Increasing prevalence of asthma, respiratory symptoms, and allergic diseases: Four repeated surveys from 1993-2014

Predictive Value of Fractional Exhaled Nitric Oxide (FeNO) in the Diagnosis of Asthma for Epidemiological Purposes-An 8-Year Follow-Up Study

At the population level, respiratory symptoms in children can be estimated cross-sectionally. However, such methods require additional objective support parameters, such as the measurement of fractional exhaled nitric oxide (FeNO). The aim of the present study was to analyze if the FeNO value measured at baseline can have a predictive value for asthma-like symptoms after 8 years of measurement.

METHODS

The follow-up included 128 (out of 447) children, 70 girls and 58 boys. The FeNO was measured at baseline only. The prevalence of asthma-like symptoms was measured with the adopted version of the ISAAC questionnaire.

RESULTS

After 8 years of FeNO measurement, 5 new cases of asthma, 2 cases of attacks of dyspnoea, 1 case of wheezy in the chest, and 18 cases of allergic rhinitis occurred. The FeNO values, measured at the baseline of the study, for new cases of the above diseases were 53.4 ± 75.9 ppb, 11 ± 1.5 ppb, 12.0 ppb, and 16.3 ± 12.4 ppb, respectively. The best diagnostic accuracy parameters were found in the new cases of asthma, where the sensitivity was 40.0%, the specificity was 98.6%, and the AUC was 66.6%. The diagnostic odds ratio was 46.9 when considering the FeNO cut-off >35 ppb.

CONCLUSIONS

The FeNO measurement is a fair method for asthma prognosis in early school-aged children with asthma-like symptoms measured on the population level but requires further confirmation at the clinical level with more accurate diagnostic tools.

Exposure to air pollution concentrations of various intensities in early life and allergic sensitisation later in childhood

BACKGROUND

Evidence on the relationship between air pollution and allergic sensitisation in childhood is inconsistent, and this relationship has not been investigated in the context of smoke events that are predicted to increase with climate change. Thus, we aimed to evaluate associations between exposure in two early life periods to severe levels of particulate matter with an aerodynamic diameter < 2.5 μm (PM2.5) from a mine fire, background PM2.5, and allergic sensitisation later in childhood.

METHODS

We measured specific immunoglobulin E (IgE) levels for seven common aeroallergens as well as total IgE levels in a cohort of children who had been exposed to the Hazelwood coal mine fire, either in utero or during their first two years of life, in a regional area of Australia where ambient levels of PM2.5 are generally low. We estimated personal exposure to fire-specific emissions of PM2.5 based on a high-resolution meteorological and pollutant dispersion model and detailed reported movements of pregnant mothers and young children during the fire. We also estimated the usual background exposure to PM2.5 at the residential address at birth using a national satellite-based land-use regression model. Associations between both sources of PM2.5 and sensitisation to dust, cat, fungi, and grass seven years after the fire were estimated with logistic regression, while associations with total IgE levels were estimated with linear regression.

RESULTS

No association was found between the levels of exposure at either developmental stage to fire-related PM2.5 and allergic sensitisation seven years after the event. However, levels of background exposure were positively associated with sensitisation to dust (OR = 1.90, 95%CI = 1.12,3.21 per 1 μg/m3).

CONCLUSIONS

Chronic but low exposure to PM2.5 in early life could be more strongly associated with allergic sensitisation in childhood than time-limited high exposure levels, such as the ones experienced during landscape fires.

A nerve-goblet cell association promotes allergic conjunctivitis through rapid antigen passage

The penetration of allergens through the epithelial layer is the initial step in the development of allergic conjunctivitis. Although pollinosis patients manifest symptoms within minutes after pollen exposure, the mechanisms of the rapid transport of the allergens remain unclear. In the present study, we found that the instillation of pollen shells rapidly induces a large number of goblet cell-associated antigen passages (GAPs) in the conjunctiva. Antigen acquisition by stromal cells, including macrophages and CD11b+ dendritic cells, correlated with surface GAP formation. Furthermore, a substantial amount of antigen was transported to the stroma during the first 10 minutes of pollen exposure, which was sufficient for the full induction of an allergic conjunctivitis mouse model. This inducible, rapid GAP formation and antigen acquisition were suppressed by topical lidocaine or trigeminal nerve ablation, indicating that the sensory nervous system plays an essential role. Interestingly, pollen shell-stimulated GAP formation was not suppressed by topical atropine, suggesting that the conjunctival GAPs and intestinal GAPs are differentially regulated. These results identify pollen shell-induced GAP as a therapeutic target for allergic conjunctivitis.

Acid-suppressive medication and incidence of chronic childhood immune-mediated diseases: A scoping review

BACKGROUND

Use of acid-suppressive medications (ASMs), for example, proton pump inhibitors (PPIs) and histamine-2 receptor antagonists (H2RAs), has been rising along with the incidence of pediatric immune-mediated diseases (IMDs). We conducted a scoping review to characterize the literature about prenatal or pediatric exposure to ASMs in relation to incident pediatric IMDs.

METHODS

Electronic searches were conducted to identify studies from 2001 to 2023 on (a) prenatal or pediatric exposure to PPIs and/or H2RAs and (b) the risk of developing chronic IMDs during childhood. Eligible studies after title/abstract and full-text screening underwent data abstraction.

RESULTS

Of 26 eligible studies, 11 focused on prenatal ASM exposure and 16 on pediatric exposure. Asthma was the most commonly investigated outcome (16 studies), followed by other allergic diseases (8), eosinophilic esophagitis (3), inflammatory bowel disease (2), and other autoimmune diseases (2). Positive associations between ASM exposure and pediatric IMD outcomes emerged in all but two recent studies, which reported null or negative associations with allergic diseases. The strength of associations was similar across exposure times (prenatal/pediatric), medications (PPIs/H2RAs), and outcomes. Dose-response relationships were often present (7/11 studies). Reported effects by trimester and age of exposure varied. Commonly reported limitations were residual confounding, exposure misclassification, and outcome misclassification.

CONCLUSION

In summary, prenatal or pediatric exposure to PPIs and/or H2RAs has frequently, but not exclusively, been associated with the development of asthma, other allergic diseases, and chronic gastrointestinal IMDs. However, concerns remain about confounding and other sources of bias. Prescribers and families should be aware of these possible risks of ASMs.

Sanya climatic-treatment cohort profile: objectives, design, and baseline characteristics

Background

The prevalence of allergic diseases has increased globally, climate and environment also have important effects on respiratory or allergic diseases. However, population-based studies investigating the impact of tropical climates and environments on migratory-bird old people (MBOP) are lacking.

Methods/Design

For this prospective cohort study, we recruited 756 participants from the community in Sanya City, Hainan Province, China. In addition to the completed baseline survey, a follow-up survey will be conducted during the periods of October-December and March-April for the next 3 years of MBEPs from northern China who spend the winter in Sanya. We will continue to record the height, weight, and blood pressure of all participants, as well as lung function for those with asthma and chronic obstructive pulmonary disease (COPD). Venous blood at baseline and urine samples will be collected during follow-up.

Results

A total of 756 volunteers were recruited. Their average age is 66.1 years; 32.1% of them have high-school educations, while 37.3% have graduated from college or done undergraduate studies. The top five diseases in this cohort are allergic rhinitis (57.9%); eczema, urticaria, or dermatitis (35.6%); bronchitis and bronchiectasis (35.6%); asthma (14.7%); and emphysema (11.7%). Compared with their symptoms while at their summer places of residence, rates of remission reported by participants while living in Sanya were 80.4% for allergic rhinitis, 82.3% for bronchitis and emphysema, 85.2% for asthma, 96.0% for COPD (P < 0.001).

Conclusions

The baseline survey has been completed. The preliminary findings support that a tropical climate may relieve the symptoms of allergic diseases in migratory-bird old people.

Prevalence and time trends of symptoms of allergic rhinitis and rhinoconjunctivitis in Spanish children: Global Asthma Network (GAN) study

INTRODUCTION

The time trends of the prevalence of rhinitis, rhinoconjunctivitis and nasal allergy previously described in the ISAAC (International Study of Asthma and Allergies in Childhood) in 2002 are unknown; or if the geographical or age differences in Spain persist.

OBJECTIVE

To describe the prevalence of rhinitis, rhinoconjunctivitis and nasal allergy in different Spanish geographical areas and compare them with those of the ISAAC.

METHODS

Cross-sectional study of the prevalence of rhinitis, rhinoconjunctivitis and nasal allergy, carried out in 2016-2019 on 19943 adolescents aged 13-14 years and 17215 schoolchildren aged 6-7 years from six Spanish areas (Cartagena, Bilbao, Cantabria, La Coruña, Pamplona, and Salamanca), through a questionnaire based on the Global Asthma Network (GAN) protocol.

RESULTS

The prevalences of recent rhinitis and rhinoconjunctivitis (last 12 months), and nasal allergy/hay fever were 35.1%, 17.6%, and 14.6% in the adolescents and 20%, 8.5%, and 8.9% in the schoolchildren, respectively, with rhinoconjunctivitis in adolescents varying from 20.9% in Bilbao to 13.4% in Cartagena; and in schoolchildren, from 9.8% in La Coruña to 6.4% in Pamplona. These prevalences of rhinoconjunctivitis and nasal allergy in adolescents were higher than those described in the ISAAC (16.3% and 13%) and similar in schoolchildren to the ISAAC (9% and 9.4%).

