Atopic dermatitis endotypes and implications for targeted therapeutics

Biomarkers and patient-related factors associated with clinical outcomes in dupilumab-treated atopic dermatitis

Background

Atopic dermatitis (AD) is a common chronic eczematous skin disease with severe pruritus. Several new therapeutic agents for AD such as dupilumab, an anti-IL-4Rα antibody, have been developed in recent years. We need to predict which agent is the best choice for each patient, but this remains difficult.

Objective

Our aim was to examine clinical background factors and baseline biomarkers that could predict the achievement of improved clinical outcomes in patients with AD treated with dupilumab.

Methods

A multicenter, prospective observational study was conducted on 110 patients with AD. The Eczema Area and Severity Index was used as an objective assessment, and the Patient-Oriented Eczema Measure and Numerical Rating Scale for Pruritus were used as patient-reported outcomes. In addition, some clinical background factors were evaluated.

Results

The achievement of an absolute Eczema Area and Severity Index of 7 or less was negatively associated with current comorbidity of food allergy and baseline serum lactate dehydrogenase (LDH) levels. There were negative associations between achievement of a Patient-Oriented Eczema Measure score of 7 or less and duration of severe AD and between achievement of an itching Numerical Rating Scale for Pruritus score of 1 or less and current comorbidity of allergic conjunctivitis or baseline serum periostin level. Furthermore, signal detection analysis showed that a baseline serum LDH level less than 328 U/L could potentially be used as a cutoff value for predicting the efficacy of dupilumab.

Conclusion

Baseline biomarkers such as LDH and periostin and clinical background factors such as current comorbidity of food allergy and a long period of severe disease may be useful indicators when choosing dupilumab for systemic treatment for AD, as they can predict the efficacy of dupilumab.

Management of Atopic Hand Dermatitis

Atopic hand dermatitis (AHD), a manifestation of atopic dermatitis, can have a profound negative effect on a patient's disease-related quality of life due to its visibility, chronic nature, and overall discomfort that it causes. AHD differs from other forms of chronic hand eczema due to its likely distinct, complex pathogenesis, which is a combination of environmental triggers, genetic predisposition, and immune dysfunction. A proper diagnosis of AHD is made through clinical evaluation and the ability to establish subtle clinical differences between AHD and other conditions. Diagnosis is the first step to a treatment plan that diverges from a one-size-fits-all approach.

The clinical, mechanistic, and social impacts of air pollution on atopic dermatitis

Atopic dermatitis (AD) is a complex disease characterized by dry, pruritic skin and significant atopic and psychological sequelae. Although AD has always been viewed as multifactorial, early research was dominated by overlapping genetic determinist views of either innate barrier defects leading to inflammation or innate inflammation eroding skin barrier function. Since 1970, however, the incidence of AD in the United States has increased at a pace that far exceeds genetic drift, thus suggesting a modern, environmental etiology. Another implicated factor is Staphylococcus aureus; however, a highly contagious microorganism is unlikely to be the primary etiology of a noncommunicable disease. Recently, the roles of the skin and gut microbiomes have received greater attention as potentially targetable drivers of AD. Here too, however, dysbiosis on a population scale would require induction by an environmental factor. In this review, we describe the evidence supporting the environmental hypothesis of AD etiology and detail the molecular mechanisms of each of the AD-relevant toxins. We also outline how a pollution-focused paradigm demands earnest engagement with environmental injustice if the field is to meaningfully address racial and geographic disparities. Identifying specific toxins and their mechanisms can also inform in-home and national mitigation strategies.

Navigating the evolving landscape of atopic dermatitis: Challenges and future opportunities: The 4th Davos declaration

The 4th Davos Declaration was developed during the Global Allergy Forum in Davos which aimed to elevate the care of patients with atopic dermatitis (AD) by uniting experts and stakeholders. The forum addressed the high prevalence of AD, with a strategic focus on advancing research, treatment, and management to meet the evolving challenges in the field. This multidisciplinary forum brought together top leaders from research, clinical practice, policy, and patient advocacy to discuss the critical aspects of AD, including neuroimmunology, environmental factors, comorbidities, and breakthroughs in prevention, diagnosis, and treatment. The discussions were geared towards fostering a collaborative approach to integrate these advancements into practical, patient-centric care. The forum underlined the mounting burden of AD, attributing it to significant environmental and lifestyle changes. It acknowledged the progress in understanding AD and in developing targeted therapies but recognized a gap in translating these innovations into clinical practice. Emphasis was placed on the need for enhanced awareness, education, and stakeholder engagement to address this gap effectively and to consider environmental and lifestyle factors in a comprehensive disease management strategy. The 4th Davos Declaration marks a significant milestone in the journey to improve care for people with AD. By promoting a holistic approach that combines research, education, and clinical application, the Forum sets a roadmap for stakeholders to collaborate to improve patient outcomes in AD, reflecting a commitment to adapt and respond to the dynamic challenges of AD in a changing world.

Clinical correlates of lifetime and current comorbidity patterns in autoimmune and inflammatory diseases

BACKGROUND

Autoimmune and inflammatory diseases (AIDs) are a heterogeneous group of disorders with diverse etiopathogenic mechanisms. This study explores the potential utility of family history, together with present and past comorbidities, in identifying distinct etiopathogenic subgroups. This approach may facilitate more accurate diagnosis, prognosis and personalized therapy.

METHODS

We performed a multiple correspondence analysis on patients' comorbidities, followed by hierarchical principal component clustering of clinical data from 48 healthy volunteers and 327 patients with at least one of 19 selected AIDs included in the TRANSIMMUNOM cross-sectional study.

RESULTS

We identified three distinct clusters characterized by: 1) the absence of comorbidities, 2) polyautoimmunity, and 3) polyinflammation. These clusters were further distinguished by specific comorbidities and biological parameters. Autoantibodies, allergies, and viral infections characterized the polyautoimmunity cluster, while older age, BMI, depression, cancer, hypertension, periodontal disease, and dyslipidemia characterized the polyinflammation cluster. Rheumatoid arthritis patients were distributed across all three clusters. They had higher DAS28 and prevalence of extra-articular manifestations when belonging to the polyinflammation and polyautoimmunity clusters, and also lower ACPA and RF seropositivity and higher pain scores within the polyinflammation cluster. We developed a model allowing to classify AID patients into comorbidity clusters.

CONCLUSIONS

In this study, we have uncovered three distinct comorbidity profiles among AID patients. These profiles suggest the presence of distinct etiopathogenic mechanisms underlying these subgroups. Validation, longitudinal stability assessment, and exploration of their impact on therapy efficacy are needed for a comprehensive understanding of their potential role in personalized medicine.

Assessment of serum levels of ischemia modified albumin and interleukin-17 in children with atopic dermatitis

BACKGROUND

Atopic dermatitis (AD) is the most prevalent chronic inflammatory skin disease in childhood. Interleukin 17 (IL17) is one of the pro-inflammatory cytokines that has an important role in the pathogenesis of many skin diseases including AD. Ischemia modified albumin (IMA) is an indicator of oxidative stress, inflammation and ischemia. The aim of the study was to assess the IL-17 and IMA serum levels in the children patients with AD in comparison to a control group. Additionally, the study seeks to examine the correlation between these biomarkers and their association with disease severity, disease stages, and other clinical characteristics.

METHODS

The case-control study enrolled two groups: (patient group: 50 children with AD) and (control group: 50 healthy age and sex-matched children). Full history was taken from all cases along with full dermatologic examination. The assessment of AD severity was conducted by using Eczema Area and Severity Index (EASI). Evaluation of IL-17 and IMA was performed by using ELISA technique.

RESULTS

There was a statistically significant elevation in the mean levels of IL-17 and IMA in patients with AD compared to the control group. A strong positive correlation was observed between IL-17 and IMA levels. Additionally, both IL-17 and IMA levels exhibited a statistically significant negative correlation with the duration of the disease and the age of the patients.

CONCLUSION

The elevated serum levels of IL17 and IMA and their positive correlation confirm that AD is a systemic inflammatory disease influenced and associated with increased oxidative stress.

Cytokine profile of the stratum corneum in atopic dermatitis lesions differs between the face and the trunk

BACKGROUND

Atopic dermatitis (AD) is a chronic inflammatory skin disease with intense pruritus. Dupilumab, an anti-IL-4 receptor alpha antibody, has been revealed to be highly effective against the symptoms of AD; however, dupilumab takes longer to improve facial dermatitis in some patients. We thus examined whether the cytokine profiles in AD lesions differ between different anatomical locations.

