Total eosinophil count as a biomarker for therapeutic effects of upadacitinib in atopic dermatitis over 48 weeks.

Background: Atopic dermatitis (AD) is a chronic skin disease characterized by type 2-skewed immune responses, and significantly influenced by cytokines dependent on Janus kinases (JAKs). Upadacitinib, a JAK1 inhibitor, is effective for moderate-to-severe AD. This study aims to identify biomarkers that reflect long-term therapeutic effects of upadacitinib 15 mg or 30 mg. Methods: A retrospective study from August 2021 to July 2023 included 213 AD patients treated with upadacitinib 15 mg and 70 AD patients with 30 mg. We analyzed eczema area and severity index (EASI), peak pruritus-numerical rating scale (PP-NRS), serum immunoglobulin E (IgE), thymus and activation-regulated chemokine (TARC), lactate dehydrogenase (LDH), and total eosinophil count (TEC) at weeks 0, 4, 12, 24, 36, and 48 of treatment. Results: Both treatments with upadacitinib 15 mg and 30 mg significantly reduced EASI and PP-NRS scores over week 4 to 48 compared to baseline. Upadacitinib 15 mg or 30 mg treatment significantly decreased TEC compared to baseline through week 4 to 36 or week 4 to 48, respectively. The percent reduction of TEC correlated with those of EASI and PP-NRS through week 4 to 48 of treatment with upadacitinib 15 mg, or through week 12 to 48 with 30 mg, respectively. After adjusting for % reductions of other laboratory markers, the significance of correlations was preserved at weeks 36 and 48 of 15 mg treatment, while at weeks 4 and 36 of 30 mg treatment. Conclusion: The % reduction of TEC correlated with those of EASI and PP-NRS during upadacitinib treatment, indicating its potential as a biomarker reflecting treatment responses to upadacitinib in AD patients. However, the variability of significant correlation during treatment indicates that further inspection is needed for its usefulness in monitoring responses to upadacitinib treatment for AD.

PDE4D and miR-203 are promising biomarkers for canine atopic dermatitis.

BACKGROUND: Canine atopic dermatitis (CAD) is a common genetically predisposed, inflammatory, and pruritic skin disorder that affects dogs globally. To date, there are no specific biomarkers available to diagnose CAD, and the current diagnosis is based on a combination of criteria including patient history, clinical signs, and exclusion of other relevant differential diagnoses. METHODS AND RESULTS: We examined the gene expression of phosphodiesterase 4D (PDE4D) in peripheral blood mononuclear cells (PBMCs), as well as miR-203 and miR-483 in plasma, in three groups: healthy dogs, CAD dogs, and other inflammatory pruritic skin diseases (OIPSD) such as pemphigus foliaceus, scabies, cutaneous lymphoma, and dermatophytosis. Our results showed that PDE4D gene expression in the CAD group is statistically higher compared to those in the healthy and OIPSD groups, suggesting PDE4D may be a specific marker for CAD. Nevertheless, no correlation was found between PDE4D gene expression levels and the lesion severity gauged by CAD severity index-4 (CADESI-4). We also showed that miR-203 is a generic marker for clinical dermatitis and differentiates both CAD and OIPSD inflammatory conditions from healthy controls. CONCLUSIONS: We show that PDE4D is a potential marker to differentiate CAD from non-atopic healthy and OIPSD while miR-203 may be a potential marker for general dermatologic inflammation. Future study of PDE4D and miR-203 on a larger scale is warranted.

Screening mitochondria-related biomarkers in skin and plasma of atopic dermatitis patients by bioinformatics analysis and machine learning.

