The Atopic March: Progression from Atopic Dermatitis to Allergic Rhinitis and Asthma

Eosinophil innate immune memory after bacterial skin infection promotes allergic lung inflammation

Microbial exposure at barrier interfaces drives development and balance of the immune system, but the consequences of local infections for systemic immunity and secondary inflammation are unclear. Here, we show that skin exposure to the bacterium Staphylococcus aureus persistently shapes the immune system of mice with specific impact on progenitor and mature bone marrow neutrophil and eosinophil populations. The infection-imposed changes in eosinophils were long-lasting and associated with functional as well as imprinted epigenetic and metabolic changes. Bacterial exposure enhanced cutaneous allergic sensitization and resulted in exacerbated allergen-induced lung inflammation. Functional bone marrow eosinophil reprogramming and pulmonary allergen responses were driven by the alarmin interleukin-33 and the complement cleavage fragment C5a. Our study highlights the systemic impact of skin inflammation and reveals mechanisms of eosinophil innate immune memory and organ cross-talk that modulate systemic responses to allergens.

Methodological Quality and Content of Guidelines on Early Childhood Allergy Prevention: A Systematic Assessment and Content Analysis

Recommendations on Early Childhood Allergy Prevention (ECAP) are found in Clinical Practice Guidelines (CPG) and Food-Based Dietary Guidelines (FBDG). This synthesis of guidelines aims to compare the methodological quality and content of recommendations in CPGs and FBDGs for ECAP. We searched MEDLINE, the FAO directory of FBDGs and other guideline databases, including the Association of the Scientific Medical Societies in Germany (AWMF), the WHO and the Guideline International Networks database on clinical guidelines (GIN) for CPGs and FBDGs about ECAP and child nutrition. Guidelines had to be published from 2010 onwards, target infants or pregnant/breastfeeding women and contain recommendations on primary preventative interventions to decrease the onset of IgE-mediated allergies, including atopic eczema or asthma. We retrieved a sample of 36 guidelines (23 CPGs, 13 FBDGs) and assessed their methodological quality with the Appraisal of Guidelines for Research and Evaluation tool (AGREE) II. On a subset of recommendations, we performed an in-depth analysis by the type of intervention for direction and strength of recommendation and level of evidence. Descriptive analysis was conducted with SPSS 27. CPGs score higher than FBDGs in most AGREE domains (3, 4, 5 and 6). The 36 guidelines contain 287 recommendations on ECAP, with 70 addressing the introduction of complementary foods and common allergens. We found only slight differences between those recommendations in CPGs and FBDGs. FBDGs on ECAP are of lower quality than CPGs. This does not affect their recommendations on the introduction of complementary foods and common allergens but may compromise their trustworthiness.

New generation sequencing: molecular approaches for the detection and monitoring of bioaerosols in an indoor environment: a systematic review

INTRODUCTION

The exposure of occupants to indoor air pollutants has increased in recent decades. The aim of this review is to discuss an overview of new approaches that are used to study fungal aerosols. Thus, this motivation was to compensate the gaps caused by the use of only traditional approaches in the study of fungal exposure.

CONTENT

The search involved various databases such as; Science Direct, PubMed, SAGE, Springer Link, EBCOHOST, MEDLINE, CINAHL, Cochrane library, Web of Science and Wiley Online Library. It was limited to full text research articles that reported the use of non-viable method in assessing bioaerosol, written in English Language, full text publications and published from year 2015-2022.

SUMMARY AND OUTLOOK

A total of 15 articles met the inclusion criteria and was included in this review. The use of next-generation sequencing, which is more commonly referred to as high-throughput sequencing (HTS) or molecular methods in microbial studies is based on the detection of genetic material of organisms present in a given sample. Applying these methods to different environments permitted the identification of the microorganisms present, and a better comprehension of the environmental impacts and ecological roles of microbial communities. Based on the reviewed articles, there is evidence that dust samples harbour a high diversity of human-associated bacteria and fungi. Molecular methods such as next generation sequencing are reliable tools for identifying and tracking the bacterial and fungal diversity in dust samples using 18S metagenomics approach.

Allergy Inhibition Using Naturally Occurring Compounds Targeting Thymic Stromal Lymphopoietin Pathways: a Comprehensive Review

Naturally occurring compounds have widely been applied to treat diverse pharmacological effects, including asthma, allergic diseases, antioxidants, inflammation, antibiotics, and cancer. Recent research has revealed the essential role of the thymic stromal lymphopoietin (TSLP) in regulating inflammatory responses at mucosal barriers and maintaining immune homeostasis. Asthma, inflammation, and chronic obstructive pulmonary disease are allergic disorders in which TSLP plays a significant role. Although TSLP's role in type 2 immune responses has undergone comprehensive investigation, its involvement in inflammatory diseases and cancer has also been found to be expanding. However, investigating how to block the TSLP pathway using natural products has been limited. This paper summarizes the roles of various medicinal plants and their chemical components that effectively inhibit the TSLP pathway. In addition, we also highlight the contributions of several plant-derived compounds to treat allergic diseases via targeting TSLP. This review intends to offer innovative concepts to scientists investigating the use of naturally produced compounds and extracts for the treatment of allergic illnesses.

Drivers of Bronchodilator Use in Bronchiolitis: Analyzing Treatment Trends From Pediatric Emergency Department Practices

OBJECTIVES

This study aims to evaluate patient characteristics associated with bronchodilator (BD) use at various stages of bronchiolitis illness and evaluate corresponding patient outcomes in the emergency department (ED).

METHODS

This retrospective, cross-sectional study involves secondary data analysis from a sample of 932 children ages 3 to 24 months who received a diagnosis of bronchiolitis during an ED visit (1057 cases). Predictor variables included demographics, past medical history, family history, physical findings, medication use, and disposition. Outcomes included BD use for bronchiolitis symptoms in the pre-ED and ED settings, and associated care outcomes in the ED. Predictors of BD use in the ED with statistical significance were incorporated in a predictive multivariable logistic regression model with a training-validation split of 70% to 30%.

RESULTS

Children with prior BD use were significantly more likely than children without such history to receive BD treatment during their current bronchiolitis illness before the ED [odds ratio (OR): 23.7, 95% CI: 14.4-39], in the ED (OR: 2.6, 95% CI: 1.76-3.77), and as a prescription upon discharge from the ED (OR: 3.7, 95% CI: 2.49-5.58). In multivariable regression analyses, older age, parental asthma history, and wheezes and retractions on ED physical examination were significantly associated with BD use in the ED (P<0.05). The area under the curve for the validation model with these variables was 0.826 (95% CI: 0.794-0.858).

CONCLUSIONS

Prior BD use was associated with subsequent use during the current illness, during ED care, and subsequent prescription, forming a cyclical pattern. A perceived bronchospastic phenotype of bronchiolitis may influence clinical practice in ED settings.

Systemic Therapy for Atopic Dermatitis in Children and Adolescents: A US Expert Consensus

Atopic dermatitis (AD) is a chronic, type-2 mediated, inflammatory skin disease characterized by intense pruritus, disruption of skin barrier function, and immune dysregulation. Management strategies for AD are routinely determined based on disease severity. First-line treatment begins with basic skin care and topical anti-inflammatory medication, which is typically sufficient for the management of mild-to-moderate disease. For those patients with moderate-to-severe disease, systemic therapy is often required. This can involve off-label treatment with conventional immunosuppressant medications. However, this approach is limited by a lack of robust clinical trial data and safety concerns that necessitate close monitoring. The emergence of novel targeted biologics and small molecules to treat AD presents an opportunity to optimize AD management and patient outcomes by offering greater efficacy than traditional immunosuppressants and a favorable safety profile. As the treatment landscape shifts, clinicians can benefit from a standardized process of patient assessment and treatment, along with resources to help maintain contemporary knowledge of available therapeutic options. This US-based, expert-led consensus used a modified Delphi process to develop core recommendations for the use of systemic medications for the management of pediatric patients <18 years of age with moderate-to-severe AD.

Epigenetic and biological age acceleration in children with atopic dermatitis

Background

Atopic dermatitis (AD) is a chronic inflammatory skin disease resulting from the complex interplay of genetic and environmental factors, meriting exploration using temporally dynamic biomarkers. DNA methylation-based algorithms have been trained to accurately estimate biological age, and deviation of predicted age from true age (epigenetic age acceleration) has been implicated in several inflammatory diseases, including asthma.