METHODS

Stratum corneum was collected by tape stripping from lesions of the forehead and abdomen of 24 patients with moderate to severe AD and at the same anatomical locations of 14 control subjects. These samples were then used to determine the expression profiles of Th1, Th2, and Th17 cytokines/chemokines by multiplex assay and immunocytochemistry.

RESULTS

We found that cytokines/chemokines in the stratum corneum differed in their expression between different anatomical areas in AD patients and also in healthy control subjects. The expression of Th1 and Th17 cytokines/chemokines such as IP-10, MIG, and IL-17 tended to be higher in the forehead than in the abdomen in the AD group. Regarding Th2 cytokines/chemokines, some (e.g., IL-13 and IL-33) were highly expressed in the abdomen, others (e.g., IL-4 and IL-31) were highly expressed in the forehead, and a third group (e.g., TARC and TSLP) did not differ significantly in their expression between the forehead and abdomen. These patterns of Th2 cytokines were almost identical in the stratum corneum of healthy individuals.

CONCLUSIONS

Differences in cytokine/chemokine profiles in the stratum corneum between different anatomical areas might affect the responsiveness to AD treatment.

Sensitization to latex and food allergens in atopic dermatitis patients according to ALEX2 Allergy Xplorer test

Aim of our study is to analyse the sensitisation profile to molecular components of latex and of food allergens with the use of ALEX2 Allergy Xplorer test and to compare these results with the anamnestical data after latex exposure and with the anamnestical data after exposure to food allergens in atopic dermatitis patients.

METHODS

100 patients were included in the study (49 men and 51 women with the average age 40.6 years). The specific IgE was examined with the use of ALEX2 Allergy Xplorer test. A detailed personal history of allergic reaction to latex and allergic reaction to food allergens was taken in all included patients.

RESULTS

The sensitisation to latex was recorded in 17 % of patients, majority of patients have positive results of specific IgE to Hev b 8 without clinical reaction to latex. In 7 % of patients with positive results of specific IgE to Hev b 1, Hev b 3, Hev b 5, Hev b 6.02 and Hev b 11 the contact urticaria or contact dermatitis were recorded. The latex fruit syndrome was recorded in 7 % of patients; in another 10 % of patients we recorded no clinical reaction to latex, but the positive results to molecular components of latex and the clinical symptoms after ingestion of different kinds of fruits.

CONCLUSION

The significant relation between the results of specific IgE to molecular components Hev b 3, Hev b 5 and Hev b 6.02 and the clinical reaction to latex was confirmed; these components significantly imply clinical reactivity to latex.

Updated insights into the molecular pathogenesis of canine atopic dermatitis

Atopic dermatitis (AD) is a common and chronic inflammatory skin disease with frequent relapses. The genomics revolution has greatly contributed and revolutionised our knowledge of human AD; understanding the molecular skin fingerprint of AD and associated pathogenic immune pathways has led to preclinical assessments of several novel treatments. Initial studies using microarray analysis to analyse transcriptome (gene expression) changes provided relevant insight on the inflammatory and structural changes occurring at the time of acute or chronic AD skin lesions, or after immunomodulating treatments with drugs ciclosporin and dupilumab, a monoclonal antibody anti-IL4 receptor. The studies revealed that human AD is characterised by the activation of multiple cytokine pathways (predominance of T helper cell [Th]2 with some activation of Th1, Th17 and Th22) as well as dysregulated expression of barrier components in the skin. There are several reports on the expression of different single molecular targets (e.g. interleukin [IL]-13, CCL17 and periostin) in spontaneous canine AD (cAD). However, significant studies of the transcriptome have been limited to a single microarray study analysing chronic AD skin lesions in dogs. While revealing a large number of genes differentially expressed in cAD skin, the small sample size (n = 13 dogs) and the lack of changes in key epidermal barrier and inflammatory cytokine genes in the microarrays have inhibited discussion towards specific immunological changes. This review summarises the current literature regarding the molecular mechanisms of spontaneous cAD, including the recent data regarding RNA sequencing, and compares some pathogenic aspects to the previously published data from human AD.

The role of OX40 ligand/OX40 axis signalling in atopic dermatitis

Atopic dermatitis (AD) is a heterogeneous inflammatory condition involving multiple immune pathways mediated by pathogenic T cells. OX40 ligand (OX40L) and OX40 are costimulatory immune checkpoint molecules that regulate effector and memory T-cell activity and promote sustained immune responses in multiple immunological pathways, including T helper (Th)2, Th1, Th17 and Th22. As such, OX40L/OX40 signalling between antigen-presenting cells (APCs) and activated T cells postantigen recognition promotes pathogenic T-cell proliferation and survival. Under inflammatory conditions, OX40L is upregulated on APCs, enhancing the magnitude of antigen-specific T-cell responses and secretion of proinflammatory cytokines. In AD, OX40L/OX40 signalling contributes to the amplification and chronic persistence of T-cell-mediated inflammation. Recent therapeutic success in clinical trials has highlighted the importance of the OX40L/OX40 axis as a promising target for the treatment of AD. Here, we discuss the many factors that are involved in the expression of OX40L and OX40, including the cytokine milieu, antigen presentation, the inflammatory environment in AD, and the therapeutic direction influenced by this costimulatory pathway.

Atopic dermatitis and IgE-mediated food allergy: Common biologic targets for therapy and prevention

OBJECTIVE

To highlight common mechanistic targets for the treatment of atopic dermatitis (AD) and IgE-mediated food allergy (IgE-FA) with potential to be effective for both diseases and prevent atopic progression.

DATA SOURCES

Data sources were PubMed searches or National Clinical Trials (NCT)-registered clinical trials related to AD, IgE-FA, and other atopic conditions, especially focused on the pediatric population.

STUDY SELECTIONS

Human seminal studies and/or articles published in the past decade were emphasized with reference to preclinical models when relevant. NCT-registered clinical trials were filtered by inclusion of pediatric subjects younger than 18 years with special focus on children younger than 12 years as a critical period when AD and IgE-FA diseases may often be concurrent.

RESULTS

AD and IgE-FA share several pathophysiologic features, including epithelial barrier dysfunction, innate and adaptive immune abnormalities, and microbial dysbiosis, which may be critical for the clinical progression between these diseases. Revolutionary advances in targeted biologic therapies have shown the benefit of inhibiting type 2 immune responses, using dupilumab (anti-interleukin-4Rα) or omalizumab (anti-IgE), to potentially reduce symptom burden for both diseases in pediatric populations. Although the potential for biologics to promote disease remission (AD) or sustained unresponsiveness (IgE-FA) remains unclear, the refinement of biomarkers to predict infants at risk for atopic disorders provides promise for prevention through timely intervention.

CONCLUSION

AD and IgE-FA exhibit common features that may be leveraged to develop biologic therapeutic strategies to treat both conditions and even prevent atopic progression. Future studies should be designed with consistent age stratification in the pediatric population and standardized regimens of adjuvant oral immunotherapy or dose escalation (IgE-FA) to improve cross-study interpretation.

Interleukin-1α inhibitor bermekimab in patients with atopic dermatitis: randomized and nonrandomized studies

Bermekimab is a human-derived recombinant monoclonal antibody that exhibits immunoregulatory activity by specifically blocking interleukin-1α activity. Four phase 2 studies evaluated efficacy and safety of bermekimab in patients with moderate-to-severe atopic dermatitis (AD). In addition, a novel human skin explant model was developed to assess bermekimab pharmacokinetics/pharmacodynamics and proteomic/transcriptomic effects. Study 1 (NCT03496974, N = 38) was an open-label, dose escalation study of subcutaneous bermekimab (200 mg or 400 mg). Study 2 (NCT04021862, N = 87) was a double-blind, placebo-controlled, randomized (1:1:1) study of subcutaneous bermekimab (400 mg every week (qw) or every 2 weeks) or placebo. GENESIS (NCT04791319, N = 198) was a double-blind, placebo- and active-comparator-controlled, randomized (1:1:2:2) study of placebo, subcutaneous bermekimab (350 mg or 700 mg qw), or dupilumab. LUNA (NCT04990440, N = 6) was a double-blind, placebo-controlled, randomized (4:1) study of intravenous bermekimab 800 mg qw or placebo. A novel human ex vivo skin pharmacodynamic assay supported phase 0 (NCT03953196) and phase 1 (NCT04544813) studies. In Study 1, 400 mg subcutaneous bermekimab showed improvement in efficacy assessments (e.g., ≥ 75% improvement of EASI over baseline, IGA 0/1, and worst itch); however, efficacy was not confirmed in Study 2 or GENESIS. Consequently, GENESIS and LUNA were terminated early. The novel human ex vivo skin pharmacodynamic assay demonstrated that bermekimab reduced downstream skin injury responses. Although bermekimab showed potential as an AD treatment in preclinical and early open-label trials, larger controlled studies (Study 2 and GENESIS) did not confirm those initial results.

