The causal relationship between atopic dermatitis and brain cancer: A bidirectional Mendelian randomization study.

BACKGROUND: Atopic dermatitis ranks among the prevalent skin disorders. Research has indicated a potential association with brain cancer. Yet, establishing a direct causal relationship between atopic dermatitis and brain cancer continues to be challenging. MATERIALS AND METHODS: We extracted single nucleotide polymorphisms (SNPs) significantly associated with atopic dermatitis (sample size = 382 254) at a genome-wide level from a large Finnish Genome-Wide Association Study (GWAS) dataset (n cases = 15 208, n controls = 367 046). Summary data for 372 622 cases of brain cancer (n cases = 606, n controls = 372 016) were obtained via the IEU Open GWAS database. We employed the Inverse Variance Weighted (IVW) method as our primary analytical approach for Mendelian Randomization (MR) analysis. Additionally, heterogeneity was measured using Cochran's Q value, and horizontal pleiotropy was evaluated using MR-Egger 、Mendelian Randomization Pleiotropy RESidual Sum and Outlier and leave-one-out analyses. RESULTS: The risk of brain cancer increases with the presence of atopic dermatitis, as evidenced by the odds ratios (ORs) and 95% confidence intervals (CIs),(OR = 1.0005; 95% CI = 1.0001, 1.0009; p = 0.0096). However, when conducting the analysis in reverse, no significant link was observed. CONCLUSION: The findings from our study indicate a causative link between atopic dermatitis and brain cancer, highlighting the importance of conducting broader clinical investigations into their potential association going forward.

Filaggrin Mutation Status and Prevention of Atopic Dermatitis with Maternal Probiotic Supplementation.

The World Allergy Organization recommends probiotics in the prevention of atopic dermatitis in high-risk populations. Mutations in the filaggrin gene (FLG) result in an increased risk of atopic dermatitis through disruption of the skin keratin layer. This exploratory study investigated whether the preventive effect of maternal probiotics was evident in children with and without FLG mutations. DNA was collected from children (n = 228) from the Probiotic in the Prevention of Allergy among Children in Trondheim (ProPACT) study. Samples were analysed for 3 common FLG mutations (R501X, R2447X, and 2282del4). Overall, 7% of children had heterozygous FLG mutations; each child had only one of the 3 mutations. Mutation status had no association with atopic dermatitis (RR = 1.1; 95% CI 0.5 to 2.3). The risk ratio (RR) for having atopic dermatitis following maternal probiotics was 0.6 (95% CI 0.4 to 0.9) and RR was similar if the child expressed an FLG mutation (RR = 0.6; 95% CI 0.1 to 4.1) or wildtype FLG (RR = 0.6; 95% CI 0.4 to 0.9). The preventive  effect of probiotics for atopic dermatitis was also evident in children without FLG mutation. Larger confirmatory studies are needed.

KRT6A Inhibits IL-1ß-Mediated Pyroptosis of Keratinocytes via Blocking IL-17 Signaling.

Keratin 6A (KRT6A) is involved in the pathogenesis of various skin diseases. However, the reports on the roles of KRT6A in atopic dermatitis (AD) are limited. This study aimed to investigate the potentials of KRT6A in AD. mRNA levels were detected by RT-PCR. Cytokine release was determined by ELISA. Protein expression was determined using Western blot. Cell viability was determined by CCK-8. Cytotoxicity was detected by LDH assay. Cell death was determined by TUNEL. The pyroptosis of keratinocytes was detected using flow cytometry. We found that KRT6A was overexpressed in AD patients. Moreover, KRT6A was stimulated after exposed to proinflammatory cytokines. Overexpressed KRT6A suppressed inflammatory response, while KRT6A knockdown exerted the opposite effects. Overexpressed KRT6A suppressed inflammation-induced pyroptosis of keratinocytes. Additionally, KRT6A negatively regulated interleukin-17a (IL-17a) expression, blocking IL-17 signaling. IL-17a overexpression antagonized the effects of KRT6A and promoted pyroptosis of keratinocytes. In conclusion, KRT6A exerted protective functions in AD via regulating IL-17 signaling. This KRT6A/IL-17 may be a novel target for AD.

