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Hidradenitis suppurativa (HS) has a high unmet need for better treatments. Biopsies are considered the gold standard for studying molecular alterations in skin. A reproducible, minimally invasive approach is needed for longitudinal monitoring in trials and in pediatric populations. To determine whether skin tape strips can detect molecular alterations in HS and identify biomarkers of disease activity. We performed RNA sequencing on tape strips collected from lesional and healthy-appearing (nonlesional) HS skin (n = 22) and healthy controls (n = 21). We correlated the expression of skin biomarkers between tape strips and a previously published gene-signature of HS biopsies. Tape strips detected upregulation of known HS biomarkers (eg, Interleukin[IL]-17A) in nonlesional and/or lesional skin and also identified novel clinically actionable targets, including OX40 and JAK3. The expression of Th17 and tumor necrosis factor-α pathways were highly correlated between tape strips and biopsies. HS clinical severity was significantly associated with expression of biomarkers (eg tumor necrosis factor-α , IL-17 A/F, OX40, JAK1-3, IL-4R) in HS lesional and/or nonlesional skin. Sample size. Tape stripping is limited in depth. This study validates tape strips as a minimally-invasive approach to identify cutaneous biomarkers in HS. This provides a novel avenue for monitoring treatment efficacy and a potential step toward individualized therapy in HS. [ABSTRACT FROM AUTHOR]

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. To profile blood proteins of patients with AD across different age groups versus age-appropriate controls. 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. 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. Cross-sectional observational study with a single time point. 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. [ABSTRACT FROM AUTHOR]

The IL-36 pathway plays a key role in the pathogenesis of generalized pustular psoriasis (GPP). In a proof-of-concept clinical trial, treatment with spesolimab, an anti–IL-36 receptor antibody, resulted in rapid skin and pustular clearance in patients presenting with GPP flares. We sought to compare the molecular profiles of lesional and nonlesional skin from patients with GPP or palmoplantar pustulosis (PPP) with skin from healthy volunteers, and to investigate the molecular changes after spesolimab treatment in the skin and blood of patients with GPP flares. Pre- and post-treatment skin and blood samples were collected from patients with GPP who participated in a single-arm, phase I study (n = 7). Skin biopsies from patients with PPP (n = 8) and healthy volunteers (n = 16) were obtained for comparison at baseline. Biomarkers were assessed by RNA-sequencing, histopathology, and immunohistochemistry. In GPP and PPP lesions, 1287 transcripts were commonly upregulated or downregulated. Selected transcripts from the IL-36 signaling pathway were upregulated in untreated GPP and PPP lesions. In patients with GPP, IL-36 pathway–related signatures, T H 1/T H 17 and innate inflammation signaling, neutrophilic mediators, and keratinocyte-driven inflammation pathways were downregulated by spesolimab as early as week 1. Spesolimab also decreased related serum biomarkers and cell populations in the skin lesions from patients with GPP, including CD3+ T, CD11c+, and IL-36γ+ cells and lipocalin-2–expressing cells. In patients with GPP, spesolimab showed rapid modulation of commonly dysregulated molecular pathways in GPP and PPP, which may be associated with improved clinical outcomes. [Display omitted] [ABSTRACT FROM AUTHOR]

Background: Frontal fibrosing alopecia (FFA) is a progressive, scarring alopecia of the frontotemporal scalp that poses a substantial burden on quality of life. Large-scale global profiling of FFA is lacking, preventing the development of effective therapeutics.Objective: To characterize FFA compared to normal and alopecia areata using broad molecular profiling and to identify biomarkers linked to disease severity.Methods: This cross-sectional study assessed 33,118 genes in scalp using RNA sequencing and 350 proteins in serum using OLINK high-throughput proteomics. Disease biomarkers were also correlated with clinical severity and a fibrosis gene set.Results: Genes differentially expressed in lesional FFA included markers related to Th1 (IFNγ/CXCL9/CXCL10), T-cell activation (CD2/CD3/CCL19/ICOS), fibrosis (CXCR3/FGF14/FGF22/VIM/FN1), T-regulatory (FOXP3/TGFB1/TGFB3), and Janus kinase/JAK (JAK3/STAT1/STAT4) (Fold changes [FCH]>1.5, FDR<.05 for all). Only one protein, ADM, was differentially expressed in FFA serum compared to normal (FCH>1.3, FDR<.05). Significant correlations were found between scalp biomarkers (IL-36RN/IL-25) and FFA severity, as well as between JAK/STAT and fibrosis gene-sets (r>.6; P <.05).Limitations: This study was limited by a small sample size and predominantly female FFA patients.Conclusion: Our data characterize FFA as an inflammatory condition limited to scalp, involving Th1/JAK skewing, with associated fibrosis and elevated T-regulatory markers, suggesting the potential for disease reversibility with JAK/STAT inhibition. [ABSTRACT FROM AUTHOR]

