Allergic rhinitis in Chinese young adults from the Singapore/Malaysia cross-sectional genetics epidemiology study (SMCGES) cohort: Prevalence, patterns, and epidemiology of allergic rhinitis

Exploring geographical variances in component-resolved diagnosis within the Asia-Pacific region

Component-resolved diagnostics (CRD) have revolutionized allergy diagnosis, offering enhanced accuracy and insights into allergen sensitization patterns. This review explores geographical variances in CRD for food and aeroallergens across the Asia-Pacific region. We examine the varying prevalence of allergic diseases and the utility of CRD in diagnosing common food allergies, including peanut, shellfish, fish, wheat, and fruits. Notable differences in serum-specific (sp)IgE sensitization patterns and the clinical relevance of particular allergen components are observed between populations in Asian countries and those in Europe and the United States. For food allergies, the literature reports significant differences in allergen components and their diagnostic utility across various countries. Peanut allergy diagnostics, particularly Ara h 2 spIgE, show varying sensitivity and specificity between Asian and Western populations. In shellfish allergy, emerging allergens beyond tropomyosin are gaining importance in the Asia-Pacific region. Fish and wheat allergies also demonstrate unique sensitization patterns, emphasizing the need for region-specific diagnostic approaches. Regarding aeroallergens, pollen sensitization profiles vary widely across the region, influenced by local flora and climate, to influence symptoms of pollen food allergy syndrome. House dust mite allergens remain a significant concern, with high sensitization rates to major components like Der p 1, Der p 2, and the emerging Der p 23. The cross-reactivity between house dust mite and shellfish allergens is particularly relevant in this region. These findings emphasize the need for region-specific CRD approaches, considering local allergen profiles and sensitization patterns. As the prevalence of allergic diseases continues to rise in the Asia-Pacific, further research into locally relevant allergens and their components is crucial for improving diagnosis, patient management, and targeted immunotherapy strategies in this diverse region.

Genetic determinants of skin ageing: a systematic review and meta-analysis of genome-wide association studies and candidate genes

BACKGROUND

Skin ageing is influenced by complex genetic factors. Various phenotypes such as wrinkling, pigmentation changes, and skin cancers have been linked to specific genetic loci. However, the underlying genetic mechanisms and pathways remain poorly understood. This systematic review and meta-analysis aims to summarise the genetic loci found to be associated with skin ageing phenotypes by published genome-wide association studies (GWAS) and candidate gene studies. We also evaluated the overall association of loci via meta-analysis and identified the association patterns to explore potential biological pathways contributing to skin ageing. The Web of Science, Embase, and PubMed databases were searched on January 2024 using specific exclusion criteria (e.g., study of non-human subjects, focus on skin diseases, or treatments) to identify relevant articles. There did not appear to be any significant publication bias observed across the all phenotypes.

MAIN BODY

A total of 48 studies were included, revealing 30 loci that were confirmed to be associated with skin ageing by multiple studies (e.g., AFG3L1P: odds ratio 1.133 95% confidence interval [1.044, 1.222]; BPIFA3: 1.859 [1.567, 2.151]; CLPTML1: 1.164 [1.0.99, 1.229]; CPNE7: 0.905 [0.852-0.958]; DEF8: 1.186 [1.042, 1.331]; IRF4: 1.260 [1.025, 1.495]; MYO16: 2.303 [1.697, 2.908]; PRDM16: 1.105 [1.084, 1.127]; RORA: 1.391 [1.206, 1.577]; SPG7: 0.922 [0.897, 0.947]; SPON1: 2.214 [1.204, 3.225]; SPTLC1: 1.464 [1.432, 1.495]; TYR: 1.175 [1.007, 1.343]). The lack of significance for many loci may be due to studies analysing different SNPs within the same locus, weakening the overall associations. Several loci were associated with specific phenotypic categories (e.g., skin colour related, skin cancer related, wrinkling and sagging related), suggesting shared biological pathways are involved in the pathogenesis of different skin ageing phenotypes. This pattern was also observed in several of the loci that do not have a significant overall association with skin ageing.

