Tissue-specific inducible IL-33 expression elicits features of eosinophilic esophagitis.

BACKGROUND: IL-33 is a type 2 inflammatory cytokine that is elevated in the esophageal epithelium of eosinophilic esophagitis (EoE) subjects. We previously developed a mouse model of EoE dependent on constitutive overexpression of IL-33 from the esophageal epithelium (EoE33). OBJECTIVE: Our objective was to develop an inducible, IL-33-dependent model of EoE and examine induction of EoE-associated pathology. METHODS: We utilized a tetracycline-inducible system to express IL-33 in the esophagus by generating 2 transgenic mice. The first (iSophagus) expresses a reverse tetracycline transactivator from the esophageal epithelium. The second (TRE33) features a tetracycline response element driving expression of IL-33. When crossed, these mice generate an inducible model of EoE (iEoE33). Mice were administered doxycycline-infused chow for up to 2 weeks. Cytokines were assessed by ELISA or bead-based multiplex analysis. T cells were assessed by flow cytometry. Pathology was assessed by histology and immunohistochemistry for IL-33, eosinophil peroxidase, CD4, and Ki-67. iEoE33 was treated with steroids and crossed with IL-13-/- mice. RESULTS: Doxycycline-treated iEoE33 mice demonstrated expression of IL-33 in the esophageal epithelium, and esophageal pathology including eosinophilia, CD4+ cell infiltrate, basal zone hyperplasia, and dilated intercellular spaces. These findings became pronounced on day 7 of induction, were accompanied by weight loss and esophageal thickening, and were steroid responsive and IL-13 dependent. CONCLUSION: Inducible IL-33 expression in the esophageal epithelium elicited features pathognomonic of EoE. iEoE33 enables investigation of EoE disease mechanisms as well as initiation, progression, and resolution.

Advances and ongoing challenges in eosinophilic gastrointestinal disorders presented at the CEGIR/TIGERs Symposium at the 2024 American Academy of Allergy, Asthma & Immunology meeting.

The Consortium of Eosinophilic Gastrointestinal disease Researchers (CEGIR) and The International Gastrointestinal Eosinophil Researchers (TIGERs) organized a daylong symposium at the 2024 annual meeting of the American Academy of Allergy, Asthma & Immunology. The symposium featured new discoveries in basic and translational research as well as debates on the mechanisms and management of eosinophilic gastrointestinal diseases. Updates on recent clinical trials and consensus guidelines were also presented. We summarize the updates on eosinophilic gastrointestinal diseases presented at the symposium.

Identification of cellular retinoic acid binding protein 2 (CRABP2) as downstream target of nuclear factor I/X (NFIX): implications for skeletal dysplasia syndromes.

Nuclear factor I/X (NFIX) mutations are associated with 2 skeletal dysplasias, Marshall-Smith (MSS) and Malan (MAL) syndromes. NFIX encodes a transcription factor that regulates expression of genes, including Bobby sox (BBX) and glial fibrillary acidic protein (GFAP) in neural progenitor cells and astrocytes, respectively. To elucidate the role of NFIX mutations in MSS, we studied their effects in fibroblast cell lines obtained from 5 MSS unrelated patients and 3 unaffected individuals. The 5 MSS NFIX frameshift mutations in exons 6-8 comprised 3 deletions (c.819-732_1079-948del, c.819-471_1079-687del, c.819-592_1079-808del), an insertion (c.1037_1038insT), and a duplication (c.1090dupG). Quantitative reverse transcription polymerase chain reaction (qRT-PCR) and western blot analyses using MSS and unrelated control fibroblasts and in vitro expression studies in monkey kidney fibroblast (COS-7) cells showed that frameshift mutations in NFIX exons 6-8 generated mutant transcripts that were not cleared by nonsense-mediated-decay mechanisms and encoded truncated NFIX proteins. Moreover, BBX or GFAP expression was unaffected in the majority of MSS fibroblasts. To identify novel NFIX downstream target genes, RNA sequencing and proteomics analyses were performed on mouse embryonic fibroblast (MEF) cells derived from control Nfix+/+, Nfix+/Del2, Nfix+/Del24, NfixDel24/Del24, Nfix+/Del140, and NfixDel140/Del140 mice, compared with NfixDel2/Del2 mice which had developmental, skeletal, and neural abnormalities. This identified 191 transcripts and 815 proteins misregulated in NfixDel2/Del2 MEFs with ≥2-fold-change (P <0 .05). Validation studies using qRT-PCR and western blot analyses confirmed that 2 genes, cellular retinoic acid binding protein 2 (Crabp2) and vascular cell adhesion molecule 1 (Vcam1), were misregulated at the RNA and protein levels in NfixDel2/Del2 MEFs, and that CRABP2 and VCAM1 expressions were altered in 60%-100% of MSS fibroblast cells. Furthermore, in vitro luciferase reporter assays confirmed that NFIX directly regulates CRABP2 promoter activity. Thus, these altered genes and pathways may represent possible targets for drugs as potential treatments and therapies for MSS.

