1-Food versus 4-Food Elimination Diet for Pediatric Eosinophilic Esophagitis: A Multi-site Randomized Trial.

BACKGROUND: A 6-food elimination diet in pediatric eosinophilic esophagitis (EoE) is difficult to implement and may negatively impact quality of life (QoL). Less restrictive elimination diets may balance QoL and efficacy. OBJECTIVE: We performed a multi-site, randomized comparative efficacy trial of a 1-food (milk) elimination diet (1FED) versus 4-food (milk, egg, wheat, soy) elimination diet (4FED) in pediatric EoE. METHODS: Patients aged 6 to 17 years with histologically active and symptomatic EoE were randomized 1:1 to 1FED or 4FED for 12 weeks. Primary endpoint was symptom improvement by Pediatric EoE Symptom Score (PEESSv2.0). Secondary endpoints were proportion achieving histologic remission (<15 eosinophils/high-power field [eos/hpf]); change in histologic features (histology scoring system [HSS]), endoscopic severity (endoscopic reference score [EREFS]), transcriptome (EoE diagnostic panel [EDP]), and QoL scores; and predictors of remission. RESULTS: 63 patients were randomly assigned to 1FED (n=38) and 4FED (n=25). In 4FED versus 1FED, mean PEESSv2.0 improved -25.0 versus -14.5 (p=0.04) but remission rates (41% versus 44%; p=1.00), HSS (-0.25 versus -0.29; p=0.77), EREFS (-1.10 versus -0.58; p=0.47) and QoL scores were similar between groups. The EoE transcriptome normalized in histologic responders to both diets. Baseline peak eosinophil count predicted remission (OR 0.975, 95% CI 0.953-0.999, p=0.04; cut-off ≤42 eos/hpf). The 4FED withdrawal rate (32%) exceeded 1FED (11%) (p=0.0496). CONCLUSIONS: Although 4FED moderately improved symptoms compared to 1FED, the histologic, endoscopic, QoL, and transcriptomic outcomes were similar in both groups. 1FED is a reasonable first choice therapy for pediatric EoE given its effects, tolerability, and relative simplicity.

Joint genotype and ancestry analysis identify novel loci associated with atopic dermatitis in African American population.

Atopic dermatitis (AD) is a chronic itchy inflammatory disease of the skin. Genetic studies have identified multiple risk factors linked to the disease; however, most of studies have been derived from European and East Asian populations. The admixed genome of African American (AA) may provide an opportunity to discovery ancestry-specific loci involved in AD susceptibility. Herein, we present joint analysis of ancestry and genotype effects followed with validation using differential gene expression analysis on AD using 710 AD cases and 1015 non-AD controls from the AA population, genotyped using MEGA followed by imputation using the CAAPA reference panel. The joint analysis identified two novel AD-susceptibility loci, rs2195989 in gene ANGPT1 (8q23.1) and rs62538818 in the intergenic region LURAP1L-MPDZ (9p23). Admixture mapping (AM) results showed potential genomic inflation, and we implemented genomic control and identified five ancestry-of-origin loci with European ancestry effects. The multi-omics functional prioritization of variants in AM signals prioritized the loci SLAIN2, RNF39, and FOXA2. GWAS identified variants significantly associated with AD in the AA population, including SGK1 (rs113357522, OR = 2.81), EFR3A (rs16904552, OR = 1.725), and MMP14 (rs911912, OR = 1.791). GWAS variants were common in the AA but rare in the European population, which suggests an African ancestry-specific risk of AD. Four genes (ANGPT1, LURAP1L, EFR3A, and SGK1) were further validated using qPCR from AD and healthy skin. This study highlighted the importance of genetic studies on admixed populations, as well as local ancestry and genotype-ancestry joint effects to identify risk loci for AD.

Amniotic Fluid Modifies Esophageal Epithelium Differentiation and Inflammatory Responses.