Background: There is a significant imbalance of mitochondrial activity and oxidative stress (OS) status in patients with atopic dermatitis (AD). This study aims to screen skin and peripheral mitochondria-related biomarkers, providing insights into the underlying mechanisms of mitochondrial dysfunction in AD. Methods: Public data were obtained from MitoCarta 3.0 and GEO database. We screened mitochondria-related differentially expressed genes (MitoDEGs) using R language and then performed GO and KEGG pathway analysis on MitoDEGs. PPI and machine learning algorithms were also used to select hub MitoDEGs. Meanwhile, the expression of hub MitoDEGs in clinical samples were verified. Using ROC curve analysis, the diagnostic performance of risk model constructed from these hub MitoDEGs was evaluated in the training and validation sets. Further computer-aided algorithm analyses included gene set enrichment analysis (GSEA), immune infiltration and mitochondrial metabolism, centered on these hub MitoDEGs. We also used real-time PCR and Spearman method to evaluate the relationship between plasma circulating cell-free mitochondrial DNA (ccf-mtDNA) levels and disease severity in AD patients. Results: MitoDEGs in AD were significantly enriched in pathways involved in mitochondrial respiration, mitochondrial metabolism, and mitochondrial membrane transport. Four hub genes (BAX, IDH3A, MRPS6, and GPT2) were selected to take part in the creation of a novel mitochondrial-based risk model for AD prediction. The risk score demonstrated excellent diagnostic performance in both the training cohort (AUC = 1.000) and the validation cohort (AUC = 0.810). Four hub MitoDEGs were also clearly associated with the innate immune cells' infiltration and the molecular modifications of mitochondrial hypermetabolism in AD. We further discovered that AD patients had considerably greater plasma ccf-mtDNA levels than controls (U = 92.0, p< 0.001). Besides, there was a significant relationship between the up-regulation of plasma mtDNA and the severity of AD symptoms. Conclusions: The study highlights BAX, IDH3A, MRPS6 and GPT2 as crucial MitoDEGs and demonstrates their efficiency in identifying AD. Moderate to severe AD is associated with increased markers of mitochondrial damage and cellular stress (ccf=mtDNA). Our study provides data support for the variation in mitochondria-related functional characteristics of AD patients.

Minipuberty period of children with atopic dermatitis compared to healthy children.

Background/aim: Atopic dermatitis (AD) is an inflammatory, pruritic, noncontagious, chronic relapsing skin disease. Skin barrier abnormalities, excessive T helper 2 activity, and immune dysregulation are held responsible. Androgens have a negative effect on the integrity of the epidermal skin barrier, while estrogen has a positive effect. We aimed to investigate whether hormones make a difference between healthy children and children with AD during minipuberty. Materials and methods: A total of 96 infants (postnatal 4-13 weeks), 48 diagnosed with AD and 48 controls, were included. Each group consisted of 23 girls (47.9%) and 25 boys (52.1%). Anthropometric examinations and hormone measurements were compared. Results: The two groups, having similar age, sex, body mass index, and weight-for-length standard deviation scores, were compared. Serum free thyroxine (FT4) levels were found to be lower and insulin-like growth factor binding protein-3 (IGFBP3) levels were found to be higher in children with AD (p < 0.001 and p = 0.038, respectively). In girls with AD, estradiol, FT4, and insulin-like growth factor-1 (IGF-1) levels were found to be lower, but thyroid-stimulating hormone (TSH) levels were found to be higher (p = 0.023, p < 0.001, p = 0.038, and p = 0.034, respectively). In boys with AD, the FT4 level was found to be lower (p = 0.023). Serum FT4 and TSH levels were within normal reference ranges in all comparisons. Conclusion: Especially in girls with AD, decreased estradiol and IGF-1 levels were observed compared to the controls during minipuberty. In the logistic regression model, decreased levels of serum estradiol, dehydroepiandrosterone sulfate, FT4, and IGF-1, and increased levels of IGFBP3 were associated with an increased likelihood of exhibiting atopic dermatitis.

Real-world effectiveness and safety of abrocitinib in 12 Japanese patients with atopic dermatitis and transcriptome analysis with peripheral blood.