CONCLUSION

Despite significant heterogeneity among the included studies and the use of subjective visual methods for phenotype assessment, our review highlights the critical role of fundamental biological processes, such as development and cellular organisation, in skin ageing. Future research that targets the same SNP across multiple populations could strengthen the association of additional loci with skin ageing. Further investigation into these underlying biological processes would significantly advance our understanding of the pathogenesis of skin ageing phenotypes.

A broad assessment of forty-one skin phenotypes reveals complex dimensions of skin ageing

BACKGROUND

Skin ageing takes on many different forms. Despite this diversity in skin ageing phenotypes, literature published to date is limited in scope, as many research studies either focus on one single phenotype or just a few specific phenotypes. Presently, phenotypes such as wrinkles, pigment spots, and photo-ageing are receiving most of the research attention. We therefore wonder whether the current discourse on skin ageing places a disproportionate amount of focus on a few selected phenotypes, leaving other skin ageing phenotypes underexplored.

METHODS

In this cross-sectional study, we performed a broad assessment of forty-one signs of skin ageing and characterised the phenotypes that constituted key components of skin ageing. We also explored the interrelationship among forty-one skin ageing phenotypes using Spearman's Correlation and Principal Component Analysis.

RESULTS

We analysed our study population, which is composed of 3281 ethnic Chinese participants from the Singapore/Malaysia Cross-sectional Genetics Epidemiology Study (SMCGES). The first ten principal components cumulatively explain 46.88% of the variance of skin ageing phenotypes in our study population. We discovered that the commonly discussed forms of skin ageing (i.e., wrinkles, pigmentation, and photo-ageing) only accounted for a small portion (24.39%) of the variance of all skin ageing phenotypes in our study population. Telangiectasia, a poor lip fullness, a lighter skin colour, xerosis, ephelides (freckles), ptosis of eyelids (droopy eyelids), eyebags, and a low eyebrow positioning were other key components of skin ageing, accounting for a further 22.49% of the variance of skin ageing phenotypes in our study population. We found that each of these ten skin ageing phenotypes characterises a key and important aspect of skin ageing. In this broad assessment of skin ageing, we first described the prevalence of forty-one signs of skin ageing and then characterised in detail both the prevalence and severity distribution of ten key skin ageing phenotypes.

CONCLUSIONS

We presented clear evidence that skin ageing is much more than just wrinkles, pigmentation and photo-ageing. The addition of telangiectasia, poor lip fullness, a lighter skin colour, xerosis, ephelides, ptosis of eyelids, eyebags, and a low eyebrow positioning added more dimensions to skin ageing phenotype presentations.

Comparisons between Caucasian-validated and Chinese-validated photo-numeric scales for assessing facial wrinkles

Skin ageing results in wrinkling. In this study, we discuss four types of facial wrinkles: Crow's Feet wrinkles, forehead wrinkles, glabellar frown wrinkles, and nasolabial folds. These four phenotypes can be assessed either with a photo-numeric scale developed and validated on Caucasian skin (i.e., Caucasian scale) or with a photo-numeric scale developed and validated on Chinese skin (i.e., Chinese scale). As Caucasian and Chinese skin have inherent differences, the main objective of this study is to determine whether these inherent differences affect the suitability of evaluating facial wrinkles on ethnic Chinese skin with a Caucasian scale. Three trained assessors studied four types of wrinkles on the faces of 1,081 ethnic Chinese young adults from the Singapore/Malaysia Cross-sectional Genetics Epidemiology Study (SMCGES). We found that Caucasian scales and Chinese scales are concordant (Spearman's Rank Correlation (ρ) values: 0.53-0.80) and the level of agreement between the Caucasian scales and Chinese scales is moderately high (Cohen's Kappa (κ) values: 0.40-0.49). When tested on ethnic Chinese skin, both the Caucasian scale and the Chinese scale are largely consistent in showing presence or absence of a given facial wrinkle (Area under curve (AUC) values: 0.79-0.90). All assessors are highly internally consistent (Weighted Kappa (κw) values: 0.686-0.992). Our results build confidence that four types of facial wrinkles on ethnic Chinese faces can be assessed with Caucasian scales. To the best of our knowledge, Chinese scales for facial wrinkles beyond the four types discussed here have yet to be developed. Caucasian scales for these other facial wrinkles will also need to be tested for their suitability to be used on ethnic Chinese skin as and when more Chinese scales are developed.

