The Asian side of asthma and allergy

Risk of Incident Asthma Among Young Asian American, Native Hawaiian, and Pacific Islander Children from Age 3 to 7 Years in a Northern California Healthcare System

Incident childhood asthma risk has not been examined among diverse Asian American, Native Hawaiian, and Pacific Islander subgroups. In a large California healthcare system, incident asthma was higher among young Filipino/a, Native Hawaiian/Pacific Islander, and South Asian children compared with non-Hispanic White children, whereas Chinese and Japanese children were similar.

Clinical predictors of wheeze trajectories and associations with allergy in Asian children

BACKGROUND

Childhood wheezing is a highly heterogeneous condition with an incomplete understanding of the characteristics of wheeze trajectories, particularly for persistent wheeze.

OBJECTIVE

To characterize predictors and allergic comorbidities of distinct wheeze trajectories in a multiethnic Asian cohort.

METHODS

A total of 974 mother-child pairs from the prospective Growing Up in Singapore Towards healthy Outcomes (GUSTO) cohort were included in this study. Wheeze and allergic comorbidities in the first 8 years of life were assessed using the modified International Study of Asthma and Allergies in Childhood questionnaires and skin prick tests. Group-based trajectory modeling was used to derive wheeze trajectories and regression was used to assess associations with predictive risk factors and allergic comorbidities.

RESULTS

There were 4 wheeze trajectories derived, including the following: (1) early-onset with rapid remission from age 3 years (4.5%); (2) late-onset peaking at age 3 years and rapidly remitting from 4 years (8.1%); (3) persistent with a steady increase to age 5 years and high wheeze occurrence until 8 years (4.0%); and (4) no or low wheeze (83.4%). Early-onset wheezing was associated with respiratory infections during infancy and linked to subsequent nonallergic rhinitis throughout childhood. Late-onset and persistent wheeze shared similar origins characterized by parent-reported viral infections in later childhood. However, persistent wheezing was generally more strongly associated with a family history of allergy, parent-reported viral infections in later childhood, and allergic comorbidities as compared with late-onset wheezing.

CONCLUSION

The timing of viral infection occurrence may determine the type of wheeze trajectory development in children. Children with a family history of allergy and viral infections in early life may be predisposed to persistent wheeze development and the associated comorbidities of early allergic sensitization and eczema.

The efficacy of sublingual immunotherapy for allergic diseases in Asia

Sublingual immunotherapy (SLIT) has been proven to be safe and effective from an abundance of Western literature, but data from Asia is less complete. This review aims to examine the basic science, safety and efficacy of SLIT in Asian patients, and to determine future research needs in Asia. We performed a literature search on PUBMED, Scopus, and Cochrane Library database for articles on SLIT originating from Asian countries through Nov 2017. There were 18 randomized, double-blind, placebo-controlled trials, of which 9 involved solely paediatric subjects. Overall, sublingual immunotherapy is safe and is efficacious in Asian populations in allergic rhinitis (AR) and asthma. House dust-mite SLIT is effective in both mono- and polysensitized AR patients. Efficacy of SLIT is comparable to subcutaneous immunotherapy. Data on long term efficacy is lacking. A disproportionate majority of research originates from China and Japan, reflecting an asymmetry of access to SLIT within Asia. Significant disparities exist in the development of the allergy speciality, prescription patterns of SLIT, and pharmacological potencies of different SLIT products within and between Asian nations. We conclude that current available evidence suggests SLIT is efficacious in Asians but data quality of evidence is hampered by non-placebo controlled studies with methodological limitations. More data is needed in South and Southeast Asian populations. Future efforts may be directed towards improving access to SLIT in developing countries, standardization of SLIT dosage, and evaluating long term clinical outcomes.

The 100 most influential publications in asthma from 1960 to 2017: A bibliometric analysis

BACKGROUND

The area of asthma medicine has produced a large volume of important clinical and scientific papers that can be found in those most influential journals. The purpose of our study was to identify the 100 most cited papers in asthma research and to analyze their characteristics.

METHODS

We used the Institute for Scientific Information Web of Knowledge Database to identify the most frequently cited articles published from 1960 to December 2017. Original articles and reviews were included in the study. The 100 top-cited articles were then analyzed with regard to number of citations, publication year, journals, institution, research type and field, authors and countries of authors of publications.

