Perspectives and gaps in the management of food allergy and anaphylaxis in the Asia-Pacific Region

Background

Food allergy (FA), which is a condition that has no effective cure and can result in severe life-threatening allergic reactions, remains a global public health concern; however, little is known about how FAs are currently managed in the Asia-Pacific region.

Objective

The main objective of this survey was to evaluate the epidemiology of FA, as well as the availability of resources and practices for management of FA and anaphylaxis by health care providers across Asia.

Methods

From June 2022 to September 2022, a questionnaire-based survey comprising 66 questions was electronically sent to member societies of the Asia Pacific Association of Allergy Asthma and Clinical Immunology by using Survey Monkey.

Results

A total of 20 responses were received from 15 member countries and territories. Compared with the pediatric data, there was a lack of prevalence data for FA in adults. Except for Australia and Japan, most regions had between 0.1 and 0.5 allergists per 100,000 population and some had fewer than 0.1 allergists per 100,000 population. The perceived rate of FA in regions with a short supply of allergists was high. Although specific IgE tests and oral food challenges were available in all regions, the median wait time for oral food challenges at government facilities was 37 days (interquartile range = 10.5-60 days). Seven regions still relied on prescriptions of ampules and syringes of injectable adrenaline, and adrenaline autoinjectors were not accessible in 4 regions. Oral immunotherapy as FA treatment was available in half of the surveyed countries and territories.

Conclusions

Our study offers a cross-sectional evaluation of the management practices for FA in each Asia Pacific Association of Allergy Asthma and Clinical Immunology member country or territory. Urgent actions are required to enhance allergy services, improve the accessibility and affordability of adrenaline autoinjectors, and conduct robust epidemiologic studies.

Disparities in pediatric anaphylaxis triggers and management across Asia

BACKGROUND

The epidemiology and management of anaphylaxis are not well-reported in Asia.

METHODS

A regional pediatric anaphylaxis registry was established by the Asia-Pacific Research Network for Anaphylaxis (APRA), using standardized protocols for prospective data collection, to evaluate the triggers and management of anaphylaxis in the Asia-Pacific region. Pediatric patients below 18 years presenting with anaphylaxis across four Asian countries/cities (Thailand, Singapore, Hong Kong (HK), and Qingdao) were included. Allergen triggers, symptoms, anaphylaxis severity, and management were compared.

RESULTS

Between 2019 and 2022, 721 anaphylaxis episodes in 689 patients from 16 centers were identified. The mean age at anaphylaxis presentation was 7.0 years (SD = 5.2) and 60% were male. Food was the most common trigger (62%), particularly eggs and cow's milk in children aged 3 years and below. In school-age children, nut anaphylaxis was most common in HK and Singapore, but was rare in the other countries, and wheat was the top allergen in Bangkok. Shellfish anaphylaxis was most common in children aged 7-17. Adrenaline was administered in 60% of cases, with 9% given adrenaline before hospital arrival. Adrenaline devices were prescribed in up to 82% of cases in Thailand but none in Qingdao.

CONCLUSIONS

The APRA identified food as the main trigger of anaphylaxis in children, but causative allergens differed even across Asian countries. Fewer than two-thirds of cases received adrenaline treatment, pre-hospital adrenaline usage was low, and adrenaline device prescription remained suboptimal. The registry recognizes an unmet need to strengthen anaphylaxis care and research in Asia-Pacific.

A novel infant microbiome formula (SIM03) improved eczema severity and quality of life in preschool children

