Prevalence of food-allergen and aeroallergen sensitization among people in Sichuan, Western China: An 8-year observational study

Food-Pollen Cross-Reactivity and its Molecular Diagnosis in China

PURPOSE OF REVIEW

Plant-derived foods are one of the most common causative sources of food allergy in China, with a significant relationship to pollinosis. This review aims to provide a comprehensive overview of this food-pollen allergy syndrome and its molecular allergen diagnosis to better understand the cross-reactive basis.

RECENT FINDINGS

Food-pollen cross-reactivity has been mainly reported in Northern China, Artemisia pollen is the major related inhalant source, followed by tree pollen (Betula), while grass pollen plays a minor role. Pollen allergy is relatively low in Southern China, with allergies to grass pollen being more important than weed and tree pollens. Rosaceae fruits and legume seeds stand out as major related allergenic foods. Non-specific lipid transfer protein (nsLTP) has been found to be the most clinically relevant cross-reacting allergenic component, able to induce severe reactions. PR-10, profilin, defensin, chitinase, and gibberellin-regulated proteins are other important cross-reactive allergen molecules. Artemisia pollen can induce allergenic cross-reactions with a wide range of plant-derived foods in China, and spring tree pollens (Betula) are also important. nsLTP found in both pollen and plant-derived food is considered the most significant allergen in food pollen cross-reactivity. Component-resolved diagnosis with potential allergenic proteins is recommended to improve diagnostic accuracy and predict the potential risk of causing allergic symptoms.

Patterns of aeroallergen sensitization in asthma patients identified by latent class analysis: A cross-sectional study in China

BACKGROUND

This cross-sectional study aimed to identify latent sensitization profiles of asthma patients in mainland China, unveiling the association between regional differences and sensitization patterns.

METHODS

1056 asthma participants from 10 medical centers divided into eastern and western cohorts were clustered into four individual sensitization patterns, respectively, by using an unsupervised statistical modeling method, latent class analysis (LCA), based on the levels of 12 aeroallergens specific IgE reactivities. Moreover, differences in clinical characteristics and environmental exposures were compared in different sensitization patterns.

RESULTS

Four distinct sensitization patterns in the two cohorts were defined as follows, respectively. Eastern cohort: Class 1: "High weed pollen and house dust mites (HDMs) sensitization" (8.87%), Class 2: "HDMs dominated sensitization" (38.38%), Class 3: "High HDMs and animal dander sensitization" (6.95%), Class 4: "Low/no aeroallergen sensitization" (45.80%). Western cohort: Class 1: "High weed pollen sensitization" (26.14%), Class 2: "High multi-pollen sensitization" (15.02%), Class 3: "HDMs-dominated sensitization" (10.33%), Class 4: "Low/no aeroallergen sensitization" (48.51%). Of note, the significant statistical difference in age, asthma control test score (ACT) and comorbidities were observed within or between different sensitization patterns. Exposure factors in different sensitization patterns were pointed out.

CONCLUSIONS

Asthmatic patients with distinct sensitization patterns were clustered and identified through the LCA method, disclosing the relationship between sensitization profiles of multiple aeroallergens and geographical differences, providing novel insights and potential strategies for atopic disease monitoring, management and prevention in clinical practice.

Allergen Sensitization in Patients with Skin Diseases in Shanghai, China

Introduction

Allergen distribution has obvious geographical characteristics. Understanding local epidemiological data may provide evidence-based strategies for the prevention and management of disease. We investigated the distribution of allergen sensitization in patients with skin diseases in Shanghai, China.

Methods

Data from tests for serum-specific immunoglobulin E were collected from 714 patients with three skin diseases who visited the Shanghai Skin Disease Hospital from January 2020 to February 2022. The prevalence of 16 allergen species, as well as age, sex, and disease-group differences in allergen sensitization, were investigated.

Results

Dermatophagoides farinae and Dermatophagoides pteronyssinus were the most common aeroallergen species to cause allergic sensitization in patients with skin diseases, whereas shrimp and crab were the most common food-allergen species. Children were more susceptible to various allergen species. With regard to sex differences, males were sensitized to more allergen species than females. Patients suffering from atopic dermatitis were sensitized to more allergenic species than patients with non-atopic eczema or urticaria.

Conclusion

Allergen sensitization in patients with skin diseases in Shanghai differed by age, sex, and disease type. Knowing the prevalence of allergen sensitization across age, sex, and disease type may help facilitate diagnostic and intervention efforts, and guide the treatment and management of skin diseases in Shanghai.

Sensitization to Furry Animals in Patients with Suspected Allergic Disease in China: A Multicenter Study

PURPOSE

An objective of this study was to investigate the allergen sensitization characteristics of cat, dog and horse dander in patients with suspected allergic diseases in different geographical regions of Chinese mainland.