Ly6Chi Monocytes Are Metabolically Reprogrammed in the Blood during Inflammatory Stimulation and Require Intact OxPhos for Chemotaxis and Monocyte to Macrophage Differentiation.

Acute inflammation is a rapid and dynamic process involving the recruitment and activation of multiple cell types in a coordinated and precise manner. Here, we investigate the origin and transcriptional reprogramming of monocytes using a model of acute inflammation, zymosan-induced peritonitis. Monocyte trafficking and adoptive transfer experiments confirmed that monocytes undergo rapid phenotypic change as they exit the blood and give rise to monocyte-derived macrophages that persist during the resolution of inflammation. Single-cell transcriptomics revealed significant heterogeneity within the surface marker-defined CD11b+Ly6G-Ly6Chi monocyte populations within the blood and at the site of inflammation. We show that two major transcriptional reprogramming events occur during the initial six hours of Ly6Chi monocyte mobilisation, one in the blood priming monocytes for migration and a second at the site of inflammation. Pathway analysis revealed an important role for oxidative phosphorylation (OxPhos) during both these reprogramming events. Experimentally, we demonstrate that OxPhos via the intact mitochondrial electron transport chain is essential for murine and human monocyte chemotaxis. Moreover, OxPhos is needed for monocyte-to-macrophage differentiation and macrophage M(IL-4) polarisation. These new findings from transcriptional profiling open up the possibility that shifting monocyte metabolic capacity towards OxPhos could facilitate enhanced macrophage M2-like polarisation to aid inflammation resolution and tissue repair.

Challenging assumptions about the demographics of eosinophilic gastrointestinal diseases: A systematic review.

Background: The demographic characteristics of patients with eosinophilic gastrointestinal diseases (EGIDs) are poorly understood. Population-based assessments of EGID demographics may indicate health disparities in diagnosis. Objectives: We aimed to characterize the demographic distribution of EGIDs and evaluate the potential for bias in reporting patient characteristics. Methods: We conducted a systematic review, extracting data on age, sex, gender, race, ethnicity, body mass index, insurance, and urban/rural residence on EGID patients and the source population. Differences in proportions were assessed by chi-square tests. Demographic reporting was compared to recent guidelines. Results: Among 50 studies that met inclusion/exclusion criteria, 12 reported ≥1 demographic feature in both EGID and source populations. Except for age and sex or gender, demographics were rarely described (race = 4, ethnicity = 1, insurance = 1) or were not described (body mass index, urban/rural residence). A higher proportion of male subjects was observed for EoE or esophageal eosinophilia relative to the source population, but no difference in gender or sex distribution was observed for other EGIDs. "Sex" and "gender" were used interchangeably, and frequently only the male proportion was reported. Reporting of race and ethnicity was inconsistent with guidelines. Conclusion: Current data support a male predominance for EoE only. Evidence was insufficient to support enrichment of EGIDs in any particular racial, ethnic, or other demographic group. Population-based studies presenting demographics on both cases and source populations are needed. Implementation of guidelines for more inclusive reporting of demographic characteristics is crucial to prevent disparities in timely diagnosis and management of patients with EGIDs.

The Relationship Between Eosinophilic Esophagitis and Immunotherapy.