Altered gut microbiome composition has been reported in children with eczema and interventions that restore beneficial bacteria in the gut may improve eczema. This open-label pilot study aimed to investigate the efficacy of a novel infant microbiome formula (SIM03) in young children with eczema. Pre-school Chinese children aged 1-5 years old with eczema received SIM03 twice daily for three months. The novelty of SIM03 consists of both the use of a patented microencapsulation technology to protect the viability of unique Bifidobacterium bifidum and Bifidobacterium breve strains identified through big data analysis of large metagenomic datasets of young Chinese children. Paired stool samples at baseline and following SIM03 were analyzed by metagenomics sequencing. Generalized estimating equation was used to analyze changes in eczema severity, skin biophysical parameters, quality of life and stool microbiome. Twenty children aged 3.0 ± 1.6 years (10 with severe eczema) were recruited. Treatment compliance was ≥ 98%. SCORing Atopic Dermatitis score decreased significantly at two months (P = 0.008) and three months (P < 0.001), while quality of life improved significantly at 1, 2, and 3 months. The relative abundance of B. breve and microbial pathways on acetate and acetyl-CoA synthesis were enriched in stool samples at one month (P = 0.0014). Children who demonstrated increased B. bifidum after SIM03 showed improvement in sleep loss (P = 0.045). Relative abundance of B. breve correlated inversely with eczema extent (P = 0.023) and intensity (P = 0.019) only among patients with increased B. breve at Month 3. No serious adverse event was observed. In conclusion, SIM03 is well tolerated. This patented microbiome formula improves disease severity and quality of life in young eczematous children by enhancing the delivery of B. bifidum and B. breve in the gut. SIM03 is a potential treatment option for childhood eczema.

Development and validation of assessment tools for food allergy-related knowledge and management confidence

Background

Given the life-threatening nature of food allergy (FA), it is important to assess the level of knowledge among families with food-allergic patients and their ability to cope with anaphylaxis. This study constructed a FA knowledge questionnaire (FAKQ) and confidence in FA management skills (CIFAMS) questionnaire to assess understanding and attitudes toward FA management in food-allergic families.

Methods

Items from literature review and expert panel showing ≥80% content validity index and semantic equivalence were selected for translation into Chinese. These questionnaires underwent feasibility pilot testing followed by cross-sectional validation to assess their psychometric properties of internal consistency, test-retest reliability, and construct validity with a FA quality-of-life questionnaire and discriminant validity. Exploratory factor analysis was performed to confirm their factor structure.

Results

A total of 155 subjects (104 patients and 51 parents) completed a 20-item FAKQ and 10-item CIFAMS. Both tools showed acceptable internal consistency in baseline and retest groups. FAKQ and CIFAMS correlated for all subjects (P = .002) and for adults (P = .002), and similarly between CIFAMS and parent-reported FA independent measure (P = .005). Total score of FAKQ was sensitive to within-group differences of patients hospitalized for FA (P < .001). FAKQ and CIFAMS items were factored into 4 and 2 domains, respectively. Subjects scored the lowest on FAKQ items about signs of allergic reaction and CIFAMS items on epinephrine autoinjector use.

Conclusion

FAKQ and CIFAMS developed by our group are valid and reliable in assessing knowledge and confidence in FA management in patients and parents. These tools are crucial for formulating education programs and advocacy campaigns for FA.

Early-Life Skin Microbial Biomarkers for Eczema Phenotypes in Chinese Toddlers

Eczema is a common inflammatory skin disorder during infancy. Evidence has shown that skin-microbiome fluctuations may precede eczema development, but their predictive value for eczema phenotypes remains unknown. We aimed to investigate the early-life evolution of the skin microbiome and its temporal associations with different pairs of eczema phenotypes (transient versus persistent, atopic versus non-atopic) in Chinese children. We followed 119 term Chinese infants from birth to 24 months old within a Hong Kong birth cohort. The skin microbes at the left antecubital fossa were serially sampled by flocked swabs at 1, 6, and 12 months for bacterial 16S rRNA gene sequencing. The atopic sensitization at 12 months was strongly associated with eczema persisting to 24 months (odds ratio 4.95, 95% confidence interval 1.29-19.01). Compared with those with non-atopic eczema, the children with atopic eczema had reduced alpha diversity at 12 months (p < 0.001) and transiently higher abundance of the genus Janibacter at 6 months (p < 0.001). Our findings suggest that atopic sensitization at 12 months may predict persistent eczema by 24 months, and atopic eczema at 12 months is associated with unique skin microbiome profiles at 6 and 12 months. Non-invasive skin-microbiome profiling may have predictive value for atopic eczema.

