Complex Autoinflammatory Syndrome Unveils Fundamental Principles of JAK1 Kinase Transcriptional and Biochemical Function.

Autoinflammatory disease can result from monogenic errors of immunity. We describe a patient with early-onset multi-organ immune dysregulation resulting from a mosaic, gain-of-function mutation (S703I) in JAK1, encoding a kinase essential for signaling downstream of >25 cytokines. By custom single-cell RNA sequencing, we examine mosaicism with single-cell resolution. We find that JAK1 transcription was predominantly restricted to a single allele across different cells, introducing the concept of a mutational "transcriptotype" that differs from the genotype. Functionally, the mutation increases JAK1 activity and transactivates partnering JAKs, independent of its catalytic domain. S703I JAK1 is not only hypermorphic for cytokine signaling but also neomorphic, as it enables signaling cascades not canonically mediated by JAK1. Given these results, the patient was treated with tofacitinib, a JAK inhibitor, leading to the rapid resolution of clinical disease. These findings offer a platform for personalized medicine with the concurrent discovery of fundamental biological principles.

Differential Tfh cell phenotypes distinguish IgE-mediated milk allergy from eosinophilic esophagitis in children.

BACKGROUND: IgE-mediated food allergy and eosinophilic esophagitis (EoE) are diseases commonly triggered by milk. Milk-responsive CD4+ T cells producing type 2 cytokines are present in both diseases, yet the clinical manifestation of disease in milk allergy (MA) and EoE are distinct. OBJECTIVE: To identify CD4+ T cell differences between EoE and MA that may be responsible for distinct disease manifestations. METHODS: The total and milk-specific CD4+ T cell phenotype of children with milk allergy (MA), EoE (active or in remission) and controls was measured using spectral flow cytometry of peripheral blood (all groups) or esophageal biopsies (EoE and control). RESULTS: Circulating milk-responsive T cells could be identified in active (A)-EoE and MA. An increased frequency of Th2A cells was also noted in MA and EoE. In circulating T cells, type 2 cytokine production was elevated in MA, but not EoE. Within the milk-responsive Tfh subset, a dichotomy of phenotype was noted: Tfh13 cells predominated in MA, while IL-10-producing Tfh cells predominated in EoE. In the esophagus, CD4+ T cells were constitutively activated and expressed not only type 2 cytokines, but also IL-10 and IL-21 in A-EoE. There was production of IgG4 from CD38+ plasma cells in close proximity to CD4+ T cells. In vitro activation studies demonstrated that IL-10 and IL-21 elicited strong IgG4 responses in B lymphocytes, while IL-4 and IL-13 promoted IgE production. CONCLUSION: Our studies demonstrate a dichotomy of Tfh responses that may be the basis for the different clinical manifestations to milk in EoE and MA.

Untargeted serum metabolomic analysis reveals a role for purinergic signaling in FPIES.

BACKGROUND: Food protein-induced enterocolitis syndrome (FPIES) is a non-IgE-mediated food allergy with a typical onset in infancy. Its symptoms are distinct from those of IgE-mediated food allergies and include severe repetitive vomiting, lethargy, and pallor. FPIES reactions are associated with TH17 cytokines and a systemic innate immune activation; however, the link between immune activation and symptoms is poorly understood. OBJECTIVE: Our aim was to use an untargeted metabolomics approach to identify novel pathways associated with FPIES reactions. METHODS: Serum samples were obtained before, during, and after oral food challenge (OFC) (10 subjects with FPIES and 10 asymptomatic subjects), and they were analyzed by untargeted metabolomics. Two-way ANOVA with false discovery rate adjustment was used for analysis of metabolites. Stomach and duodenal biopsy specimens from non-FPIES donors were stimulated with adenosine in vitro and serotonin measured by immunoassay. RESULTS: The levels of a total of 34 metabolites, including inosine and urate of the purine signaling pathway, were increased during OFCs performed on the patients with symptomatic FPIES compared with the levels found for asymptomatic subjects. Expression of the purine receptors P2RX7 and P2RY10 and the ectonucleotidase CD73 in peripheral blood was significantly reduced after OFC of the patients with FPIES. The level of the serotonin metabolite 5-hydroxyindoleacetate was significantly elevated after reaction. Adenosine stimulation of gastric and duodenal biopsy specimens from FPIES-free donors induced a significant release of serotonin, suggesting a link between purinergic pathway activation and serotonin release. CONCLUSIONS: Activation of the purinergic pathway during FPIES reactions provides a possible mechanism connecting inflammation and vomiting by triggering serotonin release from gastric and duodenal mucosa.

