Peripheral Eosinophilia in Patients With Inflammatory Bowel Disease Defines an Aggressive Disease Phenotype

Eosinophils, Eosinophilic Gastrointestinal Diseases, and Inflammatory Bowel Disease: A Critical Review

BACKGROUND/OBJECTIVES

Inflammatory bowel disease (IBD) and eosinophilic gastrointestinal diseases (EGIDs) are complex, multifactorial chronic inflammatory disorders affecting the gastrointestinal tract. Their epidemiology, particularly for eosinophilic esophagitis (EoE), is increasing worldwide, with a rise in the co-diagnosis of IBD and EGIDs. Both disorders share common risk factors, such as early exposure to antibiotics or specific dietary habits. Moreover, from a molecular perspective, eosinophilic infiltration is crucial in the diagnosis of eosinophilic disorders, and it also plays a pivotal role in IBD histological diagnosis. Indeed, recent evidence highlights the significant role of eosinophils in the health of the intestinal mucosal barrier and as mediators between innate and acquired immunity, even indicating a potential role in IBD pathogenesis. This narrative review aims to summarize the current evidence regarding the common clinical and molecular aspects of EGIDs and IBD and the current state of knowledge regarding overlap conditions and their pathogenesis.

METHODS

Pubmed was searched until May 2023 to assess relevant studies describing the epidemiology, pathophysiology, and therapy of EGIDs in IBD.

RESULTS

The immune pathways and mechanisms underlying both EGIDs and IBD remain partially known. An improved understanding of the role of eosinophils in overlapping conditions could lead to enhanced diagnostic precision, the development of more effective future therapeutic strategies, and a more accurate prediction of patient response. Consequently, the identification of red flags indicative of an eosinophilic disorder in IBD patients is of paramount importance and must be evaluated on a case-by-case basis.

Role of peripheral and tissue eosinophils and eosinophil cationic protein in pediatric inflammatory bowel disease

OBJECTIVES

Inflammatory bowel disease (IBD), eosinophilic gastrointestinal disease (EGID), and functional abdominal pain disorder (FAPD) present with nonspecific gastrointestinal (GI) symptoms clinically and also have some similarities in pathogeneses associated with eosinophils. Therefore, we aimed to evaluate the role of eosinophils in IBD compared to EGID and FAPD by investigating eosinophils in peripheral blood and GI tissue and eosinophil cationic protein (ECP).

METHODS

Pediatric patients with chronic GI symptoms who underwent endoscopic biopsies were enrolled. Complete blood cell counts, inflammatory markers, immunoglobulin E (IgE), serum ECP levels, and endoscopic and histopathologic findings were retrospectively reviewed.

RESULTS

A total of 387 patients were included: 179 with EGID, 107 with IBDs, and 82 with FAPD. Peripheral absolute eosinophil count (AEC), total IgE, and serum ECP were significantly higher in both IBD and EGID than in FAPD (all p < 0.05). Statistically significant differences were noted among the three groups in tissue eosinophil counts in each segment of GI tract except for the esophagus (p < 0.05). Significant differences were observed in tissue eosinophil counts in the ascending, sigmoid colon, and rectum between EGID and IBD (p < 0.05). Peripheral and tissue eosinophils in the stomach and duodenum revealed positive correlation in both EGID and IBD (both p < 0.001).

CONCLUSION

Elevated eosinophil-related markers, as well as increased tissue eosinophilic infiltration in the affected areas of the GI tract in both IBD and EGID compared to FAPD, suggest that eosinophils might play a common important role in the pathogeneses of both diseases.

Hypereosinophilic Syndrome with Pulmonary Involvement in Ulcerative Colitis

Reactive eosinophilia is associated with inflammatory bowel disease and is more common in patients with ulcerative colitis (UC) compared with Crohn's disease. The prevalence rate of peripheral blood eosinophilia in patients with inflammatory bowel disease has been described to be as high as 30%-40% of patients in a pediatric study. The coexistence of hypereosinophilic syndrome (HES) and UC is uncommon. We present a 15-year-old boy with UC associated with HES who presented with chest pain and shortness of breath. Laboratory evaluation showed marked eosinophilia. Alternative causes of eosinophilia including eosinophilic leukemia, infections, or drug-induced eosinophilic pneumonia were ruled out. The patient was ultimately diagnosed with HES responsive to mepolizumab.

Peripheral Blood Monocytosis Is Associated With Long-Term Disease Severity in Pediatric-Onset Inflammatory Bowel Disease

OBJECTIVES

Peripheral blood monocytosis (PBM) is a marker of increased disease severity in adults with inflammatory bowel diseases (IBDs). We sought to determine whether PBM serves as a prognostic biomarker in patients with pediatric-onset IBD for a more aggressive long-term disease course when followed into adulthood.

METHODS

Patients with pediatric-onset inflammatory bowel disease were identified within an adult tertiary care center, within a consented, prospectively collected natural history disease registry, to compare clinical outcomes between patients with and without PBM from the years 2009 to 2019. Patients demonstrating elevation in PBM at any time defined membership and long-term clinical trajectories were compared with pediatric-onset patients without PBM.

RESULTS

A total of 581 patients with IBD, diagnosed by 18 years of age, were identified for inclusion, of which 440 patients were diagnosed with Crohn disease and 141 with ulcerative colitis. Monocytosis was detected by complete blood cell counts in 40.1% of patients. PBM was associated with steroid and biologic exposure, number of IBD-related surgeries, and increased health care utilization. Multivariate logistic regression analyses, accounting for elevation of inflammatory markers and other values associated with acute disease activity as well as steroid use, showed persistently increased odds of biologic exposure, emergency department visits, and hospitalizations, but not surgeries, after detection of monocytosis.

CONCLUSIONS

Within patients with pediatric-onset IBD, the sub-cohort with PBM had associated worse clinical outcomes and other markers of increased disease severity.

French guidelines for the etiological workup of eosinophilia and the management of hypereosinophilic syndromes

Eosinophilic-related clinical manifestations are protean and the underlying conditions underpinning eosinophilia are highly diverse. The etiological workup of unexplained eosinophilia/hypereosinophilia can be challenging, and can lead sometimes to extensive, inappropriate, costly and/or invasive investigations. To date, guidelines for the etiological workup and management of eosinophilia are mainly issued by hematologists, and thus mostly cover the scope of clonal hypereosinophilic syndromes (HES). Here, thanks to an extensive literature review, and thanks to the joint work of a large panel of experts involving physicians from both adult and pediatric medicine and from various subspecialties (as well as a representative of a patients' association representative), we provide recommendations for both the step-by step diagnostic workup of eosinophilia (whether unexplained or within specific contexts) as well as the management and follow-up of the full spectrum of eosinophilic disorders (including clonal, reactive, lymphocytic and idiopathic HES, as well as single-organ diseases). Didactic prescription summaries intended to facilitate the prescription of eosinophil-targeted drugs are also provided, as are practical diagnostic and therapeutic algorithms. Lastly, this set of recommendations also includes a summary intended for general practitioners, as well as an overview of the therapeutic patient education program set up by the French reference center for HES. Further updates will be mandatory as new validated information emerges.