CONCLUSIONS

There has been a stabilisation of rhinitis, rhinoconjunctivitis and nasal allergy in schoolchildren that slows the previous upward trend of ISAAC; and a slight non-significant increase in rhinoconjunctivitis and nasal allergy in adolescents. The variability found in adolescents would require local research to be better understood.

Birch pollen-The unpleasant herald of spring

Type I respiratory allergies to birch pollen and pollen from related trees of the order Fagales are increasing in industrialized countries, especially in the temperate zone of the Northern hemisphere, but the reasons for this increase are still debated and seem to be multifaceted. While the most important allergenic molecules of birch pollen have been identified and characterized, the contribution of other pollen components, such as lipids, non-allergenic immunomodulatory proteins, or the pollen microbiome, to the development of allergic reactions are sparsely known. Furthermore, what also needs to be considered is that pollen is exposed to external influences which can alter its allergenicity. These external influences include environmental factors such as gaseous pollutants like ozone or nitrogen oxides or particulate air pollutants, but also meteorological events like changes in temperature, humidity, or precipitation. In this review, we look at the birch pollen from different angles and summarize current knowledge on internal and external influences that have an impact on the allergenicity of birch pollen and its interactions with the epithelial barrier. We focus on epithelial cells since these cells are the first line of defense in respiratory disease and are increasingly considered to be a regulatory tissue for the protection against the development of respiratory allergies.

Identification of redundancy between human FcεRIβ and MS4A6A proteins points toward additional complex mechanisms for FcεRI trafficking and signaling

BACKGROUND

Allergic diseases are triggered by signaling through the high-affinity IgE receptor, FcεRI. In both mast cells (MCs) and basophils, FcεRI is a tetrameric receptor complex comprising a ligand-binding α subunit (FcεRIα), a tetraspan β subunit (FcεRIβ, MS4A2) responsible for trafficking and signal amplification, and a signal transducing dimer of single transmembrane γ subunits (FcεRIγ). However, FcεRI also exists as presumed trimeric complexes that lack FcεRIβ and are expressed on several cell types outside the MC and basophil lineages. Despite known differences between humans and mice in the presence of the trimeric FcεRI complex, questions remain as to how it traffics and whether it signals in the absence of FcεRIβ. We have previously reported that targeting FcεRIβ with exon-skipping oligonucleotides eliminates IgE-mediated degranulation in mouse MCs, but equivalent targeting in human MCs was not effective at reducing degranulation.

RESULTS

Here, we report that the FcεRIβ-like protein MS4A6A exists in human MCs and compensates for FcεRIβ in FcεRI trafficking and signaling. Human MS4A6A promotes surface expression of FcεRI complexes and facilitates degranulation. MS4A6A and FcεRIβ are encoded by highly related genes within the MS4A gene family that cluster within the human gene loci 11q12-q13, a region linked to allergy and asthma susceptibility.

CONCLUSIONS

Our data suggest the presence of either FcεRIβ or MS4A6A is sufficient for degranulation, indicating that MS4A6A could be an elusive FcεRIβ-like protein in human MCs that performs compensatory functions in allergic disease.

The protective role of conjunctival goblet cell mucin sialylation

Gel-forming mucins secreted by conjunctival goblet cells have been implicated in the clearance of allergens, pathogens, and debris. However, their roles remain incompletely understood. Here we show that human and mouse conjunctival goblet cell mucins have Alcian blue-detectable sialic acids, but not sulfates in the steady state. Interestingly, Balb/c mouse strain lacks this sialylation due to a point mutation in a sialyltransferase gene, St6galnac1, which is responsible for sialyl-Tn synthesis. Introduction of intact St6galnac1 to Balb/c restores the sialylation of conjunctival goblet cell mucus. Sialylated mucus efficiently captures and encapsulates the allergen particles in an impenetrable layer, leading to the protection of mice from the development of allergic conjunctivitis. Expression of ST6GALNAC1 and sialyl-Tn is upregulated in humans under conditions with chronic stimuli. These results indicate that the sialylated glycans on the ocular mucins play an essential role in maintaining the conjunctival mucosa by protecting from the incoming foreign bodies such as allergen particles.

Childhood Wheeze, Allergic Rhinitis, and Eczema in Hong Kong ISAAC Study from 1995 to 2015

BACKGROUND

The prevalence of allergic diseases has been increasing in developing areas but has reached a plateau in many developed areas. Regular surveys are imperative to assess the disease burden for the prioritization of resource allocation.

OBJECTIVES

We examined the change in the prevalence of wheezing, allergic rhinitis (AR), and eczema in school-aged children with possible associative factors and possible health effects of school air quality.

METHODS

This was the third repeated cross-sectional study conducted in 2015-2016 using the International Study of Asthma and Allergies in Childhood (ISAAC) protocol. Our first and second surveys were conducted in 1994-1995 and 2000-2001, respectively. Regarding the third survey, we recruited 3698 children aged 6-7 from 33 local schools in 18 districts. Air quality, temperature, and humidity were also measured. The changes in prevalence, multiple regression, and GLIMMIX procedure were analyzed.

RESULTS

From our first survey to our third survey, the increased prevalences for lifetime wheeze, current wheeze, lifetime rhinitis, current rhinitis, current rhinoconjunctivitis, lifetime chronic rash, and current chronic rash were 4.2%, 2.1%, 12.5%, 12.6%, 14.2%, 3.9%, and 4.1%, respectively. Increased prevalence of parental atopy had the strongest association with an increased prevalence of each of these seven health outcomes. There was no significant association between school air pollutant levels and the prevalence of health outcomes.

CONCLUSIONS

There was an increase in the prevalence of wheezing, allergic rhinitis, and eczema across the surveys. The most important associated risk factor identified was the increased prevalence of a parental history of atopy.

Prevalence, causes and treatments of allergic rhinitis in Malaysia: a literature review

Recently, allergic rhinitis (AR) cases have been surging rapidly in many developing countries. However, the prevalence, risk factors and treatment modalities for AR within the Malaysian population have not been thoroughly evaluated. The present study aimed to provide a complete review of literature on allergic rhinitis in Malaysia. Available data indicated that the prevalence of AR varied across different age groups and regions in Malaysia, but there is an increasing trend among the younger population. The key contributing factor is exposure and sensitization towards several airborne allergens, mainly house dust mites, cat fur and fungi, with possible genetic predispositions. In addition, variations in the symptom severity may be associated with racial orientations. For management of the disease, standard prescriptions of conventional drugs (antihistamines, intranasal corticosteroids and nasal decongestants) remain as the treatment of choice. A small proportion of the native residents tend to resort to alternative approaches of self-healing through aromatherapy and natural food consumption such as tiger’s milk mushroom and Tualang honey. In conclusion, the increase in the cases of AR in Malaysia is due to environmental and genetic factors which requires proper medical intervention as treatment strategies. The utilization of holistic approaches requires further studies and clear understanding prior to their integration into the standard of care. There are still many gaps in the knowledge and management of allergic rhinitis which demands further attention from the research community.

The Accuracy of a Screening Tool in Epidemiological Studies-An Example of Exhaled Nitric Oxide in Paediatric Asthma

Diagnostic tests are widely used in medicine, especially in the clinical setting. The doctor's decision regarding the treatment process is mostly based on the result of the diagnostic test. The value of the test is expressed by its accuracy. It is easier to verify the accuracy of a diagnostic test in a clinical setting in comparison to an epidemiological setting. Moreover, a very good test may not work in epidemiological settings in the same effective way as in a clinical setting, especially because the accuracy is affected by the prevalence of the disease. The aim of the study is to assess the accuracy of FeNO measurement in different respiratory disorders or symptoms, including their prevalence, in a childhood population. The secondary aim is to suggest the optimal FeNO cut-off for epidemiological screening for respiratory diseases and symptoms.

METHODS

The cross-sectional study included 447 children (50.8% boys and 49.2% girls) aged 6-9 years. An adapted version of the ISAAC questionnaire was used for the assessment of the respiratory status. FeNO was measured with an electrochemical device (Niox Mino) according to ERS/ATS recommendations. For interpretation, the FeNO cut-off values of 20 parts per billion (ppb), 25 ppb and 35 ppb were applied taking the real-life prevalence of the disease or symptoms into consideration and also for simulated prevalences of 20%, 30%, 40%, 50% for the interpretation of the accuracy of the test. The accuracy was calculated according to the following formula: Accuracy = (Prevalence) (Sensitivity) + (1- Prevalence) (Specificity). The area under the curve was calculated based on logistic regression.

RESULTS

For all respiratory outcomes, FeNO accuracy decreased with increasing prevalence, and in general the area under the curve (AUC) was low. The highest FeNO accuracy was found for any asthma diagnosis (with possible coexisting diseases/symptoms), i.e., 78.6%, 92.8% and 88.5% for FeNO cut-offs >19 ppb, >24 ppb and >34 ppb, respectively. The AUC was 0.628. For the same FeNO cut-offs, the accuracy of an asthma diagnosis without any coexisting diseases and symptoms was 81.2%, 87.5%, 92.9%, respectively, with an AUC of 0.757.

