Obesity is linked to disease severity in moderate to severe atopic dermatitis-Data from the prospective observational TREATgermany registry.

BACKGROUND: There are conflicting data on a potential association between obesity and atopic dermatitis (AD). The purpose of this study was to investigate the relationship between obesity and AD disease severity. METHODS: Patients from the TREATgermany registry cohort were divided into three groups according to their body mass index (BMI). Due to low numbers, underweight patients (BMI <18.5 kg/m2) were excluded from the analysis. Physician- and patient-reported disease severity scores as well as additional phenotypic characteristics were evaluated for association with BMI. Generalized linear mixed models and multinomial logit models, respectively, were applied to investigate the association of BMI, age, sex and current systemic AD treatment with disease severity. RESULTS: This study encompassed 1416 patients, of which 234 (16.5%) were obese (BMI ≥30 kg/m2). Obesity was associated with lower educational background and smoking. Otherwise, obese and non-obese AD patients had similar baseline characteristics. Increased BMI was associated with higher oSCORAD (adjusted ß: 1.24, 95% CI: 1.05-1.46, p = 0.013) and Patient-oriented eczema measure (POEM) (adjusted ß: 1.09, 95% CI: 1.01-1.17, p = 0.038). However, the absolute difference in the overall oSCORAD was small between obese and non-obese AD patients (Δ oSCORAD = 2.5). Allergic comorbidity was comparable between all three groups, with the exception of asthma which was more pronounced in obese patients (p < 0.001). DISCUSSION: In this large and well-characterized AD patient cohort, obesity is significantly associated with physician- and patient-assessed measures of AD disease severity. However, the corresponding effect sizes were low and of questionable clinical relevance. The overall prevalence of obesity among the German AD patients was lower than in studies on other AD cohorts from different countries, which confirms previous research on the German population and suggests regional differences in the interdependence of AD and obesity prevalence.

Detecting T-cell receptor clonality in patients with severe atopic dermatitis refractory to dupilumab.

BACKGROUND: Trials and real-life studies demonstrated clinically meaningful improvements of disease activity in the majority of patients with moderate to severe atopic dermatitis (AD) treated with the anti-IL-4RA-antibody dupilumab. However, misdiagnosis or confounding skin diseases in particular cutaneous T-cell lymphoma (CTCL) may lead to inadequate response. OBJECTIVE: To investigate the clinical and pathological features of patients with AD who showed insufficient response to dupilumab. METHODS: We reviewed the medical records of 371 patients treated with dupilumab for severe AD. Insufficient response was defined as failure to achieve an improvement of the eczema area severity index (EASI) of at least 50% (EASI-50) at Week 16 and of 75% (EASI-75) at Week 52. Among 46 patients with insufficient response, 35 patients consented to a re-evaluation including a full physical exam, biopsies and laboratory assessments including immunohistochemistry and T-cell receptor gene rearrangement analysis to differentiate CTCL. RESULTS: Of the 371 patients treated with dupilumab, 46 (12.3%) patients showed insufficient response to dupilumab. Of these, 35 underwent further evaluation, and 19 (54.2% of inadequate responders) were finally diagnosed with mycosis fungoides (MF). In these patients, transition to or addition of conventional MF treatment led to clinical improvements. CONCLUSION: Insufficient response to dupilumab treatment may help uncover early MF on an existing AD background.

Effects of psoriasis and psoralen exposure on the somatic mutation landscape of the skin.

Somatic mutations are hypothesized to play a role in many non-neoplastic diseases. We performed whole-exome sequencing of 1,182 microbiopsies dissected from lesional and nonlesional epidermis from 111 patients with psoriasis to search for evidence that somatic mutations in keratinocytes may influence the disease process. Lesional skin remained highly polyclonal, showing no evidence of large-scale spread of clones carrying potentially pathogenic mutations. The mutation rate of keratinocytes was similarly only modestly affected by the disease. We found evidence of positive selection in previously reported driver genes NOTCH1, NOTCH2, TP53, FAT1 and PPM1D and also identified mutations in four genes (GXYLT1, CHEK2, ZFP36L2 and EEF1A1) that we hypothesize are selected for in squamous epithelium irrespective of disease status. Finally, we describe a mutational signature of psoralens-a class of chemicals previously found in some sunscreens and which are used as part of PUVA (psoralens and ultraviolet-A) photochemotherapy treatment for psoriasis.