Objective

We sought to determine the role of epigenetic and biological aging, telomere length, and epigenetically inferred abundance of 7 inflammatory biomarkers in AD.

Methods

We performed DNA methylation-based analyses in a pediatric AD cohort (n = 24, mean ± standard deviation [SD] age 2.56 ± 0.28 years) and age-matched healthy subjects (n = 24, age 2.09 [0.15] years) derived from blood using 5 validated algorithms that assess epigenetic age (Horvath, Skin&Blood) and biological age (PhenoAge, GrimAge), telomere length (TelomereLength), and inflammatory biomarker levels.

Results

Epigenetic and biological age, but not telomere length, were accelerated in AD patients for 4 algorithms: Horvath (+0.88 years; 95% confidence interval [CI], 0.33 to 1.4; P = 2.3 × 10-3), Skin&Blood (+0.95 years; 95% CI, 0.67 to 1.2; P = 1.8 × 10-8), PhenoAge (+8.2 years; 95% CI, 3.4 to 13.0; P = 1.3 × 10-3), and GrimAge (+1.8 years 95% CI, 0.22 to 3.3; P = .026). Moreover, patients had increased levels of β2 microglobulin (+47,584.4 ng/mL; P = .029), plasminogen activation inhibitor 1 (+3,432.9 ng/mL; P = 1.1 × 10-5), and cystatin C (+31,691 ng/mL; P = 4.0 × 10-5), while levels of tissue inhibitor metalloproteinase 1 (-370.7 ng/mL; P = 7.5 × 10-4) were decreased compared to healthy subjects.

Conclusion

DNA methylation changes associated with epigenetic and biological aging, and inflammatory proteins appear early in life in pediatric AD and may be relevant clinical biomarkers of pathophysiology.

Oral and topical administration of a geranyl acetophenone attenuates DNCB-induced atopic dermatitis-like skin lesions in BALB/c mice

Atopic dermatitis (AD) is a chronic, allergic inflammatory skin disorder that lacks a definite cure. Using a mouse DNCB-induced AD-like skin lesions model, this study evaluated the potential therapeutic utility of tHGA as an oral and topical treatment for AD. Male BALB/c mice were sensitised and challenged with 1% and 0.5% DNCB on their shaved dorsal skin. Mice in the treatment group were administered tHGA (20, 40, and 80 mg/kg) orally three times per week for 2 weeks, or tHGA (0.2%, 1%, and 5%) topically once daily for 12 days. On day 34, the mice were euthanized, and blood and dorsal skin samples were obtained for analysis. All doses of orally and topically administered tHGA significantly improved scratching, epidermal thickness, blood eosinophilia and mast cell infiltration. There was a minor discrepancy between the two routes of administration, with orally treated tHGA showing significant reductions in Scoring of Atopic Dermatitis (SCORAD), tissue eosinophil infiltration, serum IgE and skin IL-4 levels with treatment of 40 and 80 mg/kg tHGA, whereas topically applied tHGA showed significant reductions in all dosages. These findings suggest that tHGA exhibited therapeutic potential for AD as both oral and topical treatment ameliorates AD-like symptoms in the murine model.

Atopic diseases-Diagnostics, mechanisms, and exposures

Epidemiological data suggest that atopic diseases begin in early life and that most cases present clinically during early childhood. The diseases are highly prevalent and increase as communities adopt western lifestyles. Disentangling the pathophysiological mechanisms leading to disease debut is necessary to identify beneficial/harmful exposures so that successful prevention and treatment can be generated. The objective of this review is to explore the definition of atopy and mechanisms of atopic diseases, and to investigate the importance of environmental factors in early life, prior to disease development. First, the distribution of sIgE levels in children is investigated, as this is one of the main criteria for the definition of atopy. Thereafter, it is explored how studies of parental atopic status, sensitization patterns, and early debut and severity of atopic dermatitis have substantiated the theory of an early-life window of opportunity for intervention that precedes the development of atopic diseases in childhood. Then, it is examined whether early-life exposures such as breastfeeding, dogs, cats, and house dust mites in the home perinatally constitute important influencers in this crucial time of life. Finally, it is discussed how these findings could be validated in randomized controlled trials, which might prepare the ground for improved diagnostics and prevention strategies to mitigate the current atopic pandemic.

Role of antioxidants supplementation in the treatment of atopic dermatitis: a critical narrative review

Atopic dermatitis (AD) is a chronic inflammatory skin disease characterized by itching, epidermal barrier dysfunction, and an unbalanced inflammatory reaction. AD pathophysiology involves a dysregulated immune response driven by T helper-2 cells. Many factors, including reactive oxygen species (ROS), are involved in AD pathogenesis by causing cellular damage and inflammation resulting in skin barrier dysfunction. This narrative review aims to provide a comprehensive overview of the role of natural molecules and antioxidant compounds, highlighting their potential therapeutic value in AD prevention and management. They include vitamin D, vitamin E, pyridoxine, Vitamin C, carotenoids, and melatonin. Some studies report a statistically significant association between antioxidant levels and improvement in AD, however, there are conflicting results in which antioxidant supplementation, especially Vitamin D, did not result in improvement in AD. Therefore, the clinical efficacy of these dietary nutritional factors in the treatment of AD needs to be further evaluated in clinical trials. Meanwhile, antioxidants can be incorporated into the management of AD patients in a personalized manner, tailored to the severity of the disease, comorbidities, and individual needs.

Ethnic and Racial Disparities in Clinical Manifestations of Atopic Dermatitis

Atopic dermatitis is a heterogenous inflammatory skin illness that may last for long time and affect people of different racial and ethnic backgrounds. The condition primarily appears in infants and young children. There are people living with atopic dermatitis in every country and every ethnic group, although the frequency of the disease varies greatly. Due to the varied clinical presentations that atopic dermatitis can have, it can be challenging to characterize and diagnose the disease, particularly in adults. Nevertheless, there exists a dearth of information pertaining to the various presentations of atopic dermatitis among individuals from diverse racial and cultural groups. This critical review article offers a succinct and comprehensive overview of the current findings on the epidemiology of atopic dermatitis with regards to ethnic and racial disparities. The findings hold potential significance in advancing the development of targeted treatments for personalized medicine approaches and enhancing the quality of life for patients with atopy.

Novel insights into the immune response to bacterial T cell superantigens

Bacterial T cell superantigens (SAgs) are a family of microbial exotoxins that function to activate large numbers of T cells simultaneously. SAgs activate T cells by direct binding and crosslinking of the lateral regions of MHC class II molecules on antigen-presenting cells with T cell receptors (TCRs) on T cells; these interactions alter the normal TCR-peptide-MHC class II architecture to activate T cells in a manner that is independent of the antigen specificity of the TCR. SAgs have well-recognized, central roles in human diseases such as toxic shock syndrome and scarlet fever through their quantitative effects on the T cell response; in addition, numerous other consequences of SAg-driven T cell activation are now being recognized, including direct roles in the pathogenesis of endocarditis, bloodstream infections, skin disease and pharyngitis. In this Review, we summarize the expanding family of bacterial SAgs and how these toxins can engage highly diverse adaptive immune receptors. We highlight recent findings regarding how SAg-driven manipulation of the adaptive immune response may operate in multiple human diseases, as well as contributing to the biology and life cycle of SAg-producing bacterial pathogens.

Evaluation of Childhood Allergy Risk Among Pregnant Women in a Tertiary Care Hospital in Thailand

OBJECTIVES

This study aims to evaluate the prevalence of pregnant women whose children are at higher risk for childhood allergies and to assess knowledge of risk assessment and prevention strategies.

METHODS

A cross-sectional study was conducted on 310 pregnant women in an antenatal care clinic at a tertiary care hospital in Thailand. In addition to baseline demographic and obstetric characteristics, all participating pregnant women were asked to complete a questionnaire regarding risk evaluation and knowledge of childhood allergies on various topics. A childhood allergy risk assessment was evaluated based on the history of allergy disease in immediate family members. The questionnaire on knowledge was derived from a guideline issued by the Allergy, Asthma, and Immunology Association of Thailand, with possible scores of 0-30.