CONCLUSION

FeNO accuracy decreases with increasing prevalence of the respiratory disease and symptoms. The best accuracy for the FeNO cut-off in the screening of asthma for epidemiological purposes is 35 ppb. For isolated asthma, the best accuracy for FeNO was 92.9%.

Effect of Dupilumab on Blood Eosinophil Counts in Patients With Asthma, Chronic Rhinosinusitis With Nasal Polyps, Atopic Dermatitis, or Eosinophilic Esophagitis

BACKGROUND

Transient increases in blood eosinophil counts have been observed in dupilumab clinical trials.

OBJECTIVE

To assess eosinophil counts and eosinophilia-related treatment-emergent adverse events (TEAEs) across 11 dupilumab clinical trials, comparing adult and adolescent patients with asthma and adult patients with chronic rhinosinusitis with nasal polyps (CRSwNP), atopic dermatitis, and eosinophilic esophagitis.

METHODS

Eosinophil counts, rates of eosinophilia-related TEAEs or treatment-emergent eosinophilia (>1,500 cells/μL), discontinuations, clinical symptoms, and efficacy in patients with asthma or CRSwNP with treatment-emergent eosinophilia are presented.

RESULTS

Transient increases in mean eosinophil counts were observed in dupilumab-treated patients with asthma (mean range across studies at baseline: 349-370 cells/μL; week 4: 515-578 cells/μL), CRSwNP (baseline: 440-448 cells/μL; week 16: 595 cells/μL), and atopic dermatitis (baseline: 434-600 cells/μL; week 4: 410-710 cells/μL), followed by a decline starting by week 24 to baseline or lower. No increases were seen in patients with eosinophilic esophagitis (baseline: 310 cells/μL; week 4: 230 cells/μL). In dupilumab-treated patients across all studies, rates of eosinophilia TEAEs were 0% to 13.6%. Clinical symptoms associated with increased eosinophils were rare (seven of 4,666 dupilumab-treated patients, including six cases of eosinophilic granulomatosis with polyangiitis) and occurred only in patients with asthma or CRSwNP. Eosinophilia was not associated with reduced dupilumab efficacy.

CONCLUSIONS

Transient increases in eosinophil counts with dupilumab treatment did not affect efficacy and were rarely of clinical consequence. It remains important for physicians to base judgment on individual patient history and baseline eosinophil counts and to be alert to hypereosinophilic symptoms.

Association of childhood rhinitis with phthalate acid esters in household dust in Shanghai residences

OBJECTIVE

Phthalate acid esters (PAEs) have been identified to be associated with children's health. Present study was conducted to assess associations between PAEs in household dust and childhood rhinitis.

METHODS

Based on phase II of CCHH study (China, Children, Home, Health) conducted in Shanghai, China, 266 indoor dust samples were collected from participants' families. Concentrations of PAEs in dust samples were measured by chemical treatment and gas chromatograph-mass spectrometer. Information about individuals and residences was surveyed by questionnaires. Logistic regression models were applied to obtain the associations between PAEs and childhood rhinitis.

RESULTS

Higher concentrations of benzyl butyl phthalate (BBP) were found in those families with children who had diagnosed rhinitis. Significantly higher concentrations of bis(2-ethylhexyl) phthalate (DEHP) and PAEs with high molecular weight (HMW-PAEs) were found in the positive group of lifetime rhinitis. Using the multiple and ordinal logistic regression models adjusted by covariates, dibutyl phthalate (DBP), DEHP, and HMW-PAEs were found to be significantly associated with diagnosed rhinitis. Boys who exposure to higher concentrations of DBP, DEHP, HMW-PAEs, and total PAEs have significant associations with diagnosed rhinitis compared with girls who exposure to lower concentration of PAEs.

CONCLUSIONS

Present observational study indicated that exposure to high concentrations of DBP, DEHP, and HMW-PAEs in house settled dust was a risk factor for rhinitis for children, especially for boys.

Worldwide time trends in prevalence of symptoms of rhinoconjunctivitis in children: Global Asthma Network Phase I

BACKGROUND

The Global Asthma Network (GAN), by using the International Study of Asthma and Allergies in Childhood (ISAAC) methodology, has updated trends in prevalence of symptoms of childhood allergic diseases, including non-infective rhinitis and conjunctivitis ('rhinoconjunctivitis'), which is reported here.

METHODS

Prevalence and severity of rhinoconjunctivitis were assessed by questionnaire among schoolchildren in GAN Phase I and ISAAC Phase I and III surveys 15-23 years apart. Absolute rates of change in prevalence were estimated for each centre and modelled by multi-level linear regression to compare trends by age group, time period and per capita national income.

RESULTS

Twenty-seven GAN centres in 14 countries surveyed 74,361 13- to 14-year-olds ('adolescents') and 45,434 6- to 7-year-olds ('children'), with average response proportions of 90% and 79%, respectively. Many centres showed highly significant (p < .001) changes in prevalence of rhinoconjunctivitis in the past year ('current rhinoconjunctivitis') compared with ISAAC. The direction and magnitude of centre-level trends varied significantly (p < .001) both within and between countries. Overall, current rhinoconjunctivitis prevalence decreased slightly from ISAAC Phase III to GAN: -1.32% per 10 years, 95% CI [-2.93%, +0.30%] among adolescents; and -0.44% [-1.29%, +0.42%] among children. Together, these differed significantly (p < .001) from the upward trend within ISAAC. Among adolescents, centre-level trends in current rhinoconjunctivitis were highly correlated with those for eczema symptoms (rho = 0.72, p < .0001) but not with centre-level trends in asthma symptoms (rho = 0.15, p = .48). Among children, these correlations were positive but not significant.

CONCLUSION

Symptoms of non-infective rhinoconjunctivitis among schoolchildren may no longer be on the increase globally, although trends vary substantially within and between countries.

Resolvin D2 and Resolvin D1 Differentially Activate Protein Kinases to Counter-Regulate Histamine-Induced [Ca2+]i Increase and Mucin Secretion in Conjunctival Goblet Cells

Resolvin (Rv) D2 and RvD1 are biosynthesized from docosahexaenoic acid (DHA) and promote resolution of inflammation in multiple organs and tissues, including the conjunctiva. Histamine is a mediator produced by mast cells in the conjunctiva during the allergic response. We determined the interaction of RvD2 with histamine and its receptor subtypes in cultured conjunctival goblet cells and compared them with RvD1 by measuring intracellular [Ca²⁺] and mucous secretion. Treatment with RvD2 significantly blocked the histamine-induced [Ca²⁺]_i increase as well as secretion. RvD2 and RvD1 counter-regulate different histamine receptor subtypes. RvD2 inhibited the increase in [Ca²⁺]_i induced by the activation of H1, H3, or H4 receptors, whereas RvD1 inhibited H1 and H3 receptors. RvD2 and RvD1 also activate distinct receptor-specific protein kinases to counter-regulate the histamine receptors, probably by phosphorylation. Thus, our data suggest that the counter-regulation of H receptor subtypes by RvD2 and RvD1 to inhibit mucin secretion are separately regulated.

The nanotopography of SiO2 particles impacts the selectivity and 3D fold of bound allergens

A detailed description of the changes that occur during the formation of protein corona represents a fundamental question in nanoscience, given that it not only impacts the behaviour of nanoparticles but also affects the bound proteins. Relevant questions include whether proteins selectively bind particles, whether a specific orientation is preferred for binding, and whether particle binding leads to a modulation of their 3D fold. For allergens, it is important to answer these questions given that all these effects can modify the allergenic response of atopic individuals. These potential impacts on the bound allergen are closely related to the specific properties of the involved nanoparticles. One important property influencing the formation of protein corona is the nanotopography of the particles. Herein, we studied the effect of nanoparticle porosity on allergen binding using mesoporous and non-porous SiO₂ NPs. We investigated (i) the selectivity of allergen binding from a mixture such as crude pollen extract, (ii) whether allergen binding results in a preferred orientation, (iii) the influence of binding on the conformation of the allergen, and (iv) how the binding affects the allergenic response. Nanotopography was found to play a major role in the formation of protein corona, impacting the physicochemical and biological properties of the NP-bound allergen. The porosity of the surface of the SiO₂ nanoparticles resulted in a higher binding capacity with pronounced selectivity for (preferentially) binding the major birch pollen allergen Bet v 1. Furthermore, the binding of Bet v 1 to the mesoporous rather than the non-porous SiO₂ nanoparticles influenced the 3D fold of the protein, resulting in at least partial unfolding. Consequently, this conformational change influenced the allergenic response, as observed by mediator release assays employing the sera of patients and immune effector cells. For an in-depth understanding of the bio-nano interactions, the properties of the particles need to be considered not only regarding the identity and morphology of the material, but also their nanotopography, given that porosity may greatly influence the structure, and hence the biological behaviour of the bound proteins. Thus, thorough structural investigations upon the formation of protein corona are important when considering immunological outcomes, as particle binding can influence the allergenic response elicited by the bound allergen.

