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.

Secukinumab responses vary across the spectrum of congenital ichthyosis in adults.

IMPORTANCE: Treatment of congenital ichthyoses primarily focuses on reversing skin scaling and is not pathogenesis based. Recent studies showed Th17 immune skewing, as in psoriasis, across the spectrum of ichthyosis, suggesting that targeting this pathway might broadly reduce disease severity. OBJECTIVE: To determine whether secukinumab, an IL-17A inhibitor, can improve ichthyosis across several congenital ichthyosis subtypes. DESIGN: Exploratory 16-week double-blind, randomized, placebo-controlled trial comparing secukinumab 300 mg every 4wks to placebo (1:1 randomization) in adults with the four major congenital ichthyosis subtypes (NCT03041038), followed by a 16-week open-label phase to evaluate response of the placebo-first group and a 20-week extension for safety. Significant differences in secukinumab- vs. placebo-treated subjects at Wk16 in the Ichthyosis Area Severity Index (IASI) score and lack of increased mucocutaneous bacterial and/or fungal infections were the co-primary efficacy and safety endpoints, respectively. SETTING: Two tertiary referral centers: Northwestern University Feinberg School of Medicine, Chicago, and Mount Sinai Icahn School of Medicine, New York. PARTICIPANTS: Twenty subjects ≥ 18 yo with genotype-confirmed epidermolytic ichthyosis, Netherton syndrome, lamellar ichthyosis, or congenital ichthyosiform erythroderma with at least moderate erythroderma. RESULTS: IL-17A inhibition did not significantly reduce severity or increase mucocutaneous infections among the 18 who completed the 16-week double-blind phase. Five patients with 29-50% clinical improvement at Wk32 requested drug continuation. Th17-related biomarkers were not significantly reduced vs. baseline or placebo-treated levels. LIMITATIONS: Small sample size; heterogeneous ichthyosis subsets. CONCLUSION: IL-17 inhibition with secukinumab is safe, but not efficacious across the spectrum of adult ichthyoses. GOV REGISTRATION NUMBER: NCT03041038; first posted on 02/02/2017.

Delayed type hypersensitivity reactions to various allergens may differently model inflammatory skin diseases.

BACKGROUND: Treatment of inflammatory skin diseases, including atopic dermatitis (AD) and psoriasis, is undergoing transformative changes, highlighting the need to develop experimental models of skin inflammation in humans to predict treatment responses. METHODS: We topically or intradermally administered four common sensitizers (dust mite (DM), diphencyprone (DPCP), nickel (Ni), and purified protein derivative (PPD)) to the backs of 40 healthy patients and the skin hypersensitivity response was biopsied and evaluated using immunohistochemistry, RNA-seq, and RT-PCR. RESULTS: All agents induced strong increases in cellular infiltrates (T-cells and dendritic cells) as compared to untreated skin (p < .05), with variable T helper polarization. Overall, DPCP induced the strongest immune responses across all pathways, including innate immunity (IL-1α, IL-8), Th1 (IFNγ, CXCL10), Th2 (IL-5, CCL11), and Th17 (CAMP/LL37) products, as well as the highest regulatory tone (FOXP3, IL-34, IL-37) (FDR <0.01). Nickel induced Th17 (IL-17A), Th1 (CXCL10) and Th2 (IL-4R) immune responses to a lesser extent than DPCP (p < .05). PPD induced predominantly Th1 (IFNγ, CXCL10, STAT1) and Th17 inflammation (IL-17A) (p < .05). DM induced modulation of Th2 (IL-13, CCL17, CCL18), Th22 (IL-22), and Th17/Th22 (S100A7/9/12) pathways (p < .05). Barrier defects that characterize both AD and psoriasis were best modeled by DPCP and Ni, followed by PPD, including downregulation of terminal differentiation (FLG, FLG2, LOR, LCEs), tight junction (CLDN1/CLDN8), and lipid metabolism (FA2H, FABP7)-related markers. CONCLUSION: Our data imply that DPCP induced the strongest immune response across all pathways, and barrier defects characteristic of AD and psoriasis.

Transcriptomic Profiling of Tape-Strips From Moderate to Severe Atopic Dermatitis Patients Treated With Dupilumab.