Prognostic Value of Colonic Tissue and Blood Eosinophils in Ulcerative Colitis

BACKGROUND

It has been suggested that eosinophils may be a prognostic marker of disease outcome in ulcerative colitis (UC), but conflicting data exist. The objective was to investigate the extent of mucosal eosinophils and peripheral blood eosinophil count in newly diagnosed UC patients and to investigate its predictive value in short- and long-term disease outcomes.

METHODS

The degree of eosinophilia in baseline colonic biopsies and blood of newly diagnosed UC patients was retrospectively analyzed. It was investigated if tissue and blood eosinophilia could be a marker of a severe phenotype of UC, defined as the need for corticosteroids or immunomodulators in the first year or treatment with therapeutic monoclonal antibodies or colectomy during follow-up. Time to therapeutic monoclonal antibodies and time to colectomy were also evaluated as outcomes.

RESULTS

There were 103 UC patients (median age 26 years) included. Median tissue peak eosinophil count (PEC) was 70.0 and median peripheral blood eosinophil count was 0.3 × 109/L at diagnosis. Tissue PEC (r = -0.161, P = .104) and blood eosinophil count (r = 0.022, P = .877) were not correlated with the severity of histologic inflammation. Logistic regression analyses did not identify PEC and blood eosinophil count as predictors of more severe disease outcomes. Tissue PEC and peripheral blood eosinophil count did not predict the time the initiation of therapeutic monoclonal antibodies or colectomy.

CONCLUSION

Baseline tissue or peripheral blood eosinophils are not markers of disease activity and cannot be used as a predictor of severe disease outcomes in both adults and children with UC.

Resolved Hypereosinophilic Syndrome and Immune Thrombocytopenic Purpura in Ulcerative Colitis Patients Post Colectomy: A Case Series and Literature Review

Introduction

Hypereosinophilic syndrome (HES) and immune thrombocytopenic purpura (ITP) have been reported to co-occur with ulcerative colitis (UC). However, the exact pathogenic mechanisms of their occurrence remain elusive. In this article, we aim to describe two cases of UC patients who developed refractory HES and ITP and elaborate on their potential pathogenesis.

Case Study

We report two middle-aged patients diagnosed with UC. The first patient developed HES that was refractory to conventional medical therapy of idiopathic HES, and the second developed refractory ITP that failed steroid and immunosuppressive therapy. Both conditions improved considerably following colectomy, suggesting they are of a reactive rather than idiopathic nature.

Conclusion

In patients with UC and refractory comorbid HES or ITP, the reactive nature of these comorbidities should be taken into consideration, and colectomy, therefore, should be considered if clinically indicated.

Longitudinal multi-omics analysis identifies early blood-based predictors of anti-TNF therapy response in inflammatory bowel disease

Background and aims

Treatment with tumor necrosis factor α (TNFα) antagonists in IBD patients suffers from primary non-response rates of up to 40%. Biomarkers for early prediction of therapy success are missing. We investigated the dynamics of gene expression and DNA methylation in blood samples of IBD patients treated with the TNF antagonist infliximab and analyzed the predictive potential regarding therapy outcome.

Methods

We performed a longitudinal, blood-based multi-omics study in two prospective IBD patient cohorts receiving first-time infliximab therapy (discovery: 14 patients, replication: 23 patients). Samples were collected at up to 7 time points (from baseline to 14 weeks after therapy induction). RNA-sequencing and genome-wide DNA methylation data were analyzed and correlated with clinical remission at week 14 as a primary endpoint.

Results

We found no consistent ex ante predictive signature across the two cohorts. Longitudinally upregulated transcripts in the non-remitter group comprised TH2- and eosinophil-related genes including ALOX15, FCER1A, and OLIG2. Network construction identified transcript modules that were coherently expressed at baseline and in non-remitting patients but were disrupted at early time points in remitting patients. These modules reflected processes such as interferon signaling, erythropoiesis, and platelet aggregation. DNA methylation analysis identified remission-specific temporal changes, which partially overlapped with transcriptomic signals. Machine learning approaches identified features from differentially expressed genes cis-linked to DNA methylation changes at week 2 as a robust predictor of therapy outcome at week 14, which was validated in a publicly available dataset of 20 infliximab-treated CD patients.

Conclusions

Integrative multi-omics analysis reveals early shifts of gene expression and DNA methylation as predictors for efficient response to anti-TNF treatment. Lack of such signatures might be used to identify patients with IBD unlikely to benefit from TNF antagonists at an early time point.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13073-022-01112-z.

Proinflammatory role of basophils in oxazolone-induced chronic intestinal inflammation

BACKGROUND AND AIM

The functions of basophils have not been elucidated until recently because of their rarity. However, with recent developments in basophil-specific antibodies and basophil-deficient animals, the roles of basophils in various diseases related to chronic inflammation have been clarified. In this study, we aimed to investigate the roles of basophils in human ulcerative colitis (UC) and oxazolone (OXA) colitis using genetically engineered Mcpt8^DTR mice.

METHODS

Immunohistochemical staining of human colon specimens was performed to examine the involvement of basophils in the pathogenesis of UC. We examined the correlation between the number of infiltrating basophils and the UC endoscopic index of severity (UCEIS), Mayo score, and Matts score. We also examined the correlation between eosinophil count and basophil infiltration. In murine experiments, we examined whether basophil infiltration was involved in OXA-induced colitis and whether basophil depletion improved inflammation in Mcpt8^DTR mice.

RESULTS

Colonic basophil infiltration was significantly increased in patients with UC. There were significant correlations between UCEIS, Mayo score, Matts score, and the number of infiltrating basophils. In murine OXA-induced colitis, a significant increase in basophil infiltration was observed. When basophils were depleted by diphtheria toxin in Mcpt8^DTR mice, inflammation improved significantly and mRNA expression of some proinflammatory cytokines, including Tnf-α and Ifn-γ decreased significantly.

CONCLUSION

Basophil infiltration correlated with endoscopic, clinical, and pathological scores in human UC independently of eosinophil infiltration, and depletion of basophils ameliorated mucosal inflammation in murine OXA-induced colitis, collectively suggesting that basophils exert a proinflammatory role in chronic intestinal inflammation such as UC.