The interplay between genetic and environmental factors during pregnancy can predispose to inflammatory diseases postnatally, including eosinophilic esophagitis, a chronic allergic disease triggered by food. Herein, we examined the effects of amniotic fluid (AF) on esophageal epithelial differentiation and responsiveness to pro-allergic stimuli. Multiplex analysis of AF revealed the expression of 66 cytokines, whereas 5 cytokines including IL-4 and TSLP were not detected. Several pro-inflammatory cytokines including TNFa and IL-12 were highly expressed in the AF from women who underwent preterm birth, while EGF was the highest in term birth samples. Exposure of esophageal epithelial cells to AF resulted in transient phosphorylation of ERK1/2 and the transcription of early response genes, highlighting the direct impact of AF on esophageal epithelial cells. In a 3-dimensional spheroid model, AF modified the esophageal epithelial differentiation program and enhanced the transcription of IL-13-target genes, including CCL26 and CAPN14, which encodes for a major genetic susceptibility locus for eosinophilic esophagitis. Notably, CAPN14 exhibited upregulation in spheroids exposed to preterm but not term AF following differentiation. Collectively, our findings call attention to the role of AF as a potential mediator of the intrauterine environment that influences subsequent esophageal disorders.

TH2 cell compensatory effect following benralizumab treatment for eosinophilic gastritis.

BACKGROUND: Eosinophil accumulation is a main feature of eosinophilic gastritis (EoG) and is associated with its histologic diagnosis and pathology. However, a recent clinical trial has demonstrated that EoG endoscopic, noneosinophil histologic, and clinical features remain persistent despite complete eosinophil depletion. OBJECTIVE: Our aim was to examine gastric T-cell composition and associated cytokine levels of patients with EoG following benralizumab-induced eosinophil depletion versus following administration of placebo. METHODS: A cohort of subjects with EoG from a subset of subjects who participated in a recent phase 2 benralizumab trial was treated for 12 weeks with administration of 3 doses of benralizumab (anti-IL-5 receptor α antibody [n = 5]) or placebo (n = 4). Single-cell suspensions obtained by gastric biopsy were stimulated with phorbol 12,13-dibutyrate and ionomycin in the presence of brefeldin A and monensin. Harvested cells were fixed, stained, and analyzed by flow cytometry to examine T-cell populations and associated cytokines. RESULTS: Following benralizumab treatment but not placebo, blood and gastric eosinophil levels decreased 16-fold and 10-fold, respectively. Whereas histologic score and features were significantly decreased, no change was observed in endoscopic score and features. Following complete eosinophil depletion with benralizumab, gastric TH2 cell levels were 3-fold higher than the levels in the patients with EoG who were given placebo; and the levels of associated type 2 cytokine production of IL-4, IL-5, and IL-13 in the benralizumab-treated patients were, respectively, 4-, 5.5-, and 2.5-fold, higher than those in the placebo-treated patients. CONCLUSION: We have identified a putative positive feedback loop whereby eosinophil depletion results in a paradoxic increase in levels of TH2 cells and derived cytokines; this finding suggests an explanation for the limited success of eosinophil depletion as monotherapy in eosinophil-associated gastrointestinal disorders.

Losartan Treatment Reduces Esophageal Eosinophilic Inflammation in a Subset of Eosinophilic Esophagitis.