The burden of allergic rhinitis is undermanaged in a large proportion of Chinese young adults from Singapore

Background

Allergic rhinitis (AR) is a nasal disorder characterized by the simultaneous manifestation of at least 2 out of 4 possible symptoms: rhinorrhea, nasal itching, nasal pruritus, and sneezing. Presently, among Chinese young adults from Singapore, we characterised AR phenotypes, established Total Nasal Symptom Score (TNSS) baselines, and examined the management of AR.

Methods

Participants completed an investigator-administered International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire and underwent a skin prick test (SPT). Individuals exhibiting sensitization during the SPT while having at least 2 rhinitis symptoms were identified as AR cases, then categorized into Allergic Rhinitis in Asthma (ARIA) classifications.

Results

There were 9323 subjects analyzed. AR prevalence was estimated at 35.4%. Rhinorrhea was perceived as the most severe (mean Nasal Symptom Score (mNSS) ± SD: 1.42 ± 0.74), while nasal pruritus was the least severe (mNSS ± SD: 1.24 ± 0.68). Among moderate-severe AR (68.1%), most were affected by either troublesome symptoms (27.7%) or sleep disturbances (18.4%). By ARIA classes, 26.6% were mild intermittent, 5.4% were mild persistent, 50.3% were moderate-severe intermittent, and 17.6% were moderate-severe persistent. The mean TNSS (mTNSS) of AR cases was 4.43 (SD = 2.49) and between AR classifications, the mTNSS was significantly different. Notably, a large proportion of AR cases remained undiagnosed (85.2%), untreated (72.5%), or both (65.4%); 19.8% self-medicated for AR.

Conclusions

There was a significant difference in TNSS of the AR phenotypes, and among phenotypes with a higher mTNSS, a large proportion remained untreated, undiagnosed, or both. The evidence indicates an existing burden of AR among Chinese young adults in Singapore which is notably undermanaged.

A meta-analysis of the prevalence and risk of mental health problems in allergic rhinitis patients

OBJECTIVE

Allergic rhinitis (AR), a prevalent global health concern, is increasingly recognized for its impact beyond physical symptoms, affecting mental health. This research examined the extent of AR's psychological burden and sleep disturbances.

METHODS

A systematic search of four databases yielded 49 studies reporting mental health problems in 18,269,265 individuals (15,151,322 AR patients and 3,117,943 controls). The primary outcomes included all mental health problems in AR patients. Subgroup analyses based on outcome and AR severity, country, AR diagnosis, recruitment setting, and age were performed. Secondary outcomes included the risk of these problems compared to controls (healthy or without AR).

RESULTS

In AR, depression (25%), anxiety (25%), stress (65%), distress (57%), suicidal thoughts (14%) and attempts (4%), poor sleep quality (48%), insomnia (36%), sleep impairment (33%), and insufficient sleep duration <7 h (59%) were prevalent. The severity of these outcomes differed significantly. Patients' country, AR diagnostic method, recruitment method/setting, and age group were significant effect modifiers. Compared to controls, AR resulted in significantly higher risk of depression, anxiety, stress, suicidal attempts and thoughts, insomnia, and sleep impairment.

CONCLUSION

AR patients had significantly lower sleep duration. Mental health problems are very common among AR patients, further exacerbating their sleep quality and duration and intention to suicide.

Functional Polymorphisms Regulate FOXO1 Transcript Expression and Contribute to the Risk and Symptom Severity of HDM-Induced Allergic Rhinitis

INTRODUCTION

FOXO1 plays an important role in regulating immune processes that contribute to allergic inflammation; however, genetic variants influencing FOXO1 expression in AR pathogenesis remains unclear. This study aimed to investigate the functional effect of FOXO1 single nucleotide polymorphisms (SNPs) on AR development by performing genetic association and functional analysis studies.