Anti-IgE effect of small-molecule-compound arctigenin on food allergy in association with a distinct transcriptome profile.

BACKGROUND: Excessive production of IgE plays a major role in the pathology of food allergy. In an attempt to identify anti-IgE natural products, Arctium Lappa was one of the most effective herbs among approximately 300 screened medicinal herbs. However, little is known about its anti-IgE compounds. OBJECTIVE: To identify compounds from Arctium Lappa for targeted therapy on IgE production and explore their underlying mechanisms. METHODS: Liquid-liquid extraction and column chromatographic methods were used to purify the compounds. IgE inhibitory effects were determined on IgE-producing human myeloma U266 cells, peanut-allergic murine model and PBMCs from food-allergic patients. Genes involved in IgE inhibition in PBMCs were studied by RNA sequencing. RESULTS: The main compounds isolated were identified as arctiin and arctigenin. Both compounds significantly inhibited IgE production in U266 cells, with arctigenin the most potent (IC50=5.09µg/mL). Arctigenin (at a dose of 13 mg/kg) markedly reduced peanut-specific IgE levels, blocked hypothermia and histamine release in a peanut-allergic mouse model. Arctigenin also significantly reduced IgE production and Th2 cytokines (IL-5, IL-13) by PBMCs. We found 479 differentially expressed genes in PBMCs with arctigenin treatment (p < .001 and fold-change ≥1.5), involving 24 gene ontology terms (p < .001, FDR <0.05); cell division was the most significant. Eleven genes including UBE2C and BCL6 were validated by qPCR. CONCLUSION: Arctigenin markedly inhibited IgE production in U266 cells, peanut-allergic murine model and PBMCs from allergic patients by down-regulating cell division, cell cycle-related genes and up-regulating anti-inflammatory factors.

Mapping Sequential IgE-Binding Epitopes on Major and Minor Egg Allergens.

INTRODUCTION: Molecular studies of hen's egg allergens help define allergic phenotypes, with IgE to sequential (linear) epitopes on the ovomucoid (OVM) protein associated with a persistent disease. Epitope profiles of other egg allergens are largely unknown. The objective of this study was to construct an epitope library spanning across 7 allergens and further evaluate sequential epitope-specific (ses-)IgE and ses-IgG4 among baked-egg reactive or tolerant children. METHODS: A Bead-Based Epitope Assay was used to identify informative IgE epitopes from 15-mer overlapping peptides covering the entire OVM and ovalbumin (OVA) proteins in 38 egg allergic children. An amalgamation of 12 B-cell epitope prediction tools was developed using experimentally identified epitopes. This ensemble was used to predict epitopes from ovotransferrin, lysozyme, serum albumin, vitellogenin-II fragment, and vitellogenin-1 precursor. Ses-IgE and ses-IgG4 repertoires of 135 egg allergic children (82 reactive to baked-egg, the remaining 52 tolerant), 46 atopic controls, and 11 healthy subjects were compared. RESULTS: 183 peptides from OVM and OVA were screened and used to create an aggregate algorithm, improving predictions of 12 individual tools. A final library of 65 sequential epitopes from 7 proteins was constructed. Egg allergic children had higher ses-IgE and lower ses-IgG4 to predominantly OVM epitopes than both atopic and healthy controls. Baked-egg reactive children had similar ses-IgG4 but greater ses-IgE than tolerant group. A combination of OVA-sIgE with ses-IgEs to OVM-023 and OVA-028 was the best predictor of reactive phenotype. CONCLUSION: We have created a comprehensive epitope library and showed that ses-IgE is a potential biomarker of baked-egg reactivity.

