Frontiers in Allergy presents this article collection that spotlights the work and achievements of researchers based in Asia. The goal of this special edition Research Topic is to highlight the progress made in Asia, with the aim to inform and inspire researchers from this region and globally. Submissions from authors located in Asia focusing on new insights, novel developments, current challenges, latest discoveries, recent advances and future perspectives will be welcomed.

James Cook University

College of Medicine, Yonsei University

Frontiers in Allergy

Asthma

Drug, Venom & Anaphylaxis

Environmental & Occupational Determinants

Food Allergy

Rhinology

Skin Allergy

Allergens

Allergen Immunotherapy

Infections and Microbiome

Allergy Diagnosis

Mechanisms in Allergy

Therapies and Therapeutic Targets

Spotlight on Allergy Research in Asia

Editorial on the Research Topic <a href="https://www.frontiersin.org/research-topics/48417/spotlight-on-allergy-research-in-asia">Spotlight on allergy research in Asia</a>A lot of studies on allergic diseases are being conducted and great progress has been made in Asia. Notably, advanced technologies such as genomics, transcriptomics, proteomics, and bioinformatics have enabled researchers to investigate the immunological responses to the environments and biochemical characteristics of allergen sources. The goal of this Research Topic was to highlight the progress made in Asia and inspire researchers. However, we were not able to cover all aspects. More insights on the allergens of regional importance in Asia can be gained from recent collections with similar subjects (<a href="#B1">1</a>–<a href="#B4">4</a>).In the current Research Topic, we summarized some aspects of microbiome study, allergen sensitization patterns, and immunotherapy in Asia. The house dust mite (HDM) microbiome study describes the origin of endotoxins in the mite extracts (<a href="https://doi.org/10.3389/falgy.2023.1240727">Yi et al.</a>). It provided potential insight into controlling endotoxins in the mite extracts. Characteristics of the allergenic molecule itself are important for the induction of allergic responses. However, the allergen matrix effect is also important for the allergenicity of allergenic proteins since allergens are not the only molecules introduced to the immune system. Therefore, molecular patterns derived from allergen sources need to be investigated in more detail.HDMs and pollens are the most important causes of respiratory allergy in Asia. Oak, mugwort, ragweed, and Japanese hop are the most common causes of pollinosis in Korea. Mugwort in China and Japanese cedar in Japan are the most potent causes of pollinosis. In particular, three dust mite species (D. farinae, 59.8%; D. pteronyssinus, 50.4%; and Blomia tropicalis, 49.6%) seem to be prevalent sensitizers in Vietnam (<a href="https://doi.org/10.3389/falgy.2022.1058865">Trinh et al.</a>). Interestingly, Blomia-sensitized patients were older, and Dermatophagoides-sensitized patients were younger than non-sensitized groups. More in-depth studies are needed on the sensitization patterns to dust mite allergens. More studies are needed on the cockroach species and termites. Cockroach sensitization was investigated using German cockroaches but Oriental cockroaches are also found in Vietnam and other Asian countries. No information is available on termite species. Studies on the allergens from wheat, buckwheat, and soybean are being performed in Asia. Most food allergies (grain and fish) affect children and outgrow. However, wheat allergy and buckwheat allergy are common in adults. The allergenicity of traditional fruits in Asia is of interest. For example, Korean melon often causes pollen food allergy syndrome (PFAS) in Korea but no allergen has been identified yet. Many tropical fruits such as Jackfruit, avocado, lychee, papaya, passionfruit, guava, and mango, are commonly consumed in South Asia including Vietnam, Thailand, and the Philippines. However, the allergenicity of these fruits in Asia and their molecular characteristics are not well defined (<a href="#B5">5</a>). PR-10 is thought to be mainly responsible for PFAS to tropical fruits. Studies on Asian vegetable allergy are also limited. For example, allergy to cilantro (coriander) is rare but commonly consumed in Asia.Standardization of allergen extracts is inevitable for accurate allergy diagnosis and production of effective immunotherapeutics (<a href="#B6">6</a>). Most of the reagents for the immunotherapy are imported from Western countries. The HDM is the first choice for local manufacturing in Asia. National reference materials were produced in Japan, Korea, China, and Thailand. Various reference materials supported by the government were produced in Korea, yet HDM extract is the only standardized extract that is commercially available (<a href="#B7">7</a>). Japanese cedar in Japan and mugwort in China, which are allergen sources of regional importance, are the second choice for standardization.We also can get some insight from a study from South Vietnam on the sensitization profile (<a href="https://doi.org/10.3389/falgy.2022.1058865">Trinh et al.</a>). The southern part of Vietnam is tropical and does not suffer from seasonal pollinosis. Sensitization patterns on pollen allergens are missing due to the lack of allergen extracts from indigenous plant species. In some cases, standardized pollen allergen extracts are not imported and the in-house preparations for skin tests are used. This implies the urgent necessity of collaboration with the manufacturers with GMP facilities and experienced researchers.<a href="https://doi.org/10.3389/falgy.2023.1324844">Yang et al.</a> described some different situations of allergen immunotherapy in China partly due to the regulations of the Chinese government. It is necessary to localize more commercial products reflecting regional needs.Not only differences in fauna and flora but also cultural differences between Western and oriental countries influence the allergen sensitization pattern. Food preferences and preparations are different among countries reflecting the cultural differences. The allergenicity of the foods depends on the cooking method. More studies are necessary on these aspects. <a href="https://doi.org/10.3389/falgy.2021.618713">Masumi et al.</a> described the Japanese attitude toward reintroduction following an oral food challenge (OFC). This study provides insight into long-term outcomes after negative OFC. Eggs are not re-introduced into the children's diet largely due to the caregiver's anxiety, indicating the necessity of dietary guidance after OFC.In-depth studies and progress on allergy research are being made in Asia. However, more interest should be given to differences from Western countries such as flora, fauna, culture, culinary preferences, and regulations. Especially, Asian fruit and vegetable allergens are of interest, and various allergens from foods indigenous to Asian countries are waiting for molecular characterization.KJ: Writing &#x2013; original draft. AL: Writing &#x2013; review &amp; editing.Thanks to all contributors and reviewers for their efforts and patience to this Research Topic.The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.