Pediatric asthma incidence rates in the United States from 1980 to 2017

BACKGROUND

Few studies have examined longitudinal asthma incidence rates (IRs) from a public health surveillance perspective.

OBJECTIVE

Our aim was to calculate descriptive asthma IRs in children over time with consideration for demographics and parental asthma history.

METHODS

Data from 9 US birth cohorts were pooled into 1 population covering the period from 1980 to 2017. The outcome was earliest parental report of a doctor diagnosis of asthma. IRs per 1,000 person-years were calculated.

RESULTS

The racial/ethnic backgrounds of the 6,283 children studied were as follows: 55% European American (EA), 25.5% African American (AA), 9.5% Mexican-Hispanic American (MA) and 8.5% Caribbean-Hispanic American (CA). The average follow-up was 10.4 years (SD = 8.5 years; median = 8.4 years), totaling 65,291 person-years, with 1789 asthma diagnoses yielding a crude IR of 27.5 per 1,000 person-years (95% CI = 26.3-28.8). Age-specific rates were highest among children aged 0 to 4 years, notably from 1995 to 1999, with a decline in EA and MA children in 2000 to 2004 followed by a decline in AA and CA children in 2010 to 2014. Parental asthma history was associated with statistically significantly increased rates. IRs were similar and higher in AA and CA children versus lower but similar in EA and MA children. The differential rates by sex from birth through adolescence principally resulted from a decline in rates among males but relatively stable rates among females.

CONCLUSIONS

US childhood asthma IRs varied dramatically by age, sex, parental asthma history, race/ethnicity, and calendar year. Higher rates in the 0- to 4-year-olds group, particularly among AA/CA males with a parental history of asthma, as well as changes in rates over time and by demographic factors, suggest that asthma is driven by complex interactions between genetic susceptibility and variation in time-dependent environmental and social factors.

Pollen shells and soluble factors play non-redundant roles in the development of allergic conjunctivitis in mice

PURPOSE

We aimed to clarify the role of particulate allergen exposure to the conjunctiva in the development of allergic conjunctivitis.

METHODS

We administered ragweed pollen suspension, pollen extract, pollen shell, particulate air pollutants, and their combinations to the mouse conjunctiva five days a week without prior sensitization. Clinical signs were scored. Histological changes, cellular infiltrations, mRNA expressions, lymph node cell recall responses, and serum immunoglobulin levels were assessed. Immune cell-depleting antibodies and ST2 knockout mice were used to investigate the cellular and molecular requirements.

RESULTS

Pollen suspension, but not the extract or shell alone, induced robust eosinophilic conjunctivitis, accompanied by a proliferative response of epithelial cells. A combination of pollen extract and shell completely restored eosinophil accumulation. In addition, eosinophilic conjunctivitis was induced by a mixture of particulate air pollutants and pollen extract. Mechanistically, eosinophil accumulation was ameliorated by deficiency of the IL-33 receptor ST2 and abolished by depleting CD4⁺ T cells. Pollen shells, but not the extract, induced IL-33 release from conjunctival epithelial cells in vivo.

CONCLUSIONS

Our results indicate the non-redundant roles for the allergens' particulate properties and soluble factors in the development of allergic conjunctivitis.

Molecular mechanisms and treatment modalities in equine Culicoides hypersensitivity

Equine Culicoides hypersensitivity (CH) is the most common allergic condition in horses affecting the skin. This review focuses on immunopathology and molecular mechanisms of equine CH. The role of eosinophils is emphasized, as well as disease severity and the influence of long-term chronic allergen exposure on T helper (Th) 2 cells. Using current knowledge from human allergic disorders, similar effects are hypothesized in equine patients. Key aspects of CH diagnosis and treatment are discussed, focusing on allergen specific immunotherapy and allergen-independent approaches, such as targeting hypereosinophilia through interleukin-5 and allergic non-histaminic pruritus though interleukin-31.

House dust mite (HDM) and storage mite (SM) molecular sensitisation profiles and association with clinical outcomes in allergic asthma and rhinitis: protocol for a systematic review

INTRODUCTION

Identification and characterisation of single allergens at molecular level is important. Component-resolved diagnosis offers the possibility of higher diagnostic precision, thereby allowing better patient management. House dust mites (HDM) have a worldwide distribution. Studies from different countries have shown that IgE-mediated allergy to storage mites (SM) is important in rural and urban populations. With the availability of HDM and SM molecular allergen components, studies have investigated whether different molecular sensitisation profiles are associated with clinical disease outcomes. However, no previous systematic review has synthesised the underlying evidence.

METHODS AND ANALYSIS

We will search Cochrane Library (Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials (CENTRAL), Cochrane Methodology Register), MEDLINE, EMBASE, CINAHL, AMED, ISI Web of Science (Science and Social Science Index) from inception to March 2020. Unpublished and ongoing work, as well as research in progress will be searched in www.ClinicalTrials.gov; www.controlledtrials.com and wwwanzctrorgau. We will contact an international panel of experts in this field. No language restrictions will apply; translations will be undertaken where necessary. The Critical Appraisal Skills Programme quality assessment tool will be used to appraise the methodological quality of included studies. A descriptive summary with data tables will be constructed, and if adequate, meta-analysis using random effects will be performed. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses checklist will be followed for reporting.

ETHICS AND DISSEMINATION

Since this systematic review will be only based on published and retrievable literature, no ethics approval is required. We will publish the systematic review in an international peer-reviewed journal.

TRIAL REGISTRATION NUMBER

reviewregistry959.

Allergen immunotherapy for house dust mite-induced rhinitis: prescriptive criteria

Allergic rhinitis (AR) is a very common disease. In most cases, therapy is based on symptomatic drugs, while allergen immunotherapy (AIT), which is the only one to act on the cause of the disease, is reserved for patients with a greater burden of disease. In particular, the possible evolution towards asthma substantiates the use of AIT, but requires the availability of diagnostic indices related to the risk of developing asthma. We analyzed the available literature on risk factors for onset of asthma in patients with AR, including bronchial hyperresponsiveness, uncovering by respiratory function tests of airway impairment, measurement of fractioned exhaled nitric oxide, given IgE sensitization pattern, and respiratory infections detected by nasal mucus samples or by particular microbiomes. Most of these risk predictors have been investigated too little or do not have consistent results, while various studies have confirmed that early bronchial impairment in AR patients, particularly concerning small airways, should be considered as prescriptive criteria for AIT. (www.actabiomedica.it)

Coexistence of asthmatic and non-respiratory allergic symptoms in children of Batumi Region, Georgia: occurrence and association with known diagnosis of asthma

OBJECTIVES

Our recent studies showed that in children in the Batumi region, Georgia, underdiagnosis of asthma is 65%, and that not all children with known asthma had a history of allergic disorders. So, we decided to assess the association of known diagnosis of paediatric asthma with asthma-like symptoms and non-respiratory allergic symptoms and diseases using questionnaire-derived data provided by respiratory health survey.

METHODS

Subjects of the cross-sectional population-based study were 3,239 urban and 2,113 rural children aged 5-17 years whose respiratory status was assessed using the International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire. For children with a known diagnosis of asthma, the occurrence of respiratory symptoms suggestive of asthmatic tendency and of allergic symptoms and diseases was measured and statistical association of known asthma with the respiratory and allergic symptoms was expressed as odds ratios (OR) and their 95% confidence intervals (95% CI).

RESULTS

Respiratory and all allergic symptoms and diseases, except for eczema, were statistically significantly (p < 0.05) more prevalent in children with asthma than in children without asthma. Based on the distribution of asthma vis-à-vis asthmatic tendency without or with allergic symptoms and allergic diseases the following odds ratios expressing likelihood of asthma were obtained: for asthmatic tendency: OR = 18.09 (95% CI: 11.82-27.68), for any allergic symptom: OR = 6.85 (95% CI: 4.69-10.02), for any allergic disease: OR = 10.75 (95% CI: 7.36-15.70), for asthmatic tendency with coexisting any allergic symptom: OR = 18.94 (95% CI: 12.96-27.68), for asthmatic tendency with coexisting any allergic disease: OR = 25.65 (95% CI: 17.47-37.67), and for asthmatic tendency with coexisting any allergic symptom and allergic disease: OR = 27.02 (95% CI: 18.18-40.15).

CONCLUSIONS

The findings support the view that in epidemiological setting questionnaire-based studies on asthma seems to more readily identify cases in children with more severe clinical presentation of the disease and with coexisting allergic disorders, perhaps reflecting diagnostic practices of consulting paediatricians.

The treatment of asthma using the Chinese Materia Medica

ETHNOPHARMACOLOGICAL RELEVANCE

Asthma is a costly global health problem that negatively influences the quality of life of patients. The Chinese Materia Medica (CMM) contains remedies that have been used for the treatment of asthma for millennia. This article strives to systematically summarize the current research progress so that more comprehensive examinations of various databases related to CMM anti-asthma drugs, can be performed, so as to sequentially provide effective basic data for development and application of anti-asthma drugs based on the CMM.

