Transcriptomic evaluation of skin tape-strips in children with allergic asthma uncovers epidermal barrier dysfunction and asthma-associated biomarkers abnormalities.

INTRODUCTION: Tape-strips, a minimally invasive method validated for the evaluation of several skin diseases, may help identify asthma-specific biomarkers in the skin of children with allergic asthma. METHODS: Skin tape-strips were obtained and analyzed with RNA-Seq from children with moderate allergic asthma (MAA) (n = 11, mean age 7.00; SD = 1.67), severe allergic asthma (SAA) (n = 9, mean age 9.11; SD = 2.37), and healthy controls (HCs) (n = 12, mean age 7.36; SD = 2.03). Differentially expressed genes (DEGs) were identified by fold change ≥2 with a false discovery rate <0.05. Transcriptomic biomarkers were analyzed for their accuracy in distinguishing asthma from HCs, their relationships with asthma-related outcomes (exacerbation rate, lung function-FEV1, IOS-R5-20, and lung inflammation-FeNO), and their links to skin (barrier and immune response) and lung (remodeling, metabolism, aging) pathogenetic pathways. RESULTS: RNA-Seq captured 1113 in MAA and 2117 DEGs in SAA. Epidermal transcriptomic biomarkers for terminal differentiation (FLG/filaggrin), cell adhesion (CDH19, JAM2), lipid biosynthesis/metabolism (ACOT2, LOXL2) were significantly downregulated. Gene set variation analysis revealed enrichment of Th1/IFNγ pathways (p < .01). MAA and SAA shared downregulation of G-protein-coupled receptor (OR4A16, TAS1R3), upregulation of TGF-ß/ErbB signaling-related (ACVR1B, EGFR, ID1/2), and upregulation of mitochondrial-related (HIGD2A, VDAC3, NDUFB9) genes. Skin transcriptomic biomarkers correlated with the annualized exacerbation rate and with lung function parameters. A two-gene classifier (TSSC4-FAM212B) was able to differentiate asthma from HCs with 100% accuracy. CONCLUSION: Tape-strips detected epithelial barrier and asthma-associated signatures in normal-appearing skin from children with allergic asthma and may serve as an alternative to invasive approaches for evaluating asthma endotypes.

Sclerotic-Type Cutaneous Chronic Graft-Versus-Host Disease Exhibits Activation of T Helper 1 and OX40 Cytokines.

Sclerotic-type cutaneous chronic graft-versus-host disease is a severe complication of allogeneic hematopoietic stem cell transplantation, with profound morbidity. A dearth of effective, targeted treatment options necessitates further investigation into the molecular mechanisms underlying this T-cell-mediated disease. In this study, we compared the transcriptome in skin biopsies from pediatric and young adult (aged <25 years) patients with sclerotic-type cutaneous chronic graft-versus-host disease (n = 7) with that in demographically matched healthy controls (n = 8) and patients with atopic dermatitis (n = 10) using RNA sequencing with RT-PCR and immunohistochemistry validation. Differential expression was defined as fold change > 1.5 and false discovery rate < 0.05. Sclerotic-type cutaneous chronic graft-versus-host disease exhibited strong and significant T helper (Th)1 skewing through key related cytokines and chemokines (CXCL9/10/11, IFNG/IFN-γ, STAT1/signal transducer and activator of transcription 1). Several markers related to the TSLP-OX40 axis were significantly upregulated relative to those in both controls and lesional atopic dermatitis, including TNFSF4/OX40L, TSLP, and IL33, as well as fibroinflammatory signatures characterized in a prior study in systemic sclerosis. Gene set variation analysis reflected marker-level findings, showing the greatest enrichment of the Th1 and fibroinflammatory pathways, with no global activation identified in Th2 or Th17/Th22. Cell-type deconvolution revealed a significant representation of macrophages and vascular endothelial cells. Sclerotic-type cutaneous chronic graft-versus-host disease in young patients may therefore be characterized by strong Th1-related upregulation with a unique TSLP-OX40 signature, suggesting new therapeutic avenues for this devastating disease.

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.

Implementation of regulatory guidance for JAK inhibitors use in patients with immune-mediated inflammatory diseases: An international appropriateness study.

