High Body Mass Index and Response to Anti-Tumor Necrosis Factor Therapy in Pediatric Crohn's Disease.

INTRODUCTION: Obesity is common among patients with pediatric Crohn's disease (PCD). Some adult studies suggest obese patients respond less well to anti-tumor necrosis factor (TNF) treatment. This study sought compares anti-TNF response and anti-TNF levels between pediatric patients with normal and high body mass index (BMI). METHODS: The COMBINE trial compared anti-TNF monotherapy with combination therapy with methotrexate in patients with PCD. In this secondary analysis, a comparison of time-to-treatment failure among patients with normal BMI vs BMI Z -score >1, adjusting for prescribed anti-TNF (infliximab [IFX] or adalimumab [ADA]), trial treatment assignment (combination vs monotherapy), and relevant covariates. Median anti-TNF levels across BMI category was also examined. RESULTS: Of 224 participants (162 IFX initiators and 62 ADA initiators), 111 (81%) had a normal BMI and 43 (19%) had a high BMI. High BMI was associated with treatment failure among ADA initiators (7/10 [70%] vs 12/52 [23%], hazard ratio 0.29, P = 0.007) but not IFX initiators. In addition, ADA-treated patients with a high BMI had lower ADA levels compared with those with normal BMI (median 5.8 vs 12.8 µg/mL, P = 0.02). IFX trough levels did not differ between BMI groups. DISCUSSION: Overweight and obese patients with PCD are more likely to experience ADA treatment failure than those with normal BMI. Higher BMI was associated with lower drug trough levels. Standard ADA dosing may be insufficient for overweight children with PCD. Among IFX initiators, there was no observed difference in clinical outcomes or drug levels, perhaps due to weight-based dosing and/or greater use of proactive drug monitoring.

Comparative Effectiveness of Anti-TNF in Combination With Low-Dose Methotrexate vs Anti-TNF Monotherapy in Pediatric Crohn's Disease: A Pragmatic Randomized Trial.

BACKGROUND & AIMS: Tumor necrosis factor inhibitors, including infliximab and adalimumab, are a mainstay of pediatric Crohn's disease therapy; however, nonresponse and loss of response are common. As combination therapy with methotrexate may improve response, we performed a multicenter, randomized, double-blind, placebo-controlled pragmatic trial to compare tumor necrosis factor inhibitors with oral methotrexate to tumor necrosis factor inhibitor monotherapy. METHODS: Patients with pediatric Crohn's disease initiating infliximab or adalimumab were randomized in 1:1 allocation to methotrexate or placebo and followed for 12-36 months. The primary outcome was a composite indicator of treatment failure. Secondary outcomes included anti-drug antibodies and patient-reported outcomes of pain interference and fatigue. Adverse events (AEs) and serious AEs (SAEs) were collected. RESULTS: Of 297 participants (mean age, 13.9 years, 35% were female), 156 were assigned to methotrexate (110 infliximab initiators and 46 adalimumab initiators) and 141 to placebo (102 infliximab initiators and 39 adalimumab initiators). In the overall population, time to treatment failure did not differ by study arm (hazard ratio, 0.69; 95% CI, 0.45-1.05). Among infliximab initiators, there were no differences between combination and monotherapy (hazard ratio, 0.93; 95% CI, 0.55-1.56). Among adalimumab initiators, combination therapy was associated with longer time to treatment failure (hazard ratio, 0.40; 95% CI, 0.19-0.81). A trend toward lower anti-drug antibody development in the combination therapy arm was not significant (infliximab: odds ratio, 0.72; 95% CI, 0.49-1.07; adalimumab: odds ratio, 0.71; 95% CI, 0.24-2.07). No differences in patient-reported outcomes were observed. Combination therapy resulted in more AEs but fewer SAEs. CONCLUSIONS: Among adalimumab but not infliximab initiators, patients with pediatric Crohn's disease treated with methotrexate combination therapy experienced a 2-fold reduction in treatment failure with a tolerable safety profile. CLINICALTRIALS: gov, Number: NCT02772965.

