Peripheral blood gene expression profile of infants with atopic dermatitis

To enhance the understanding of molecular mechanisms and mine previously unidentified biomarkers of pediatric atopic dermatitis, PBMC gene expression profiles were generated by RNA sequencing in infants with atopic dermatitis and age-matched controls. A total of 178 significantly differentially expressed genes (DEGs) (115 upregulations and 63 downregulations) were seen, compared with those in healthy controls. The DEGs identified included IL1β, TNF, TREM1, IL18R1, and IL18RAP. DEGs were validated by real-time RT- qPCR in a larger number of samples from PBMCs of infants with atopic dermatitis aged <12 months. Using the DAVID (Database for Annotation, Visualization and Integrated Discovery) database, functional and pathway enrichment analyses of DEGs were performed. Gene ontology enrichment analysis showed that DEGs were associated with immune responses, inflammatory responses, regulation of immune responses, and platelet activation. Pathway analysis indicated that DEGs were enriched in cytokine‒cytokine receptor interaction, immunoregulatory interactions between lymphoid and nonlymphoid cells, hematopoietic cell lineage, phosphoinositide 3-kinase‒protein kinase B signaling pathway, NK cell‒mediated cytotoxicity, and platelet activation. Furthermore, the protein‒protein interaction network was predicted using the STRING (Search Tool for the Retrieval of Interacting Genes/Proteins) database and visualized with Cytoscape software. Finally, on the basis of the protein‒protein interaction network, 18 hub genes were selected, and two significant modules were obtained. In conclusion, this study sheds light on the molecular mechanisms of pediatric atopic dermatitis and may provide diagnostic biomarkers and therapeutic targets

The microbiome in patients with atopic dermatitis.

As an interface with the environment, the skin is a complex ecosystem colonized by many microorganisms that coexist in an established balance. The cutaneous microbiome inhibits colonization with pathogens, such as Staphylococcus aureus, and is a crucial component for function of the epidermal barrier. Moreover, crosstalk between commensals and the immune system is now recognized because microorganisms can modulate both innate and adaptive immune responses. Host-commensal interactions also have an effect on the developing immune system in infants and, subsequently, the occurrence of diseases, such as asthma and atopic dermatitis (AD). Later in life, the cutaneous microbiome contributes to the development and course of skin disease. Accordingly, in patients with AD, a decrease in microbiome diversity correlates with disease severity and increased colonization with pathogenic bacteria, such as S aureus. Early clinical studies suggest that topical application of commensal organisms (eg, Staphylococcus hominis or Roseomonas mucosa) reduces AD severity, which supports an important role for commensals in decreasing S aureus colonization in patients with AD. Advancing knowledge of the cutaneous microbiome and its function in modulating the course of skin disorders, such as AD, might result in novel therapeutic strategies

Inhaled methoxyflurane (Penthrox®) versus placebo for injury-associated analgesia in children - The MAGPIE trial (MEOF-002): Study protocol for a randomised controlled trial

BackgroundPain from injuries is one of the commonest symptoms in children attending emergency departments (EDs), and this is often inadequately treated in both the pre-hospital and ED settings, in part due to challenges of continual assessment and availability of easily administered analgesic options. Pain practices are therefore a key research priority, including within the field of paediatric emergency medicine. Methoxyflurane, delivered via a self-administered Penthrox® inhaler, belongs to the fluorinated hydrocarbon group of volatile anaesthetics and is unique among the group in having analgesic properties at low doses. Despite over 30 years of clinical acute analgesia use, and a large volume of evidence supporting its safety and efficacy, there is a paucity of randomised controlled trial data for Penthrox®.MethodsThis is an international multi-centre randomised, double-blind, placebo-controlled phase III trial assessing the efficacy and safety of methoxyflurane delivered via the Penthrox® inhaler for the management of moderate to severe acute traumatic pain in children and young people aged 6–17 years. Following written informed consent, eligible participants are randomised to self-administer either inhaled methoxyflurane (maximum dose of 2 × 3 ml) or normal saline placebo (maximum dose 2 × 5 ml). Patients, treating clinicians and research nurses are blinded to the treatment. The primary outcome is the change in pain intensity at 15 min after the commencement of treatment, as measured by the Visual Analogue Scale (VAS) or the Wong-Baker FACES® Pain Rating scale, with the latter converted to VAS values. Secondary outcome measures include the number and proportion of responders who achieve a 30% reduction in VAS score compared to baseline, rescue medication requested, time and number of inhalations to first pain relief, global medication performance assessment by the patient, clinician and research nurse, and evaluation of adverse events experienced during treatment and during the subsequent 14 ± 2 days. The primary analysis will be by intention to treat. The total sample size is 110 randomised and treated patients per treatment arm.DiscussionThe Methoxyflurane AnalGesia for Paediatric InjuriEs (MAGPIE) trial will provide efficacy and safety data for methoxyflurane administered via the Penthrox® inhaler, in children and adolescents who present to EDs with moderate to severe injury-related pain.Trial registrationEudraCT, 2016–004290-41. Registered on 11 April 2017.ClinicalTrials.gov, NCT03215056. Registered on 12 July 2017