Atopic dermatitis (AD) is a common chronic inflammatory skin disease characterized by recurrent, pruritic, and localized eczema. Various types of new drugs have been recently investigated for treating AD. The efficacy and safety of abrocitinib in treating AD has been reported in clinical trials, but the real-world data from Japan has not been reported. Herein, we analyzed 12 Japanese patients with AD treated with 100 mg of abrocitinib using our real-world data. We also performed transcriptome analysis with peripheral blood to investigate the effects of abrocitinib on cytokine expressions and inflammatory pathways in AD from three patients. This study included patients with moderate to severe AD treated with abrocitinib at Gunma University Hospital, Japan. All patients were systemic treatment-naïve. All patients received a 100-mg dose of abrocitinib daily, and used strong or very strong topical steroids and moisturizers. The Eczema Area and Severity Index (EASI) response analysis revealed that after 4 weeks, 25% (three of 12) of the cases reached a 75% reduction in the EASI score (EASI-75) and a 90% reduction in the EASI score (EASI-90). After 12 weeks, 83.3.% (10 of 12), 41.6% (five of 12), and 16.7% (two of 12) of the patients reached EASI-50, a 75% reduction in the EASI score (EASI-75), and EASI-90. Peak Pruritus Numerical Rating Scale was achieved in nine patients (75%) at week 12. The most frequent adverse reaction was acne (six cases [50%]). Gene Ontology pathway analysis using Differentially expressed genes from RNA sequencing analysis revealed attenuation of defense responses to biotic stimulus, virus, and cytokines. Th2 cytokine expression was not suppressed, but several chemokines, especially CXCL1, were suppressed by abrocitinib treatment. Our results indicate abrocitinib as a fast-acting and highly antipruritic agent that is effective for moderate skin eruptions.

Associations between cord blood acetaminophen biomarkers and childhood asthma with and without allergic comorbidities.

BACKGROUND: Previous studies have linked prenatal acetaminophen use to increased asthma risk in children. However, none have explored this association while differentiating between asthma cases with and without other allergic conditions or by employing objective biomarkers to assess acetaminophen exposure. OBJECTIVE: To evaluate whether the detection of acetaminophen biomarkers in cord blood is associated with the subgroups of asthma both with and without allergic comorbidities in children. METHODS: Acetaminophen biomarkers, including unchanged acetaminophen and acetaminophen glucuronide, were measured in neonatal cord blood samples from the Boston Birth Cohort. Asthma subgroups were defined on the basis of physician diagnoses of asthma and other allergic conditions (atopic dermatitis and allergic rhinitis). Multinomial regressions were used to evaluate the associations between acetaminophen biomarkers and asthma subgroups, adjusting for multiple confounders, including potential indications for maternal acetaminophen use such as maternal fever. RESULTS: The study included 142 children with asthma and at least 1 other allergic condition, 55 children with asthma but no other allergic condition, and 613 children free of asthma. Detection of acetaminophen in cord blood, reflecting maternal exposure to acetaminophen shortly before delivery, was associated with 3.73 times the odds of developing asthma without allergic comorbidities (95% CI: 1.79-7.80, P = .0004). In contrast, the detection of acetaminophen in cord blood was not associated with an elevated risk of asthma with allergic comorbidities. Analysis of acetaminophen glucuronide yielded consistent results. CONCLUSION: In a prospective birth cohort, cord blood acetaminophen biomarkers were associated with an increased risk of childhood asthma without allergic comorbidities, but were not associated with childhood asthma with allergic comorbidities.

IL-4-induced decrease in both the number and CTLA-4 expression of Treg impairs suppression of Th2 type inflammation in severe atopic dermatitis.