Safety and efficacy of amlitelimab, a fully human nondepleting, noncytotoxic anti-OX40 ligand monoclonal antibody, in atopic dermatitis: results of a phase IIa randomized placebo-controlled trial.

BACKGROUND: Atopic dermatitis (AD) is an inflammatory skin disease with significant unmet need. Blockade of the OX40-OX40 ligand (OX40L) costimulation pathway by targeting OX40L on antigen-presenting cells (APCs) with a fully human noncytotoxic, nondepleting anti-OX40L monoclonal antibody (amlitelimab; SAR445229; KY1005) is a novel way to modulate persistent inflammation. OBJECTIVES: To assess the safety and efficacy of amlitelimab over 16 weeks in adults with AD in a phase IIa double-blind placebo-controlled study. METHODS: The study was conducted at 19 hospitals in Germany, Poland, Spain and the UK. Eligible patients with moderate-to-severe AD were randomized (1 : 1 : 1) to low-dose intravenous (IV) amlitelimab (200 mg), high-dose IV amlitelimab (500 mg) or placebo, followed by three maintenance doses (50% of loading dose) at 4, 8 and 12 weeks, with safety follow-up to week 36. The co-primary endpoints were the incidence of treatment-emergent adverse events (all patients who received ≥ 1 dose of the study drug) and mean percentage change in Eczema Area and Severity Index (EASI) to week 16 (full analysis set). RESULTS: Between 13 December 2018 and 12 May 2020, 89 patients were randomly assigned to low- (n = 29) or high-dose amlitelimab (n = 30) or placebo (n = 29), of whom 88 proceeded to treatment [37 women (42%), 51 (58%) men; mean (SD) age 33.6 (11.9) years]. Amlitelimab was generally well tolerated with an unremarkable safety profile; no hypersensitivity events were reported. For the primary endpoint, the least square mean percentage change in EASI from baseline to week 16 was -80.12% [95% confidence interval (CI) -95.55 to -64.68; P = 0.009 vs. placebo] and -69.97% (95% CI -85.04 to -54.60; P = 0.07 vs. placebo) for the low- (n = 27) and high-dose (n = 27) amlitelimab groups, respectively, vs. -49.37% (95% CI -66.02 to -32.72) for placebo (n = 24). Numerically greater reductions in EASI were observed for amlitelimab vs. placebo from weeks 2 to 16. CONCLUSIONS: Novel targeting of OX40L-expressing APCs with amlitelimab was well tolerated and resulted in clinically meaningful improvements in AD.

Safety of upadacitinib in moderate-to-severe atopic dermatitis: An integrated analysis of phase 3 studies.

BACKGROUND: Upadacitinib is a selective reversible Janus kinase (JAK) inhibitor with established efficacy in moderate-to-severe atopic dermatitis (AD). OBJECTIVE: We evaluated the safety of upadacitinib in patients with moderate-to-severe AD. METHODS: Integrated safety data from the 16-week placebo-controlled periods of 1 phase 2b and 3 ongoing phase 3 studies (16 weeks) and longer-term safety data from patients receiving upadacitinib during the blinded extension periods of the three phase 3 studies were analyzed (all upadacitinib exposure). Treatment-emergent adverse events (TEAEs) were presented as exposure-adjusted rates per 100 patient-years (PY). RESULTS: Safety results were similar between the 16-week and all upadacitinib exposure groups. The latter group included 2485 patients (333 adolescents), receiving upadacitinib 15 mg (n = 1239) or 30 mg (n = 1246) for a mean duration of approximately 1 year. Upadacitinib was well tolerated by both adults and adolescents. TEAEs and discontinuation due to AEs were reported more frequently in patients receiving 30 mg upadacitinib (respectively, 311.9 and 5.7 events per 100 PY) versus 15 mg (respectively, 274.6 and 4.4 events per 100 PY). Serious adverse event rates (15/30 mg, 7.1/7.7 events per 100 PY) were similar in both groups. Acne was the most frequently reported adverse event (15/30 mg, 13.3/20.2 events per 100 PY). Serious infection rates were similar across treatment groups. Adjudicated major adverse cardiovascular event and venous thromboembolic event rates were ≤0.1 events per 100 PY. Rates of malignant neoplasms were within the expected range for the general population. CONCLUSIONS: Upadacitinib was well tolerated, and no new important safety risks were observed among adults and adolescents with moderate-to-severe AD treated for approximately 1 year compared to the known safety profile of upadacitinib.

miRNA expression profiles of the perilesional skin of atopic dermatitis and psoriasis patients are highly similar.