BACKGROUND AND AIMS: The Pharmacovigilance Risk Assessment Committee (PRAC) proposed measures to address severe side effects linked to Janus kinase inhibitors (JAKi) in immune-mediated inflammatory diseases (IMID). Use of these medications in individuals aged 65 and older, those at high cardiovascular risk, active or former long-term smokers, and those with increased cancer risk should be considered only if no alternatives exist. Caution is advised when administering JAKi to patients at risk of venous thromboembolism. We aim to implement recommendations from regulatory guidelines based on areas of uncertainty identified. METHODS: A two-round modified Research and Development/University of California Los Angeles appropriateness methodology study was conducted. A panel of 21 gastroenterologists, dermatologists and rheumatologists used a 9-point Likert scale to rate the appropriateness of administering a JAKi for each proposed clinical scenario. Scores for appropriateness were categorized as appropriate, uncertain, or inappropriate. Two rounds were performed, each with online surveys and a virtual meeting to enable discussion and rating of each best practice. RESULTS: Round 1 involved participants rating JAKi appropriateness and suggesting descriptors to reduce uncertainty. Survey results were discussed in a virtual meeting, identifying areas of disagreement. In round 2, participants rated their agreement with descriptors from round 1, and the level of uncertainty and disagreement reduced. Age flexibility is recommended in the absence of other risk factors. Active counseling on modifiable risks (e.g., overweight, mild hyperlipidemia and hypertension) and smoking cessation is advised. Uncertainty persists regarding cancer risk due to various factors. CONCLUSIONS: We outlined regulatory guidance without a personalized evaluation of the patient's risk profile might lead to uncertainty and become an arid technicality. Therefore, we identified gaps and implemented PRAC recommendations to help health professionals in clinical practice.

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.

Oral difelikefalin reduces moderate to severe pruritus and expression of pruritic and inflammatory biomarkers in subjects with atopic dermatitis.

BACKGROUND: Pruritus is the most common and burdensome symptom of atopic dermatitis (AD). Pruritus-targeted treatments in AD are lacking, particularly for patients with milder skin disease. OBJECTIVE: We sought to evaluate the impact of the selective κ-opioid receptor agonist difelikefalin (DFK) on pruritus intensity and pruritus- and immune-related biomarkers in subjects with moderate to severe AD-related pruritus. METHODS: A phase 2 clinical trial investigated the efficacy and safety of oral DFK 0.25, 0.5, and 1.0 mg in subjects with moderate to severe AD-related pruritus. A biomarker substudy evaluated the effects of DFK on the expression of pruritus, TH2-associated genes, and skin barrier-related genes. RESULTS: In the clinical trial (N = 401), all DFK doses reduced itch versus placebo; however, the results were not statistically significant at week 12. In a subgroup of subjects in the trial with mild to moderate skin inflammation and moderate to severe itch (itch-dominant AD phenotype), DFK reduced itch at week 12 versus placebo. In the biomarker substudy, DFK downregulated the expression of key pruritus-related genes (eg, IL-31 and TRPV1) and the AD phenotype (eg, CCL17). Gene set variation analysis confirmed that DFK, but not placebo, downregulated pruritus-related genes and TH2 pathways. DFK improved skin barrier integrity markers and upregulated the expression of claudins and lipid metabolism-associated genes (eg, SEC14L6, ELOVL3, CYP1A2, and AKR1D1). CONCLUSIONS: DFK treatment reduced itch in subjects with moderate to severe AD-related pruritus, particularly those with an "itch-dominant" AD phenotype, and had an impact on the expression of pruritus, TH2-associated genes, and skin barrier-related genes. DFK is a promising therapy for AD-related pruritus; further clinical studies are warranted.

Crisaborole reverses dysregulation of the mild to moderate atopic dermatitis proteome toward nonlesional and normal skin.

BACKGROUND: Safe and effective long-term topical treatments for atopic dermatitis (AD) remain limited. OBJECTIVE: In this phase 2a, single-center, intrapatient, and vehicle-controlled study, we examine the mechanism of action of crisaborole 2% ointment, a topical nonsteroidal PDE4 (phosphodiesterase-4) inhibitor, in a proteomic analysis of 40 adults with mild to moderate AD and 20 healthy subjects. METHODS: Within the AD cohort, 2 target lesions were randomized in an intrapatient (1:1) manner to double-blind crisaborole/vehicle applied twice daily for 14 days. Punch biopsy specimens were collected for biomarker analysis at baseline from all participants, then from AD patients only at day 8 (optional) and day 15. RESULTS: Compared to the vehicle, crisaborole significantly reversed dysregulation of the overall lesional proteome and of key markers and pathways (eg, Th2, Th17/Th22, and T-cell activation) associated with AD pathogenesis toward both nonlesional and normal skin. Significant clinical correlations were observed with markers associated with nociception and Th2, Th17, and neutrophilic activation. LIMITATIONS: Study limitations include predominance of white patients in the cohort, relatively short treatment time, and regimented administration of crisaborole. CONCLUSION: Our results demonstrate crisaborole-induced normalization of the AD proteome toward a nonlesional molecular phenotype and further support topical PDE4 inhibition in the treatment of mild to moderate AD.