Immunotherapy is a treatment approach based on the principle of incremental allergen exposure to achieve desensitization. Recently, oral immunotherapy has been introduced as a treatment of IgE-mediated food allergy. Some patients receiving oral immunotherapy for food allergy may develop eosinophilic esophagitis. Here, we summarize the literature examining this association, its treatment, and outcomes and discuss possible explanations for this clinical phenomenon. We further identify potential associations with aeroallergen sensitivity and other forms of immunotherapy including subcutaneous immunotherapy and sublingual immunotherapy. Finally, we discuss management of immunotherapy-induced eosinophilic esophagitis. Epicutaneous immunotherapy is highlighted as an area of therapeutic investigation.

Is ChatGPT a trusted source of information for total hip and knee arthroplasty patients?

Aims: While internet search engines have been the primary information source for patients' questions, artificial intelligence large language models like ChatGPT are trending towards becoming the new primary source. The purpose of this study was to determine if ChatGPT can answer patient questions about total hip (THA) and knee arthroplasty (TKA) with consistent accuracy, comprehensiveness, and easy readability. Methods: We posed the 20 most Google-searched questions about THA and TKA, plus ten additional postoperative questions, to ChatGPT. Each question was asked twice to evaluate for consistency in quality. Following each response, we responded with, "Please explain so it is easier to understand," to evaluate ChatGPT's ability to reduce response reading grade level, measured as Flesch-Kincaid Grade Level (FKGL). Five resident physicians rated the 120 responses on 1 to 5 accuracy and comprehensiveness scales. Additionally, they answered a "yes" or "no" question regarding acceptability. Mean scores were calculated for each question, and responses were deemed acceptable if ≥ four raters answered "yes." Results: The mean accuracy and comprehensiveness scores were 4.26 (95% confidence interval (CI) 4.19 to 4.33) and 3.79 (95% CI 3.69 to 3.89), respectively. Out of all the responses, 59.2% (71/120; 95% CI 50.0% to 67.7%) were acceptable. ChatGPT was consistent when asked the same question twice, giving no significant difference in accuracy (t = 0.821; p = 0.415), comprehensiveness (t = 1.387; p = 0.171), acceptability (χ2 = 1.832; p = 0.176), and FKGL (t = 0.264; p = 0.793). There was a significantly lower FKGL (t = 2.204; p = 0.029) for easier responses (11.14; 95% CI 10.57 to 11.71) than original responses (12.15; 95% CI 11.45 to 12.85). Conclusion: ChatGPT answered THA and TKA patient questions with accuracy comparable to previous reports of websites, with adequate comprehensiveness, but with limited acceptability as the sole information source. ChatGPT has potential for answering patient questions about THA and TKA, but needs improvement.

Epithelial overexpression of IL-33 induces eosinophilic esophagitis dependent on IL-13.

BACKGROUND: Eosinophilic esophagitis (EoE) is an increasingly common inflammatory condition of the esophagus; however, the underlying immunologic mechanisms remain poorly understood. The epithelium-derived cytokine IL-33 is associated with type 2 immune responses and elevated in esophageal biopsy specimens from patients with EoE. OBJECTIVE: We hypothesized that overexpression of IL-33 by the esophageal epithelium would promote the immunopathology of EoE. METHODS: We evaluated the functional consequences of esophageal epithelial overexpression of a secreted and active form of IL-33 in a novel transgenic mouse, EoE33. EoE33 mice were analyzed for clinical and immunologic phenotypes. Esophageal contractility was assessed. Epithelial cytokine responses were analyzed in three-dimensional organoids. EoE33 phenotypes were further characterized in ST2-/-, eosinophil-deficient, and IL-13-/- mice. Finally, EoE33 mice were treated with dexamethasone. RESULTS: EoE33 mice displayed ST2-dependent, EoE-like pathology and failed to thrive. Esophageal tissue remodeling and inflammation included basal zone hyperplasia, eosinophilia, mast cells, and TH2 cells. Marked increases in levels of type 2 cytokines, including IL-13, and molecules associated with immune responses and tissue remodeling were observed. Esophageal organoids suggested reactive epithelial changes. Genetic deletion of IL-13 in EoE33 mice abrogated pathologic changes in vivo. EoE33 mice were responsive to steroids. CONCLUSIONS: IL-33 overexpression by the esophageal epithelium generated immunopathology and clinical phenotypes resembling human EoE. IL-33 may play a pivotal role in the etiology of EoE by activating the IL-13 pathway. EoE33 mice are a robust experimental platform for mechanistic investigation and translational discovery.

