitis and bronchial asthma in Artemisia-sensitized mice in an ultrashort (4 subcutaneous injections at weekly intervals) pre- and co-seasonal ASIT regimen. To simulate co-seasonal ASIT in mice, mice were regularly challenged with intranasal and nebulized Artemisia vulgaris pollen extract at the same time as receiving subcutaneous ASIT. For comparison, we used a previous Art v 1 protein vaccine formulated with SWE adjuvant, which in this study was modified by adding CpG oligonucleotide (Th1-biasing synthetic toll-like receptor 9 agonist), and a commercial vaccine containing a modified Artemisia vulgaris extract with aluminum hydroxide adjuvant. The therapeutic potential of Art v 1 based vaccine formulations with different ASIT regimens was evaluated in high and low (10 times lower) dose regimens. The ISA-51-adjuvanted vaccine formulations were the only ones among those studied in the ultrashort pre- and co-seasonal ASIT regimens to provide significant reduction in both signs of allergic rhinitis and bronchial asthma in sensitized mice (vs. positive control). In the ISA-51 adjuvanted group, immune response polarization toward Th1/Treg was observed in pre-seasonal ASIT, as reflected in a significant decrease in the serum level of total and Art v 1-specific IgE and increased ratios of allergen-specific IgG2a/IgG1 and IFN-γ/IL-4. The high dose SWE-CpG-adjuvanted vaccine had similar efficacy to the ISA-51 adjuvanted groups whereas the commercial vaccine showed significantly less effectiveness. The findings support further preclinical safety studies of the Art v 1-based vaccine formulated with ISA-51 adjuvant.

Neural networks for increased accuracy of allergenic pollen monitoring

Monitoring of airborne pollen concentrations provides an important source of information for the globally increasing number of hay fever patients. Airborne pollen is traditionally counted under the microscope, but with the latest developments in image recognition methods, automating this process has become feasible. A challenge that persists, however, is that many pollen grains cannot be distinguished beyond the genus or family level using a microscope. Here, we assess the use of Convolutional Neural Networks (CNNs) to increase taxonomic accuracy for airborne pollen. As a case study we use the nettle family (Urticaceae), which contains two main genera (Urtica and Parietaria) common in European landscapes which pollen cannot be separated by trained specialists. While pollen from Urtica species has very low allergenic relevance, pollen from several species of Parietaria is severely allergenic. We collect pollen from both fresh as well as from herbarium specimens and use these without the often used acetolysis step to train the CNN model. The models show that unacetolyzed Urticaceae pollen grains can be distinguished with > 98% accuracy. We then apply our model on before unseen Urticaceae pollen collected from aerobiological samples and show that the genera can be confidently distinguished, despite the more challenging input images that are often overlain by debris. Our method can also be applied to other pollen families in the future and will thus help to make allergenic pollen monitoring more specific.

IgE Ratio in Tears: A Predictive Tool of Ocular Allergic Inflammation

PURPOSE

To demonstrate the tear IgE (measured/exuded) ratio (R) as a useful biological marker of ocular allergy in order to distinguish severe from less severe inflammatory status.

METHODS

Tear samples and sera from 78 ocular allergy patients and 19 control subjects were analyzed. Total IgE and albumin were measured for calculating the tear IgE-R defining two subgroups (SG) of samples: R ≥ 4-SG and R < 4-SG. Eosinophil cationic protein, Th1 and Th2 cytokines (IFN-γ, IL-4, -5, -6, -8 and -10) and protein electrophoretic profiles were also investigated in tears.

RESULTS

The R < 4-SG compared to the R ≥ 4-SG shows higher levels of tear albumin, eosinophil cationic protein, and Th1 and Th2 cytokines. Moreover, each subgroup presents a specific protein profile.

CONCLUSION

This study showed that an IgE-R lower than four must be carefully interpreted as a warning sign of a severe inflammatory context and should be also associated with an exploration of immunological profile.

Concomitant suppression of TH2 and TH17 cell responses in allergic asthma by targeting retinoic acid receptor-related orphan receptor γt

BACKGROUND

Allergic asthma is a heterogeneous chronic inflammatory disease of the airways with a massive infiltration of eosinophils or neutrophils mediated by allergen-specific T_H2 and T_H17 cells, respectively. Therefore successful treatment of allergic asthma will require suppression of both T_H2 and T_H17 cells.

OBJECTIVE

We sought to investigate the role of the T_H17 cell pathway in regulating T_H2 cell responses in allergic asthma.

METHODS

Allergic asthma was induced by intranasal challenge with proteinase allergens in C57BL/6, Il17a^-/-Il17f^-/-, and retinoic acid receptor-related orphan receptor γt (RORγt)^gfp/gfp mice. A pharmacologic RORγt inhibitor was used to evaluate its preventive and therapeutic effects in allergic asthma. Characteristics of allergic airway inflammation were analyzed by using flow cytometry, histology, quantitative real-time PCR, and ELISA. Mixed bone marrow chimeric mice, fate mapping analysis, short hairpin RNA transduction, and in vitro T-cell differentiation were used for mechanistic studies.