Atopic dermatitis (AD) and psoriasis vulgaris (PV) are chronic inflammatory skin diseases with heterogeneous molecular backgrounds. MicroRNAs (miRNAs) contribute to either development or regulation of many immune system related diseases. Only few miRNA profiling studies are available for AD and no comparisons between AD and PV skin miRNA profiles have been performed recently. We conducted a miRNA profiling analysis of skin, as well as serum, from adult AD and PV patients and control individuals. 130 miRNAs were differentially expressed in AD skin, of which 77 were common differentially expressed in AD and PV. No differentially expressed miRNAs were detected in serum. Pathway analyses revealed differentially expressed miRNAs to potentially target immune-system related pathways, including TNF-α, IL-2/STAT4 and IL-6/JAK/STAT3. Additional genetic analysis of published AD GWAS dataset detected association of several target genes of differentially expressed miRNAs in skin. Moreover, miR-28-5p, miR-31-5p, miR-378a-3p and miR-203a were validated as upregulated in the skin of AD and PV patients. All validated miRNAs were reliable predictive markers for AD or PV. In conclusion, miRNA expression pattern in the skin of adult AD patients is highly similar to that of PV with multiple differentially expressed miRNAs potentially involved in the regulation of immune responses in AD and PV.

ImmUniverse Consortium: Multi-omics integrative approach in personalized medicine for immune-mediated inflammatory diseases.

Immune mediated inflammatory diseases (IMIDs) are a heterogeneous group of debilitating, multifactorial and unrelated conditions featured by a dysregulated immune response leading to destructive chronic inflammation. The immune dysregulation can affect various organ systems: gut (e.g., inflammatory bowel disease), joints (e.g., rheumatoid arthritis), skin (e.g., psoriasis, atopic dermatitis), resulting in significant morbidity, reduced quality of life, increased risk for comorbidities, and premature death. As there are no reliable disease progression and therapy response biomarkers currently available, it is very hard to predict how the disease will develop and which treatments will be effective in a given patient. In addition, a considerable proportion of patients do not respond sufficiently to the treatment. ImmUniverse is a large collaborative consortium of 27 partners funded by the Innovative Medicine Initiative (IMI), which is sponsored by the European Union (Horizon 2020) and in-kind contributions of participating pharmaceutical companies within the European Federation of Pharmaceutical Industries and Associations (EFPIA). ImmUniverse aims to advance our understanding of the molecular mechanisms underlying two immune-mediated diseases, ulcerative colitis (UC) and atopic dermatitis (AD), by pursuing an integrative multi-omics approach. As a consequence of the heterogeneity among IMIDs patients, a comprehensive, evidence-based identification of novel biomarkers is necessary to enable appropriate patient stratification that would account for the inter-individual differences in disease severity, drug efficacy, side effects or prognosis. This would guide clinicians in the management of patients and represent a major step towards personalized medicine. ImmUniverse will combine the existing and novel advanced technologies, including multi-omics, to characterize both the tissue microenvironment and blood. This comprehensive, systems biology-oriented approach will allow for identification and validation of tissue and circulating biomarker signatures as well as mechanistic principles, which will provide information about disease severity and future disease progression. This truly makes the ImmUniverse Consortium an unparalleled approach.

Biomarkers of systemic treatment response in people with psoriasis: a scoping review.