RESULTS

The mean maternal age was 30.6 years, and 139 (44.8%) were nulliparous. Overall, 86 couples (27.7%) were at high risk for childhood allergies. The mean total knowledge score was 15.2 out of 30, and only 24 women (7.7%) had an overall score of >20, and 40 women (12.9%) had an overall score of ≤10. The mean knowledge score for almost every subtopic was less than half of the possible points, except for the risk reduction strategies during pregnancy. Comparisons between those with higher and lower scores (≥16 vs. ≤15 points) showed that women with higher knowledge scores were significantly more likely to have had a previous child with an allergy (p=0.010).

CONCLUSION

The prevalence of pregnant women whose children were at higher risk for childhood allergies was 27.7% (86 of 310 couples). The women had limited knowledge of childhood allergies with regard to risk assessment, risk reduction strategies, and various interventions. The only factor associated with a higher knowledge score was having a previous child with an allergy.

Reported food-related symptoms and food allergen sensitization in a selected adult population in Hyderabad, India: A hospital-based survey

Background

Research on reported food-related triggers of atopic disease in South Asian adults is lacking despite the region's large population and the global significance of allergic diseases.

Objectives

The study aimed to identify prevalent local food items and assess allergic sensitization rates to potential trigger foods for atopic diseases via skin prick and specific IgE testing.

Methods

The study began with a pilot survey of 100 subjects recruited from 4 hospitals in Hyderabad, India, focusing on foods perceived to relate to asthma, allergic rhinitis, atopic dermatitis, urticaria, and gastrointestinal allergic symptoms. A subsequent main study evaluated 2010 participants, 1754 of whom were diagnosed with an aforementioned atopic disease and who reported allergic symptoms related to any of 77 foods identified in the pilot study. Ultimately 1622 patients who consented to skin prick and specific IgE testing and who reported at least 1 food item triggering allergic diseases were included in the final analysis.

Results

Among 1622 patients (average age, 42.6 ± 12.9 years; 55.5% male), asthma was the most commonly diagnosed atopic disease (26.4%), with itching and rash being frequently reported symptoms (22.7%). Notably, 94.9% of patients had total serum IgE > 144 kU/L. Chickpea, cabbage, eggplant, walnut, cumin, and betel leaf were the most commonly reported trigger foods.

Conclusion

In this sample of South Indian adults diagnosed with allergic disease, reported food triggers were most commonly local dietary staples, while reported reactions to priority allergens like peanut and sesame were conspicuously absent. Observed concordance between patient-reported food triggers and sensitization to reported food triggers was low, highlighting the need for improved clinical evaluation of suspected triggers.

Cracking the code: unveiling the nexus between atopic dermatitis and addictive behavior: a cross-sectional exploration of risk factors

Atopic dermatitis (AD) stands as a prevalent chronic inflammatory skin disorder with a global reach. Beyond its cutaneous manifestations, AD is accompanied by comorbidities and psychological issues, significantly compromising the overall quality of life for individuals who suffer from AD. Previous research has evidenced a heightened prevalence of addictive disorders among dermatological patients when compared to the general population. Considering these findings, this study endeavors to examine the prevalence of addictive disorders among AD patients and, furthermore, to discern potential risk factors associated with this comorbidity. Therefore, a cross-sectional study was conducted involving patients with AD diagnosed by dermatologists within a large university hospital in Munich, South Germany, between January 2016 and December 2019. Patients received an anonymous paper-based questionnaire comprising standardized and reliable assessment tools concerning disease severity, quality of life, sexual dysfunction, well-being, and anxiety disorder as well as screening tools for various addictive disorders (compulsive internet use, drug abuse, pathological alcohol consumption, and smoking). Data were analyzed descriptively, and a multivariate logistic regression model was conducted. A total of 208 patients participated in the study, comprising 38% males and 62% females with a mean age of 44.8 ± standard deviation:17.9 years. Females showed a higher mean POEM (Patient-Oriented Eczema Measure) score compared to males (female 14.6 ± 7.8; male 12.5 ± 7.7), as well as a higher DLQI (Dermatology Life Quality Index) (female 8.5 ± 6; male 6.5 ± 6.5). Positive addictions were found in 14.9% for daily smoking, 15.4% for critical alcohol consumption, 16.8% for compulsive internet use, and 5.8% for drug abuse. Younger patients were more likely to be affected by one or multiple addictions than older patients. Patients with at least one addiction showed significantly impaired well-being and increased severe anxiety symptoms. Given the notable prevalence of addictive disorders among individuals with AD, it could be useful to implement systematic screening for such conditions as part of patient-centered care, especially focusing on young AD patients or those displaying concurrent indications of depression or anxiety.

Unraveling the skin; a comprehensive review of atopic dermatitis, current understanding, and approaches

Atopic dermatitis, also known as atopic eczema, is a chronic inflammatory skin disease characterized by red pruritic skin lesions, xerosis, ichthyosis, and skin pain. Among the social impacts of atopic dermatitis are difficulties and detachment in relationships and social stigmatization. Additionally, atopic dermatitis is known to cause sleep disturbance, anxiety, hyperactivity, and depression. Although the pathological process behind atopic dermatitis is not fully known, it appears to be a combination of epidermal barrier dysfunction and immune dysregulation. Skin is the largest organ of the human body which acts as a mechanical barrier to toxins and UV light and a natural barrier against water loss. Both functions face significant challenges due to atopic dermatitis. The list of factors that can potentially trigger or contribute to atopic dermatitis is extensive, ranging from genetic factors, family history, dietary choices, immune triggers, and environmental factors. Consequently, prevention, early clinical diagnosis, and effective treatment may be the only resolutions to combat this burdensome disease. Ensuring safe and targeted drug delivery to the skin layers, without reaching the systemic circulation is a promising option raised by nano-delivery systems in dermatology. In this review, we explored the current understanding and approaches of atopic dermatitis and outlined a range of the most recent therapeutics and dosage forms brought by nanotechnology. This review was conducted using PubMed, Google Scholar, and ScienceDirect databases.

Incidence and prevalence of keratoconus in Taiwan during 2000-2018 and their association with the use of corneal topography and tomography

PURPOSE

The aim of this study was to determine the age- and sex-specific incidence and prevalence of keratoconus (KC) in Taiwan and explore their association with the use of computerized corneal topography and tomography (TG).

DESIGN

This nationwide retrospective study included the Taiwanese population (N = 27,540,859) from the National Health Insurance Research Database (NHIRD) between 2000 and 2018.

METHOD

We estimated the incidence of KC by identifying patients with newly diagnosed KC and estimated its prevalence by identifying patients who had the ICD9-CM code 371.6 or ICD-10-CM code H18.609 twice or more in NHIRD during 2000-2018.

RESULTS

The incidence of KC in Taiwan during 2000-2018 was 7075, with the incidence rate being 1.56 (95% confidence interval [CI]: 1.53-1.60) per 100,000 person-years. The prevalence of KC was 4.29 (95% CI: 4.23-4.35) per 100,000 person-years. The KC incidence rate peaked in patients aged 21-25 (6.40 in males and 3.19 in females). The overall incidence rates in males and females were 2.01 and 1.35, respectively (incidence rate ratio: 1.46), indicating that KC had a significant male predisposition. Moreover, we noted a linear correlation (R2 = 0.7488) between the proportion of the use of TG and the incidence of KC.

CONCLUSION

Estimates of nationwide population-based incidence and prevalence can contribute to a better understanding of the risk of ethnic groups and geographic locations in KC, and the trend can help physicians improve the general vision health of the population.

A cross talk between microbial metabolites and host immunity: Its relevance for allergic diseases

BACKGROUND

Allergic diseases, including respiratory and food allergies, as well as allergic skin conditions have surged in prevalence in recent decades. In allergic diseases, the gut microbiome is dysbiotic, with reduced diversity of beneficial bacteria and increased abundance of potential pathogens. Research findings suggest that the microbiome, which is highly influenced by environmental and dietary factors, plays a central role in the development, progression, and severity of allergic diseases. The microbiome generates metabolites, which can regulate many of the host's cellular metabolic processes and host immune responses.

AIMS AND METHODS

Our goal is to provide a narrative and comprehensive literature review of the mechanisms through which microbial metabolites regulate host immune function and immune metabolism both in homeostasis and in the context of allergic diseases.

RESULTS AND DISCUSSION

We describe key microbial metabolites such as short-chain fatty acids, amino acids, bile acids and polyamines, elucidating their mechanisms of action, cellular targets and their roles in regulating metabolism within innate and adaptive immune cells. Furthermore, we characterize the role of bacterial metabolites in the pathogenesis of allergic diseases including allergic asthma, atopic dermatitis and food allergy.