Human milk oligosaccharides in Chinese lactating mothers and relationship with allergy development in offspring

BACKGROUND

The health benefits of breastfeeding are partly contributed by human milk oligosaccharides (HMOs), but there is limited data on breast milk (BM) HMO composition in Chinese.

OBJECTIVE

This study investigated the association between early-life HMO intake and allergy occurrence in Chinese children.

METHODS

103 healthy Chinese pregnant women regardless of allergy history were recruited into this birth cohort. Their babies were followed until 24 months old. Concentrations of 2'-fucosyllactose (2'-FL), lacto-N-neotetraose (LNnT), -sialyllactose (3'-SL) and 6'-sialyllactose (6'-SL) in BM collected at 1-month postpartum were measured by liquid chromatography-mass spectrometry. The associations between these HMOs and allergy occurrence by 24 months were analyzed by multivariate regression analyses.

RESULTS

Twenty-nine percent and 19% of participants had eczema at 12 and 24 months old respectively. Eighty BM samples were analyzed, with 2'-FL being the most abundant HMO (median 1447 ppm, interquartile range [IQR] 291-1906 ppm), and median (IQR) levels of LNnT, 6'-SL and 3'-SL in ppm were 738 (580-950), 20.5 (12.7-38.8) and 23.0 (17.8-27.6) respectively. Participants with eczema by 24 months consumed BM with higher 2'-FL concentration at 1-month (P = 0.008), and also lower 6'-SL concentration in exclusively breastfed infants (P = 0.012) but higher 6'-SL concentration for those with mixed feeding at 1 month (P = 0.043). Food allergic children at 12 months consumed BM with higher 2'-FL concentrations at 1 month (P = 0.048).

CONCLUSIONS

BM 2'-FL concentration is higher in children who develops eczema by 24 months and food allergy during infancy. The relationship for 6'-SL is divergent depending on mode of feeding in infants.

A systematic review of quality and consistency of clinical practice guidelines on the primary prevention of food allergy and atopic dermatitis

Background and aims

With an increasing number of Clinical Practice Guidelines (CPGs) addressing primary prevention of food allergy and atopic dermatitis, it is timely to undertake a comprehensive assessment of the quality and consistency of recommendations and evaluation of their implementability in different geographical settings.

Methods

We systematically reviewed CPGs from 8 international databases and extensive website searches. Seven reviewers screened records in any language and then used the AGREE II and AGREE REX instruments to critically appraise CPGs published between January 2011 and April 2022.

Results

Our search identified 2138 relevant articles, of which 30 CPGs were eventually included. Eight (27%) CPGs were shortlisted based on our predefined quality criteria of achieving scores >70% in the "Scope and Purpose" and "Rigour of Development" domains of the AGREE II instrument. Among the shortlisted CPGs, scores on the "Applicability" domain were generally low, and only 3 CPGs rated highly in the "Implementability" domain of AGREE-REX, suggesting that the majority of CPGs fared poorly on global applicability. Recommendations on maternal diet and complementary feeding in infants were mostly consistent, but recommendations on use of hydrolysed formula and supplements varied considerably.

Conclusion

The overall quality of a CPG for Food Allergy and Atopic Dermatitis prevention did not correlate well with its global applicability. It is imperative that CPG developers consider stakeholders' preferences, local applicability, and adapt existing recommendations to each individual population and healthcare system to ensure successful implementation. There is a need for development of high-quality CPGs for allergy prevention outside of North America and Europe.

PROSPERO registration number

CRD42021265689.

Varying Approaches to Management of IgE-Mediated Food Allergy in Children Around the World

Food allergy is a chronic disease that affects individuals of all ages and is a significant public health problem globally. This narrative overview examines clinical management strategies for IgE-mediated food allergy in children around the world to understand variations in practice. Information was drawn from clinical practice guidelines, recent research, the websites of professional and governmental bodies with expertise in food allergy, and clinical experts from a broad cross-section of geographical regions. The structure and delivery of clinical services, allergen avoidance and food labeling, and resources to support the management of allergic reactions in the community are discussed in detail. The adoption of emerging food immunotherapies is also explored. Wide variations in clinical management of food allergy were apparent across the different countries. Common themes were continuing issues with access to specialist care and recognition of the need to balance risk reduction with dietary and social restrictions to avoid unnecessary detrimental impacts on the quality of life of food allergy sufferers. Findings highlight the need for standardized presentation of practice and priorities, and may assist clinicians and researchers when engaging with government and funding agencies to address gaps.