METHODS

This study belongs to a part of an ongoing Singapore/Malaysia cross-sectional genetics and epidemiological study (SMCSGES). We assessed the associations of FOXO1 transcript expression levels in peripheral blood mononuclear cells (PBMC) with AR phenotype, total nasal symptom score (TNSS), and SNP genotype in a sub-cohort of n = 658 individuals from the SMCSGES population. Associations of FOXO1 SNPs with AR were assessed in a cohort of n = 5,072 individuals from the SMCSGES population. In vitro promoter luciferase assay was used to evaluate the effect of AR-associated SNPs on FOXO1 promoter activity.

RESULTS

FOXO1 transcript expression in PBMC was significantly associated with the risk of AR (p < 0.05) and TNSS among AR patients (p < 0.0001). We identified a significant association between tag-SNPs rs9549246 and FOXO1 transcript expression in PBMC from the SMCSGES sub-cohort and the multiethnic eQTLGen consortium (false discovery rate-adjusted p < 0.05). The minor allele "A" of tag-SNP rs9549246 was significantly associated with a higher risk of AR (p = 0.04422, odds ratio = 1.21, 95% confidence interval = 1.01-1.45) in the SMCSGES genotyping cohort (n = 5,072). In vitro luciferase assay showed the minor allele "A" of rs35594717 (tagged by rs9549246) was significantly associated with a higher FOXO1 promoter activity (p < 0.05).

CONCLUSION

FOXO1 transcript expression in PBMC has a strong association with the risk and symptom severity of AR. Genetic variants tagged by rs9549246 were shown to affect the expression of FOXO1 and contribute to the development of AR in the SMCSGES population.

Comparisons between wrinkles and photo-ageing detected and self-reported by the participant or identified by trained assessors reveal insights from Chinese individuals in the Singapore/Malaysia Cross-sectional Genetics Epidemiology Study (SMCGES) cohort

BACKGROUND

Changes develop on the facial skin as a person ages. Other than chronological time, it has been discovered that gender, ethnicity, air pollution, smoking, nutrition, and sun exposure are notable risk factors that influence the development of skin ageing phenotypes such as wrinkles and photo-ageing. These risk factors can be quantified through epidemiological collection methods. We previously studied wrinkles and photo-ageing in detail using photo-numeric scales. The analysis was performed on the ethnic Chinese skin by three trained assessors. Recent studies have shown that it is possible to use self-reported data to identify skin-related changes including skin colour and skin cancer. In order to investigate the association between risk factors and skin ageing phenotypic outcomes in large-scale epidemiological studies, it would be useful to evaluate whether it is also possible for participants to self-report signs of ageing on their skin.

AIM

We have previously identified several validated photo-numeric scales for wrinkling and photo-ageing to use on ethnic Chinese skin. Using these scales, our trained assessors grade wrinkling and photo-ageing with moderately high inter-assessor concordance and agreement. The main objective of this study involves letting participants grade self-reported wrinkling and photo-ageing using these same scales. We aim to compare the concordance and agreement between signs of skin ageing by the participant and signs of ageing identified by our assessors.

METHOD

Three trained assessors studied facial photo-ageing on 1081 ethnic Chinese young adults from the Singapore/Malaysia Cross-sectional Genetics Epidemiology Study (SMCGES) cohort. Self-reported facial photo-ageing data by the same 1081 participants were also collated and the two sets of data are compared.