Association between polymorphisms and atopic dermatitis susceptibility: A systematic review and meta-analysis.

AIM: Atopic dermatitis (AD) is a chronic pruritic inflammatory skin disease that is closely linked to genetic factors. Previous studies have revealed numerous single nucleotide polymorphisms (SNPs) that been related to susceptibility to AD; however, the results are conflicting. Therefore, a meta-analysis was conducted to assess the associations of these polymorphisms and AD risk. MATERIAL AND METHODS: PubMed, Web of Science, Embase, Cochrane Library, and China National Knowledge Infrastructure databases were retrieved to identify eligible studies, with selected polymorphisms being reported in a minimum of three separate studies. The Newcastle-Ottawa Scale (NOS) was used to evaluate study quality. Review Manager 5.3 and STATA 14.0 were used to perform the meta-analysis. RESULTS: After screening, 64 studies involving 13 genes (24 SNPs) were selected for inclusion in the meta-analysis. Nine SNPs were positively correlated with AD susceptibility [filaggrin (FLG) R501X, FLG 2282del4, chromosome 11q13.5 rs7927894, interleukin (IL)-17A rs2275913, IL-18 -137 G/C, Toll-like receptor 2 (TLR2) rs5743708, TLR2 A-16934 T, serine protease inhibitor Kazal type-5 (SPINK5) Asn368Ser, interferon-γ (IFN-γ) T874A] and one was negatively associated with AD susceptibility (IL-4 -1098 T/G). The 14 remaining SNPs were not significantly associated with AD susceptibility. CONCLUSIONS: Nine SNPs that may be risk factors and one SNP that may be a protective factor for AD were identified, providing a reference for AD prediction, prevention, and therapy.

The causal relationship between gut microbiota and immune skin diseases: A bidirectional Mendelian randomization.

BACKGROUND: Increasing evidence suggests that alterations in gut microbiota are associated with a variety of skin diseases. However, whether this association reflects a causal relationship remains unknown. We aimed to reveal the causal relationship between gut microbiota and skin diseases, including psoriasis, atopic dermatitis, acne, and lichen planus. METHODS: We obtained full genetic association summary data for gut microbiota, psoriasis, atopic dermatitis, acne, and lichen planus from public databases and used three methods, mainly inverse variance weighting, to analyze the causal relationships between gut microbiota and these skin diseases using bidirectional Mendelian randomization, as well as sensitivity and stability analysis of the results using multiple methods. RESULTS: The results showed that there were five associated genera in the psoriasis group, seven associated genera were obtained in the atopic dermatitis group, a total of ten associated genera in the acne group, and four associated genera in the lichen planus group. The results corrected for false discovery rate showed that Eubacteriumfissicatenagroup (P = 2.20E-04, OR = 1.24, 95%CI:1.11-1.40) and psoriasis still showed a causal relationship. In contrast, in the reverse Mendelian randomization results, there was no evidence of an association between these skin diseases and gut microbiota. CONCLUSION: We demonstrated a causal relationship between gut microbiota and immune skin diseases and provide a new therapeutic perspective for the study of immune diseases: targeted modulation of dysregulation of specific bacterial taxa to prevent and treat psoriasis, atopic dermatitis, acne, and lichen planus.

Spatial transcriptomics reveals altered lipid metabolism and inflammation-related gene expression of sebaceous glands in psoriasis and atopic dermatitis.

Sebaceous glands drive acne, however, their role in other inflammatory skin diseases remains unclear. To shed light on their potential contribution to disease development, we investigated the spatial transcriptome of sebaceous glands in psoriasis and atopic dermatitis patients across lesional and non-lesional human skin samples. Both atopic dermatitis and psoriasis sebaceous glands expressed genes encoding key proteins for lipid metabolism and transport such as ALOX15B, APOC1, FABP7, FADS1/2, FASN, PPARG, and RARRES1. Also, inflammation-related SAA1 was identified as a common spatially variable gene. In atopic dermatitis, genes mainly related to lipid metabolism (e.g. ACAD8, FADS6, or EBP) as well as disease-specific genes, i.e., Th2 inflammation-related lipid-regulating HSD3B1 were differentially expressed. On the contrary, in psoriasis, more inflammation-related spatially variable genes (e.g. SERPINF1, FKBP5, IFIT1/3, DDX58) were identified. Other psoriasis-specific enriched pathways included lipid metabolism (e.g. ACOT4, S1PR3), keratinization (e.g. LCE5A, KRT5/7/16), neutrophil degranulation, and antimicrobial peptides (e.g. LTF, DEFB4A, S100A7-9). In conclusion, our results show that sebaceous glands contribute to skin homeostasis with a cell type-specific lipid metabolism, which is influenced by the inflammatory microenvironment. These findings further support that sebaceous glands are not bystanders in inflammatory skin diseases, but can actively and differentially modulate inflammation in a disease-specific manner.