BACKGROUND: Responses to the systemic treatments commonly used to treat psoriasis vary. Biomarkers that accurately predict effectiveness and safety would enable targeted treatment selection, improved patient outcomes and more cost-effective healthcare. OBJECTIVES: To perform a scoping review to identify and catalogue candidate biomarkers of systemic treatment response in psoriasis for the translational research community. METHODS: A systematic search of CENTRAL, Embase, LILACS and MEDLINE was performed for relevant articles published between 1990 and December 2021. Eligibility criteria were studies involving patients with psoriasis (any age, n ≥ 50) reporting biomarkers associated with systemic treatment response. The main outcomes were any measure of systemic treatment efficacy or safety. Data were extracted by one reviewer and checked by a second; studies meeting minimal quality criteria (use of methods to control for confounding) were formally assessed for bias. Candidate biomarkers were identified by an expert multistakeholder group using a majority voting consensus exercise and mapped to relevant cellular and molecular pathways. RESULTS: Of 71 included studies (67 studying effectiveness outcomes and eight safety outcomes; four studied both), most reported genomic or proteomic biomarkers associated with response to biologics (48 studies). Methodological or reporting limitations frequently compromised the interpretation of findings, including inadequate control for key covariates, lack of adjustment for multiple testing, and selective outcome reporting. We identified candidate biomarkers of efficacy to tumour necrosis factor inhibitors [variation in CARD14, CDKAL1, IL1B, IL12B and IL17RA loci, and lipopolysaccharide-induced phosphorylation of nuclear factor (NF)-κB in type 2 dendritic cells] and ustekinumab (HLA-C*06:02 and variation in an IL1B locus). None were supported by sufficient evidence for clinical use without further validation studies. Candidate biomarkers were found to be involved in the immune cellular crosstalk implicated in psoriasis pathogenesis, most notably antigen presentation, T helper (Th)17 cell differentiation, positive regulation of NF-κB, and Th17 cell activation. CONCLUSIONS: This comprehensive catalogue provides a key resource for researchers and reveals a diverse range of biomarker types and outcomes in the included studies. The candidate biomarkers identified require further evaluation in methodologically robust studies to establish potential clinical utility. Future studies should aim to address the common methodological limitations highlighted in this review to expedite discovery and validation of biomarkers for clinical use. What is already known about this topic? Responses to the systemic treatments commonly used to treat psoriasis vary. Biomarkers that accurately predict effectiveness and safety would enable targeted treatment selection, improved patient outcomes and more cost-effective healthcare. What does this study add? This review provides a comprehensive catalogue of investigated biomarkers of systemic treatment response in psoriasis. A diverse range of biomarker types and outcomes was found in the included studies, serving as a key resource for the translational research community.

Dupilumab Demonstrates Rapid Onset of Response Across Three Type 2 Inflammatory Diseases.

BACKGROUND: Type 2 inflammatory diseases often coexist in patients. Dupilumab targets type 2 inflammation and has demonstrated treatment benefits in patients with atopic dermatitis (AD), asthma, and chronic rhinosinusitis with nasal polyps (CRSwNP) with an acceptable safety profile. OBJECTIVE: This post hoc analysis across five phase 3 studies in patients with moderate to severe AD or asthma, or severe CRSwNP, evaluated time of onset and duration of the treatment response. METHODS: Patients received subcutaneous dupilumab 200/300 mg or placebo. Assessments included the Eczema Area and Severity Index, Peak Pruritus Numerical Rating Scale, and Dermatology Life Quality Index in AD; pre-bronchodilator FEV1, daily morning peak expiratory flow, and symptom scores in asthma; and University of Pennsylvania Smell Identification Test, daily nasal congestion, and loss of smell scores in CRSwNP. RESULTS: At week 2 after the initiation of dupilumab versus placebo, 67.8% versus 36.5% of AD patients achieved a clinically meaningful benefit (Eczema Area and Severity Index: 50% or greater improvement; Peak Pruritus Numerical Rating Scale: 3 point or greater improvement; or Dermatology Life Quality Index: 4 point or greater improvement) (P < .001). Moreover, 61.6% versus 39.9% of asthma patients achieved improvements in pre-bronchodilator FEV1 of 100 mL or greater and 48.8% versus 26.3% achieved 200 mL or greater improvement (both P < .001); 33.2% versus 5.6% of CRSwNP patients regained a sense of smell (P < .001). Treatment effects further improved or were sustained to the end of treatment. CONCLUSIONS: Clinically meaningful responses were achieved rapidly after the first dupilumab dose in AD, asthma, or CRSwNP and were sustained throughout treatment (see Video in this article's Online Repository at www.jaci-inpractice.org).