Hydrogels: a promising therapeutic platform for inflammatory skin diseases treatment

Inflammatory skin diseases, such as psoriasis and atopic dermatitis, pose significant health challenges due to their long-lasting nature, potential for serious complications, and significant health risks, which requires treatments that are both effective and exhibit minimal side effects. Hydrogels offer an innovative solution due to their biocompatibility, tunability, controlled drug delivery capabilities, enhanced treatment adherence and minimized side effects risk. This review explores the mechanisms that guide the design of hydrogel therapeutic platforms from multiple perspectives, focusing on the components of hydrogels, their adjustable physical and chemical properties, and their interactions with cells and drugs to underscore their clinical potential. We also examine various therapeutic agents for psoriasis and atopic dermatitis that can be integrated into hydrogels, including traditional drugs, novel compounds targeting oxidative stress, small molecule drugs, biologics, and emerging therapies, offering insights into their mechanisms and advantages. Additionally, we review clinical trial data to evaluate the effectiveness and safety of hydrogel-based treatments in managing psoriasis and atopic dermatitis under complex disease conditions. Lastly, we discuss the current challenges and future opportunities for hydrogel therapeutics in treating psoriasis and atopic dermatitis, such as improving skin barrier penetration and developing multifunctional hydrogels, and highlight emerging opportunities to enhance long-term safety and stability.

IL-22 in Atopic Dermatitis

Atopic dermatitis (AD) is a prevalent and chronic inflammatory skin condition characterized by a multifaceted pathophysiology that gives rise to diverse clinical manifestations. The management of AD remains challenging due to the suboptimal efficacy of existing treatment options. Nonetheless, recent progress in elucidating the underlying mechanisms of the disease has facilitated the identification of new potential therapeutic targets and promising drug candidates. In this review, we summarize the newest data, considering multiple connections between IL-22 and AD. The presence of circulating IL-22 has been found to correlate with the severity of AD and is identified as a critical factor driving the inflammatory response associated with the condition. Elevated levels of IL-22 in patients with AD are correlated with increased proliferation of keratinocytes, alterations in the skin microbiota, and impaired epidermal barrier function. Collectively, these factors contribute to the manifestation of the characteristic symptoms observed in AD.

Langerhans cells: Central players in the pathophysiology of atopic dermatitis

Atopic dermatitis (AD) is the most common chronic inflammatory skin disease worldwide. AD is a highly complex disease with different subtypes. Many elements of AD pathophysiology have been described, but if/how they interact with each other or which mechanisms are important in which patients is still unclear. Langerhans cells (LCs) are antigen-presenting cells (APCs) in the epidermis. Depending on the context, they can act either pro- or anti-inflammatory. Many different studies have investigated LCs in the context of AD and found them to be connected to all major mechanisms of AD pathophysiology. As APCs, LCs recruit other immune cells and shape the immune response, especially adaptive immunity via polarization of T cells. As sentinel cells, LCs are primary sensors of the skin microbiome and are important for the decision of immunity versus tolerance. LCs are also involved with the integrity of the skin barrier by influencing tight junctions. Finally, LCs are important cells in the neuro-immune crosstalk in the skin. In this review, we provide an overview about the many different roles of LCs in AD. Understanding LCs might bring us closer to a more complete understanding of this highly complex disease. Potentially, modulating LCs might offer new options for targeted therapies for AD patients.

Systemic Inflammatory Proteomic Biomarkers in Atopic Dermatitis: Exploring Potential Indicators for Disease Severity

BACKGROUND

Atopic dermatitis (AD) is a chronic inflammatory cutaneous disorder, that emerges from intricate interplays among genetic predisposition, immune dysregulation, environmental factors, and compromised skin barrier. Understanding the inflammatory pathway in AD is important due to its fundamental role in the pathogenesis of AD. This study aimed to explore the diverse spectrum of proteins linked to the inflammation of AD and the relationship between systemic biomarkers and clinical severity in AD.

METHODS

We examined the blood samples from 48 patients with AD and 48 healthy controls (HCs) using the Proximity Extension Assay (Olink). Differentially expressed proteins (DEPs) were identified and Pearson correlation analysis was conducted to determine systemic proteomic biomarkers associated with severity of AD.

RESULTS

A total of 29 DEPs were significantly up-regulated and 2 DEPs were significantly down-regulated in AD compared with the HC. The MCP-4, IL-18, MCP-3, TNFRSF9, and IL-17C were the top 5 highest DEPs associated with the severity of AD.

CONCLUSION

Our study sheds light on the intricate network of inflammatory proteins in AD and their potential implications for disease severity. Our results indicate that these systemic inflammatory proteins could be valuable for assessing AD severity and enhancing our understanding of the disease's complexity and its potential management strategies.

Skin microdialysis detects distinct immunologic patterns in chronic inflammatory skin diseases

BACKGROUND

Insight into the pathophysiology of inflammatory skin diseases, especially at the proteomic level, is severely hampered by the lack of adequate in situ data.

OBJECTIVE

We characterized lesional and nonlesional skin of inflammatory skin diseases using skin microdialysis.

METHODS

Skin microdialysis samples from patients with atopic dermatitis (AD, n = 6), psoriasis vulgaris (PSO, n = 7), or prurigo nodularis (PN, n = 6), as well as healthy controls (n = 7), were subjected to proteomic and multiplex cytokine analysis. Single-cell RNA sequencing of skin biopsy specimens was used to identify the cellular origin of cytokines.

RESULTS

Among the top 20 enriched Gene Ontology (GO; geneontology.org) annotations, nicotinamide adenine dinucleotide metabolic process, regulation of secretion by cell, and pyruvate metabolic process were elevated in microdialysates from lesional AD skin compared with both nonlesional skin and controls. The top 20 enriched Kyoto Encyclopedia of Genes and Genomes (KEGG; genome.jp/kegg) pathways in these 3 groups overlapped almost completely. In contrast, nonlesional skin from patients with PSO or PN and control skin showed no overlap with lesional skin in this KEGG pathway analysis. Lesional skin from patients with PSO, but not AD or PN, showed significantly elevated protein levels of MCP-1 compared with nonlesional skin. IL-8 was elevated in lesional versus nonlesional AD and PSO skin, whereas IL-12p40 and IL-22 were higher only in lesional PSO skin. Integrated single-cell RNA sequencing data revealed identical cellular sources of these cytokines in AD, PSO, and PN.

CONCLUSION

On the basis of microdialysates, the proteomic data of lesional PSO and PN skin, but not lesional AD skin, differed significantly from those of nonlesional skin. IL-8, IL-22, MCP-1, and IL-12p40 might be suitable markers for minimally invasive molecular profiling.

Proteomic analysis of cardiovascular disease-associated proteins in Korean patients with moderate-to-severe atopic dermatitis

Background

Cardiovascular diseases (CVDs) have been associated with atopic dermatitis (AD), including in Korean patients. Previous studies on AD have primarily focused on patients of European ancestry, while the Asian endotype exhibits distinct characteristics. This study aimed to characterize the blood proteomic signature of Korean patients with moderate-to-severe AD, with an emphasis on proteins related to CVDs.

Methods

A total of 78 participants, including 39 patients with moderate-to-severe AD and 39 age- and sex-matched healthy controls, were enrolled. Blood proteomics analysis was performed using the Olink CVD II panel, which measures the expression levels of 92 proteins associated with CVDs.

