Assessing Early Life Factors for Eosinophilic Esophagitis: Lessons From Other Allergic Diseases

Early life exposures as risk factors for non-esophageal eosinophilic gastrointestinal diseases

OBJECTIVES

Early life exposures increase risk of eosinophilic esophagitis (EoE), but it is unknown whether they contribute to increased risk for non-EoE eosinophilic gastrointestinal diseases (EGIDs). We aimed to assess the association between prenatal, antenatal, and early life factors and non-EoE EGIDs.

METHODS

We conducted a case-control study based in EGID Partners, an online patient-centered research network. Adults (≥18 years) with non-EoE EGIDs, caregivers of children <18 years of age with an EGID, and non-EGID adult controls were eligible. Subjects completed our Early Life Exposure Questionnaire, detailing maternal and early childhood exposures. We assessed for associations between non-EoE EGIDs and early life exposures, focusing on exposures previously evaluated in association with EoE.

RESULTS

We analyzed 61 non-EoE EGID cases and 20 controls. Of the EGID cases, 14 had eosinophilic gastritis, 19 had eosinophilic enteritis, 6 had eosinophilic colitis, and 22 had multiple areas affected; additionally, 30 had esophageal involvement. Relative to controls, EGID cases were more likely to have had antenatal/perinatal pregnancy-related complications (43% vs 13%; p = 0.02), NICU admission (20% vs 0%; p = 0.03), and antibiotics in infancy (43% vs 10%; p = 0.01). With adjustment for age at diagnosis, we observed increased odds of an EGID for pregnancy complications (aOR 3.83; 95% CI: 0.99-14.9) and antibiotic use in infancy (aOR 7.65; 95% CI: 1.28-45.7).

CONCLUSIONS

Early life factors, including pregnancy complications, NICU admission, and antibiotics in infancy, were associated with development of non-EoE EGIDs. The impact of early life exposures on non-EoE EGID pathogenic mechanisms should be investigated.

Pediatric eosinophilic esophagitis: a review for the clinician

Eosinophilic esophagitis (EoE) is a chronic clinical-pathologic disease characterized by eosinophilic infiltration of the esophageal epithelium with esophageal dysfunction symptoms.EoE can occur at any age and has different clinical manifestations depending on the age onset.To date, esophago-gastroduodenal endoscopy (EGD) with biopsy is the gold-standard for EoE diagnosis.According to the recent consensus guidelines, proton pump inhibitors, corticosteroids and elimination diets could be a first-line therapy option. The aim of the treatment is clinical and histological remission for preventing long-lasting untreatable fibrosis.A multidisciplinary approach (allergist, gastroenterology, dietitian, and pathologist) is recommended for managing patients affected by EoE, given the complexity of its treatment.This review will provide a practical guide to assist pediatricians treating children with EoE.Moreover, it highlights the unmet needs in diagnosis and treatment that require urgent attention from the scientific community in the aim of improving the management of patients with EoE.

Eosinophilic Esophagitis

Eosinophilic esophagitis is a recently defined condition that has dramatically increased in prevalence in the last several decades. It may occur at any age, but the clinical presentation in young children is often more vague than the classic solid food dysphagia and food impacting that are the major presenting symptoms of eosinophilic esophagitis in adults and adolescents. Successful therapies exist, including medications and dietary modifications, but disease typically recurs when the intervention is discontinued.

Early Life Risk Factors in Pediatric EoE: Could We Prevent This Modern Disease?

Eosinophilic esophagitis (EoE) is a chronic antigen-mediated inflammatory disease that affects the esophagus. In the last 20 years, a large number of epidemiological studies showed a significant increase in the incidence and prevalence of EoE, especially in developed countries. This phenomenon might correlate to the overall increase in pediatric allergic diseases or might be a result of improved medical awareness and knowledge through modern diagnostic instruments. Since 1993, when EoE was first recognized as a distinct clinical entity, several signs of progress in the pathophysiology of EoE were achieved. However, a few studies reported data on early risk factors for pediatric EoE and how these factors may interfere with genes. Currently, the most defined risk factors for EoE are male sex, Caucasian race, and atopic comorbidities. Other putative risk factors may include alterations in epithelial barrier function and fibrous remodeling, esophageal dysbiosis, variation in the nature and timing of oral antigen exposure, and early prescription of proton pump inhibitors and antibiotics. Notably, the timing and nature of food antigen exposure may be fundamental in inducing or reversing immune tolerance, but no studies are reported. This review summarized the current evidence on the risk factors that might contribute to the increasing development of EoE, focusing on the possible preventive role of early interventions.

Eosinophilic Esophagitis

Eosinophilic esophagitis is a recently defined condition that has dramatically increased in prevalence in the last several decades. It may occur at any age, but the clinical presentation in young children is often more vague than the classic solid food dysphagia and food impacting that are the major presenting symptoms of eosinophilic esophagitis in adults and adolescents. Successful therapies exist, including medications and dietary modifications, but disease typically recurs when the intervention is discontinued.