MATERIALS AND METHODS

The research data published over the past 20 years for asthma treatment based on traditional CMM remedies were retrieved and collected from libraries and online databases (PubMed, ScienceDirect, Elsevier, Spring Link, Web of Science, PubChem Compound, Wan Fang, CNKI, Baidu, and Google Scholar). Information was also added from classic CMM, literature, conference papers on classic herbal formulae, and dissertations (PhD or Masters) based on traditional Chinese medicine.

RESULTS

This review systematically summarizes the experimental studies on the treatment of asthma with CMM, covering the effective chemical components, typical asthma models, important mechanisms and traditional anti-asthma CMM formulae. The therapy value of the CMM for anti-asthma is clarified, and the original data and theoretical research foundation are provided for the development of new anti-asthmatic data and research for the CMM.

CONCLUSIONS

Substantial progress against asthma has been made through relevant experimental research based on the CMM. These advances improved the theoretical basis of anti-asthma drugs for CMM and provided a theoretical basis for the application of a asthma treatment that is unique. By compiling these data, it is expected that the CMM will now contain a clearer mechanism of action and a greater amount of practical data that can be used for future anti-asthma drug research.

Sex-Steroid Signaling in Lung Diseases and Inflammation

Sex/gender difference exists in the physiology of multiple organs. Recent epidemiological reports suggest the influence of sex-steroids in modulating a wide variety of disease conditions. Sex-based discrepancies have been reported in pulmonary physiology and various chronic inflammatory responses associated with lung diseases like asthma, chronic obstructive pulmonary disease (COPD), pulmonary fibrosis, and rare lung diseases. Notably, emerging clinical evidence suggests that several respiratory diseases affect women to a greater degree, with increased severity and prevalence than men. Although sex-specific differences in various lung diseases are evident, such differences are inherent to sex-steroids, which are major biological variables in men and women who play a central role to control these differences. The focus of this chapter is to comprehend the sex-steroid biology in inflammatory lung diseases and to understand the mechanistic role of sex-steroids signaling in regulating these diseases. Exploring the roles of sex-steroid signaling in the regulation of lung diseases and inflammation is crucial for the development of novel and effective therapy. Overall, we will illustrate the importance of differential sex-steroid signaling in lung diseases and their possible clinical implications for the development of complementary and alternative medicine to treat lung diseases.

Comparison of fractional exhaled nitric oxide in asthmatics with and without allergic rhinitis

PURPOSE OF THE STUDY

The aim of this study was to measure the concentration of FeNO in asthmatics with and without allergic rhinitis (AR) and to determine usefulness of the test in the assessment of asthma control in the Polish population. The next objective of this study was to estimate the cut-off point of FeNO which might be a good indicator of uncontrolled asthma.

MATERIALS AND METHODS

The measurements were taken using the Hyp'Air FeNO in 303 adult patients with asthma, AR, comorbid AR and asthma, and non-diseased volunteers.

RESULTS

FeNO level in healthy adults was similar to the FeNO concentration in AR as well as controlled asthmatic patients without and with AR. Patients with partly controlled and uncontrolled asthma with and without AR had higher FeNO (>60 ppb) levels when compared to adults with controlled disease. The optimal cut-off point of FeNO > 46 ppb and FeNO > 33 ppb was estimated for identification of uncontrolled asthmatics without and with AR, respectively.

CONCLUSION

In conclusion, we found a significant correlation between the FeNO concentration and the level of asthma symptom control in asthmatic patients with and without AR.

Pharmacogenetics of inhaled corticosteroids and exacerbation risk in adults with asthma

BACKGROUND

Inhaled corticosteroids (ICS) are a cornerstone of asthma treatment. However, their efficacy is characterized by wide variability in individual responses.

OBJECTIVE

We investigated the association between genetic variants and risk of exacerbations in adults with asthma and how this association is affected by ICS treatment.

METHODS

We investigated the pharmacogenetic effect of 10 single nucleotide polymorphisms (SNPs) selected from the literature, including SNPs previously associated with response to ICS (assessed by change in lung function or exacerbations) and novel asthma risk alleles involved in inflammatory pathways, within all adults with asthma from the Dutch population-based Rotterdam study with replication in the American GERA cohort. The interaction effects of the SNPs with ICS on the incidence of asthma exacerbations were assessed using hurdle models adjusting for age, sex, BMI, smoking and treatment step according to the GINA guidelines. Haplotype analyses were also conducted for the SNPs located on the same chromosome.

RESULTS

rs242941 (CRHR1) homozygotes for the minor allele (A) showed a significant, replicated increased risk for frequent exacerbations (RR = 6.11, P < 0.005). In contrast, rs1134481 T allele within TBXT (chromosome 6, member of a family associated with embryonic lung development) showed better response with ICS. rs37973 G allele (GLCCI1) showed a significantly poorer response on ICS within the discovery cohort, which was also significant but in the opposite direction in the replication cohort.

CONCLUSION

rs242941 in CRHR1 was associated with poor ICS response. Conversely, TBXT variants were associated with improved ICS response. These associations may reveal specific endotypes, potentially allowing prediction of exacerbation risk and ICS response.

Models for estimating and projecting global, regional and national prevalence and disease burden of asthma: a systematic review

Background

Statistical models are increasingly being used to estimate and project the prevalence and burden of asthma. Given substantial variations in these estimates, there is a need to critically assess the properties of these models and assess their transparency and reproducibility. We aimed to critically appraise the strengths, limitations and reproducibility of existing models for estimating and projecting the global, regional and national prevalence and burden of asthma.

Methods

We undertook a systematic review, which involved searching Medline, Embase, World Health Organization Library and Information Services (WHOLIS) and Web of Science from 1980 to 2017 for modelling studies. Two reviewers independently assessed the eligibility of studies for inclusion and then assessed their strengths, limitations and reproducibility using pre-defined quality criteria. Data were descriptively and narratively synthesised.

Results

We identified 108 eligible studies, which employed a total of 51 models: 42 models were used to derive national level estimates, two models for regional estimates, four models for global and regional estimates and three models for global, regional and national estimates. Ten models were used to estimate the prevalence of asthma, 27 models estimated the burden of asthma – including, health care service utilisation, disability-adjusted life years, mortality and direct and indirect costs of asthma – and 14 models estimated both the prevalence and burden of asthma. Logistic and linear regression models were most widely used for national estimates. Different versions of the DisMod-MR- Bayesian meta-regression models and Cause Of Death Ensemble model (CODEm) were predominantly used for global, regional and national estimates. Most models suffered from a number of methodological limitations – in particular, poor reporting, insufficient quality and lack of reproducibility.

Conclusions

Whilst global, regional and national estimates of asthma prevalence and burden continue to inform health policy and investment decisions on asthma, most models used to derive these estimates lack the required reproducibility. There is a need for better-constructed models for estimating and projecting the prevalence and disease burden of asthma and a related need for better reporting of models, and making data and code available to facilitate replication.

Epidemiological aspects of allergic conjunctivitis

The prevalence of ocular allergies has been increasing worldwide for the past several decades. The geographical distribution and hot spots of rhinoconjunctivitis have been documented in a global survey by the International Study of Asthma and Allergies in Childhood (ISAAC). ISAAC indicated that Africa, Latin America, and Japan were notable for their high prevalence of rhinoconjunctivitis. The outcomes of follow-up studies of regional differences and the characteristics of allergic conjunctivitis are summarized in this review. Currently, comorbid diseases and socioeconomic and environmental factors, including climate and air pollution, are proposed to contribute to the regional differences in the prevalence of allergic conjunctivitis. Of them, rhinitis has been shown repeatedly to be significantly associated with allergic conjunctivitis. Their mechanistic aspects on association with the prevalence of systemic allergic diseases have been reviewed by examining the birth cohort or in vitro analyses. A vision threatening form of ocular allergy, vernal keratoconjunctivitis, is prevalent in the African countries and Japan. Of the proposed associated factors, air pollution was shown to contribute not only to aggravating the symptoms but also to the increase in the incidence of its severe forms. Its mechanistic aspects are discussed in this review in the context of comorbid diseases.

Presentation, diagnosis, and the role of subcutaneous and sublingual immunotherapy in the management of ocular allergy

Allergic eye disease or ocular allergy is a debilitating condition with a significant impact on quality of life and productivity. As atopy continues to be on the rise, primary care providers are likely to encounter increasing numbers of patients with allergic eye disease. This review outlines the classification and pathophysiology of allergic eye disease and its clinical presentation. This paper does not detail traditional first-line therapies of allergic eye disease but describes the interdisciplinary management between the eye-care provider and allergist. It is recommended that patients with ongoing signs and symptoms of ocular allergy despite first-line therapies be referred for allergen immunotherapy, as it is highly effective for treatment of allergic eye disease. Through induction of immune tolerance, allergen immunotherapy is a disease-modifying therapy that can result in long-term improvement of ocular allergy. A thorough literature review was conducted on the efficacy and safety of allergen immunotherapy, including subcutaneous immunotherapy and sublingual immunotherapy, and its role in allergic eye disease.