BACKGROUND: Treg plays a pivotal role in the suppression of Th2 cell and the maintenance of immune homeostasis. The precise molecular mechanism underlying the disruption of Treg suppression of Th2 cell and the promotion of Th2 type inflammation in allergic diseases remains elusive. OBJECTIVE: This study aims to investigate the molecular mechanism underlying quantitative and functional changes of Treg in AD. METHODS: The molecular mechanism was investigated using flow cytometry, mRNA sequencing, co-culture experiments, co-immunoprecipitation, chromatin immunoprecipitation, and bisulfite sequencing in vitro or in AD mice model and patients with AD. RESULTS: Increased proportion of Treg was detected in mild and moderate AD. Conversely, characteristic decrease in both the number and CTLA-4 expression of Treg was relevant to serum IL-4 level in severe AD patients, which was verified under a high concentration of IL-4 treatment in vitro. The underlying mechanism is that IL-4/pSTAT6 pathway recruits DNMT1 and HDAC2 to inhibit transcriptional regulation of Foxp3 and CTLA-4 loci. High level of IL-4 impaired the suppression of Treg against Th2 cell differentiation mediated by CTLA-4, and blockade of IL-4Rα signaling in Treg restored Treg number and suppression of Th2 cell in AD model mice and patients with AD. CONCLUSION: The number of Treg is relevant to stratification of severity and serum IL-4 level in patients with AD. Abnormal high level of IL-4 epigenetically triggers a decrease in both the number and CTLA-4 expression of Treg. The reduced expression of CTLA-4 on Treg induced by IL-4 impairs suppression of Th2 cell differentiation.

Comparison of intradermal and serum testing for environmental allergen-specific immunoglobulin E determination in a laboratory colony of cats with naturally acquired atopic syndrome.

BACKGROUND: Allergen testing is used to select antigens included in the desensitisation vaccine. Intradermal skin test (IDT) is the gold standard in cats, yet allergen-specific immunoglobulin (Ig)E serological testing (ASIS) is often used. Feline data are lacking regarding the agreement between IDT and ASIS results. HYPOTHESIS/OBJECTIVES: The first objective of the study was to establish a colony of cats with naturally acquired feline atopic syndrome (FAS). Further objectives were to define their hypersensitivity disorder to detail the allergen tests results, and to assess similarity between the allergen tests. ANIMALS: Thirty-five cats with FAS and 10 control cats. MATERIALS AND METHODS: Enrolled cats went through a five phase-screening and quarantine process before joining the colony. An elimination diet trial was performed on all FAS cats. ASIS and IDT were consecutively performed on all cats under sedation. RESULTS: Reactions to 34 allergens were compiled for the 45 cats. Global sensitivity and specificity of ASIS were 34.7% and 78.9%, respectively. Only flea (ICC = 0.26, p = 0.040) and Dermatophagoides pteronyssinus (ICC = 0.48, p < 0.001) allergens had a significant intraclass correlation (weak agreement). Two FAS cats had negative tests including one cat with a concomitant food allergy. CONCLUSIONS AND CLINICAL RELEVANCE: This study depicts the first reported colony of cats with naturally acquired FAS. This is the first feline study to compare and show the poor agreement between allergen tests with a panel of 34 allergens. This colony also harbours two cats with FAS with negative allergen tests. These may represent the first described cats with an intrinsic form of atopic syndrome.

Antioxidant defense of children and adolescents with atopic dermatitis: Association with disease severity

Background: Atopic dermatitis (AD) is a relapsing, chronic cutaneous inflammatory disease with onset, in general, in early childhood. Chronic skin inflammation is associated with overproduction of reactive oxygen species (ROS) such as superoxide and hydrogen peroxide. Oxidative stress, an imbalance between the production of free radicals and antioxidant defense, results in tissue inflammation due to the upregulation of genes that encode inflammatory cytokines. This condition plays an important role in the pathogenesis of AD. Objective: To compare the antioxidant defense in children and adolescents with AD with that of healthy individuals and to verify the association of antioxidant defense with disease severity and nutritional status. Methods: Cross-sectional study that evaluated 48 children and adolescents with AD and 25 controls for nutritional assessment (body mass index z score [BMIZ] and height for age z score [HAZ]) and levels of vitamins A, C, E, and D, zinc (Zn), copper (Cu), antioxidant enzymes (superoxide dismutase [SOD], catalase [CAT], glutathione peroxidase [GPx]), high-sensitivity C-reactive protein (CRP) and interleukin 33 (IL-33). Results: There was no significant difference in the comparison between AD and control groups for serum levels of vitamins (A, D, C, and E), copper, and antioxidant enzymes. Serum zinc levels were higher in the AD group (β = 24.20; 95% CI 13.95–34.91; P < 0.001) even after adjusting the BMIZ, HAZ, gender, IL-33, and CRP. Children and adolescents with moderate or severe AD compared to mild AD (SCORAD – 36.7±17.4 vs 11.8 ± 3.9; P < 0.001) had lower values of the vitamin E/total lipid ratio (3.68 [0.29;12.63] vs 5.92 [3.27;17.37]; P = 0.013) (AU)

