The ability of biomarkers to assess the severity of atopic dermatitis

Background

To develop precision medicine for atopic dermatitis (AD), it is critical to establish relevant biomarkers. However, the characteristics of various biomarkers have not been fully understood. We previously carried out the Biomarkers to Predict Clinical Improvement of AD in Patients Treated with Dupilumab (B-PAD) study, a comprehensive nationwide study in Japan, to explore biomarkers for AD.

Objective

The aim of this study is to find biomarkers associated with objective and subjective clinical findings in patients with moderate-to-severe AD based on the B-PAD study and to identify biomarkers sensitive enough to assess the severity of AD.

Methods

We performed the B-PAD study as a consortium composed of 19 medical facilities in Japan, enrolling 110 patients with moderate-to-severe AD. We evaluated the Eczema Area and Severity Index (EASI) for objective assessment as well as the Patient-Oriented Eczema Measure (POEM) and a numeric rating scale for pruritus (pruritis-NRS) for subjective assessment, measuring 19 biomarkers at baseline.

Results

We found that 12, 6, and 7 biomarkers showed significant and positive associations with the EASI, POEM, and pruritis-NRS, respectively. Most of the biomarkers associated with either the POEM or the pruritis-NRS were included among the biomarkers associated with EASI. Of the biomarkers examined, CCL26/eotaxin-3 and SCCA2 were the most capable of assessing severity for EASI, as shown by the 2 kinds of receiver operating characteristic analyses, respectively, whereas lactate dehydrogenase was the best for both the POEM and pruritis-NRS, again using the 2 analyses.

Conclusion

We found biomarkers associated with the EASI, POEM, and pruritis-NRS, respectively, based on the B-PAD study. Moreover, we identified CCL26/eotaxin-3 and/or SCCA2 as the biomarkers having the greatest ability to assess severity in the EASI; lactate dehydrogenase did the same for the POEM and pruritis-NRS. These findings will be useful in treating patients with moderate-to-severe AD.

Changes in eotaxin-3 and pulmonary and activation-regulated chemokine levels in patients after dupilumab treatment: a systematic review and meta-analysis

Introduction

Dupilumab is approved for a variety of type 2 inflammatory diseases. Changes in chemokine levels during treatment require further analysis.

Aim

We evaluated changes in eotaxin-3 and PARC levels after dupilumab treatment through a meta-analysis, aiming to provide more comprehensive results.

Material and methods

Databases were searched to select eligible publications. The study quality was assessed after inclusion. The standardized mean difference (SMD) was used for evaluation.

Results

Four studies were included. Eotaxin-3 levels were not seen significantly decreased at weeks 1 and 12, with SMD = -0.39 (95% CI: -1.78, 0.99) and -2.60 (95% CI: -5.77, 0.57), respectively (p > 0.05). Eotaxin-3 levels decreased significantly at weeks 2, 4, 8, 16, 24, 36, and 52, with SMD = -0.94 (95% CI: -1.61, -0.27); -1.17 (95% CI: -1.49, -0.84); -1.20 (95% CI: -1.52, -0.88); -1.31 (95% CI: -1.83, -0.79); -4.57 (95% CI: -6.90, -2.33); -5.28 (95% CI: -5.52, -5.04); and -4.03 (95% CI: -4.22, -3.85) (p < 0.05), respectively. PARC levels decreased significantly at weeks 4, 8, 12, and 16, with SMD = -1.08 (95% CI: -1.59, -0.58); -1.17 (95% CI: -1.68, -0.66); -1.11 (95% CI: -1.61, -0.60); and -1.15 (95% CI: -1.66, -0.64) (p < 0.05), respectively.

Conclusions

Eotaxin-3 and PARC levels can be significantly reduced in patients treated with dupilumab.

The Role of Heparan Sulfate in CCL26-Induced Eosinophil Chemotaxis

Proinflammatory chemokine ligand 26 (CCL26, eotaxin-3) mediates transendothelial cell migration of eosinophils by binding and activating the G-protein-coupled (GPC) chemokine receptor 3 on the surface of eosinophilic cells. Here we have investigated the role of glycosaminoglycans (GAGs) as potential co-receptors in the process of CCL26-induced eosinophil chemotaxis. For this purpose, we have first identified the GAG-binding site of CCL26 by a site-directed mutagenesis approach in the form of an alanine screening. A panel of GAG-binding-deficient mutants has been designed, generated, and analyzed with respect to their binding affinities to heparan sulphate (HS) by isothermal fluorescence titration studies. This showed that basic amino acids in the α-helical part of CCL26 are strongly involved in GAG-binding. In chemotaxis experiments, we found that decreased GAG-binding affinity correlated with decreased chemotactic activity, which indicates an involvement of GAGs in eosinophil migration. This was further proven by the negative impact of heparinase III treatment and, independently, by the incubation of eosinophils with an anti heparan sulfate antibody. We finally investigated eosinophils’ proteoglycan (PG) expression patterns by real-time PCR, which revealed the highest expression level for serglycin. Including an anti-serglycin antibody in CCL26-induced eosinophil migration experiments reduced the chemotaxis of these immune cells, thereby proving the dependence of eosinophil mobilization on the proteoglycan serglycin.

