A cross-sectional observational study on allergen-specific IgE positivity in a southeast coastal versus a southwest inland region of China

Changing clinical characteristics of pediatric inpatients with pneumonia during COVID-19 pandamic: a retrospective study

BACKGROUND

The COVID-19 pandemic have impacts on the prevalence of other pathogens and people's social lifestyle. This study aimed to compare the pathogen, allergen and micronutrient characteristics of pediatric inpatients with pneumonia prior to and during the COVID-19 pandemic in a large tertiary hospital in Shanghai, China.

METHODS

Patients with pneumonia admitted to the Department of Pediatric Pulmonology of Xinhua Hospital between March-August 2019 and March-August 2020 were recruited. And clinical characteristics of the patients in 2019 were compared with those in 2020.

RESULTS

Hospitalizations for pneumonia decreased by 74% after the COVID-19 pandemic. For pathogens, virus, mycoplasma pneumoniae (MP) and mixed infection rates were all much lower in 2020 than those in 2019 (P < 0.01). Regarding allergens, compared with 2019, the positive rates of house dust mite, shrimp and crab were significantly higher in 2020 (P < 0.01). And for micronutrients, the levels of vitamin B2, B6, C and 25-hydroxyvitamin D (25(OH)D) in 2020 were observed to be significantly lower than those in 2019 (P < 0.05). For all the study participants, longer hospital stay (OR = 1.521, P = 0.000), milk allergy (OR = 6.552, P = 0.033) and calcium (Ca) insufficiency (OR = 12.048, P = 0.019) were identified as high-risk factors for severe pneumonia by multivariate analysis.

CONCLUSIONS

The number of children hospitalized with pneumonia and incidence of common pathogen infections were both reduced, and that allergy and micronutrient status in children were also changed after the outbreak of the COVID-19 pandemic.

Allergen immunotherapy in China

Allergen immunotherapy (AIT) is an etiological treatment strategy that involves administering escalating doses of clinically relevant allergens to desensitize the immune system. It has shown encouraging results in reducing allergy symptoms and enhancing patients' quality of life. In this review, we offer a thorough overview of AIT in China, examining its efficacy, safety, current practices, and prospects. We further underscore the progress made in AIT research and clinical applications, as well as the distinct challenges and opportunities that China faces in this area.

Childhood blood eosinophils and symptoms of allergic disorders: a cross-sectional study in Southern China

PURPOSE

The relationship between childhood blood eosinophils and subtypes of allergic diseases remains understudied. This study aimed to examine the associations between childhood blood eosinophils and subtypes of asthma, rhinitis and dermatitis, as well as the modifying effect of age.

METHODS

We obtained concurrent blood cell counts and serum Immunoglobulin E (IgE) test results in 5026 children (0-13, years) from First Affiliated Hospital of Guangzhou Medical University from 2014 to 2019. Generalized additive models with multivariable adjustments were utilized to model the exposure-response relationship between eosinophils and allergic symptoms. The robustness of the association was assessed in two age categories (<6, 6-13 years).

RESULTS

The association of eosinophils with allergic asthma/rhinitis was positively nonlinear, with a plateau at levels of Q₄ (≥0.51, 10⁹/L). Conversely, exposure-response curves between eosinophils and the risk of non-allergic asthma and rhinitis were negatively linear, and especially, became statistically significant when levels of eosinophils were larger than Q₃ (≥0.30, 10⁹/L). Compared with their counterparts, school-aged children (6-13, years) with a higher level of blood eosinophils (≥0.35, 10⁹/L) were more likely to suffer from allergic asthma [relative excess risk due to interaction (RERI), 2.51; 95% CI, 1.24-3.78], allergic rhinitis (RERI, 2.79; 95% CI, 1.14-4.45) but not allergic dermatitis (RERI not significant).

CONCLUSION

Higher eosinophil counts were associated with the increased risk of allergic subtype symptoms and the decreased risk of non-allergic subtypes in children. Moreover, the associations between eosinophils and allergic asthma/rhinitis were accentuated in the school-aged child. These findings may contribute to providing novel insights for clinical administration relevance of allergic-related symptoms.Key messages:There was a positively nonlinear association between childhood eosinophils and allergic asthma/rhinitis.Age modified the associations between eosinophils and allergy-related outcomes. The associations of eosinophil with allergic asthma/rhinitis accentuated in the school-aged child (6-13, years).