Direct cellular reprogramming enables development of viral T antigen-driven Merkel cell carcinoma in mice.

Merkel cell carcinoma (MCC) is an aggressive neuroendocrine skin cancer that frequently carries an integrated Merkel cell polyomavirus (MCPyV) genome and expresses viral transforming antigens (TAgs). MCC tumor cells also express signature genes detected in skin-resident, postmitotic Merkel cells, including atonal bHLH transcription factor 1 (ATOH1), which is required for Merkel cell development from epidermal progenitors. We now report the use of in vivo cellular reprogramming, using ATOH1, to drive MCC development from murine epidermis. We generated mice that conditionally expressed MCPyV TAgs and ATOH1 in epidermal cells, yielding microscopic collections of proliferating MCC-like cells arising from hair follicles. Immunostaining of these nascent tumors revealed p53 accumulation and apoptosis, and targeted deletion of transformation related protein 53 (Trp53) led to development of gross skin tumors with classic MCC histology and marker expression. Global transcriptome analysis confirmed the close similarity of mouse and human MCCs, and hierarchical clustering showed conserved upregulation of signature genes. Our data establish that expression of MCPyV TAgs in ATOH1-reprogrammed epidermal cells and their neuroendocrine progeny initiates hair follicle-derived MCC tumorigenesis in adult mice. Moreover, progression to full-blown MCC in this model requires loss of p53, mimicking the functional inhibition of p53 reported in human MCPyV-positive MCCs.

Cytokine responses in nonlesional psoriatic skin as clinical predictor to anti-TNF agents.

BACKGROUND: A major issue with the current management of psoriasis is our inability to predict treatment response. OBJECTIVE: Our aim was to evaluate the ability to use baseline molecular expression profiling to assess treatment outcome for patients with psoriasis. METHODS: We conducted a longitudinal study of 46 patients with chronic plaque psoriasis treated with anti-TNF agent etanercept, and molecular profiles were assessed in more than 200 RNA-seq samples. RESULTS: We demonstrated correlation between clinical response and molecular changes during the course of the treatment, particularly for genes responding to IL-17A/TNF in keratinocytes. Intriguingly, baseline gene expressions in nonlesional, but not lesional, skin were the best marker of treatment response at week 12. We identified USP18, a known regulator of IFN responses, as positively correlated with Psoriasis Area and Severity Index (PASI) improvement (P = 9.8 × 10-4) and demonstrate its role in regulating IFN/TNF responses in keratinocytes. Consistently, cytokine gene signatures enriched in baseline nonlesional skin expression profiles had strong correlations with PASI improvement. Using this information, we developed a statistical model for predicting PASI75 (ie, 75% of PASI improvement) at week 12, achieving area under the receiver-operating characteristic curve value of 0.75 and up to 80% accurate PASI75 prediction among the top predicted responders. CONCLUSIONS: Our results illustrate feasibility of assessing drug response in psoriasis using nonlesional skin and implicate involvement of IFN regulators in anti-TNF responses.

IRAK2 Has a Critical Role in Promoting Feed-Forward Amplification of Epidermal Inflammatory Responses.

Many inflammatory skin diseases are characterized by altered epidermal differentiation. Whether this altered differentiation promotes inflammatory responses has been unknown. Here, we show that IRAK2, a member of the signaling complex downstream of IL-1 and IL-36, correlates positively with disease severity in both atopic dermatitis and psoriasis. Inhibition of epidermal IRAK2 normalizes differentiation and inflammation in two mouse models of psoriasis- and atopic dermatitis-like inflammation. Specifically, we demonstrate that IRAK2 ties together proinflammatory and differentiation-dependent responses and show that this function of IRAK2 is specific to keratinocytes and acts through the differentiation-associated transcription factor ZNF750. Taken together, our findings suggest that IRAK2 has a critical role in promoting feed-forward amplification of inflammatory responses in skin through modulation of differentiation pathways and inflammatory responses.

Atopic dermatitis displays stable and dynamic skin transcriptome signatures.