RESULTS

The 100 top-cited articles in asthma were published between 1960 and 2011 with a median of 933 citations per article (range, 701-2947). The number of citations per article was greatest for articles published in the 1990s. The United States of America contributed most of the classic articles, followed by England. The leading institutions were Imperial College London, McMaster University, Erasmus University Rotterdam. The 100 top-cited articles were published in twenty-five journals, led by The New England Journal of Medicine (21 articles), followed by American Journal of Respiratory and Critical Care Medicine (19 articles), Lancet (11 articles), respectively. Among the 100 classics, 50% articles were clinical research articles.

CONCLUSIONS

Our study provides a historical perspective on the progress of research on asthma. Studies conducted in well-developed European countries and North America, published in high-impact journals had the highest citations.

A Review of the Effects of Major Atmospheric Pollutants on Pollen Grains, Pollen Content, and Allergenicity

This review summarizes the available data related to the effects of air pollution on pollen grains from different plant species. Several studies carried out either on in situ harvested pollen or on pollen exposed in different places more or less polluted are presented and discussed. The different experimental procedures used to monitor the impact of pollution on pollen grains and on various produced external or internal subparticles are listed. Physicochemical and biological effects of artificial pollution (gaseous and particulate) on pollen from different plants, in different laboratory conditions, are considered. The effects of polluted pollen grains, subparticles, and derived aeroallergens in animal models, in in vitro cell culture, on healthy human and allergic patients are described. Combined effects of atmospheric pollutants and pollen grains-derived biological material on allergic population are specifically discussed. Within the notion of "polluen," some methodological biases are underlined and research tracks in this field are proposed.

Environmental Exposure and Genetic Predisposition as Risk Factors for Asthma in China

Asthma is the most common chronic pulmonary disease worldwide and places a considerable economic burden on society. China is the world's largest developing country and has the largest population. China has undergone dramatic changes in the past few decades. The traditional lifestyle and living environment have changed in ways that directly affect the prevalence of asthma. The prevalence of asthma is lower in Chinese children and adults than in developed countries, but the prevalence has been on the rise during the past 30 years. The prevalence significantly varies among different parts of China. Polymorphisms of multiple genes, outdoor air pollution caused by PM2.5, PM10, SO₂, NO₂, environmental tobacco smoke, and coal, indoor pollution, and inhaled allergens, such as house dust mites, pollen, and cockroach particles, are risk factors for asthma.

Pediatric asthma control in Asia: phase 2 of the Asthma Insights and Reality in Asia-Pacific (AIRIAP 2) survey

BACKGROUND

We conducted Phase 2 of the Asthma Insights and Reality in the Asia-Pacific (AIRIAP 2) survey in 2006 to determine the level of asthma control in this region and the validity of the Asthma Control Test (ACT) and childhood ACT (C-ACT) in relation to asthma control.

METHODS

Pediatric participants (0 to <16 years; N = 988) with diagnosed asthma and current asthma symptoms or taking anti-asthma medications were recruited from 12 geographic areas in Asia. The survey consisted of the AIRIAP 2 questionnaire (asthma symptoms, use of urgent healthcare services and anti-asthma medication) and the ACT or C-ACT (English or Chinese translations only), both administered in the participant's preferred language. A symptom control index based on the Global Initiative for Asthma criteria (except lung function) was used to classify asthma control status.

RESULTS

Most participants had inadequately controlled asthma ('uncontrolled' = 53.4%, 528/988; 'partly controlled' = 44.0%, 435/988). Only 2.5% (25/988) had 'controlled' asthma. Demand for urgent healthcare services (51.7%, 511/988) and use of short-acting beta-agonists (55.2%, 545/988) was high. The optimal ACT and C-ACT cutoff score for detecting uncontrolled asthma (compared with controlled or partly controlled asthma) was determined to be ≤19 (receiver operating characteristic analysis) with good agreement between the ACT and C-ACT and the symptom control index.

CONCLUSIONS

Findings from this survey show that asthma control is suboptimal in many children in the Asia-Pacific region. Practical tools, such as the ACT or C-ACT, may help clinicians assess asthma control and facilitate adjustment of asthma medication.