Allergens sensitization among children with allergic diseases in Shanghai, China: age and sex difference

Background

The distribution of allergens has geographic characteristics. Local epidemiological data provides evidence-based strategies for the prevention and management of allergic diseases. Age and sex differences may exist in the prevalence of sensitivity to various allergens. We investigated the distribution of common allergens in allergic children in Shanghai, southeastern China.

Methods

39,926 children 1 month to 18 years of age diagnosed with allergic diseases were tested for the presence of serum-specific Immunoglobulins E (sIgE) to 17 allergens common to this region, using a reversed enzyme allergosorbent test.

Results

25,757 (64.5%) of the subjects showed elevated sIgE to at least one of the tested allergens. House mite and dust mite were the most common aeroallergens, while egg and milk were the most common food allergens. The most common aeroallergens and food allergens were similar among each allergic disease. By age-group analysis, the positive rates of aeroallergens were higher at older age. Several peaks of sensitization to food allergens were observed in children between 1 and 3 years of age for eggs, milk, nut, crab and shrimp. In addition, the sensitization to beef and mango was highest in children 3–6 years of age. The rate of positive sIgE detection was higher in males than females for all the tested allergens except cockroach, trees and beef. Considering the interplay between sex and ages and other related components (including season, monthly temperature, humidity, air quality index, test rate of patients), the sIgE positive rates of the main aeroallergens increased with age, while the main food allergens decreased; males are more sensitive to several aeroallergens (including dust mite, house mite, cat epithelium, dog epithelium and mulberry).

Conclusions

House mite, dust mite, milk, and egg are major allergens in Shanghai. Children at younger age are more sensitive to food allergens, while increasing overall prevalence of sensitization can be found with increasing age. Boys have higher positive rates of sIgE responses than girls. Knowledge of the prevalence of allergen sensitization in different age groups and sex may help facilitate diagnosis and intervention efforts to mitigate the impact of allergic diseases in this large geographical region. This approach may be extrapolated to other regions.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12931-022-02008-7.

Associations of Four sensitization patterns revealed by Latent Class Analysis with Clinical symptoms: A multi-center study of China

BACKGROUND

Because of the significant regional differences in the distribution of allergens, the relationship between anaphylaxis and allergic sensitization is complex in China. Using this large-scale epidemiologic survey, we explore the potential patterns of sensitization to common allergens in mainland China and investigate their relationship with various clinical symptoms.

METHOD

The participants were recruited from 13 medical centers in mainland China from October 2019 to June 2021. Skin prick test (SPT) results that cover 18 common allergens were utilized to diagnose atopic sensitization. The demographic characteristics and clinical information were collected through questionnaires during routine medical follow-up. Latent class analysis (LCA) was conducted to determine the optimal sensitization patterns. The logistic regression was used to assess the associations of different sensitization patterns with allergy symptoms.

FINDINGS

A total of 1089 patients who had a positive SPT to at least one of 18 allergens were included for formal analysis. An optimal LCA model with 4 classes was obtained in this study, and the corresponding labels were as follows: Class1, house dust mite sensitization; Class2, low pollen sensitization; Class3, middle pollen sensitization; Class4, high pollen sensitization. The prevalence of different classes varied widely in geographical distribution, which was characterized by Class1 being very common in south and east as well as Class2 in north and west of China. Compared with patients in Class1, those in middle and high pollen sensitization clusters had the higher odds ratios (ORs) of allergic rhinitis and allergic conjunctivitis when controlling for other confounders. However, there was no significant difference between low pollen sensitization and house dust mite sensitization groups in the risks for various clinical performances except dermatitis. Additionally, the adjusted ORs (95% confidence interval) of allergic conjunctivitis and dermatitis for participants in pollen sensitization clusters (Class2, 3 and 4) were 1.56 (1.18, 2.06) and 1.43 (1.09, 1.88) respectively compared with those in Class1.

INTERPRETATION

In this study, we identified four sensitization clusters with specific risks of various clinical symptoms using common allergens by adopting LCA. Our findings may contribute to improved diagnosis and potential immunotherapy approaches to allergy in mainland China.