The Clinical Significance of Eosinophils in Ulcerative Colitis: A Systematic Review

BACKGROUND AND AIMS

Ulcerative colitis [UC] is characterised by an unpredictable disease course and variable response to therapy. Recent studies suggest a role for eosinophils in both pathogenesis and predicting treatment response. The goal of this study was to determine the association between eosinophils and clinical outcomes in UC.

METHODS

A systematic review of the literature from database inception to May 2021 was performed to identify all studies evaluating the relationship between eosinophils and/or eosinophil-derived proteins [EDPs] and clinical outcomes, such as disease activity, clinical relapse, severity of disease, and response to treatment.

RESULTS

A total of 55 studies were identified. Of these, 34 studies evaluated the relationship between eosinophils in colonic tissue and outcomes and 15 in blood. Eighteen studies assessed the relationship between EDPs and outcomes. In 25 of 34 studies, a positive correlation between eosinophils and/or EDPs and disease activity was reported, three studies found a negative correlation, and nine studies found no correlation. Positive correlations between eosinophils and clinical relapse were shown in four of nine studies, and with disease outcome severity in five of seven studies. Four of 15 studies showed that subjects with higher eosinophil levels had a poor response to treatment.

CONCLUSIONS

These findings suggest that higher eosinophil levels may be associated with increased disease activity and poorer clinical outcomes and response to therapy. Future studies are needed to determine whether a distinct eosinophil-rich UC phenotype exists and whether eosinophil-targeted therapy can alter the disease course.

Case report: Eosinophilic pneumonia associated with vedolizumab therapy in a patient with ulcerative colitis

Extraintestinal manifestations are common in patients with inflammatory bowel disease, while respiratory involvement is less common. Vedolizumab is a new class of anti-integrin biological agents approved for treating inflammatory bowel disease. In this report, we present the case of a 38-year-old patient with ulcerative colitis for 7 years who developed cough, fever, and pulmonary infiltrates after taking vedolizumab. There was a spontaneous improvement in clinical symptoms and radiological abnormalities after discontinuing vedolizumab and introducing steroids. Despite the rarity of vedolizumab-induced eosinophilic pneumonia, the case reports indicate that patients with unexplained respiratory symptoms that are taking vedolizumab should be fully contemplated.

Mucosal Eosinophil Abundance in Non-Inflamed Colonic Tissue Is Associated with Response to Vedolizumab Induction Therapy in Inflammatory Bowel Disease

Vedolizumab is used as a treatment for patients with inflammatory bowel disease (IBD), but induction therapy leads to clinical response and remission in approximately 55% and 30% of patients with IBD, respectively. In this study, we aimed to explore the predictive value of mucosal eosinophils and serum eotaxin-1 regarding response to vedolizumab induction therapy. Eighty-four (84) patients with IBD (37 Crohn’s disease [CD], 47 ulcerative colitis [UC]) were included. For 24 patients with IBD, histopathology was assessed for eosinophil counts in non-inflamed colonic tissue prior to vedolizumab treatment. For 64 patients with IBD, serum eotaxin-1 levels were quantified prior to (baseline) and during vedolizumab treatment. Serum samples of 100 patients with IBD (34 CD, 66 UC) from the GEMINI 1 and 2 trials were used for external validation. Baseline mucosal eosinophil numbers in non-inflamed colonic tissue were significantly higher in responders to vedolizumab induction therapy when compared to primary non-responders (69 [34−138] vs. 24 [18−28] eosinophils/high-power field, respectively, p < 0.01). Baseline serum eotaxin-1 levels in the discovery cohort were significantly elevated in responders, compared to primary non-responders (0.33 [0.23−0.44] vs. 0.20 [0.16−0.29] ng/mL, p < 0.01). Prediction models based on mucosal eosinophil counts and serum eotaxin-1 showed an area under the curve (AUC) of 0.90 and 0.79, respectively. However, the predictive capacity of baseline serum eotaxin-1 levels could not be validated in the GEMINI cohort. Mucosal eosinophil abundance in non-inflamed colonic tissue was associated with response to vedolizumab induction therapy in patients with IBD. Future studies are warranted to further validate the potential value of mucosal eosinophils and serum eotaxin-1 as biomarkers for response to vedolizumab therapy.

Utilizing Deep Learning to Analyze Whole Slide Images of Colonic Biopsies for Associations Between Eosinophil Density and Clinicopathologic Features in Active Ulcerative Colitis

BACKGROUND

Eosinophils have been implicated in the pathogenesis of ulcerative colitis and have been associated with disease course and therapeutic response. However, associations between eosinophil density, histologic activity, and clinical features have not been rigorously studied.

METHODS

A deep learning algorithm was trained to identify eosinophils in colonic biopsies and validated against pathologists' interpretations. The algorithm was applied to sigmoid colon biopsies from a cross-sectional cohort of 88 ulcerative colitis patients with histologically active disease as measured by the Geboes score and Robarts histopathology index (RHI). Associations between eosinophil density, histologic activity, and clinical features were determined.

RESULTS

The eosinophil deep learning algorithm demonstrated almost perfect agreement with manual eosinophil counts determined by 4 pathologists (interclass correlation coefficients: 0.805-0.917). Eosinophil density varied widely across patients (median 113.5 cells per mm2, interquartile range 108.9). There was no association between eosinophil density and RHI (P = 0.5). Significant differences in eosinophil density were seen between patients with Montreal E3 vs E2 disease (146.2 cells per mm2 vs 88.2 cells per mm2, P = 0.005). Patients on corticosteroids had significantly lower eosinophil density (62.9 cells per mm2 vs 124.1 cells per mm2, P = 0.006). No association between eosinophil density and biologic use was observed (P = 0.5).

CONCLUSIONS

We developed a deep learning algorithm to quantify eosinophils in colonic biopsies. Eosinophil density did not correlate with histologic activity but did correlate with disease extent and corticosteroid use. Future studies applying this algorithm in larger cohorts with longitudinal follow-up are needed to further elucidate the role of eosinophils in ulcerative colitis.

Collecting New Peak and Intermediate Infliximab Levels to Predict Remission in Inflammatory Bowel Diseases

BACKGROUND

The loss of response to infliximab is a challenge for clinicians in the management of inflammatory bowel disease (IBD). Mounting evidence suggests that therapeutic drug monitoring at induction may predict remission during maintenance. The aim of the study was to improve predictive models of remission by exploring new peak and intermediate infliximab measurements during induction.

METHODS

This was a prospective multicenter study evaluating the pharmacokinetics of infliximab during induction in a pioneer cohort of 63 patients with IBD. Pharmacokinetics data including peak, intermediate, and trough levels were combined with clinical and biological parameters and were subsequently fed into tailored logistic regression and tree-based techniques to predict remission at week 30.