Mononuclear cell composition and activation in blood and mucosal tissue of eosinophilic esophagitis.

Introduction: Eosinophilic esophagitis (EoE) is a chronic, inflammatory, antigen-driven disease of the esophagus. Tissue EoE pathology has previously been extensively characterized by novel transcriptomics and proteomic platforms, however the majority of surface marker determination and screening has been performed in blood due to mucosal tissue size limitations. While eosinophils, CD4+ T cells, mast cells and natural killer (NK) T cells were previously investigated in the context of EoE, an accurate picture of the composition of peripheral blood mononuclear cells (PBMC) and their activation is missing. Methods: In this study, we aimed to comprehensively analyze the composition of peripheral blood mononuclear cells and their activation using surface marker measurements with multicolor flow cytometry simultaneously in both blood and mucosal tissue of patients with active EoE, inactive EoE, patients with gastroesophageal reflux disease (GERD) and controls. Moreover, we set out to validate our data in co-cultures of PBMC with human primary esophageal epithelial cells and in a novel inducible mouse model of eosinophilic esophagitis, characterized by extensive IL-33 secretion in the esophagus. Results: Our results indicate that specific PBMC populations are enriched, and that they alter their surface expression of activation markers in mucosal tissue of active EoE. In particular, we observed upregulation of the immunomodulatory molecule CD38 on CD4+ T cells and on myeloid cells in biopsies of active EoE. Moreover, we observed significant upregulation of PD-1 on CD4+ and myeloid cells, which was even more prominent after corticosteroid treatment. With co-culture experiments we could demonstrate that direct cell contact is needed for PD-1 upregulation on CD4+ T cells. Finally, we validated our findings of PD-1 and CD38 upregulation in an inducible mouse model of EoE. Discussion: Herein we show significant alterations in the PBMC activation profile of patients with active EoE in comparison to inactive EoE, GERD and controls, which could have potential implications for treatment. To our knowledge, this study is the first of its kind expanding the multi-color flow cytometry approach in different patient groups using in vitro and in vivo translational models.

Utilization of Topical Polysporin and Triamcinolone for the Treatment of Hypergranulation Tissue.

Hypergranulation is the abnormal accumulation of granulation tissue in a wound and is commonly seen in burns. It impairs wound healing and can predispose patients to infection. There is no gold standard treatment for hypergranulation tissue, but some options include surgical debridement, chemical cautery with silver nitrate, and topical steroids. Silver nitrate treatment is painful and can lead to scarring, so topical steroid use is on the rise. A retrospective review, between January 1, 2017 and August 30, 2021, at a tertiary burn center was performed to analyze outcomes of hypergranulation tissue after treatment with a topical 50/50 mixture of triamcinolone (Perrigo, Dublin, Ireland) and Polysporin (Johnson & Johnson, New Brunswick, NJ). One hundred and sixteen patients were treated with triamcinolone and Polysporin for hypergranulation tissue, although 24 did not meet inclusion criteria. Eighty-eight out of 92 patients were successfully treated until hypergranulation resolution, while 4/92(4.3%) required silver nitrate or surgery despite the topical cream to achieve resolution. In the 88 patients successfully treated until hypergranulation resolution, 99 areas of hypergranulation were treated. Forty-one of 99 (41.4%) hypergranulation areas resolved within 2 weeks. The average time to hypergranulation resolution was 27.5 ± 2.5 days. We found that a novel 50/50 mixture of triamcinolone and Polysporin topical ointment is an effective and safe treatment for hypergranulation tissue in burn wounds. Further prospective studies are needed to determine its efficacy and safety profile.

Barriers to Timely Diagnosis of Eosinophilic Gastrointestinal Diseases.

Although eosinophilic gastrointestinal diseases, including eosinophilic esophagitis, have been described over the past 2 to 3 decades, barriers to diagnosis and treatment are common and compounded by issues related to social determinants of health, race, ethnicity, and access to care. These barriers contribute to delays in diagnosis, resulting in persistent inflammation in the gastrointestinal tract, which can have significant consequences, including fibrostenotic complications in adults, failure to thrive in children, and decreased quality of life in all affected patients. In this commentary, we summarize gaps in knowledge regarding the epidemiology of eosinophilic gastrointestinal diseases, highlight barriers to diagnosis, discuss potential approaches based on best practices in other atopic and chronic gastrointestinal diseases, and provide recommendations for reducing barriers to timely diagnosis of eosinophilic gastrointestinal diseases in underserved populations.