BACKGROUND: Skin transcriptome studies in atopic dermatitis (AD) showed broad dysregulation as well as "improvement" under therapy. These observations were mainly made in trials and based on microarray data. OBJECTIVES: Our aim was to explore the skin transcriptome and the impact of systemic treatment in patients of the TREATgermany registry. METHODS: Biopsy specimens from 59 patients with moderate-to-severe AD before and 30 patients 12 weeks after start of systemic treatment (dupilumab [n = 22] or cyclosporine [n = 8]) and from 31 healthy controls were subjected to mRNA sequencing. Differential expression, pathway enrichment, correlation, and coexpression network analysis were conducted. RESULTS: Both lesional and nonlesional skin showed a stable "core" signature characterized by disturbed epidermal differentiation and activation of IL-31/IL-1 signaling. A second dynamic signature showed progressive enrichment for type 2 inflammation, TH17 signaling, and natural killer cell function. Markers correlated with disease activity have functions in epidermal barrier properties and immune modulation. IL4RA was among the top 3 central dysregulated genes. Cyclosporine led to a more pronounced global transcriptome reversion and normalized TH17 cell/IL23 signaling, whereas dupilumab led to a stronger increase in level of epidermal differentiation markers. Both treatments strongly decreased levels of type 2 markers, but overall the residual profile was still profoundly different from that of healthy skin. Lower levels of IL4RA and IL13 and high IL36A expression were related to a stronger clinical response to dupilumab. CONCLUSION: The AD core signature is characterized by dysregulation of genes related to keratinocyte differentiation and itch signaling. A dynamic signature reflects progressive immune responses dominated by type 2 cytokines with an additional role of TH17 and natural killer cell signaling.

Epigenetic regulation of the PGE2 pathway modulates macrophage phenotype in normal and pathologic wound repair.

Macrophages are a primary immune cell involved in inflammation, and their cell plasticity allows for transition from an inflammatory to a reparative phenotype and is critical for normal tissue repair following injury. Evidence suggests that epigenetic alterations play a critical role in establishing macrophage phenotype and function during normal and pathologic wound repair. Here, we find in human and murine wound macrophages that cyclooxygenase 2/prostaglandin E2 (COX-2/PGE2) is elevated in diabetes and regulates downstream macrophage-mediated inflammation and host defense. Using single-cell RNA sequencing of human wound tissue, we identify increased NF-κB-mediated inflammation in diabetic wounds and show increased COX-2/PGE2 in diabetic macrophages. Further, we identify that COX-2/PGE2 production in wound macrophages requires epigenetic regulation of 2 key enzymes in the cytosolic phospholipase A2/COX-2/PGE2 (cPLA2/COX-2/PGE2) pathway. We demonstrate that TGF-ß-induced miRNA29b increases COX-2/PGE2 production via inhibition of DNA methyltransferase 3b-mediated hypermethylation of the Cox-2 promoter. Further, we find mixed-lineage leukemia 1 (MLL1) upregulates cPLA2 expression and drives COX-2/PGE2. Inhibition of the COX-2/PGE2 pathway genetically (Cox2fl/fl Lyz2Cre+) or with a macrophage-specific nanotherapy targeting COX-2 in tissue macrophages reverses the inflammatory macrophage phenotype and improves diabetic tissue repair. Our results indicate the epigenetically regulated PGE2 pathway controls wound macrophage function, and cell-targeted manipulation of this pathway is feasible to improve diabetic wound repair.

Effectiveness of secondary prevention in metalworkers with work-related skin diseases and comparison with participants of a tertiary prevention program: A prospective cohort study.

BACKGROUND: In Germany, a multistep approach has been established to prevent work-related skin diseases (WRSDs). OBJECTIVES: To evaluate the effect of a secondary individual prevention program (SIP) in metalworkers with WRSD and to compare their characteristics with those of participants of a tertiary individual prevention program (TIP). PATIENTS AND METHODS: In a prospective cohort study, metalworkers with WRSD of the hands participating either in the SIP (n = 114) or in the TIP (n = 83) were recruited. At baseline and at the respective follow-up 8-12 weeks after the SIP or at dismissal from the TIP (3-4 weeks later), questionnaires were completed and the severity of WRSD was assessed. Saliva samples were collected for assessment of filaggrin (FLG) mutations and an explorative genome-wide association study (GWAS). RESULTS: Ninety-three SIP patients (81.6%) attended the follow-up. Disease severity was significantly reduced, and knowledge and protective behavior were significantly improved compared to baseline. Significant differences between SIP and TIP patients were found regarding duration and severity of symptoms, work absenteeism, tobacco smoking, and presence of atopic dermatitis, but not regarding FLG mutations and by GWAS. CONCLUSIONS: The SIP was effective in metalworkers with WRSDs. Individual factors may influence the course of the disease and the need for the TIP.