RESULTS

Mice deficient in IL-17A and IL-17F, as well as RORγt, exhibited a significant reduction not only in T_H17 cell responses but also in T_H2 cell responses in an animal model of allergic asthma. Similarly, mice treated with an RORγt inhibitor had significantly diminished T_H17 and T_H2 cell responses, leading to reduced neutrophil and eosinophil numbers in the airway. RORγt-deficient T cells were intrinsically defective in differentiating into T_H2 cells and expressed increased levels of B-cell lymphoma 6 (Bcl6). Bcl6 knockdown resulted in a remarkable restoration of T_H2 cell differentiation in RORγt-deficient T cells. Blockade of RORγt also significantly hampered the differentiation of human T_H2 and T_H17 cells from naive CD4⁺ T cells.

CONCLUSION

RORγt in T cells is required for optimal T_H2 cell differentiation by suppressing Bcl6 expression; this finding suggests that targeting RORγt might be a promising approach for the treatment of allergic asthma by concomitantly suppressing T_H17 and T_H2 cell responses in the airway.

Detection of allergen sources in the homes of sensitized children

OBJECTIVE

To identify the presence of environmental factors linked to the onset of allergies and asthma in the homes of children participating in an early detection program that were identified with sensitivity to common allergens in the region of Sonora, Mexico.

METHODS

A walkthrough assessment was carried out in the homes of sensitized children; the research tools were the questionnaire and environmental checklist proposed by the Lowell Healthy Homes Program of the University of Massachusetts-Lowell.

RESULTS

The results showed the presence of environmental allergen sources, to which most of the children in the study are sensitized, as well as the environmental conditions and habits that determine the quality of the indoor air of the households, were both related to triggering allergies and asthma in this population. A statistically significant association was found between the visual observation of dust inside homes and the sensitivity of children to dust mites.

CONCLUSIONS

Dust found inside the home was the most relevant environmental factor related to positive cases of IgE in children. Early detection of allergies in children in the study and the methodology used in this investigation provided a useful framework for the design of plans and intervention alternatives in these homes to prevent the development of allergies and asthma panorama. These plans should be designed with a multidisciplinary approach to impact social, environmental and economic benefits in the family, improving the living conditions of the study population and contributing to the sustainable development goals of the United Nations for 2030.

Prevalence of asthma in Saudi adults: findings from a national household survey, 2013

BACKGROUND

There are not enough data on the epidemiology of asthma in the Kingdom of Saudi Arabia (KSA). We analyzed data from a national household survey conducted in KSA in 2013 to estimate prevalence, associated risk factors and control measurements of asthma.

METHODS

The Saudi Health Interview Survey was a cross-sectional national multistage survey of 10,735 individuals aged 15 years or older. The survey included a detailed household questionnaire and a physical exam. We used self-reported clinical diagnosis of asthma to assess prevalence of asthma.

RESULTS

The prevalence of asthma in KSA was 4.05 % (95 % confidence interval [CI]: 3.54-4.62 %). Asthma was less frequent in individuals with higher education but higher in former smokers and obese individuals. Around 76.7 % of asthma patients (95 % CI: 70.6-82.0 %) experienced an asthmatic attack, and 61.6 % (95 % CI: 54.4-68.4 %) visited a hospital/emergency room because of asthma during the past year. Asthma attack was less frequent in older patients (odds ratio [OR] = 0.78, 95 %CI: 0.59-0.96 for each decade of life). Current use of medication for asthma was highly associated with asthma attacks (OR = 9.14, 95 % CI: 3.29-25.38). Asthma attack was also more frequent in individuals who were exposed to secondhand smoking (OR = 2.17, 95 %CI: 1.05-4.45) and those who were obese (OR = 3.01, 95 %CI: 1.34-6.78).

CONCLUSION

Saudi Arabia has a relatively low prevalence of diagnosed asthma; however, many of the patients with known asthma do not have it under good control. Our study calls for programs to inform patients about the importance and proper means of controlling their condition. Implementing and monitoring of clinical guidelines can also help to improve asthma control among patients as well as identify undiagnosed cases.

Maternal prenatal and/or postnatal n-3 long chain polyunsaturated fatty acids (LCPUFA) supplementation for preventing allergies in early childhood

BACKGROUND

Allergies have become more prevalent globally over the last 20 years. Dietary consumption of n-3 (or omega 3) long chain polyunsaturated fatty acids (LCPUFA) has declined over the same period of time. This, together with the known role of n-3 LCPUFA in inhibiting inflammation, has resulted in speculation that n-3 LCPUFA may prevent allergy development. Dietary n-3 fatty acids supplements may change the developing immune system of the newborn before allergic responses are established, particularly for those with a genetic predisposition to the production of the immunoglobulin E (IgE) antibody. Individuals with IgE-mediated allergies have both the signs and symptoms of the allergic disease and a positive skin prick test (SPT) to the allergen.

OBJECTIVES

To assess the effect of n-3 LCPUFA supplementation in pregnant and/or breastfeeding women on allergy outcomes (food allergy, atopic dermatitis (eczema), allergic rhinitis (hay fever) and asthma/wheeze) in their children.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (6 August 2014), PubMed (1966 to 01 August 2014), CINAHL via EBSCOhost (1984 to 01 August 2014), Scopus (1995 to 01 August 2014), Web of Knowledge (1864 to 01 August 2014) and ClinicalTrials.gov (01 August 2014) and reference lists of retrieved studies.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) evaluating the effect of n-3 LCPUFA supplementation of pregnant and/or lactating women (compared with placebo or no treatment) on allergy outcomes of the infants or children. Trials using a cross-over design and trials examining biochemical outcomes only were not eligible for inclusion.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed eligibility and trial quality and performed data extraction. Where the review authors were also investigators on trials selected, an independent reviewer assessed trial quality and performed data extraction.