Editorial: Spotlight on allergy research in Asia

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.

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&apos; 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.

Allergen immunotherapy in China

Understanding the house dust mites (HDMs) microbiome is crucial due to its potential effects on the development of allergic diseases. In 1998, our laboratory collected Dermatophagoides farinae and D. pteronyssinus from beds in a Korean household and began cultivating these HDMs. Our laboratory has been actively investigating several topics about HDMs in recent years, including the bacterial and fungal microbiome and their interactions, as well as the impact of the HDM microbiome on airway inflammation. To study the D. farinae microbiome, we employed high-throughput sequencing of the 16S rDNA amplicons. The results revealed that the two most abundant bacteria were Enterococcus faecalis and Bartonella spp. In contrast, we found almost no bacteria in D. pteronyssinus. By inoculating bacteria to HDMs, we found that D. farinae is more susceptible to bacteria than D. pteronyssinus. This susceptibility was associated with the presence of certain fungal species in D. pteronyssinus. Additionally, we have recently made efforts to produce HDMs with reduced levels of symbiotic bacteria. We believe that standardizing and controlling the microbiome in HDMs are crucial steps for the future development and improvement of allergic immunotherapies.

Understanding the house dust mites (HDMs) microbiome is crucial due to its potential effects on the development of allergic diseases. In 1998, our laboratory collected Dermatophagoides farinae and D. pteronyssinus from beds in a Korean household and began cultivating these HDMs. Our laboratory has been actively investigating several topics about HDMs in recent years, including the bacterial and fungal microbiome and their interactions, as well as the impact of the HDM microbiome on airway inflammation. To study the D. farinae microbiome, we employed high-throughput sequencing of the 16S rDNA amplicons. The results revealed that the two most abundant bacteria were Enterococcus faecalis and Bartonella spp. In contrast, we found almost no bacteria in D. pteronyssinus. By inoculating bacteria to HDMs, we found that D. farinae is more susceptible to bacteria than D. pteronyssinus. This susceptibility was associated with the presence of certain fungal species in D. pteronyssinus. Additionally, we have recently made efforts to produce HDMs with reduced levels of symbiotic bacteria. We believe that standardizing and controlling the microbiome in HDMs are crucial steps for the future development and improvement of allergic immunotherapies.

Investigating the microbiome of house dust mites in South Korea

BackgroundClimatic and geographical characteristics may alter the plant distribution and thereby the patterns of allergens.</sec>ObjectiveTo evaluate the profile of allergen sensitization in patients in southern Vietnam and its association with allergic diseases.</sec>MethodsWe collected data of 423 patients who visited the Unit of Allergy and Clinical Immunology, University Medical Center, Vietnam from 2014 to 2021, from their medical records. Patients underwent skin prick tests to the 12 most common aeroallergens. Clinical evaluation and diagnosis of allergic diseases was done in consert with their allergen sensitization status.</sec>ResultsMites and cockroach were the most prevalent sensitizing allergens, with the sensitization prevalences as followed: Dermatophagoides farinae (Df) (59.8%), Dermatophagoides pteronyssinus (Dp) (50.4%), Blomica tropicalis (Bt) (49.6%), storage mites mix (10.4%), and cockroach (10.2%). Sensitization to Df was more predominant in males than in females (66% vs 54.1%). Dp-sensitized patients were younger than non-sensitized patients (29.01 ± 13.60 vs. 32.17 ± 14.89) whereas storage mites-sensitized patients were older than the non-sensitized groups (36.25 ± 13.53 vs. 28.76 ± 13.39) (p < 0.05 for all). A considerable proportion of patients with urticaria, allergic rhinitis, and atopic dermatitis were sensitized to mites. Polysensitization to different species of house dust mites (Dp, Df) and storage mites (Bt) was prevalent among patients sensitized to any kind of mites.</sec>ConclusionsAmong people living in southern Vietnam, HDM mites, and cockroach were the predominant allergens. Further studies on the factors regulating the association between allergen sensitization with allergic diseases and polysensitization are crucial.</sec>