Tumor Necrosis Factor Inhibitor-Induced Psoriasis in a Pediatric Crohn's Disease Patient Successfully Treated with Ustekinumab.

BACKGROUND: Tumor necrosis factor (TNF) inhibitors are widely used in pediatric patients with inflammatory bowel disease, as well as psoriasis. However, there is growing evidence that these medications can also paradoxically induce a psoriasiform skin reaction in a subset of patients. GOALS: We seek to share our experience in treating severe TNF inhibitor-induced psoriasis in a pediatric patient with Crohn’s disease. STUDY: We report a case of a 10-year-old female with Crohn’s disease, who developed psoriasis after twelve months of infliximab therapy. Her skin disease was recalcitrant to topical therapies, methotrexate, and phototherapy. RESULTS: The patient was transitioned to ustekinumab with significant improvement in her symptoms and maintenance of remission of her bowel disease. CONCLUSION: This is the first reported case of a school-age pediatric patient with TNF inhibitor-induced psoriasis treated with ustekinumab. Controlled trials are warranted to fully assess the safety and efficacy of ustekinumab for treating TNF inhibitor-induced psoriasis in the pediatric population.J Drugs Dermatol. 2020;19(3): doi:10.36849/JDD.2020.2106.

Real World Experience With Ustekinumab in Children and Young Adults at a Tertiary Care Pediatric Inflammatory Bowel Disease Center.

BACKGROUND: Ustekinumab is an effective therapy for Crohn disease currently approved for adults. Off-label use in the pediatric population is increasing, but its effectiveness in this age group has not been reported. AIMS: The aim of the study was to describe real-world experience with ustekinumab at a tertiary care pediatric inflammatory bowel disease (IBD) center. METHODS: As part of an ongoing observational cohort study of biologic-treated pediatric IBD patients initiated in October 2014, data on demographics, disease behavior, location and activity, treatment, and surgical history were collected for all patients receiving ustekinumab. Disease activity was assessed using the Harvey Bradshaw index or partial Mayo score. Primary outcome was steroid-free remission at 52 weeks. Descriptive statistics summarized the safety and efficacy outcomes, and univariate analyses were performed to examine associations of clinical characteristics with efficacy. RESULTS: Fifty-two children and young adults initiating ustekinumab were analyzed; 81% Crohn Disease, 8% ulcerative colitis, and 11% IBD-unspecified. Median [IQR] age at induction was 16.8 [14-18] years. Patients were followed for a minimum of 12 months. Most patients (81%) failed >1 anti-TNF, and 37% failed anti-TNF and vedolizumab; 10 patients were biologic-naïve. At week 52, 75% were still on ustekinumab, and 50% (bio-exposed) and 90% (bio-naïve) were in steroid-free remission. Two infusion reactions and neither serious adverse events nor serious infections were observed. CONCLUSIONS: Our results suggest that ustekinumab is efficacious and safe in pediatric patients with IBD. Controlled clinical trial data are needed to confirm these observations.

De Novo Crohn's Disease of the Pouch in Children Undergoing Ileal Pouch-Anal Anastomosis for Ulcerative Colitis.