RESULTS

Here, we found that self-reported signs of photo-ageing are concordant with photo-ageing detected by our assessors. This finding is consistent whether photo-ageing is evaluated through studying wrinkle variations (Spearman's rank correlation (ρ) value: 0.246-0.329) or through studying dyspigmentation patterns (Spearman's rank correlation (ρ) value 0.203-0.278). When studying individual wrinkles, both participants and assessors often detect the presence of the same wrinkle (Spearman's rank correlation (ρ) value 0.249-0.366). A weak-to-fair level of agreement between both participants and assessors (Cohen's kappa (κ) values: 0.041-0.233) persists and is statistically significant after accounting for agreements due to chance. Both the participant and the assessor are largely consistent in evaluating the extent of photo-ageing (area under curve (AUC) values 0.689-0.769) and in discerning between the presence or absence of a given facial wrinkle (area under curve (AUC) values 0.601-0.856).

CONCLUSION

When we analyse the overall appearance of the face, our results show that signs of photo-ageing identified by the participant are concordant with signs of photo-ageing identified by our assessors. When we focused our analysis on specific areas of the face, we found that participants were more likely to identify and self-report the same wrinkles that our assessors have also detected. Here, we found that self-reported signs of skin ageing provide a satisfactory approximation to the signs of skin ageing identified by our assessors. The ability to use self-reported signs of skin ageing should also be evaluated on scales beyond the ones discussed in this study. Currently, there are not as many photo-numeric scales for quantifying dyspigmentation patterns as there are for quantifying wrinkle variations. As Chinese skin is known to become dyspigmented more easily with age, more photo-numeric scales need to be developed and properly validated.

Comparisons between Caucasian-validated photo-numeric scales and Korean-validated photo-numeric scales for photo-ageing. Insights from the Singapore/Malaysia cross-sectional genetics epidemiology study (SMCGES) cohort

BACKGROUND

Photo-ageing is a form of skin ageing which affects the entire face. A photo-aged skin has a diverse variety of wrinkles and dyspigmentation all over the face. Here, we discuss photo-ageing on the Chinese skin evaluated using a photo-numeric scale developed and validated on Caucasian skin (i.e., Caucasian scale) and evaluated using a photo-numeric scale developed and validated on Korean skin (i.e., Korean scale). The Korean scale can be subdivided into two scales that separately address the wrinkling and dyspigmentation constituents of photo-ageing.

AIM

As there are currently no photo-ageing scales for Chinese skin, the main objective of this study is to adapt existing photo-ageing photo-numeric scales for use on ethnic Chinese skin.

METHOD

Three trained assessors studied facial photo-ageing on 1,081 ethnic Chinese young adults from the Singapore/Malaysia Cross-sectional Genetics Epidemiology Study (SMCGES) cohort.

RESULTS

All assessors are highly internally consistent (Weighted Kappa (κw) values≥0.952). We found that the Caucasian scale and Korean scale give nearly synonymous results for the wrinkling constituent of photo-ageing (R2 = 0.9386). The two scales are strongly concordant (Spearman's Rank Correlation (ρ) value: 0.62 ± 0.06, p = 1.31×10-84). A weak-to-moderate inter-scalar level of agreement (Cohen's Kappa (κ) values: 0.38 ± 0.05, p = 8.87×10-53) persists and is statistically significant after accounting for agreements due to chance. When tested on ethnic Chinese skin, both scales detect photo-ageing consistently (Area under curve [AUC] values: 0.76-0.84). Additionally, the Korean scale for the dyspigmentation constituent of photo-ageing is concordant with both the Caucasian scale (R2 = 0.7888) and the Korean scale for the wrinkling constituent of photo-ageing (R2 = 0.7734).

CONCLUSION

Our results show that the Caucasian scale is suitable for capturing photo-ageing on Chinese skin, especially wrinkle variations. The Korean dyspigmentation scale supplements the Caucasian scale to capture dyspigmentation patterns on Chinese skin that may be absent on Caucasian skin. Currently, photo-ageing scales for Chinese skin are absent. When developed, these photo-ageing scales must be properly validated for their ability to capture photo-ageing of the entire face.

Identification of rBlo t 41 with a chitin-binding type-2 domain: A novel major allergen from Blomia tropicalis

BACKGROUND

Blomia tropicalis (B. tropicalis) has been reported to impose an increased risk of allergic diseases. However, few characteristics of the unknown allergen components responsible for B. tropicalis allergy and clinical relevance have been fully identified.