FUNDING

This study was supported by the National Natural Science Foundation of China (81802076 and 81871736), the Guangzhou Science and Technology Foundation (202102010327), the Foundation of SKLRD (MS-2019-06 and Z-2022-09), and the Foundation of GYYY (ZH201904) and ZNSA-2020012.

Environmental and sensitization variations among asthma and/or rhinitis patients between 2008 and 2018 in China

Background

Little is known about the changes in allergen sensitization in China secondary to the environmental variations over the past decade. We aimed at investigating the variations in sensitization among asthma and/or rhinitis patients in China between 2008 and 2018.

Methods

This study analyzed cross‐sectional data from national surveys conducted in China in 2008 and 2018. After finishing the questionnaire, participants underwent serum specific IgE measurements. A total of 2322 and 2798 patients were enrolled in 2008 and 2018, respectively. The significance of differences in sensitization rates among four regions of China were assessed. Correlation analysis was used to identify the associations of sensitization with climate change and planting of Artemisia desertorum between the two surveys.

Results

Compared with 2008, the general sensitization rate to mites significantly increased in 2018, which ranked highest among all tested allergens. Sensitization to pollens, especially Artemisia vulgaris, showed the greatest increase in the north. The annual mean temperature, rainfall and relative humidity in all four regions, and the Artemisia desertorum coverage in the northeastern area, increased significantly in 2018 as compared with 2008. From 2008 to 2018, an increase in Dermatophagoides pteronyssinus sensitization was significantly associated with an increase in relative humidity (r = 0.54, p = 0.037). The increase in A. vulgaris sensitization was significantly associated with the increase in the A. desertorum planting area (r = 0.67, p = 0.006) and with a decrease in rainfall (r = −0.59, p = 0.021).

Conclusions

House dust mites remain the most important allergen in Chinese individuals with asthma and/or rhinitis. Pollen sensitization dramatically increased in northern China. Increases in sensitization to dust mites and Artemisia were related to the increases in humidity and planting area of A. desertorum.

Increase in Indoor Inhalant Allergen Sensitivity During the COVID-19 Pandemic in South China: A Cross-Sectional Study from 2017 to 2020

Purpose

Public health measures during COVID-19 have led to an unprecedented change in social lifestyle which might have an impact on the allergen sensitization in population. We sought to explore the prevalence patterns of serum inhalant and food allergen-specific IgE (sIgE) sensitization and serum total immunoglobulin E (tIgE) level among patients with clinical symptoms of suspected allergic diseases before and during the COVID-19 pandemic in south China.

Patients and Methods

A large epidemiology study was conducted on the prevalence patterns of sIgE sensitization and serum tIgE level among 13,715 patients with allergic symptoms in south China from 2017 to 2020. Chi-square test and Fisher exact test were used to test statistical significance of allergen sensitization difference among years. Logistic regression was performed to assess the magnitudes of the differences among years by adjusted odds ratios and 95% confidence intervals.

Results

The number of hospital visits for patients with suspected allergy symptoms decreased during COVID-19. The positive rates of indoor inhalant allergens (house dust mites, German cockroach, dog dander) and tIgE increased significantly in 2020, while no significant differences were found in food allergens (egg white, milk, soya bean, shrimp) before and during the COVID-19 pandemic. The odds of sIgE positives in indoor inhalant allergens and tIgE positive for 2017 and 2020 were all larger than 1.00. After grouping by age and gender, there were significant differences in the positive rates of indoor inhalant allergens and tIgE when comparing 2020 with 2017.

Conclusion

The prevalence of sensitization increased significantly to indoor inhalant allergens but not to food allergens in south China during the COVID-19 pandemic.