MAIN RESULTS

Eight trials involving 3366 women and their 3175 children were included in the review. In these trials, women were supplemented with n-3 LCPUFA during pregnancy (five trials), lactation (two trials) or both pregnancy and lactation (one trial). All trials randomly allocated women to either a n-3 LCPUFA supplement or a control group. The risk of bias varied across the eight included trials in this review with only two trials with a low risk of selection, performance and attrition bias.N-3 LCPUFA supplementation showed a clear reduction in the primary outcome of any allergy (medically diagnosed IgE mediated) in children aged 12 to 36 months (risk ratio (RR) 0.66, 95% confidence interval (CI) 0.44 to 0.98; two RCTs; 823 children), but not beyond 36 months (RR 0.86, 95% CI 0.61 to 1.20; one RCT, 706 children). For any allergy (medically diagnosed IgE mediated and/or parental report), no clear differences were seen in children either at 12 to 36 months (RR 0.89, 95% CI 0.71 to 1.11; two RCTs, 823 children) or beyond 36 months of age (RR 0.96, 95% CI 0.84 to 1.09; three RCTs, 1765 children).For the secondary outcomes of specific allergies there were no clear differences for food allergies at 12 to 36 months and beyond 36 months, but a clear reduction was seen for children in their first 12 months with n-3 LCPUFA (both for medically diagnosed IgE mediated and medically diagnosed IgE mediated and/or parental report). There was a clear reduction in medically diagnosed IgE-mediated eczema with n-3 LCPUFA for children 12 to 36 months of age, but not at any other time point for both medically diagnosed IgE mediated and medically diagnosed IgE mediated and/or parental report. No clear differences for allergic rhinitis or asthma/wheeze were seen at any time point for both medically diagnosed IgE mediated, and medically diagnosed IgE mediated and/or parental report.There was a clear reduction in children's sensitisation to egg and sensitisation to any allergen between 12 to 36 months of age when mothers were supplemented with n-3 LCPUFA.In terms of safety for the mother and child, n-3 LCPUFA supplementation during pregnancy did not show increased risk of postpartum haemorrhage or early childhood infections.

AUTHORS' CONCLUSIONS

Overall, there is limited evidence to support maternal n-3 LCPUFA supplementation during pregnancy and/or lactation for reducing allergic disease in children. Few differences in childhood allergic disease were seen between women who were supplemented with n-3 LCPUFA and those who were not.

Associations between selected allergens, phthalates, nicotine, polycyclic aromatic hydrocarbons, and bedroom ventilation and clinically confirmed asthma, rhinoconjunctivitis, and atopic dermatitis in preschool children

Previous studies, often using data from questionnaires, have reported associations between various characteristics of indoor environments and allergic disease. The aim of this study has been to investigate possible associations between objectively assessed indoor environmental factors and clinically confirmed asthma, rhinoconjunctivitis, and atopic dermatitis. The study is a cross-sectional case-control study of 500 children aged 3-5 years from Odense, Denmark. The 200 cases had at least two parentally reported allergic diseases, while the 300 controls were randomly selected from 2835 participating families. A single physician conducted clinical examinations of all 500 children. Children from the initially random control group with clinically confirmed allergic disease were subsequently excluded from the control group and admitted in the case group, leaving 242 in the healthy control group. For most children, specific IgE's against various allergens were determined. In parallel, dust samples were collected and air change rates were measured in the children's bedrooms. The dust samples were analyzed for phthalate esters, polycyclic aromatic hydrocarbons (PAH), nicotine, and various allergens. Among children diagnosed with asthma, concentrations of nicotine were higher (P < 0.05) and cat allergens were lower (P < 0.05) compared with the healthy controls; air change rates were lower for those sensitized (specific IgE+) compared with those not sensitized (specific IgE-, P < 0.05); and dust mite allergens were higher for specific IgE+ cases compared with healthy controls (P < 0.05). When disease status was based solely on questionnaire responses (as opposed to physician diagnosis), significant associations were found between di(2-ethylhexyl) phthalate (DEHP) and dog allergens in dust and current wheeze.

Should we encourage allergen immunotherapy during pregnancy?

Primary prevention of allergy is a laudable goal, but one that has unfortunately proven difficult to achieve. Many different strategies have been reported to date, but unequivocal supporting data for any single strategy does not exist. Any successful strategy must lead to immunomodulation and must be encountered very early on life, likely in utero. Reports of early bacterial and farm animal exposures lend supportive data to the concept of immune regulation via early fetal exposure, howeve attempts at clinical applications of this, such as probiotics has not been completely successful. One practical, clinical method for achieving a similar immune modulation to these exposures would be providing atopic women with allergy immunotherapy while pregnant (or perhaps even preconception). Allergy immunotherapy is associated with favorable immune modulation and some data suggest that these changes if produced in mother can influence the atopic status of offspring.