BACKGROUND: Approximately 10% of children with ulcerative colitis (UC) undergo colectomy with ileal pouch-anal anastomosis (IPAA). We aimed to describe the postoperative outcomes, with an emphasis on chronic pouch inflammation including de novo Crohn disease (CD) at a tertiary care inflammatory bowel disease center. METHODS: Electronic medical records of all children who underwent colectomy ≤18 years between 2008 and 2017 were reviewed. Clinical and laboratory data were recorded. Primary outcome was frequency of chronic pouch inflammation including de novo CD. Secondary outcomes included early (≤30 days from index surgery) and late postoperative complications. Descriptive statistics (median and interquartile range) summarized the data and univariate analysis tested associations with outcomes. RESULTS: Fifty-eight children underwent colectomy and 56 completed IPAA. Median age at diagnosis was 14 years (12-16.2) and at colectomy 16.2 years (14.2-17.7) with median follow-up of 13 months (5-43). Sixty-six percent underwent 3-stage IPAA and 78% were biologic exposed. Eleven had chronic pouchitis, 73% antibiotic refractory and 25% met criteria for de novo CD by median of 19 months (9-41). A total of 21% and 50% experienced early and late surgical complications, most commonly ileus and recurrent IPAA stricture. The pouch failure rate was 3.6%. Chronic pouch inflammation was associated with a later diagnosis of de novo CD (P = 0.0025). CONCLUSIONS: In pediatric UC, CD is not uncommon after IPAA. Chronic pouch inflammation often precedes a diagnosis of de novo CD. Families should be informed of the short- and long-term outcomes in children before UC surgery.

EBV Status and Thiopurine Use in Pediatric IBD.

OBJECTIVES: Epstein Barr virus (EBV) is a human herpes virus that infects 90% of the world's population and has been linked to the development of lymphoproliferative disorders (LPDs) and immunosuppression. Primary EBV infection in patients with IBD on thiopurines is a risk factor for LPD, including lymphoma. We aimed to describe EBV status in a pediatric population with IBD with an emphasis on those initiating thiopurines. METHODS: Electronic medical records and EBV serologies were reviewed and categorized into asymptomatic screening versus suspicion for acute infection. EBV status before therapy was described by sex, age, and therapeutic regimen. Descriptive statistics and univariate analysis were employed. RESULTS: Only 150 (22%) of our 688 pediatric patients with IBD had documented EBV status regardless of age or treatment regimen. Only 17% were assessed for suspicion of acute infection and 83% for screening. Sixty-four (52%) screened patients were checked before starting any treatment and only 40% were immunoglobulin (Ig)G positive. There was no difference in mean age between the seronegative and seropositive group. The majority (63%) of thiopurine-treated patients were IgG negative before starting therapy. Eighty percent of primary EBV infections occurred on thiopurines at a mean (SD) of 2 ±â€Š1.5 years after initiating therapy. CONCLUSIONS: The majority of our pediatric patients with IBD with documented EBV status were IgG negative at thiopurine initiation. Thiopurines were also associated with primary EBV infection. EBV status may be an important determinate of whether physicians prescribe thiopurines given the risk of primary EBV infections and lymphoproliferative diseases.

Effect of Antiasthma Simplified Herbal Medicine Intervention on neutrophil predominant airway inflammation in a ragweed sensitized murine asthma model.

BACKGROUND: Neutrophil-predominant asthma is less responsive to steroids and associated with poorer disease control. The effects of Antiasthma Simplified Herbal Medicine Intervention (ASHMI), a traditional Chinese medicine formula reported to be efficacious in asthmatic patients and murine asthma models, on neutrophil predominant asthma are unknown. OBJECTIVE: To determine the effects of standard ASHMI and refined formula ASHMI (ASHMI(II)) in a neutrophil-predominant murine model of ragweed (RW) asthma and explore underlying mechanisms. METHODS: BALB/c mice were systemically sensitized, intranasally challenged with RW extract, and orally treated with ASHMI, ASHMI(II), or vehicle (water). In a separate experiment, some RW sensitized mice were treated with dexamethasone before challenge. After RW challenge, airway hyperreactivity (AHR), total and differential bronchoalveolar lavage fluid leukocyte counts, lung histologic features, and bronchoalveolar lavage fluid cytokine and chemokine levels were assessed. RW stimulation of the murine macrophage cell line RAW264.7 was used to determine effects of ASHMI active compound ganoderic acid C1 (GAC1) on tumor necrosis factor α (TNF-α) production and regulation of phosphorylated IκB and histone deacetylase 2 (HDAC2) levels. RESULTS: ASHMI and ASHMI(II) markedly reduced AHR, mucous production, neutrophilic inflammation, and TNF-α, interleukin 8, and interleukin 17 levels and decreased eosinophilic inflammation and TH2 responses in vivo (P < .01-.001 for all). GAC1 inhibited TNF-α production in RW-stimulated RAW264.7 cells in association with suppression of phosphorylated IκB and increased HDAC2 expression. Dexamethasone failed to reduce AHR and neutrophilic inflammation. CONCLUSION: ASHMI treatment was efficacious in a murine model of neutrophil-predominant asthma via modulation of innate chemokines, TH2 responses, nuclear factor-κB, and HDAC2. ASHMI, and/or its constituent GAC1, may be a valuable option for treating neutrophil-predominant asthma.