Causal association between atopic dermatitis and Parkinson's disease: A bidirectional Mendelian randomization study.

BACKGROUND: Atopic dermatitis is one of the most common skin disorders. Evidence has suggested an association between skin disorders, such as atopic dermatitis, and Parkinson's disease (PD). However, whether atopic dermatitis has a causal effect on PD remains unknown. METHODS: The study aimed to determine whether their association between atopic dermatitis and PD is causal, using a bidirectional two-sample Mendelian randomization method. Genetic variants from the public genome-wide association studies for atopic dermatitis (n = 10788 cases and 30047 controls) were selected to evaluate their causal effects on the risk of PD (33,674 cases and 449,056 controls). The inverse variance weighted (IVW) method was used as the primary analysis. RESULTS: The IVW results indicated that atopic dermatitis was associated with decreased risk of PD {fixed effects: odds ratio [OR] [95% confidence interval (CI)]: .905 [.832-.986], p = .022; OR [95% CI]: .905 [.827-.991], p = .032}. However, we failed to detect the causal effects of PD on risk of atopic dermatitis in the reverse causation analysis. CONCLUSION: This study indicated causal association of genetically proxied atopic dermatitis with the risk of PD. Future studies are warranted to explore the underlying mechanism and investigate the targeting effect of atopic dermatitis on PD.

Association between CCL5, CCL11, and CCL17 polymorphisms and atopic dermatitis risk: A systematic review and meta-analysis.

BACKGROUND: Atopic dermatitis (AD) is a common and recurrent inflammatory disease with strong genetic susceptibility. The abnormal production of chemokines plays an important role in the occurrence and development of AD. METHODS: A comprehensive online literature search was performed in databases of China National Knowledge Infrastructure, Wanfang, VIP China Science and Technology Journal Database, China Biomedical Literature Database, PubMed, Embase and Cochrane Library to retrieve relevant articles published from January 2000 to October 2022. The odds ratio (OR) with its 95% confidence interval (CI) was employed to calculate this relationship. RESULTS: A total of 7 studies were finally screened out, including 1316 AD patients and 1099 controls. There were 3 studies for CC chemokine ligand 5 (CCL5) polymorphisms, 2 for CCL11 polymorphisms, and 2 for CCL17 polymorphisms, respectively. The meta-analysis revealed a significant association between the CCL5 - 403G/A polymorphism and AD under the allelic model (A vs G: OR = 1.25, 95% CI = 1.02-1.52, P = .03), heterozygous model (AG vs GG: OR = 1.40, 95% CI = 1.08-1.80, P = .01) and dominant model (AA + AG vs GG: OR = 1.38, 95% CI = 1.08-1.76, P = .01) in a fixed-effect model. The allelic model (G vs C: OR = 1.46, 95% CI = 1.07-1.98, P < .01) and dominant model (GG + GC vs CC: OR = 1.74, 95% CI = 1.23-2.47, P < .001) of the CCL5 - 28C/G polymorphism were also associated with an increased risk of AD. However, this significant association was not found in other alleles and genotypes (P > .05). CONCLUSION: Our results show that the A allele, AG and AA + AG genotypes of the CCL5 - 403G/A polymorphism, the G allele and GG + GC genotype of the CCL5 - 28C/G polymorphism are risk factors for AD. Future studies with large population are still needed to further explore those correlations.

LIGHT signaling through LTßR and HVEM in keratinocytes promotes psoriasis and atopic dermatitis-like skin inflammation.