PATIENTS AND METHODS

We invited 2377 patients aged 0-86 years with suspected allergic diseases to participate in a cross-sectional survey in 11 provinces in China. Combined with the questionnaires and animal-specific IgE levels, we analyzed the epidemiological characteristics and risk factors of furry animal sensitization in different regions and populations of Chinese Mainland.

RESULTS

Among the 2377 patients with suspected allergic diseases, 14.9% were sensitized to cat dander, 9.3% to dog dander and 5.5% to horse dander. Animal allergens mainly cause low-level sensitization (class 1-3). There was a significant correlation between cat, dog and horse dander allergen sIgE, with correlation coefficients (rs) all greater than 0.750. The majority (46.5%) of sIgE-positive patients were sensitized to at least two animal allergens simultaneously. The prevalence of these animals all showed a trend of increasing first and then decreasing with age, and all reached the peak in young adolescence. As for the geographical factors, the sensitization rate of cats and dogs in Western was significantly higher than that in Eastern (cat: 18.4% vs 9.2%, dog: 11.6% vs 5.5%, all P < 0.001), however, no significant differences were found in horses. Aged ≤6 years, living in Western, and high animal allergen exposure elevated the risk of cat or dog sensitization. Living on a lower floor (aOR: 0.56) was a protective factor for horse sensitization.

CONCLUSION

In this representative sample of Chinese patients with suspected allergic diseases, there was an apparent geographic variation in sensitization to cats and dogs. Age factor and living in Western also had a significant impact on animal allergen sensitization rate.

Chinese Central Compartment Atopic Disease: The Clinical Characteristics and Cellular Endotypes Based on Whole-Slide Imaging

Purpose

Histopathologic characterizations of central compartment atopic disease (CCAD) by whole-slide imaging remains lacking. We aim to study clinical presentations and cellular endotyping diagnosis of Chinese CCAD using artificial intelligence (AI).

Methods

A total of 72 patients diagnosed with chronic rhinosinusitis with nasal polyps (CRSwNP) were enrolled. CCAD was defined by positive result of serology specific IgE, endoscopic and radiological findings. The aeroallergen sensitization status, endoscopic results, radiological findings, and symptoms were evaluated and compared between patients with CCAD (n=14), eosinophilic CRSwNP (ENP, n=32) and non-eosinophilic CRSwNP (NENP, n=26). The cellular endotypes including eosinophils, neutrophils, lymphocytes, and plasma cells were analyzed by the AI chronic rhinosinusitis evaluation platform 2.0.

Results

CCAD was most common in male (71.43%). The positive rate of aeroallergen in patients with CCAD is 100%, which is much higher than those in patients with ENP (40.63%) and NENP (23.08%). Allergic rhinitis incidence was found to be 57.14% in Chinese CCAD subjects, which is obviously higher when compared with those in patients with ENP (21.88%) or NENP (0.00%). The presence of asthma was not significantly different between groups. Chinese CCAD population demonstrated mild symptoms and lower endoscopic and radiological scores than those in patients with ENP and NENP. For cellular endotypes in CCAD subjects, the median of eosinophils, neutrophils, lymphocytes, and plasma cells was 26.55%, 0.49%, 60.85%, and 7.33%, respectively. The proportion of eosinophils in nasal tissue and peripheral blood mononuclear cells from the CCAD group is between the proportions in those patients with ENP and NENP.

Conclusion

Chinese CCAD was associated with aeroallergen sensitivity, and displayed an eosinophil-dominant inflammatory pattern. Thus, proper management with allergy control and topical steroids could be recommended for CCAD treatment.

[Allergen Analysis of 4622 Children with Allergic Diseases in Shaanxi Province]

OBJECTIVE

To study the distributional characteristics of allergens in children with allergic diseases in Shaanxi province.

METHODS

A total of 4 622 children diagnosed with allergic diseases in the Asthma Center, Department of Pediatrics, Xijing Hospital from March 2015 to February 2019 were selected. Serum allergen-specific immunoglobulin E (sIgE) of 19 common kinds of allergens were examined with enzyme-linked immunosorbent assay (ELISA). The children were divided into different groups according to sex, age and geographical regions, and the distributional characteristics of allergens of the different groups were compared.

RESULTS

The overall positive rate for the 19 allergens of the 4 622 children was 62.8%. The ranking of the positive rates for individual allergens from high to low were as follows: 24.2% for milk, 18.0% for mold mix, 16.7% for dog dander, 16.4% for house dust mite, 11.7% for cat dander, 10.7% for cashew, 10.6% for weed pollen, 8.8% for egg white, 7.8% for house dust, 7.7% for tree pollen, 5.6% for amaranth, 4.9% for mulberry tree, 3.6% for mango, 3.2% for beef, 2.8% for cockroach, 2.1% for crab, 1.5% for shrimp, 0.8% for pineapple, and 0.3% for shellfish. Analysis based on sex showed that the allergen positive rates in boys were higher than those in girls. Analysis by age difference showed that generally the positive rates for inhaled allergens increased along with the increase in patient age, while the positive rates for ingested allergens decreased along with the increase in patient age. Analysis by geographical regions showed that the positive rate of house dust mite in the patients from the southern part of Shaanxi, the positive rate of weed pollen in the patients from the northern part of Shaanxi and the positive rates of milk and egg white in the patients from the central part of Shaanxi were higher than those in other areas. The cluster analysis and correlation analysis showed that the 19 allergens could be roughly divided into 4 categories. There were moderate correlations among tree pollen, mulberry tree and amaranth. There were moderate correlations among mulberry tree, mango and amaranth. There was moderate correlation between shrimp and crab, and there were mild or weak correlations among most of the other allergens.