Age of onset defines two distinct profiles of atopic dermatitis in adults.

BACKGROUND: The incidence of adult-onset atopic dermatitis (AOAD) is increasing. However, the unique characteristics of AOAD compared to pediatric-onset AD persisting into adulthood (POAD) are underexplored, hampering the development of targeted-therapeutics for this growing population. We thus assessed the profile of AOAD in skin and blood compared to that of POAD. METHODS: We collected skin biopsies and blood from adults with AOAD, POAD, and healthy controls (n = 15 in each group). Skin samples were analyzed by RNA sequencing, qRT-PCR, and immunohistochemistry, and Olink Proseek multiplex assay was used to identify the serum proteomic profile. RESULTS: Compared to healthy controls, both AOAD and POAD showed cutaneous immune and barrier dysregulations with a shared Th2/Th22 hyperactivation. Overall, POAD showed greater inflammation in lesional skin, with more prominent expression of Th2/Th17/Th22 markers (CCL17/22, S100A8/9, IL-36A, PI3/Elafin, DEFB4) in POAD compared to AOAD (p-value < .05). In contrast, higher Th1-(IFN-γ, IL-2, IL-15, CCL5) upregulation and Th1-skewing were seen in AOAD. The epidermal barrier was also more compromised in POAD, with greater epidermal hyperplasia and lower expression of markers related to terminal differentiation, lipids, and cell adhesion. In parallel with increased rates of cardiovascular comorbidities, AOAD demonstrated many more significantly dysregulated proteins in serum (n = 148) compared to POAD (n = 86), including pro-inflammatory and cardiovascular-risk markers. Th1-related products showed significant correlations between their skin and blood expressions only in AOAD subjects. CONCLUSION: Age-of-onset delineates two distinct endophenotypes in adult AD potentially suggesting the need for broader (beyond Th2) therapeutic targeting in AOAD.

The translational revolution in atopic dermatitis: the paradigm shift from pathogenesis to treatment.

Atopic dermatitis (AD) is the most common inflammatory skin disease, and it is considered a complex and heterogeneous condition. Different phenotypes of AD, defined according to the patient age at onset, race, and ethnic background; disease duration; and other disease characteristics, have been recently described, underlying the need for a personalized treatment approach. Recent advancements in understanding AD pathogenesis resulted in a real translational revolution and led to the exponential expansion of the therapeutic pipeline. The study of biomarkers in clinical studies of emerging treatments is helping clarify the role of each cytokine and immune pathway in AD and will allow addressing the unique immune fingerprints of each AD subset. Personalized medicine will be the ultimate goal of this targeted translational research. In this review, we discuss the changes in the concepts of both the pathogenesis of and treatment approach to AD, highlight the scientific rationale behind each targeted treatment and report the most recent clinical efficacy data.

Proteomic characterization of atopic dermatitis blood from infancy to adulthood.

BACKGROUND: Patients with atopic dermatitis (AD) have systemic biomarker dysregulation that differs by age group; however, the proteomic characteristics of these age-based changes are unknown. OBJECTIVE: To profile blood proteins of patients with AD across different age groups versus age-appropriate controls. METHODS: Using the Olink high-throughput proteomic platform, we profiled 375 serum proteins of 20 infants (age, 0-5 years), 39 children (age, 6-11 years), 21 adolescents (age, 12-17 years), and 20 adults (age, ≥18 years) with moderate-to-severe AD and 83 age-appropriate controls. RESULTS: Each group presented a distinct systemic proteomic signature. Th2-related proteins were increased in infant AD and further intensified with age through adolescence and adulthood (interleukin 4/CCL13/CCL17). In contrast, Th1 axis down-regulation was detected in infants with AD and gradually reversed to increased Th1 products (interferon γ/CXCL9/CXCL10/CCL2) in patients with AD from childhood to adulthood. Despite their short disease duration, infants already had evidence of systemic inflammation, with significant upregulation of innate immunity (interleukin 17C/ interleukin-1RN), T-cell activation/migration (CCL19), Th2 (CCL13/CCL17), and Th17 (PI3) proteins. Adults with AD present unique upregulation of cardiovascular proteins related to coagulation and diabetes. LIMITATIONS: Cross-sectional observational study with a single time point. CONCLUSION: Systemic immune signatures of AD are age-specific beyond the shared Th2 immune activation. These data advocate for precision medicine approaches based on age-specific AD profiles.