Psoriasis (PS) and atopic dermatitis (AD) are common skin inflammatory diseases characterized by hyper-responsive keratinocytes. Although, some cytokines have been suggested to be specific for each disease, other cytokines might be central to both diseases. Here, we show that Tumor necrosis factor superfamily member 14 (TNFSF14), known as LIGHT, is required for experimental PS, similar to its requirement in experimental AD. Mice devoid of LIGHT, or deletion of either of its receptors, lymphotoxin ß receptor (LTßR) and herpesvirus entry mediator (HVEM), in keratinocytes, were protected from developing imiquimod-induced psoriatic features, including epidermal thickening and hyperplasia, and expression of PS-related genes. Correspondingly, in single cell RNA-seq analysis of PS patient biopsies, LTßR transcripts were found strongly expressed with HVEM in keratinocytes, and LIGHT was upregulated in T cells. Similar transcript expression profiles were also seen in AD biopsies, and LTßR deletion in keratinocytes also protected mice from allergen-induced AD features. Moreover, in vitro, LIGHT upregulated a broad spectrum of genes in human keratinocytes that are clinical features of both PS and AD skin lesions. Our data suggest that agents blocking LIGHT activity might be useful for therapeutic intervention in PS as well as in AD.

Systemic lupus erythematosus and Atopic dermatitis: A two sample Mendelian randomization study.

BACKGROUND: Systemic lupus erythematosus (SLE) and atopic dermatitis (AD) are common diseases in human populations. Previous studies have suggested a potential association between SLE and AD. However, the causal relationship and direction between the two conditions remain unclear. OBJECTIVE: The aim of this study is to evaluate the causal relationship between SLE and AD. METHODS: In this study, we employed Mendelian randomization (MR) analysis to investigate the causal relationship between SLE and AD. MR analysis has the advantage of reducing confounding factors, determining the direction of causality, and providing quantitative effect estimates. We obtained summary data from genome-wide association studies (GWAS) on SLE and AD from publicly available databases. Five MR methods, namely MR Egger, weighted median, inverse variance weighted, simple mode, and weighted mode, were used to assess the causal relationship between SLE and AD. Several techniques, including MR-Egger intercept, MR-PRESSO, and Cochran's Q test, were utilized to evaluate heterogeneity and pleiotropy. RESULTS: Our study demonstrated a causal relationship between the prevalence of SLE and an increased risk of AD (MR Egger OR: 1.567, 95% CI: [1.041, 1.285], P = 0.009; IVW OR: 1.085, 95% CI: [1.005, 1.143], P = 0.035). Furthermore, sensitivity analyses did not detect heterogeneity or pleiotropy. CONCLUSION: Our research finds that SLE is a contributing factor to the development of AD, providing valuable insights into the pathogenesis and prevention of both diseases. Key Points • Currently, there is no research that clearly indicates a causal relationship between SLE and AD. This study, for the first time, identified a positive causal relationship between SLE and AD. • The results of this study contribute to our understanding of the pathogenesis and treatment strategies for SLE and AD, providing some guidance for future clinical practice.

Association between filaggrin gene mutations and the clinical features of molluscum contagiosum: The Yamanashi Adjunct Study of the Japan Environment and Children's Study.

Previous studies have reported swimming, atopic dermatitis, and filaggrin (FLG) gene mutations as risk factors for molluscum contagiosum (MC) infection. FLG gene mutations impair skin barrier function. The aim of this study was to determine the impact of FLG mutations on the incidence and clinical features of MC. We used data from 2036 children who participated in the Yamanashi Adjunct Study of the Japan Environment and Children's Study, a prospective, birth cohort study. A questionnaire for caregivers (when children were 4 and 8 years of age) asked about clinical features including previous MC incidence and treatment, number of MC lesions at first visit, and time to resolution. Participants underwent genotyping to detect six FLG mutations that are common in the Japanese population. A logistic regression model was used to analyze the association between MC incidence and FLG mutations, adjusted for potential confounders. The cumulative incidence of MC at age 8 years was 47.1%. Among participants with a history of MC, 67.6% had undergone curettage. FLG mutation was a significant risk factor for MC incidence (adjusted odds ratio [aOR] 1.69, 95% confidence interval [CI] 1.18-2.42). Swimming and atopic dermatitis were also significant risk factors for MC. There was no significant association between FLG mutation and the number of MC lesions at the first visit or the time to resolution of lesions. FLG mutation is a risk factor for MC incidence; however, FLG mutations do not affect the number of MC lesions at presentation or the time to resolution.