RESULTS

Infliximab peak levels at week 2, intermediate levels at week 3, and trough levels at week 6 were correlated with remission at week 30. Predictive models exhibited an increased accuracy over the successive timepoints of the induction with key inputs such as albumin, C-reactive protein, eosinophils, neutrophils, lymphocytes, intermediate level at week 3, trough level at week 6, and age at diagnosis. Our predictive model of remission at week 30 was obtained with an area under the receiver operating characteristic curve of 0.9 ± 0.12, a sensitivity of 89%, and a specificity of 75%.

CONCLUSIONS

This study showed the clinical relevance of measuring new infliximab levels to predict remission in patients with IBD. These findings lay the foundation for a personalized medicine in which biotherapies could be monitored at an early stage, thereby improving patients' clinical management.

High Sugar-Sweetened Beverage Consumption is Associated with Increased Healthcare Utilization in Inflammatory Bowel Disease: A Multiyear, Prospective Analysis

BACKGROUND

Dietary factors like sugar-sweetened beverage (SSB) consumption are known to impact disease course in a variety of illnesses; however, long-term outcomes are not well documented for inflammatory bowel disease.

OBJECTIVE

Does high consumption of SSBs lead to high healthcare utilization (hospitalizations and emergency department visits), inflammation and disease severity in patients with Inflammatory Bowel Disease?

DESIGN

A prospective cohort study was conducted from 2015-2019. Patients enrolled in the discovery study cohort were followed for 3 years whereas patients in the validation cohort were followed for 2 years. They underwent nutritional assessment and received routine care. Dietary intakes of SSBs and fiber were quantified by a validated, self-reported questionnaire.

PARTICIPANTS/SETTING

For the discovery study cohort, 1133 adult patients were recruited from the University of Pittsburgh Medical Center (UPMC) Digestive Disease Clinic in Pittsburgh, PA. Eligible patients had a pre-existing diagnosis of Crohn's disease (CD) or Ulcerative colitis (UC) and had at least annual follow-up at this tertiary referral center.

EXPOSURE

High SSB consumption was defined as 7 or more SSBs per week. Moderate was defined as greater than 2 but fewer than 7 SSBs per week. Low SSB consumption was defined as 2 or fewer SSBs per week.

MAIN OUTCOME MEASURES

Primary outcome was time to hospitalization and emergency department visits. Secondary outcomes assessed laboratory markers of disease severity and inflammation. Tertiary outcomes assessed time to hospitalization and emergency department visits in a subsequent independent cohort of patients.

STATISTICAL ANALYSIS PERFORMED

Multivariable logistic regression, Kaplan-Meier, Cox proportional hazards modeling RESULTS: The discovery cohort included of 1133 adult IBD patients (female 58%, CD 70%, UC 30%, Median age 46y). Low SSB consumption, moderate SSB consumption, and high SSB consumption occurred in 57%, 17%, and 26% in the discovery cohort respectively. Among patients without active disease at enrollment, high SSB consumption was associated with decreased time to hospitalization and emergency department visits when compared to low SSB consumption (HR 1.55 [1.06 - 2.27]; HR 1.53 [1.10 - 2.13]). In terms of disease severity and inflammatory biomarkers, high SSB consumption was associated with increase odds of elevated erythrocyte sedimentation rate (OR 2.04 [1.31-3.18]), elevated C-reactive protein (OR 1.60 [1.07-2.37]), Eosinophilia (OR 1.88 [1.06-3.335]), and Monocytosis (OR 1.81 [1.18-2.79]) when compared to low SSB consumption after adjusting for baseline differences. Lastly, the validation cohort produced similar results to our primary outcome (high SSB consumption was associated with decreased time to hospitalization and emergency department visits when compared to low SSB consumption).

CONCLUSION

High SSB consumption was associated with decreased time to hospitalization and emergency department visits. Furthermore, high SSB consumption is associated with disease severity biomarkers and inflammation. Prospective studies assessing the therapeutic impact of nutritional counseling and decreased SSB consumption on long-term IBD clinical course are warranted.

Role of Eosinophils in Intestinal Inflammation and Fibrosis in Inflammatory Bowel Disease: An Overlooked Villain?

Eosinophils are leukocytes which reside in the gastrointestinal tract under homeostatic conditions, except for the esophagus which is normally devoid of eosinophils. Research on eosinophils has primarily focused on anti-helminth responses and type 2 immune disorders. In contrast, the search for a role of eosinophils in chronic intestinal inflammation and fibrosis has been limited. With a shift in research focus from adaptive to innate immunity and the fact that the eosinophilic granules are filled with inflammatory mediators, eosinophils are becoming a point of interest in inflammatory bowel diseases. In the current review we summarize eosinophil characteristics and recruitment as well as the current knowledge on presence, inflammatory and pro-fibrotic functions of eosinophils in inflammatory bowel disease and other chronic inflammatory conditions, and we identify research gaps which should be covered in the future.

Bacterial Translocation as Inflammatory Driver in Crohn's Disease

Crohn’s disease (CD) is a chronic inflammatory disorder of the gastrointestinal tract responsible for intestinal lesions. The multifactorial etiology attributed to CD includes a combination of environmental and host susceptibility factors, which result in an impaired host–microbe gut interaction. Bacterial overgrowth and dysbiosis, increased intestinal barrier permeability, and altered inflammatory responses in patients with CD have been described in the past. Those events explain the pathogenesis of luminal translocation of bacteria or its products into the blood, a frequent event in CD, which, in turn, favors a sustained inflammatory response in these patients. In this review, we navigate through the interaction between bacterial antigen translocation, permeability of the intestinal barrier, immunologic response of the host, and genetic predisposition as a combined effect on the inflammatory response observed in CD. Several lines of evidence support that translocation of bacterial products leads to uncontrolled inflammation in CD patients, and as a matter of fact, the presence of gut bacterial genomic fragments at a systemic level constitutes a marker for increased risk of relapse among CD patients. Also, the significant percentage of CD patients who lose response to biologic therapies may be influenced by the translocation of bacterial products, which are well-known drivers of proinflammatory cytokine production by host immune cells. Further mechanistic studies evaluating cellular and humoral immune responses, gut microbiota alterations, and genetic predisposition will help clinicians to better control and personalize the management of CD patients in the future.

Correlation Between the Transient Elevation of Peripheral Eosinophil Count During Radiotherapy and Acute Diarrhea

BACKGROUND/AIM

This study aimed to evaluate the association between the change in peripheral eosinophil count during postoperative pelvic radiotherapy and gastrointestinal (GI) toxicities in patients with cervical cancer.

PATIENTS AND METHODS

The medical records of 163 patients with cervical cancer who underwent postoperative concurrent chemoradiotherapy between 2000 and 2016 were analyzed.