BACKGROUND: Tape-strips are a minimally invasive approach to characterize skin biomarkers in atopic dermatitis (AD). However, they have not yet been used for tracking gene expression changes with systemic treatment. OBJECTIVE: The aim of the study was to evaluate gene expression changes and therapeutic response biomarkers in AD patients before and after dupilumab (interleukin 4Rα antibody) treatment using tape-strips to obtain epidermal tissue for analysis. METHODS: Lesional and nonlesional tape-stripped skin was sampled from 18 AD patients before and after dupilumab treatment and from 17 healthy subjects and analyzed by RNA-seq. RESULTS: At baseline, we detected 6745 and 4859 differentially expressed genes between lesional and nonlesional skin versus normal, respectively, whereas 841 and 977 genes were differentially expressed after treatment, respectively (fold change >1.5 and false discovery rate <0.05). Tape-strips captured significant modulation with dupilumab in key AD immune (eg, C-C motif chemokine ligand 13 [CCL13], CCL17, CCL18) and barrier (eg, periplakin, FA2H) biomarkers. Changes in biomarkers (CCL20, interleukin 34, FABP7) were also significantly correlated with clinical disease improvements (Eczema Area and Severity Index; R > 0.5 or R < -0.4, P < 0.05). CONCLUSIONS: This real-life study represents the first comprehensive RNA-seq molecular profiling of tape-strips from moderate to severe AD patients after dupilumab therapy. Analysis of tape strip specimens detected significant gene expression changes in key AD biomarkers with dupilumab treatment, suggesting that this approach may be useful to monitor therapeutic responses in inflammatory skin diseases.

Immune and barrier characterization of atopic dermatitis skin phenotype in Tanzanian patients.

BACKGROUND: Atopic dermatitis (AD) is a common disease, with particularly high prevalence found in Africa. It is increasingly recognized that patients with AD of different ethnic backgrounds have unique molecular signatures in the skin, potentially accounting for treatment response variations. Nevertheless, the skin profile of patients with AD from Africa is unknown, hindering development of new treatments targeted to this patient population. OBJECTIVE: To characterize the skin profile of patients with AD from Africa. METHODS: Gene expression studies, including RNA sequencing (using threshold of fold change of >2 and false discovery rate of <0.05) and real-time polymerase chain reaction, were performed on skin biopsies of Tanzanian patients with moderate-to-severe AD and controls. RESULTS: Tanzanian AD skin presented robust up-regulations of multiple key mediators of both T helper 2 (TH2) (interleukin 13 [IL-13], IL-10, IL-4R, CCL13,CCL17,CCL18,CCL26) and TH22 (IL22, S100As) pathways. Markers related to TH17 and IL-23 (IL-17A, IL-23A, IL-12, PI3, DEFB4B) and TH1 (interferon gamma, CXCL9,CXCL10,CXCL11) were also significantly overexpressed in AD tissues (FDR<.05), albeit to a lesser extent. IL-36 isoforms revealed substantial up-regulations in African skin. The barrier fingerprint of Tanzanian AD revealed no suppression of hallmark epidermal barrier differentiation genes, such as filaggrin, loricrin, and periplakin, with robust attenuation of lipid metabolism genes (ie, AWAT1). CONCLUSION: The skin phenotype of Tanzanian patients with AD is consistent with that of African Americans, exhibiting dominant TH2 and TH22 skewing, minimal dysregulation of terminal differentiation, and even broader attenuation of lipid metabolism-related products. These data highlight the unique characteristic of AD in Black individuals and the need to develop unique treatments targeting patients with AD from these underrepresented populations.

Vascular inflammation in moderate-to-severe atopic dermatitis is associated with enhanced Th2 response.