The associations between gut microbiota and inflammatory skin diseases: a bi-directional two-sample Mendelian randomization study.

Background: Accumulating evidence shows that dysregulation of intestinal flora is associated with inflammatory skin diseases, specifically atopic dermatitis (AD), psoriasis (PSO), and rosacea (ROS). However, the causality is still unclear. Objectives: To study the underlying causality between gut microbiota (GM) and AD, PSO, and ROS, a bi-directional two-sample Mendelian randomization (2SMR) analysis was conducted. Methods: Summary statistics of gut microbiota, AD, PSO, and ROS were extracted from large-scale genome-wide association studies (GWASs). In 2SMR analysis, in addition to the inverse variance weighted as the principal method for evaluating causal association, four different methods were also used. Sensitivity analysis and reverse 2SMR study were implemented to evaluate the robustness of 2SMR results or reverse causal relationship, respectively. Results: A total of 24 specific gut microbiota species related to AD, PSO, and ROS were identified by 2SMR analysis. After using the Bonferroni method for multiple testing correction, family FamilyXIII (ID: 1957) [OR = 1.28 (1.13, 1.45), p = 9.26e-05] and genus Eubacteriumfissicatenagroup (ID: 14373) [OR = 1.20 (1.09, 1.33), p = 1.65e-04] were associated with an increased risk for AD and PSO, respectively. The genus Dialister showed a negative association, suggesting a protective role against both atopic dermatitis and rosacea. Our reverse 2SMR analysis indicated no reverse causality between these inflammatory skin diseases and the identified gut microbiota. Conclusions: In summary, this study provided evidence for the causality between GM and inflammatory skin diseases. These findings suggested that supplementing specific bacterial taxa may be an effective therapy for AD, PSO, and ROS.

The Association of Vitamin D Receptor Gene Polymorphisms with Vitamin D, Total IgE, and Blood Eosinophils in Patients with Atopy.

BACKGROUND: In order to improve the control of atopic diseases, it is important to clarify the pathogenesis of atopy and identify its various triggers. Single nucleotide polymorphisms (SNPs) of the vitamin D receptor gene (VDR) may impact atopy. The aim of this study was to investigate the possible associations between VDR SNPs and vitamin D, total IgE, and eosinophils in atopy. METHODS: In total, 203 adults, including 122 patients with atopic diseases (45 with atopic dermatitis, 77 with allergic asthma) and 81 healthy controls, were involved in the study. The blood eosinophil count was determined with an automated hematology analyzer. Vitamin D and total immunoglobulin E (IgE) levels were evaluated using the ELISA method. Polymorphisms in the VDR gene were analyzed with real-time PCR using TaqMan probes. RESULTS: We analyzed six VDR single nucleotide polymorphisms and found a significant association between VDR rs731236 GG genotype and normal vitamin D levels in atopic patients and healthy subjects (OR 11.33; 95% CI: 1.049-122.388 and OR 4.04; 95% CI: 1.117-14.588, respectively, p < 0.05). Additionally, the study results revealed a significant relationship between the VDR rs2228570 GG genotype and normal vitamin D levels in patients with atopy and healthy subjects (OR 3.80; 95% CI: 1.190-12.134 and OR 2.09; 95% CI: 1.044-4.194, respectively, p < 0.05). The rs2228570 allele A was associated with decreased vitamin D levels in patients with atopy and healthy subjects (OR 0.28; 95% CI: 0.098-0.804 and OR 0.229; 95% CI: 0.069-0.761, respectively, p < 0.05). The VDR rs3847987 genotypes AA and AC were significantly associated with normal vitamin D levels in healthy subjects (OR 35.99; 95% CI: 6.401-202.446 and OR 4.72; 95% CI: 1.489-15.007, respectively, p < 0.05). In addition, a decreased amount of vitamin D was associated with atopic diseases such as atopic dermatitis and allergic asthma (OR 0.49; 95% CI: 0.439-1.308 and OR 0.58; 95% CI: 0.372-0.908, respectively, p < 0.05). The rs11168293 allele T was associated with the normal range of total IgE in atopy (OR 2.366; 95% CI: 1.133-5.027; p < 0.05). Significant associations were found between VDR rs731263 allele G, rs11168293 allele G, and increased blood eosinophil levels in patients with atopy (OR 0.319; 95% CI: 0.163-0.934 and OR 0.323; 95% CI: 0.112-0.935, respectively, p < 0.05). CONCLUSIONS: A decreased vitamin D level showed a significant relationship with atopic diseases (atopic dermatitis and allergic asthma). The association between the VDR gene polymorphisms rs2228570, rs731236, and rs11168293 and vitamin D, total IgE, and blood eosinophils in patients with atopy suggested that VDR polymorphisms and the vitamin D level should be considered when examining the factors associated with atopy.