BACKGROUND: Eosinophilic esophagitis (EoE) is a chronic, food antigen-driven esophageal disorder. Connective tissue disorders (CTDs) and esophageal connective tissue alterations are associated with EoE. Therefore, angiotensin II type 1 receptor blockade with losartan, an accepted CTD treatment, is a potential EoE treatment. OBJECTIVE: We evaluated losartan's effects on esophageal pathology, symptoms, and safety in patients with EoE with and without a CTD in an open-label, non-placebo controlled multisite study. METHODS: Fifteen participants with EoE, aged 5 to 23 years, underwent treatment with per-protocol titrated doses of losartan in an open-label, 16-week pilot trial. Losartan was added to standard of care therapy and 14 patients completed the study. Eosinophil counts served as the primary end point, whereas we also assessed the EoE Histology Scoring System, Endoscopic Reference Scores, EoE Diagnostic Panel, and patient-reported outcomes. RESULTS: Esophageal eosinophilia was not reduced after losartan. The peak eosinophil count was not reduced for the proximal (median [interquartile range]: -3 [-22 to 3]; P = .49) and distal esophagus (median [interquartile range]: -18 [-39 to -1]; P = .23). There were no differences in losartan response in EoE with or without CTD (n = 7 and 8, respectively). Regardless, in a small subset of four participants esophageal eosinophilia was resolved with a concomitant reduction in EoE Histology Scoring System score and Endoscopic Reference Score. Across all subjects, the Pediatric EoE Symptom Score, Pediatric Quality of Life Inventory EoE Module, and EoE Diagnostic Panel improved after losartan (P < .05). CONCLUSIONS: Losartan treatment was associated with improved patient-reported outcome scores and EoE Diagnostic Panel biomarkers although without a reduction in esophageal eosinophilia overall. A subset of patients demonstrated improved histopathologic and endoscopic features that could not be tied to a specific feature predicting response to treatment.

Long-term durability between parent and child patient-reported outcomes in eosinophilic esophagitis.

BACKGROUND: Because young children cannot self-report symptoms, there is a need for parent surrogate reports. Although early work suggested parent-child alignment for eosinophil esophagitis (EoE) patient-reported outcomes (PROs), the longitudinal alignment is unclear. OBJECTIVE: We sought to assess the agreement and longitudinal stability of PROs between children with EoE and their parents. METHODS: A total of 292 parent-child respondents completed 723 questionnaires over 5 years in an observational trial in the Consortium of Eosinophilic Gastrointestinal Disease Researchers. The change in and agreement between parent and child Pediatric Eosinophilic Esophagitis Symptom Score version 2 (PEESSv2.0) and Pediatric Quality of Life Eosinophilic Esophagitis Module (PedsQL-EoE) PROs over time were assessed using Pearson correlation and Bland-Altman analyses. Clinical factors influencing PROs and their agreement were evaluated using linear mixed models. RESULTS: The cohort had a median disease duration equaling 3.7 years and was predominantly male (73.6%) and White (85.3%). Child and parent PEESSv2.0 response groups were identified and were stable over time. There was strong correlation between child and parent reports (PEESSv2.0, 0.83;PedsQL-EoE, 0.74), with minimal pairwise differences for symptoms. Longitudinally, parent-reported PedsQL-EoE scores were stable (P ≥ .32), whereas child-reported PedsQL-EoE scores improved (P = .026). A larger difference in parent and child PedsQL-EoE reports was associated with younger age (P < .001), and differences were driven by psychosocial PRO domains. CONCLUSIONS: There is strong longitudinal alignment between child and parent reports using EoE PROs. These data provide evidence that parent report is a stable proxy for objective EoE symptoms in their children.

Single-cell RNA-sequencing of human eosinophils in allergic inflammation in the esophagus.