Subtyping of Eosinophilic Esophagitis Based on Disease Presentation in a pediatric Cohort.

OBJECTIVE: Eosinophilic esophagitis (EoE) is an immune-mediated inflammatory disease characterized by eosinophilic infiltration of esophageal tissue. Subtyping of EoE patients could be useful in predicting therapeutic response. We propose clinical subtypes, apply them to our pediatric EoE population retrospectively, and assess therapy choices and remission at one year. METHODS: A retrospective chart review of pediatric patients diagnosed with EoE was conducted. Patients were grouped into proposed subtypes (severe, allergic, fibrostenotic, inflammatory, unclassified) based on presenting characteristics. The primary outcome was histologic remission, which was defined <15 eosinophils/high-powered-field (hpf) at the closest visit 1 year postdiagnosis. RESULTS: Subtyping was possible in 242 of 256 patients and follow-up histological data were available in 75 subjects. The majority had an overlap in phenotype with 17% severe, 77% allergic, 15% fibrostenotic, 60% inflammatory, and 5% unclassified, whereas 45% of the cohort were assigned to a unique subtype. At 1 year, 43/75 (57%) of patients achieved histologic remission, with an overall average decrease of 33 (IQR -47, -12) eosinophils/hpf across the entire cohort. There was no difference in remission rates among subtypes. First-line therapy review revealed higher rates of proton pump inhibitor (PPI) ± topical steroids utilization in severe patients, while topical steroids were prescribed preferentially over dietary therapy in the fibrostenotic subtype. CONCLUSION: There were no observed differences in remission rates at 1 year among clinically defined subtypes of EoE, although this could be attributed to overlapping subtypes. Most patients responded well to medical therapy. Larger scale prospective studies designed to subtype patients and protocolize treatment may help personalize the approach to EoE management.

Contrast enhanced ultrasound: comparing a novel modality to MRI to assess for bowel disease in pediatric Crohn's patients.

BACKGROUND: To demonstrate the feasibility and reliability of a novel imaging modality, contrast enhanced ultrasound (CEUS), in evaluating for distal small bowel inflammation in pediatric Crohn's disease (CD), and compare this to concurrently obtained magnetic resonance imaging (MRI) findings. METHODS: Pediatric patients diagnosed with or having suspicion of CD with small bowel involvement, whose disease merited imaging with an MRI, concurrently underwent imaging with CEUS. We assessed the ability of CEUS to demonstrate distal small bowel disease by evaluating wall thickness, enhancement pattern, mucosal disruption and pericolonic inflammation. Concordance between imaging modalities was then assessed. RESULTS: Twenty patients were recruited for the study, 16 with known CD, 3 with concern for CD, and one with known colitis, but unknown bowel disease status. Six patients (3 with prior diagnosis of CD, 3 without) had absence of bowel enhancement on both ultrasound and MRI. Eleven patients with findings of inflammation and enhancement on MRI also had concurrent evidence of enhancement on CEUS. Three patients who had no evidence of inflammation on MRI, with known CD, had prominent bowel enhancement on CEUS. One patient with known colitis, whom we enrolled to evaluate for small bowel disease, had no evidence on either MRI or CEUS, however CEUS showed significant fat stranding around the colon, supporting the diagnosis of CD. CONCLUSIONS: The sensitivity of CEUS to detect bowel inflammation when seen on MRI was 100%. In addition, CEUS may also have the ability to detect bowel inflammation, even in the presence of a normal MRI.

Vitamin D: a brief overview of its importance and role in inflammatory bowel disease.