Epithelial origin of eosinophilic esophagitis

Eosinophilic esophagitis (EoE) is a chronic, allergen-driven inflammatory disease of the esophagus characterized predominantly by eosinophilic inflammation, leading to esophageal dysfunction. Converging data have placed the esophageal epithelium at the center of disease pathogenesis. In particular, the main EoE disease susceptibility loci at 2p23 and 5p22 encode for gene products that are produced by the esophageal epithelium: the intracellular protease calpain 14 and thymic stromal lymphopoietin, respectively. Furthermore, genetic and functional data establish a primary role for impaired epithelial barrier function in disease susceptibility and pathoetiology. Additionally, the EoE transcriptome, a set of genes dysregulated in the esophagi of patients with EoE, is enriched in genes that encode for proteins involved in esophageal epithelial cell differentiation. This transcriptome has a high proportion of esophagus-specific epithelial genes that are notable for the unexpected enrichment in genes encoding for proteases and protease inhibitors, as well as in IL-1 family genes, demonstrating a previously unappreciated role for innate immunity responses in the esophagus under homeostatic conditions. Among these pathways, basal production of the serine protease inhibitor, Kazal-type 7 (SPINK7) has been demonstrated to be part of the normal differentiation program of esophageal epithelium. Profound lost expression of SPINK7 occurs in patients with EoE and is sufficient for unleashing increased proteolytic activity (including urokinase plasminogen activator), impaired barrier function, and production of large quantities of proinflammatory and proallergic cytokines, including thymic stromal lymphopoietin. Collectively, we put forth a model in which the esophagus is normally equipped as an anti-inflammatory sensing organ and that defects in this pathway, mediated by epithelial protease/protease inhibitor imbalances, unleash inflammatory responses resulting in disorders, such as EoE.

Prenatal, intrapartum, and postnatal factors are associated with pediatric eosinophilic esophagitis

BACKGROUND

Multiple lines of evidence point to the potential importance of early-life environmental factors in the rapid increase in the incidence of eosinophilic esophagitis (EoE), but potential exposures have not been extensively studied.

OBJECTIVE

We sought to assess the association between prenatal, intrapartum, and postnatal factors and the development of pediatric EoE using a case-control study.

METHODS

Patients with EoE were recruited from an existing registry at Cincinnati Children's Hospital Medical Center (CCHMC). Population-based community control subjects were identified from a separate CCHMC registry. Mothers of study subjects were contacted and completed a Web-based questionnaire. Crude and adjusted models were used to estimate associations.

RESULTS

Mothers of 127 cases and 121 control subjects were included. We observed a positive association between several early-life factors and EoE, including prenatal (maternal fever: adjusted odds ratio [aOR], 3.18; 95% CI, 1.27-7.98; preterm labor: aOR, 2.18; 95% CI, 1.06-4.48), intrapartum (cesarean delivery: aOR, 1.77; 95% CI, 1.01, 3.09), and infancy (antibiotic use: aOR, 2.30; 95% CI, 1.21-4.38; use of an acid suppressant: aOR, 6.05; 95% CI, 2.55-14.40) factors. We observed an inverse association between having a furry pet in infancy and EoE (aOR, 0.58; 95% CI, 0.34-0.97). No associations were observed for breast-feeding or maternal multivitamin or folic acid supplement use.

CONCLUSION

Early-life factors, including maternal fever, preterm labor, cesarean delivery, and antibiotic or acid suppressant use in infancy, were associated with risk of pediatric EoE; having a pet in the home was protective. These results add to growing evidence that implicate early-life exposures in EoE pathogenesis.

Pathophysiology of Eosinophilic Esophagitis

Eosinophilic esophagitis is an emerging disease that is distinguished from gastroesophageal reflux disease by the expression of a unique esophageal transcriptome and the interplay of early life environmental factors with distinct genetic susceptibility elements at 5q22 (TSLP) and 2p23 (CAPN14). Rare genetic syndromes have uncovered the contribution of barrier disruption, mediated in part by defective desmosomes and dysregulated transforming growth factor beta production and signaling, to eosinophilic esophagitis pathophysiology. Experimental modeling has defined a cooperative role of activated eosinophils, mast cells, and the cytokines IL-5 and IL-13, mediated by allergic sensitization to multiple foods. Understanding these processes is opening the way to better treatment based on disrupting allergic inflammatory and type 2 cytokine-mediated responses, including anti-cytokine therapeutics and dietary therapy.

Epidemiology and Natural History of Eosinophilic Esophagitis

Eosinophilic esophagitis (EoE) has emerged over the past 2 decades as a major cause of upper gastrointestinal morbidity. Over this time, the epidemiology of EoE has also rapidly evolved. EoE has transformed from a rare case-reportable condition to disease that is commonly encountered in the gastroenterology clinic, hospital emergency room, and endoscopy suite. The incidence and prevalence are increasing at rates that outpace increased disease recognition. Current incidence estimates range from 5 to 10 cases per 100,000, and current prevalence estimates range from 0.5 to 1 case per 1000. We review the data and potential reasons behind this increase, examine risk factors, and identify important areas for research into disease etiology. The article also discusses the progression of EoE from an inflammatory to fibrostenotic phenotype. An accurate view of the natural history of EoE is central to discussions with patients regarding disease prognosis and decisions about long-term use of medical, endoscopic, and diet therapies. Progressive remodelling appears to be gradual, but not universal, and the duration of untreated disease is the best predictor of stricture risk. Ultimately, prospective, long-term outcome studies focusing on multiple aspects of disease activity are needed to fully understand the natural history of EoE.

Eosinophilic Esophagitis: Pathophysiology and Definition

Eosinophilic esophagitis is an adaptive immune response to patient-specific antigens, mostly foods. Eosinophilic esophagitis is not solely IgE-mediated and is likely characterized by Th2 lymphocytes with an impaired esophageal barrier function. The key cytokines and chemokines are thymic stromal lymphopoeitin, interleukin-13, CCL26/eotaxin-3, and transforming growth factor-β, all involved in eosinophil recruitment and remodeling. Chronic food dysphagia and food impactions, the feared late complications, are related in part to dense subepithelial fibrosis, likely induced by interleukin-13 and transforming growth factor-β.