Background: Climatic and geographical characteristics may alter the plant distribution and thereby the patterns of allergens.Objective: To evaluate the profile of allergen sensitization in patients in southern Vietnam and its association with allergic diseases.Methods: We collected data of 423 patients who visited the Unit of Allergy and Clinical Immunology, University Medical Center, Vietnam from 2014 to 2021, from their medical records. Patients underwent skin prick tests to the 12 most common aeroallergens. Clinical evaluation and diagnosis of allergic diseases was done in consert with their allergen sensitization status.Results: Mites and cockroach were the most prevalent sensitizing allergens, with the sensitization prevalences as followed: Dermatophagoides farinae (Df) (59.8%), Dermatophagoides pteronyssinus (Dp) (50.4%), Blomica tropicalis (Bt) (49.6%), storage mites mix (10.4%), and cockroach (10.2%). Sensitization to Df was more predominant in males than in females (66% vs 54.1%). Dp-sensitized patients were younger than non-sensitized patients (29.01 ± 13.60 vs. 32.17 ± 14.89) whereas storage mites-sensitized patients were older than the non-sensitized groups (36.25 ± 13.53 vs. 28.76 ± 13.39) (p &lt; 0.05 for all). A considerable proportion of patients with urticaria, allergic rhinitis, and atopic dermatitis were sensitized to mites. Polysensitization to different species of house dust mites (Dp, Df) and storage mites (Bt) was prevalent among patients sensitized to any kind of mites.Conclusions: Among people living in southern Vietnam, HDM mites, and cockroach were the predominant allergens. Further studies on the factors regulating the association between allergen sensitization with allergic diseases and polysensitization are crucial.

Profile of aeroallergen sensitizations in allergic patients living in southern Vietnam

Background: Oral food challenge (OFC) is the most reliable method for diagnosing food allergies. However, the scarcity of long-term data on eating habits of people after a negative OFC poses a challenge for provisional medical care.Objective: This study was performed to investigate the percentage of people who could reintroduce eggs into their diet several years after an OFC.Methods: Study participants included 0–6-year-old children with negative results from an OFC using one egg as the food allergen, boiled for 20 min, from January 2012–March 2017, 1–3 years after the OFC.Results: A total of 72 subjects were analyzed, out of which 52 were males (72.2%). The median age (range) was 20 months (16–32.3), and the median age (range) at the first OFC was 15 months (12.8–23.3). Eggs were reintroduced in 62 cases (86.1%), while 10 cases (13.9%) did not undergo any diet change. The adjusted odds ratio (OR, 95% CI), with post-OFC to pre-OFC anxiety ≥ 0.2, was 9.4 (1.0–86), p = 0.04; OR for allergic symptoms that occurred post-OFC was 2.2 (0.45–11), p = 0.34; OR for initial OFC at an age of ≥15 months was 3.2 (0.54–19), p = 0.2; and OR for the history of anaphylaxis from eggs was 0.17 (0.02–1.5), p = 0.11.Conclusion: Most cases reintroduced eggs after an OFC. However, reintroduction did not occur in some cases, which was associated with greater anxiety among caregivers post-OFC. If the caregiver's anxiety is intense, it is necessary to provide psychological intervention and dietary guidance when reintroducing eggs at home after an OFC and to follow-up outpatient long-term progress.

Background: Oral food challenge (OFC) is the most reliable method for diagnosing food allergies. However, the scarcity of long-term data on eating habits of people after a negative OFC poses a challenge for provisional medical care.Objective: This study was performed to investigate the percentage of people who could reintroduce eggs into their diet several years after an OFC.Methods: Study participants included 0–6-year-old children with negative results from an OFC using one egg as the food allergen, boiled for 20 min, from January 2012–March 2017, 1–3 years after the OFC.Results: A total of 72 subjects were analyzed, out of which 52 were males (72.2%). The median age (range) was 20 months (16–32.3), and the median age (range) at the first OFC was 15 months (12.8–23.3). Eggs were reintroduced in 62 cases (86.1%), while 10 cases (13.9%) did not undergo any diet change. The adjusted odds ratio (OR, 95% CI), with post-OFC to pre-OFC anxiety ≥ 0.2, was 9.4 (1.0–86), p = 0.04; OR for allergic symptoms that occurred post-OFC was 2.2 (0.45–11), p = 0.34; OR for initial OFC at an age of ≥15 months was 3.2 (0.54–19), p = 0.2; and OR for the history of anaphylaxis from eggs was 0.17 (0.02–1.5), p = 0.11.Conclusion: Most cases reintroduced eggs after an OFC. However, reintroduction did not occur in some cases, which was associated with greater anxiety among caregivers post-OFC. If the caregiver's anxiety is intense, it is necessary to provide psychological intervention and dietary guidance when reintroducing eggs at home after an OFC and to follow-up outpatient long-term progress.