Changes in nano-mechanical properties of human epidermal cornified cells in children with atopic dermatitis

Background: Impaired skin barrier is an important etiological factor in atopic dermatitis (AD). The structural protein filaggrin (FLG) plays a major role in maintenance of the competent skin barrier and its deficiency is associated with enhanced susceptibility to mechanical injury. Here we examined biomechanical characteristics of the corneocytes in children with AD and healthy controls. Methods: We recruited 20 children with AD and 7 healthy children. They were genotyped for filaggrin gene ( FLG) loss-of-function mutations. Stratum corneum was collected from clinically unaffected skin by adhesive tapes. Cell stiffness (apparent elastic modulus, Ea) was determined by atomic force microscopy and filaggrin degradation products (NMF) by liquid chromatography. Skin barrier function was assessed through trans-epidermal water loss (TEWL) and disease severity by the SCORing Atopic Dermatitis (SCORAD) tool. Results: Corneocytes collected from AD patients showed a decreased elastic modulus which was strongly correlated with NMF and TEWL, but not with SCORAD. As compared with healthy controls, AD patients had reduced TEWL and NMF levels regardless of FLG mutations. NMF was strongly correlated with TEWL. Conclusion: Our findings demonstrate that AD patients have decreased corneocyte stiffness which correlates with reduced levels of filaggrin degradation products, NMF and skin barrier function. Altered mechanical properties of the corneocytes likely contribute to the loss of mechanical integrity of the SC and to reduced skin barrier function in AD

Filaggrin-stratified transcriptomic analysis of pediatric skin identifies mechanistic pathways in patients with atopic dermatitis

BackgroundAtopic dermatitis (AD; eczema) is characterized by a widespread abnormality in cutaneous barrier function and propensity to inflammation. Filaggrin is a multifunctional protein and plays a key role in skin barrier formation. Loss-of-function mutations in the gene encoding filaggrin (FLG) are a highly significant risk factor for atopic disease, but the molecular mechanisms leading to dermatitis remain unclear.ObjectiveWe sought to interrogate tissue-specific variations in the expressed genome in the skin of children with AD and to investigate underlying pathomechanisms in atopic skin.MethodsWe applied single-molecule direct RNA sequencing to analyze the whole transcriptome using minimal tissue samples. Uninvolved skin biopsy specimens from 26 pediatric patients with AD were compared with site-matched samples from 10 nonatopic teenage control subjects. Cases and control subjects were screened for FLG genotype to stratify the data set.ResultsTwo thousand four hundred thirty differentially expressed genes (false discovery rate, P < .05) were identified, of which 211 were significantly upregulated and 490 downregulated by greater than 2-fold. Gene ontology terms for “extracellular space” and “defense response” were enriched, whereas “lipid metabolic processes” were downregulated. The subset of FLG wild-type cases showed dysregulation of genes involved with lipid metabolism, whereas filaggrin haploinsufficiency affected global gene expression and was characterized by a type 1 interferon–mediated stress response.ConclusionThese analyses demonstrate the importance of extracellular space and lipid metabolism in atopic skin pathology independent of FLG genotype, whereas an aberrant defense response is seen in subjects with FLG mutations. Genotype stratification of the large data set has facilitated functional interpretation and might guide future therapy development