Changing prevalence of allergic diseases in the Asia-pacific region

Asia-Pacific is one of the most densely populated regions of the world and is experiencing rapid economic changes and urbanization. Environmental pollution is a significant problem associated with the rapid modernization of many cities in South Asia. It is not surprising that the prevalences of asthma and allergies are increasing rapidly, although the underlying reasons remain largely unknown. Many studies from this region have documented the changing prevalence of allergic diseases in various parts of the world. However, the methodologies used were neither standardized nor validated, making the results difficult to evaluate. The International Study of Asthma and Allergies in Childhood (ISAAC) has provided a global epidemiology map of asthma and allergic diseases, as well as the trend of changes in the prevalence of these diseases. Allergic sensitization is extremely common in many Asian communities. However, the prevalence of allergic diseases remains relatively rare. The rapid urbanization in the region, which increases environmental pollution and can affect the rural environment, will likely increase the prevalence of asthma and allergies in Asia.

The methodology of the GUSTO cohort study: a novel approach in studying pediatric allergy

Growing Up in Singapore Towards healthy Outcomes (GUSTO) is Singapore's largest birth cohort study to date. The main aim of GUSTO is to evaluate the role of developmental factors in the early pathways to metabolic compromise. Detailed data is collected for a range of environmental exposures in the parents and offspring, and allergic disorders are among a number of outcomes assessed in infancy and childhood. Under the Allergy domain of GUSTO, this integrated study will describe the epidemiology of allergic manifestations and different phenotypes in the Asian context and help shed light on the association of metabolic disease to allergy. Epigenetic mechanisms and associations with other childhood disorders will also be explored. The aim of this report is to focus on methodology of GUSTO, and to suggest similar approaches (i.e., integrated cohort studies on pediatric allergy) worldwide. Recruitment commenced in 2009 with a cohort of 1,163 pregnant mothers in their first trimester. The mothers and children were followed throughout pregnancy and follow-up will continue until the child reaches 3 years of age. Preliminary results showed that 39.8% of the mothers had a personal history of having at least one allergic disease, which included asthma, eczema and allergic rhinitis. Further data collection and analyses are still ongoing. Allergy is a complex spectrum of disorders with numerous poorly-understood aspects. The ongoing GUSTO cohort study, with its longitudinal design and multi-disciplinary nature, may provide new insights into developmental influences on allergy. As a Singapore-based study, it will be the first integrated allergy cohort in Southeast Asia, of which recruitment started during pregnancy.

Gender differences and effect of air pollution on asthma in children with and without allergic predisposition: northeast Chinese children health study

Background

Males and females exhibit different health responses to air pollution, but little is known about how exposure to air pollution affects juvenile respiratory health after analysis stratified by allergic predisposition. The aim of the present study was to assess the relationship between air pollutants and asthmatic symptoms in Chinese children selected from multiple sites in a heavily industrialized province of China, and investigate whether allergic predisposition modifies this relationship.

Methodology/Principal Findings

30139 Chinese children aged 3-to-12 years were selected from 25 districts of seven cities in northeast China in 2009. Information on respiratory health was obtained using a standard questionnaire from the American Thoracic Society. Routine air-pollution monitoring data was used for particles with an aerodynamic diameter ≤10 µm (PM₁₀), sulfur dioxide (SO₂), nitrogen dioxides (NO₂), ozone (O₃) and carbon monoxide (CO). A two-stage regression approach was applied in data analyses. The effect estimates were presented as odds ratios (ORs) per interquartile changes for PM₁₀, SO₂, NO₂, O₃, and CO. The results showed that children with allergic predisposition were more susceptible to air pollutants than children without allergic predisposition. Amongst children without an allergic predisposition, air pollution effects on asthma were stronger in males compared to females; Current asthma prevalence was related to PM₁₀ (ORs = 1.36 per 31 µg/m³; 95% CI, 1.08–1.72), SO₂ (ORs = 1.38 per 21 µg/m³; 95%CI, 1.12–1.69) only among males. However, among children with allergic predisposition, more positively associations between air pollutants and respiratory symptoms and diseases were detected in females; An increased prevalence of doctor-diagnosed asthma was significantly associated with SO₂ (ORs = 1.48 per 21 µg/m³; 95%CI, 1.21–1.80), NO₂ (ORs = 1.26 per 10 µg/m³; 95%CI, 1.01–1.56), and current asthma with O₃ (ORs = 1.55 per 23 µg/m³; 95%CI, 1.18–2.04) only among females.

Conclusion/Significance

Ambient air pollutions were more evident in males without an allergic predisposition and more associations were detected in females with allergic predisposition.