Results

Unsupervised hierarchical clustering revealed 44 upregulated and 5 downregulated proteins in AD patients compared to healthy controls. Principal component analysis (PCA) effectively distinguished AD patients from healthy subjects based on the complete set of proteins or the subset of upregulated proteins. A multiple linear regression model comprising CCL17 and FGF21 showed a strong correlation with disease severity (R = 0.619). Correlation analysis identified 25 highly correlated proteins, including STK4, ITGB1BP2, and DECR1, which were newly found to be upregulated in Korean AD patients. Pathway analysis highlighted the involvement of these proteins in vascular system, inflammation, and lipid metabolism pathways.

Conclusion

The blood proteomic profile of moderate-to-severe AD patients in Korea differed from healthy controls using the CVD II panel. This study provides potential biomarkers for the AD-CVD association and insights into the pathways contributing to this relationship in the Korean population.

The Role of Collagens in Atopic Dermatitis

Atopic dermatitis (AD) is a chronic inflammatory skin disease affecting both children and adults. The clinical picture of AD manifests in typical skin lesions, such as localized eczema and dry skin, with dominant, persistent itching that leads to sleep disturbances. The pathophysiology of AD has been extensively investigated with respect to epigenetic and genetic factors, skin barrier defects, as well as immunological and microbial disorders. However, to date, the involvement of extracellular matrix (ECM) elements has received limited attention. Collagen, a major component of the ECM, may serve as a therapeutic target for the future treatment of AD. This paper summarizes the role of collagens, which are the most abundant components of the extracellular matrix in AD.

Exploring causal correlations between circulating cytokines and atopic dermatitis: a bidirectional two-sample Mendelian randomization study

Objectives

Numerous observational studies have reported associations between circulating cytokines and atopic dermatitis (AD); however, the causal relationships between them remain unclear. To explore the causal correlations and direction of causal effects between AD and levels of 91 circulating cytokines.

Methods

Two-sample Mendelian randomization (MR) analyses were conducted to examine the causal relationships between 91 circulating cytokines and AD using summary statistics from genome-wide association studies (GWAS). Reverse MR analyses were performed to investigate reverse causation. Pleiotropy and heterogeneity tests were conducted to assess the robustness of the findings. Additional transcriptome database and clinical peripheral blood mononuclear cells (PBMCs) samples were utilized to validate the results of MR analyses.

Results

Levels of interleukin (IL)-13, IL-18 Receptor 1, Tumor necrosis factor ligand superfamily member 14 (TNFSF14), TNF-related activation-induced cytokine (TRANCE), C-X-C motif chemokine (CXCL)11, IL-33, TNF-beta and CD5 were suggestively associated with the risk of AD (odds ratio, OR: 1.202, 95% CI: 1.018-1.422, p = 0.030; OR: 1.029, 95% CI: 1.029-1.157, p = 0.004; OR: 1.159, 95% CI: 1.018-1.320, p = 0.026; OR: 1.111, 95% CI: 1.016-1.214, p = 0.020; OR: 0.878, 95% CI: 0.783-0.984, p = 0.025; OR: 0.809, 95% CI: 0.661-0.991, p = 0.041; OR: 0.945, 95% CI: 0.896-0.997, p = 0.038; OR: 0.764, 95% CI: 0.652-0.895, p = 8.26e-04). In addition, levels of cytokines including Axin-1, CXCL5, CXCL10, Oncostatin-M (OSM), Sulfotransferase 1A1 (SULT1A1) and TNFSF14 were suggested to be consequences of AD (Beta: -0.080, p = 0.016; Beta: -0.062, p = 0.036; Beta: -0.066, p = 0.049; Beta: -0.073, p = 0.013; Beta: -0.089, p = 0.008; Beta: -0.079, p = 0.031). IL-13, IL-18R1, TNFSF14, and TRANCE were upregulated in both lesional skin biopsies and PBMCs from AD patients.

Conclusion

The study indicates that several cytokines, including IL-13, IL-18R1, TNFSF14, TRANCE, CXCL11, IL-33, TNF-beta, and CD5, are upstream of AD development, whereas a few circulating cytokines are potentially downstream in the development of AD.

Race science without racists: how bigoted paradigms persist in allergy research

In the wake of the murder of George Floyd and the massacre in Buffalo, the editorial boards of the prominent scientific publication companies formally apologized for their journals' historical role in advancing race science and promised to improve their standards. However, flowery commentaries cannot undo the consistent pattern of endorsing biologic differences between ethnic groups, even when discussing diseases or traits that are not considered politically charged. In this report, an exemplar is made of a recent publication claiming to identify phenotypes of atopic dermatitis that are distinct between European Americans, Asians, and African Americans. The insufficiency of the evidence and logic underlying these claims are discussed. Although devoid of malice, numerous publications continue to demonstrate how claims of biological differences between races is mainstreamed in modern scientific publications. Overall, the goal of this work is to challenge the scientific community, particularly the publication companies, to evaluate how assumptions of innate biologic disadvantage have clouded assessments of racial disparities in disease beyond the topics that are more stereotypical of race science.

Paradoxical Psoriasis: An Updated Review of Clinical Features, Pathogenesis, and Treatment Options

The definition of paradoxical psoriasis (PP) encompasses 2 main scenarios, namely, (i) new-onset psoriasis in patients treated for a different disease and (ii) worsening as well as phenotypical change of pre-existing psoriasis. Originally restricted to the appearance of an untoward psoriasiform reaction under TNF inhibitors, the term has gained new meaning, with the progressive observation of psoriasis-like eruptions also with other medications. Although the conceptual framework of PP has expanded, a molecular and clinicotherapeutic classification is still lacking. In addition, a certain degree of confusion surrounds the correct terminology to indicate these eruptions. In this paper, evidence on the epidemiology, clinical features, pathogenesis, and treatment of PP is reviewed, providing a perspective on possible pathogenesis-driven therapeutic approaches.

Atopic Dermatitis Complicated by Recurrent Eczema Herpeticum Is Characterized by Multiple, Concurrent Epidermal Inflammatory Endotypes

A subgroup of patients with atopic dermatitis (AD) suffers from recurrent, disseminated herpes simplex virus skin infection, termed eczema herpeticum. To determine the transcriptional mechanisms of the skin and immune system pathobiology that underlie development of AD with eczema herpeticum (ADEH), we performed RNA-sequencing analysis of nonlesional skin (epidermis, dermis) from AD patients with and without a history of ADEH (ADEH+, n = 15; ADEH-, n = 13) along with healthy controls (n = 15). We also performed RNA sequencing on participants' plasmacytoid dendritic cells infected in vitro with herpes simplex virus 1. ADEH+ patients exhibited dysregulated gene expression, limited in the dermis (14 differentially expressed genes) and more widespread in the epidermis (129 differentially expressed genes). ADEH+-upregulated epidermal differentially expressed genes were enriched in type 2 cytokine (IL4R , CCL22, CRLF2, IL7R), interferon (CXCL10, ICAM1, IFI44, IRF7), and IL-36γ (IL36G) inflammatory gene pathways. All ADEH+ participants exhibited type 2 cytokine and inteferon endotypes, and 87% were IL36G-high. In contrast, these endotypes were more variably expressed among ADEH- participants. ADEH+ skin also had dysregulated epidermal differentiation complex gene expression of the late-cornified envelope, S100A, and small proline-rich gene families, which are involved in skin barrier function and antimicrobial activities. Plasmacytoid dendritic cell transcriptional responses to herpes simplex virus 1 infection were unaltered by ADEH status. The study concluded that the pathobiology underlying ADEH+ risk is associated with a unique, multifaceted epidermal inflammation that accompanies dysregulation of epidermal differentiation complex genes. These findings will help direct future studies that define how these inflammatory patterns may drive risk of eczema herpeticum in AD.

Paradoxical Psoriasis

Cytokine blocking therapies have revolutionized the management of psoriasis and atopic dermatitis but can lead to the development of paradoxic psoriasis (PP). Patients treated with biologics should be closely monitored for the development of PP and other paradoxical eruptions (including inflammatory joint disease, inflammatory bowel disease, eczematous eruptions, lupus like eruptions, sarcoidal eruptions, and others) and occasionally the development of cutaneous T-cell lymphoma. Further understanding the immunologic mechanism of these processes will ultimately drive our understanding of and ability to predict and manage PPs.