Systemic and stratum corneum biomarkers of severity in infant atopic dermatitis include markers of innate and T helper cell-related immunity and angiogenesis

BACKGROUND: Biomarkers of atopic dermatitis (AD) are largely lacking, especially in infant AD. Those that have been examined to date have focused mostly on serum cytokines with few on non-invasive biomarkers in the skin. OBJECTIVES: We aimed to explore biomarkers obtainable from non-invasive sampling of infant skin. We compared these to plasma biomarkers and structural and functional measures of the skin barrier. METHODS: We recruited 100 infants at first presentation with AD, who were treatment naïve to topical or systemic anti-inflammatory therapies and 20 healthy children. We sampled clinically unaffected skin by tape stripping the stratum corneum (SC). Multiple cytokines and chemokines and natural moisturizing factors (NMF) were measured in the SC and plasma. We recorded disease severity and skin barrier function. RESULTS: 19 SC and 12 plasma biomarkers showed significant difference between healthy and AD skin. Some biomarkers were common to both the SC and plasma, and others were compartment-specific. Identified biomarkers of AD severity included Th2 skewed markers (IL-13, CCL17, CCL22, IL-5), markers of innate activation (IL-18, Il-1α, IL1β, CXCL8), angiogenesis (Flt-1, VEGF) and others (sICAM-1, vCAM-1, IL-16, IL-17A). CONCLUSIONS: We identified clinically relevant biomarkers of AD, including novel markers, easily sampled and typed in infants. These markers may provide objective assessment of disease severity and suggest new therapeutic targets, or response measurement targets for AD. Future studies will be required to determine if these biomarkers, seen in very early AD, can predict disease outcomes or comorbidities

Intragenic copy number variation within filaggrin contributes to the risk of atopic dermatitis with a dose-dependent effect

Loss-of-function variants within the filaggrin gene (FLG) increase the risk of atopic dermatitis. FLG also demonstrates intragenic copy number variation (CNV), with alleles encoding 10, 11, or 12 filaggrin monomers; hence, CNV may affect the amount of filaggrin expressed in the epidermis. A total of 876 Irish pediatric atopic dermatitis cases were compared with 928 population controls to test the hypothesis that CNV within FLG affects the risk of atopic dermatitis independently of FLG-null mutations. Cases and controls were screened for CNV and common FLG-null mutations. In this population the 11-repeat allele was most prevalent (allele frequency 51.5%); the 10-repeat allele frequency was 33.9% and the 12-repeat allele frequency was 14.6%. Having excluded FLG mutation carriers, the control group had a significantly higher number of repeats than cases (χ2P=0.043), and the odds ratio of disease was reduced by a factor of 0.88 (95% confidence interval 0.78–0.98, P=0.025) for each additional unit of copy number. Breakdown products of filaggrin were quantified in tape-stripped stratum corneum from 31 atopic dermatitis patients and urocanic acid showed a positive correlation with total copy number. CNV within FLG makes a significant, dose-dependent contribution to atopic dermatitis risk, and therefore treatments to increase filaggrin expression may have therapeutic utility

Survey and scoping of wildcat priority areas

This report summarises the findings of three complementary projects commissioned by SNH to inform the selection of Priority Areas for wildcat conservation; as proposed in the Scottish Wildcat Conservation Action Plan 2013. The scoping projects combined field surveys, taxonomic and genetic assessments, population modelling and a questionnaire survey of public attitudes to wildcat conservation measures. The report makes a recommendations for six wildcat Priority Areas from the nine areas pre-selected by SNH for survey. The sites recommended as Priority Areas all had evidence of cats that were classified as wildcats based on their appearance. However, domestic cats or hybrids (between domestic cats and wildcats) were also found, highlighting the need for conservation actions to reduce the risks they pose to wildcats from hybridisation and disease