The effect of biomass fuel exposure on the prevalence of asthma in adults in India - review of current evidence

INTRODUCTION

The combustion of biomass fuels is a major source of respiratory disease among individuals in the developing world. Over two million people world-wide rely on biomass fuels to supply their household energy needs with an estimated 1.6 million deaths annually being attributable to biomass smoke exposure. As a developing country, India relies heavily on the use of solid fuels as a source of energy. These materials supply 75% of the country's domestic energy need and are attributed as the cause of over 600 000 deaths annually. Diseases such as chronic bronchitis and acute lower respiratory tract infections are strongly correlated to biomass smoke exposure. While not as strongly correlated, accumulating evidence suggests that asthma prevalence may be related to solid fuel smoke.

METHODS

This review examines the current literature linking biomass smoke exposure to the reporting of asthma symptoms. A PubMed search was performed using key terms biomass, asthma, India and respiratory disease. Preference was given to recent articles that surveyed the adult population within India.

RESULTS

The reviewed articles showed an increased odds ratio for reporting a diagnosis of asthma or symptoms consistent with asthma following biomass smoke exposure. While the literature supports a strong association between household air pollution and the development of chronic bronchitis and acute lower respiratory tract infections in India, this review establishes a more firm relationship between reported asthma symptoms and biomass smoke exposure.

CONCLUSION

The exposure to biomass fuel smoke results in respiratory diseases in developing countries. Among these diseases, asthma appears to be a preventable pulmonary pathology that is associated with household air pollution. Measures to reduce exposure may decrease the burden of disease which could help advance social and economic progress in these nations. Further research and out-reach efforts are needed to reduce the total burden of lung diseases, including asthma, across the developing world. This reduction could save millions of dollars annually and lower morbidity and mortality in the affected populations.

Methodological rigor and reporting of clinical practice guidelines in patients with allergic rhinitis: QuGAR study

BACKGROUND

There are several clinical practice guidelines about the management of allergic rhinitis (AR) being used by clinicians.

OBJECTIVE

We sought to assess the methodological rigor and transparency of reporting of clinical practice guidelines for the management of AR.

METHODS

We systematically searched MEDLINE, the TRIP database, and professional society Web sites for all guidelines about the management of AR published in English after the year 2000. Four reviewers independently assessed the rigor of development and reporting of included guidelines using the Appraisal of Guidelines for Research and Evaluation II instrument.

RESULTS

Our search revealed 432 records, of which 34 full-text articles were assessed for eligibility and 10 fulfilled inclusion criteria. Overall methodological rigor and reporting of guidelines varied from fulfilling most of the Appraisal of Guidelines for Research and Evaluation II criteria to almost none. Across all guidelines, the best reported domain was clarity of presentation, and the least rigorously addressed domain was applicability of guidelines. Agreement beyond chance among the 4 appraisers was fair.

CONCLUSIONS

Guideline users should be aware of the difference in the rigor of development and quality of reporting of guidelines about the management of AR. They should choose higher-quality guidelines to use in their practice and teaching. For most reviewed guidelines, there is room for improvement, particularly in the domains of applicability and implementation.

Prebiotics in infants for prevention of allergy

BACKGROUND

Prebiotics (commonly oligosaccharides) added to infant feeds have the potential to prevent sensitisation of infants to dietary allergens.

OBJECTIVES

To determine the effect of prebiotic given to infants for the prevention of allergy.

SEARCH METHODS

We performed an updated search in August 2012 of the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2012, Issue 8), MEDLINE, EMBASE, conference proceedings, citations, expert informants and clinical trials registries.

SELECTION CRITERIA

Randomised and quasi-randomised controlled trials that compared the use of a prebiotic to no prebiotic, or a specific prebiotic compared to a different prebiotic in infants for prevention of allergy.

DATA COLLECTION AND ANALYSIS

Assessment of trial quality, data extraction and synthesis of data were performed using the standard methods of The Cochrane Collaboration.

MAIN RESULTS

The 2012 update identified 13 studies classified as ongoing or awaiting classification (yet to report allergy outcomes). Forty-three studies were excluded, primarily as no allergy data were reported, although none of these enrolled infants were at high risk of allergy. Four studies enrolling 1428 infants were eligible for inclusion. All studies were at high risk of attrition bias. Allergy outcomes were reported from four months to two years of age.Meta-analysis of two studies (226 infants) found no significant difference in infant asthma although significant heterogeneity was found between studies. Meta-analysis of four studies found a significant reduction in eczema (1218 infants, typical risk ratio 0.68, 95% CI 0.48 to 0.97; typical risk difference -0.04, 95% CI -0.07 to -0.00; number needed to treat to benefit (NNTB) 25, 95% CI 14 to > 100; P = 0.03). No statistically significant heterogeneity was found between studies. One study reported no significant difference in urticaria.No statistically significant subgroup differences were found according to infant risk of allergy or type of infant feed. However, individual studies reported a significant reduction in asthma and eczema from supplementation with a mixture of galacto- and fructo-oligosaccharide (GOS/FOS 9:1 ratio) (8 g/L) in infants at high risk of allergy; and in eczema from supplementation with GOS/FOS (9:1) (6.8 g/L) and acidic oligosacccharide (1.2 g/L) in infants not selected for allergy risk.