Molecular characterization of allergic constitution based on network pharmacology and multi-omics analysis methods.

The objective of this study was to identify critical pathways associated with allergic constitution. Shared genes among allergic rhinitis (AR), asthma (AA), and atopic dermatitis (AD) were extracted from the GWAS catalog. RNA-seq data of AR, AA, and AD from gene expression omnibus (GEO) database were preprocessed and subjected to differential gene expression analysis. The differentially expressed genes (DEGs) were merged using the Robust Rank Aggregation (RRA) algorithm. Weighted gene co-expression network analysis (WGCNA) was performed to identify modules associated with allergies. Components of Guominkang (GMK) were obtained from 6 databases and activate components were identified by SwissADME website. Utilizing the SwissTarget Prediction, PharmMapper, SymMap, and HERB, the targets of GMK were predicted and subsequently validated using gene chip data from our team previous study. Differentially expressed proteins (DEPs) related to the allergic constitution were also extracted based on a previous study. Pathway enrichment analysis was performed using KOBAS-i on the GWAS, RRA, WGCNA modules, DEPs, and GMK targets. P values from multi-omics datasets were combined by meta-analysis, and Bonferroni correction was applied. The significant pathways were further validated using Gene Set Enrichment Analysis (GSEA) with intervention data of GMK. The GWAS results yielded 172 genes. Four datasets AR1, AA1, AD1, and AD2 were acquired from GSE75011, GSE125916, and GSE184237. The RRA algorithm identified 19 upregulated and 20 downregulated genes. WGCNA identified 5 significant modules, with the blue and turquoise modules displaying a moderate correlation with allergies. By performing network pharmacology analysis, we identified 127 active ingredients of GMK and predicted 618 targets. Validation using gene chip data confirmed 107 GMK targets. Single-omics pathway analysis was conducted using KOBAS-i, and 39 significant pathways were identified across multiple omics datasets. GSEA analysis using GMK intervention data identified 11 of 39 significant pathways as the final key pathways associated with the allergic constitution. Through multi-omics integrated pathway analysis, we identified 11 critical pathways of allergic constitution, including TH1 and TH2 cell differentiation, TLR cascade, and TH17 cell differentiation. Identifying these pathways suggests that the observed alterations at the pathway level may play significant roles in the molecular characteristics of the allergic constitution.

Epigenetic Methylation Changes in Pregnant Women: Bisphenol Exposure and Atopic Dermatitis.

Bisphenol is a chemical substance widely used in plastic products and food containers. In this study, we observed a relationship between DNA methylation and atopic dermatitis (AD) in the peripheral blood mononuclear cells (PBMCs) of pregnant women exposed to bisphenol A (BPA) and its alternatives, bisphenol S (BPS) and bisphenol F (BPF). DNA methylation is an epigenetic mechanism that regulates gene expression, which can be altered by environmental factors, and affects the onset and progression of diseases. We found that genes belonging to the JAK-STAT and PI3K-AKT signaling pathways were hypomethylated in the blood of pregnant women exposed to bisphenols. These genes play important roles in skin barrier function and immune responses, and may influence AD. Therefore, we suggest that not only BPA, but also BPS and BPF, which are used as alternatives, can have a negative impact on AD through epigenetic mechanisms.