Primary B cell lymphoma of the patella presenting as anterior knee pain: A case report.

Case: A 76-year-old female with a history of multiple falls on the patella presented with worsening knee pain, swelling, and reduced range of motion. Radiographs revealed tricompartmental osteoarthritis and subtle erosion of the posterior cortex of the patella that was missed by the referring orthopedist and radiologist. Her persistent pain prompted an MRI, revealing a mass later confirmed to be primary diffuse large B-cell lymphoma of the patella after biopsy and appropriate metastatic workup. Conclusion: Primary B-cell patellar lymphoma is a rarely described cause of knee pain requiring broad differential diagnosis and multidisciplinary workup in order to avoid erroneous treatment and ensure prompt oncologic treatment.

Breakthroughs in understanding and treating eosinophilic gastrointestinal diseases presented at the CEGIR/TIGERs Symposium at the 2022 American Academy of Allergy, Asthma & Immunology Meeting.

The Consortium of Eosinophilic Gastrointestinal Diseases and The International Gastrointestinal Eosinophil Researchers organized a day-long symposium at the 2022 Annual Meeting of the American Academy of Allergy, Asthma & Immunology. The symposium featured a review of recent discoveries in the basic biology and pathogenesis of eosinophilic gastrointestinal diseases (EGIDs) in addition to advances in our understanding of the clinical features of EGIDs. Diagnostic and management approaches were reviewed and debated, and clinical trials of emerging therapies were highlighted. Herein, we briefly summarize the breakthrough discoveries in EGIDs.

Common microRNA regulated pathways in Alzheimer's and Parkinson's disease.

MicroRNAs (miRNAs) are small non-coding RNAs involved in gene regulation. Recently, miRNA dysregulation has been found in neurodegenerative diseases such as Alzheimer's disease (AD) and Parkinson's disease (PD). The diagnosis of Alzheimer's and Parkinson's is currently challenging, mainly occurring when pathology is already present, and although treatments are available for both diseases, the role of treatment is primarily to prevent or delay the progress of the diseases instead of fully overcoming the diseases. Therefore, the challenge in the near future will be to determine effective drugs to tackle the dysregulated biological pathways in neurodegenerative diseases. In the present study, we describe the dysregulation of miRNAs in blood of Alzheimer's and Parkinson's patients with the aim to identify common mechanisms between the 2 pathologies and potentially to identify common therapeutic targets which can stop or delay the progression of two most frequent neuropathologies. Two independent systematic reviews, bioinformatic analysis, and experiment validation were performed to identify whether AD and PD share common pathways. A total of 15 common miRNAs were found in the literature and 13 common KEGG pathways. Among the common miRNAs, two were selected for validation in a small cohort of AD and PD patients. Let-7f-5p and miR-29b-3p showed to be good predictors in blood of PD patients.

Ethical Implications of Continuing Oral Immunotherapy After the Development of Eosinophilic Esophagitis.

Eosinophilic esophagitis (EoE) is a chronic allergic inflammatory disease requiring maintenance therapy. Traditionally, EoE has been a contraindication to oral immunotherapy (OIT) and a rationale for discontinuing treatment because OIT may induce EoE. Most, but not all patients with OIT-induced EoE experience symptom resolution and histologic remission after discontinuing OIT. Recent studies report OIT continuation even after EoE onset, despite the previously accepted standard of care. This creates clinical as well as ethical challenges for allergists treating these patients. Considering the published literature on EoE and OIT and the primary medical ethics principles of beneficence, nonmaleficence, autonomy, and justice, we discuss the ethical implications of pursuing desensitization despite the potential complications associated with EoE. When ethical principles are in opposition, shared decision-making should be employed to determine whether OIT should be continued after an EoE diagnosis. This article highlights the ethical dilemmas allergists face when determining whether patients with a diagnosis of EoE should continue OIT.

Enhancing diversity, equity, inclusion, and accessibility in eosinophilic gastrointestinal disease research: the consortium for eosinophilic gastrointestinal disease researchers' journey.