AUTHORS' CONCLUSIONS

Further research is needed before routine use of prebiotics can be recommended for prevention of allergy in formula fed infants. There is some evidence that a prebiotic supplement added to infant feeds may prevent eczema. It is unclear whether the use of prebiotic should be restricted to infants at high risk of allergy or may have an effect in low risk populations; or whether it may have an effect on other allergic diseases including asthma.

Suppression of allergen-specific IgE in offspring after preconceptional immunisation: maternal, paternal and genetic influences

Immunisation of female mice with the allergen ovalbumin (OVA) during pregnancy reduces the OVA-specific IgE response in adult offspring. To approach primary prevention strategies for allergy, we investigated to what extent genetic, paternal and maternal factors influence this suppressive effect on allergic sensitisation in offspring and investigated the possibility of pregestational immunisation. Maternal allergen immunisation reduced OVA-specific IgE levels in immunised offspring, even after maternal immunisation up to 8 weeks before conception without further allergen exposure. Immunisation of immunodeficient BALB/c severe combined immune deficiency (SCID) dams mated with wild type males did not lead to IgE suppression in offspring, indicating the importance of a functional maternal immune system. Immunisation of male mice before the relevant spermatogenesis did not cause antibody suppression in offspring. OVA-specific IgG1, presumably of maternal origin, was present in naïve offspring only from immunised dams and was associated with suppressed IgE responses after offspring immunisation. The IgE-suppressive effect of maternal immunisation was demonstrated in all three immunocompetent strains tested (NIH/OlaHsd, BALB/cA and C57BL/6 mice). In conclusion, suppression of allergen-specific IgE production in offspring could not be induced by paternal immunisation, and genetic factors were of minor importance. In contrast, we demonstrate the necessity of maternal factors, possibly allergen-specific IgG1, resulting from a functional adaptive immune response, for the IgE-suppressive effect in offspring. These maternal factors could be induced by immunisation of female mice even before conception.

The biodiversity hypothesis and allergic disease: world allergy organization position statement

Biodiversity loss and climate change secondary to human activities are now being associated with various adverse health effects. However, less attention is being paid to the effects of biodiversity loss on environmental and commensal (indigenous) microbiotas. Metagenomic and other studies of healthy and diseased individuals reveal that reduced biodiversity and alterations in the composition of the gut and skin microbiota are associated with various inflammatory conditions, including asthma, allergic and inflammatory bowel diseases (IBD), type1 diabetes, and obesity. Altered indigenous microbiota and the general microbial deprivation characterizing the lifestyle of urban people in affluent countries appear to be risk factors for immune dysregulation and impaired tolerance. The risk is further enhanced by physical inactivity and a western diet poor in fresh fruit and vegetables, which may act in synergy with dysbiosis of the gut flora. Studies of immigrants moving from non-affluent to affluent regions indicate that tolerance mechanisms can rapidly become impaired in microbe-poor environments. The data on microbial deprivation and immune dysfunction as they relate to biodiversity loss are evaluated in this Statement of World Allergy Organization (WAO). We propose that biodiversity, the variability among living organisms from all sources are closely related, at both the macro- and micro-levels. Loss of the macrodiversity is associated with shrinking of the microdiversity, which is associated with alterations of the indigenous microbiota. Data on behavioural means to induce tolerance are outlined and a proposal made for a Global Allergy Plan to prevent and reduce the global allergy burden for affected individuals and the societies in which they live.

Interactions of physical, chemical, and biological weather calling for an integrated approach to assessment, forecasting, and communication of air quality

This article reviews interactions and health impacts of physical, chemical, and biological weather. Interactions and synergistic effects between the three types of weather call for integrated assessment, forecasting, and communication of air quality. Today's air quality legislation falls short of addressing air quality degradation by biological weather, despite increasing evidence for the feasibility of both mitigation and adaptation policy options. In comparison with the existing capabilities for physical and chemical weather, the monitoring of biological weather is lacking stable operational agreements and resources. Furthermore, integrated effects of physical, chemical, and biological weather suggest a critical review of air quality management practices. Additional research is required to improve the coupled modeling of physical, chemical, and biological weather as well as the assessment and communication of integrated air quality. Findings from several recent COST Actions underline the importance of an increased dialog between scientists from the fields of meteorology, air quality, aerobiology, health, and policy makers.

Specific IgE levels to Dermatophagoides pteronyssinus are associated with meteorological factors

BACKGROUND

Dermatophagoides pteronyssinus specific IgE (sIgE) measurement is a major diagnostic test for the detection of sensitization to that allergen.

METHODS

To investigate the effect of climate on the seasonal variations of D.pteronyssinus sIgE, we studied the tests performed in an insular population during a 10-year period. The association with meteorological factors was evaluated with multiple regression analyses.

RESULTS

Of 24,879 tests performed for D. pteronyssinus sIgE, 16,719 (67.2%) were D. pteronyssinus sIgE positive; 24.5% were tested for asthma and 46.07% for rhinitis. D. pteronyssinus sIgE levels showed a seasonal pattern with an annual peak in November. In the multivariate analyses solar radiation (r = -0.94) and relative humidity (r = 0.86) were independent factors associated with D. pteronyssinus sIgE levels. The resulting model could explain 93% (p < 0.001) of D. pteronyssinus sIgE variability.

CONCLUSIONS

Our population showed a seasonal pattern of D. pteronyssinus sIgE explained by relative humidity and solar radiation.