Immune cell therapy in IBD.

The therapeutic landscape of IBD has undergone a dramatic transformation since the advent of biologic therapies, especially TNF inhibitors. However, 30% of patients are primary nonresponders to biologic therapy and secondary failures are frequent. Due to substantial progress in our understanding of the biology of regulatory T cells (Tregs) and in the pathways of homing to the gastrointestinal tract, novel cell-based therapies for IBD have become possible. For example, although a reductionist view, one could envisage IBD as an imbalance between the proinflammatory effectors (such as Th17 cells) and the anti-inflammatory regulators (like Tregs). Here we focus on the development of ex vivo and in vivo approaches to enhance Tregs in the gastrointestinal tract. Specifically, herein we highlight a recently concluded phase 1/2a clinical trial that investigated the safety and efficacy of a single injection of escalating doses of autologous ovalbumin-specific Tregs in patients with active Crohn's disease refractory to conventional therapy. This therapy was well tolerated and demonstrated dose-related efficacy. We also discuss the potential of directing Tregs derived through intranasal as well as epicutaneous immunization to the gastrointestinal tract by enhancing their gut homing signature and their potential to decrease gastrointestinal inflammation. Finally, the strengths and pitfalls of these new therapeutic approaches are discussed as we move forward in this largely uncharted territory.

Complementary and alternative medicine use at a single pediatric inflammatory bowel disease center.

The aim of this study was to determine the use of complementary and alternative medicine (CAM) in an inflammatory bowel disease population at a single pediatric center. The secondary aims were to determine predictors of CAM use and assess parental attitude to CAM use. A survey was developed that was distributed electronically and given out in the clinic. Two hundred thirty-five surveys were analyzed. Thirty-six percent of respondents reported that their children had used CAM, while 19.6% were current users. Sixty-three percent of respondents were "extremely" or "very supportive" of CAM and 57.6% would have been "extremely" or "very supportive" at the time of their children's diagnosis. The most commonly used CAM modalities were fish oil (48.8%), probiotics (22.5%), acupuncture/pressure (17.5%), aloe (16.3%), yoga/meditation (16.3%), chiropractic (12%), and herbal medicine (13.8%). Multivariate analysis revealed 2 independent factors predictive of subjects using CAM: use of biologics (odds ratio of 2.8; p = .008) and subjects' parent using CAM (odds ratio of 10.9; p ≤ .001). More than one third of children in this study and their parents have used CAM. Families are supportive of CAM both at the time of diagnosis and as an ongoing component of their child's treatment even if they were not past or current users of CAM. Predictors of CAM use were treatment with a biologic and having a parent who used CAM.

Single-center Experience With Upadacitinib for Adolescents With Refractory Inflammatory Bowel Disease.