METHODS

We synthesized and characterized the physicochemical properties and cross-reactivity of the newly discovered recombinant B. tropicalis group 41 allergen (rBlo t 41). Subsequently, sera were collected from 107 B. tropicalis allergic subjects to evaluate the prevalence of the rBlo t 41. Lastly, its allergenicity was tested in humans by basophil activation assays, and in mice by a model of allergic asthma.

RESULTS

The mature protein of rBlo t 41 was described as 104 amino acids long and 15.8 kDa, and its limited cross-reactivity was observed between allergens of house dust mites (HDM). Sensitization rate of rBlo t 41 (56.07 %) was lower than rBlo t 2 (76.29 %) and rBlo t 5 (69.07 %) in our study. Besides, rBlo t 41 elicited CD63 upregulation in basophils, whereas rBlo t 41-sensitized mice generated rBlo t 41-IgE and developed allergic airway inflammation after allergen exposure. Of note, component-based tests showed a high area under curve value (AUC = 0.75) of rBlo t 41, displaying its favorable diagnostic potential in B. tropicalis allergy.

CONCLUSIONS

rBlo t 41 was identified as a candidate novel major allergen with good diagnostic potential in B. tropicalis sensitization. Additionally, we provided strong evidence about rBlo t 41 on the clinically relevant manifestations in B. tropicalis allergies, conducive to facilitating the development of component-resolved diagnosis.

Comparisons between eyebags, droopy eyelids, and eyebrow positioning identified by photo-numeric scales or identified by written descriptive scales: Insights from the Singapore/Malaysia cross-sectional genetics epidemiology study (SMCGES) cohort

BACKGROUND

We evaluate skin sagging phenotypes (eyebags, droopy eyelids, low eyebrow positioning) using written descriptive scales and photo-numeric scales. We also study how anti-ageing interventions and digital screen time influence skin sagging.

AIM

We compare the two phenotype assessment methods with each other.

METHOD

Skin sagging and personal lifestyle data obtained from 2885 ethnic Chinese young adults from the Singapore/Malaysia cross-sectional genetics epidemiology study (SMCGES) cohort were collated and compared.

RESULTS

Significant correlations (p-value < 0.001) between written descriptive scales and photo-numeric scales were observed for eyebags (0.25) and eyebrow positioning (0.08). Significant correlations (p-value < 0.001) were observed after combining both scales for eyebags (0.38), droopy eyelids (0.30), and eyebrow positioning (0.30). Anti-ageing interventions are associated with delayed progression of eyebags from 18-45 years old, droopy eyelids from 31-45 years old, and eyebrow positioning from 35-40 years old. Significantly lower (p-value < 0.02) eyebrow positioning is associated with both <1 and 1-3 h of screen time stratified by age.

CONCLUSION

Written descriptive scales provide comparable results to photo-numeric scales. However, validating and adapting photo-numeric scales for different populations identifies phenotypes better. Anti-ageing interventions are beneficial at different age ranges. Screen time is associated with skin sagging in young (18-30 years old) participants.

Sleep and allergic diseases among young Chinese adults from the Singapore/Malaysia Cross-Sectional Genetic Epidemiology Study (SMCGES) cohort

BACKGROUND AND OBJECTIVE

Sleep disruption has been shown to affect immune function and thus influence allergic disease manifestation. The specific effects of sleep on allergic diseases, however, are less well-established; hence, in a unique population of young Chinese adults, we investigated the association between sleep and allergic disease.

METHODS

Young Chinese adults recruited from Singapore in the Singapore/Malaysia Cross-Sectional Genetic Epidemiology Study (SMCGES) were analyzed. We used the International Study of Asthma and Allergies in Childhood (ISAAC) protocol and a skin prick test to determine atopic dermatitis (AD), allergic rhinitis (AR), and asthma status. Information regarding total sleep time (TST) and sleep quality (SQ) was also obtained.