BACKGROUND: Eosinophils are elusive cells involved in allergic inflammation. Single-cell RNA-sequencing (scRNA-seq) is an emerging approach to deeply characterize cellular properties, heterogeneity, and functionality. OBJECTIVES: We sought to comprehensively characterize the transcriptome and biological functions of human eosinophils at a site of severe allergic inflammation in the esophagus (ie, eosinophilic esophagitis [EoE]). METHODS: We employed a gravity-based scRNA-seq methodology to sequence blood eosinophils from patients with EoE and control individuals compared to a reanalyzed public scRNA-seq dataset of human esophageal eosinophils of EoE patients. We used flow cytometry, immunostaining, and a stimulation assay to verify mRNA findings. RESULTS: In total, scRNA-seq was obtained from 586 eosinophils (188 from blood [n = 6 individuals] and 398 from esophagus [n = 6 individuals]). The esophageal eosinophils were composed of a population of activated eosinophils (enriched in 659 genes compared with peripheral blood-associated eosinophils) and a small population of eosinophils resembling peripheral blood eosinophils (enriched in 62 genes compared with esophageal eosinophils). Esophageal eosinophils expressed genes involved in sensing and responding to diverse stimuli, most notably IFN-γ, IL-10, histamine and leukotrienes, and succinate. Esophageal eosinophils were most distinguished from other esophageal populations by gene expression of the receptors CCR3, HRH4, SUCNR1, and VSTM1; transcription factors CEBPE, OLIG1, and OLIG2; protease PRSS33; and the hallmark eosinophil gene CLC. A web of bidirectional eosinophil interactions with other esophageal populations was derived. Comparing esophageal eosinophils and mast cells revealed that esophageal eosinophils expressed genes involved in DNAX-activation protein-12 (also known as TYROBP) interactions, IgG receptor-triggered events, immunoregulation, and IL-10 signaling. CONCLUSIONS: In EoE, esophageal eosinophils exist as 2 populations, a minority population resembling blood eosinophils and the other population characterized by high de novo transcription of diverse sensing receptors and inflammatory mediators readying them to potentially intersect with diverse cell types.

Dupilumab for Eosinophilic Esophagitis in Patients 1 to 11 Years of Age.

BACKGROUND: Dupilumab is a human monoclonal antibody that blocks interleukin-4 and interleukin-13 pathways and has shown efficacy in five different atopic diseases marked by type 2 inflammation, including eosinophilic esophagitis in adults and adolescents. METHODS: In this phase 3 trial, we randomly assigned, in a 2:2:1:1 ratio, patients 1 to 11 years of age with active eosinophilic esophagitis who had had no response to proton-pump inhibitors to 16 weeks of a higher-exposure or lower-exposure subcutaneous dupilumab regimen or to placebo (two groups) (Part A). At the end of Part A, eligible patients in each dupilumab group continued the same regimen and those in the placebo groups were assigned to higher-exposure or lower-exposure dupilumab for 36 weeks (Part B). At each level of exposure, dupilumab was administered in one of four doses tiered according to baseline body weight. The primary end point was histologic remission (peak esophageal intraepithelial eosinophil count, ≤6 per high-power field) at week 16. Key secondary end points were tested hierarchically. RESULTS: In Part A, histologic remission occurred in 25 of the 37 patients (68%) in the higher-exposure group, in 18 of the 31 patients (58%) in the lower-exposure group, and in 1 of the 34 patients (3%) in the placebo group (difference between the higher-exposure regimen and placebo, 65 percentage points [95% confidence interval {CI}, 48 to 81; P<0.001]; difference between the lower-exposure regimen and placebo, 55 percentage points [95% CI, 37 to 73; P<0.001]). The higher-exposure dupilumab regimen led to significant improvements in histologic, endoscopic, and transcriptomic measures as compared with placebo. The improvements in histologic, endoscopic, and transcriptomic measures between baseline and week 52 in all the patients were generally similar to the improvements between baseline and week 16 in the patients who received dupilumab in Part A. In Part A, the incidence of coronavirus disease 2019, nausea, injection-site pain, and headache was at least 10 percentage points higher among the patients who received dupilumab (at either dose) than among those who received placebo. Serious adverse events were reported in 3 patients who received dupilumab during Part A and in 6 patients overall during Part B. CONCLUSIONS: Dupilumab resulted in histologic remission in a significantly higher percentage of children with eosinophilic esophagitis than placebo. The higher-exposure dupilumab regimen also led to improvements in measures of key secondary end points as compared with placebo. (Funded by Sanofi and Regeneron Pharmaceuticals; EoE KIDS ClinicalTrials.gov number, NCT04394351.).

Eosinophil Depletion with Benralizumab for Eosinophilic Esophagitis.