Biologic and small-molecule therapy for treating moderate to severe atopic dermatitis: Mechanistic considerations

Atopic dermatitis (AD) is a complex and heterogeneous skin disease for which achieving complete clinical clearance for most patients has proven challenging through single cytokine inhibition. Current studies integrate biomarkers and evaluate their role in AD, aiming to advance our understanding of the diverse molecular profiles implicated. Although traditionally characterized as a TH2-driven disease, extensive research has recently revealed the involvement of TH1, TH17, and TH22 immune pathways as well as the interplay of pivotal immune molecules, such as OX40, OX40 ligand (OX40L), thymic stromal lymphopoietin, and IL-33. This review explores the mechanistic effects of treatments for AD, focusing on mAbs and Janus kinase inhibitors. It describes how these treatments modulate immune pathways and examines their impact on key inflammatory and barrier biomarkers.

Integrating patients in time series clinical transcriptomics data

MOTIVATION

Analysis of time series transcriptomics data from clinical trials is challenging. Such studies usually profile very few time points from several individuals with varying response patterns and dynamics. Current methods for these datasets are mainly based on linear, global orderings using visit times which do not account for the varying response rates and subgroups within a patient cohort.

RESULTS

We developed a new method that utilizes multi-commodity flow algorithms for trajectory inference in large scale clinical studies. Recovered trajectories satisfy individual-based timing restrictions while integrating data from multiple patients. Testing the method on multiple drug datasets demonstrated an improved performance compared to prior approaches suggested for this task, while identifying novel disease subtypes that correspond to heterogeneous patient response patterns.

AVAILABILITY AND IMPLEMENTATION

The source code and instructions to download the data have been deposited on GitHub at https://github.com/euxhenh/Truffle.

Prolyl Endopeptidase Is Involved in Filaggrinolysis and Cornification

FLG is a well-known biomarker of atopic dermatitis and skin dryness. Its full proteolysis (or filaggrinolysis) produces the major constituents of the natural moisturizing factor. Some proteases/peptidases remain to be identified in this multistep process. Mining 16 omics analyses, we identified prolyl endopeptidase (PREP) as a candidate peptidase. Indirect immunofluorescence and confocal analysis demonstrated its localization in the granular and deep cornified layers, where it colocalized with FLG. Tandem mass spectroscopy and fluorescent quenching activity assays showed that PREP cleaved several synthetic peptides derived from the FLG sequence, at the carboxyl side of an internal proline. Deimination of these peptides increased PREP enzymatic efficiency. Specific inhibition of PREP in reconstructed human epidermis using benzyloxycarbonyl-pro-prolinal induced the accumulation of FLG monomers. Downregulation of PREP expression in reconstructed human epidermis using RNA interference confirmed the impact of PREP on FLG metabolism and highlighted a more general role of PREP in keratinocyte differentiation. Indeed, quantitative global proteomic, western blotting, and RT-qPCR analyses showed a strong reduction in the expression of bleomycin hydrolase, known to be involved in filaggrinolysis, and of several other actors of cornification such as loricrin. Consequently, at the functional level, the transepidermal electric resistance was drastically reduced.

Characterization of High and Low IFNG-Expressing Subgroups in Atopic Dermatitis

Atopic dermatitis (AD) is one of the most common chronic inflammatory skin diseases, with an increasing number of targeted therapies available. While biologics to treat AD exclusively target the key cytokines of type 2 immunity, Janus kinase inhibitors target a broad variety of cytokines, including IFN-γ. To better stratify patients for optimal treatment outcomes, the identification and characterization of subgroups, especially with regard to their IFNG expression, is of great relevance, as the role of IFNG in AD has not yet been fully clarified. This study aims to define AD subgroups based on their lesional IFNG expression and to characterize them based on their gene expression, T cell secretome and clinical attributes. RNA from the lesional and non-lesional biopsies of 48 AD patients was analyzed by RNA sequencing. Based on IFNG gene expression and the release of IFN-γ by lesional T cells, this cohort was categorized into three IFNG groups (high, medium, and low) using unsupervised clustering. The low IFNG group showed features of extrinsic AD with a higher prevalence of atopic comorbidities and impaired epidermal lipid synthesis. In contrast, patients in the high IFNG group had a higher average age and an activation of additional pro-inflammatory pathways. On the cellular level, higher amounts of M1 macrophages and natural killer cell signaling were detected in the high IFNG group compared to the low IFNG group by a deconvolution algorithm. However, both groups shared a common dupilumab response gene signature, indicating that type 2 immunity is the dominant immune shift in both subgroups. In summary, high and low IFNG subgroups correspond to intrinsic and extrinsic AD classifications and might be considered in the future for evaluating therapeutic efficacy or non-responders.

Skin, gut, and lung barrier: Physiological interface and target of intervention for preventing and treating allergic diseases

The epithelial barriers of the skin, gut, and respiratory tract are critical interfaces between the environment and the host, and they orchestrate both homeostatic and pathogenic immune responses. The mechanisms underlying epithelial barrier dysfunction in allergic and inflammatory conditions, such as atopic dermatitis, food allergy, eosinophilic oesophagitis, allergic rhinitis, chronic rhinosinusitis, and asthma, are complex and influenced by the exposome, microbiome, individual genetics, and epigenetics. Here, we review the role of the epithelial barriers of the skin, digestive tract, and airways in maintaining homeostasis, how they influence the occurrence and progression of allergic and inflammatory conditions, how current treatments target the epithelium to improve symptoms of these disorders, and what the unmet needs are in the identification and treatment of epithelial disorders.

Treatment of atopic dermatitis: Recently approved drugs and advanced clinical development programs

Atopic dermatitis (AD) represents the most common skin disease characterized by heterogeneous endophenotypes and a high disease burden. In Europe, six new systemic therapies for AD have been approved: the biologics dupilumab (anti-interleukin-4 receptor (IL-4R) α in 2017), tralokinumab (anti-IL-13 in 2021), lebrikizumab (anti-IL-13 in 2023), and the oral janus kinase (JAK) inhibitors (JAKi) targeting JAK1/2 (baricitinib in 2020 in the EU) or JAK1 (upadacitinib in 2021 and abrocitinib in 2022). Herein, we give an update on new approvals, long-term safety, and efficacy. Upadacitinib and abrocitinib have the highest short-term efficacy among the approved systemic therapies. In responders, dupilumab and tralokinumab catch up regarding long-term efficacy and incremental clinical benefit within continuous use. Recently, the European Medicines Agency has released recommendations for the use of JAKi in patients at risk (cardiovascular and thromboembolic diseases, malignancies, (former) smoking, and age ≥65 years). Furthermore, we give an overview on emerging therapies currently in Phase III trials. Among the topical therapies, tapinarof (aryl hydrocarbon receptor), ruxolitinib (JAK1/2i), delgocitinib (pan-JAKi), asivatrep (anti-transient receptor potential vanilloid), and phosphodiesterase-4-inhibitors (roflumilast, difamilast) are discussed. Among systemic therapies, current data on cord-blood-derived mesenchymal stem cells, CM310 (anti IL-4Rα), nemolizumab (anti-IL-31RA), anti-OX40/OX40L-antibodies, neurokinin-receptor-1-antagonists, and difelikefalin (κ-opioid-R) are reported.

Mapping the immune cell landscape of severe atopic dermatitis by single-cell RNA-seq

BACKGROUND

Efforts to profile atopic dermatitis (AD) tissues have intensified, yet comprehensive analysis of systemic immune landscapes in severe AD remains crucial.

METHODS

Employing single-cell RNA sequencing, we analyzed over 300,000 peripheral blood mononuclear cells from 12 severe AD patients (Eczema area and severity index (EASI) > 21) and six healthy controls.

RESULTS

Results revealed significant immune cell shifts in AD patients, including increased Th2 cell abundance, reduced NK cell clusters with compromised cytotoxicity, and correlated Type 2 innate lymphoid cell proportions with disease severity. Moreover, unique monocyte clusters reflecting activated innate immunity emerged in very severe AD (EASI > 30). While overall dendritic cells (DCs) counts decreased, a distinct Th2-priming subset termed "Th2_DC" correlated strongly with disease severity, validated across skin tissue data, and flow cytometry with additional independent severe AD samples. Beyond the recognized role of Th2 adaptive immunity, our findings highlight significant innate immune cell alterations in severe AD, implicating their roles in disease pathogenesis and therapeutic potentials.

CONCLUSION

Apart from the widely recognized role of Th2 adaptive immunity in AD pathogenesis, alterations in innate immune cells and impaired cytotoxic cells have also been observed in severe AD. The impact of these alterations on disease pathogenesis and the effectiveness of potential therapeutic targets requires further investigation.