RESULTS

Among the peripheral blood cell counts, transient elevation of the eosinophil count was observed during radiotherapy. Of the 163 patients, 117 developed grade ≥2 diarrhea during radiotherapy, and 25 patients developed grade ≥2 late GI toxicities. In multivariate analysis, the maximum eosinophil count and age emerged as independent predictors of grade ≥2 acute diarrhea during radiotherapy, while bowel bag V _{40 Gy} and age were predictive of grade ≥2 late GI toxicities.

CONCLUSION

Early detection of transient elevation of eosinophil may facilitate early treatment of acute diarrhea during radiotherapy.

The Role of Biomarkers in Surgery for Ulcerative Colitis: A Review

Ulcerative colitis (UC) is an inflammatory condition that generally affects the rectum and extends proximally into the colon in a continuous, distal-to-proximal pattern. Surgical resection (total proctocolectomy) is the only cure for UC and is often necessary in managing complicated or refractory disease. However, recent advances in biologically targeted therapies have resulted in improved disease control, and surgery is required in only a fraction of cases. This ever-increasing array of options for medical management has added complexity to surgical decision-making. In some circumstances, the added time required to ensure failure of medical therapy can delay colectomy in patients who will ultimately need it. Indeed, many patients with severe disease undergo trials of multiple medical therapies prior to considering surgery. In severe cases of UC, continued medical management has been associated with a delay to surgical intervention and higher rates of morbidity and mortality. Biomarkers represent a burgeoning field of research, particularly in inflammatory bowel disease and cancer. This review seeks to highlight the different possible settings for surgery in UC and the role various biomarkers might play in each.

Inflammatory bowel disease presenting with pyodermatitis-pyostomatitis vegetans in a pediatric patient: A case report and review of the literature

Pyodermatitis-pyostomatitis vegetans (PD-PSV) is rarely reported in the pediatric population. Here, we provide a review of pediatric PD-PSV in the literature and report a case of widespread PD-PSV in a 15-year-old male without a previous history of inflammatory bowel disease or gastrointestinal symptoms. Clinical, histological, and immunopathological workup established PD-PSV and revealed subclinical Crohn's disease. Treatment with infliximab was effective in inducing rapid resolution of the lesions.

Blood-based prognostic biomarkers in Crohn's Disease patients on biologics: a promising tool to predict endoscopic outcomes

OBJECTIVE

There is a growing need for biomarkers to predict therapeutic outcome in Crohn's disease (CD).

MAIN OUTCOME MEASURES

The aim was to evaluate whether NLR (neutrophil-to-lymphocyte ratio), PLR (platelet-to-lymphocyte ratio), ELR (eosinophil-to-lymphocyte ratio), and ENLR (eosinophil*neutrophil-to-lymphocyte ratio), could be prognostic biomarkers of endoscopic response (ER) when starting biologics.

RESEARCH DESIGN AND METHODS

Patients with CD who started biologics were enrolled. Multivariate analysis was used to evaluate whether NLR, PLR, ELR and ENLR at baseline and at w12 could predict ER (Simple Endoscopic Score for Crohn's disease [SES-CD] ≤2 or SES-CD≤2 and Rutgeerts i0-i1) after 52 weeks of treatment. Area under the curve (AUC) was calculated to find the cutoffs.

RESULTS

107 patients were included. Patients who achieved ER had significantly lower baseline NLR (p = 0.025), ELR (p = 0.013), and ENLR (p = 0.020) compared with those without ER; results after 12 weeks of treatment for ELR (p = 0.006) and ENLR (p = 0.003). AUC was 0.64 (p = 0.003), 0.67 (p = 0.006) and 0.65 (p = 0.014) for NLR, ELR and ENLR.

CONCLUSIONS

Low NLR, ELR and ENLR can predict ER and could be used in clinical practice for a better management of CD patients.

The Clinical Characteristics and Treatment Outcomes of Concomitant Eosinophilic Esophagitis and Inflammatory Bowel Disease

Background

The clinical characteristics and treatment outcomes in patients with eosinophilic esophagitis (EoE) and inflammatory bowel disease (IBD) have not been extensively investigated.

Methods

We determined treatment outcomes and frequencies of disease-related complications in patients with EoE and IBD.

Results

Among 69 patients who met inclusion criteria, 39 (56.5%) had a diagnosis of Crohn disease. Clinical and histologic response rates to proton pump inhibitors and topical steroids were 25.9% and 24.4%, respectively.

Conclusions

Lower than expected clinical and histologic response rates for EoE suggest the combination of EoE and IBD is a medically refractory phenotype with more difficult to treat EoE.

Selecting End Points for Disease-Modification Trials in Inflammatory Bowel Disease: the SPIRIT Consensus From the IOIBD

BACKGROUND AND AIMS

Inflammatory bowel diseases (IBD), encompassing Crohn's disease (CD) and ulcerative colitis (UC), are chronic and disabling disorders. Prospective disease-modification trials to prevent disease progression are eagerly awaited. However, disease progression is not clearly defined. The objective of the Selecting End PoInts foR Disease-ModIfication Trials (SPIRIT) initiative was to achieve international expert consensus on the endpoints to be used in future IBD-disease modification trials.

METHODS

This initiative under the auspices of the International Organization for the Study of Inflammatory Bowel Diseases (IOIBD) began with a systematic literature search to evaluate the current evidence on the definition of disease progression in IBD. On October 22, 2019, a consensus meeting took place during the United European Gastroenterology Week (UEGW) Congress in Barcelona, during which predefined proposed statements were discussed in a plenary session and voted on anonymously. Agreement was defined as at least 75% of participants voting for any one statement.

RESULTS

The group agreed that the ultimate therapeutic goal in both CD and UC is to prevent disease impact on patient's life (health-related quality of life, disability, fecal incontinence), midterm complications (encompass bowel damage in CD, IBD-related surgery and hospitalizations, disease extension in UC, extraintestinal manifestations, permanent stoma, short bowel syndrome), and long-term complications (gastrointestinal and extraintestinal dysplasia or cancer, mortality).

CONCLUSIONS

Recommendations on which goals to achieve in disease-modification trials for preventing disease progression in patients with IBD are proposed by the SPIRIT consensus. However, these recommendations will require validation in actual clinical studies before implementation in disease-modification trials.

Intestinal eosinophils: multifaceted roles in tissue homeostasis and disease

Intestinal eosinophils are largely considered to be one of the central immune effector cells during helminth infection and disorders such as eosinophilic oesophagitis and food allergies. Given the abundance of these cells present in the gastrointestinal tract at homeostasis, emerging studies now reveal novel roles for eosinophils in the development and regulation of immunity, and during tissue repair. In addition, the identification of distinct eosinophil subsets indicates that we must consider the heterogeneity of these cells and how they differentially participate in mucosal immunity at steady state and during disease. Here, we summarise the literature on intestinal eosinophils, and how they contribute to mucosal homeostasis through immune regulation and interactions with the microbiome. We then explore the divergent roles of eosinophils in the context of eosinophilic gastrointestinal disorders and during helminth infection, whereby we discuss key observations and differences that have emerged from animal models and human studies. Lastly, we consider the possible interactions of eosinophils with the enteric nervous system, and how this represents an exciting area for future research which may inform future therapeutic targets.