Validation of the food allergy quality of life questionnaire series in Chinese families with food-allergic children

BACKGROUND

Anxiety from accidental exposure and vigilant dietary monitoring impair the quality of life (QoL) of food-allergic patients. A comprehensive food allergy-specific questionnaire allows patients to accurately report their QoL. This study validated the Food Allergy Quality of Life Questionnaire (FAQLQ) series and assessed the QoL of Chinese food-allergic patients and their caregivers.

METHODS

FAQLQ series developed by EuroPrevall consists of four separate questionnaires for parents, children, adolescents and adults. All questionnaires were translated into traditional Chinese by standard forward and backward methods. A cross-sectional study was conducted on food-allergic patients and children's parents using an age-appropriate questionnaire. The performance indices of FAQLQ and their correlation with independent measures of food allergy were analyzed, and factor analysis was performed to confirm the factor structure of FAQLQ questionnaires.

RESULTS

Cross-sectional validation was performed on 214 participants, with 40 reassessed for test-retest reliability. Overall scores for the FAQLQ series had good internal consistency with Cronbach's α ≥.90. Good construct validity was demonstrated by correlations between FAQLQ-Parent Form, FAQLQ-Child Form, FAQLQ-Teenager Form, FAQLQ-Adult Form and Food Allergy Independent Measure (FAIM) scores, except in 0- to 3-year-old children. Test-retest analyses revealed a significant correlation between total FAQLQ score, parent-reported FAIM and food anxiety domain in 4-6 years, and between total score and FAIM in 7-12 years. Exploratory factor analysis categorized items in the FAQLQ series into three to four domains.

CONCLUSION

FAQLQ series provide a valid and reliable measure for QoL in Chinese food-allergic patients and caregivers, except for parents of children aged 0-3 years. Items for all FAQLQ questionnaires are categorized into different functional domains in our population.

Medium-term Outcomes of Myocarditis and Pericarditis following BNT162b2 Vaccination among Adolescents in Hong Kong

In this study, we examined the clinical and electrophysiological outcomes of adolescents in Hong Kong who developed myocarditis or pericarditis following BNT162b2 vaccination for COVID-19, and followed-up for 60–180 days after their initial diagnosis. Clinical assessments included electrocardiogram (ECG) and echocardiogram at the initial admission and follow-up were compared. Treadmill testing was also performed in some cases. Between 14 June 2021 and 16 February 2022, 53 subjects were approached to participate in this follow-up study, of which 28 patients were followed up for >60 days with a median follow-up period of 100 days (range, 61–178 days) and were included in this study. On admission, 23 patients had ECG abnormalities but no high-grade atrioventricular block. Six patients had echocardiogram abnormalities, including reduced contractility, small rim pericardial effusions, and hyperechoic ventricular walls. All patients achieved complete recovery on follow-up. After discharge, 10 patients (35.7%) reported symptoms, including occasional chest pain, shortness of breath, reduced exercise tolerance, and recurrent vasovagal near-syncope. At follow-up, assessments, including ECGs, were almost all normal. Among the three patients with possible ECG abnormalities, all their echocardiograms or treadmill testings were normal. Sixteen patients (57.1%) underwent treadmill testing at a median of 117 days post-admission, which were also normal. However, at follow-up, there was a significant mean bodyweight increase of 1.81 kg (95%CI 0.47-3.1 kg, p = 0.01), possibly due to exercise restriction. In conclusion, most adolescents experiencing myocarditis and pericarditis following BNT162b2 vaccination achieved complete recovery. Some patients developed non-specific persistent symptoms, and bodyweight changes shall be monitored.