CONCLUSION

Future research efforts should focus on investigating the physiological functions of microbiota-derived metabolites to help develop new diagnostic and therapeutic interventions for allergic diseases.

Defining and Measuring the Scope of Atopic Dermatitis

Atopic dermatitis (AD) has no definitive diagnostic test and has a large range of phenotypes, making it a difficult disease to assess and define. However, an agreed-upon definition of AD is important for clinical trials, population-based studies, and clinical practice. Several diagnostic criteria systems have been proposed to fill these needs, with none considered the gold standard. To further aid in standardized assessment of AD patients, numerous disease severity and quality-of-life measurement tools have been proposed. There is similarly no gold standard and efforts are ongoing to develop a single consensus scale. Finally, assessment of AD-associated comorbidities, including allergic/immunologic conditions, psychiatric disorders, and metabolic/cardiac conditions, is important when evaluating this patient population.

Resveratrol modulates the Nrf2/NF-κB pathway and inhibits TSLP-mediated atopic march

BACKGROUND

Resveratrol has been found to have anti-inflammatory and anti-allergic properties. The effects of resveratrol on thymic stromal lymphopoietin (TSLP)-mediated atopic march remain unclear.

PURPOSE

To explore the potential role of resveratrol in TSLP-mediated atopic march.

METHODS

The atopic march mouse model was established by topical application of MC903 (a vitamin D3 analog). Following the treatment with resveratrol, airway resistance in mice was discovered by pulmonary function apparatus, and the number of total cells, neutrophils, and eosinophils in bronchoalveolar lavage fluid was counted. The histopathological features of pulmonary and ear skin tissues, inflammation, and cell infiltration were determined by hematoxylin and eosin staining. The messenger RNA (mRNA) levels of TSLP, immunoglobulin E, interleukin (IL)-4, IL-5, and IL-13 were measured by real-time quantitative polymerase chain reaction. The protein expression of nuclear factor kappa B (NF-κB)/nuclear factor erythroid 2-related factor 2 (Nrf2) signaling-associated molecules (p-p65, p65, p-I kappa B kinase alpha (IκBα), IκBα, Nrf2, and TSLP) in lung and ear skin tissues were assessed by Western blot analysis.

RESULTS

Resveratrol attenuated airway resistance and infiltration of total cells, eosinophils, and neutrophils in both lung and ear skin tissues. Resveratrol ameliorates serum inflammatory markers in allergic mice. Moreover, the phosphorylation levels of NF-κB pathway-related proteins were significantly reduced by administration of resveratrol in allergic lung and ear skin tissues. Similarly, the protein expression of TSLP in both lung and ear skin tissues was reduced by resveratrol, and Nrf2, a protector molecule, was increased with resveratrol treatment.

CONCLUSION

Resveratrol attenuates TSLP-reduced atopic march through ameliorating inflammation and cell infiltration in pulmonary and ear skin tissues by inhibiting the abnormal activation of NF-κB signaling pathway.

Association between a maternal vegetarian diet during pregnancy and the occurrence of atopic dermatitis in children

BACKGROUND

Atopic dermatitis (AD) is rising globally, with genetics and environmental factors both playing crucial roles. Dietary habits during pregnancy are linked to children's allergic disease risk. However, limited studies have explored the association between maternal vegetarian diets during pregnancy and child AD. Therefore, this study aimed to examine the relationship between maternal vegetarian diets during pregnancy and the occurrence of AD in children.

METHODS

In this study, the Taiwan Birth Cohort Study (TBCS) database was used, comprising a representative national birth cohort of infants born in Taiwan in 2005. Of 24,200 mother-child pairs in the database, 20,172 completed face-to-face interviews at 6 and 18 months. Employing a 1:10 matching strategy based on maternal age, education level, and child sex, 408 mothers who followed a vegetarian diet during pregnancy were matched with 4080 nonvegetarian mothers. This resulted in a final dataset of 4488 subjects. Logistic regression was used to explore the association between maternal vegetarian diets during pregnancy and the occurrence of AD in children.

RESULTS

Among the TBCS participants, there were 292 (1.8%) mothers who adhered to lacto-ovo vegetarianism and 116 (0.7%) mothers who adhered to veganism, totaling 408 (2.4%) vegetarians during pregnancy. Compared to children of nonvegetarian mothers, children of mothers who followed a vegetarian diet during pregnancy showed a lower risk of developing AD before 18 months of age (OR = 0.65, 95% CI = 0.45-0.93, p = 0.018).

CONCLUSION

This study suggests that a vegetarian diet during pregnancy may lower the risk of AD in children. It is essential to carry out long-term follow-up to fully understand the impact of a mother's diet on allergic conditions.

Modeling immunity in microphysiological systems

There is a need for better predictive models of the human immune system to evaluate safety and efficacy of immunomodulatory drugs and biologics for successful product development and regulatory approvals. Current in vitro models, which are often tested in two-dimensional (2D) tissue culture polystyrene, and preclinical animal models fail to fully recapitulate the function and physiology of the human immune system. Microphysiological systems (MPSs) that can model key microenvironment cues of the human immune system, as well as of specific organs and tissues, may be able to recapitulate specific features of the in vivo inflammatory response. This minireview provides an overview of MPS for modeling lymphatic tissues, immunity at tissue interfaces, inflammatory diseases, and the inflammatory tumor microenvironment in vitro and ex vivo. Broadly, these systems have utility in modeling how certain immunotherapies function in vivo, how dysfunctional immune responses can propagate diseases, and how our immune system can combat pathogens.

S. aureus virulence factors decrease epithelial barrier function and increase susceptibility to viral infection

Individuals with atopic dermatitis (AD) are highly colonized by Staphylococcus aureus and are more susceptible to severe viral complications. We hypothesized that S. aureus secreted virulence factors may alter keratinocyte biology to enhance viral susceptibility through disruption of the skin barrier, impaired keratinocyte differentiation, and/or inflammation. To address this hypothesis, human keratinocytes were exposed to conditioned media from multiple S. aureus strains that vary in virulence factor production (USA300, HG003, and RN4220) or select purified virulence factors. We have identified the S. aureus enterotoxin-like superantigen SElQ, as a virulence factor of interest, since it is highly produced by USA300 and was detected on the skin of 53% of AD subjects (n = 72) in a study conducted by our group. Treatment with USA300 conditioned media or purified SElQ resulted in a significant increase in keratinocyte susceptibility to infection with vaccinia virus, and also significantly decreased barrier function. Importantly, we have previously demonstrated that keratinocyte differentiation influences susceptibility to viral infection, and our qPCR observations indicated that USA300 S. aureus and SElQ alter differentiation in keratinocytes. CRISPR/Cas9 was used to knock out CD40, a potential enterotoxin receptor on epithelial cells. We found that CD40 expression on keratinocytes was not completely necessary for SElQ-mediated responses, as measured by proinflammatory cytokine expression and barrier function. Together, these findings support that select S. aureus virulence factors, particularly SElQ, enhance the susceptibility of epidermal cells to viral infection, which may contribute to the increased cutaneous infections observed in individuals with AD. IMPORTANCE Staphylococcus aureus skin colonization and infection are frequently observed in individuals with atopic dermatitis. Many S. aureus strains belong to the clonal group USA300, and these strains produce superantigens including the staphylococcal enterotoxin-like Q (SElQ). Our studies highlight that SElQ may play a key role by altering keratinocyte differentiation and reducing barrier function; collectively, this may explain the AD-specific enhanced infection risk to cutaneous viruses. It is unclear what receptor mediates SElQ's effects on keratinocytes. We have shown that one putative surface receptor, CD40, was not critical for its effects on proinflammatory cytokine production or barrier function.

Variation of asthma characteristics with atopic march, gastroesophageal reflux, and ENT pathologies

BACKGROUND

Asthma is a significant cause of morbidity and mortality in the pediatric population. Atopic dermatitis (AD) is often the first step in the atopic march leading to the development of asthma, allergic rhinitis, and food allergies in the future.

OBJECTIVE

This study aimed to evaluate the severity differences between asthmatic children with and without atopic march in addition to characteristics of asthmatic patients with GER and ear-nose-and-throat (ENT) pathologies.