Health education decreases incidence of hand eczema in metal work apprentices: Results of a controlled intervention study.

BACKGROUND: Metal work apprentices (MWAs) frequently develop work-related hand eczema (HE). OBJECTIVES: To evaluate the effect of health education on incidence of work-related HE in MWAs and to assess confounding factors. MATERIALS/METHODS: In a prospective controlled intervention study, 131 MWAs received educational training on prevention of HE, whereas 172 MWAs and 118 office work apprentices served as controls. At baseline and during three yearly follow-ups, questionnaires were completed and hands were examined. Saliva samples were collected for assessment of filaggrin (FLG) null mutations and an explorative genome-wide association study (GWAS), and levels of various cytokines were assessed from stratum corneum samples. RESULTS: The 2-year and 3-year incidence of HE in the metalwork control group was 20.9% and 32.6%, respectively, which was significantly higher than in the intervention group (odds ratio [OR] 2.63, 95% confidence interval [CI] 1.31 to 5.28, P < .01 and OR 3.47, 95% CI 1.88 to 6.40, P < .0001). The knowledge score was higher in unaffected MWAs (P < .05). Other factors significantly associated with developing HE in MWAs were smoking cigarettes (P < .01) and FLG mutations (P < .001). No significant associations were found regarding epidermal cytokine levels and GWAS. CONCLUSIONS: Health education is effective in primary prevention of HE in MWAs. Individual factors should be considered in targeted counseling.

Evaluation and improvement of protein extraction methods for analysis of skin proteome by noninvasive tape stripping.

Analysis of the human skin proteome is key to understand molecular mechanisms maintaining health or leading to diseases of this important organ. For minimal invasive sampling of skin proteomes, the use of self-adhesive tape strips has been successfully applied. However, the methods previously presented were evaluated on different types of skin samples (e.g. healthy, diseased) and used a variety of cell lysis/protein extraction methods, which renders a systematic comparison and thus the identification of the most efficient protocols difficult. Here, we present a study comparing five different approaches for cell lysis and protein extraction from single tape strip biopsies. Extraction using a detergent mix or 1% SDS proved to be most efficient. Further, we replaced protein precipitation by single-pot, solid-phase-enhanced sample preparation (SP3), which strongly enhanced the number of identified proteins. This fully LC-MS compatible methodology provides a fast and reproducible approach for minimal invasive sampling of human skin proteomes. BIOLOGICAL SIGNIFICANCE: Fast and reproducible minimal invasive sampling of human skin proteomes is a major prerequisite for clinical proteomics studies aiming to decipher molecular mechanisms involved in the homeostasis as well as in the development of diseases. By optimization of tape strip sampling, e.g. the introduction of SP3 sample cleanup prior to LC-MS analysis, the presented protocol leads to yet not reported numbers of protein identifications from healthy human skin. Further, due to its efficiency it allows analysis from minimal sample amounts, e.g. from single tape strips, while established protocols relied on pooling of multiple tape strips. This provides the opportunity to perform spatially (lateral) resolved proteome analyses from different depths of the skin by analysis of consecutive strips.

Claudin-1 decrease impacts epidermal barrier function in atopic dermatitis lesions dose-dependently.