Quality and consistency of clinical practice guidelines on the prevention of food allergy and atopic dermatitis: Systematic review protocol

Background and aims

Allergy prevention strategies have gained significant traction as a means to attenuate the growing burden of allergic diseases over the past decade. As the evidence base for primary prevention of food allergy (FA) and atopic dermatitis (AD) is constantly advancing, clinical practice guideline (CPG) recommendations on interventions for FA and AD prevention vary in quality and consistency among professional organizations. We present a protocol for a systematic review of CPGs on primary prevention of FA and AD.

Methods

We will systematically review and appraise all CPGs addressing primary prevention of FA and AD and report our findings according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Electronic databases and manual website searches from January 2011 to March 2021 without language or geographical restrictions, and supplemented by author contact, will generate the list of potentially relevant CPGs to screen. Evaluation of the methodological quality, consistency, and global applicability of shortlisted CPGs will be performed by members of the Allergy Prevention Work Group of the World Allergy Organization (WAO) using the Appraisal of Guidelines for Research and Evaluation (AGREE) II and AGREE-REX (Recommendations EXcellence). instruments. Guideline contents, consistency, and quality of the recommendations will be summarised in tabular and narrative formats. We aim to present consolidated recommendations from international guidelines of the highest methodological quality and applicability, as determined by AGREE II and AGREE-REX.

Dissemination

This systematic review will provide a succinct overview of the quality and consistency of recommendations across all existing CPGs for FA and AD prevention, as well as crucial perspectives on applicability of individual recommendations in different geographical contexts. Results from this systematic review will be reported in a peer-reviewed journal. It will also inform a position statement by WAO to provide a practical framework to guide the development of future guidelines for allergy prevention worldwide.

Prospero registration number

CRD42021265689.

Temporal Dynamics of the Nasopharyngeal Microbiome and its Relationship with Childhood Asthma Exacerbation

Despite distinct nasopharyngeal microbiome (NPM) profiles between asthmatics and healthy subjects, little is known about the NPM dynamics and its relation to childhood asthma exacerbation (AE). We investigated NPM changes by longitudinally collecting 135 flocked nasopharyngeal swabs (FNPSs) from 33 school-age asthmatic children at six time points (2 to 4-week intervals) from September to December 2017 in Hong Kong. Subjects were categorized into AE and stable asthma (AS) groups according to whether they experienced any exacerbation during follow-up. One-off FNPSs from nine nonasthmatic children were included as controls. Microbiota profiles were analyzed using 16S rRNA gene sequencing. All 144 NPMs were classified into six microbiome profile groups (MPGs), each dominated by Moraxella, Corynebacterium 1, Dolosigranulum, Staphylococcus, Streptococcus, or Anoxybacillus. The microbial diversity and compositions of NPM in exacerbation samples were different from both baseline samples and those from healthy controls. Moraxella and Dolosigranulum-dominated NPM exhibited high temporal stability revealed by MPG transition analysis. NPM diversity decreased whereas microbial composition remained similar over time. The relative abundances of Moraxella increased while Corynebacterium 1, Anoxybacillus, and Pseudomonas decreased longitudinally. However, these temporal patterns did not differ between AE and AS groups, suggesting that short-term dynamic patterns were not sufficient to predict AE occurrence. Asthmatic NPM underwent Moraxella expansion during AE and presented a high microbiome resilience (recovery potential) after AE resolution. Microbial pathways involved in methane, ketone bodies, and vitamin B3 metabolisms were enhanced during AE and primarily contributed by Moraxella. IMPORTANCE Evidence on the dynamic changes of NPM in asthmatic patients remains limited. Here, we present that asthmatic NPMs deviating from a healthy status still showed resilience after disturbance. Our data imply from a longitudinal perspective that Moraxella increase is closely related to AE occurrence. The finding of functional dysbiosis (imbalance) during AE offers a plausible explanation for the known association between nasopharyngeal Moraxella expansion and increased AE risk. This work serves as a basis for future long-term prospective studies leveraging multiomics approaches to elucidate the temporal association between NPM and pediatric AE.