Elevated Serum Leptin Levels in Patients With Eosinophilic Chronic Rhinosinusitis

Background: Eosinophilic chronic sinusitis (ECRS) is a subtype of CRS with nasal polyps (CRSwNP) that is frequently comorbid with asthma. Notably, ECRS patients often show a high recurrence of NPs after surgical resection. Leptin is a hormone produced by adipocytes that has been implicated in airway inflammatory diseases. However, to date, the role of leptin in ECRS has not been investigated. Objective: To determine whether the serum levels of leptin are altered in patients with ECRS. Methods: In total, 40 patients with ECRS, 15 patients with non-eosinophilic CRS (non-ECRS), and 12 individuals without CRS (control) were included in this study. Patient's serum leptin levels were assessed, and the number of eosinophils in their NPs were measured through a histological evaluation of the three densest areas with cellular infiltrate beneath the epithelial surface. Finally, nasal fibroblast cultures established from NPs were stimulated with varying concentrations of recombinant leptin in vitro to determine whether leptin affects eotaxin-3 (Chemokine (C-C motif) ligand 26 :26: CCL26) expression. Results: The serum leptin levels in both the ECRS and non-ECRS groups were significantly higher than those in the control subjects (p < 0.0001 vs. ECRS; p < 0.05 vs. non-ECRS). Furthermore, ECRS patients displayed significantly elevated serum leptin levels compared to non-ECRS patients (p < 0.001), although there was no difference in body mass index between the groups. Notably, serum leptin levels were correlated with the proportion of eosinophils in peripheral blood (r = 0.3575, p < 0.01) and the number of eosinophils in NPs (r = 0.5109, p < 0.0001). Serum leptin levels were also correlated with eotaxin-3 mRNA expression in NPs (r = 0.5374, p < 0.01). Finally, leptin significantly augmented eotaxin-3 expression in nasal fibroblasts established in vitro from NPs in a leptin receptor-dependent manner (p < 0.05). Conclusion: Leptin levels are elevated in ECRS patients and may both promote and indicate the severity of ECRS as well as systemic type 2-biased inflammatory responses. Combined, these data indicate that circulating leptin may play a significant role in the development of eosinophilic inflammation in NPs.

Interleukin-17A potentiates interleukin-13-induced eotaxin-3 production by human nasal epithelial cells from patients with allergic rhinitis

BACKGROUND

Interleukin (IL)-17A is involved in the pathogenesis of allergic rhinitis (AR). Increased expression of IL-17A is correlated with disease severity and nasal eosinophilia. However, the molecular mechanisms by which IL-17A contributes to T-helper 2 cytokine IL-13-driven pathology in AR remain unclear. We sought to obtain mechanistic insight into how IL-17A and IL-13 regulate the epithelial production of eotaxin-3 representing eosinophilic inflammation in AR.

METHODS

Human nasal epithelial cells (HNECs) from AR patients were cultured and stimulated with IL-17A, IL-13, or IL-17A and IL-13. Phosphorylated signal transducer activator of transcription 6 (p-STAT6) and suppressor of cytokine signaling 1 (SOCS1) in HNECs were assayed using Western blotting. Immunocytochemistry was used to determine p-STAT6-positive expression in the cells. Eotaxin-3 expression in the cells and culture supernatants was evaluated using real-time polymerase chain reaction and enzyme-linked immunosorbent assays.

RESULTS

Stimulation with IL-13 alone induced STAT6 phosphorylation and promoted p-STAT6 nuclear translocation, leading to eotaxin-3 production by HNECs. These effects were further enhanced by cotreatment with IL-13 and IL-17A, whereas IL-17A alone had no impact on STAT6 or eotaxin-3 expression. Incubation with IL-17A or IL-13 increased the level of SOCS1 protein in the cells, whereas the addition of IL-17A attenuated IL-13-induced SOCS1 expression.

CONCLUSION

IL-17A potentiated IL-13-driven STAT6 activation through the downregulation of SOCS1 expression, leading to enhancement of eotaxin-3 production by HNECs. These factors contributed to eosinophilic inflammation in AR.