RESULTS

Of 1558 participants with a mean age of 25.0 years (SD = 7.6), 61.4% were female, and the mean total sleep time (TST) was 6.8 h (SD = 1.1). The proportions of AD, AR, and asthma were 24.5% (393/1542), 36.4% (987/1551), and 14.7% (227/1547), respectively. 59.8% (235/393) of AD cases suffered from AD-related sleep disturbances, 37.1% (209/564) of AR cases suffered from AR-related sleep disturbances, and 25.1% (57/227) of asthma cases suffered from asthma-related sleep disturbances. Only asthma cases showed a significantly lower mean TST than those without asthma (p = 0.015). Longer TST was significantly associated with lower odds of AR (OR = 0.905, 95% CI = 0.820-0.999) and asthma (OR = 0.852, 95% CI = 0.746-0.972). Linear regression analyses showed that lower TST was significantly associated with asthma (β =  - 0.18, SE = 0.076, p-value = 0.017), and AR when adjusted for AR-related sleep disturbances (β =  - 0.157, SE = 0.065, p-value = 0.016). Only sleep disturbances due to AR were significantly associated with a poorer SQ (OR = 1.962, 95% CI = 1.245-3.089).

CONCLUSIONS

We found that sleep quality, but not sleep duration was significantly poorer among AD cases, although the exact direction of influence could not be determined. In consideration of the literature coupled with our findings, we posit that TST influences allergic rhinitis rather than vice versa. Finally, the association between TST and asthma is likely mediated by asthma-related sleep disturbances, since mean TST was significantly lower among those with nighttime asthma symptoms. Future studies could consider using objective sleep measurements coupled with differential expression analysis to investigate the pathophysiology of sleep and allergic diseases.

Sensitization to oil palm pollen associates with risks and severity of allergic diseases

Background

Elaeis guineensis (Ela g, oil palm) pollen is one of the most predominant species of inhalant allergens in the tropical Southeast Asia region; however, its association with the manifestation of allergic diseases remains largely unexplored. This study aimed to determine the sensitization pattern of oil palm pollen and associate this with the risk and severity of allergic diseases.

Methods

Participants were recruited as a part of the Singapore and Malaysia cross-sectional genetic and epidemiological study (SMCSGES). Two independent cohorts were recruited: n = 564 serum samples were collected and serological assessment was performed against a panel of 16 crude inhalant allergens including house dust mite, pet, insect, pollen, and fungal allergens; n = 13 652 Singapore/Malaysia Chinese young adults were recruited and skin prick test was used to assess oil palm sensitization, which was tested for its association with the risk and severity of asthma, allergic rhinitis (AR), and atopic dermatitis (AD).

Results

The sensitization rate of oil palm pollen is 9.6% in the n = 564 Singapore/Malaysia cohort. In the n = 13 652 Singapore/Malaysia Chinese cohort, oil palm sensitization significantly associates with increased risks of asthma (p = 1.34x10-4), AR (p = 2.91x10-13), and AD (p = 6.95x10-7). Asthmatic patients with oil palm sensitization have increased risks of wheezing (p = 0.00995), nocturnal cough (p = 0.0122), and exacerbations (p = 0.00139) in the past 12 months. AR patients with oil palm sensitization also have an increased risk of developing moderate-to-severe symptoms (p = 0.00113).

Conclusions

We have identified significant associations of oil palm sensitization with increased risks, exacerbations, and the severity of symptoms of allergic diseases in the tropical Southeast Asian region (Singapore/Malaysia).

A Dietary Pattern for High Estimated Total Fat Amount Is Associated with Enhanced Allergy Sensitization and Atopic Diseases among Singapore/Malaysia Young Chinese Adults

INTRODUCTION

Frequent dietary patterns for fast food diets are suggested to be a risk factor for atopic disease development. Excessive dietary fats in fast foods are postulated to promote low-grade chronic inflammation. However, no studies in Asia have yet to characterize the dietary pattern for high-fat foods with atopic diseases. Thus, this study aims to assess the association between dietary fats with the prevalence of atopic diseases in an allergic cohort.