Vitamin D has traditionally been known for its regulation of bone metabolism and homeostasis, but emerging evidence suggests that it also has a broad function in immune regulation, and inflammatory bowel disease (IBD). The etiology of IBD is thought to be multifactorial but stems in part due to the deregulation of the immune response to environmental factors in the setting of a pre-existing genetic disposition. Vitamin D, based on its mechanistic role at the cellular level in T-cell trafficking, had been postulated to have a direct effect on the immune system, This alludes to the fact that vitamin D may have the ability to not only potentiate the IBD phenotype, but also in doing so, its supplementation may serve a therapeutic role in amelioration of the diseased state. We review in this article the current literature as it pertains to the basic mechanism of Vitamin D, its role in the pathogenicity of IBD, how it regulates our immune system, interpretation and accuracy of obtaining levels, and the role there may be in supplementation in IBD.

Outcome of tacrolimus and vedolizumab after corticosteroid and anti-TNF failure in paediatric severe colitis.

BACKGROUND: Severe colitis flare from ulcerative colitis (UC) or Crohn's disease (CD) may be refractory to corticosteroids and antitumour necrosis factor (TNF) agents resulting in high colectomy rates. We aimed to describe the utility of tacrolimus to prevent colectomy during second-line vedolizumab initiation after corticosteroid and anti-TNF treatment failure in paediatric severe colitis. METHODS: A retrospective cohort analysis was performed between 1 October 2014 and 31 October 2016 at a single tertiary care centre. Inclusion criteria were patients with severe colitis who received tacrolimus before or during vedolizumab induction and previous exposure to anti-TNF therapy with or without corticosteroids. The initiation of tacrolimus was clinician dependent based on an institutional protocol. RESULTS: Twelve patients (10 UC, two CD; median age 16 years; three female) received at least one dose of vedolizumab 10 mg/kg (max of 300 mg) due to anti-TNF therapy failure and persistent flare not responsive to corticosteroids. Of the 12 patients, eight (67%) and four (33%) had failed one or two anti-TNF agents, respectively. Tacrolimus was initiated for acute disease severity during hospitalisation (58%) or ongoing flare during outpatient care (42%). 9 (75%) of 12 patients avoided colectomy or inflammatory bowel disease-related surgery at 24 weeks and eight (68%) continued on vedolizumab maintenance with no adverse events out to 80 weeks. CONCLUSION: We report real-world data on the outcome of tacrolimus around vedolizumab initiation in paediatric UC or CD after corticosteroid and anti-TNF therapy treatment failure. Our pilot experience indicates a potential benefit of concomitant tacrolimus when initiating vedolizumab therapy.

Histologic Features of Gastrointestinal Tract Biopsies in IgA Vasculitis (Henoch-Schönlein Purpura).

Immunoglobulin A (IgA) vasculitis or Henoch-Schönlein purpura (HSP) typically occurs in the pediatric population, although rare cases also occur in adults. Gastrointestinal (GI) involvement is common. The "classic" histologic finding in IgA vasculitis (HSP) is leukocytoclastic vasculitis (LCV); other histologic features in biopsies of IgA vasculitis (HSP) have only been rarely described. The pathology archival files at our institution were searched for GI biopsies from patients with IgA vasculitis (HSP). Slides were retrieved and histologic and clinical features were reviewed. We identified 16 patients with IgA vasculitis (HSP) with a GI biopsy series, including both adult and pediatric patients. The most common histologic abnormality was lamina propria hemorrhage (all cases) with many cases also showing lamina propria fibrin deposition with red cell sludging and nuclear debris (7 cases). Twelve of the 16 duodenal biopsies had acute duodenitis; 3 of which were severe and erosive. Several also had an eosinophilic infiltrate. Seven of the 9 jejunal and/or ileal biopsies had acute jejunitis or ileitis. An acute colitis or proctitis was observed in 9/12 colorectal biopsies. Four biopsies contained LCV; in each of these cases, the involved vessels were small capillaries within the lamina propria. Only 1 biopsy contained deeper submucosal vessels, but they were uninvolved. Sites involved by LCV included the colorectum (2 cases), colorectum and terminal ileum, terminal ileum only, duodenum, and jejunum (1 case each). All patients presented with abdominal pain; 13/16 developed a rash, 1 following the index biopsy. Other presenting symptoms included diarrhea and/or hematochezia (8 cases), nausea/vomiting (5 cases), and intussusception (1 case). Four patients had concurrent skin biopsies showing LCV; only 1 of these patients had LCV on GI biopsy. Indications for biopsy included nonspecific presenting symptoms, absence of rash at presentation, and/or failure to respond adequately to steroid therapy. Biopsies are commonly performed in patients with or without suspected IgA vasculitis (HSP) to rule out infection, inflammatory bowel disease, and less commonly, vasculitis. In general, vasculitis is not commonly observed in GI biopsies of patients with IgA vasculitis (HSP), and the spectrum of findings includes neutrophilic infiltrate within the small bowel and colon, with the duodenum most commonly affected. While the clinical and histologic findings may mimic early inflammatory bowel disease, the presence of predominant small bowel involvement, especially erosive duodenitis, should raise suspicion for IgA vasculitis (HSP). Biopsies should be obtained before steroid therapy is initiated, if possible.