Atopic dermatitis: treatment and innovations in immunotherapy

Atopic dermatitis (AD) is a common inflammatory skin disease characterized by itching and skin barrier dysfunction. Moderate to severe AD is often refractory to first-line topical treatments, and systemic immunosuppressants have been shown to be effective but have significant adverse effects. The paucity of basic treatments has contributed to the development of targeted topical and systemic immunotherapies based on the use of small molecules and biologic drugs which can directly interact with AD pathogenetic pathways. They represent a new era of therapeutic innovation. Additional new treatments are desirable since AD is a heterogeneous disease marked by different immunological phenotypes. This manuscript will review the mechanism of action, safety profile, and efficacy of promising new systemic immunological treatments for AD. Since moderate to severe AD can result in poor quality of life, the development of targeted and well-tolerated immunomodulators is a crucial purpose. The introduction of new pharmacological agents may offer new therapeutic options. However, there is the need to evaluate how "narrow-acting" agents, such as individual interleukin inhibitors, will perform under the safety and efficacy profiles compared with "broad-acting" agents, such as JAK inhibitors.

Monoclonal antibodies for moderate-to-severe atopic dermatitis: a look at phase III and beyond

INTRODUCTION

The understanding of atopic dermatitis (AD) pathogenesis has rapidly expanded in recent years, catalyzing the development of new targeted monoclonal antibody treatments for AD.

AREAS COVERED

This review aims to summarize the latest clinical and molecular data about monoclonal antibodies that are in later stages of development for AD, either in Phase 3 trials or in the pharmacopoeia for up to 5 years, highlighting the biologic underpinning of each drug's mechanism of action and the potential modulation of the AD immune profile.

EXPERT OPINION

The therapeutic pipeline of AD treatments is speedily progressing, introducing the potential for a personalized medical approach in the near future. Understanding how targeting pathogenic players in AD modifies disease progression and symptomatology is key in improving therapeutic choices for patients and identifying ideal patient candidates.

Characterization of patients with atopic dermatitis based on flare patterns and severity of disease: A Danish population-based study

BACKGROUND

Flare patterns are not routinely considered in the severity classification or in clinical decision-making of atopic dermatitis (AD), but frequent or severe flares may contribute considerably to the disease burden.

OBJECTIVES

To characterize patients with AD in relation to their flare pattern and compare flare patterns to disease severity, life quality and treatment satisfaction.

METHODS

Patients with AD from the Danish Skin Cohort were included if they had active AD with and available data on number of flare-ups within the last 12 months. Categorical variables were presented as frequencies and percentages, whereas numerical variables were presented as median and interquartile ranges (IQR). Between-group differences were tested with chi-squared tests.

RESULTS

A total of 1557 patients were included, with 57 reporting 0 flares, 698 (1-5 flares), 324 (6-10 flares) and 478 reporting >10 flares during the past 12 months. Both the severity measured by PO-SCORAD and the impairment of life quality measured by DLQI were higher among patients with more flares (median [IQR] PO-SCORAD: 13.0 [5.6-22.3], 29.7 [20.8-40.6], 36.3 [26.7-47.6]and 42.9 [30.7-55.6], respectively for the four flares strata, and median [IQR] DLQI: 1.0 [0.0-2.0], 3.0 [1.0-7.0], 4.0 [1.8-9.0] and 7.0 [3.0-11.0]). Satisfaction with the current treatment was generally higher among patients with no flares. However, 36.8%, 24.6% and 23.7% of patients with 1-5, 6-10 and >10 flares reported being extremely or very satisfied with their current treatment.

CONCLUSIONS

Patients with many flares often report a higher severity and impairment of life quality compared to patients with fewer flares. Information on flaring could benefit treatment decisions, thereby decreasing undertreatment of patients with mild AD but severe flaring.

Type-2 immunity associated with type-1 related skin inflammatory diseases: friend or foe?

Chronic inflammatory skin diseases are multifactorial diseases that combine genetic predisposition, environmental triggers, and metabolic disturbances associated with abnormal immune responses. From an immunological perspective, the better understanding of their physiopathology has demonstrated a large complex network of immune cell subsets and related cytokines that interact with both epidermal and dermal cells. For example, in type-1-associated diseases such as alopecia areata, vitiligo, and localized scleroderma, recent evidence suggests the presence of a type-2 inflammation that is well known in atopic dermatitis. Whether this type-2 immune response has a protective or detrimental impact on the development and chronicity of these diseases remains to be fully elucidated, highlighting the need to better understand its involvement for the management of patients. This mini-review explores recent insights regarding the potential role of type-2-related immunity in alopecia areata, vitiligo, and localized scleroderma.

The Role of OX40-OX40L Axis in the Pathogenesis of Atopic Dermatitis

OX40 is a co-stimulatory immune checkpoint molecule that promotes the activation and the effector function of T lymphocytes through interaction with its ligand (OX40L) on antigen-presenting cells. OX40-OX40L axis plays a crucial role in Th1 and Th2 cell expansion, particularly during the late phases or long-lasting response. Atopic dermatitis is characterized by an immune dysregulation of Th2 activity and by an overproduction of proinflammatory cytokines such as interleukin (IL)-4 and IL-13. Other molecules involved in its pathogenesis include thymic stromal lymphopoietin, IL-33, and IL-25, which contribute to the promotion of OX40L expression on dendritic cells. Lesional skin in atopic dermatitis exhibits a higher level of OX40L+-presenting cells compared with other dermatologic diseases or normal skin. Recent clinical trials using antagonizing anti-OX40 or anti-OX40L antibodies have shown symptom improvement and cutaneous manifestation alleviation in patients with atopic dermatitis. These findings suggest the relevance of the OX40-OX40L axis in atopic dermatitis pathogenesis.

Propionate alleviates itch in murine models of atopic dermatitis by modulating sensory TRP channels of dorsal root ganglion

BACKGROUND

Itch is the most common symptom of atopic dermatitis (AD) and significantly decreases the quality of life. Skin microbiome is involved in AD pathogenesis, whereas its role in the regulation of itch remains elusive. In this study, we aimed to investigate the effects of skin microbial metabolite propionate on acute and chronic pruritus and to explore the mechanism.

METHODS

Using various mouse models of itch, the roles of propionate were explored by behavioral tests and histopathology/immunofluorescent analysis. Primary-cultured dorsal root ganglion neurons and HEK293 cells expressing recombinant human TRP channels were utilized for in vitro calcium imaging/in vivo miniature two-photon imaging in combination with electrophysiology and molecular docking approaches for investigation of the mechanism.

RESULTS

Propionate significantly alleviated itch and alloknesis in various mouse models of pruritus and AD and decreased the density of intraepidermal nerve fibers. Propionate reduced the responsiveness of dorsal root ganglion neurons to pruritogens in vitro, attenuated the hyper-excitability in sensory neurons in MC903-induced AD model, and inhibited capsaicin-evoked hTRPV1 currents (IC50 = 20.08 ± 1.11 μM) via interacting with the vanilloid binding site. Propionate also decreased the secretion of calcitonin gene-related peptide by nerves in MC903-induced AD mouse model, which further attenuated itch and skin inflammation.

CONCLUSION

Our study revealed a protective effect of propionate against persistent itch through direct modulation of sensory TRP channels and neuropeptide production in neurons. Regulation of itch via the skin microbiome might be a novel strategy for the treatment of AD.

OX40 in the Pathogenesis of Atopic Dermatitis-A New Therapeutic Target

Atopic dermatitis (AD) is a chronic, heterogeneous, inflammatory disease characterized by skin lesions, pruritus, and pain. Patients with moderate-to-severe AD experience chronic symptoms, intensified by unpredictable flares, and often have comorbidities and secondary complications, which can result in significant clinical burden that impacts the patient's overall quality of life. The complex interplay of immune dysregulation and skin barrier disruption drives AD pathogenesis, of which T-cell-dependent inflammation plays a critical role in patients with AD. Despite new targeted therapies, many patients with moderate-to-severe AD fail to achieve or sustain their individual treatment goals and/or may not be suitable for or tolerate these therapies. There remains a need for a novel, efficacious, well-tolerated therapeutic option that can deliver durable benefits across a heterogeneous AD patient population. Expression of OX40 [tumor necrosis factor receptor superfamily, member 4 (TNFRSF4)], a prominent T-cell co-stimulatory molecule, and its ligand [OX40L; tumor necrosis factor superfamily, member 4 (TNFSF4)] is increased in AD. As the OX40 pathway is critical for expansion, differentiation, and survival of effector and memory T cells, its targeting might be a promising therapeutic approach to provide sustained inhibition of pathogenic T cells and associated inflammation and broad disease control. Antibodies against OX40 [rocatinlimab (AMG 451/KHK4083) and telazorlimab (GBR 830)] or OX40L [amlitelimab (KY1005)] have shown promising results in early-phase clinical studies of moderate-to-severe AD, highlighting the importance of OX40 signaling as a new therapeutic target in AD.