CONCLUSION

Among the 4 622 children with allergic diseases in Shaanxi Province who were treated in the Asthma Center, Department of Pediatrics, Xijing Hospital, male patients showed higher sensitivity to allergens. The positive rates of inhaled allergens increased, while the positive rates of ingested allergens decreased with increase in patient age. There were regional differences in the distribution of allergens. Some allergens were correlated with each other, which may be related to cross-reaction.

Prevalence of allergen-specific IgE in southern China: a multicenter research

Identifying allergen distribution is meaningful and significant for effective diagnosis and treatment of allergic diseases. This study compared the allergen sensitivity in four southern China cities. We enrolled 55,432 participants (27,408 male, 28,024 female) between 2007 and 2019. The allergen-specific IgE levels were compared by the χ2 test. The five prevalent sensitivities were for mite mix (10,985, 19.82%), cockroach (4,860, 8.77%), crab (4,450, 8.03%), fish mix (3,874, 6.99%), and house dust (3,486, 6.29%). Almost all allergen sensitivities decreased with age, particularly from infant to middle aged participants (p < 0.05). An exception was Shenzhen, where food allergen positive rates remained constant in all age groups studied. The proportion of male sensitive to at least one food allergen (OR 1.130; 95% CI 1.088–1.174, p < 0.0025) or aeroallergen (OR, 1.117; 95% CI, 1.078–1.158, p < 0.0025) was higher than female in all four cities. Except for dog dander and tree mix, all aeroallergens differed significantly between seasons (p < 0.05). Liuzhou had the highest rates of food allergen- and aeroallergen-positive participants. The allergen-specific IgE distribution differed among the studied cities, with significant seasonal differences. Young age, male sex, and aeroallergens were risk factors for allergic disease.

China Consensus Document on Allergy Diagnostics

The prevalence of allergic diseases has increased dramatically in recent years in China, affecting the quality of life in 40% of the population. The identification of allergens is the key to the diagnosis of allergic diseases. Presently, several methods of allergy diagnostics are available in China, but they have not been standardized. Additionally, cross-sensitization and co-sensitization make allergy diagnostics even more complicated. Based on 4 aspects of allergic disease (mechanism, diagnosis procedures, allergen detection in vivo and in vitro as well as the distribution map of the most important airborne allergens in China) and by referring to the consensus of the European Society of Allergy and Clinical Immunology, the World Allergy Organization, and the important literature on allergy diagnostics in China in recent years, we drafted this consensus of allergy diagnostics with Chinese characteristics. It aims to standardize the diagnostic methods of allergens and provides a reference for health care givers. The current document was prepared by a panel of experts from the main stream of professional allergy associations in China.

Prevalence of food-allergen and aeroallergen sensitization among people in Sichuan, Western China: An 8-year observational study

BACKGROUND

Identifying the distribution of allergens is invaluable to effective diagnosis and treatment of allergic disease. The present study aims to analyze the epidemiology of allergens in Sichuan, Western China.

METHODS

A total of 14 030 participants including 8031 men and 5999 women were enrolled in this study during 2007-2014 in West China Hospital. An assay testing for the presence of allergen-specific IgE was used to identify highly immunogenic allergens.

RESULTS

Of the 14 030 total participants, 3470 (24.72%) were sensitive to at least one of tested allergens. The most immunogenic allergens were mite mix (1876, 13.38%), crab (876, 6.24%), sea-fish mix (865, 6.16%), house dust (355, 2.54%), and cockroach (292, 2.08%). The differences between population of participants who were sensitive to food allergens and aeroallergens were statistically significant in 0 to 10, 11 to 20, 21 to 30, 41 to 50, and 51 to 60 year-old age-groups (all P < 0.05). Distributions of three food allergens and two aeroallergens were significantly different between male and female participants. There was also an increase in sensitization to cow's milk, mutton, sea-fish, and mould that was observed in the 71 to 90 year-old group.

CONCLUSION

The most common allergens presented in Sichuan were observed to be mites, crab, sea-fish, and house dust. There was an observable difference in sensitivity to five allergens between males and females. Additionally, aeroallergens appeared to have a greater immunogenic effect in younger populations while the elderly presented with increased sensitization to specific allergens, suggesting that specific allergens' immunogenicity was age-dependent.