BACKGROUND: In atopic dermatitis (AD), some studies have shown an association with increased cardiovascular disease in certain populations. However, other investigations found modest or no association. Despite conflicting results, molecular profiling studies in both AD skin and blood have demonstrated upregulation of atherosclerosis and cardiovascular risk-related markers. However, the underlying mechanisms connecting AD to vascular inflammation/atherosclerosis are unknown. In this study, we aim to determine factors associated with vascular inflammation/atherosclerosis in AD patients. METHODS: We used 18-FDG PET-CT to characterize vascular inflammation in AD patients and healthy subjects. In parallel, we assessed their skin and blood immune profiles to determine AD-related immune biomarkers associated with vascular inflammation. We also assessed levels of circulating microparticles, which are known to be associated with increased cardiovascular risk. RESULTS: We found significant correlations between vascular inflammation and Th2-related products in skin and blood of AD patients as well as atherosclerosis-related markers that were modulated by dupilumab. Circulating levels of endothelial microparticles were significantly higher in severe AD patients and tended to correlate with vascular inflammation assessed by PET-CT. CONCLUSION: Vascular inflammation in AD is associated with enhanced Th2 response and clinical severity, which may explain cardiovascular comorbidities observed in select AD populations. Larger prospective studies are needed to further evaluate vascular inflammation and cardiovascular events and mortality in AD patients. Finally, as dupilumab treatment demonstrated significant modulation of atherosclerosis-related genes in AD patients compared to placebo, these data suggest that modulation of vascular inflammation with systemic treatment should be explored in patients with AD.

The molecular features of normal and atopic dermatitis skin in infants, children, adolescents, and adults.

BACKGROUND: Although atopic dermatitis (AD) often presents in infancy and persists into adulthood, comparative characterization of AD skin among different pediatric age groups is lacking. OBJECTIVE: 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. METHODS: We performed gene expression analyses by RNA-sequencing and real-time PCR (RT-PCR) and protein expression analysis using immunohistochemistry. RESULTS: TH2/TH22 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. TH17 inflammation presented a 2-peak curve, with highest increases in infants (including IL-17A and IL-17F), followed by adults. TH1 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 TH2/TH22-related markers in all pediatric age groups. CONCLUSIONS: The shared signature of AD across ages is TH2/TH22-skewed, yet differential expression of specific TH2/TH22-related genes, other TH pathways, and barrier-related genes portray heterogenetic, age-specific molecular fingerprints.

Tape strips detect distinct immune and barrier profiles in atopic dermatitis and psoriasis.

BACKGROUND: 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. OBJECTIVE: 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. METHODS: 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. RESULTS: 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 TH2 skewing (IL-13, CCL17/TARC, and CCL18), whereas psoriasis was characterized by higher levels of expression of TH17-related (IL-17A/F and IL-36A/IL-36G), TH1-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. CONCLUSION: 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.

Mild atopic dermatitis lacks systemic inflammation and shows reduced nonlesional skin abnormalities.

BACKGROUND: Molecular studies in atopic dermatitis (AD) are largely restricted to patients with moderate-to-severe disease. OBJECTIVE: Our aim was to evaluate skin and blood abnormalities in mild, moderate, and severe AD. METHODS: 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. RESULTS: 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 TH2 cell-, TH22 cell-, TH1 cell-, and TH17 cell-related mediators demonstrated incremental elevations with increasing disease severity, in both lesional and nonlesional skin. Whereas the levels of the TH2 (IL13, CCL17, and CCL26) and TH22 (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 TH1 cell (IFNG, CXCL9, and CXCL10) and TH17 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 TH1 cell-, TH2 cell-, and TH17 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. CONCLUSION: Mild and limited AD show high levels of TH2/TH22 cell activation that is primarily localized to skin lesions and lacks the systemic inflammation of moderate and severe disease.

Tape strips from early-onset pediatric atopic dermatitis highlight disease abnormalities in nonlesional skin.

BACKGROUND: Skin biopsies promote our understanding of atopic dermatitis/AD pathomechanisms in infants/toddlers with early-onset AD, but are not feasible in pediatric populations. Tape strips are an emerging, minimally invasive alternative, but global transcriptomic profiling in early pediatric AD is lacking. We aimed to provide global lesional and nonlesional skin profiles of infants/toddlers with recent-onset, moderate-to-severe AD using tape strips. METHODS: Sixteen tape strips were collected for RNA-seq profiling from 19 infants/toddlers (<5 years old; lesional and nonlesional) with early-onset moderate-to-severe AD (≤6 months) and 17 healthy controls. RESULTS: We identified 1829 differentially expressed genes/DEGs in lesional AD and 662 DEGs in nonlesional AD, vs healthy skin (fold-change ≥2, FDR <0.05), with 100% sample recovery. Both lesional and nonlesional skin showed significant dysregulations of Th2 (CCL17 and IL4R) and Th22/Th17 (IL36G, CCL20, and S100As)-related genes, largely lacking significant Th1-skewing. Significant down-regulation of terminal differentiation (FLG and FLG2), lipid synthesis/metabolism (ELOVL3 and FA2H), and tight junction (CLDN8) genes were primarily seen in lesional AD. Significant negative correlations were identified between Th2 measures and epidermal barrier gene-subsets and individual genes (FLG with IL-4R and CCL17; r < -0.4, P < .05). Significant correlations were also identified between clinical measures (body surface area/BSA, pruritus ADQ, and transepidermal water loss/TEWL) with immune and barrier mRNAs in lesional and/or nonlesional AD (FLG/FLG2 with TEWL; r < -0.4, P < .05). CONCLUSION: RNA-seq profiling using tape strips in early-onset pediatric AD captures immune and barrier alterations in both lesional and nonlesional skin. Tape strips provide insight into disease pathomechanisms and cutaneous disease activity.