METHODS

A total of 616 pediatric asthmatic patients were enrolled. The study subjects were divided into two groups. Group A included asthmatic children with a history of AD. Group B had asthmatic children without a history of AD. Multiple factors were studied, including sex, race/ethnicity, family history of atopy, asthma severity, allergic rhinitis, food allergies, smoke exposure, ear-nose-and-throat (ENT) pathologies, gastroesophageal reflux (GER), frequency of systemic steroid use, and hospital admission rates.

RESULTS

Our results revealed that patients with atopic march are at risk of developing a higher severity of asthma, resulting in increased morbidity. In contrast, asthmatic patients without atopic march had a milder asthma severity, less need for steroids, and fewer hospital admissions. A higher prevalence of ENT pathologies and/or GER existed among asthmatic children without atopic march.

CONCLUSION

Our findings suggest that patients with atopic march should be expected to exhibit a more severe phenotype of asthma with increased asthma morbidity. Asthmatic patients without atopic march had a milder asthma phenotype, less need for steroids, and fewer hospital admissions. A higher prevalence of ENT pathologies and/or GER existed among asthmatic children without atopic march.

Association between parental autoimmune disease and childhood atopic dermatitis varied by sex: a nationwide case-control study

Atopic dermatitis (AD) is a common inflammatory skin disorder induced by dysfunction of immune suppression sharing similar pathogenesis to autoimmune diseases. To explore the association between autoimmune diseases and AD in children, we linked the birth data from National Birth Registry with National Health Insurance Research Database. There were 1,174,941 children obtained from 2006 to 2012 birth cohort. A total of 312,329 children diagnosed with AD before 5 years old were compared to 862,612 children without AD in the control group. Conditional logistic regression was utilized to calculate adjusted odds ratio (OR) and Bonferroni-corrected confidence interval (CI) for overall significance level of 0.05. In 2006-2012 birth cohort, the prevalence rate of AD was 26.6% (95% CI 26.5, 26.7) before 5 years of age. Having parental autoimmune disease (including rheumatoid arthritis, systemic lupus erythematosus, Sjogren's syndrome, ankylosing spondylitis, and psoriasis) was associated with a significant higher risk of children AD development. The other associated factors were maternal obstetric complications (including gestational diabetes mellitus and cervical incompetence), parental systemic diseases (including anemia, hypertension, diabetes mellitus, chronic obstructive pulmonary disease, hyperthyroidism, and obstructive sleep apnea), and parental allergic disease (including asthma and AD). The subgroup analysis showed similar results between children's sexes. Moreover, maternal autoimmune disease had higher impact on the risk of developing AD in the child compared with paternal autoimmune disease. In conclusion, parental autoimmune diseases were found to be related to their children's AD before 5 years old.

Type 2 chronic inflammatory diseases: targets, therapies and unmet needs

Over the past two decades, significant progress in understanding of the pathogenesis of type 2 chronic inflammatory diseases has enabled the identification of compounds for more than 20 novel targets, which are approved or at various stages of development, finally facilitating a more targeted approach for the treatment of these disorders. Most of these newly identified pathogenic drivers of type 2 inflammation and their corresponding treatments are related to mast cells, eosinophils, T cells, B cells, epithelial cells and sensory nerves. Epithelial barrier defects and dysbiotic microbiomes represent exciting future drug targets for chronic type 2 inflammatory conditions. Here, we review common targets, current treatments and emerging therapies for the treatment of five major type 2 chronic inflammatory diseases - atopic dermatitis, chronic prurigo, chronic urticaria, asthma and chronic rhinosinusitis with nasal polyps - with a high need for targeted therapies. Unmet needs and future directions in the field are discussed.

Immunologic, genetic, and ecological interplay of factors involved in allergic diseases

An allergic or type I hypersensitivity reaction involves a misdirected immune overreaction to innocuous environmental and dietary antigens called allergens. The genetic predisposition to allergic disease, referred to as atopy, can be expressed as a variety of manifestations-e.g., allergic rhinitis, allergic conjunctivitis, atopic dermatitis, allergic asthma, anaphylaxis. Globally, allergic diseases are one the most common types of chronic conditions. Several factors have been identified to contribute to the pathogenesis and progression of the disease, leading to distinctively variable clinical symptoms. The factors which can attenuate or exacerbate allergic reactions can range from genetic heterozygosity, the prominence of various comorbid infections, and other factors such as pollution, climate, and interactions with other organisms and organism-derived products, and the surrounding environment. As a result, the effective prevention and control of allergies remains to be one of the most prominent public health problems. Therefore, to contextualize the current knowledge about allergic reactions, this review paper attempts to synthesize different aspects of an allergic response to describe its significance in the global health scheme. Specifically, the review shall characterize the biomolecular mechanisms of the pathophysiology of the disease based on underlying disease theories and current findings on ecologic interactions and describe prevention and control strategies being utilized. An integrated perspective that considers the underlying genetic, immunologic, and ecologic aspects of the disease would enable the development of more effective and targeted diagnostic tools and therapeutic strategies for the management and control of allergic diseases.

Disease modification in inflammatory skin disorders: opportunities and challenges

Progress in understanding of the mechanisms underlying chronic inflammatory skin disorders, such as atopic dermatitis and psoriasis vulgaris, has led to new treatment options with the primary goal of alleviating symptoms. In addition, this knowledge has the potential to inform on new strategies aimed at inducing deep and therapy-free remission, that is, disease modification, potentially impacting on associated comorbidities. However, to reach this goal, key areas require further exploration, including the definitions of disease modification and disease activity index, further understanding of disease mechanisms and systemic spillover effects, potential windows of opportunity, biomarkers for patient stratification and successful intervention, as well as appropriate study design. This Perspective article assesses the opportunities and challenges in the discovery and development of disease-modifying therapies for chronic inflammatory skin disorders.

Ovol1/2 loss-induced epidermal defects elicit skin immune activation and alter global metabolism

Skin epidermis constitutes the outer permeability barrier that protects the body from dehydration, heat loss, and myriad external assaults. Mechanisms that maintain barrier integrity in constantly challenged adult skin and how epidermal dysregulation shapes the local immune microenvironment and whole-body metabolism remain poorly understood. Here, we demonstrate that inducible and simultaneous ablation of transcription factor-encoding Ovol1 and Ovol2 in adult epidermis results in barrier dysregulation through impacting epithelial-mesenchymal plasticity and inflammatory gene expression. We find that aberrant skin immune activation then ensues, featuring Langerhans cell mobilization and T cell responses, and leading to elevated levels of secreted inflammatory factors in circulation. Finally, we identify failure to gain body weight and accumulate body fat as long-term consequences of epidermal-specific Ovol1/2 loss and show that these global metabolic changes along with the skin barrier/immune defects are partially rescued by immunosuppressant dexamethasone. Collectively, our study reveals key regulators of adult barrier maintenance and suggests a causal connection between epidermal dysregulation and whole-body metabolism that is in part mediated through aberrant immune activation.

Advanced In Vitro Three-Dimensional Skin Models of Atopic Dermatitis

Atopic dermatitis (AD) is one of the most prevalent inflammatory skin diseases that is characterized by eczematous rashes, intense itching, dry skin, and sensitive skin. Although AD significantly impacts the quality of life and the number of patients keeps increasing, its pathological mechanism is still unknown because of its complexity. The importance of developing new in vitro three-dimensional (3D) models has been underlined in order to understand the mechanisms for the development of therapeutics since the limitations of 2D models or animal models have been repeatedly reported. Thus, the new in vitro AD models should not only be created in 3D structure, but also reflect the pathological characteristics of AD, which are known to be associated with Th2-mediated inflammatory responses, epidermal barrier disruption, increased dermal T-cell infiltration, filaggrin down-regulation, or microbial imbalance. In this review, we introduce various types of in vitro skin models including 3D culture methods, skin-on-a-chips, and skin organoids, as well as their applications to AD modeling for drug screening and mechanistic studies.

National situation, trends, and predictions of disease burden of atopic dermatitis in Chinese children and adolescents

Background

Atopic dermatitis (AD) is an important global health problem affecting children and adolescents and detailed national information of disease burden in China is lacking. We aimed to evaluate the national disease burden of AD in Chinese children and adolescent, to provide the temporal trends over the past 30 years and to predict the burden for the next 10 years.

Methods

The data of AD in China, including incidence, prevalence, and DALY, and population data were obtained from the Global Burden of Disease Study 2019 (GBD study 2019), which were estimated using the DisMod-MR 2.1. We analyzed the three measures by age and sex; the age groups were <5 years, 5-9 years, 10-14 years, and 15-19 years. The joinpoint regression analyses was conducted to assess the temporal trends from 1990 to 2019. The Bayesian age-period cohort (BAPC) model was used to predict measures from 2020 to 2030.