BACKGROUND: Benralizumab is an eosinophil-depleting anti-interleukin-5 receptor α monoclonal antibody. The efficacy and safety of benralizumab in patients with eosinophilic esophagitis are unclear. METHODS: In a phase 3, multicenter, double-blind, randomized, placebo-controlled trial, we assigned patients 12 to 65 years of age with symptomatic and histologically active eosinophilic esophagitis in a 1:1 ratio to receive subcutaneous benralizumab (30 mg) or placebo every 4 weeks. The two primary efficacy end points were histologic response (≤6 eosinophils per high-power field) and the change from baseline in the score on the Dysphagia Symptom Questionnaire (DSQ; range, 0 to 84, with higher scores indicating more frequent or severe dysphagia) at week 24. RESULTS: A total of 211 patients underwent randomization: 104 were assigned to receive benralizumab, and 107 were assigned to receive placebo. At week 24, more patients had a histologic response with benralizumab than with placebo (87.4% vs. 6.5%; difference, 80.8 percentage points; 95% confidence interval [CI], 72.9 to 88.8; P<0.001). However, the change from baseline in the DSQ score did not differ significantly between the two groups (difference in least-squares means, 3.0 points; 95% CI, -1.4 to 7.4; P = 0.18). There was no substantial between-group difference in the change from baseline in the Eosinophilic Esophagitis Endoscopic Reference Score, which reflects endoscopic abnormalities. Adverse events were reported in 64.1% of the patients in the benralizumab group and in 61.7% of those in the placebo group. No patients discontinued the trial because of adverse events. CONCLUSIONS: In this trial involving patients 12 to 65 years of age with eosinophilic esophagitis, a histologic response (≤6 eosinophils per high-power field) occurred in significantly more patients in the benralizumab group than in the placebo group. However, treatment with benralizumab did not result in fewer or less severe dysphagia symptoms than placebo. (Funded by AstraZeneca; MESSINA ClinicalTrials.gov number, NCT04543409.).

Transnasal Endoscopy Acquires Esophageal Biopsies Adequate for Comprehensive Pathology Evaluation in Patients With Eosinophilic Esophagitis.

BACKGROUND: Transnasal endoscopy (TNE) does not require general anesthesia, an attractive characteristic for monitoring eosinophilic esophagitis (EoE). We evaluated the adequacy of TNE-obtained esophageal biopsies using the EoE Histology Scoring System (EoEHSS). METHODS: The Cincinnati Center for Eosinophilic Disorders database was searched for esophageal biopsies obtained by the same endoscopist, using either TNE or conventional endoscopy (CE). Whole-slide biopsy images were evaluated. The Mann-Whitney test was used for median (interquartile range) values and Fisher exact test for categorical variables. P ≤ .05 was considered significant. RESULTS: Median age (P = .82) or height (P = .83) did not differ between TNE (n = 17) and CE (n = 17) groups. Although median largest piece size (mm2) differed between the groups (TNE: 0.59 (0.45, 0.86), CE: 2.24 (1.09, 2.82), P < .001), all 8 EoEHSS features were evaluated in each group; only 1 feature (lamina propria fibrosis) was missing in both groups (TNE: 19/34, CE: 11/34, P = .09). The median peak eosinophil count/high-power field differed (TNE: 3 (0, 29), CE: 16 (1, 66), P = .03), but overall grade (TNE: 0.17 (0.10, 0.29), CE: 0.22 (0.14, 0.46), P = .12), stage (TNE: 0.14 (0.10, 0.24), CE: 0.20 (0.10, 0.43), P = .15), and non-eosinophil-related individual EoEHSS scores did not differ. CONCLUSIONS: TNE- and CE-obtained esophageal biopsies are similarly sufficient for evaluation of key pathological features in EoE.

Human Epidemiology and RespOnse to SARS-CoV-2 (HEROS): Objectives, Design and Enrollment Results of a 12-City Remote Observational Surveillance Study of Households with Children using Direct-to-Participant Methods.