Background: Although hidradenitis suppurativa (HS) shares some transcriptomic and cellular infiltrate features with psoriasis, their skin proteome remains unknown.Objective: To define and compare inflammatory protein biomarkers of HS and psoriasis skin.Methods: We assessed 92 inflammatory biomarkers in HS (n = 13), psoriasis (n = 11), and control skin (n = 11) using Olink high-throughput proteomics. We also correlated HS skin and blood biomarkers using proteomics and RNA sequencing.Results: We identified 57 differentially expressed proteins (DEPs) in lesional psoriasis and 64 DEPs in lesional HS skin, compared to healthy controls. Both HS and psoriasis lesional skin demonstrated a significant upregulation of T helper 1 and T helper 17 proteins. Healthy-appearing perilesional HS skin had 63 DEPs compared to healthy controls. Nonlesional HS and psoriasis skin had 24 and 7 DEPs, respectively, compared to healthy controls. Tumor necrosis factor and 8 other proteins were significantly correlated with clinical severity in perilesional HS skin (2 cm from a nodule).Limitations: Inclusion of only moderate-to-severe patients and the cohort size.Conclusion: HS has a greater inflammatory profile and is more diffusely distributed compared with psoriasis. Proteins correlated with disease severity are potential disease mediators. Perilesional skin is comparably inflamed to lesional skin, suggesting the need to treat beyond skin nodules. [ABSTRACT FROM AUTHOR]

Plaque psoriasis is a common, chronic, systemic, immune-mediated inflammatory disease. The Janus kinase-signal transducer and activator of transcription pathway plays a major role in intracellular cytokine signaling in inflammatory processes involved in psoriasis. Although Janus kinase (JAK) 1-3 inhibitors have demonstrated efficacy in patients with moderate-to-severe psoriasis, safety concerns persist and no JAK inhibitor has received regulatory approval to treat psoriasis. Thus, an opportunity exists for novel oral therapies that are safe and efficacious in psoriasis. Tyrosine kinase 2 (TYK2) is a member of the JAK family of kinases and regulates signaling and functional responses downstream of the interleukin 12, interleukin 23, and type I interferon receptors. Deucravacitinib, which is an oral, selective inhibitor that binds to the regulatory domain of TYK2, and brepocitinib (PF-06700841) and PF-06826647, which are topical and oral TYK2 inhibitors, respectively, that bind to the active (adenosine triphosphate-binding) site in the catalytic domain, are in development for psoriasis. Selective, allosteric inhibition of TYK2 signaling may reduce the potential for toxicities associated with pan-JAK inhibitors. This article reviews Janus kinase-signal transducer and activator of transcription and TYK2 signaling and the efficacy and safety of JAK inhibitors in psoriasis to date, focusing specifically on TYK2 inhibitors. [ABSTRACT FROM AUTHOR]