A Japanese case series of 12 patients with esophageal eosinophilia

BACKGROUND

Eosinophilic esophagitis (EoE) has been a rarely recognized condition in Asian populations, and its clinical manifestation is rarely documented. Our aim was to describe clinically, endoscopically, and pathologically the features of patients with esophageal eosinophilia, including EoE.

METHODS

Twelve patients histologically proven to have esophageal eosinophilia were investigated. The histological diagnostic cutoff value was defined as a peak of ≥15 eosinophils/high-power field (HPF) in esophageal biopsies. Symptoms, endoscopic and pathological findings, and treatment outcome were evaluated.

RESULTS

Nine of the 12 patients were male and the 12 patients had a mean age of 47.7 years. Allergic conditions were concurrent in a total of 3 patients. Mild peripheral eosinophilia was observed in only 2 patients. The predominant symptom was solid-food dysphagia, but some patients complained of heartburn, or chest, epigastric, or back pain. Three asymptomatic subjects were also incidentally diagnosed during endoscopic screening. Linear furrows, concentric rings, and white exudates in the esophagus were frequently observed. In 4 of 5 patients who were administered a proton pump inhibitor (PPI), esophageal eosinophilia was histologically decreased or disappeared with symptom relief and endoscopic improvement. In 2 patients unresponsive to PPI, topical steroid therapy, administered by the swallowing of fluticasone propionate, led to symptomatic and histological remission.

CONCLUSIONS

The endoscopic recognition of linear furrows, concentric rings, and white exudates is important in the diagnosis of eosinophilic esophageal inflammation. In a subset of patients this condition improves clinicopathologically with PPI treatment, and typical EoE, as strictly defined by unresponsiveness to PPI, appears to be a rather rare condition.

Allergies in Asia: differences in prevalence and management compared with western populations

There is wide variability in the epidemiology and management of childhood asthma and related atopic diseases globally. Urbanized, affluent Western countries tend to have a higher prevalence of these diseases compared with Asian nations. However, recent studies have shown that the prevalence in Asia is increasing, although the rate of increase has slowed in the more developed Asian cities. Some possible causes for these differences are socioeconomic status, degree of urbanization, rates of infection, healthcare practices and genetic factors. Importantly, there are significant differences in the way asthma and allergic diseases are managed within Asia. This is of great concern because of the health implications, as these diseases are some of the most common chronic conditions that affect both adults and children. This review compares the differences in prevalence and management between Asia and the West, and discusses some of the possible reasons behind these variations.

Hypersensitivity to Pollen of Olea Europea in Patients with Pollen Allergy in Zadar County, Croatia

Preosjetljivost na pelud masline važan je uzrok peludnih alergija u mediteranskim zemljama. Cilj ovoga rada bio je utvrditi učestalost preosjetljivosti na pelud masline među bolesnicima s peludnom alergijom u Zadru i Zadarskoj županiji. Dobivene rezultate usporedili smo s ranijim ispitivanjem preosjetljivosti na pelud masline u Dalmaciji.

Ukupno je obrađen 671 ispitanik s preosjetljivosti na peludne alergene. Od toga broja 61 % ispitanika bilo je muškog spola, a 39 % je bilo ženskog spola. Od ukupno ispitanih 53.5 % činila su djeca u dobi od 4 do 14 godina, a preostalih 46.5 % bili su odrasli u dobi od 15 do 59 godina života. Svim ispitanicima uzeta je detaljna obiteljska i osobna anamneza, napravljen klinički pregled te učinjeno kožno prick-testiranje i enzimatsko-imunološki UniCAP-test za određivanje specifičnih IgE-protutijela. Statistička obrada podataka učinjena je χ2-testom.

Preosjetljivost na pelud masline dokazana je u 8.8 % bolesnika s peludnom alergijom. Najveći broj bolesnika s preosjetljivosti na pelud masline boluje od alergijskog rinitisa, 58 % bolesnika. Postoji statistički značajna razlika u broju bolesnika između dvije ispitivane sredine, gradske i seoske. Samo 3 % bolesnika stanovnici su otoka.

Preosjetljivost na pelud masline u našem ispitivanju najniža je u odnosu na ispitivanja provedena u drugim mediteranskim zemljama. Najčešće se očituje kliničkom slikom alergijskog rinitisa, a statistički je značajno češća u gradskoj sredini. Usporedba preosjetljivosti na pelud masline tijekom dvaju ispitivanih razdoblja u našoj zemlji nije pokazala porast broja bolesnika s preosjetljivosti na pelud masline.