Serum thymus and activation-regulated chemokine (TARC) levels correlate with atopic dermatitis disease severity in patients < 6 months.

Background: Atopic dermatitis (AD) may develop by 6 months of age, and its severity assessment is essential for appropriate treatments. Scoring Atopic Dermatitis (SCORAD) is suggested to evaluate the severity of AD but is cumbersome for routine clinical use. The serum thymus and activation-regulated chemokine (TARC) is used as a marker of AD severity. However, the normal range of the TARC levels varies by age, and its usefulness for the evaluation of AD severity has not been established in patients ages < 6 months. Here, we evaluated the correlation between serum TARC levels and SCORAD scores in early infancy and sought the optimal cutoff level to indicate AD severity. Methods: The subjects were 35 patients with AD (16 girls and 19 boys; 3-5 months of age) who visited our clinic between April 2015 and March 2017. All the patients were physically examined by a board-certified allergist. The AD severity was determined by using the SCORAD, together with serum levels of TARC, total immunoglobulin E (IgE), lactate dehydrogenase, and peripheral eosinophil counts. Receiver operating characteristic curve analysis was performed to determine the cutoff levels of serum TARC to indicate AD severity. Results: Significant correlations were observed between SCORAD scores and the serum TARC levels, peripheral eosinophil counts, and serum IgE levels (r = 0.640, r = 0.723, r = 0.533, respectively). The optimal cutoff levels of serum TARC to indicate mild and severe AD were <3523 pg/mL (area under the curve [AUC] = 0.856) and >6192 pg/mL (AUC = 0.833), respectively. Conclusion: Although this study had limitations, we suggest that serum TARC is useful as a marker of AD severity in patients <6 months of age.

Plasma Levels of Bioactive Vitamin D and A5 Ligands Positively Correlate with Clinical Atopic Dermatitis Markers.

BACKGROUND: Over the past decade, several controversial studies described a relationship between vitamin D and atopic diseases. Low plasma vitamin D levels or even vitamin D deficiency was associated with an increased incidence of atopic disease, postulating that a higher dietary intake of vitamin D may be a beneficial strategy against atopic diseases such as atopic dermatitis (AD). OBJECTIVE: Our aim was to determine the relationship between plasma 25-hydroxyvitamin D3 (25(OH)D3) levels, the levels of the ligand of the vitamin D receptor (VDR) heterodimerization partner as well as the retinoid X receptor (RXR) and the active vitamin A5 derivative 9-cis-13,14-dihydroretinoic acid (9CDHRA) and AD severity. METHODS/RESULTS: Samples from AD patients (n = 20) and healthy volunteers (n = 20) were assessed. In our study, the frequently measured VDR ligand precursor 25(OH)D3 in addition to the VDR-ligand 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) and 9CDHRA displayed no different levels when compared with the plasma of AD patients and healthy volunteers. When performing further correlation studies focusing on AD patients, plasma 25(OH)D3 levels showed a negative correlation with eosinophils in blood (EOS) and SCORing Atopic Dermatitis (SCORAD) values, while 1,25(OH)2D3 and 9CDHRA levels correlated positively with plasma IgE, EOS, and SCORAD values. CONCLUSION: In consequence, the metabolic activation of vitamin D from 25(OH)D3 towards 1,25(OH)2D3 as well as the co-liganding of the RXR by 9CDHRA may be an important signalling mechanism, an important marker for AD development and severity as well as the basis for novel nutritional and pharmaceutical AD treatment options.