Results

In 2019, the highest incidence case and rate were observed in <5 years group; for prevalence and disability adjusted life year (DALY), the groups of <5 years and 5-9 years showed similar higher levels and the groups of 10-14 years and 15-19 years had similar relatively lower levels. Overall, the male-to-female ratios were >1 in <5 years group and <1 in 10-14 and 15-19 age groups. The trend analyses found an overall trend of decrease in cases of the three measures; in recent about 3 years, slight increase trends were shown in cases and rates of the three measures in <5 years group. The prediction analyses found a slight decreasing trend for cases of these measures and a slight increasing trend for rates of these measures in the <5 years group in the next 10 years; the 5-9 years group was predicted to increase slightly in rates of the three measures.

Conclusion

In conclusion, the groups of <5 years and 5-9 years are two important populations that need targeted measures to reduce disease burden of AD in China. Regarding sex disparity, we should pay more attention to males in <5 years group and to females in 10-19 years group.

Birth order, sibship size, and risk of atopic dermatitis, food allergy, and atopy: A systematic review and meta-analysis

BACKGROUND

Atopic dermatitis and food allergy are two frequently concomitant manifestations of the presence of atopy. A substantial number of studies have been published on the association of birth order and sibship size (number of siblings) with atopic dermatitis, food allergy, and atopy. The present work is the first systematic synthesis of the existing literature on this topic.

METHODS

Fifteen databases were searched. Screening, data extraction, and quality assessment were performed by independent pairs. Comparable numerical data were statistically synthesized using random-effects robust variance estimation.

RESULTS

In total, 114 studies were included out of 8819 papers obtained from database searches. Birth order ≥2 versus 1 was associated with lower risk of ever atopic dermatitis (pooled risk ratio [RR] 0.91, 95% CI 0.84-0.98), current food allergy (RR 0.77, 95% CI 0.66-0.90), and positive skin prick test (SPT) to common aeroallergens (RR 0.86, 95% CI 0.77-0.97). Sibship size ≥2 versus 1 was associated with decreased risk of current atopic dermatitis (RR 0.90, 95% CI 0.83-0.98), ever atopic dermatitis (RR 0.92, 95% CI 0.86-0.97), and positive SPT to common aeroallergens (RR 0.88, 95% CI 0.83-0.92). No putative associations were seen regarding atopy assessed through allergen-specific immunoglobulin E with common allergens.

CONCLUSION

The presence of siblings and being second-born or later may decrease the lifetime risk of atopic dermatitis and food allergy, albeit marginally. Similar association was seen with SPT sensitization. However, significant protection was not found for IgE sensitization.

Homeostatic activation of aryl hydrocarbon receptor by dietary ligands dampens cutaneous allergic responses by controlling Langerhans cells migration

Dietary compounds can affect the development of inflammatory responses at distant sites. However, the mechanisms involved remain incompletely understood. Here, we addressed the influence on allergic responses of dietary agonists of aryl hydrocarbon receptor (AhR). In cutaneous papain-induced allergy, we found that lack of dietary AhR ligands exacerbates allergic responses. This phenomenon was tissue-specific as airway allergy was unaffected by the diet. In addition, lack of dietary AhR ligands worsened asthma-like allergy in a model of 'atopic march.' Mice deprived of dietary AhR ligands displayed impaired Langerhans cell migration, leading to exaggerated T cell responses. Mechanistically, dietary AhR ligands regulated the inflammatory profile of epidermal cells, without affecting barrier function. In particular, we evidenced TGF-β hyperproduction in the skin of mice deprived of dietary AhR ligands, explaining Langerhans cell retention. Our work identifies an essential role for homeostatic activation of AhR by dietary ligands in the dampening of cutaneous allergic responses and uncovers the importance of the gut-skin axis in the development of allergic diseases.

Butyrate inhibits Staphylococcus aureus-aggravated dermal IL-33 expression and skin inflammation through histone deacetylase inhibition

Atopic dermatitis (AD) is an inflammatory skin disease caused by the disruption of skin barrier, and is dominated by the type 2 immune responses. Patients with AD have a high risk of developing Staphylococcus aureus infection. Interleukin-33 (IL-33), an alarmin, has been implicated in the pathophysiology of AD development. Butyrate, a short chain fatty acid known to be produced from the fermentation of glycerol by the commensal skin bacterium, Staphylococcus epidermidis, has been reported to possess antimicrobial and anti-inflammatory properties that suppress inflammatory dermatoses. However, little is known about the effects of butyrate on dermal IL-33 expression and associated immune response in S. aureus-aggravated skin inflammation in the context of AD. To decipher the underlying mechanism, we established an AD-like mouse model with epidermal barrier disruption by delipidizing the dorsal skin to induce AD-like pathophysiology, followed by the epicutaneous application of S. aureus and butyrate. We discovered that S. aureus infection exacerbated IL-33 release from keratinocytes and aggravated dermal leukocyte infiltration and IL-13 expression. Moreover, we showed that butyrate could attenuate S. aureus-aggravated skin inflammation with decreased IL-33, IL-13, and leukocyte infiltration in the skin. Mechanistically, we demonstrated that butyrate suppressed IL-33 expression and ameliorated skin inflammation through histone deacetylase 3 (HDAC3) inhibition. Overall, our findings revealed the potential positive effect of butyrate in controlling inflammatory skin conditions in AD aggravated by S. aureus infection.

Clinical and experimental treatment of allergic asthma with an emphasis on allergen immunotherapy and its mechanisms

Allergen immunotherapy (AIT) is currently the only form of treatment that modifies allergic asthma. Pharmacotherapy alone seeks to control the symptoms of allergic asthma, allergic rhinitis, and other atopic conditions. In contrast, AIT can induce long-term physiological modifications through the immune system. AIT enables individuals to live improved lives many years after treatment ends, where they are desensitized to the allergen(s) used or no longer have significant allergic reactions upon allergen provocation. The leading forms of treatment with AIT involve injections of allergen extracts with increasing doses via the subcutaneous route or drops/tablets via the sublingual route for several years. Since the initial attempts at this treatment as early as 1911 by Leonard Noon, the mechanisms by which AIT operates remain unclear. This literature-based review provides the primary care practitioner with a current understanding of the mechanisms of AIT, including its treatment safety, protocols, and long-term efficacy. The primary mechanisms underlying AIT include changes in immunoglobulin classes (IgA, IgE, and IgG), immunosuppressive regulatory T-cell induction, helper T cell type 2 to helper T cell type 1 cell/cytokine profile shifts, decreased early-phase reaction activity and mediators, and increased production of IL-10, IL-35, TGF-β, and IFN-γ. Using the databases PubMed and Embase, a selective literature search was conducted searching for English, full-text, reviews published between 2015 and 2022 using the keywords (with wildcards) "allerg*," "immunotherap*," "mechanis*," and "asthma." Among the cited references, additional references were identified using a manual search.

Role of human milk oligosaccharide metabolizing bacteria in the development of atopic dermatitis/eczema

Despite affecting up to 20% of infants in the United States, there is no cure for atopic dermatitis (AD), also known as eczema. Atopy usually manifests during the first six months of an infant's life and is one predictor of later allergic health problems. A diet of human milk may offer protection against developing atopic dermatitis. One milk component, human milk oligosaccharides (HMOs), plays an important role as a prebiotic in establishing the infant gut microbiome and has immunomodulatory effects on the infant immune system. The purpose of this review is to summarize the available information about bacterial members of the intestinal microbiota capable of metabolizing HMOs, the bacterial genes or metabolic products present in the intestinal tract during early life, and the relationship of these genes and metabolic products to the development of AD/eczema in infants. We find that specific HMO metabolism gene sets and the metabolites produced by HMO metabolizing bacteria may enable the protective role of human milk against the development of atopy because of interactions with the immune system. We also identify areas for additional research to further elucidate the relationship between the human milk metabolizing bacteria and atopy. Detailed metagenomic studies of the infant gut microbiota and its associated metabolomes are essential for characterizing the potential impact of human milk-feeding on the development of atopic dermatitis.