Phenotype and Natural History of Inflammatory Bowel Disease in Patients With Concomitant Eosinophilic Esophagitis

BACKGROUND

The co-occurrence of autoimmune diseases is well recognized. Though studies have suggested that eosinophilic esophagitis (EoE) is more common in patients with inflammatory bowel diseases (IBD), whether co-occurrence of EoE modifies natural history of IBD is unknown.

METHODS

This was a retrospective case-control study at a referral center. Cases consisted of patients with IBD and EoE, with both diseases diagnosed using established criteria. Controls comprised patients with IBD without concomitant EoE. Two controls were selected per case and were matched for duration of IBD. Relevant covariates regarding disease presentation and natural history were extracted from the medical record and compared between the 2 groups.

RESULTS

A total of 95 IBD-EoE cases and 190 IBD controls were included in our study. The IBD-EoE group was diagnosed with IBD at a younger age than those with IBD alone (22.3 years vs 29.0 years; P < 0.001) and were more likely to be male (80.0% vs 45.8%; P < 0.001). There were no differences in medical or surgical therapy for IBD between the 2 groups. Among those with IBD-EoE, patients for whom IBD was diagnosed first presented more commonly with dysphagia (50.8% vs 26.9%; P = 0.04) and endoscopically had evidence of esophageal rings (50.0% vs 23.1%; P = 0.02) when compared with those where EoE was diagnosed first.

CONCLUSION

Patients with concurrent IBD-EoE are diagnosed at a younger age and more likely to be males but have similar natural history as those without EoE. There were differences in EoE phenotype based on whether the EoE or IBD was diagnosed first.

Monocytosis Is a Biomarker of Severity in Inflammatory Bowel Disease: Analysis of a 6-Year Prospective Natural History Registry

BACKGROUND

Inflammatory bowel disease (IBD) is associated with alterations of the innate and adaptive immune systems. Monocytes respond to inflammation and infection, yet the relationship between monocytosis and IBD severity is not fully understood. We aimed to characterize the prevalence of monocytosis in IBD and the association between monocytosis and disease severity and IBD-related health care utilization.

METHODS

We used a multiyear, prospectively collected natural history registry to compare patients with IBD with monocytosis to those without monocytosis, among all patients and by disease type.

RESULTS

A total of 1290 patients with IBD (64.1% with Crohn disease; 35.9% with ulcerative colitis) were included (mean age 46.4 years; 52.6% female). Monocytosis was found in 399 (30.9%) of patients with IBD (29.3% with Crohn disease; 33.9% with ulcerative colitis). Monocytosis was significantly associated with abnormal C-reactive protein level and erythrocyte sedimentation rate, anemia, worse quality of life, active disease, and increased exposure to biologics (all P < 0.001). Compared with patients without monocytosis, patients with monocytosis had a 3-fold increase in annual financial health care charges (median: $127,013 vs. $32,925, P < 0.001) and an increased likelihood of hospitalization (adjusted odds ratio [AOR], 4.5; P < 0.001), IBD-related surgery (AOR, 1.9; P = 0.002), and emergency department (ED) use (AOR, 2.8; P < 0.001). Patients with monocytosis had a shorter time to surgery, hospitalization, and ED visit after stratifying by disease activity (all P < 0.05).

CONCLUSIONS

Patients with IBD with monocytosis, regardless of disease type, are at increased risk for worse clinical outcomes, hospitalization, surgery, and ED use. Peripheral monocytosis may represent a routinely available biomarker of a distinct subgroup with severe disease.

Early microscopic findings in preclinical inflammatory bowel disease

BACKGROUND

The immune response involved in the pathogenesis of Inflammatory Bowel Disease (IBD) may be present years before the diagnosis, but the characteristics of the disease during the preclinical period have been scarcely investigated.

AIM

To describe the microscopic findings of preclinical IBD and its relationship with the natural history of the disease.

METHODS

Medical records from all patients with an incidental diagnosis of IBD during a screening colonoscopy were included in this multicentric and retrospective study. We assessed 15 histologic items in the biopsy samples at diagnosis, and the Geboes score was calculated in patients with Ulcerative Colitis (UC). The main outcome was the development of gastrointestinal symptoms during follow-up.

RESULTS

We included 110 patients (79 UC, 24 Crohn's Disease (CD) and 7 with unclassified disease). In UC the most common histologic findings were acute or chronic inflammatory infiltrate and crypt epithelial polymorphs, while in CD we observed acute or chronic neutrophilic infiltrate and epithelial irregularity. Granuloma were only observed in 4% of CD patients. Crypt distortion and the infiltration of neutrophils in the epithelium were associated with a higher risk of developing symptomatic disease.

CONCLUSIONS

Preclinical IBD shows specific microscopic findings and they are associated with the progression to symptomatic disease.

Peripheral Blood Eosinophilia and Long-term Severity in Pediatric-Onset Inflammatory Bowel Disease

BACKGROUND

Peripheral blood eosinophilia (PBE) is a biomarker of an aggressive multiyear natural history in adults with inflammatory bowel diseases (IBDs). Additionally, PBE at diagnosis is associated with higher disease activity in pediatric-onset IBD. We sought to determine if PBE can function as a biomarker of long-term disease severity in pediatric-onset IBD patients who are followed into adulthood.

METHODS

We analyzed a consented, prospective, natural history IBD registry at an adult tertiary center from 2009 to 2018. Prevalence of PBE was evaluated in both pediatric- and adult-onset IBD patients. Demographics, clinical characteristics, and health care utilization data were compared in patients with and without PBE.

RESULTS

Among 2800 adult IBD patients, 23.4% had pediatric-onset disease. PBE was found in 34% of the pediatric-onset patients compared with 26.8% of the adult-onset IBD patients (P < 0.001). In the pediatric-onset IBD cohort, PBE was associated with higher rates of allergies (P < 0.0001), but not of asthma, allergic rhinitis, or primary sclerosing cholangitis. In the adult IBD patients with pediatric-onset disease, PBE was associated with higher rates of C-reactive protein elevation (P < 0.0001), erythrocyte sedimentation rate elevation (P < 0.0001), higher health care utilization, and higher average health care charges per year (P < 0.00001).

CONCLUSIONS

Peripheral blood eosinophilia was more prevalent in adult IBD patients with pediatric-onset compared with adult-onset disease. Among all IBD patients with long-term follow-up, PBE defined a subgroup with more severe illness. These data suggest that PBE may be a biomarker for a high-risk subgroup with high cost trajectory and long-term severity in pediatric-onset IBD that persists into adulthood.