Association of Interleukin-17A and Interleukin-17F Gene Polymorphisms with Atopic Dermatitis in Chinese Children.

Background: Atopic dermatitis (AD) is a chronic, recurrent inflammatory disease associated with an unbalanced immune response in the upper layers of the skin tissue, mostly starting in childhood. As important factors in gene expression regulation, polymorphisms in interleukin (IL)-17A and IL-17F may be associated with the susceptibility and severity of AD. Methods: Blood samples and clinical information were obtained from 132 patients with AD and 100 healthy children. Using multiplex polymerase chain reaction and next-generation sequencing, five potential single-nucleotide polymorphisms (SNPs) of IL-17A and IL-17F were genotyped in all participants. The relationship between SNPs and susceptibility to or severity of AD was examined by analyzing haplotypes and genetic models. Results: The IL-17A rs3819025 polymorphism was substantially associated with higher AD risk in both the allele model (p = 0.03; odds ratio [OR] = 1.76; confidence interval [CI]: 1.05-2.95) and the dominant model (p = 0.04, OR = 1.85; CI: 1.03-3.33). There was no correlation between AD susceptibility and the IL-17A (rs2275913 and rs4711998) or IL-17F (rs763780 and rs12203736) SNPs (all p > 0.05). Additionally, the five IL-17A and IL-17F SNPs did not significantly differ across the mild-to-moderate and severe subgroups (all p > 0.05). Conclusions: The IL-17A/rs3819025 polymorphism was linked to the development of AD, whereas the IL-17F polymorphism was unrelated to the susceptibility to and severity of AD. The IL-17A polymorphism may provide valuable information to speculate on the susceptibility to AD in Chinese Han children.

Recent Advancements in the Atopic Dermatitis Mechanism.

Atopic dermatitis (AD) is a recurrent, chronic, inflammatory, itchy skin disorder that affects up to 20% of the pediatric population and 10% of the adult population worldwide. Onset typically occurs early in life, and although cardinal disease features are similar across all ages, different age groups and ethnicities present distinct clinical characteristics. The disease imposes a significant burden in all health-related quality of life domains, both in children and adults, and a substantial economic cost both at individual and national levels. The pathophysiology of AD includes a complex and multifaceted interplay between the impaired dysfunctional epidermal barrier, genetic predisposition, and environmental contributors, such as chemical and/or biological pollutants and allergens, in the context of dysregulated TH2 and TH17 skewed immune response. Regarding the genetic component, the loss of function mutations encoding structural proteins such as filaggrin, a fundamental epidermal protein, and the more recently identified variations in the epidermal differentiation complex are well-established determinants resulting in an impaired skin barrier in AD. More recently, epigenetic factors have facilitated AD development, including the dysbiotic skin microbiome and the effect of the external exposome, combined with dietary disorders. Notably, the interleukin (IL)-31 network, comprising several cell types, including macrophages, basophils, and the generated cytokines involved in the pathogenesis of itch in AD, has recently been explored. Unraveling the specific AD endotypes, highlighting the implicated molecular pathogenetic mechanisms of clinically relevant AD phenotypes, has emerged as a crucial step toward targeted therapies for personalized treatment in AD patients. This review aims to present state-of-the-art knowledge regarding the multifactorial and interactive pathophysiological mechanisms in AD.

No causal association between atopic dermatitis and COVID-19 outcomes: A Mendelian randomization study.