A Mobile Infliximab Dosing Calculator for Therapy Optimization in Inflammatory Bowel Disease.

Background: Inadequate infliximab (IFX) drug exposure remains a clinical challenge and leads to high loss of response rates and therapy failure in inflammatory bowel disease (IBD). We aimed to determine the feasibility and pilot effectiveness of a novel, web-based, mobile IFX dosing calculator (mIDC) for therapy optimization. Methods: We developed an mIDC leveraging the known clinical variables of C-reative protein (CRP), albumin, patient's weight, disease activity indices, calprotectin, drug trough levels, and antibodies to IFX that significantly affect pharmacokinetics and/or outcomes. A prospective observational cohort study in pediatric and young adult IBD patients receiving maintenance IFX was performed. System-wide practice adoption of mIDC was achieved through a quality improvement (QI) initiative within a hospital-based infusion unit. Results: Forty-nine patients (median age: 16.0 years; 55% female; 65% Crohn's disease) were followed over 9 months. mIDC recommendations for dose optimization were followed by the treating physicians in 198 (89%) out of 222 infusions. Twenty-eight (13%) of 222 mIDC recommendations were to escalate IFX dosing; 15 (54%) of 28 escalation recommendations were declined, and these patients were more likely to already be receiving IFX dose intensification compared with those in whom escalation recommendations were followed (P < 0.05). From mIDC initiation to end of follow-up, mean albumin levels remained unchanged at 3.8 g/dL. Median CRP remained unchanged at 2 g/L. Median calprotectin levels showed a downward trend from 30 to 27 µg/g (n = 9, P < 0.05). The percentage of patients undergoing therapeutic drug monitoring in clinical care increased from 34% to 86% with the QI initiative. The target median IFX trough goal of >5 µg/mL was achieved with 81% probability throughout the QI initiative, an increase of 12% compared with pre-QI values. Conclusions: The use of a novel mIDC is feasible and potentially effective, facilitating both standardization and individualization of therapy in clinical care. mIDC appears to be a practical IFX dosing tool for point-of-care use, leveraging individual pharmacokinetic considerations.

Role of imaging in the evaluation of inflammatory bowel disease: How much is too much?

Inflammatory bowel disease (IBD) is a lifelong condition with waxing and waning disease course that requires reassessment of disease status as well as screening for complications throughout a patient's lifetime. Laboratory testing, endoscopic assessment, and fecal biomarkers are often used in the initial diagnosis and ongoing monitoring of a patient with IBD. Imaging plays an integral role in the diagnosis and evaluation of IBD. Different imaging modalities can be used over the course of a patient's lifetime, from the initial screening and diagnosis of IBD, to determining the extent of intestinal involvement, monitoring for disease activity, and evaluating for complications of uncontrolled IBD. The various imaging modalities available to the provider each have a unique set of risks and benefits when considering cost, radiation exposure, need for anesthesia, and image quality. In this article we review the imaging techniques available for the evaluation of IBD including fluoroscopic small bowel follow-through, computed tomography enterography, magnetic resonance enterography, and transabdominal ultrasound with particular focus on the judicious use of imaging and the risks and benefits of each option. We also review the risks of ionizing radiation, strategies to reduce exposure to ionizing radiation, and current imaging guidelines among pediatric and adult patient with IBD.