Whole-Genome Shotgun Sequencing for Nasopharyngeal Microbiome in Pre-school Children With Recurrent Wheezing

Microbiome mediates early life immune deviation in asthma development. Recurrent wheeze (RW) in pre-school years is a risk factor for asthma diagnosis in school-age children. Dysbiosis exists in asthmatic airways, while its origin in pre-school years and relationship to RW is not clearly defined. This study investigated metagenomics of nasopharyngeal microbiome in pre-school children with RW. We applied whole-genome shotgun sequencing and human rhinovirus (HRV) detection on nasopharyngeal samples collected from three groups of pre-school children: (i) RW group: 16 children at-risk for asthma who were hospitalized for RW, (ii) inpatient control (IC): 18 subjects admitted for upper respiratory infection, and (iii) community control (CC): 36 children without respiratory syndromes. Sequence reads were analyzed by MetaPhlAn2 and HUMAnN2 algorithm for taxonomic and functional identification. Linear discriminant analysis effect size (LEfSe) analysis was used to identify discriminative features. We identified that Moraxella catarrhalis and Dolosigranulum pigrum were predominant species in nasopharynx. RW had lower alpha diversity (Shannon diversity index) than CC (0.48 vs. 1.07; P_adj = 0.039), characterized by predominant Proteobacteria. LEfSe analysis revealed D. pigrum was the only discriminative species across groups (LDA = 5.57, P = 0.002), with its relative abundance in RW, IC, and CC being 9.6, 14.2, and 37.3%, respectively (P < 0.05). LEfSe identified five (ribo)nucleotides biosynthesis pathways to be group discriminating. Adjusting for HRV status, pre-school children with RW have lower nasopharyngeal biodiversity, which is associated with Proteobacteria predominance and lower abundance of D. pigrum. Along with discriminative pathways found in RW and CC, these microbial biomarkers help to understand RW pathogenesis.

Prospective study of disease persistence and lung function trajectories of childhood asthma

BACKGROUND

A proportion of asthmatic children outgrow their disease by adulthood, but there are limited data on predictors for asthma persistence. This prospective study characterized the trajectory of spirometric indices and identified predictors for the persistence of childhood asthma.

METHODS

Chinese asthmatic children aged 6-15 years from pediatric allergy clinic underwent annual visits for ≥5 years and until their adulthood. Pre-bronchodilator spirometry and anti-asthma medications were recorded at baseline and then at least annually. Asthma resolution was defined when patients were free from asthma symptoms and use of anti-asthma drugs for ≥2 years. Logistic regression was used to identify predictors for asthma persistence. Generalized estimating equation was used to analyze longitudinal changes in lung function parameters in relation to asthma persistence.

RESULTS

181 asthmatic children aged [mean (SD)] 10.0 (2.7) years were followed for [mean (SD)] 12.5 (2.8) years. One third of them outgrew asthma during follow-up. Female was 3.36 times more likely to have persistent asthma. Inhaled corticosteroid (ICS) treatment ever and frequent asthma exacerbation (AE) predicted asthma persistence with respective odds ratios of 3.19 (95% confidence interval [CI] 1.44-7.09) and 3.05 (95% CI 1.39-6.68). Persistent asthma was inversely associated with baseline forced expiratory volume in 1-second (FEV₁ %) with an odds ratio of 0.96 (95% CI 0.93-1.00). Throughout follow-up, patients with persistent asthma had generally lower forced expiratory indices than those with asthma resolution. Children with persistent asthma experienced poorer lung function growth.

CONCLUSIONS

Female, ICS ever, and frequent AE predicted persistent asthma. Patients with persistent asthma had lower forced expiratory indices and poorer lung function growth into adulthood.

Women in science and medicine

Science and medicine know no barriers, no country, no language. They are universal tools for the benefit of humankind meant to be accessible to everyone, both men and women. As women physician scientists, we all have had our own journeys wanting to be part of science and medicine.