Allergens from Fusarium solani identified by immunoblotting in asthma patients In Iran

We extracted Fusarium solani antigens to evaluate specific anti-F. solani IgE in fifty-one patients with asthma (33 men and 18 women) and in 22 non-atopic healthy subjects (15 men and 7 women). F. solani strains were cultured in Sabouraud glucose agar and subjected to cell disruption using the freeze-and-thaw method. The obtained cytoplasmic extracts were analysed using sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE). Sensitisation to F. solani antigens has been evaluated in asthmatic patients using the immunoblotting assay. The SDS-PAGE identified 29 protein bands in the cytoplasmic extracts of F. solani isolates, with molecular weights ranging from 24 kDa to 112 kDa. Immunoblotting detected specific anti-F. solani IgE antibody in all asthma patients, but not in the control group. The predominant reactive allergens in patients corresponded to the bands with molecular weights of 24 kDa, 58.5 kDa, 64.5 kDa, 69 kDa, 72 kDa, and 97 kDa. Our results suggest that various allergenic components of F. solani may produce symptoms of asthma in susceptible individuals and they call for further research.

Food allergy and allergic gastrointestinal diseases in infants

Food allergy is an adverse immune response to a food allergen, which can affect the gastrointestinal tract, skin and respiratory tract. The manifestations of a food allergy affecting the digestive tract include reflux, vomiting, abdominal pain, diarrhea, and gastrointestinal bleeding. In recent years, more and more attention has been paid to the relationship between food allergy and infantile diarrhea. This paper gives an overview of food allergies, reviews recent advances in understanding the relationship between food allergies and diarrhea-related allergic gastrointestinal diseases, and discusses the diagnosis and treatment of these diseases.

Allergy in children: practical recommendations of the Finnish Allergy Programme 2008-2018 for prevention, diagnosis, and treatment

The Finnish Allergy Programme 2008-2018 is a comprehensive plan intended to reduce the burden of allergies. One basic goal is to increase immunologic tolerance and change attitudes to encourage health instead of medicalizing common and mild allergy symptoms. The main goals can be listed as to: (i) prevent the development of allergic symptoms; (ii) increase tolerance to allergens; (iii) improve diagnostics; (iv) reduce work-related allergies; (v) allocate resources to manage and prevent exacerbations of severe allergies, and (vi) reduce costs caused by allergic diseases. So far, the Allergy Programme has organized 135 educational meetings for healthcare professionals around Finland. These meetings are multidisciplinary meetings gathering together all healthcare professionals working with allergic diseases. Since the start of the program in spring 2008, more than 7000 participants have taken part. Educational material for patient care has been provided on special Web sites/therapeutic portals, which can be accessed by all physicians caring for allergic patients. Local Allergy Working Groups have been created in different parts of Finland. As a part of the Programme, a set of guidelines for child welfare clinics was prepared. Child welfare clinics have a key role in the screening of illnesses and providing advice to families with a symptomatic child. The guidelines aimed to facilitate pattern recognition and clinical decision making for public health nurses and doctors are described in this paper.

Association between asthma and dental caries in the primary dentition of Mexican children

BACKGROUND

Asthma has been associated with a great number of negative health outcomes. This study was undertaken to detect the association between asthma and dental caries in the primary dentition.

METHODS

Data were obtained from a cohort of 1160 Mexican children aged 4-5 years. We used the questionnaire of the International Study of Asthma and Allergies Diseases in Childhood. Asthma was classified according to parents' reports. Caries indexes were measured as the number of decayed (d), missing (m), and filled (f), teeth (t) (dmft) or surfaces (dmfs). Decayed teeth included initial caries in this study. Adjusted odds ratios (adjusted ORs) were determined for asthma using logistic regression model. Gender, sugary products consumption, and oral hygiene habits were utilized as covariates.

RESULTS

The prevalence of dental caries was 17.9% in the 1160 children. Approximately 226 (19.5%) children were identified with asthma. Among them, 166 (73.5%) presented with symptoms during the day and 60 (26.5%) during the day and night. The prevalence of caries in children with asthma was 19.9%; it was higher in children with nocturnal asthma symptoms than in those with asthma symptoms only during the day. Logistic regression model showed that asthma (adjusted OR=1.24; 95% confidence interval [95% CI]=0.84-1.81) was not associated with caries. A significant association was found between nocturnal asthma symptoms (adjusted OR=1.85; 95% CI=1.00-3.44) and dental caries.

CONCLUSIONS

Asthma is not associated with dental caries. Nocturnal asthma symptoms appear to be associated with dental caries in the primary dentition.