Out-of-pocket Cost Burden in Pediatric Inflammatory Bowel Disease: A Cross-sectional Cohort Analysis.

BACKGROUND: Pediatric inflammatory bowel disease (IBD), consisting of Crohn's disease (CD) and ulcerative colitis (UC), can result in significant morbidity requiring frequent health care utilization. Although it is known that the overall financial impact of pediatric IBD is significant, the direct out-of-pocket (OOP) cost burden on the parents of children with IBD has not been explored. We hypothesized that affected children with a more relapsing disease course and families in lower income strata, ineligible for need-based assistance programs, disparately absorb ongoing financial stress. METHODS: We completed a cross-sectional analysis among parents of children with IBD residing in California using an online HIPAA-secure Qualtrics survey. Multicenter recruitment occurred between December 4, 2013 and September 18, 2014 at the point-of-care from site investigators, informational flyers distributed at regional CCFA conferences, and social media campaigns equally targeting Northern, Central, and Southern California. IBD-, patient-, and family-specific information were collected from the parents of pediatric patients with IBD patients younger than 18 years of age at time of study, carry a confirmed diagnosis of CD or UC, reside in and receive pediatric gastroenterology care in California, and do not have other chronic diseases requiring ongoing medical care. RESULTS: We collected 150 unique surveys from parents of children with IBD (67 CD; 83 UC). The median patient age was 14 years for both CD and UC, with an overall 3.7 years (SD 2.8 yr) difference between survey completion and time of IBD diagnosis. Annually, 63.6%, 28.6%, and 5.3% of families had an OOP cost burden >$500, >$1000, and >5000, respectively. Approximately one-third (36.0%) of patients had emergency department (ED) visits over the past year, with 59.2% of these patients spending >$500 on emergency department copays, including 11.1% who spent >$5000. Although 43.3% contributed <$500 on procedure and test costs, 20.0% spent >$2000 in the past year. Families with household income between $50,000 and $100,000 had a statistically significant probability (80.6%) of higher annual OOP costs than families with lower income <$50,000 (20.0%; P < 0.0001) or higher income >$100,000 (64.6%; P < 0.05). Multivariate analysis revealed that clinical variables associated with uncontrolled IBD states correlated to higher OOP cost burden. Annual OOP costs were more likely to be >$500 among patients who had increased spending on procedures and tests (odds ratio [OR], 5.63; 95% confidence interval [CI], 2.73-11.63), prednisone course required over the past year (OR, 3.19; 95% CI, 1.02-9.92), at least 1 emergency department visit for IBD symptoms (OR, 2.84; 95% CI, 1.33-6.06), at least 4 or more outpatient primary medical doctor visits for IBD symptoms (OR, 2.82; 95% CI, 1.40-5.68), and history of 4 or more lifetime hospitalizations for acute IBD care (OR, 2.60; 95% CI, 1.13-5.96). CONCLUSIONS: Previously undocumented, a high proportion of pediatric IBD families incur substantial OOP cost burden. Patients who are frequently in relapsing and uncontrolled IBD states require more acute care services and sustain higher OOP cost burden. Lower middle income parents of children with IBD ineligible for need-based assistance may be particularly at risk for financial stress from OOP costs related to ongoing medical care.

Association between lichen sclerosus and celiac disease: a report of three pediatric cases.