The Human Epidemiology and Response to SARS-CoV-2 (HEROS) is a prospective multi-city 6-month incidence study which was conducted from May 2020-February 2021. The objectives were to identify risk factors for SARS-CoV-2 infection and household transmission among children and people with asthma and allergic diseases, and to use the host nasal transcriptome sampled longitudinally to understand infection risk and sequelae at the molecular level. To overcome challenges of clinical study implementation due to the coronavirus pandemic, this surveillance study used direct-to-participant methods to remotely enroll and prospectively follow eligible children who are participants in other NIH-funded pediatric research studies and their household members. Households participated in weekly surveys and biweekly nasal sampling regardless of symptoms. The aim of this report is to widely share the methods and study instruments and to describe the rationale, design, execution, logistics and characteristics of a large, observational, household-based, remote cohort study of SARS-CoV-2 infection and transmission in households with children. The study enrolled a total of 5,598 individuals, including 1,913 principal participants (children), 1,913 primary caregivers, 729 secondary caregivers and 1,043 other household children. This study was successfully implemented without necessitating any in-person research visits and provides an approach for rapid execution of clinical research.

Eosinophil Specialization Is Regulated by Exposure to the Esophageal Epithelial Microenvironment.

Distinct subsets of eosinophils are reported in inflammatory and healthy tissues, yet the functions of uniquely specialized eosinophils and the signals that elicit them, particularly in eosinophilic esophagitis (EoE), are not well understood. Herein, we report an ex-vivo system wherein freshly isolated human eosinophils were cocultured with esophageal epithelial cells and disease-relevant pro-inflammatory (IL-13) or pro-fibrotic (TGF-ß) cytokines. Compared with untreated cocultures, IL-13 increased expression of CD69 on eosinophils, whereas TGF-ß increased expression of CD81, CD62L, and CD25. Eosinophils from IL-13-treated cocultures demonstrated increased secretion of GRO-α, IL-8, and M-CSF and also generated increased extracellular peroxidase activity following activation. Eosinophils from TGF-ß-treated cocultures secreted increased IL-6 and exhibited increased chemotactic response to CCL11 compared with eosinophils from untreated or IL-13-treated coculture conditions. When eosinophils from TGF-ß-treated cocultures were cultured with fibroblasts, they upregulated SERPINE1 expression and fibronectin secretion by fibroblasts compared with eosinophils that were cultured with GM-CSF, alone. Translational studies revealed that CD62L was heterogeneously expressed by eosinophils in patient biopsies. Our results demonstrate that disease-relevant pro-inflammatory and pro-fibrotic signals present in the esophagus of EoE patients cause distinct profiles of eosinophil activation and gene expression.

Clinical and molecular correlates of the Index of Severity for Eosinophilic Esophagitis.

BACKGROUND: The Index of Severity for Eosinophilic Esophagitis (I-SEE) is a new expert-defined clinical tool that classifies disease severity of eosinophilic esophagitis (EoE). OBJECTIVE: We aimed to determine whether I-SEE is associated with patient characteristics, molecular features of EoE, or both. METHODS: We analyzed a prospective cohort of patients with EoE from the Consortium of Eosinophilic Gastrointestinal Disease Researchers (CEGIR). Associations between I-SEE and clinical and molecular features (assessed by an EoE diagnostic panel [EDP]) were assessed. RESULTS: In 318 patients with chronic EoE (209 adults, 109 children), median total I-SEE score was 7.0, with a higher symptoms and complications score in children than adults (4.0 vs 1.0; P < .001) and higher inflammatory and fibrostenotic features scores in adults than children (3.0 vs 1.0 and 3.0 vs 0, respectively; both P < .001). Total I-SEE score had a bimodal distribution with the inactive to moderate categories and severe category. EDP score correlated with total I-SEE score (r = -0.352, P < .001) and both inflammatory and fibrostenotic features scores (r = -0.665, P < .001; r = -0.446, P < .001, respectively), but not with symptoms and complications scores (r = 0.047, P = .408). Molecular severity increased from inactive to mild and moderate, but not severe, categories. Longitudinal changes of modified I-SEE scores and inflammatory and fibrostenotic features scores reflected histologic and molecular activity. CONCLUSIONS: I-SEE score is associated with select clinical features across severity categories and with EoE molecular features for nonsevere categories, warranting further validation.