The evolving landscape of biologic therapies for atopic dermatitis: Present and future perspective.

Atopic dermatitis (AD) is one of the most common, chronic inflammatory skin diseases with a significant physical, emotional and socioeconomic burden. In recent years the understanding of AD pathogenesis has expanded from the Th2-centred perspective, with the recognition of the involvement of other immune axes. In different AD endotypes, influenced by environment, genetics and race, transcriptomic profiles have identified differing contributions of multiple immune axes such as, Th17, Th22 and Th1. The enriched pathogenic model of AD has catalysed the development of numerous biologic therapies targeting a range of key molecules implicated in disease progression. Currently, dupilumab and tralokinumab, which both target the Th2 pathway, are the only approved biologic therapies for AD in the United States and Europe. New biologic therapies in development, however, target different Th2-pathway molecules along with cytokines in other immune axes, including Th17 and Th22, offering promise for varied treatments for this heterogeneous disease. As the biologic pipeline advances, the integration into clinical practice and approval of these experimental biologics may provide more effective, tailored therapeutic solutions and illuminate on the pathologic processes of AD across a broader, more diverse patient population.

Scalp biomarkers during dupilumab treatment support Th2 pathway pathogenicity in alopecia areata.

BACKGROUND: The mechanisms driving alopecia areata (AA) are still unclear, hindering development of targeted therapeutics. Specific Th2 targeting with dupilumab in AA provides a unique opportunity to dissect its pathogenesis and explore the role of Th2 pathway. METHODS: We evaluated changes in scalp biomarkers in AA patients (with and without concomitant atopy) randomized to weekly dupilumab or placebo for 24 weeks, followed by open-label dupilumab for 24 weeks. Changes in biomarker levels were measured at weeks 12, 24, and 48 and were also correlated with clinical hair regrowth. RESULTS: At week 24, preceding clinical hair regrowth outcomes, only dupilumab-treated patients presented significant suppression of cellular infiltrates, and multiple Th2-related, markers (CCL13/MCP-4, CCL18/PARC, CCL26/eotaxin-3, CCL24/Eotaxin-2), coupled with significant upregulation in the hair keratins. Th1-related suppression was evident later (week 48) when all patients received open-label dupilumab. Results were more pronounced in atopic AA patients, that showed 48% and 97% improvements in the lesional AA scalp profile at weeks 24 and 48, respectively, while 2% worsening was seen in the placebo arm at week 24. Moreover, placebo-treated patients presented 54% worsening in hair keratins when compared with baseline at week 24. At week 24, increases in hair keratins showed significant correlations only with decreases in Th2-related markers. CONCLUSIONS: Scalp biomarkers provide evidence of dupilumab efficacy in AA, detected even prior to clinical response, with exclusive correlations between early suppression of Th2 markers and increased hair keratins. These findings strengthen previous reports suggesting a possible role for Th2 cytokines as AA drivers.

Current emerging and investigational drugs for the treatment of chronic hand eczema.

INTRODUCTION: Chronic hand eczema (CHE) is a highly prevalent, burdensome condition associated with functional impairment. Currently, topical therapeutics are the mainstay of CHE management. However, many cases are refractory to existing topical therapeutics, and the few existing systemic options are often limited in efficacy and by their side effect profiles. AREAS COVERED: Following a brief overview of CHE pathogenesis and existing treatments, this review will outline the mechanisms and available data on emerging and investigational drugs currently being studied in clinical trials for the treatment of CHE. EXPERT OPINION: Immunomodulatory drugs such as topical and systemic JAK inhibitors and Th2-targeting antibodies such as dupilumab are currently under investigation for CHE treatment, with early promise. Management of CHE will likely move toward more targeted treatments through clinical trials and away from broad immunosuppressants such as cyclosporine and methotrexate, which have previously been investigated for CHE and have more side effects. In coming years, CHE patients may benefit from a wider range of both topical and systemic therapeutics that target immune pathways relevant to the various CHE subtypes.