Strongyloides stercoralis colitis in a patient positive for human T-cell leukaemia virus with rheumatoid arthritis during an anti-rheumatic therapy: a case report

An elderly woman with rheumatoid arthritis (RA) presented with a chief complaint of abdominal pain and diarrhoea while undergoing treatment with low-dose corticosteroids and abatacept. Endoscopic and histopathological findings revealed manifestations of ulcerative colitis (UC). An intermediate dose of corticosteroids and 5-aminosalicylic acid were administered. Abatacept was discontinued; the anti-TNF biologic, golimumab, was administered for treatment of both RA and UC. However, colitis worsened in response to this therapeutic regimen. Colonoscopy revealed severe mucosal lesions; larvae were detected in samples taken from multiple shallow mucosal ulcers. The patient was diagnosed with Strongyloides stercoralis colitis based on the results of an anti-parasite antibody test and examination of the larval DNA. Furthermore, serology revealed a positive test for antibodies against human T-cell leukaemia virus type 1 (HTLV-1). Immunosuppressive treatment was terminated; ivermectin was administered, which resulted in improvements in colitis symptoms within a few weeks. There are several published reports describing S. stercoralis colitis as a lethal mimic of UC. Corticosteroid and anti-TNF therapies have been reported as among the major risk factors associated with strongyloidiasis in patients with HTLV-1 infection. Therefore, HTLV-1 and Strongyloides infections may be considered in cases of new-onset gastrointestinal symptoms during immunosuppressive therapy, particularly in HTLV-1-endemic regions.

Clinical Characteristics of Inflammatory Bowel Disease Patients Requiring Long-Term Parenteral Support in the Present Era of Highly Effective Biologic Therapy

BACKGROUND

Despite advances in the medical management of inflammatory bowel disease (IBD), a subset of patients may require extensive surgery, leading to short-bowel syndrome/intestinal failure requiring long-term home parenteral nutrition (PN) or customized intravenous fluid (IVF) support. Our aim was to further define the characteristics of IBD patients requiring home PN/IVF.

METHODS

This is an observational study from a prospective IBD research registry. Patients receiving long-term home PN/IVF support during 2009-2015 were identified and compared with remaining IBD patients. Demographics, surgical history, smoking, narcotic use, IBD treatment, healthcare charges, and presence of biomarkers were reviewed. The IBD-PN group was stratified into 3 groups based on median healthcare charges.

RESULTS

Of 2359 IBD patients, there were 25 (1%, 24 with Crohn's disease) who required home PN/IVF, and 250 randomly selected IBD patients matched for disease type formed the control population. Median duration of PN use was 27 months (interquartile range, 11-66). PN use was significantly associated with smoking, narcotic use, IBD-related operations, and lower quality-of-life scores. Among IBD-PN patients, 7 of 25 (28%, 3 after use of teduglutide) were able to successfully discontinue this modality. Median healthcare charges in the IBD-PN group were $51,456 annually. Median charges in the controls were $3427. Period prevalence mortality was 11.5% in IBD-PN and 3.8% in controls.

CONCLUSIONS

IBD patients requiring long-term home PN/IVF support are a small minority in the present era of immunomodulator/biologic therapy. These refractory patients have a 15-fold increase in annual median healthcare charges compared with control IBD patients.

Mucosal Eosinophilia Is an Independent Predictor of Vedolizumab Efficacy in Inflammatory Bowel Diseases

BACKGROUND

Peripheral and mucosal eosinophilia may be associated with more aggressive disease in inflammatory bowel disease (IBD) patients. Vedolizumab blocks T lymphocytes, eosinophil adhesion, and extravasation in the gastrointestinal tract. It is not known if mucosal eosinophilia is a predictor for the therapeutic efficacy of vedolizumab.

METHODS

This was a retrospective cohort study of IBD patients with ileal or colonic biopsies who were off steroids before starting vedolizumab. Biopsies were rereviewed by pathologists, and mean eosinophil density was quantified. Patient characteristics and steroid-free clinical response 6 months after beginning vedolizumab were determined. Features were compared between nonresponders and responders, and multivariable logistic regression was performed to identify predictors of clinical response.

RESULTS

Of 251 IBD patients starting vedolizumab therapy, 65 patients (48% Crohn's disease, 52% ulcerative colitis) met inclusion criteria. All IBD patients not responding to vedolizumab were more likely to have a higher baseline mean eosinophil count (340 ± 156 vs 236 ± 124; P = 0.004), be previously exposed to an anti-TNF (96% vs 56%; P = 0.001), and be male (58% vs 28%; P = 0.02). Mean eosinophil counts were significantly increased in colonic biopsies in UC nonresponders (438 ± 149 vs 299 ± 145; P = 0.01). A similar trend was seen in CD nonresponders. On multivariable analysis, colonic eosinophil density and prior anti-TNF exposure-and the combination of both-were independent predictors of response.

CONCLUSION

In ulcerative colitis, colonic eosinophilia and prior anti-TNF exposure were independent predictors of 6-month clinical nonresponse to vedolizumab. Mucosal eosinophil density as a novel biomarker should be explored in larger patient cohorts.Aside from the previous anti-TNF exposure, eosinophil density in the colon of patients with UC is a negative predictor for a steroid-free long-term response to vedolizumab. The degree colonic eosinophilia may be a novel biomarker that should be further explored.

The Emerging Role of Eosinophils as Multifunctional Leukocytes in Health and Disease

Eosinophils are terminally differentiated cytotoxic effector cells that have a role in parasitic infections and allergy by releasing their granule-derived cytotoxic proteins. However, an increasing number of recent observations indicate that eosinophils are not only associated with the pathogenesis of a wide range of diseases, but also contribute to the maintenance of homeostatic responses in previously underappreciated diverse tissues, such as the gastrointestinal (GI) tract and adipose tissue. In this review, we describe biological characteristics of eosinophils, as their developmental properties, permissive proliferation and survival, degranulation activity, and migration properties enable them to distribute to both homeostatic and inflamed tissues. We describe pathologic aspects of eosinophils with a role in asthma and in various GI diseases, including eosinophilic GI disorders, inflammatory bowel disease, and radiation-induced enteropathy. Finally, we discuss the beneficial role of eosinophils, which contribute to the resolution of pathogenic conditions and to the modulation of homeostatic biologic responses.