Characterization of the L-Arginine/Nitric Oxide Pathway and Oxidative Stress in Pediatric Patients with Atopic Diseases.

INTRODUCTION: L-Arginine (Arg) is a semi-essential amino acid. Constitutive and inducible nitric oxide synthase (NOS) isoforms convert Arg to nitric oxide (NO), a potent vaso- and bronchodilator with multiple biological functions. Atopic dermatitis (AD) and bronchial asthma (BA) are atopic diseases affecting many children globally. Several studies analyzed NO in airways, yet the systemic synthesis of NO in AD and BA in children with BA, AD or both is elusive. METHODS: In a multicenter study, blood and urine were obtained from 130 of 302 participating children for the measurement of metabolites of the Arg/NO pathway (BA 31.5%; AD 5.4%; AD + BA 36.1%; attention deficit hyperactivity disorder (ADHD) 12.3%). In plasma and urine amino acids Arg and homoarginine (hArg), both substrates of NOS, asymmetric dimethylarginine (ADMA) and symmetric dimethylarginine (SDMA), both inhibitors of NOS, dimethylamine (DMA), and nitrite and nitrate, were measured by gas chromatography-mass spectrometry. Malondialdehyde (MDA) was measured in plasma and urine samples to evaluate possible effects of oxidative stress. RESULTS: There were no differences in the Arg/NO pathway between the groups of children with different atopic diseases. In comparison to children with ADHD, children with AD, BA or AD and BA had higher plasma nitrite (p < 0.001) and nitrate (p < 0.001) concentrations, suggesting higher systemic NO synthesis in AD and BA. Urinary excretion of DMA was also higher (p = 0.028) in AD and BA compared to patients with ADHD, suggesting elevated ADMA metabolization. DISCUSSION/CONCLUSION: The Arg/NO pathway is activated in atopic diseases independent of severity. Systemic NO synthesis is increased in children with an atopic disease. Plasma and urinary MDA levels did not differ between the groups, suggesting no effect of oxidative stress on the Arg/NO pathway in atopic diseases.

Unraveling heterogeneity in pediatric atopic dermatitis: Identification of serum biomarker based patient clusters.

BACKGROUND: Increasing evidence shows that pediatric atopic dermatitis (AD) differs from adult AD on a biologic level. Broad biomarker profiling across a wide range of ages of pediatric patients with AD is lacking. OBJECTIVE: Our aim was to identify serum biomarker profiles in children with AD aged 0 to 17 years and compare these profiles with those previously found in adults with AD. METHODS: Luminex multiplex immunoassays were used to measure 145 biomarkers in serum from 240 children with AD (aged 0-17 years). Principal components analysis followed by unsupervised k-means clustering were performed to identify patient clusters. Patients were stratified into age groups (0-4 years, 5-11 years, and 12-17 years) to assess association between age and cluster membership. RESULTS: Children aged 0 to 4 years had the highest levels of TH1 cell-skewing markers and lowest levels of TH17 cell-related markers. TH2 cell-related markers did not differ significantly between age groups. Similar to the pattern in adults, cluster analysis identified 4 distinct pediatric patient clusters (TH2 cell/retinol-dominant, skin-homing-dominant, TH1 cell/TH2 cell/TH17 cell/IL-1-dominant, and TH1 cell/IL-1/eosinophil-inferior clusters). Only the TH1 cell/TH2 cell/TH17 cell/IL-1-dominant cluster resembled 1 of the previously identified adult clusters. Although no association with age or age of onset seemed to be found, disease severity was significantly associated with the skin-homing-dominant cluster. CONCLUSION: Four distinct patient clusters based on serum biomarker profiles could be identified in a large cohort of pediatric patients with AD, of which 1 was similar to previously identified adult clusters. The identification of endotypes driven by distinct underlying immunopathologic pathways might be useful to define pediatric patients with AD who are at risk of persistent disease and may necessitate different targeted treatment approaches.