Effect of abrocitinib on skin biomarkers in patients with moderate-to-severe atopic dermatitis

BACKGROUND

This is the first report on the effects of abrocitinib, a Janus kinase 1-selective inhibitor, on the expression of skin biomarkers in patients with moderate-to-severe atopic dermatitis (AD).

METHODS

JADE MOA (NCT03915496) was a double-blind Phase 2a trial. Adults were randomly assigned 1:1:1 to receive monotherapy with once-daily abrocitinib 200 mg, abrocitinib 100 mg, or placebo for 12 weeks. The primary endpoint was change from baseline in markers of inflammation (matrix metalloproteinase [MMP]-12), epidermal hyperplasia (keratin-16 [KRT16]), T-helper 2 (Th2) immune response (C-C motif chemokine ligand [CCL]17, CCL18, and CCL26), and Th22 immune response (S100 calcium binding protein A8, A9, and A12 [S100A8, S100A9, and S100A12]) in skin through 12 weeks.

RESULTS

A total of 46 patients received abrocitinib 200 mg (n = 14), abrocitinib 100 mg (n = 16), or placebo (n = 16). Abrocitinib improved AD clinical signs and reduced itch. Gene expression of MMP-12, KRT16, S100A8, S100A9, and S100A12 was significantly decreased from baseline with abrocitinib 200 mg (at Weeks 2, 4, and 12) and abrocitinib 100 mg (at Weeks 4 and 12) in a dose-dependent manner. Abrocitinib 200 mg resulted in significant decreases from baseline in CCL17 expression at Week 12 and CCL18 expression at Weeks 2, 4, and 12; no significant decreases were observed for CCL26.

CONCLUSIONS

Alongside improvements in clinical signs and symptoms of AD, 12 weeks of abrocitinib treatment resulted in downregulation of genes associated with inflammation, epidermal hyperplasia, and Th2 and Th22 immune responses in the skin of patients with moderate-to-severe AD.

Efficacy and Safety of Crisaborole Ointment 2% in Chinese Patients Aged ≥ 2 Years with Mild to Moderate Atopic Dermatitis

INTRODUCTION

Atopic dermatitis (AD) is a chronic immuno-inflammatory skin disease. Crisaborole ointment, 2%, is a nonsteroidal phosphodiesterase 4 inhibitor approved for the treatment of mild to moderate AD. This post hoc analysis assesses the efficacy and safety of crisaborole in Chinese patients aged ≥ 2 years with mild to moderate AD.

METHODS

We evaluated the efficacy and safety of crisaborole in Chinese patients from the vehicle-controlled, phase 3 CrisADe CLEAR study. Patients were randomly assigned 2:1 to receive crisaborole or vehicle twice daily, respectively, for 28 days. The primary endpoint was percent change from baseline in Eczema Area and Severity Index (EASI) total score at day 29. Key secondary endpoints were improvement in Investigator's Static Global Assessment (ISGA), ISGA success, and change from baseline in weekly average Peak Pruritus Numerical Rating Scale (PP-NRS) score. Adverse events were documented.

RESULTS

Of 391 patients in the overall study, 237 were from China, 157 assigned to crisaborole and 80 assigned to vehicle. A greater reduction in percent change from baseline in EASI total score at day 29 was shown in the crisaborole vs. vehicle group (least squares mean [LSM]: -66.34 [95% (confidence interval) CI -71.55 to -61.12] vs. -50.18 [95% CI -58.02 to -42.34]). Response rates for achievement of ISGA improvement (43.2% [95% CI 35.4-51.1] vs. 33.4% [95% CI 22.5-44.2]) and ISGA success (31.7% [95% CI 24.3-39.0] vs. 21.5% [95% CI 12.1-30.9]) at day 29 were higher in the crisaborole vs. vehicle group. A greater reduction in change from baseline in weekly average PP-NRS score at week 4 was observed in the crisaborole vs. vehicle group (LSM: -1.98 [95% CI -2.34 to -1.62] vs. -1.08 [95% CI -1.63 to -0.53]). No new safety signals were observed.

CONCLUSION

Crisaborole was effective and well tolerated in Chinese patients aged ≥ 2 years with mild to moderate AD.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT04360187.

Proteomic alterations in patients with atopic dermatitis

INTRODUCTION

Atopic Dermatitis (AD) is the most common inflammatory skin disease with a complex and multifactorial pathogenesis. The use of proteomics in understanding AD has yielded the discovery of novel biomarkers and may further expand therapeutic options.

AREAS COVERED

This review summarizes the most recent proteomic studies and the methodologies used in AD. It describes novel biomarkers that may monitor disease course and therapeutic response. The review also highlights skin and blood biomarkers characterizing different AD phenotypes and differentiates AD from other inflammatory skin disorders. A literature search was conducted by querying Scopus, Google Scholar, Pubmed/Medline, and Clinicaltrials.gov up to June 2023.

EXPERT OPINION

The integration of proteomics into research efforts in atopic dermatitis has broadened our understanding of the molecular profile of AD through the discovery of new biomarkers. In addition, proteomics may contribute to the development of targeted treatments ultimately improving personalized medicine. An increasing number of studies are utilizing proteomics to explore this heterogeneous disease.

Distinct T cell signatures are associated with Staphylococcus aureus skin infection in pediatric atopic dermatitis

Atopic dermatitis (AD) is an inflammatory skin condition with a childhood prevalence of up to 25%. Microbial dysbiosis is characteristic of AD, with Staphylococcus aureus the most frequent pathogen associated with disease flares and increasingly implicated in disease pathogenesis. Therapeutics to mitigate the effects of S. aureus have had limited efficacy and S. aureus-associated temporal disease flares are synonymous with AD. An alternative approach is an anti-S. aureus vaccine, tailored to AD. Experimental vaccines have highlighted the importance of T cells in conferring protective anti-S. aureus responses; however, correlates of T cell immunity against S. aureus in AD have not been identified. We identify a systemic and cutaneous immunological signature associated with S. aureus skin infection (ADS.aureus) in a pediatric AD cohort, using a combined Bayesian multinomial analysis. ADS.aureus was most highly associated with elevated cutaneous chemokines IP10 and TARC, which preferentially direct Th1 and Th2 cells to skin. Systemic CD4+ and CD8+ T cells, except for Th2 cells, were suppressed in ADS.aureus, particularly circulating Th1, memory IL-10+ T cells, and skin-homing memory Th17 cells. Systemic γδ T cell expansion in ADS.aureus was also observed. This study suggests that augmentation of protective T cell subsets is a potential therapeutic strategy in the management of S. aureus in AD.

Comprehensive plasma cytokine and chemokine profiling in prurigo nodularis reveals endotypes in Type 2 inflammation

Prurigo nodularis (PN) is a chronic inflammatory skin disease that is associated with variability in peripheral blood eosinophil levels and response to T-helper 2 targeted therapies (Th2). Our objective was to determine whether circulating immune profiles with respect to type 2 inflammation differ by race and peripheral blood eosinophil count. Plasma from 56 PN patients and 13 matched healthy controls was assayed for 54 inflammatory biomarkers. We compared biomarker levels between PN and HCs, among PN patients based on absolute eosinophil count, and across racial groups in PN. Eleven biomarkers were elevated in PN versus HCs including interleukin (IL)-12/IL-23p40, tumor necrosis factor-alpha (TNF-α), Thymic stromal lymphopoietin (TSLP), and macrophage-derived chemokine (MDC/CCL22). Additionally, PN patients with AEC > 0.3 K cells/μL had higher Th2 markers (eotaxin, eotaxin-3, TSLP, MCP-4/CCL13), and African American PN patients had lower eosinophils, eotaxin, and eotaxin-3 versus Caucasian and Asian PN patients (p < 0.05 for all). Dupilumab responders had higher AEC (p < 0.01), were more likely to be Caucasian (p = 0.02) or Asian (p = 0.05) compared to African Americans, and more often had a history of atopy (p = 0.08). This study suggests that blood AEC > 0.3 K and Asian and Caucasian races are associated with Th2 skewed circulating immune profiles and response to Th2 targeted therapies.