Gastrointestinal Manifestations of Hypereosinophilic Syndromes and Mast Cell Disorders: a Comprehensive Review

Hypereosinophilic syndrome and mastocytosis are relatively rare proliferative diseases encountered in the general population. However, allergists frequently consider these disorders in the differential of patients presenting with gastrointestinal, pulmonary, cutaneous, and allergic symptoms. Gastrointestinal symptoms are some of the most frequent and/or debilitating aspects of both disease states and in many cases lead to poor quality of life and functional limitation for the patient. They are the third most common clinical manifestation in hypereosinophilic syndrome and have been found to be the most distressful aspect of the disorder in those with systemic mastocytosis. Both eosinophils and mast cells play integral parts in normal gut physiology, but when and how exactly their effector functionality translates into clinically significant disease remains unclear, and the available literature regarding their pathophysiology remains sparse. Eosinophils and mast cells even, in fact, may not necessarily function in isolation from each other but can participate in bidirectional crosstalk. Both are affected by similar mediators and can also influence one another in a paracrine fashion. Their interactions include both production of soluble mediators for specific eosinophil and mast cell receptors (for example, eosinophil recruitment and activation by mast cells releasing histamine and eotaxin) as well as direct physical contact. The mechanistic relationship between clonal forms of hypereosinophilia and systemic mastocytosis has also been explored. The nature of gastrointestinal symptomatology in the setting of both hypereosinophilic syndrome and mast cell disease is frequently manifold, heterogeneous, and the lack of better targeted therapy makes diagnosis and management challenging, especially when faced with a substantial differential. Currently, the management of these gastrointestinal symptoms relies on the treatment of the overall disease process. In hypereosinophilia patients, systemic corticosteroids are mainstay, although steroid-sparing agents such as hydroxyurea, IFN-α, methotrexate, cyclosporine, imatinib, and mepolizumab have been utilized with varying success. In mastocytosis patients, anti-mediator therapy with antihistamines and mast cell stabilization with cromolyn sodium can be considered treatments of choice, followed by other therapies yet to be thoroughly studied, including the role of the low-histamine diet, corticosteroids, and treatment of associated IBS symptoms. Given that both eosinophils and mast cells may have joint pathophysiologic roles, they have the potential to be a combined target for therapeutic intervention in disease states exhibiting eosinophil or mast cell involvement.

Identification of differentially expressed genes between the colon and ileum of patients with inflammatory bowel disease by gene co-expression analysis

OBJECTIVE

We aimed to identify differentially expressed genes (DEG) in patients with inflammatory bowel disease (IBD).

METHODS

RNA-seq data were obtained from the Array Express database. DEG were identified using the edgeR package. A co-expression network was constructed and key modules with the highest correlation with IBD inflammatory sites were identified for analysis. The Cytoscape MCODE plugin was used to identify key sub-modules of the protein-protein interaction (PPI) network. The genes in the sub-modules were considered hub genes, and functional enrichment analysis was performed. Furthermore, we constructed a drug-gene interaction network. Finally, we visualized the hub gene expression pattern between the colon and ileum of IBD using the ggpubr package and analyzed it using the Wilcoxon test.

RESULTS

DEG were identified between the colon and ileum of IBD patients. Based on the co-expression network, the green module had the highest correlation with IBD inflammatory sites. In total, 379 DEG in the green module were identified for the PPI network. Nineteen hub genes were differentially expressed between the colon and ileum. The drug-gene network identified these hub genes as potential drug targets.

CONCLUSION

Nineteen DEG were identified between the colon and ileum of IBD patients.

Ileal Gene Expression Data from Crohn's Disease Small Bowel Resections Indicate Distinct Clinical Subgroups

BACKGROUND AND AIMS

Heterogeneity in Crohn's disease [CD] provides a challenge for the development of effective therapies. Our goal was to define a unique molecular signature for severe, refractory CD to enable precision therapy approaches to disease treatment and to facilitate earlier intervention in complicated disease.

METHODS

We analysed clinical metadata, genetics, and transcriptomics from uninvolved ileal tissue from CD patients who underwent a single small bowel resection. We determined transcriptional risk scores, cellular signatures, and mechanistic pathways that define patient subsets in refractory CD.

RESULTS

Within refractory CD, we found three CD patient subgroups [CD1, CD2, and CD3]. Compared with CD1, CD3 was enriched for subjects with increased disease recurrence after first surgery [OR = 6.78, p = 0.04], enhanced occurrence of second surgery [OR = 5.07, p = 0.016], and presence of perianal CD [OR = 3.61, p = 0.036]. The proportion of patients with recurrence-free survival was smaller in CD3 than in CD1 (p = 0.02, median survival time [months] in CD1 = 10 and CD3 = 6). Overlaying differential gene expression between CD1 and CD3 on CD subgroup-associated genetic polymorphisms identified 174 genes representing both genetic and biological differences between the CD subgroups. Pathway analyses using this unique gene signature indicated eukaryotic initiation factor 2 [eIF2] and cyclic adenosine monophosphate [cAMP] signalling to be dominant pathways associated with CD3. Furthermore, the severe, refractory subset, CD3, was associated with a higher transcriptional risk score and enriched with eosinophil and natural killer T [NKT] cell gene signatures.

CONCLUSION

We characterized a subset of severe, refractory CD patients who may need more aggressive treatment after first resection and who are likely to benefit from targeted therapy based on their genotype and tissue gene expression signature.

Increased Prevalence of Esophageal Eosinophilia in Patients with Inflammatory Bowel Disease

Background

The overlap between eosinophilic esophagitis (EoE) and inflammatory bowel disease (IBD) has not been extensively examined. We aimed to assess the prevalence of esophageal eosinophilia in patients with IBD.

Methods

We conducted a retrospective cohort study using diagnostic codes to identify adults with EoE and IBD between 2008 and 2016 at a tertiary care center. Electronic medical records were reviewed to extract clinical, endoscopic, and treatment data. Patients with esophageal eosinophilia and IBD were compared to EoE cases without IBD.

Results

Of 621 EoE patients and 4,814 IBD patients identified, 35 had a code for both diseases and 12 were confirmed to have overlapping IBD and esophageal eosinophilia. The prevalence of esophageal eosinophilia in IBD was 12/4814 (0.25%), and the prevalence of confirmed EoE in IBD was 5/4,814 (0.10%). There were no substantial clinical, endoscopic, or histologic differences between EoE patients with and without IBD. IBD was diagnosed before esophageal eosinophilia 92% of the time, with an average time between diagnoses of 9.6 years. Of the IBD patients, 71% were started on biologic anti-tumor necrosis factor-α therapy an average of 7.6 years prior to developing esophageal eosinophilia.

Conclusions

The prevalence of esophageal eosinophilia in IBD is 5 times higher than expected in the general population (0.25 vs. 0.05%) and EoE in IBD is 2 times higher than expected (0.10 vs. 0.05%). Upper gastrointestinal (GI) symptoms in patients with IBD should merit evaluation not only for upper GI Crohn's disease, but also for esophageal eosinophilia.