BACKGROUND: Frequent hand washing and disinfection during the corona virus disease (COVID-19) pandemic may lead to skin-related disability. The causal relationship between atopic dermatitis (AD), the most common chronic, noninfectious, inflammatory skin disease, and COVID-19 remains unclear. We used Mendelian randomization (MR) to explore the causal inference of atopic dermatitis with COVID-19 outcomes. METHODS: Genome-wide association study (GWAS) data for AD, consisting of 8383 cases and 236,162 controls of European ethnicity, were provided by the FinnGen database. The GWAS outcome data were derived from the COVID-19 Host Genetics Initiative and consisted of COVID-19 susceptibility (122,616 cases and 2,475,240 controls), hospitalization (32,519 cases and 2,062,805 controls), and very severe respiratory disease (13,769 cases and 1,072,442 controls). The inverse variance weighted with a fixed effects model (IVW (fe)) was used as the main statistical approach to assess the causality between AD and COVID-19 in this study. Several other analytical methods have also been used to complement or identify pleiotropy and heterogeneity. RESULTS: MR analysis showed no causality between AD and COVID-19 outcomes. The odds ratios (OR) were 1.00 (95% confidence interval (CI), 0.99-1.02) for susceptibility, 1.00 (95% CI, 0.96-1.04) for hospitalization, 0.97 (95% CI, 0.92-1.03) for very severe respiratory disease by the method of IVW (fe). CONCLUSION: In conclusion, we found no causal relationship between AD and COVID-19 outcomes. This study provides additional ideas for the exploration of the risk factors for COVID-19.

Integrative network analysis suggests prioritised drugs for atopic dermatitis.

BACKGROUND: Atopic dermatitis (AD) is a prevalent chronic inflammatory skin disease whose pathophysiology involves the interplay between genetic and environmental factors, ultimately leading to dysfunction of the epidermis. While several treatments are effective in symptom management, many existing therapies offer only temporary relief and often come with side effects. For this reason, the formulation of an effective therapeutic plan is challenging and there is a need for more effective and targeted treatments that address the root causes of the condition. Here, we hypothesise that modelling the complexity of the molecular buildup of the atopic dermatitis can be a concrete means to drive drug discovery. METHODS: We preprocessed, harmonised and integrated publicly available transcriptomics datasets of lesional and non-lesional skin from AD patients. We inferred co-expression network models of both AD lesional and non-lesional skin and exploited their interactional properties by integrating them with a priori knowledge in order to extrapolate a robust AD disease module. Pharmacophore-based virtual screening was then utilised to build a tailored library of compounds potentially active for AD. RESULTS: In this study, we identified a core disease module for AD, pinpointing known and unknown molecular determinants underlying the skin lesions. We identified skin- and immune-cell type signatures expressed by the disease module, and characterised the impaired cellular functions underlying the complex phenotype of atopic dermatitis. Therefore, by investigating the connectivity of genes belonging to the AD module, we prioritised novel putative biomarkers of the disease. Finally, we defined a tailored compound library by characterising the therapeutic potential of drugs targeting genes within the disease module to facilitate and tailor future drug discovery efforts towards novel pharmacological strategies for AD. CONCLUSIONS: Overall, our study reveals a core disease module providing unprecedented information about genetic, transcriptional and pharmacological relationships that foster drug discovery in atopic dermatitis.

Management of Atopy with Dupilumab and Omalizumab in CADINS Disease.

The caspase activation and recruitment domain 11 (CARD11) gene encodes a scaffold protein required for lymphocyte antigen receptor signaling. Dominant-negative, loss-of-function (LOF) pathogenic variants in CARD11 result in CARD11-associated atopy with dominant interference of NF-κB signaling (CADINS) disease. Patients with CADINS suffer with severe atopic manifestations including atopic dermatitis, food allergy, and chronic spontaneous urticaria in addition to recurrent infections and autoimmunity. We assessed the response of dupilumab in five patients and omalizumab in one patient with CADINS for the treatment of severe atopic symptoms. CARD11 mutations were validated for pathogenicity using a T cell transfection assay to assess the impact on activation-induced signaling to NF-κB. Three children and three adults with dominant-negative CARD11 LOF mutations were included. All developed atopic disease in infancy or early childhood. In five patients, atopic dermatitis was severe and recalcitrant to standard topical and systemic medications; one adult suffered from chronic spontaneous urticaria. Subcutaneous dupilumab was initiated to treat atopic dermatitis and omalizumab to treat chronic spontaneous urticaria. All six patients had rapid and sustained improvement in atopic symptoms with no complications during the follow-up period. Previous medications used to treat atopy were able to be decreased or discontinued. In conclusion, treatment with dupilumab and omalizumab for severe, refractory atopic disease in patients with CADINS appears to be effective and well tolerated in patients with CADINS with severe atopy.