In previous human skin single-cell data, inflammatory cells constituted only a small fraction of the overall cell population, such that functional subsets were difficult to ascertain. Our aims were to overcome the aforesaid limitation by applying single-cell transcriptomics to emigrating cells from skin and elucidate ex vivo gene expression profiles of pathogenic versus regulatory immune cell subsets in the skin of individuals with psoriasis. We harvested emigrating cells from human psoriasis skin after incubation in culture medium without enzyme digestion or cell sorting and analyzed cells with single-cell RNA sequencing and flow cytometry simultaneously. Unsupervised clustering of harvested cells from psoriasis skin and control skin identified natural killer cells, T-cell subsets, dendritic cell subsets, melanocytes, and keratinocytes in different layers. Comparison between psoriasis cells and control cells within each cluster revealed that (1) cutaneous type 17 T cells display highly differing transcriptome profiles depending on IL-17A versus IL-17F expression and IFN-γ versus IL-10 expression; (2) semimature dendritic cells are regulatory dendritic cells with high IL-10 expression, but a subset of semimature dendritic cells expresses IL-23A and IL-36G in psoriasis; and (3) CCL27-CCR10 interaction is potentially impaired in psoriasis because of decreased CCL27 expression in basal keratinocytes. We propose that single-cell transcriptomics applied to emigrating cells from human skin provides an innovative study platform to compare gene expression profiles of heterogenous immune cells in various inflammatory skin diseases. [ABSTRACT FROM AUTHOR]

Although atopic dermatitis (AD) often presents in infancy and persists into adulthood, comparative characterization of AD skin among different pediatric age groups is lacking. We sought to define skin biopsy profiles of lesional and nonlesional AD across different age groups (0-5-year-old infants with disease duration <6 months, 6-11-year-old children, 12-17-year-old adolescents, ≥18-year-old adults) versus age-appropriate controls. We performed gene expression analyses by RNA-sequencing and real-time PCR (RT-PCR) and protein expression analysis using immunohistochemistry. T H 2/T H 22 skewing, including IL-13, CCL17/thymus and activation-regulated chemokine, IL-22, and S100As, characterized the common AD signature, with a global pathway-level enrichment across all ages. Nevertheless, specific cytokines varied widely. For example, IL-33, IL-1RL1/IL-33R, and IL-9, often associated with early atopic sensitization, showed greatest upregulations in infants. T H 17 inflammation presented a 2-peak curve, with highest increases in infants (including IL-17A and IL-17F), followed by adults. T H 1 polarization was uniquely detected in adults, even when compared with adolescents, with significant upregulation in adults of IFN-γ and CXCL9/CXCL10/CXCL11. Although all AD age groups had barrier abnormalities, only adults had significant decreases in filaggrin expression. Despite the short duration of the disease, infant AD presented robust downregulations of multiple barrier-related genes in both lesional and nonlesional skin. Clinical severity scores significantly correlated with T H 2/T H 22-related markers in all pediatric age groups. The shared signature of AD across ages is T H 2/T H 22-skewed, yet differential expression of specific T H 2/T H 22-related genes, other T H pathways, and barrier-related genes portray heterogenetic, age-specific molecular fingerprints. [ABSTRACT FROM AUTHOR]

Hidradenitis suppurativa (HS), also known as acne inversa, is a chronic, painful, and burdensome inflammatory disease manifesting in nodules and abscesses, with progression to chronically draining tunnels in later-stage disease. We sought to determine whether HS tunnels are immunologically active participants in disease activity. Skin biopsy specimens were obtained by using ultrasound guidance in untreated patients with HS and those enrolled in an open-label study of brodalumab (ClinicalTrials.gov identifier NCT03960268) for patients with moderate-to-severe HS. Immunohistochemistry of HS biopsy specimens demonstrated that the epithelialized HS tunnels recapitulate the psoriasiform epidermal hyperplasia morphology of the overlying epidermis, displaying molecular inflammation, including S100A7 (psoriasin) positivity, as well as features of epidermal skin, including loricrin, filaggrin, lipocalin-2, and Melan-A positive cells. Tunnels were associated with increased infiltration of T cells, dendritic cells, and neutrophils; formation of neutrophil extracellular traps, and increased expression of psoriasiform proinflammatory cytokines. Unsupervised hierarchical clustering demonstrated a separation of HS samples based on the presence or absence of tunnels. Tunnels isolated by microdissection had higher levels of epithelium-derived inflammatory cytokines compared with the overlying epidermis and healthy controls. Clinically, the size and draining of the tunnels were decreased with treatment with the IL-17RA antagonist brodalumab. These data suggest that tunnels are a source of inflammation in HS. [Display omitted] [ABSTRACT FROM AUTHOR]