Dupilumab-associated head and neck dermatitis shows a pronounced type 22 immune signature mediated by oligoclonally expanded T cells

Dupilumab, an IL4R-blocking antibody, has shown clinical efficacy for atopic dermatitis (AD) treatment. In addition to conjunctivitis/blepharitis, the de novo appearance of head/neck dermatitis is now recognized as a distinct side effect, occurring in up to 10% of patients. Histopathological features distinct from AD suggest a drug effect, but exact underlying mechanisms remain unknown. We profiled punch biopsies from dupilumab-associated head and neck dermatitis (DAHND) by using single-cell RNA sequencing and compared data with untreated AD and healthy control skin. We show that dupilumab treatment was accompanied by normalization of IL-4/IL-13 downstream activity markers such as CCL13, CCL17, CCL18 and CCL26. By contrast, we found strong increases in type 22-associated markers (IL22, AHR) especially in oligoclonally expanded T cells, accompanied by enhanced keratinocyte activation and IL-22 receptor upregulation. Taken together, we demonstrate that dupilumab effectively dampens conventional type 2 inflammation in DAHND lesions, with concomitant hyperactivation of IL22-associated responses.

Clinical and molecular effects of oral CCR4 antagonist RPT193 in atopic dermatitis: A Phase 1 study

BACKGROUND

RPT193 is an orally administered small molecule antagonist of the human C-C motif chemokine receptor 4 (CCR4) that inhibits the migration and downstream activation of T-helper Type 2 (Th2) cells. We investigated single- and multiple-ascending doses of RPT193 in healthy subjects, and multiple doses of RPT193 in subjects with moderate-to-severe atopic dermatitis (AD).

METHODS

This was a first-in-human randomized, placebo-controlled Phase 1a/1b monotherapy study (NCT04271514) to evaluate the safety, tolerability, pharmacokinetics, pharmacodynamics, and CCR4 surface receptor occupancy in eligible healthy subjects and subjects with moderate-to-severe AD. Clinical efficacy and skin biomarker effects of RPT193 monotherapy were assessed as exploratory endpoints in AD subjects.

RESULTS

In healthy (n = 72) and AD subjects (n = 31), once-daily RPT193 treatment was generally well tolerated, with no serious adverse events reported and all treatment-emergent adverse events reported as mild/moderate. In AD subjects, numerically greater improvements in clinical efficacy endpoints were observed with RPT193 monotherapy versus placebo up to the end of the treatment period (Day 29), with statistically significant improvement, compared to Day 29 and placebo, observed 2 weeks after the end of treatment (Day 43) on several endpoints (p < .05). Moreover, significant changes in the transcriptional profile were seen in skin biopsies of RPT193-treated versus placebo-treated subjects at Day 29, which were also significantly correlated with improvements in clinical efficacy measures.

CONCLUSIONS

To our knowledge, this is the first clinical study with an oral CCR4 antagonist that showed clinical improvement coupled with modulation of the cutaneous transcriptomic profile in an inflammatory skin disease.

Baricitinib treatment rapidly improves the four signs of atopic dermatitis assessed by Eczema Area and Severity Index (EASI) clinical subscores

BACKGROUND

Baricitinib treatment in adults with moderate-to-severe atopic dermatitis (AD) has demonstrated rapid improvements in itch as well as AD sign severity and affected body surface area as assessed by the Eczema Area and Severity Index (EASI) total score, whether administered as monotherapy or in combination with topical corticosteroids (TCS). As EASI clinical signs differ in time course and associated antecedents, the effects of baricitinib on each individual clinical sign are of interest.

OBJECTIVES

In this post hoc analysis, we aimed to investigate the effects of baricitinib on individual EASI subscores, namely excoriation, oedema/papulation, erythema and lichenification, in both monotherapy and TCS combination therapy trials.

METHODS

We analysed the percent change from baseline in individual EASI subscores from three phase-III, double-blind, 16-week trials of baricitinib in monotherapy (BREEZE-AD1/BREEZE-AD2) and TCS combination therapy (BREEZE-AD7) cohorts via mixed model repeated measures (MMRM).

RESULTS

Baricitinib 4 mg showed rapid and sustained improvements in all four clinical signs in both cohorts. Significant effects emerged at week 1 for excoriation, oedema/papulation and erythema scores in monotherapy (p < 0.001) and TCS combination therapy (p < 0.001, p < 0.01, p < 0.001), plateaued at week 4, and remained significant versus placebo through week 16. The effect on lichenification scores also emerged early, at week 1 in monotherapy (p < 0.05) and week 2 in combination therapy (p < 0.001), with scores continuously improving without a clear plateau. Effect magnitude was highest in excoriation scores, exhibiting near-maximal reduction in week 1 of monotherapy and remaining highest across all timepoints in combination therapy.

CONCLUSIONS

Rapid and sustained improvements were observed across clinical signs of inflammation and particularly on excoriation following baricitinib treatment. Our findings suggest that selective inhibition of janus kinases 1 and 2 leads to rapid and sustained control of skin inflammation, and that rapid reductions in itch translate into early disruption of the itch-scratch cycle.

Tape Stripping - Searching for Minimally Invasive Biomarkers in Atopic Dermatitis

Atopic dermatitis (AD) is nowadays entering a new era of more targeted treatments. However, to make personalized medicine, which we are currently striving for, a reality, a reliable set of validated biomarkers is needed. The most practical seem to be biomarkers that can be obtained easily and minimally invasively. Tape stripping (TS) is a method that provides such an opportunity. This review summarizes the potential biomarkers of AD identified by the minimally invasive TS method. Thymic stromal lymphopoietin (TSLP), interleukin (IL)-13, CC chemokine ligand 17 (CCL17)/thymus and activation-regulated chemokine (TARC) and stratum corneum (SC) lipids can be used as predictive biomarkers for AD occurrence. CCL17/TARC also holds great promise for being reliable biomarkers for AD severity as well as treatment response. Nitric oxide synthase 2 (NOS2)/inducible nitric oxide synthase (iNOS) which high expression is specific for psoriasis may be a good biomarker for differential diagnosis between psoriasis and AD in challenging clinical situations. AD children with food allergy (FA) have a unique endotype characterized by selectively altered expression of various molecules in the skin that can indicate FA coexistence. Unfortunately, although numerous potential biomarkers have been found, none of these candidates have been validated and implemented into routine clinical practice, which still separates us from the possibility of a precise approach to AD patients.

Characterization of Different Inflammatory Skin Conditions in a Mouse Model of DNCB-Induced Atopic Dermatitis

The mouse model of 2,4-dinitrochlorbenzene (DNCB)-induced human-like atopic dermatitis (hlAD) has been widely used to test novel treatment strategies and compounds. However, the study designs and methods are highly diverse, presenting different hlAD disease patterns that occur after sensitization and repeated challenge with DNCB on dorsal skin. In addition, there is a lack of information about the progression of the disease during the experiment and the achieved pheno- and endotypes, especially at the timepoint when therapeutic treatment is initiated. We here examine hlAD in a DNCB-induced BALB/cJRj model at different timepoints: (i) before starting treatment with dexamethasone, representing a standard drug control (day 12) and (ii) at the end of the experiment (day 22). Both timepoints display typical AD-associated characteristics: skin thickening, spongiosis, hyper- and parakeratosis, altered cytokine and gene expression, increased lipid mediator formation, barrier protein and antimicrobial peptide abnormalities, as well as lymphoid organ hypertrophy. Increased mast cell infiltration into the skin and elevated immunoglobulin E plasma concentrations indicate a type I allergy response. The DNCB-treated skin showed an extrinsic moderate sub-acute hlAD lesion at day 12 and an extrinsic mild sub-acute to chronic pheno- and endotype at day 22 with a dominating Th2 response. A dependency of the filaggrin formation and expression in correlation to the disease severity in the DNCB-treated skin was found. In conclusion, our study reveals a detailed classification of a hlAD at two timepoints with different inflammatory skin conditions and pheno- and endotypes, thereby providing a better understanding of the DNCB-induced hlAD model in BALB/cJRj mice.