Azithromycin pretreatment exacerbates atopic dermatitis in trimellitic anhydride-induced model mice accompanied by correlated changes in the gut microbiota and serum cytokines.

Atopic dermatitis (AD) is a common inflammatory skin disease. This study aims to investigate the effect of azithromycin (AZI) pretreatment, a common macrolide-type antibiotic, on the trimellitic anhydride (TMA) induced AD-like symptoms in mice. AZI (25 mg/kg, once daily, 5 days) was administered intragastrically before the 10-day TMA challenge. AD-like symptoms were assessed by ear thickening, scratching behavior, and pathological or immunofluorescence staining; Cytokines in the skin tissue and serum were measured by cytometric bead array; and the compositions of gut microbiota were assessed by 16S rRNA gene sequencing. AZI pretreatment accelerated the development of ear thickening and enhanced the severity of developed AD-like symptoms. AZI pretreatment promoted the infiltrations of neutrophil-like cells, T cells, and mast cells in ear skin. AZI pretreatment elevated the levels of IL-4, IL-6, and IL-17A in the ear skin of AD model mice, but it increased serum TNF-α and IL-6. AZI-pretreatment increased four gut bacterial genera (Bacteroides, Candidatus_Saccharibacteria_unclassified, Acetatifactor, Firmicutes_unclassified) but depleted three short-chain fatty acids producing gut bacterial genera (Alistipes, Clostridiales_unclassified, Butyricicoccus). AD-associated symptoms were positively associated with skin IL-4 and IL-17A, serum TNF-α, and IL-6, and Acetatifactor, but they negatively correlated to the three decreased gut bacterial genera (Alistipes, Clostridiales_unclassified, Butyricicoccus). Thus, our results demonstrate that AZI exposure deteriorates TMA-induced AD-like symptoms in mice, which is related to the imbalances of gut microbiota and skin/serum cytokines.

Crosstalk Between Circulating Follicular T Helper Cells and Regulatory B Cells in Children With Extrinsic Atopic Dermatitis.

Atopic dermatitis (AD) in early childhood is often the initial manifestation of allergic disease associated with high IgE. Accumulating evidences show that follicular helper T (Tfh) cells play a critical role in promoting B cell differentiation and IgE production, human regulatory B (Breg) cells participate in immunomodulatory processes and inhibition of allergic inflammation. However, the roles and interactions between IL-10-producing Breg cells and Tfh cells in childhood AD are unclear. In this study, we found that the percentage of CD19+IL-10+ Breg cells in children with extrinsic AD was significantly lower than that in age-matched healthy controls, and that it correlated negatively with enhanced CD4+CXCR5+PD-1+ICOS+ circulating Tfh cell responses and increased disease activity; however, there was no significant correlation with serum total IgE levels. A co-culture system revealed that Breg cells from patients with extrinsic AD cannot effectively inhibit differentiation of Tfh cells in an IL-10 dependent manner. Abnormal pSTAT3 signaling induced via Toll-like receptors (TLR), but not the B-cell receptor (BCR) signaling, might contribute to the defect of Breg cells in AD. Taken together, these observations demonstrate an important role for IL-10-producing Breg cells in inhibiting Tfh cell differentiation, and suggest that they may participate in the pathogenesis of AD.

Serum vitamin E levels and chronic inflammatory skin diseases: A systematic review and meta-analysis.

BACKGROUND: Vitamin E has long been linked to skin health, including all of its possible functions in cosmetic products, to its roles in membrane integrity and even the aging process. However, reports on the relationship between serum vitamin E levels and the risk of chronic inflammatory skin diseases have been inconsistent. We performed a systematic review and meta-analysis to evaluate the association between serum vitamin E levels and chronic inflammatory skin diseases. METHODS: We searched the PubMed, Web of Science and Scopus databases, with no time limit up to 30.06.2021. Studies examining serum vitamin E levels in patients with chronic inflammatory skin diseases were selected. RESULTS: Twenty articles met the inclusion criteria. Compared with controls, a lower vitamin E level was found in patients with vitiligo (SMD: -0.70, 95% CI: -1.21 to -0.19), psoriasis (SMD: -2.73, 95% CI: -3.57 to -1.18), atopic dermatitis (SMD: -1.08, 95% CI: -1.80 to -0.36) and acne (SMD: -0.67, 95% CI: -1.05 to -0.30). CONCLUSIONS: Our meta-analysis showed that serum vitamin E levels were lower in patients suffering from vitiligo, psoriasis, atopic dermatitis and acne. This study highlights the need to evaluate vitamin E status to improve its level in patients with skin diseases.