Molecular studies in atopic dermatitis (AD) are largely restricted to patients with moderate-to-severe disease. Our aim was to evaluate skin and blood abnormalities in mild, moderate, and severe AD. Skin and blood samples were obtained from 61 patients with AD (20 with mild or limited disease, 17 with moderate disease, and 24 with severe disease) and 20 healthy subjects. Immune and barrier markers were measured in lesional, nonlesional, and healthy skin by quantitative real-time PCR and immunohistochemistry, and in blood by using the OLINK proteomic assay. Cellular markers of epidermal hyperplasia and T-cell/dendritic cell infiltration were increased in AD tissues of all patients in all severity groups versus in those of controls, whereas downstream T H 2 cell–, T H 22 cell–, T H 1 cell–, and T H 17 cell–related mediators demonstrated incremental elevations with increasing disease severity, in both lesional and nonlesional skin. Whereas the levels of the T H 2 (IL13, CCL17, and CCL26) and T H 22 (IL-22) cytokines were significantly elevated in both AD lesional and nonlesional skin of all patients regardless of the severity of their disease, patients with mild or limited AD showed increases in their levels of T H 1 cell (IFNG, CXCL9, and CXCL10) and T H 17 cell (IL-17A, CCL20, and CXCL1) markers in lesional but not nonlesional skin. Regulatory T-cell–related mediators (IL-10 and FOXP3) were comparably upregulated in all groups, without displaying the severity-based gradient in other immune axes. Unsupervised clustering aligned samples along a severity spectrum, where nonlesional mild or limited AD skin clustered with the samples from healthy controls. Furthermore, whereas the blood profiles of patients with moderate and severe AD showed gradual increases in the levels of T H 1 cell–, T H 2 cell–, and T H 17 cell–related and atherosclerosis and/or cardiovascular risk (CCL7, FGF21, and IGFBP1) proteins, the blood profiles of patients with mild or limited AD lacked significant differences from those of the controls. Mild and limited AD show high levels of T H 2/T H 22 cell activation that is primarily localized to skin lesions and lacks the systemic inflammation of moderate and severe disease. [Display omitted] [ABSTRACT FROM AUTHOR]

Background: Although there is increased understanding of the alopecia areata (AA) pathogenesis based on studies in scalp tissues, little is known about its systemic profile.Objective: To evaluate the blood proteomic signature of AA and determine biomarkers associated with increased disease severity.Methods: In a cross-sectional study, we assessed 350 inflammatory and cardiovascular proteins using OLINK high-throughput proteomics in patients with moderate to severe AA (n = 35), as compared with healthy individuals (n = 36), patients with moderate to severe psoriasis (n = 19), and those with atopic dermatitis (n = 49).Results: Seventy-four proteins were significantly differentially expressed between AA and control individuals (false discovery rate, <.05) including innate immunity (interleukin [IL] 6/IL-8), T helper (Th) type 1 (interferon [IFN] γ/CXCL9/CXCL10/CXCL11), Th2 (CCL13/CCL17/CCL7), Th17 (CCL20/PI3/S100A12), and cardiovascular-risk proteins (OLR1/OSM/MPO/PRTN3). Eighty-six biomarkers correlated with AA clinical severity (P < .05), including Th1/Th2, and cardiovascular/atherosclerosis-related proteins, including SELP/PGLYRP1/MPO/IL-18/OSM (P < .05). Patients with AA totalis/universalis showed the highest systemic inflammatory tone, including cardiovascular risk biomarkers, compared to control individuals and even to patients with atopic dermatitis and those with psoriasis. The AA profile showed some Th1/Th2 differences in the setting of concomitant atopy.Limitations: Our analysis was limited to 350 proteins.Conclusion: This study defined the abnormalities of moderate to severe AA and associated circulatory biomarkers. It shows that AA has systemic immune, cardiovascular, and atherosclerosis biomarker dysregulation, suggesting the need for systemic treatment approaches. [ABSTRACT FROM AUTHOR]