Divergent trends in the prevalence of asthma-like symptoms and asthma in a developing country: three repeated surveys between 2002 and 2016

INTRODUCTION AND OBJECTIVES

There have been differences in temporal trends of asthma prevalence by geographic region and economic prosperity. The aim of this study was to assess temporal trends in asthma prevalence among young adolescents in Skopje, Republic of North Macedonia as a developing country with a low asthma prevalence.

SUBJECTS AND METHODS

Data were obtained from three cross-sectional surveys (2002, 2006, and 2016) of adolescents (12-15 years) from randomly selected schools in Skopje. Trends in the prevalence of asthma and asthma-like symptoms were investigated descriptively and using multiple logistic regression to adjust for potential confounding factors.

RESULTS

The prevalence of asthma increased, although the changes were not statistically significant (2002: 1.7%; 2006: 2.0%; 2016: 2.8%; p=0.075). Statistically significant (p<0.05) reductions in wheeze prevalence over time (2002, 2006, 2016) were observed for current wheeze (8.8%, 7.2%, 5.5%), exercise-induced wheeze (14.2%, 7.9%, 1.9%), and night dry cough (16.5%, 13.5%, 9.6%). After adjustment for potential confounding factors, there was an increase in asthma likelihood by year compared to 2002 (2006: OR=1.22, 95%CI=0.67-2.22; 2016: OR=2.45, 95%CI=1.24-4.84). In the adjusted analyses, associations between year and the asthma-like symptoms confirmed the descriptive results, except for current wheeze, where statistical significance disappeared.

CONCLUSIONS

Divergent trends in prevalence with a decrease in asthma-like symptoms and an increase in physician-diagnosed asthma in Skopje during a period of 14 years were established. Improved asthma labelling and effective preventative treatment of symptoms may explain some of these changes, although changes in environment and lifestyle could not be ruled out.

Association between maternal age at delivery and allergic rhinitis in schoolchildren: A population-based study

Background

Some studies have shown associations of maternal age at delivery with asthma and food allergy in offspring. However, the relationship between maternal age at delivery and allergic rhinitis is largely unclear. This study aimed to investigate the association between maternal age at delivery and allergic rhinitis in a population sample of Asian children, and to explore potential effect modifiers.

Methods

A total of 1344 singleton-birth children (763 boys, 56.8%; mean age, 6.4 years) participating in the Longitudinal Investigation of Global Health in Taiwanese Schoolchildren (LIGHTS) cohort were evaluated by a modified International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire and interviewed by pediatricians. Allergic sensitization was determined by using Phadiatop Infant. Multiple logistic regression models with covariates adjustment were performed to investigate the association of maternal age at delivery with allergic rhinitis and allergic sensitization in offspring.

Results

Among 1344 study children, 793 (59%) had physician-diagnosed allergic rhinitis. Advanced maternal age at delivery (≥40 years) was significantly associated with increased odds of allergic rhinitis (adjusted odds ratio [AOR] = 4.58, 95% confidence interval [CI]: 1.90–11.03) and allergic sensitization (AOR = 2.86, 95% CI: 1.13–7.22) in offspring. A sex-stratified analysis revealed that the association of advanced maternal age with allergic rhinitis was statistically significant only in female offspring (AOR = 7.02, 95% CI: 1.89–26.14). Stratified analyses by birth order or environmental tobacco smoke exposure during pregnancy did not reveal any significant differences.

Conclusion

Advanced maternal age at delivery was associated with increased risk of allergic rhinitis in Asian children, probably more pronounced among girls.

Outside-in hypothesis revisited: The role of microbial, epithelial, and immune interactions

OBJECTIVE

Our understanding of the origin of allergic diseases has increased in recent years, highlighting the importance of microbial dysbiosis and epithelial barrier dysfunction in affected tissues. Exploring the microbial-epithelial-immune crosstalk underlying the mechanisms of allergic diseases will allow the development of novel prevention and treatment strategies for allergic diseases.

DATA SOURCES

This review summarizes the recent advances in microbial, epithelial, and immune interactions in atopic dermatitis, allergic rhinitis, chronic rhinosinusitis, and asthma.

STUDY SELECTIONS

We performed a literature search, identifying relevant recent primary articles and review articles.

RESULTS

Dynamic crosstalk between the environmental factors and microbial, epithelial, and immune cells in the development of atopic dermatitis, allergic rhinitis, chronic rhinosinusitis, and asthma underlies the pathogenesis of these diseases. There is substantial evidence in the literature suggesting that environmental factors directly affect barrier function of the epithelium. In addition, T-helper 2 (T_H2) cells, type 2 innate lymphoid cells, and their cytokine interleukin 13 (IL-13) damage skin and lung barriers. The effects of environmental factors may at least in part be mediated by epigenetic mechanisms. Histone deacetylase activation by type 2 immune response has a major effect on leaky barriers and blocking of histone deacetylase activity corrects the defective barrier in human air-liquid interface cultures and mouse models of allergic asthma with rhinitis. We also present and discuss a novel device to detect and monitor skin barrier dysfunction, which provides an opportunity to rapidly and robustly assess disease severity.

CONCLUSION

A complex interplay between environmental factors, epithelium, and the immune system is involved in the development of systemic allergic diseases.

A contemporary look at allergic conjunctivitis

Allergic eye disease is common, yet often overlooked in North America. In the U.S., up to 40% of the population is deemed to be affected and this number is growing. Symptoms and signs of ocular allergy can lead to decreased productivity and negatively impact quality of life (QoL). Various treatment options exist to achieve symptom control. For allergic conjunctivitis, ophthalmic agents include antihistamines, mast cell stabilizers, dual-activity agents, nonsteroidal anti-inflammatory drugs (NSAIDs), steroids and some off-label treatments. Immunotherapy is recommended as a therapeutic option. This review provides a summary of the forms of ocular allergies, with a focus on symptoms and signs, impact on QoL, physical examination, diagnosis and therapeutic options of allergic conjunctivitis. Through multidisciplinary collaborations, a simplified algorithm for the treatment of allergic conjunctivitis is proposed for Canadian clinical practice.

Dermatophagoides spp. hypoallergens design: what has been achieved so far?

Introduction: Allergic illnesses are one of the most prevalent immunological disorders worldwide and house dust mites are important triggers of these diseases. Allergen-specific immunotherapy (AIT) is an alternative treatment to pharmacotherapy and among its technologies, recombinant hypoallergenic derivatives have shown promising features, turn them into safer and more efficient allergy vaccines.Areas covered: Patents and scientific publications referring to advances in the design of Dermatophagoides spp. hypoallergenic molecules. Data were obtained from the Espacenet® and PubMed websites, using different key terms, advanced tools and Boolean operators for searches. The retrieved data were then descriptively analyzed, taking into consideration clinical targets, geographical, temporal, collaborative, and different classification aspects of the productions.Expert opinion: Joint advances of molecular biology, genetic engineering, and bioinformatics technologies led to progresses in the design of Dermatophagoides spp. hypoallergenic derivatives. Collaborative networks seem to be an interesting way not only to improve technologies in AIT but also to boost the number of patents, publications, and grants for researchers. The observed trend for the use of hypoallergenic hybrid molecules was a fundamental AIT advance and this type of molecule appears to be a more attractive product for companies and more convenient, efficient, and safer allergy immunotherapy for patients.

Antihistamine effects and safety of fexofenadine: a systematic review and Meta-analysis of randomized controlled trials

Background

As a new generation antihistamine, fexofenadine has been widely used in allergic diseases. However, there is still a lack of collective evidence regarding the antihistamine effects and safety profiles of fexofenadine relative to other antihistamine drugs and placebo. Therefore, we aimed to systematically evaluate the antihistamine effects and safety of fexofenadine.

Methods

An electronic literature search of randomized controlled trials (RCTs) was performed using Embase, Cochrane and PubMed from establishment to January 1st, 2018. RCTs comparing the antihistamine effects or safety (adverse events, sedative effects, and cognitive/psychomotor function) of fexofenadine with either other antihistamines or placebo for healthy subjects and patients with allergy were selected.

Results

Fifty-one studies of 14,551 participants met the inclusion criteria. When compared with the first-generation antihistamines, fexofenadine produced significantly lower adverse events frequency (OR = 0.446; 95% CI: 0.214 to 0.929, P = 0.031), significantly lower sedative effects frequency (OR = 0.265; 95% CI: 0.072 to 0.976, P = 0.046) and significantly less change of all cognitive/psychomotor function. When compared with the second-generation antihistamines, fexofenadine produced significantly marginal sedative effects (OR = 0.59; 95% CI, 0.38 to 0.93; P = 0.02) and significantly less change of most of the cognitive/psychomotor function. When compared with placebo, fexofenadine produced more significant antihistamine effects.

Conclusions

Fexofenadine has a positive antihistamine effect, which is probably no worse than the second-generation antihistamines. Fexofenadine probably has a favorable safety profile, which is more likely better than that of the first-generation antihistamines. There is lack of data to support that fexofenadine has a better overall safety profile compared to the second-generation antihistamines, however, some presently available evidence on sedative effects and certain aspects of cognitive/psychomotor function favors fexofenadine. Therefore, fexofenadine may be worthy of recommendation for safety related workers.