Nonepithelial Gene Expression Correlates With Symptom Severity in Adults With Eosinophilic Esophagitis.

BACKGROUND: The mechanistic basis of the variable symptomatology seen in eosinophilic esophagitis (EoE) remains poorly understood. OBJECTIVE: We examined the correlation of a validated, patient-reported outcome metric with a broad spectrum of esophageal transcripts to uncover potential symptom pathogenesis. METHODS: We extracted data from 146 adults with EoE through the Consortium of Eosinophilic Gastrointestinal Disease Researchers. Patients were subgrouped by esophageal dilation history. We compared a validated patient-reported outcome metric, the EoE Activity Index (EEsAI), with a set of transcripts expressed in the esophagus of patients with EoE, the EoE Diagnostic Panel (EDP). We used single-cell RNA sequencing data to identify the cellular source of EEsAI-related EDP genes and further analyzed patients with mild and severe symptoms. RESULTS: The EEsAI correlated with the EDP total score, especially in patients without recent esophageal dilation (r = -0.31; P = .003). We identified 14 EDP genes that correlated with EEsAI scores (r ≥ 0.3; P < .05). Of these, 11 were expressed in nonepithelial cells and three in epithelial cells. During histologic remission, only four of 11 nonepithelial genes (36%) versus all three epithelial genes (100%) had decreased expression to less than 50% of that in active EoE. Fibroblasts expressed five of 11 nonepithelial EEsAI-associated EDP genes (45%). A subset of nonepithelial genes (eight of 11; 73%), but not EoE-representative genes (none of four; 0%; CCL26, CAPN14, DSG1, and SPINK7), was upregulated in patients with EoE with the highest versus lowest symptom burden. CONCLUSION: The correlation of symptoms and nonepithelial esophageal gene expression substantiates that nonepithelial cells (eg, fibroblasts) likely contribute to symptom severity.

Common and disparate clinical presentations and mechanisms in different eosinophilic gastrointestinal diseases.

Eosinophilic gastrointestinal diseases (EGIDs) are a group of diseases characterized by selective eosinophil infiltration of the gastrointestinal (GI) tract in the absence of other causes of eosinophilia. These diseases are generally driven by type 2 inflammation, often in response to food allergen exposure. Among all EGIDs, the clinical presentation often includes a history of atopic disease with a variety of GI symptoms. EGIDs are traditionally separated into eosinophilic esophagitis (EoE) and non-EoE EGIDs. EoE is relatively better understood and now associated with clinical guidelines and 2 US Food and Drug Administration-approved treatments, whereas non-EoE EGIDs are rarer and less well-understood diseases without US Food and Drug Administration-approved treatments. Non-EoE EGIDs are further subclassified by the area of the GI tract that is involved; they comprise eosinophilic gastritis, eosinophilic enteritis (including eosinophilic duodenitis), and eosinophilic colitis. As with other GI disorders, the disease presentations and mechanisms differ depending on the involved segment of the GI tract; however, the differences between EoE and non-EoE EGIDs extend beyond which GI tract segment is involved. The aim of this article is to summarize the commonalities and differences between the clinical presentations and disease mechanisms for EoE and non-EoE EGIDs.

Impact of the COVID-19 Pandemic on People Living With Rare Diseases and Their Families: Results of a National Survey.