Our current understanding of atopic dermatitis (AD) and psoriasis pathophysiology is largely derived from skin biopsy studies that cause scarring and may be impractical in large-scale clinical trials. Although tape strips show promise as a minimally invasive technique in these common diseases, a comprehensive molecular profiling characterizing and differentiating the 2 diseases in tape strips is unavailable. Our aim was to construct a global transcriptome of tape strips from lesional and nonlesional skin of adults with moderate-to-severe AD and psoriasis. A total of 20 tape strips were obtained from lesional and nonlesional skin of patients with AD and psoriasis and skin from controls (n = 20 each); the strips were subjected to RNA sequencing (RNA-seq), with quantitative RT-PCR validation of immune and barrier biomarkers. We detected RNA-seq profiles in 96 of 100 of samples (96%), with 4123 and 5390 genes differentially expressed in AD and psoriasis lesions versus in controls, respectively (fold change ≥ 2; false discovery rate [FDR] < 0.05). Nonlesional tape-stripped skin from patients with AD was more similar to lesional skin than to nonlesional skin of patients with psoriasis, which showed larger differentiation from lesions. AD and psoriasis tissues shared increases in levels of dendritic cell and T-cell markers (CD3, ITGAX/CD11c, and CD83), but AD tissues showed preferential T H 2 skewing (IL-13, CCL17/TARC, and CCL18), whereas psoriasis was characterized by higher levels of expression of T H 17-related (IL-17A/F and IL-36A/IL-36G), T H 1-related (IFN-γ and CXCL9/CXCL10), and innate immunity–related (nitric oxide synthase 2/inducible nitric oxide synthase and IL-17C) products (FDR < 0.05). Terminal differentiation (FLG2 and LCE5A), tight junction (CLDN8), and lipid biosynthesis and metabolism (FA2H and ALOXE3) products were significantly downregulated in both AD and psoriasis (FDR < 0.05). Nitric oxide synthase 2/inducible nitric oxide synthase expression (determined by quantitative PCR) differentiated AD and psoriasis with 100% accuracy. RNA-seq tape strip profiling detected distinct immune and barrier signatures in lesional and nonlesional AD and psoriasis skin, suggesting their utility as a minimally invasive alternative to biopsies for detecting disease biomarkers. [ABSTRACT FROM AUTHOR]

Background: Hidradenitis suppurativa is an autoinflammatory disorder of keratinization, with dysregulation of T helper type 17 cytokines. Brodalumab is a monoclonal antibody that targets the interleukin (IL) 17 receptor A receptor.Objectives: To assess the safety and tolerability and clinical response at weeks 12 and 24 of brodalumab in moderate to severe HS. Ten participants with no history of inflammatory bowel disease were administered brodalumab 210 mg/1.5 mL subcutaneously at weeks 0, 1, and 2 and every 2 weeks thereafter until week 24. Participants were assessed for adverse events (grade 2/3 adverse events) and clinical response (Hidradenitis Suppurativa Clinical Response [HiSCR], Sartorius, International Hidradenitis Suppurativa Severity Scoring System [IHS4]), including ultrasonography and skin biopsies.Results: All 10 participants completed the study. No grade 2/3 adverse events associated with the use of brodalumab were reported. All patients (100%) achieved HiSCR, and 80% achieved IHS4 category change at week 12. HiSCR achievement occurred as early as week 2, likely due to the unique blockade of IL-17A, IL-17C, and IL-17F by brodalumab. Significant improvements were seen in pain, itch, quality of life, and depression.Conclusions: Brodalumab was well tolerated in this HS cohort, with no serious adverse events and improvement in clinical outcomes. Alterations in dose frequency may be required in those with advanced disease, which requires further exploration. [ABSTRACT FROM AUTHOR]