Biological impact of sequential exposures to allergens and ultrafine particle-rich combustion aerosol on human bronchial epithelial BEAS-2B cells at the air liquid interface

The prevalence of allergic diseases is constantly increasing since few decades. Anthropogenic ultrafine particles (UFPs) and allergenic aerosols is highly involved in this increase; however, the underlying cellular mechanisms are not yet understood. Studies observing these effects focused mainly on singular in vivo or in vitro exposures of single particle sources, while there is only limited evidence on their subsequent or combined effects. Our study aimed at evaluating the effect of subsequent exposures to allergy-related anthropogenic and biogenic aerosols on cellular mechanism exposed at air-liquid interface (ALI) conditions. Bronchial epithelial BEAS-2B cells were exposed to UFP-rich combustion aerosols for 2 h with or without allergen pre-exposure to birch pollen extract (BPE) or house dust mite extract (HDME). The physicochemical properties of the generated particles were characterized by state-of-the-art analytical instrumentation. We evaluated the cellular response in terms of cytotoxicity, oxidative stress, genotoxicity, and in-depth gene expression profiling. We observed that single exposures with UFP, BPE, and HDME cause genotoxicity. Exposure to UFP induced pro-inflammatory canonical pathways, shifting to a more xenobiotic-related response with longer preincubation time. With additional allergen exposure, the modulation of pro-inflammatory and xenobiotic signaling was more pronounced and appeared faster. Moreover, aryl hydrocarbon receptor (AhR) signaling activation showed to be an important feature of UFP toxicity, which was especially pronounced upon pre-exposure. In summary, we were able to demonstrate the importance of subsequent exposure studies to understand realistic exposure situations and to identify possible adjuvant allergic effects and the underlying molecular mechanisms.

Filaggrin Gene Mutation in Pediatric Patients with Atopic Dermatitis: A Look into Indian Gene Pool, a Pilot Study

Background

Mutations in the filaggrin (FLG) gene has been reported to be an indicator of poor prognosis of atopic dermatitis (AD). It has been reported that there is a considerable variation in the mutations detected in the FLG gene in different ethnicities.

Aim

To detect the presence of mutations in the FLG gene in pediatric subjects with atopic dermatitis (AD) and to compare the detected mutations with those already reported from different ethnicities.

Materials and Methods

Genomic DNA extracted using standard procedure from peripheral venous blood of 30 patient and 15 control samples. Sequence analysis of the FLG gene carried out and detected changes was then cross referenced with those mutations already reported to check for novelty of detected changes.

Results

Amino acid changes were detected in 28 of the patient samples and in none of the control samples indicating that changes in the FLG gene were more common in the patient group than the control group (Fishers exact test, P < 0.0001). The most commonly reported mutations R501X and 2282del4 were not detected. Only 5 of the detected 22 amino acid changes H2507Q, L2481S, K2444E, E2398Q, and S2366T have been previously reported and are not clinically significant; however, in one patient a stop codon was detected (S2366STOP). P2238N, R2239W, and V2243L detected in 70% of the samples and S2231E detected in 67% of the patient samples have not been reported so far and their clinical significance is yet to be analyzed.

Conclusion

Analyses of mutations already reported showed that the changes detected from this study are novel to Indian traits. While this adds on to the minimal data available from the Indian subcontinent further analyses has to be carried out to analyze the pathogenicity of these detected changes on larger samples sizes.

Aim

To detect the presence of mutations in the FLG gene in pediatric subjects with atopic dermatitis (AD) and to compare the detected mutations with those already reported from different ethnicities.

Sensitization pattern to environmental allergens in a Japanese population

Background

We previously described the prevalence of allergen-specific IgE in a general population of Japanese adults.

Objective

We sought to elucidate allergen sensitization patterns in this population.

Methods

Serum samples had been obtained from 800 blood donors aged 20 to 59 years and living in Tokyo, Japan, in 2005 and stored in the Japanese Red Cross Society. These samples were examined for IgE levels, total and specific for 23 allergens or allergen sources correlated with allergic airway diseases using the ImmunoCAP method. Exploratory and confirmatory factor analyses were performed to uncover the relationship among allergen-specific IgE based on their titers. Hierarchical cluster analysis was executed using Ward's method based on standardized factor scores identified through factor analysis.

Results

Exploratory factor analysis revealed 6 categories of allergen-specific IgE: specific to 2 types of animals (insects and Dermatophagoides pteronyssinus/animal dander), 2 types of pollens (group 1 [Japanese cedar and cypress] and group 2 [alder, grass, and weeds]), and 2 types of microorganisms (fungi and commensal microorganisms on the skin). The Japanese population was categorized into 3 clusters: (A) nonatopic type, (B) house dust mite-dominant sensitization type, and (C) panatopic type. The panatopic group could be further classified into 2 subclusters positive and negative for fungal sensitization.

Conclusions

This study demonstrated that a Japanese population could be divided into 3 clusters according to the sensitization pattern to 6 types of allergens.

Influence of Farm Environment on Asthma during the Life Course: A Population-Based Birth Cohort Study in Northern Finland

We investigated the influence of a farming environment on asthma at three time points from birth to 46 years using the Northern Finland Birth Cohort 1966 (n = 10,926). The prevalence of asthma was investigated by postal questionnaires at 14, 31 and 46 years of age. Exposure to a farming environment was assessed by a postal questionnaire at birth and at 31 and 46 years of age. Odds ratios (ORs) and their 95% confidence intervals (95% CIs) for the prevalence of asthma were obtained from multinomial logistic regression, stratified by sex. Being born in a farmer family was potentially causally associated with lower risk of asthma in males at 31 years of age (OR 0.56, 95% CI 0.37, 0.85) and in females at 46 years of age (OR 0.64, 95% CI 0.44, 0.95). Working as a farmer was not associated with asthma. Exposure to a farming environment in childhood may have a lifelong impact on developing asthma from birth through young adulthood and until middle age, indicating that 'immune deviation' may persist throughout life.

Relationship Between Atopic Dermatitis and Food Allergy in Children

Atopic dermatitis (AD) is a chronic inflammatory skin condition characterized by a compromised skin barrier due to a variety of reasons, such as hereditary predisposition, immunological overactivity, and skin microbiome disruption. There is strong evidence linking food allergies (FA) with AD in some children, and many children with AD develop asymptomatic food sensitivity. FA and AD are two frequent childhood illnesses that are closely related. Food allergies affect 30% of kids suffering from moderate and severe eczema and can cause a variety of symptoms, including dry, cracked skin, rash, itchiness, oozing, and crusted skin. While preteens and teens with AD are commonly sensitive to environmental allergens including house dust mites, mold, pollen, or dander of animals, younger kids with AD typically exhibit sensitivity to food items like peanuts, milk, or eggs. A food challenge test (FC) should be used to confirm allergies before recommending a stringent diet that could be hazardous to the patient. While elimination diets continue to be the cornerstone of the management of FA, they should only be carried out under the guidance of a specialist. Topical treatments are crucial for all individuals with AD. Early skin care with emollients, topical steroid treatment, and early introduction of highly allergenic foods are promising methods of alleviating symptoms of AD.

The top 100 most cited articles in the last two decades of atopic dermatitis: A bibliometric analysis

Background

Atopic dermatitis (AD) is the leading cause of skin-related disease burden worldwide, affecting a large percentage of the population. Bibliometrics is the statistical analysis of academic literature in a certain field.

Objectives

We aimed to perform the latest bibliometric analysis of atopic dermatitis literature.

Methods

We searched the Web of Science database on 29th Nov 2021. We used the keywords "atopic dermatitis," "atopic eczema," and "eczema" for our search. All items published between 2001 and 2021 were included. The top 100 most cited articles were identified and analyzed.

Results

Our study provided a detailed bibliometric analysis of the top 100 most cited articles on atopic dermatitis. These articles were published between 2002 and 2019 and were from 15 different countries, mostly in the USA and Germany. Most articles have focused on the pathogenesis and treatment of AD. The Journal of Allergy and Clinical Immunology made the greatest contribution to the top 100 list, with 28 articles. The most cited article originated from Lancet. The highest number of citations was seen in 2006, with 9220 citations, while the highest number of publications was seen in 2006 with 12 publications.

Conclusions

Our study aims to provide physicians and researchers with a historical perspective for the scientific progress of atopic dermatitis, and help clinicians effectively obtain useful articles that have a significant impact on the field of atopic dermatitis.