Scientific rationale for the Finnish Allergy Programme 2008-2018: emphasis on prevention and endorsing tolerance

In similarity to many other western countries, the burden of allergic diseases in Finland is high. Studies worldwide have shown that an environment rich in microbes in early life reduces the subsequent risk of developing allergic diseases. Along with urbanization, such exposure has dramatically reduced, both in terms of diversity and quantity. Continuous stimulation of the immune system by environmental saprophytes via the skin, respiratory tract and gut appears to be necessary for activation of the regulatory network including regulatory T-cells and dendritic cells. Substantial evidence now shows that the balance between allergy and tolerance is dependent on regulatory T-cells. Tolerance induced by allergen-specific regulatory T-cells appears to be the normal immunological response to allergens in non atopic healthy individuals. Healthy subjects have an intact functional allergen-specific regulatory T-cell response, which in allergic subjects is impaired. Evidence on this exists with respect to atopic dermatitis, contact dermatitis, allergic rhinitis and asthma. Restoration of impaired allergen-specific regulatory T-cell response and tolerance induction has furthermore been demonstrated during allergen-specific subcutaneous and sublingual immunotherapy and is crucial for good therapeutic outcome. However, tolerance can also be strengthened unspecifically by simple means, e.g. by consuming farm milk and spending time in nature. Results so far obtained from animal models indicate that it is possible to restore tolerance by administering the allergen in certain circumstances both locally and systemically. It has become increasingly clear that continuous exposure to microbial antigens as well as allergens in foodstuffs and the environment is decisive, and excessive antigen avoidance can be harmful and weaken or even prevent the development of regulatory mechanisms. Success in the Finnish Asthma Programme was an encouraging example of how it is possible to reduce both the costs and morbidity of asthma. The time, in the wake of the Asthma Programme, is now opportune for a national allergy programme, particularly as in the past few years, fundamentally more essential data on tolerance and its mechanisms have been published. In this review, the scientific rationale for the Finnish Allergy Programme 2008-2018 is outlined. The focus is on tolerance and how to endorse tolerance at the population level.

Prebiotics in infants for prevention of allergic disease and food hypersensitivity

BACKGROUND

The composition of the intestinal microflora may be different in individuals with atopic eczema from those without this condition, and such differences may precede the development of eczema. Prebiotics are nondigestible food components that benefit the host by selectively stimulating the growth or activity of non-pathogenic bacteria in the colon. Prebiotics (commonly oligosaccharides) added to infant feeds have the potential to prevent sensitisation of infants to dietary allergens.

OBJECTIVES

To determine the effect of prebiotics given to infants for the prevention of allergic disease or food hypersensitivity.

SEARCH STRATEGY

This included searches of the Cochrane Central Register of Controlled Trials (Issue 1, 2007), MEDLINE (1966 - February 2007), EMBASE, PREMEDLINE, abstracts of conference proceedings and citations of published articles, and expert informants.

SELECTION CRITERIA

Randomised and quasi-randomised controlled trials that compared the use of a prebiotic to no prebiotic; or the use a specific prebiotic compared to a different prebiotic.

DATA COLLECTION AND ANALYSIS

Assessment of trial quality, data extraction and synthesis of data were performed using standard methods of the Cochrane Neonatal Review Group.

MAIN RESULTS

Seven studies were eligible for inclusion. Only two studies reported an allergic disease outcome for 432 infants. Study quality was reasonable, although Moro 2006 reported 20% post-randomisation losses. Moro 2006 enrolled hydrolysed formula fed infants at high risk of allergy and reported a significant reduction in eczema in infants up to six months of age (RR 0.42, 95% CI 0.21, 0.84). Ziegler 2007 enrolled formula fed infants who were not selected on the basis of risk for allergy and reported no significant difference in eczema up to four months of age (RR 1.62, 95% CI 0.62, 4.26). Meta-analysis of the two studies found no significant difference in eczema, but significant heterogeneity was detected. Differences were potentially attributable to differences in infant risk, prebiotic formulation or measurement of eczema. Analysis of five studies reporting measures of infant growth found no consistent adverse effects.

AUTHORS' CONCLUSIONS

There is insufficient evidence to determine the role of prebiotic supplementation of infant formula for prevention of allergic disease and food hypersensitivity. One small trial of prebiotic oligosaccharides with excess losses reported a reduction in eczema in high risk formula fed infants. Further trials are needed to determine whether this finding persists over a longer period of time, applies to other manifestations of allergic disease, is associated with reductions in allergen sensitisation, and is reproducible.

Probiotics in infants for prevention of allergic disease and food hypersensitivity

BACKGROUND

The composition of the intestinal microflora may be different in individuals with atopic eczema from those without this condition, and such differences may precede the development of eczema. Probiotics are live bacteria that colonize the gastrointestinal tract and provide a health benefit to the host. Probiotics added to infant feeds have the potential to prevent sensitisation of infants to dietary allergens.

OBJECTIVES

To determine the effect of probiotics given to infants for the prevention of allergic disease or food hypersensitivity.

SEARCH STRATEGY

This included searches of the Cochrane Central Register of Controlled Trials (Issue 1, 2007), MEDLINE (1966 - February 2007), EMBASE, PREMEDLINE, abstracts of conference proceedings and citations of published articles, and expert informants.

SELECTION CRITERIA

Randomised and quasi-randomised controlled trials that compare the use of a probiotic to no probiotic; or the use a specific probiotic compared to a different probiotic; or a probiotic with added prebiotic to control.

DATA COLLECTION AND ANALYSIS

Assessment of trial quality, data extraction and synthesis of data were performed using standard methods of the Cochrane Neonatal Review Group.