Atopic dermatitis (AD) is a prevalent inflammatory skin disease with a complex pathogenesis involving immune cell and epidermal abnormalities. Despite whole tissue biopsy studies that have advanced the mechanistic understanding of AD, single cell–based molecular alterations are largely unknown. Our aims were to construct a detailed, high-resolution atlas of cell populations and assess variability in cell composition and cell-specific gene expression in the skin of patients with AD versus in controls. We performed single-cell RNA sequencing on skin biopsy specimens from 5 patients with AD (4 lesional samples and 5 nonlesional samples) and 7 healthy control subjects, using 10× Genomics. We created transcriptomic profiles for 39,042 AD (lesional and nonlesional) and healthy skin cells. Fibroblasts demonstrated a novel COL6A5 + COL18A1 + subpopulation that was unique to lesional AD and expressed CCL2 and CCL19 cytokines. A corresponding LAMP3 + dendritic cell (DC) population that expressed the CCL19 receptor CCR7 was also unique to AD lesions, illustrating a potential role for fibroblast signaling to immune cells. The lesional AD samples were characterized by expansion of inflammatory DCs (CD1A + FCER1A +) and tissue-resident memory T cells (CD69 + CD103 +). The frequencies of type 2 (IL13 +)/type 22 (IL22 +) T cells were higher than those of type 1 (IFNG +) in lesional AD, whereas this ratio was slightly diminished in nonlesional AD and further diminished in controls. AD lesions were characterized by expanded type 2/type 22 T cells and inflammatory DCs, and by a unique inflammatory fibroblast that may interact with immune cells to regulate lymphoid cell organization and type 2 inflammation. [ABSTRACT FROM AUTHOR]

Background: The hidradenitis suppurativa clinical response (HiSCR) is the gold standard primary outcome measure for hidradenitis suppurativa clinical trials; however, it does not assess the presence of draining tunnels, a common finding in advanced disease. It is unclear what the effect of the presence or absence of draining tunnels has on the efficacy of adalimumab therapy in moderate and advanced disease.Objectives: We evaluated the efficacy of adalimumab versus placebo using the International Hidradenitis Suppurativa Severity Scoring System (IHS4). Additionally, we assessed the effect of draining tunnels on therapeutic response as measured by both the HiSCR and change in nodule counts.Methods: Reanalysis was conducted with the IHS4 and PIONEER 1 and 2 individual patient data. Both binary outcomes (achieving HiSCR and achieving change in IHS4 severity category) and continuous outcomes (nodule counts and IHS4 score) were calculated with R. Regression modeling was undertaken to assess the effect of draining tunnels and other variables. P < .05 was considered statistically significant.Results: The significance of adalimumab therapy depended on the outcome measure used. Placebo response rates were highest when binary outcome measures were used. Draining tunnels, smoking, antibiotics, and body mass index influenced HiSCR response in PIONEER 2. Significant differences in disease severity were observed between PIONEER 1 and 2 data sets.Conclusions: Elevated placebo response rates in PIONEER 1 and 2 are partially attributable to the use of binary outcome measures. Draining tunnels influence clinical response as measured by HiSCR and nodule counts in PIONEER 2. Further investigation into the effect of body mass index on clinical response is required. [ABSTRACT FROM AUTHOR]

Background: Moderate-to-severe atopic dermatitis (AD) is increasingly recognized as a systemic disease, largely due to proteomic blood studies. There are growing efforts to develop AD biomarkers using minimal tissues.Objective: To characterize the AD skin proteomic signature and its relationship with the blood proteome and genomic skin profile in the same individuals.Methods: We evaluated lesional and nonlesional biopsy samples and blood from 20 individuals with moderate-to-severe AD and 28 healthy individuals using Olink Proteomics (Uppsala, Sweden), using 10 μg/10 μL for skin and blood and RNA sequencing of the skin.Results: The AD skin proteome demonstrated significant upregulation in lesional and even in nonlesional skin compared with controls in inflammatory markers (matrix metalloproteinase 12; T-helper cell [Th]2/interleukin [IL]-1 receptor-like 1[IL1RL1]/IL-33R, IL-13, chemokine [C-C motif] ligand [CCL] 17; Th1/C-X-C motif chemokine 10; Th17/Th22/PI3, CCL20, S100A12), and in cardiovascular-associated proteins (E-selectin, matrix metalloproteinases, platelet growth factor, myeloperoxidase, fatty acid binding protein 4, and vascular endothelial growth factor A; false discovery rate, <0.05). Skin proteins demonstrated much higher and significant upregulations (vs controls) compared with blood, suggesting a skin source for the inflammatory/cardiovascular profile. Gene and protein expressions were correlated (r = 0.410, P < .001), with commonly upregulated inflammatory and cardiovascular risk-associated products, suggesting protein translation in skin.Limitations: Our analysis was limited to 354 proteins.Conclusions: The AD skin proteome shows an inflammatory and cardiovascular signature even in nonlesional skin, emphasizing the need for proactive treatment. Skin proteomics presents a sensitive option for biomarker monitoring. [ABSTRACT FROM AUTHOR]