Epidemiology of Acute Myocarditis/Pericarditis in Hong Kong Adolescents Following Comirnaty Vaccination

BACKGROUND

Age-specific incidence of acute myocarditis/pericarditis in adolescents following Comirnaty vaccination in Asia is lacking. This study aimed to study the clinical characteristics and incidence of acute myocarditis/pericarditis among Hong Kong adolescents following Comirnaty vaccination.

METHODS

This is a population cohort study in Hong Kong that monitored adverse events following immunization through a pharmacovigilance system for COVID-19 vaccines. All adolescents aged between 12 and 17 years following Comirnaty vaccination were monitored under the COVID-19 vaccine Adverse Event Response and Evaluation Programme. The clinical characteristics and overall incidence of acute myocarditis/pericarditis in adolescents following Comirnaty vaccination were analysed.

RESULTS

Between 14 June 2021 and 4 September 2021, 33 Chinese adolescents who developed acute myocarditis/pericarditis following Comirnaty vaccination were identified. 29 (87.88%) were males and 4 (12.12%) were females, with a median age of 15.25 years. 27 (81.82%) and 6 (18.18%) cases developed acute myocarditis/pericarditis after receiving the second and first dose, respectively. All cases are mild and required only conservative management.The overall incidence of acute myocarditis/pericarditis was 18.52 (95% Confidence Interval [CI], 11.67-29.01) per 100,000 persons vaccinated. The incidence after the first and second doses were 3.37 (95%CI 1.12-9.51) and 21.22 (95%CI 13.78-32.28 per 100,000 persons vaccinated, respectively. Among male adolescents, the incidence after the first and second doses were 5.57 (95% CI 2.38-12.53) and 37.32 (95% CI 26.98-51.25) per 100,000 persons vaccinated.

CONCLUSIONS

There is a significant increase in the risk of acute myocarditis/pericarditis following Comirnaty vaccination among Chinese male adolescents, especially after the second dose.

Identification of predictors for persistence of immediate-type egg allergy in Chinese children

Background

Egg allergy is one of the most common food allergies in childhood with increasing prevalence in Hong Kong. While ample studies were published on its optimal diagnosis, there was limited data on predictors for the natural history of egg allergy in Asian populations.

Objective

This study aimed to characterize the clinical course and outcome of children with egg allergy and identify its prognostic factors.

Methods

All Chinese children with immediate-type egg allergy being followed since ≥3 years old in allergy clinic of our university-affiliated teaching hospital were reviewed to determine if they outgrew egg allergy at the latest follow-up. The predictive values of clinical and atopic factors for resolution of egg allergy were analyzed on Kaplan-Meier curves, and factors independently associated with persistent egg allergy was analyzed by logistic regression.

Results

Seventy-six patients with median (interquartile range) age 8.9 years (6.3–13.0 years) were recruited. They initially presented with egg-allergic reactions at 1.0 years (0.7–1.7 years). Fifty-four children (71%) were able to tolerate egg at a median of 36 months from initial reaction. Patients with concomitant peanut allergy and those with initial reaction at ≥1 year old were more likely to have persistent egg allergy (p = 0.015 and p = 0.027 respectively). Skin prick test wheal ≥6 mm to egg yolk and egg white individually as well as to both egg yolk and egg white were predictors for egg allergy persistence (respective, p < 0.001, p = 0.001, and p = 0.001 by log-rank tests). Logistic regression showed that initial SPT ≥ 6 mm to egg yolk was the only independent predictor for persistent egg allergy (B = 2.59 ± 0.98, p = 0.008).

Conclusion

Most Chinese children with immediate-type egg allergy can tolerate egg in long run. SPT wheal size to egg, concomitant peanut allergy and initial presentation after infancy may predict egg allergy persistence.

Molecular and immunological characterization of grass carp (Ctenopharyngodon idella) parvalbumin Cten i 1: A major fish allergen in Hong Kong

BACKGROUND

Grass carp is the most commonly consumed fish species in Hong Kong. The allergenicity of grass carp and its allergen content are yet to be reported. This study characterized the major allergen in grass carp and investigated its allergenicity.