The prevalence of celiac disease (CD) is increasing and may be as high as 1% of the US population. The typical presentation of CD generally includes gastrointestinal symptoms, but more individuals are presenting with extraintestinal manifestations. A wide variety of dermatologic associations have been described with CD, including alopecia, dermatitis herpetiformis, and enamel hypoplasia. In this report we describe three girls with CD who presented with hypopigmented skin lesions and pruritus in the perivaginal and perianal areas, consistent with the diagnosis of lichen sclerosus (LS). All three presented within 1 year to the same practitioner. To our knowledge, this association has not previously been explored in the literature. These cases elucidate a possible relationship between CD and LS.

Utilization trends of anti-TNF agents and health outcomes in adults and children with inflammatory bowel diseases: a single-center experience.

BACKGROUND: Utilization trends and health effects of infliximab and adalimumab in inflammatory bowel disease (IBD) are incompletely understood. We aimed to describe utilization trends of these 2 anti-tumor necrosis factor (TNF) agents, determine the correlation between utilization with rates of hospitalization and surgery and describe differences in use between adults and children. METHODS: Longitudinal data were analyzed for drug utilization, hospitalization, and abdominal surgery. Descriptive statistics were used to show trends, and utilization quotients were compared for standardization. Multivariate logistic regression analysis assessed the association between drug use and rates of hospitalization and surgery. RESULTS: Four hundred thirty-eight pediatric and 2514 adult patients with IBD generated a total of 51,882 inpatient and outpatient encounters, representing 1185 Crohn's disease, 1531 ulcerative colitis, and 236 indeterminate colitis patients. From 2007 through 2012, utilization quotients declined for hospitalization but remained unchanged for surgery; adalimumab saw a 3-fold increase, despite continued dominance of infliximab. Median band and mean fitted plots showed downward hospitalization trends from 2006 to 2012. Utilization of infliximab peaked in 2008, Q4 with gradual decline to 2012, Q2; and adalimumab showed moderate increased utilization since 2007, Q1. Use of infliximab (odds ratio [OR], 0.76; 95% confidence interval [CI], 0.70-0.83) and adalimumab (OR, 0.79; 95% CI, 0.72-0.87) was associated with decreased hospitalization risk but not associated with reduced abdominal surgery risk. Children had increased hospitalization (OR, 2.68; 95% CI, 2.49-2.88) but decreased risk for abdominal surgery (OR, 0.57; 95% CI, 0.46-0.70). CONCLUSIONS: Current infliximab use remains substantially greater than adalimumab use, despite recent increased use of adalimumab. Although trends for hospitalization for IBD are decreasing, it is not reflected in abdominal surgery rates in a tertiary IBD referral center.

Cost-effectiveness of universal serologic screening to prevent nontraumatic hip and vertebral fractures in patients with celiac disease.

BACKGROUND & AIMS: Patients with asymptomatic or poorly managed celiac disease can experience bone loss, placing them at risk for hip and vertebral fractures. We analyzed the cost-effectiveness of universal serologic screening (USS) vs symptomatic at-risk screening (SAS) strategies for celiac disease because of the risk of nontraumatic hip and vertebral fractures if untreated or undiagnosed. METHODS: We developed a lifetime Markov model of the screening strategies, each with male or female cohorts of 1000 patients who were 12 years old when screening began. We screened serum samples for levels of immunoglobulin A, compared with tissue transglutaminase and total immunoglobulin A, and findings were confirmed by mucosal biopsy. Transition probabilities and quality of life estimates were obtained from the literature. We used generalizable cost estimates and Medicare reimbursement rates and ran deterministic and probabilistic sensitivity analyses. RESULTS: For men, the average lifetime costs were $8532 and $8472 for USS and SAS strategies, respectively, corresponding to average quality-adjusted life year gains of 25.511 and 25.515. Similarly for women, costs were $11,383 and $11,328 for USS and SAS strategies, respectively, corresponding to quality-adjusted life year gains of 25.74 and 25.75. Compared with the current standard of care (SAS), USS produced higher average lifetime costs and lower quality of life for each sex. Deterministic and probabilistic sensitivity analyses showed that the model was robust to realistic changes in all the variables, making USS cost-ineffective on the basis of these outcomes. CONCLUSIONS: USS and SAS are similar in lifetime costs and quality of life, although the current SAS strategy was overall more cost-effective in preventing bone loss and fractures among patients with undiagnosed or subclinical disease. On the basis of best available supportive evidence, it is more cost-effective to maintain the standard celiac screening practices, although future robust population-based evidence in other health outcomes could be leveraged to reevaluate current screening guidelines.