The Molecular Allergen Recognition Profile in China as Basis for Allergen-Specific Immunotherapy

Approximately 30% of the world population suffers from immunoglobulin-E (IgE)-mediated allergy. IgE-mediated allergy affects the respiratory tract, the skin and the gastrointestinal tract and may lead to life-threatening acute systemic manifestations such as anaphylactic shock. The symptoms of allergy are mediated by IgE-recognition of causative allergen molecules from different allergen sources. Today, molecular allergy diagnosis allows determining the disease-causing allergens to develop allergen-specific concepts for prevention and treatment of allergy. Allergen-specific preventive and therapeutic strategies include allergen avoidance, vaccination, and tolerance induction. The implementation of these preventive and therapeutic strategies requires a detailed knowledge of the relevant allergen molecules affecting a given population. China is the world´s most populous country with around 1.4 billion inhabitants and an estimated number of more than 400 million allergic patients. Research in allergy in China has dramatically increased in the last decade. We summarize in this review article what is known about the dominating allergen sources and allergen molecules in China and what further investigations could be performed to draw a molecular map of IgE sensitization for China as a basis for the implementation of systematic and rational allergen-specific preventive and therapeutic strategies to combat allergic diseases in this country.

Short-term exposure to ambient air pollution and hospital visits for IgE-mediated allergy: A time-stratified case-crossover study in southern China from 2012 to 2019

BACKGROUND

Because of the limited epidemiological evidence on the association between acute air pollutants and allergy, there is a need to investigate this association, especially between the short-term exposure to air pollution and the serum Immunoglobulin E (IgE)-mediated allergy.

METHODS

A total of 39,569 IgE test results and demographic characteristics were obtained in the First Affiliated Hospital of Guangzhou Medical University between August 2012 and September 2019. Ninety-nine specific allergens were tested according to clinical diagnosis. The logistic regression was used to assess the effects of CO, NO₂ and PM_2.5 exposure on the risk of sensitization to specific inhalant/food allergens. Generalized additive models with multivariate adjustments were utilized to model the exposure-response relationship. Stratified analyses were performed to estimate the reliability of correlations in various subgroups.

FINDINGS

Single-pollutant models indicate that the 3-day moving average (lag_2-4) of CO, PM_2.5 or NO₂ is associated with the increased risk for allergic diseases related to specific inhaled allergens. In multi-pollutant models, the adjusted Odds Ratio (OR) 95% (Confidence Interval, CI) increases by 8% (95% CI, 2%-15%) for per increment of 0.2 mg/m³ in CO levels, and rises by 8% (95% CI, 2%-13%) for each increase of 16.3 μg/m³ in PM_2.5 concentration. The associations are stronger in youngsters (<18, years) but not significantly different by gender. Particularly, a significantly stronger association between PM_2.5 exposure and hospital visits for inhaled allergy is observed in patients who are exposed to lower concentration of SO₂ (<10.333 μg/m³) and higher levels of NO₂ (≥42.0 μg/m³), as well as patients enrolled after 2017.

INTERPRETATION

The short-term exposure to CO/PM_2.5 increases the number of hospital visits for IgE-mediated allergy, especially for the sensitization to specific inhalant allergens. Therefore, to prevent inhaled allergies, the public policy for controlling air pollution needs to be considered seriously.

FUNDING

This study was supported by the University of Macau (grant numbers: FHS-CRDA-029-002-2017 and MYRG2018-00,071-FHS) as well as the Science and Technology Development Fund, Macau SAR (File no. 0004/2019/AFJ and 0011/2019/AKP). This work was also supported by the National Natural Science Foundation of China (81,871,736), the National Key Technology R&D Program (2018YFC1311902), the Guangdong Science and Technology Foundation (2019B030316028), the Guangzhou Municipal Health Foundation (20191A011073), and the Guangzhou Science and Technology Foundation (201,804,020,043).

CCD Inhibition Test Can Improve the Accuracy of the Detection of Pollen and Seed Food Allergen-Specific IgE in Southern China

Objective

The presence of cross-reactive carbohydrate determinants (CCDs) may cause false-positive results in vitro allergen sIgE tests. In this paper, we focused on pollen sensitisation and its relationship with CCD in patients with respiratory allergic diseases in South China. A CCD inhibition test was conducted to assess whether patients were truly allergic to pollen or whether their sIgE was caused by a CCD cross-reaction, thus providing an important basis for clinical diagnosis and treatment.

Methods

Patients with known serologic pollen sensitization were selected, and sIgE of mugwort, tree mix 20 (willow/poplar/elm tree), common ragweed, Humulus scandens, peanut, soybean and CCD was detected via the EUROBlotMaster system. Thirteen CCD-sIgE negative patients and 33 CCD-positive patients were selected, and their serum samples were subjected to the CCD inhibition test.