Changes in the prevalence of asthma and related risk factors in adolescents: Three surveys between 1994 and 2015

METHODS

This study assesses the temporal trend of current asthma symptoms prevalence and associated factors in Chilean adolescents from South-Santiago, considering surveys performed in 1994, 2002 and 2015.

RESULTS

The prevalence of current asthma symptoms showed a trend to increase from 11.1% in 1994 to 13.4% in 2015 (p<0.001); physician-diagnosed asthma increased from 11.5% to 13.8%, (p<0.001) whereas severe asthma and asthma with exercise decreased (p<0.001). Female adolescents had a higher prevalence of current asthma in the three surveys (p<0.001), and was a risk factor for asthma in the three surveys. In 2002, frequent consumption of meat and potatoes were associated with current asthma while frequent vigorous exercise was protective. Frequent exercise and parental tobacco smoking were risk for asthma in 2015 (p<0.001). Current active tobacco smoking showed a trend to increase reaching a prevalence of 28.9% in 2015 (p<0.001). There was a consistently low proportion of adolescents with current wheezing and asthma diagnosis (32.1% in 2015) and 37.6% of them had no asthma treatment.

CONCLUSION

The prevalence of current asthma in adolescents from the studied area would be still increasing. As in other studies, female adolescents had a higher prevalence of current asthma. Current active tobacco smoking has strikingly increased in the studied children while indoor passive tobacco exposure remains inadmissibly high. Our findings suggest that asthma in children is underdiagnosed and undertreated. More attention should be given to female gender, tobacco exposure, air pollution and local diagnostic preferences when studying and interpreting trends of asthma prevalence in adolescents from developing localities.

Increased prevalence of exercise-induced airway symptoms - A five-year follow-up from adolescence to young adulthood

BACKGROUND

Exercise-induced airway symptoms are common in adolescents. Little is known about the development of symptoms from adolescence to early adulthood. Therefore, we studied the prevalence, incidence, and remission of exercise-induced airway symptoms (including wheeze, cough, chest and throat tightness, hoarseness, and stridor) in adolescents, over a five-year period.

METHODS

In 2011, all adolescents aged 12-13 years in Uppsala (n = 3 838) were invited to answer a questionnaire on exercise-induced airway symptoms. All responding adolescents (n = 2 309) were invited to answer the same questionnaire again after five years. In total, 1 002 adolescents responded (43.4%).

RESULTS

The prevalence of exercise-induced airway symptoms increased from 25% at baseline to 49% at follow-up (p < 0.001). More females than males reported symptoms at both time points. The incidence of airway symptoms was 42.2%, with no sex differences. More males than females reported symptom remission (20.2 vs. 10.7%, p < 0.001). Females reported a higher asthma prevalence at follow-up than at baseline (7.6 vs. 15.2%), while males did not (10.9 vs. 8.0%), leading to a sex difference in prevalence at follow-up (p < 0.001). Smoking and baseline respiratory symptoms were associated with an increased risk of reporting symptoms at follow-up.

CONCLUSIONS

A twofold increase in the prevalence of exercise-induced airway symptoms over a five-year period was found in this cohort. Females were more likely to report symptoms at both time points. Knowledge of these age-related changes in symptoms and their association to female gender is useful for future studies and healthcare providers.

Community-based survey as a basis for evidence-based public health: children living in Upper Silesian Industrial Zone

OBJECTIVE

The aim of the study was to estimate changes in the prevalence of respiratory diseases and disorders between 2003/2004 and 2011/2012 in 13-16 years old children living in Bytom, one of the biggest cities in the Silesia agglomeration and provide the evidence for local policy makers.

METHODS

Data from two cross-sectional surveys, based on the Polish version of the International Study of Allergy and Asthma in Childhood (ISAAC) questionnaire, conducted in 2003/2004 and 2011/2012 was used. Response rate in the first and the second survey was 68% and 35%, respectively. The number of analyzed observations was 4,041 and 707 from the first and the second survey. The selection bias was controlled with the propensity score matching and potential determinants of analyzed respiratory diseases and disorders were controlled in the multivariable logistic regression model.

RESULTS

We found statistically significant increase in asthma ever diagnosed by medical doctor (4.5% vs. 9.6%; p < 0.01), seizures of dyspnea (8.2% vs. 27.7%; p < 0.01), and chest wheeze (9.6% vs. 19.2%; p < 0.01).

CONCLUSION

Our study revealed significant increase in the prevalence of respiratory diseases and disorders after 8 years in adolescents living in the Upper Silesian Industrial Zone. This is a relevant finding which provides the evidence for decision makers in the scope of local public health policies.

Sublingual allergen immunotherapy for respiratory allergy: a systematic review

The objective of the systematic review is to provide complete and updated information on efficacy and safety of sublingual immunotherapy (SLIT) formulations for the treatment of allergic respiratory diseases (ARDs). The literature search was conducted on PubMed database, involving double-blind, randomized clinical trials published between January 1992 and 2018, written in English, and performed in humans. The number of articles finally selected for review was 112. Data from the majority of properly controlled clinical trials demonstrate that SLIT is effective not only with short-term use (first year) but also with long-term use (up to the third year of active therapy), for treating ARDs in children and adults. Both continuous and discontinuous schemes of administration showed significant reductions in symptom and medication scores. Moreover, a SLIT-induced disease-modifying effect has been documented mainly with grass pollen extracts, since improvement is maintained during at least 2 years of follow-up after a 3-year treatment period. Additionally, allergen immunotherapy should also be considered a preventive strategy, especially for decreasing bronchial asthma incidence in children and adolescents with allergic rhinitis treated with SLIT. This therapy is also safe, producing only a few mainly local and mild-to-moderate adverse events, and usually self-limited in time. The registration and authorization of allergen SLIT preparations (grasses and house-dust mite tablets) as drugs by regulatory agencies, such as the United States Food and Drug Administration (FDA) and the European Medicines Agency (EMA), has represented a landmark in allergy immunotherapy research. Further long-term studies, specially designed with allergens other than grass pollen or house-dust mites, not only in allergic rhinoconjunctivitis but also on asthmatic subjects, as well as studies comparing different administration schedules and/or routes, are required in order to continue the progress in the modern development of this particularly promising therapy.

Mechanisms of organophosphorus pesticide toxicity in the context of airway hyperreactivity and asthma

Numerous epidemiologic studies have identified an association between occupational exposures to organophosphorus pesticides (OPs) and asthma or asthmatic symptoms in adults. Emerging epidemiologic data suggest that environmentally relevant levels of OPs may also be linked to respiratory dysfunction in the general population and that in utero and/or early life exposures to environmental OPs may increase risk for childhood asthma. In support of a causal link between OPs and asthma, experimental evidence demonstrates that occupationally and environmentally relevant OP exposures induce bronchospasm and airway hyperreactivity in preclinical models. Mechanistic studies have identified blockade of autoinhibitory M2 muscarinic receptors on parasympathetic nerves that innervate airway smooth muscle as one mechanism by which OPs induce airway hyperreactivity, but significant questions remain regarding the mechanism(s) by which OPs cause neuronal M2 receptor dysfunction and, more generally, how OPs cause persistent asthma, especially after developmental exposures. The goals of this review are to 1) summarize current understanding of OPs in asthma; 2) discuss mechanisms of OP neurotoxicity and immunotoxicity that warrant consideration in the context of OP-induced airway hyperreactivity and asthma, specifically, inflammatory responses, oxidative stress, neural plasticity, and neurogenic inflammation; and 3) identify critical data gaps that need to be addressed in order to better protect adults and children against the harmful respiratory effects of low-level OP exposures.

An international comparison of asthma, wheeze, and breathing medication use among children

BACKGROUND

There is variation in childhood asthma between countries with typically higher prevalence in "Westernized" nations. We compared asthma, respiratory symptoms, and medication prevalence in Eastern and Central European regions and Canada.

METHODS

We conducted a cross-sectional survey study of children (5-15 years) from one urban centre in each of Canada, Belarus, Poland, Republic of Georgia (Adjara), Republic of Macedonia, and Ukraine. Surveys were distributed through randomly selected schools to parents (2013-2015).

RESULTS

The prevalence of asthma differed by country from 20.6% in Canada to 1.5% in Ukraine (p < 0.001). This association remained after confounder adjustment. Except for Canada (58.7%) and Poland (42.5%), less than 10% of children with a history of wheeze had a diagnosis of asthma. Regardless of country, more than 50% of children with a diagnosis of asthma used breathing medications in the past year. Finally, except for Georgia (12.1%), all countries had a prevalence of ever wheeze above 20% (23.8% in Poland to 30.9% in Macedonia).

CONCLUSIONS

Despite large differences in asthma prevalence, respiratory morbidity was more comparable suggesting asthma prevalence may be underestimated. Further validation of asthma diagnosis is needed. It is important to promote best diagnostic practices among first contact physicians.

Plasma Cluster Ions Reduce the IgE-Binding Capacity of House Dust Mite Allergens under a Simulated Indoor Environmental Condition

BACKGROUND

A high level of house dust mite (HDM) allergens in a living environment is a risk factor for both sensitization to these allergens and asthmatic attacks. We previously showed that plasma cluster ions (PCIs) impaired the IgE-binding capacity of atomized crude allergens prepared from Japanese cedar pollen and fungus under experimental conditions.