RNA Sequencing Keloid Transcriptome Associates Keloids With Th2, Th1, Th17/Th22, and JAK3-Skewing.

Keloids are disfiguring, fibroproliferative growths and their pathogenesis remains unclear, inhibiting therapeutic development. Available treatment options have limited efficacy and harbor safety concerns. Thus, there is a great need to clarify keloid pathomechanisms that may lead to novel treatments. In this study, we aimed to elucidate the profile of lesional and non-lesional keloid skin compared to normal skin. We performed gene (RNAseq, qRT-PCR) and protein (immunohistochemistry) expression analyses on biopsy specimens obtained from lesional and non-lesional skin of African American (AA) keloid patients compared to healthy skin from AA controls. Fold-change≥2 and false-discovery rate (FDR)<0.05 was used to define significance. We found that lesional versus normal skin showed significant up-regulation of markers of T-cell activation/migration (ICOS, CCR7), Th2- (IL-4R, CCL11, TNFSF4/OX40L), Th1- (CXCL9/CXCL10/CXCL11), Th17/Th22- (CCL20, S100As) pathways, and JAK/STAT-signaling (JAK3) (false-discovery rate [FDR]<0.05). Non-lesional skin also exhibited similar trends. We observed increased cellular infiltrates in keloid tissues, including T-cells, dendritic cells, mast cells, as well as greater IL-4rα+, CCR9+, and periostin+ immunostaining. In sum, comprehensive molecular profiling demonstrated that both lesional and non-lesional skin show significant immune alternations, and particularly Th2 and JAK3 expression. This advocates for the investigation of novel treatments targeting the Th2 axis and/or JAK/STAT-signaling in keloid patients.

Tape-Strip Proteomic Profiling of Atopic Dermatitis on Dupilumab Identifies Minimally Invasive Biomarkers.

Tape-stripping is a minimally invasive approach for skin sampling that captures the cutaneous immune/barrier abnormalities in atopic dermatitis (AD). However, tape-strips have not been used to evaluate molecular changes with therapeutic targeting. In this study, we sought to characterize the proteomic signature of tape-strips from AD patients, before and after dupilumab therapy. Twenty-six AD patients were treated with every-other-week dupilumab 300 mg for 16 weeks. Tape-strips from lesional and non-lesional skin were collected before and after treatment, and analyzed with the Olink proteomic assay. Using criteria of fold-change>1.5 and FDR < 0.05, 136 proteins significantly decreased after dupilumab treatment, corresponding to an overall mean improvement of 66.2% in the lesional vs. non-lesional AD proteome. Significant decreases after dupilumab were observed in immune markers related to general inflammation (MMP12), Th2 (CCL13/CCL17), Th17/Th22 (IL-12B, CXCL1, S100A12), and innate immunity (IL-6, IL-8, IL-17C), while the Th1 chemokines CXCL9/CXCL10 remained elevated. Proteins related to atherosclerosis/cardiovascular risk (e.g., SELE/E-selectin, IGFBP7, CHIT1/ chitotriosidase-1, AXL) also significantly decreased after treatment. Dupilumab therapy suppressed AD-related immune biomarkers and atherosclerosis/cardiovascular risk proteins. Tape-strip proteomics may be useful for monitoring therapeutic response in real-life settings, clinical trials, and longitudinal studies for AD and beyond.

Endophenotypic Variations of Atopic Dermatitis by Age, Race, and Ethnicity.