Sialic acid and food allergies: The link between nutrition and immunology

Food allergies (FA), a major public health problem recognized by the World Health Organization, affect an estimated 3%-10% of adults and 8% of children worldwide. However, effective treatments for FA are still lacking. Recent advances in glycoimmunology have demonstrated the great potential of sialic acids (SAs) in the treatment of FA. SAs are a group of nine-carbon α-ketoacids usually linked to glycoproteins and glycolipids as terminal glycans. They play an essential role in modulating immune responses and may be an effective target for FA intervention. As exogenous food components, sialylated polysaccharides have anti-FA effects. In contrast, as endogenous components, SAs on immunoglobulin E and immune cell surfaces contribute to the pathogenesis of FA. Given the lack of comprehensive information on the effects of SAs on FA, we reviewed the roles of endogenous and exogenous SAs in the pathogenesis and treatment of FA. In addition, we considered the structure-function relationship of SAs to provide a theoretical basis for the development of SA-based FA treatments.

Phenotype of Atopic Dermatitis With Food Allergy Predicts Development of Childhood Asthma via Gut Wnt Signaling

PURPOSE

Atopic dermatitis (AD) is a chronic inflammatory skin disease characterized by a wide spectrum of clinical phenotype. However, specific description of phenotypes of AD depending on the comorbidities in early childhood is lacking. This study aimed to investigate whether the AD phenotype in early childhood is related to childhood asthma and to elucidate the mechanisms involved.

METHODS

Data on the first 3 years of life were collected prospectively from 1,699 children in the COhort for Childhood Origin of Asthma and allergic diseases (COCOA). We applied an unsupervised latent class analysis to the following five factors: food sensitization, inhalant sensitization, food allergy (FA), AD, and recurrent wheezing. The risks of developing FA, AD, allergic rhinitis (AR), and asthma in children aged 5-7 years were evaluated. Colonocyte transcriptome and ingenuity pathway analysis were performed.

RESULTS

Four phenotypes were identified; no allergic diseases (78.4%), AD without sensitization (16.4%), FA with AD (2.9%), and AD with sensitization (7.8%). The FA with AD had the highest risk for FA, AR, and asthma and the highest cord blood immunoglobulin E (IgE) levels. In AD without sensitization and with sensitization, scoring of AD (SCORAD) in early childhood was higher than in FA with AD. Canonical pathway analysis with the colonocyte transcriptome revealed that the key pathway in FA with AD was 'Wnt/β-catenin Signaling.' The relative abundance of Wnt6 mRNA was positively correlated with food-specific IgE levels at 1 and 3 years.

CONCLUSIONS

When FA is present in various phenotypes of AD at early life, regardless of severity of eczema, it may be associated with gut Wnt signaling and later development of asthma.

Evolution of Eczema, Wheeze, and Rhinitis from Infancy to Early Adulthood: Four Birth Cohort Studies

Rationale: The relationship between eczema, wheeze or asthma, and rhinitis is complex, and epidemiology and mechanisms of their comorbidities is unclear. Objectives: To investigate within-individual patterns of morbidity of eczema, wheeze, and rhinitis from birth to adolescence/early adulthood. Methods: We investigated onset, progression, and resolution of eczema, wheeze, and rhinitis using descriptive statistics, sequence mining, and latent Markov modeling in four population-based birth cohorts. We used logistic regression to ascertain if early-life eczema or wheeze, or genetic factors (filaggrin [FLG] mutations and 17q21 variants), increase the risk of multimorbidity. Measurements and Main Results: Single conditions, although the most prevalent, were observed significantly less frequently than by chance. There was considerable variation in the timing of onset/remission/persistence/intermittence. Multimorbidity of eczema+wheeze+rhinitis was rare but significantly overrepresented (three to six times more often than by chance). Although infantile eczema was associated with subsequent multimorbidity, most children with eczema (75.4%) did not progress to any multimorbidity pattern. FLG mutations and rs7216389 were not associated with persistence of eczema/wheeze as single conditions, but both increased the risk of multimorbidity (FLG by 2- to 3-fold, rs7216389 risk variant by 1.4- to 1.7-fold). Latent Markov modeling revealed five latent states (no disease/low risk, mainly eczema, mainly wheeze, mainly rhinitis, multimorbidity). The most likely transition to multimorbidity was from eczema state (0.21). However, although this was one of the highest transition probabilities, only one-fifth of those with eczema transitioned to multimorbidity. Conclusions: Atopic diseases fit a multimorbidity framework, with no evidence for sequential atopic march progression. The highest transition to multimorbidity was from eczema, but most children with eczema (more than three-quarters) had no comorbidities.

Association of Exclusive Breastfeeding with Asthma Risk among Preschool Children: An Analysis of National Health and Nutrition Examination Survey Data, 1999 to 2014

Breastmilk contains many important nutrients, anti-inflammatory agents, and immunomodulators. It is the preferred nutrition source for infants. However, the association of the duration of exclusive breastmilk feeding (BMF) with asthma development is unclear. Data on children from the United States who participated in the National Health and Nutrition Examination Survey (NHANES) from 1999 to 2014 were obtained. We examined the association between the duration of exclusive BMF and asthma in 6000 children (3 to 6 years old). After calculating the duration of exclusive breastfeeding according to answers to NHANES questionnaires, the estimated duration of exclusive BMF was divided into five categories: never breastfed or BMF for 0 to 2 months after birth; BMF for 2 to 4 months after birth; BMF for 4 to 6 months after birth; and BMF for ≥6 months after birth. The overall prevalence of asthma in children aged 3 to 6 years was approximately 13.9%. The risk of asthma was lower in children with an exclusive BMF duration of 4 to 6 months (aOR, 0.69; 95% CI, 0.48–0.98), after adjustment for potentially confounding factors. Subgroup analysis revealed that children of younger ages (3 to 4 years old) benefited most from the protective effects of exclusive BMF for 4 to 6 months (aOR, 0.47; 95% CI, 0.27, 0.8). We found that exclusive BMF, especially BMF for 4 to 6 months, is associated with a decreased risk of asthma in preschool-age children. The protective effect appeared to be diminished in older children. The potential mechanism needs further investigation.

Mechanisms and biomarkers of successful allergen-specific immunotherapy

Allergen-specific immunotherapy (AIT) is considered the only curative treatment for allergic diseases mediated by immunoglobulin E (IgE). Currently, the route of administration depends both on the different types of causal allergens and on its effectiveness and safety profile. Several studies have reported the mechanisms and changes in humoral and cellular response underlying AIT; however, the full picture remains unknown. Knowledge of who can benefit from this type of treatment is urgently needed due to the patient safety risks and costs of AIT. In vivo or in vitro biomarkers have become a strategy to predict clinical outcomes in precision medicine. There are currently no standardized biomarkers that allow determining successful responses to AIT, however, some studies have found differences between responders and nonresponders. In addition, different candidates have been postulated that may have the potential to become biomarkers. In this review, we aim to summarize the findings to date related to biomarkers in different IgE-mediated allergic diseases (respiratory, food, and venom allergy) with the potential to define who will benefit from AIT.

Pentadecanoylcarnitine is a newly discovered endocannabinoid with pleiotropic activities relevant to supporting physical and mental health

As an emerging dietary essential fatty acid, pentadecanoic acid (C15:0) is expected to have bioactive metabolites with broad health benefits. Here, we evaluated pentadecanoylcarnitine, an endogenous C15:0 metabolite, for dose dependent cell-based activities, including measurement of its effects on 148 clinically relevant biomarkers across twelve primary human cell systems mimicking various disease states. Mechanisms of action for pentadecanoylcarnitine were also assessed across 78 cell-based target assays. Pentadecanoylcarnitine had dose-dependent anti-inflammatory activities, including lower IL-1α, ITAC, MCP-1, and IP-10, across five cell systems relevant to treating cardiovascular, immune, neoplastic, pulmonary, and skin diseases. Targeted assays showed pentadecanoylcarnitine as a full-acting cannabinoid 1 and 2 receptor agonist (EC50 3.7 and 3.2 µM, 111% and 106% maximum activity compared to the positive control, respectively). Pentadecanoylcarnitine also had 5-HT1A and 5-HT1B receptor agonist and histamine H1 and H2 receptor antagonist activities. In summary, pentadecanoylcarnitine, a second discovered full-acting endocannabinoid, had broad pleiotropic activities relevant to regulating inflammation, pain, mood, and sleep. This study's findings further the need to evaluate the potential health impacts of C15:0 nutritional deficiencies caused by population-wide avoidance of all dietary saturated fats, including C15:0.