BACKGROUND: Upadacitinib (UPA) is a novel selective JAK inhibitor approved for adults with ulcerative colitis (UC) and with positive phase 3 data for Crohn's disease (CD). Pediatric off-label use is common due to delays in pediatric approvals; real-world data on UPA are needed to understand the safety and effectiveness in pediatric IBD. METHODS: This is a single-center retrospective case series study of adolescents (12-17 years) with inflammatory bowel disease IBD on UPA. The primary outcome was postinduction steroid-free clinical remission (SF-CR) defined as Pediatric UC Activity Index (PUCAI) or Pediatric CD Activity Index (PCDAI) ≤10. Secondary outcomes include postinduction clinical response (decrease ≥12.5 in PUCAI/PCDAI), postinduction C-reactive protein (CRP) normalization, 6-month SF-CR, and intestinal ultrasound response and remission. Adverse events were recorded through last follow-up. RESULTS: Twenty patients (9 CD, 10 UC, 1 IBD-U; 55% female; median age 15 years, 90% ≥2 biologics) were treated with UPA for ≥12 weeks (median 51 [43-63] weeks). Upadacitinib was used as monotherapy in 55% and as combination with ustekinumab and vedolizumab in 35% and 10%, respectively. Week 12 SF-CR was achieved in 75% (15/20) and 80% (16/20) with CRP normalization. About 3/4 (14/19) achieved SF-CR at 6 months. Adverse event occurred in 2 patients (10%): Cytomegalovirus colitis requiring hospitalization and hyperlipidemia requiring no treatment. In the 75% with ultrasound monitoring, response and remission were achieved in 77% and 60%, respectively. CONCLUSION: While awaiting pediatric registration trials, our data suggest that UPA is effective in inducing and maintaining SF-CR in adolescents with highly-refractory IBD with an acceptable safety profile.

This case series presents novel data on the effectiveness and safety of upadacitinib in adolescent patients with IBD.

Cytomegalovirus Colitis in a Patient with Severe Treatment Refractory Ulcerative Colitis.

Background: Cytomegalovirus (CMV) can be reactivated in ulcerative colitis (UC), but its role in progression of inflammation is unclear. Risk factors include severe colitis and treatment with immunosuppressive medications, particularly corticosteroids and immunomodulators. Methods: We report a case of cytomegalovirus colitis in a pediatric patient with pancolitis who had been refractory to aminosalicylate, infliximab, and ustekinumab and was in clinical remission and with transmural response on upadacitinib. Results: This is a case of a 13-year-old male with UC refractory to multiple therapies who were in clinical remission on upadacitinib 30 mg daily. He developed an acute increase in symptoms and did not respond to therapy escalation with increased upadacitinib 45 mg daily for 2 weeks and prednisone for 1 week. He was diagnosed with cytomegalovirus colitis on flexible sigmoidoscopy biopsy. He was treated with intravenous ganciclovir with tapering of immunosuppressive regimen. Despite initial response, he underwent subtotal colectomy and subsequent restorative proctocolectomy with ileal pouch anal-anastomosis. Conclusions: Despite our patient having multiple risk factors for developing CMV colitis, upadacitinib may have played a role when considering its known impact on the herpes family of viruses. CMV colitis should be evaluated for in any patient who presents with worsening symptoms without evidence of other infection or response to increase in therapy.

Epicutaneous Immunotherapy with CBir1 Alleviates Intestinal Inflammation.

BACKGROUND: Inflammatory bowel disease may be due to failed tolerance to normal gut bacteria. We demonstrate that epicutaneous immunotherapy (ET) to ovalbumin can alleviate colitis in murine models. However, most people are tolerant to or have anergy to ovalbumin. Half of Crohn's disease (CD) patients have CBir1 antibodies that can be elevated years before CD development. We determined whether ET with a CBir1 multi-epitope peptide (MEP1) could alleviate colitis. METHODS: Wild type mice (C57BL/6) were transferred with CBir1 T cell receptor (TCR) T cells followed by epicutaneous application of MEP1. Proliferating Foxp3+ T cells were measured in mesenteric lymph nodes (LNs), spleen, small intestine, and colon by flow cytometry. Lymphocytes from MEP1 epicutaneously exposed and immunized C57BL/6 mice were cultured with MEP1. Interferon (IFN)-γ production was measured. Colitis was induced by transferring CD4+CD45Rbhi T cells from CBIR1 TCR or C57BL/6 mice into RAG1-/- mice. Mice were treated with ET. Body weight, colon length, colonic cytokine production, histological inflammation, inflammatory genes, and regulatory T cells (Tregs) from lamina propria were measured. RESULTS: ET with 10 µg of MEP1 induced CBir1-specific Tregs that migrated to the small intestine and colon and suppressed MEP1-specific IFN-γ production. ET alleviated colitis when the model utilized CBir1 TCR T cells in mice colonized with CBir1 or A4Fla2 positive bacteria. Treated mice had improved colon length and histological inflammation and reduced colonic IFN-γ production. CONCLUSION: Epicutaneous immunotherapy with MEP1 induced Tregs that migrate to intestines and suppress inflammation in mice with CBir1 or A4Fla2-positive bacterial colonization. This could be a potential strategy to treat CD and warrants further study.