MAIN RESULTS

Twelve studies were eligible for inclusion. Allergic disease and / or food hypersensitivity outcomes were assessed by 6 studies enrolling 2080 infants, but outcomes for only 1549 infants were reported. Studies generally had adequate randomisation, allocation concealment and blinding of treatment. However, the findings of this review should be treated with caution due to excess losses in patient follow-up (17% to 61%). Meta-analysis of five studies reporting the outcomes of 1477 infants found a significant reduction in infant eczema (typical RR 0.82, 95% CI 0.70, 0.95). However, there was significant and substantial heterogeneity between studies. One study reported that the difference in eczema between groups persisted to 4 years age. When the analysis was restricted to studies reporting atopic eczema (confirmed by skin prick test or specific IgE), the findings were no longer significant (typical RR 0.80, 95% CI 0.62, 1.02). All studies reporting significant benefits used probiotic supplements containing L. rhamnosus and enrolled infants at high risk of allergy. No other benefits were reported for any other allergic disease or food hypersensitivity outcome.

AUTHORS' CONCLUSIONS

There is insufficient evidence to recommend the addition of probiotics to infant feeds for prevention of allergic disease or food hypersensitivity. Although there was a reduction in clinical eczema in infants, this effect was not consistent between studies and caution is advised in view of methodological concerns regarding included studies. Further studies are required to determine whether the findings are reproducible.

Allergic rhinitis and asthma: inflammation in a one-airway condition

Background

Allergic rhinitis and asthma are conditions of airway inflammation that often coexist.

Discussion

In susceptible individuals, exposure of the nose and lungs to allergen elicits early phase and late phase responses. Contact with antigen by mast cells results in their degranulation, the release of selected mediators, and the subsequent recruitment of other inflammatory cell phenotypes. Additional proinflammatory mediators are released, including histamine, prostaglandins, cysteinyl leukotrienes, proteases, and a variety of cytokines, chemokines, and growth factors. Nasal biopsies in allergic rhinitis demonstrate accumulations of mast cells, eosinophils, and basophils in the epithelium and accumulations of eosinophils in the deeper subepithelium (that is, lamina propria). Examination of bronchial tissue, even in mild asthma, shows lymphocytic inflammation enriched by eosinophils. In severe asthma, the predominant pattern of inflammation changes, with increases in the numbers of neutrophils and, in many, an extension of the changes to involve smaller airways (that is, bronchioli). Structural alterations (that is, remodeling) of bronchi in mild asthma include epithelial fragility and thickening of its reticular basement membrane. With increasing severity of asthma there may be increases in airway smooth muscle mass, vascularity, interstitial collagen, and mucus-secreting glands. Remodeling in the nose is less extensive than that of the lower airways, but the epithelial reticular basement membrane may be slightly but significantly thickened.

Conclusion

Inflammation is a key feature of both allergic rhinitis and asthma. There are therefore potential benefits for application of anti-inflammatory strategies that target both these anatomic sites.

Levocetirizine: a review of its use in the management of allergic rhinitis and skin allergies

Levocetirizine (Xyzal) is a selective, potent, oral histamine H(1) receptor antagonist of the latest generation that is licensed for the symptomatic treatment of allergic rhinitis (including persistent allergic rhinitis [PER]) and chronic idiopathic urticaria (CIU). Large, well designed trials indicate that levocetirizine is effective and generally well tolerated in the treatment of allergic rhinitis and CIU. Its pharmacological profile offers many positive aspects: a rapid onset and long duration of antihistaminic effect; rapid absorption and high bioavailability; a low potential for drug interactions; a low volume of distribution; and a lack of effect on cognition, psychomotor function and the cardiovascular system. Allergen challenge chamber studies suggest that levocetirizine has better efficacy than desloratadine, loratadine or fexofenadine. Well controlled, long-term studies with other later-generation H(1) receptor antagonists are required to fully define its clinical profile relative to other agents in this class. Overall, levocetirizine is a valuable addition to the oral H(1) receptor antagonists available for the treatment of allergic rhinitis and as first-line therapy in patients with CIU.

Dietary assessment in children adhering to a food allergen avoidance diet for allergy prevention

OBJECTIVE

The purpose of this investigation was to verify if avoidance of allergenic foods in children adhering to a food allergen avoidance diet from birth was complete and feasible, and whether dietary assessment can be used as a tool in predicting the outcome of double-blind, placebo-controlled food challenges (DBPCFCs).

DESIGN

Children adhering to an allergen avoidance diet from birth underwent DBPCFCs. The investigator-dietician verified whether the elimination was complete, using food frequency questionnaires for common allergenic foods.

SETTING

University Medical Centre Groningen, the Netherlands.

SUBJECTS

Thiry-eight children aged 1-13 years, who were consecutively referred to the University Medical Centre Groningen for DBPCFC between January 2002 and February 2004.

RESULTS

Among the 38 children undergoing DBPCFCs, there were 15 challenges with egg, 15 with peanut, five with hazelnut and three with soy. Fifteen food challenges (39%) were positive. Small quantities of allergenic foods were inadvertently present in the diets of 13 patients (34%), were possibly present in the diets of 14 patients (37%) and could not be identified in the diets of 11 patients (29%). Seven patients (54%) who had inadvertently ingested small quantities of allergenic foods without sequelae had a positive DBPCFC.

CONCLUSION

Dietary avoidance was incomplete and not feasible in most cases. Tolerance of small amounts of allergenic foods does not preclude positive challenge reactions. Dietary assessment does not seem a useful tool in predicting the outcome of DBPCFC in children adhering to an elimination diet.

SPONSORSHIP

The Stichting Astma Bestrijding (Foundation for the Prevention of Asthma), The Netherlands.