Serum leukocyte cell-derived chemotaxin 2 level is associated with atopic dermatitis patients.

BACKGROUND: Atopic dermatitis (AD) is a chronic skin inflammation with a heterogeneous immunological profile. Leukocyte cell-derived chemotaxin 2 (LECT2) is a liver-derived multifunctional cytokine that has been studied due to its important role in inflammatory and autoimmune diseases. However, the relationship between AD and LECT2 has not been defined. This study was performed to investigate the levels of LECT2 in patients with AD and to determine whether it was associated with the severity and clinical characteristics of AD. METHODS: The study included 42 AD patients and 30 healthy controls from the Affiliated Hospital of Medical School of Ningbo University. Participants' serum levels of LECT2 were measured using enzyme-linked immunosorbent assay kits. The values in the patient group and control group were statistically compared. The relationships between the different markers were evaluated by correlation analysis. RESULTS: The serum levels of LECT2 were significantly higher in AD patients than those in the controls. In addition, LECT2 was significantly correlated with the Scoring of Atopic Dermatitis (SCORAD) index, the level of immunoglobulin E (IgE), and eosinophils (P<0.01, for all 3). CONCLUSIONS: Serum LECT2 levels were evaluated in AD patients. The results showed that LECT2 may be a useful biomarker of AD, and may participate in the occurrence and regulation of inflammation in AD progression.

First clinical expression of equine insect bite hypersensitivity is associated with co-sensitization to multiple Culicoides allergens.

BACKGROUND: Insect bite hypersensitivity (IBH) is an IgE-mediated allergic dermatitis in horses incited by salivary allergens from Culicoides spp. IBH does not occur in Iceland, as the causative agents are absent, however a high prevalence is seen in horses exported to Culicoides-rich environments. AIMS: To study the natural course of sensitization to Culicoides allergens and identify the primary sensitizing allergen(s) in horses exported from Iceland utilizing a comprehensive panel of Culicoides recombinant (r-) allergens. METHOD: IgE microarray profiling to 27 Culicoides r-allergens was conducted on 110 serological samples from horses imported to Switzerland from Iceland that subsequently developed IBH or remained healthy. Furthermore, a longitudinal study of 31 IBH horses determined IgE profiles the summer preceding first clinical signs of IBH (TIBH-1), the summer of first clinical signs (TIBH) and the following summer (TIBH+1). In a group of Icelandic horses residing in Sweden, effects of origin (born in Iceland or Sweden) and duration of IBH (<4 years, 4-7 years, >7 years) on Culicoides-specific IgE was evaluated. Sero-positivity rates and IgE levels were compared. RESULTS: At TIBH, horses were sensitized to a median of 11 r-allergens (range = 0-21), of which nine were major allergens. This was significantly higher than TIBH-1 (3, 0-16), as well as the healthy (1, 0-14) group. There was no significant increase between TIBH and TIBH+1(12, 0-23). IBH-affected horses exported from Iceland had a significantly higher degree of sensitization than those born in Europe, while duration of IBH did not significantly affect degree of sensitization. CONCLUSION: Significant sensitization is only detected in serum the year of first clinical signs of IBH. Horses become sensitized simultaneously to multiple Culicoides r-allergens, indicating that IgE-reactivity is due to co-sensitization rather than cross-reactivity between Culicoides allergens. Nine major first sensitizing r-allergens have been identified, which could be used for preventive allergen immunotherapy.