OBJECTIVE

We evaluated the capacity of PCIs to impair the IgE-binding capacity of airborne HDM allergens under a simulated indoor environmental condition.

METHODS

For the determination of the effects of PCIs on HDM allergens under an experimental condition, HDM extract was atomized as aqueous mist into a cylindrical experimental apparatus filled with PCIs. For the evaluation of the effects of PCIs under a simulated natural indoor environmental condition, dried HDM allergens were floated as airborne particles in an acryl cubic apparatus in the presence of PCIs. The IgE-binding capacities of the PCI- and sham-treated HDM allergens were analyzed by an ELISA.

RESULTS

The IgE-binding capacity of the HDM allergens was significantly impaired after PCI treatment compared to that after sham treatment under both experimental and simulated environmental conditions. The ELISA results demonstrated that the IgE-binding capacities of HDM allergens after PCI treatment showed 68 and 74% reductions compared to those after sham treatment under the experimental and simulated environmental conditions, respectively.

CONCLUSIONS

PCIs have the capacity to impair the IgE-binding capacity of airborne HDM allergens in a simulated environmental condition.

The Trend of Change of Allergic Diseases over the Years: Three Repeated Surveys from 1994 to 2014

BACKGROUND

Although it is known that there has been an increase in asthma and allergic diseases among school-aged children, results vary between countries. The aim of this study was to examine trends in the prevalence of these diseases in the city of Adana (south Turkey) over the last 20 years based on the results of 3 cross-sectional studies.

METHODS

Three cross-sectional surveys were performed 10 years apart in south Turkey. Here, we compare the surveys conducted among children between the ages of 6 and 14 years from 1994, 2004, and 2014. The participants were randomly chosen among children attending participating primary schools in Adana. The questionnaire in the first survey contained almost the same questions as the ISAAC. In the 2 latter surveys, we used the ISAAC questionnaire to investigate the prevalence of asthma and other allergic diseases.

RESULTS

A total of 2,334 children in 1994, 3,728 children in 2004, and 3,209 children in 2014 were included in the final analysis. The results showed a statistically significant increase in the prevalence of physician-diagnosed allergic diseases across the years, respectively: asthma (5, 4.6, and 8.9%), allergic rhinitis (8.8, 11.4, and 15.6%), and atopic dermatitis (5, 9.9, and 7%). In contrast, the prevalence of parent-reported current wheeze (16.2, 13.2%) decreased in the last 10 years.

CONCLUSIONS

Our findings were consistent with the increased prevalence of childhood asthma and other allergic diseases. However, this pattern did not occur in respiratory symptoms.

Diagnosing allergic sensitizations in the third millennium: why clinicians should know allergen molecule structures

Diagnostic tests to detect allergic sensitization were introduced at the end of the nineteenth century but only in the late 1990s did the advent of molecular allergology revolutionize the approach to the allergic patient. Personalized Medicine, a medical procedure that separates patients into different groups with different medical decisions, practices and interventions has sanctioned this change. In fact, in the last few years molecular allergology and the observation that not every patient has the same allergic profile, even when allergic to the same allergenic source, has originated the concept "one size does not fit all". This new approach requires the identification of still unknown allergens, but also the more detailed investigation of those already known. In depth studies of the structure-function relationships in allergenic molecules can reveal the structural determinants involved in the IgE-binding. Then, the knowledge of the epitope profile of each allergen and of the environmental/experimental conditions affecting the exposure of IgE-binding epitopes can provide important contributions to the understanding of cross-reaction processes and to the improvement of diagnosis, immunotherapy and the overall patient treatment. The evolution of diagnostic systems cannot ignore these new needs in this field.

Allergen sensitization affected the change trend of prevalence of symptoms of rhinitis coexisting with wheeze among adolescents in Guangzhou City from 1994 to 2009

BACKGROUND

Few studies have assessed the time trends of prevalence of symptoms of rhinitis (SR) with wheezing and their associations in Chinese adolescents.

OBJECTIVE

To explore the trend of prevalence of SR with wheezing and allergen sensitization in adolescents during the past 15 years.

METHODS

A total of 6928 adolescents aged 13-14 years in 2009 were recruited for the study using the Phase III Protocol of the International Study of Asthma and Allergic disease in Childhood (ISAAC) and allergic sensitization to seven inhalant allergens in 2531 was assessed by skin prick test in 2010. The results were compared to those obtained in the Phase I (1994/95) and III (2001/02) ISAAC studies.

RESULTS

The prevalence of 'SR ever' and 'current symptoms of rhino-conjunctivitis' increased from 46.3% and 8.7% in 1994 to 53.2% and 11.1% in 2001 (p < 0.001), respectively, and remained stable at 52.6% and 10.4% in 2009 (p > 0.05). The prevalence of 'SR ever and wheeze ever' and 'SR ever and current wheeze' increased from 6.2% and 3.4% in 1994 to 8.6% and 4.8% in 2001 (p < 0.001) to 10.9% and 5.9% in 2009 (p < 0.05). The sensitization rate to common inhaled allergens was higher in 2010 than in 2002 (p < 0.001). Sensitization to house dust mites (HDMs) was associated with increases in the prevalence of SR (OR, 2.06-2.86), especially with coexistence of wheeze (OR, 6.07-7.43).

CONCLUSION

The prevalence of symptoms of rhinitis and coexistence with wheezing has increased significantly since 1994. Sensitization to HDMs is the main risk factor associated with this increase.

The Hokkaido Birth Cohort Study on Environment and Children's Health: cohort profile-updated 2017

The Hokkaido Study on Environment and Children's Health is an ongoing study consisting of two birth cohorts of different population sizes: the Sapporo cohort and the Hokkaido cohort. Our primary study goals are (1) to examine the effects of low-level environmental chemical exposures on birth outcomes, including birth defects and growth retardation; (2) to follow the development of allergies, infectious diseases, and neurobehavioral developmental disorders and perform a longitudinal observation of child development; (3) to identify high-risk groups based on genetic susceptibility to environmental chemicals; and (4) to identify the additive effects of various chemicals, including tobacco smoking. The purpose of this report is to update the progress of the Hokkaido Study, to summarize the recent results, and to suggest future directions. In particular, this report provides the basic characteristics of the cohort populations, discusses the population remaining in the cohorts and those who were lost to follow-up at birth, and introduces the newly added follow-up studies and case-cohort study design. In the Sapporo cohort of 514 enrolled pregnant women, various specimens, including maternal and cord blood, maternal hair, and breast milk, were collected for the assessment of exposures to dioxins, polychlorinated biphenyls, organochlorine pesticides, perfluoroalkyl substances, phthalates, bisphenol A, and methylmercury. As follow-ups, face-to-face neurobehavioral developmental tests were conducted at several different ages. In the Hokkaido cohort of 20,926 enrolled pregnant women, the prevalence of complicated pregnancies and birth outcomes, such as miscarriage, stillbirth, low birth weight, preterm birth, and small for gestational age were examined. The levels of exposure to environmental chemicals were relatively low in these study populations compared to those reported previously. We also studied environmental chemical exposure in association with health outcomes, including birth size, neonatal hormone levels, neurobehavioral development, asthma, allergies, and infectious diseases. In addition, genetic and epigenetic analyses were conducted. The results of this study demonstrate the effects of environmental chemical exposures on genetically susceptible populations and on DNA methylation. Further study and continuous follow-up are necessary to elucidate the combined effects of chemical exposure on health outcomes.

Childhood asthma in Batumi, Georgia: Prevalence and environmental correlates

OBJECTIVE

A relative lack of data for Eastern Europe and unknown epidemiology of childhood asthma in Batumi (Georgia) justified a study aimed at determining the prevalence of physician-diagnosed asthma and related respiratory conditions, a comparison of the prevalence of these conditions between urban and rural children, and identification of their environmental correlates.

METHODS

Subjects of the cross-sectional population-based study were 3238 urban and 2081 rural children aged 5-17 years whose respiratory status was assessed using the ISAAC questionnaire.

RESULTS

The overall prevalence of asthma was larger in rural children than in urban children (2.8% vs. 1.8%, respectively; p = 0.01). Spastic bronchitis occurred with similar frequency in urban (7.8%) and rural children (6.5%). Compared with urban children, rural subjects had dry cough at night (13.1 vs 8.2%, p < 0.001) and attacks of dyspnea (4.7 vs 2.4%, p < 0.001) more often. The prevalence of other symptoms did not differ significantly between urban and rural subjects. Results of multivariate analyses showed that both asthma and spastic bronchitis were associated (p < 0.05) with parental history of asthma, dampness in the house, and poor financial standing of the family. In addition, asthma was related to coal/wood-based heating whereas spastic bronchitis was associated with passive smoking and lower parental education.

CONCLUSIONS

The findings show a low prevalence of ever-diagnosed asthma in the examined population. Nosological tradition and similar correlates of asthma and spastic bronchitis suggest that some cases of asthma might be included in the diagnostic category of spastic bronchitis.