Results

We found that 66.0% to 95.9% of patients sensitised to pollen and seed food allergens were co-sensitized to CCD. Additionally, 73.0% to 100% of the sIgE tests for pollen and seed food allergens turned negative after inhibition, mostly for allergens from Humulus scandens (100%, 15/15), followed by mugwort and peanut (85.2%, 23/27), ragweed (81.5%, 22/27), soybean (80.0%, 20/25), and tree pollen (73.0%, 19/26).

Conclusion

CCD causes false positives in the in vitro allergen sIgE tests of patients with respiratory allergic diseases in South China. Attention should be paid to the use of CCD inhibitors in diagnosing in vitro allergies because of their importance in diagnosing and treating local allergic diseases.

Prevalence and screening of specific aeroallergens in Chinese male patients with chronic obstructive pulmonary disease: A retrospective cross-sectional observational study

INTRODUCTION

Sensitization to aeroallergens was linked to severe symptoms and frequent exacerbations in chronic obstructive pulmonary disease (COPD) patients. Elevated serum total immunoglobulin E (tIgE) level is a hallmark of allergic COPD patients. Phadiatop test exhibited high sensitivity for predicting specific aeroallergens (SAs) sensitization. However, the prevalence of aeroallergens, the value of Phadiatop test, alone or combined with tIgE, for predicting aeroallergens sensitization in male COPD patients have not been explored in China.

OBJECTIVES

To explore the prevalence and predictors of aeroallergens in the context of COPD.

METHODS

The predictive value of Phadiatop test for SAs sensitization in male COPD patients was analyzed via the area under receiver operating characteristic curves (AUCs).

RESULTS

The top five SAs in the context of COPD were d2, mx2, i6, d1, and tx5, of which the seasonal distribution showed no significant differences. Allergic group showed higher levels of blood eosinophils, total Phadiatop IgE and tIgE than the nonallergic group (all P ≤ 0.001). The AUCs of total Phadiatop IgE and tIgE for predicting the sensitization to SAs, SAs excluding mx2 (AEM) and mx2 were ((0.921 vs. 0.879, P = 0.2522), (0.967 vs. 0.807, P = 0.0003), and (0.780 vs. 0.883, P < 0.05)) (AUC_Phadiatop vs AUC_tIgE ), respectively. The combined application of these two parameters (model) increased the AUC of SAs, significantly higher than the single parameter used (P < 0.05 for all).

CONCLUSION

d2, mx2, i6, and d1 were the top four SAs sensitized in male COPD patients; Phadiatop test was valuable for predicting the sensitization to SAs when it was > 0.13 kAU/L.

The predominance of seafood allergy in Vietnamese adults: Results from the first population-based questionnaire survey

Background

Food allergy (FA) is a serious, costly and growing health problem worldwide. FA occurs in both children and adults; however, there is a paucity of information on FA prevalence and its clinical features in the adult population, especially in Asia. We sought to assess the prevalence of FAs in Vietnamese adults and the distribution of offending food items among different regions throughout Vietnam.

Methods

A nationwide, cross-sectional, population-based survey was conducted among University students aged 16–50 years. We used a structured, anonymous questionnaire, which was modified from recently published FA epidemiologic studies and based on European Academy of Allergy and Clinical Immunology (EAACI) guidelines, to collect data on FA prevalence, clinical presentations, and implicated food groups. Statistical analysis was performed to generate the prevalence of self-reported and doctor-diagnosed FA and to examine the association of key environmental factors and FA incidence in this population.

Results

Of the 14,500 surveys distributed, a total of 9,039 responses were returned, resulting in a response rate of 62.4%. Among participants who reported food-induced adverse reactions, 48.0% have repeated reactions. 18.0% of the participants perceived FA symptoms, but less than half of them sought medical services for confirmation (37.9%). Stratifying for true FA symptoms, the prevalence of self-reported FA was 11.8% and of doctor-diagnosed FA, 4.6%. The most common doctor-diagnosed FA was to crustacean (3.0%; 95% CI, 2.6–3.3), followed by fish (1.6%; 95% CI, 1.3–1.8), mollusk (1.3%; 95% CI, 1.0–1.5) and beef (1.0%; 95% CI, 0.8–1.2). The prevalence of doctor-diagnosed FA differed among participants living in urban (6.5%) and rural regions (4.9%) (P < 0.001). Atopic family history was the strongest predictor for FA (odds ratio 8.0; 95% CI, 6.2–10.4).