The transmembrane protein claudin-1 is a major component of epidermal tight junctions (TJs), which create a dynamic paracellular barrier in the epidermis. Claudin-1 downregulation has been linked to atopic dermatitis (AD) pathogenesis but variable levels of claudin-1 have also been observed in healthy skin. To elucidate the impact of different levels of claudin-1 in healthy and diseased skin we determined claudin-1 levels in AD patients and controls and correlated them to TJ and skin barrier function. We observed a strikingly broad range of claudin-1 levels with stable TJ and overall skin barrier function in healthy and non-lesional skin. However, a significant decrease in TJ barrier function was detected in lesional AD skin where claudin-1 levels were further reduced. Investigations on reconstructed human epidermis expressing different levels of claudin-1 revealed that claudin-1 levels correlated with inside-out and outside-in barrier function, with a higher coherence for smaller molecular tracers. Claudin-1 decrease induced keratinocyte-autonomous IL-1ß expression and fostered inflammatory epidermal responses to non-pathogenic Staphylococci. In conclusion, claudin-1 decrease beyond a threshold level results in TJ and epidermal barrier function impairment and induces inflammation in human epidermis. Increasing claudin-1 levels might improve barrier function and decrease inflammation and therefore be a target for AD treatment.

SERPINB2 and miR-146a/b are coordinately regulated and act in the suppression of psoriasis-associated inflammatory responses in keratinocytes.

Psoriasis is a chronic inflammatory skin disease with numerous involved factors. miR-146a and miR-146b (miR-146a/b) are anti-inflammatory miRNAs that are increased in psoriatic skin. SERPINB2 has been shown to be upregulated in the inflammation and infections. Here we aimed to study the relationship between miR-146a/b and SERPINB2 and to delineate the role of SERPINB2 in association of plaque psoriasis. We report increased SERPINB2 expression in the skin of psoriasis patients, which was in a positive relationship with psoriasis severity and in a negative relationship with miR-146a/b in psoriatic lesions. In cultured keratinocytes, both cellular and secreted SERPINB2 levels were strongly induced in response to IFN-γ and TNF-α. Interestingly, SERPINB2 mRNA was downregulated by IL-17A and the combination of TNF-α and IL-17A at time points when miR-146a was increased. The predicted binding site for miR-146a/b in 3' untranslated region of SERPINB2 revealed no activity in luciferase assay, while siRNA silencing of miR-146a/b direct targets IRAK1 and CARD10 resulted in reduced expression of SERPINB2, suggesting that miR-146a/b indirectly control SERPINB2 expression in the skin. The siRNA silencing of SERPINB2 increased the expression of IL-8, CXCL5 and CCL5 and migration of neutrophils revealing its anti-inflammatory role in keratinocytes. Our data together suggest that SERPINB2 and miR-146a/b are part of disease-related network of molecules that are coordinately regulated and act in controlling the inflammatory responses in psoriatic skin.

Transient epidermal barrier deficiency and lowered allergic threshold in filaggrin-hornerin (FlgHrnr-/- ) double-deficient mice.

BACKGROUND: Filaggrin (Flg) and hornerin (Hrnr) share similar structural and functional features. Both proteins have been implicated as essential proteins for skin barrier maintenance. Loss-of-function mutations of these genes constitute a risk factor for atopic dermatitis and eczema-related asthma. Furthermore, both FLG and HRNR protein levels are downregulated in patients with atopic dermatitis. Thus, mice deficient for Flg and Hrnr provide a novel model to study skin barrier impairment and the susceptibility for cutaneous inflammation. METHODS: By using appropriate targeting vectors and breeding strategies, we established a homozygous FlgHrnr double-deficient (FlgHrnr-/- ) mouse model lacking both genes including the intergenomic sequence. RESULTS: Neonates appeared normal, but developed a transient scaly phenotype with overall flaky appearance, but no overt skin phenotype in adulthood, thereby reflecting a subclinical barrier defect seen in humans. Structurally, FlgHrnr-/- mice displayed a markedly reduced granular layer and a condensed cornified layer. Functionally, FlgHrnr-/- mice showed permeability abnormalities and metabolic aberrations regarding the production of natural moisturizing factors (NMFs) in the stratum corneum. Surprisingly, although the immune system revealed no aberrations under steady-state conditions, FlgHrnr-/- mice are predisposed to mount an allergic contact dermatitis, especially at hapten threshold levels eliciting allergic reactions. CONCLUSIONS: Together, our FlgHrnr-/- mouse model nicely reflects the epicutaneous sensitization susceptibilities and inflammatory reactions to environmental insults in humans with impaired skin barrier functions.