BACKGROUND: With more than 103 million cases and 1.1 million deaths, the COVID-19 pandemic has had devastating consequences for the health system and the well-being of the entire US population. The Rare Diseases Clinical Research Network funded by the National Institutes of Health was strategically positioned to study the impact of the pandemic on the large, vulnerable population of people living with rare diseases (RDs). OBJECTIVE: This study was designed to describe the characteristics of COVID-19 in the RD population, determine whether patient subgroups experienced increased occurrence or severity of infection and whether the pandemic changed RD symptoms and treatment, and understand the broader impact on respondents and their families. METHODS: US residents who had an RD and were <90 years old completed a web-based survey investigating self-reported COVID-19 infection, pandemic-related changes in RD symptoms and medications, access to care, and psychological impact on self and family. We estimated the incidence of self-reported COVID-19 and compared it with that in the US population; evaluated the frequency of COVID-19 symptoms according to self-reported infection; assessed infection duration, complications and need for hospitalization; assessed the influence of the COVID-19 pandemic on RD symptoms and treatment, and whether the pandemic influenced access to care, special food and nutrition, or demand for professional psychological assistance. RESULTS: Between May 2, 2020, and December 15, 2020, in total, 3413 individuals completed the survey. Most were female (2212/3413, 64.81%), White (3038/3413, 89.01%), and aged ≥25 years (2646/3413, 77.53%). Overall, 80.6% (2751/3413) did not acquire COVID-19, 2.08% (71/3413) acquired it, and 16.58% (566/3413) did not know. Self-reported cases represented an annual incidence rate of 2.2% (95% CI 1.7%-2.8%). COVID-19 cases were more than twice the expected (71 vs 30.3; P<.001). COVID-19 was associated with specific symptoms (loss of taste: odds ratio [OR] 38.9, 95% CI 22.4-67.6, loss of smell: OR 30.6, 95% CI 17.7-53.1) and multiple symptoms (>9 symptoms vs none: OR 82.5, 95% CI 29-234 and 5-9: OR 44.8, 95% CI 18.7-107). Median symptom duration was 16 (IQR 9-30) days. Hospitalization (7/71, 10%) and ventilator support (4/71, 6%) were uncommon. Respondents who acquired COVID-19 reported increased occurrence and severity of RD symptoms and use or dosage of select medications; those who did not acquire COVID-19 reported decreased occurrence and severity of RD symptoms and use of medications; those who did not know had an intermediate pattern. The pandemic made it difficult to access care, receive treatment, get hospitalized, and caused mood changes for respondents and their families. CONCLUSIONS: Self-reported COVID-19 was more frequent than expected and was associated with increased prevalence and severity of RD symptoms and greater use of medications. The pandemic negatively affected access to care and caused mood changes in the respondents and family members. Continued surveillance is necessary.

Machine learning-based identification and characterization of mast cells in eosinophilic esophagitis.

BACKGROUND: Eosinophilic esophagitis (EoE) is diagnosed and monitored using esophageal eosinophil levels; however, EoE also exhibits a marked, understudied esophageal mastocytosis. OBJECTIVES: Using machine learning, we localized and characterized esophageal mast cells (MCs) to decipher their potential role in disease pathology. METHODS: Esophageal biopsy samples (EoE, control) were stained for MCs by anti-tryptase and imaged using immunofluorescence; high-resolution whole tissue images were digitally assembled. Machine learning software was trained to identify, enumerate, and characterize MCs, designated Mast Cell-Artificial Intelligence (MC-AI). RESULTS: MC-AI enumerated cell counts with high accuracy. During active EoE, epithelial MCs increased and lamina propria (LP) MCs decreased. In controls and EoE remission patients, papillae had the highest MC density and negatively correlated with epithelial MC density. MC density in the epithelium and papillae correlated with the degree of epithelial eosinophilic inflammation, basal zone hyperplasia, and LP fibrosis. MC-AI detected greater MC degranulation in the epithelium, papillae, and LP in patients with EoE compared with control individuals. MCs were localized further from the basement membrane in active EoE than EoE remission and control individuals but were closer than eosinophils to the basement membrane in active EoE. CONCLUSIONS: Using MC-AI, we identified a distinct population of homeostatic esophageal papillae MCs; during active EoE, this population decreases, undergoes degranulation, negatively correlates with epithelial MC levels, and significantly correlates with distinct histologic features. Overall, MC-AI provides a means to understand the potential involvement of MCs in EoE and other disorders.