In response to the social inequities that exist in health care, the NIH-funded Consortium of Eosinophilic Gastrointestinal Disease Researchers (CEGIR) recently formed a diversity committee to examine systemic racism and implicit bias in the care and research of eosinophilic gastrointestinal diseases (EGIDs). Herein, we describe our process, highlighting milestones and issues addressed since the committee's inception, which we hope will inspire other researchers to enhance diversity, equity, inclusion, and accessibility (DEIA) in their fields. Our journey began by establishing mission and vision statements to define the purpose of the committee. Regular discussion of diversity-related topics was incorporated into existing meetings and web-based materials were shared. This was followed by educational initiatives, including establishing a library of relevant publications and a speaker series to address DEIA topics. We then established a research agenda focused on the following actionable items: (1) to define what is known about the demographics of EGIDs by systematic review of population-based studies; (2) to develop a practical tool for reporting participant demographics to reduce bias in EGID literature; (3) to examine health disparities in the care of individuals with eosinophilic esophagitis who present to the emergency department with an esophageal food impaction; (4) to examine how access to a gastroenterologist affects the conclusions of published research examining the prevalence of pediatric eosinophilic esophagitis; and (5) to develop a model for examining the dimensions of diversity, and provide a framework for CEGIR's ongoing projects and data capture. In addition to promoting consciousness of DEIA, this initiative has fostered inclusivity among CEGIR members and will continue to inspire positive changes in EGID care and research.

Diversity in Eosinophilic Gastrointestinal Disease Research To address systemic bias in patient care and research in eosinophilic gastrointestinal diseases, the Consortium of Eosinophilic Gastrointestinal Disease Researchers (CEGIR) recently formed a diversity committee. The CEGIR diversity committee has defined its purpose through mission and vision statements and developed structured educational and research initiatives to enhance diversity, equity, inclusivity, and accessibility (DEIA) in all CEGIR activities. Here, we share the process of formation of our diversity committee, highlighting milestones achieved and summarizing future directions. We hope that this report will serve as a guide and an inspiration for other researchers to enhance DEIA in their fields.

IL-13-induced STAT3-dependent signaling networks regulate esophageal epithelial proliferation in eosinophilic esophagitis.

BACKGROUND: Basal zone hyperplasia (BZH) and dilated intercellular spaces (DISs) are thought to contribute to the clinical manifestations of eosinophilic esophagitis (EoE); however, the molecular pathways that drive BZH remain largely unexplored. OBJECTIVE: We sought to define the role of IL-13-induced transcriptional programs in esophageal epithelial proliferation in EoE. METHODS: We performed RNA sequencing, bioinformatics, Western blot, reverse transcriptase quantitative PCR, and histologic analyses on esophageal biopsies from healthy control and patients with EoE, primary esophageal cells derived from patients with EoE, and IL-13-stimulated esophageal epithelial keratinocytes grown at the air-liquid interface (EPC2-ALI). Genetic (shRNA) and pharmacologic (proteolysis-targeting chimera degrader) approaches and in vivo model of IL-13-induced esophageal epithelial remodeling (Krt5-rtTA x tetO-IL-13Tg) were used to define the role of signal transducer and activator of transcription 3 (STAT3) and STAT6 and secreted frizzled-related protein 1 (SFRP1) in esophageal epithelial proliferation. RESULTS: RNA-sequencing analysis of esophageal biopsies (healthy control vs EoE) and EPC2-ALI revealed 82 common differentially expressed genes that were enriched for putative STAT3 target genes. In vitro and in vivo analyses revealed a link between IL-13-induced STAT3 and STAT6 phosphorylation, SFRP1 mRNA expression, and esophageal epithelial proliferation. In vitro studies showed that IL-13-induced esophageal epithelial proliferation was STAT3-dependent and regulated by the STAT3 target SFRP1. SFRP1 mRNA is increased in esophageal biopsies from patients with active EoE compared with healthy controls or patients in remission and identifies an esophageal suprabasal epithelial cell subpopulation that uniquely expressed the core EoE proinflammatory transcriptome genes (CCL26, ALOX15, CAPN14, ANO1, and TNFAIP6). CONCLUSIONS: These studies identify SFRP1 as a key regulator of IL-13-induced and STAT3-dependent esophageal proliferation and BZH in EoE and link SFRP1+ esophageal epithelial cells with the proinflammatory and epithelial remodeling response in EoE.