IL-17 antagonists induce impressive clinical benefits in psoriasis, but it is unknown to what extent cellular and molecular psoriasis characteristics are suppressed by a clinically relevant dose/schedule of any IL-17-receptor antagonist. We sought to examine the effects of the IL-17 receptor-A antagonist brodalumab, on clinical and molecular psoriasis features over a 12-week period. A subset of patients (n = 116) enrolled in 3 phase-3 randomized clinical trials (AMAGINE -1 [Efficacy, Safety, and Withdrawal and Retreatment With Brodalumab in Moderate to Severe Plaque Psoriasis Subjects], -2 [P3 Study Brodalumab in Treatment of Moderate to Severe Plaque Psoriasis], and -3 [Efficacy and Safety of Brodalumab Compared With Placebo and Ustekinumab in Moderate to Severe Plaque Psoriasis in Subjects]) participated in a mechanistic substudy where punch biopsies were collected (lesional and nonlesional skin) between baseline and 12 weeks. This cohort included moderate-to-severe psoriasis patients treated with 140 mg (n = 46), 210 mg (n = 41) brodalumab, or placebo (n = 29). Key epidermal psoriatic features, including T-cell and dendritic cell subsets, were examined using immunohistochemistry. Treatment-induced changes in lesional skin gene expression profiles were evaluated using Affymetrix arrays. IL-17 receptor-A antagonism caused extensive improvements in clinical, histologic, and transcriptomic features of psoriasis. Cellular infiltrates (CD3+, CD8+, CD11c+, CD163+), markers of keratinocyte proliferation (Ki67+, KRT16), and inflammatory cytokines (IL-17A/C/F, IL-23A, IL-12B) decreased progressively, reaching close to nonlesional levels, paralleled by decreases in epidermal thickness. Psoriasis transcriptome gene expression improved ∼85% to 95% in responders whose psoriasis area severity index improved by 75% from baseline by week 12 (n = 63), compared with ∼30% to 65% in nonresponders (n = 12), while the residual disease genomic profile was 10% of the psoriasis transcriptome, which is less than for earlier generation drugs. IL-17–dependent gene expression, including keratinocyte genes, improved earlier and more extensively following brodalumab treatment compared with ustekinumab treatment (anti-IL-23/-IL-12). The clinically approved dose and schedule for brodalumab leads to nearly complete resolution of clinical, histologic, and transcriptomic features of psoriasis. Evidently, IL-17–induced release of keratinocyte-derived inflammatory mediators is a key driver of psoriasis pathogenesis. [ABSTRACT FROM AUTHOR]

The circulating immune phenotype was defined in adults and young children with early atopic dermatitis (AD), but chronologic changes in the blood of infants and children with AD through adolescence have not been explored. We sought to compare immune activation and cytokine polarization in the blood of 0- to 5-year-old (n = 39), 6- to 11-year-old (n = 26), 12- to 17-year-old (n = 21) and 18-year-old or older (n = 43) patients with AD versus age-matched control subjects. Flow cytometry was used to measure IFN-γ, IL-9, IL-13, IL-17, and IL-22 cytokine levels in CD4+/CD8+ T cells, with inducible costimulator molecule and HLA-DR defining midterm and long-term T-cell activation, respectively, within skin-homing/cutaneous lymphocyte antigen (CLA)+ versus systemic/CLA− T cells. Unsupervised clustering differentiated patients based on their blood biomarker frequencies. Although CLA+ T H 1 frequencies were significantly lower in infants with AD versus all older patients (P <.01), frequencies of CLA+ T H 2 T cells were similarly expanded across all AD age groups compared with control subjects (P <.05). After infancy, CLA− T H 2 frequencies were increased in patients with AD in all age groups, suggesting systemic immune activation with disease chronicity. IL-22 frequencies serially increased from normal levels in infants to highly significant levels in adolescents and adults compared with levels in respective control subjects (P <.01). Unsupervised clustering aligned the AD profiles along an age-related spectrum from infancy to adulthood (eg, inducible costimulator molecule and IL-22). The adult AD phenotype is achieved only in adulthood. Unique cytokine signatures characterizing individual pediatric endotypes might require age-specific therapies. Future longitudinal studies, comparing the profile of patients with cleared versus persistent pediatric AD, might define age-specific changes that predict AD clearance. [ABSTRACT FROM AUTHOR]