Epicutaneous immunotherapy with a CBir1 multi-epitope peptide, the dominant flagellin for both murine and human, can induce Tregs that migrate to intestines and suppress inflammation in mice with CBir1 or A4Fla2-positive bacterial colonization.

Inhibition of pathologic immunoglobulin E in food allergy by EBF-2 and active compound berberine associated with immunometabolism regulation.

Introduction: Food allergy is a significant public health problem with limited treatment options. As Food Allergy Herbal Formula 2 (FAHF-2) showed potential as a food allergy treatment, we further developed a purified version named EBF-2 and identified active compounds. We investigated the mechanisms of EBF-2 on IgE-mediated peanut (PN) allergy and its active compound, berberine, on IgE production. Methods: IgE plasma cell line U266 cells were cultured with EBF-2 and FAHF-2, and their effects on IgE production were compared. EBF-2 was evaluated in a murine PN allergy model for its effect on PN-specific IgE production, number of IgE+ plasma cells, and PN anaphylaxis. Effects of berberine on IgE production, the expression of transcription factors, and mitochondrial glucose metabolism in U266 cells were evaluated. Results: EBF-2 dose-dependently suppressed IgE production and was over 16 times more potent than FAHF-2 in IgE suppression in U266 cells. EBF-2 significantly suppressed PN-specific IgE production (70%, p<0.001) and the number of IgE-producing plasma cells in PN allergic mice, accompanied by 100% inhibition of PN-induced anaphylaxis and plasma histamine release (p<0.001) without affecting IgG1 or IgG2a production. Berberine markedly suppressed IgE production, which was associated with suppression of XBP1, BLIMP1, and STAT6 transcription factors and a reduced rate of mitochondrial oxidation in an IgE-producing plasma cell line. Conclusions: EBF-2 and its active compound berberine are potent IgE suppressors, associated with cellular regulation of immunometabolism on IgE plasma cells, and may be a potential therapy for IgE-mediated food allergy and other allergic disorders.

Allergic sensitization can be induced via multiple physiologic routes in an adjuvant-dependent manner.

BACKGROUND: Oral exposure to food allergens may be limited in infancy, and the initial site of antigen exposure likely plays an important role in food allergy induction. OBJECTIVE: To examine the impact of different routes of exposure by using milk allergens, with and without adjuvant, on sensitization. METHODS: C3H/HeJ mice were repeatedly exposed to the milk allergen α-lactalbumin (ALA), with or without cholera toxin (CT). Sensitization routes used were intragastric, cutaneous, intranasal, and sublingual. Anaphylaxis severity was assessed by symptoms and body temperature in response to oral challenge. Antigen-specific serum antibodies were measured by ELISA. The mechanism of adjuvant activity of cutaneous CT was also determined. RESULTS: Sensitization to ALA as measured by allergen-specific IgE occurred by all routes of sensitization and was maximal in response to cutaneous exposure. Sensitization was dependent on CT and did not occur to antigen alone by any route. Mucosal, but not cutaneous, exposure resulted in a robust allergen-specific IgA response. Anaphylaxis occurred in all sensitized groups when orally challenged with ALA. Topical CT induced migration of langerin(neg) dermal dendritic cells to the lymph node, resulting in enhanced proliferation and T(H)2 cytokine production from responder T cells. CONCLUSIONS: Sensitization can occur via all physiologic routes when adjuvant is present. The skin is a potent and likely important physiologic route of sensitization whereby adjuvant induces an efflux of antigen-bearing dermal dendritic cells to the lymph node that generate a proallergic T(H)2 response.