Conclusions

Seafood allergy among adults is predominant in Vietnam, followed by beef, milk, and egg, while peanut, soy, and tree nut allergy are much less common. Populations in rural regions have considerably less FA; however, the protective environmental factors have yet to be identified.

Allergen sensitization pattern of allergic adults and children in southern China: a survey based on real life data

Background

Allergic diseases are increasing yearly. We aimed to evaluate the difference in allergen sensitization pattern between adults and children in southern China by analyzing a large sample size of real-life data, and to provide the evidence for formulating the prevention and management strategies.

Methods

Retrospective analysis was conducted on 39,813 serum allergen-specific IgE (sIgE) results collected in southern China from January to December in 2017. Sensitization patterns and how these allergens could lead to the allergic diseases were analyzed for adults and children respectively. The difference of allergen positive rate between groups was calculated using the Chi square test.

Results

The top five most sensitized allergens in southern China were house dust mite (28.1%), cockroach (24.3%), shrimp (19.2%), crab (15.5%) and egg white (9.9%). While cockroach had the highest positive rate in adults (29.2%), the most sensitized allergen in children was house dust mite (29.7%). The positive rates of egg white and cow’s milk in children were higher than in adults for the whole year (p < 0.001); whereas for adults, the positive rate to cockroach, shrimp and crab were higher than in children (p < 0.001). The positive rate of house dust mite in coastal cities (32.4%) was higher than that in landlocked cities (24.0%) in children, but in adults, the rate in landlocked cities (31.1%) was higher than that in coastal cities (25.3%). Optimal scaling analysis showed that the sIgEs of crab and shrimp had the closest correlation with cockroach-sIgE (Cronbach’s α = 0.891). The positive rate to mold allergens increased from summer to autumn, reaching its plateau in October (6.2%). Patients with skin diseases were found to receive the highest sIgE prescription from doctors (56.9%).

Conclusions

Doctors tend to prescribe more sIgE tests for patients with skin disorders in southern China. In addition to house dust mite, cockroach was found to be another important allergen. Adults with multiple sensitization always showed co-sensitization with shrimp, crab and house dust mite. These should be taken into consideration when giving allergen avoidance advice to patients.

Electronic supplementary material

The online version of this article (10.1186/s13223-019-0357-y) contains supplementary material, which is available to authorized users.

Allergy and related clinical symptoms among medical students and interns

OBJECTIVES

To determine the prevalence, types, clinical presentations, triggers, and predictors of allergic disorders among medical students and interns at King Abdulaziz University (KAU), Jeddah, Saudi Arabia.

METHODS

A cross-sectional design was used for this study in which 600 medical students and interns were selected by a multistage stratified random sampling. A validated, confidential, self-administered questionnaire was used during 2016 / 2017. It asked about the previous diagnosis of allergic disorders, associated factors, types, clinical symptoms and the triggering allergenic. Descriptive & inferential statistics were done and logistic regression analysis was conducted.

RESULTS

The overall prevalence of diagnosed allergic disorder(s) among the participants was 36.2%.The commonest types of allergy were skin (33.8%) followed by respiratory (29.5%) presentations. The most frequently reported allergenic triggers were the house dust (45.6%) and smoke (30.4%). The first allergy predictor was family history of allergic disorders (aOR= 4.35, 95 % CI: 2.96-6.39), followed by female gender. Regarding the outcome of allergy on students' life, 16.1% occasionally missed classes, and 28.6% had sleep disturbance during allergic attacks.

CONCLUSION

Allergy represents an important problem among medical students and interns. Family history and female gender were the predictors of allergy. Skin and respiratory allergies were the most common types. House dust and smoke were the commonest allergenic triggers. Detection of allergens and management of cases of allergy among medical students and interns are needed. Education and conduction of awareness campaigns about allergy are needed.