Moderate-to-severe atopic dermatitis (AD) has been associated with significant disease burden and systemic abnormalities and often requires systemic treatments. Currently, safe and effective oral systemic treatments for moderate-to-severe AD are not yet available. ASN002 is an oral inhibitor of the Janus kinase/spleen tyrosine kinase signaling pathways, targeting several cytokine axes (T H 2/T H 22/T H 17/T H 1) and epidermal differentiation. We sought to evaluate the effect of ASN002 on the cellular and molecular biomarker profile of patients with moderate-to-severe AD and to correlate changes in biomarkers to improvements in clinical severity measures and pruritus. Thirty-six patients with moderate-to-severe AD were randomized to groups with dose escalation of ASN002 (20, 40, and 80 mg) and a placebo group. Skin biopsy specimens were performed at baseline, day 15, and day 29. Gene expression studies were conducted by using microarray and quantitative RT-PCR, and cellular infiltrates and protein expression were studied by using immunohistochemistry. ASN002 reversed the lesional skin transcriptome toward a nonlesional phenotype. It also rapidly and significantly suppressed key inflammatory pathways implicated in AD pathogenesis, including T H 2 (IL4 receptor [IL4R] , IL13 , CCL13 /monocyte chemoattractant protein 4, CCL17 /thymus and activation-regulated chemokine, CCL18 /pulmonary and activation-regulated chemokine, CCL22 /macrophage-derived chemokine, and CCL26 /eotaxin-3), T H 17/T H 22 (lipocalins, PI3 /elafin, CCL20 , S100A7 / S100A8 / S100A9 , and IL36G / IL36RN), and T H 1 (IFNG , CXCL9 / CXCL11 , and MX1) axes and barrier-related measures (filaggrin [FLG] and CLDN23). Significant improvements in AD gene signatures were observed predominantly in the 40- and 80-mg groups. Smaller and largely nonsignificant molecular changes were seen in the 20-mg and placebo groups. The Janus kinase/spleen tyrosine kinase inhibitor ASN002 significantly suppressed key AD inflammatory pathways, corresponding to clinical response. ASN002 might be an effective novel therapeutic agent for moderate-to-severe AD. [ABSTRACT FROM AUTHOR]

Psoriasis is a chronic inflammatory skin disease characterized by IL-17-mediated immune responses. p38 is known to be highly activated in the psoriatic epidermis; however, whether p38 is involved in the development of psoriasis is unclear. We sought to demonstrate that activation of p38 mitogen-activated protein kinase is sufficient to induce psoriatic inflammation in mice and that cutaneous p38 activities are the topical therapeutic targets for psoriasis. A p38 activator, anisomycin, was applied daily to murine skin. Transcriptomic analyses were performed to evaluate the similarities of the skin responses to those in human psoriasis and the existing animal model. BIRB796, a small-molecule inhibitor targeting p38 activities, was applied to the murine psoriatic models topically or to human psoriatic skin specimens ex vivo. Topical treatment with anisomycin induced key signatures in psoriasis, such as epidermal thickening, neutrophil infiltration, and gene expression of Il1a , Il1b , Il6 , Il24 , Cxcl1 , Il23a , and Il17a , in treated murine skin. These responses were fully abrogated by topical treatment with BIRB796, and were reduced in IL-17A–deficient mice. Transcriptomic analyses demonstrated the similarities of anisomycin-induced dermatitis to human psoriasis and imiquimod-induced murine psoriatic dermatitis. Furthermore, BIRB796 targeting of p38 activities reduced expression of psoriasis-related genes in both human keratinocytes stimulated with recombinant IL-17A in vitro and psoriatic skin specimens ex vivo. Therefore our findings suggest that cutaneous p38 activation can be a key event in patients with psoriasis and a potential topical therapeutic target of a small molecule. [ABSTRACT FROM AUTHOR]