Induction of Severe Eosinophilic Esophagitis and Multi-Organ Inflammation by Airborne Allergens is Associated with IL-4/IL-13 and CCL11 but Not IgE in Genetic Susceptible Mice.

Background: Eosinophilic Esophagitis (EoE) is an increasingly common chronic inflammatory disease. The pathological mechanisms underlying EoE are largely unknown. Objective: We sought to understand the mechanisms underlying aeroallergen-induced EoE in Sharpin gene deficient (Sharpin-/-) mice that is prone to inflammatory response. Methods: Sharpin-/-mice were exposed with Aspergillus fumigatus and ovalbumin intranasally every alternate day for 4 weeks. Wild type (WT) naïve mice, WT exposed, and un-exposed Sharpin-/- mice were controls. Histopathological analysis was performed by H&E, trichrome and major basic protein staining. Total and specific IgE, IgG, and IgA levels were measured by ELISA and Th2 cytokine and CCL11 chemokine gene expression were determined. Results: Airborne allergen exposed Sharpin-/- mice showed severe eosinophilic inflammation in the esophagus (p < 0.001), and markedly increased epithelial thickening (p < 0.0001) compared to WT normal controls, whereas airborne allergen exposed WT mice and unexposed Sharpin-/- mice only showed mild eosinophilic inflammation in the esophagus. These exposed Sharpin-/- mice also showed over 7-fold increase in blood eosinophils (p < 0.0001), 60-fold increase in eosinophils in bronchoalveolar lavage fluid (p < 0.0001) and 4-fold increase in eosinophils in the skin (p < 0.0001) compared to normal controls. Surprisingly, exposed Sharpin-/- mice did not show elevation of serum total or antigen-specific IgE levels but reduced total IgA and IgG levels than normal controls There was a marked increase in IL-4, IL-13 and CCL11 gene expression in esophageal tissue (p < 0.001) in exposed Sharpin-/- mice compared to WT normal mice. Conclusion: Th2 cytokines and chemokines, but not IgE may play an important pathologic role in aeroallergen-induced EoE. This study may provide insight into new therapeutics for EoE.

Outcomes of Children with Inflammatory Bowel Disease who Develop Anti-tumour Necrosis Factor-induced Skin Reactions.

BACKGROUND AND AIMS: Anti-tumour necrosis factor [anti-TNF] induced skin reactions are common adverse events in paediatric inflammatory bowel disease [IBD]. We aimed to report on outcomes of children with anti-TNF induced skin reactions who switched to ustekinumab [UST] vs. continued anti-TNF therapy. METHODS: Charts were reviewed for paediatric IBD patients with anti-TNF induced skin reactions. Skin reactions, including psoriasiform dermatitis [PD], were classified as mild or severe based on a severity score. Primary outcome was frequency of skin resolution at 6 months. Secondary outcomes were combined clinical remission and skin resolution at 6 months and skin resolution at latest follow-up. RESULTS: A total of 111/638 [17%] children ([85, 21%] infliximab [IFX]; [26, 11%] adalimumab [ADA]) developed skin reactions. Eighty [72%] had PD, 25 [23%] infections, and four [4%] alopecia areata; 71 [64%] continued anti-TNF; and 40 [36%] switched to UST. In all, 73 [66%] had severe reactions and were more likely to switch to UST than if mild (37 [51%] vs. 3 [8%]; p <0.0001). Switching to UST had a higher rate and odds of resolution (29 [73%] vs. 24 [34%]; p <0.0001; odds ratio [OR] = 19.7, 95% confidence interval [CI]: 5.6, 69.5; p <0.0001) and combined remission (21 [52%] vs. 22 [31%]; p = 0.03; OR = 8.5, 95% CI: 2.5, 28.4; p = 0.0005] vs. continuing anti-TNF at 6 months. CONCLUSIONS: Children who switched to UST after anti-TNF induced skin reactions were more likely to have improved outcomes than those who continued anti-TNF therapy. Future studies are needed to determine immune mechanisms of anti-TNF induced skin reactions and treatment response.