Atopic dermatitis (AD) is a heterogeneous disease with unique clinical manifestations across age groups and race/ethnicities. Characteristic molecular mechanisms, known as endotypes, including IgE level, status of epidermal barrier genes, and differential cytokine axes activation in the background of TH2 upregulation, are also implicated. In adults, the TH22, TH17, and TH1 pathways are involved, and a weakened epidermal barrier is characteristic. In contrast, pediatric patients exhibit less TH1 activation, and defects in epidermal lipid metabolism contribute to their barrier defect. European American patients are characterized by higher differential TH2/TH22 activation, lower expression of the TH1/TH17 axes, and suppression of filaggrin (FLG) and loricrin gene expressions. Asian patients have accentuated polarity of the TH22/TH17 pathways, and also exhibit epidermal barrier defects despite relative maintenance of FLG and loricrin expression. African American patients do not exhibit FLG mutations and have distinct attenuation of TH17/TH1 axes activation. Dissecting the molecular basis of AD endotypes has provided an important framework upon which targeted therapeutics are being developed. An increased understanding of these subtypes and the alteration of biomarkers that correlate with disease can ultimately push AD treatment in an era of personalized medicine.

Type 2 immunity in the skin and lungs.

There has been extensive progress in understanding the cellular and molecular mechanisms of inflammation and immune regulation in allergic diseases of the skin and lungs during the last few years. Asthma and atopic dermatitis (AD) are typical diseases of type 2 immune responses. interleukin (IL)-25, IL-33, and thymic stromal lymphopoietin are essential cytokines of epithelial cells that are activated by allergens, pollutants, viruses, bacteria, and toxins that derive type 2 responses. Th2 cells and innate lymphoid cells (ILC) produce and secrete type 2 cytokines such as IL-4, IL-5, IL-9, and IL-13. IL-4 and IL-13 activate B cells to class-switch to IgE and also play a role in T-cell and eosinophil migration to allergic inflammatory tissues. IL-13 contributes to maturation, activation, nitric oxide production and differentiation of epithelia, production of mucus as well as smooth muscle contraction, and extracellular matrix generation. IL-4 and IL-13 open tight junction barrier and cause barrier leakiness in the skin and lungs. IL-5 acts on activation, recruitment, and survival of eosinophils. IL-9 contributes to general allergic phenotype by enhancing all of the aspects, such as IgE and eosinophilia. Type 2 ILC contribute to inflammation in AD and asthma by enhancing the activity of Th2 cells, eosinophils, and their cytokines. Currently, five biologics are licensed to suppress type 2 inflammation via IgE, IL-5 and its receptor, and IL-4 receptor alpha. Some patients with severe atopic disease have little evidence of type 2 hyperactivity and do not respond to biologics which target this pathway. Studies in responder and nonresponder patients demonstrate the complexity of these diseases. In addition, primary immune deficiency diseases related to T-cell maturation, regulatory T-cell development, and T-cell signaling, such as Omenn syndrome, severe combined immune deficiencies, immunodysregulation, polyendocrinopathy, enteropathy, X-linked syndrome, and DOCK8, STAT3, and CARD11 deficiencies, help in our understanding of the importance and redundancy of various type 2 immune components. The present review aims to highlight recent advances in type 2 immunity and discuss the cellular sources, targets, and roles of type 2 mechanisms in asthma and AD.

Efficacy of biologics in atopic dermatitis.

Introduction: Atopic dermatitis (AD) is a heterogeneous disease. Recent advancements in understanding AD pathogenesis resulted in the exponential expansion of its therapeutic pipeline, particularly following the success and FDA-approval of dupilumab. Different phenotypes of AD by age and ethnicity have also recently been described and clinical studies of emerging treatments will further clarify the role of each cytokine pathway in AD.Areas covered: We review the impressive repertoire of biologics for treatment of moderate-to-severe AD, including those targeting Th2, Th22, Th17/IL-23 and IgE. We highlight the scientific rationale behind each approach and provide a discussion of the most recent clinical efficacy and safety data.Expert opinion: AD is a complex disease and recent research has identified numerous endotypes, reinforcing the rationale for developing targeted therapeutics to antagonize these factors. Dupilumab has revolutionized AD treatment and its mechanistic studies also offer crucial insight into AD pathogenesis. Nevertheless, this biologic does not work for everyone, highlighting the need for a more precise approach to address the unique immune fingerprints of each AD subset. Ultimately targeted therapeutics will complement our understanding of the AD molecular map and help push AD management into an era of personalized medicine.