METHODS

Sixty-nine subjects with history of IgE-mediated allergic reaction to grass carp were recruited. The protein content in steamed grass carp extract was resolved by SDS-PAGE, and the major allergen was identified by immunoblotting with serum from subjects allergic to grass carp. The identity of allergen was elucidated by mass spectrometry and amino acid sequence obtained by amplifying the specific gene from cDNA library of grass carp. The cross-reactivity between parvalbumins from grass carp and other phylogenetically close (common carp) or commercially important (cod and salmon) species was investigated by competitive inhibition ELISA.

RESULTS

A major IgE-binding protein was found at approximately 9 kDa and identified as parvalbumin by immunoblotting and mass spectrometry. Grass carp parvalbumin was more allergenic than common carp, salmon, and cod parvalbumins despite sharing high sequence homology. This newly identified major allergenic parvalbumin isoform from grass carp was registered as Cten i 1 in the World Health Organization and International Union of Immunological Societies allergen database.

CONCLUSIONS

Grass carp parvalbumin is identified as the major fish allergen in Hong Kong. The strong allergenicity of Cten i 1 contributes to the high IgE reactivity of grass carp. Grass carp, among other fish species, should be considered when managing fish-allergic patients.

Cadherin-related family member 3 gene impacts childhood asthma in Chinese children

BACKGROUND

A missense variant (rs6967330) of the gene encoding cadherin-related family member 3 (CDHR3) was associated with recurrent severe exacerbations in pre-schoolers. However, there were limited data on its relationship with pre-school lung function and school-age asthma. This study replicated the association between polymorphic markers at the region of CDHR3 around rs6967330 and wheezing phenotypes in two independent cohorts of Chinese children.

METHODS

Ten tagging SNPs located 10 kb around rs6967330 were selected by HaploView 5.0 based on 1000 Genomes database for Southern Han Chinese. Their associations with wheezing and lung function were examined in 1341 Chinese pre-school children, while those for asthma phenotypes were examined in an independent group of 2079 school-age children. Genotypic and haplotypic associations were analyzed by multivariate regression, and generalized multifactor dimensionality reduction was used to examine epistatic interactions for wheezing traits.

RESULTS

The mean (SD) age of pre-school cohort was 4.7 (1.0) years. Rs6967330 was associated with current wheeze (odds ratio [OR] 1.63, 95% confidence interval [CI] 1.09-2.43) and its severity (OR 1.64, 95% CI 1.10-2.44) among pre-school children. This SNP was also associated with school-age asthma (OR 1.32, 95% CI 1.04-1.69). The minor allele of rs408223 was associated with lower FEV_0.5 (β = -2.411, P = .004) and FEV_0.5 /FVC (β = -1.292, P = .015). Lower spirometric indices were also associated with minor allele of rs140154310. GAC haplotype from rs4730125, rs6967330, and rs408223 was associated with pre-school current wheeze and school-age asthma. Epistatic interaction was found between unrelated CDHR3 SNPs for FEV_0.5 among pre-schoolers.

CONCLUSION

CDHR3 is a candidate gene for early-life wheezing, school-age asthma, and lung function in Chinese children.

Allergen immunotherapy for food allergy from the Asian perspective: key challenges and opportunities

Introduction: Prevalence of food allergy is rising in different regions of the world. Asia has not been spared from this epidemic, but epidemiological data have revealed a different pattern of food allergens in this continent. Allergen-specific immunotherapy (AIT) for food allergy, which has been revolutionary as the main focus of research in recent years, needs to be adapted for the different populations in Asia. Areas covered: Recent evidence shows increasing popularity and superiority of AIT over strict food avoidance as the cornerstone of food allergy management. Asia is a distinctive continent with specific food allergy triggers, in particular, seafood, and wheat. Peanut, on the contrary, is not a common food allergen in most parts of Asia. The common Asian food allergens, as well as the rapidly developing food-specific AIT in this region will be covered in this article. Expert commentary: Evidence on oral immunotherapy for wheat allergy and preclinical data on shellfish AIT are promising. Further work should be done on resolving cross-sensitization between environmental allergens with wheat and shellfish allergens, and a modified AIT approach to enhance the safety and effectiveness of food-specific immunotherapy.