METHODS

Through an investigator-administered questionnaire that follows the International Study of Asthma and Allergies in Childhood (ISAAC) protocol, we evaluated the eating habits, lifestyle behaviours, sociodemographics, and atopic symptoms, and history among 11,494 young Chinese adults in Singapore and Malaysia. A skin prick test (SPT) for common house dust mites was also conducted to determine the atopic (allergic) status. We identified 1,550 atopic dermatitis (AD), 1,301 allergic asthma (AS), and 3,757 allergic rhinitis (AR) atopic cases. We derived a novel dietary index, Diet Quality based on Total Fat Amount (DQTFA), to examine the association between eating patterns for estimated total fat amount with various atopic outcomes.

RESULTS

There was a preponderance of subjects having positive SPT reaction (69.0%) with the prevalence of AR being the highest (32.7%), then AD (13.5%), and AS (11.3%). Additionally, there is a significantly higher proportion of subjects with an atopy background and atopic diseases consume diets with a high estimated mean fat amount. The adherence to a dietary pattern of the higher estimated total fat amount was shown to be strongly associated with all atopic diseases and exhibited dose-dependent responses in the univariate analysis. These associations remained significant even with the adjustments for age, gender, body mass index, use of alcohol, sedentary lifestyles, and physical activity. A dietary pattern for high-fat amount is more strongly associated with AS (adjusted odds ratio [AOR]: 1.524; 95% confidence interval [CI]: 1.216-1.725; p < 0.001) and AR (AOR: 1.294; 95% CI: 1.107-1.512; p < 0.001) compared to AD (AOR: 1.278; 95% CI: 1.049-1.559; p < 0.05). Finally, it was shown that having either one of the atopic comorbidities was strongly associated with a dietary pattern of high-fat amounts (AOR: 1.360; 95% CI: 1.161-1.594; p < 0.001).

CONCLUSION

Our findings altogether provide initial evidence that the dietary pattern of a diet high in fat amount is associated with an increased risk of atopy and atopic diseases in young Chinese adults in Singapore and Malaysia. Balancing the consumption of dietary fats and changing personal dietary habits by choosing foods of the lower fat amount may reduce the associated odds of atopic diseases.

The ERBB2 Exonic Variant Pro1170Ala Modulates Mitogen-Activated Protein Kinase Signaling Cascades and Associates with Allergic Asthma

INTRODUCTION

Previous studies have indicated the ERBB2 genetic variants in the 17q12 locus might be associated with asthma; however, the functional effects of these variants on asthma risk remain inconclusive. This study aimed to characterize the functional roles of asthma-associated ERBB2 single nucleotide polymorphisms (SNPs) in asthma pathogenesis by performing genetic association and functional analysis studies.

METHODS

This study belongs to a part of an ongoing Singapore/Malaysia cross-sectional genetics and epidemiological study (SMCSGES). Genotype-phenotype associations were assessed by performing a genotyping assay on n = 4,348 ethnic Chinese individuals from the SMCSGES cohort. The phosphorylation levels of receptors and signaling proteins in the MAPK signaling cascades, including ErbB2, EGFR, and ERK1/2, were compared across the genotypes of asthma-associated SNPs through in vitro and ex vivo approaches.

RESULTS

The ERBB2 tag-SNP rs1058808 was significantly associated with allergic asthma, with the allele "G" identified as protective against the disease (adjusted logistic p = 6.56 × 10-9, OR = 0.625, 95% CI: 0.544-0.718). The allele "G" of rs1058808 resulted in a Pro1170Ala mutation that results in lower phosphorylation levels of ErbB2 in HaCat cells (p < 0.001), whereas the overall ERBB2 mRNA expression and the phosphorylation levels of EGFR remained unaffected. In the SMCSGES cohort, individuals carrying the genotype "GG" of rs1058808 had lower phosphorylated ERK1/2 proteins in the MAPK signaling cascade. A lower phosphorylation level of ERK1/2 was also associated with reduced asthma risk.

CONCLUSIONS

The present findings highlighted the involvement of a functional exonic variant of ERBB2 in asthma development via modulating the MAPK signaling cascade.