Cost-effectiveness of early colectomy with ileal pouch-anal anastamosis versus standard medical therapy in severe ulcerative colitis.

BACKGROUND: Inflammatory bowel diseases are costly chronic gastrointestinal diseases. We aimed to determine whether immediate colectomy with ileal pouch-anal anastamosis (IPAA) after diagnosis of severe ulcerative colitis (UC) was cost-effective compared to the standard medical therapy. METHODS: We created a Markov model simulating 2 cohorts of 21-year-old patients with severe UC, following them until 100 years of age or death, comparing early colectomy with IPAA strategy to the standard medical therapy strategy. Deterministic and probabilistic analyses were performed. RESULTS: Standard medical care accrued a discounted lifetime cost of $236,370 per patient. In contrast, early colectomy with IPAA accrued a discounted lifetime cost of $147,763 per patient. Lifetime quality-adjusted life-years gained (QALY-gained) for standard medical therapy was 20.78, while QALY-gained for early colectomy with IPAA was 20.72. The resulting incremental cost-effectiveness ratio (Δcosts/ΔQALY) was approximately $1.5 million per QALY-gained. Results were robust to one-way sensitivity analyses for all variables in the model. Quality-of-life after colectomy with IPAA was the most sensitive variable impacting cost-effectiveness. A low utility value of less than 0.7 after colectomy with IPAA was necessary for the colectomy with IPAA strategy to be cost-ineffective. CONCLUSIONS: Under the appropriate clinical settings, early colectomy with IPAA after diagnosis of severe UC reduces health care expenditures and provides comparable quality of life compared to exhaustive standard medical therapy.

Immunophenotyping of peripheral eosinophils demonstrates activation in eosinophilic esophagitis.

BACKGROUND AND AIM: Eosinophilic esophagitis (EoE) is a chronic inflammatory disorder characterized by upper gastrointestinal symptoms and the presence of high numbers of eosinophils in the esophagus. Although eosinophils in the esophagus have been found to be activated in subjects with EoE, detailed studies of intracellular signaling pathways involved in the mechanism of activation of eosinophils in EoE have heretofore been limited. The aim of the study was to assess whether any surface molecules or transcription factors are activated in peripheral eosinophils in subjects with EoE. METHODS: Eosinophils and CD3+ lymphocytes were identified directly from 50 µL of whole blood of EoE and control subjects. Using Hi-FACS, levels of surface activation markers, including CD66b, and intracellular phosphoepitopes, including phosphorylated forms of signal transducer and activator of transcription (phospho-STAT) 1 and 6, were measured within each cell subset. RESULTS: Levels of surface CD66b as well as levels of intracellular phospho-STAT1 and phospho-STAT6 in peripheral blood eosinophils were significantly higher for untreated subjects with EoE vs healthy controls (P < 0.05). Levels of phospho-STAT1 and phospho-STAT6 in peripheral blood eosinophils were lower in subjects with EoE on therapy versus untreated subjects with EoE (P < 0.05). CONCLUSIONS: Levels of phospho-STAT1 and phospho-STAT6, transcription factors involved in inflammatory processes, were both significantly higher in peripheral eosinophils from untreated (ie, newly diagnosed) subjects with EoE versus subjects with EoE on therapy, healthy controls. Blood-based measurements of CD66b and phospho-STAT levels in peripheral eosinophils may be beneficial for identifying EoE.