Risk for asthma in offspring of asthmatic mothers versus fathers: a meta-analysis

BACKGROUND

Many human epidemiologic studies demonstrate that maternal asthma confers greater risk of asthma to offspring than does paternal disease. However, a handful have shown the opposite. Given this disparity, a meta-analysis is necessary to determine the veracity and magnitude of the "maternal effect."

METHODOLOGY/PRINCIPAL FINDINGS

We screened the medical literature from 1966 to 2009 and performed a meta-analysis to compare the effect of maternal asthma vs. paternal asthma on offspring asthma susceptibility. Aggregating data from 33 studies, the odds ratio for asthma in children of asthmatic mothers compared with non-asthmatic mothers was significantly increased at 3.04 (95% confidence interval: 2.59-3.56). The corresponding odds ratio for asthma in children of asthmatic fathers was increased at 2.44 (2.14-2.79). When comparing the odds ratios, maternal asthma conferred greater risk of disease than did paternal asthma (3.04 vs. 2.44, p = 0.037). When analyzing the studies in which asthma was diagnosed by a physician the odds ratios were attenuated and no significant differences were observed (2.85 vs. 2.48, N = 18, p = 0.37). Similarly, no significant differences were observed between maternal and paternal odds ratios when analyzing the studies in which the patient population was 5 years or older (3.15 vs. 2.60, p = 0.14). However, in all cases the trend remained the same, that maternal asthma was a greater risk factor for asthma than paternal.

CONCLUSIONS/SIGNIFICANCE

The results show that maternal asthma increases offspring disease risk to a greater extent than paternal disease.

Asthma research performance in Asia-Pacific: a bibliometric analysis by searching PubMed database

BACKGROUND AND OBJECTIVE

Countries in the Asia-Pacific region have experienced an increase in the prevalence of asthma, and they have been actively involved in asthma research recently. This study aimed to analyze asthma research from Asia-Pacific in the last decade by bibliometric method.

METHOD

Asthma articles from Asia-Pacific countries published between 1998 and 2007 were retrieved from PubMed by searching MeSH for "asthma."

RESULTS

Most of published asthma articles in Asia-Pacific are from affluent countries in northeast Asia and Oceania. Australia and Japan have been the regional powerhouses since they contributed more than half of regional articles on asthma. Asthma publications from emerging economies in Asia such as South Korea, Taiwan, Hong Kong, and Singapore, have dramatically increased in the last decade in terms of quantity and quality aspects and were considerable sources of basic and translational research in the region. Mainland China and India have significantly increased their research capacity as well, but quality needs to be improved. Asthma publications from New Zealand and Australia, countries with the highest asthma prevalence rates in the world, yielded highest citation counts per articles and were published in journals with high impact factor. Asthma research parameters per million population correlate well with gross domestic product per capita. Almost half (41%) of total articles were produced from only 25 institutions in the region and almost half of them (47%) were published in 20 journals.

CONCLUSIONS

Asthma research in Asia-Pacific were mainly conducted in countries in Oceania and Northeast Asia and research performance strongly correlated with the nation's wealth. Interesting asthma research projects in the region were recommended.

What have we learnt from ISAAC phase III in the Asia-Pacific rim?

PURPOSE OF REVIEW

International Study of Asthma and Allergies in Childhood (ISAAC) phase III had provided a worldwide map of epidemiology of asthma and allergic diseases, as well as the changes in prevalence rate of these diseases when compared to data obtained in phase I. The wide variations of environmental factors and ethnic background in Asia provide excellent opportunities for research into the environmental and genetic determinants of asthma and allergies. This review summarizes important lessons learnt from ISAAC phase III results from Asia on asthma and allergy.

RECENT FINDINGS

ISAAC phase III provided epidemiological evidence of the wide variation and increasing prevalence of asthma and allergy in many Asian countries. When compared to other regions of the world, Asia has a relatively lower prevalence of asthma and allergic diseases. Comparative studies of populations of the same ethnic group living in different environments reveal striking disparity in prevalence of asthma and allergic diseases. The established risk factors could not explain the secular trend and variations of asthma prevalence in different Asian countries. Further research is needed in this rapidly changing region of Asia in order to identify the protective or risk factors associated with the development of asthma.

SUMMARY

ISAAC phase III provides standardized data on the prevalence and burden of asthma and allergy in the Asia-Pacific region. Further research is needed to reveal the underlying factors responsible for the wide variations in disease manifestations in the region.