Eotaxin-3 as a Plasma Biomarker for Mucosal Eosinophil Infiltration in Chronic Rhinosinusitis

Objective: Chronic rhinosinusitis with nasal polyps exhibits marked eosinophilic infiltration and its mucosal eosinophilia is associated with more severe symptoms. The Japanese epidemiological survey of refractory eosinophilic chronic rhinosinusitis found that patients with nasal polyps required multiple surgeries when there were higher infiltrating eosinophils in the mucosa. In order to identify plasma biomarkers for local eosinophil infiltration in rhinosinusitis for surgery, we examined the levels of molecules in the plasma of patients and compared the number of infiltrating eosinophils in the nasal mucosa.

Materials and Methods: Mucosal tissues from 97 patients with chronic rhinosinusitis (CRS) were obtained from the nasal polyps during surgery. Tissues were immediately fixed and sections were stained with hematoxylin-eosin. The number of eosinophils in the mucosa was counted at HPF (x 400). Blood samples were obtained and the plasma was stored at −80°C. We measured the plasma cytokine and chemokine levels using multiple assay systems according to the manufacturers' protocols. The tissues were divided into high- and low-eosinophil mucosal infiltration group for recurrence after endoscopic sinus surgery (ESS). We also observed chemokine secretion from nasal fibroblasts.

Results: The plasma level of eotaxin-3/ CC chemokine ligand 26 (CCL26) was significantly higher in the high-eosinophil mucosal infiltration group (p < 0.005). The number of infiltrating eosinophils in the mucosa was significantly higher in the group with the higher eotaxin-3 level (p < 0.001), but there was no significant difference in the blood eosinophil numbers among two groups. A significant positive correlation was found between the mucosal eosinophil count and the plasma levels of eotaxin-3 (p < 0.005). The levels of interleukin 33 (IL-33) (p < 0.001) and thymic stromal-derived lymphopoietin (TSLP) (p < 0.005) were significantly higher in the high-level eotaxin-3 group. IL-13 strongly induced the secretion of eotaxin-3 from human nasal fibroblasts (p < 0.05).

Conclusion: This is the first report suggesting eotaxin-3 as a plasma biomarker for mucosal eosinophil infiltration. Furthermore, the level of eotaxin-3 was found to be closely related to IL-33 and TSLP levels which indicate respiratory diseases.

Molecular basis and cellular mechanisms of eosinophilic esophagitis for the clinical practice

Eosinophilic esophagitis (EoE) is a chronic, allergen-driven inflammatory esophageal disease characterized by predominantly eosinophilic inflammation leading to esophageal dysfunction. Recent efforts to understand EoE have increased our knowledge of the disease. Areas covered: Multiple cells, molecules, and genes interplay with early life environmental factors in the pathophysiology of EoE to converge in the esophageal epithelium at the center of disease pathogenesis. Epithelial cells constitute a mayor cytokine source for TSLP and Calpain-14; an impaired epithelial barrier function allowing penetration of food and microbiota-derived antigens is involved in triggering and maintaining inflammation. Eosinophil and mast cell-derived products, including TGFβ, together with IL-1β and TNFα, promote epithelial mesenchymal transition in EoE, contributing to tissue remodeling by synthetizing and depositing extracellular matrix in subepithelial layers. This article aims to provide a state-of-the-art update on the pathophysiology of EoE applied to clinical practice, and latest research and developments with potential interest to improve the diagnosis and treatment of patients with EoE are revised. Expert commentary: Preliminary approaches have provided promising results toward incorporating minimally invasive methods for patient diagnosis and monitoring in clinical practice. Early diagnosis and optimized therapies will allow for personalized medicine in EoE.

Expressions of Eotaxin-3, Interleukin-5, and Eosinophil-Derived Neurotoxin in Chronic Subdural Hematoma Fluids

Eosinophils induce inflammation by releasing cytokines and cytotoxic granule proteins. Infiltration of eosinophilic granulocytes occurs in the outer membrane of chronic subdural hematomas (CSDHs). Eosinophils play an important role in the growth of CSDHs. However, the manner in which eosinophils accumulate within CSDH fluid remains undetermined. In the current study, we assessed the expression of eosinophil chemoattractants in CSDH fluids according to growth stage of CSDHs and examined the correlation between the two. CSDH fluids were obtained from 38 patients during trepanation surgery. Ecalectin, eotaxin-3, interleukin-5 (IL-5), and eosinophil-derived neurotoxin (EDN) concentrations were measured using enzyme-linked immunosorbent assay kits. For use as controls, serum samples were collected from 5 healthy adults, and cerebrospinal fluid (CSF) samples were collected from 5 adults with unruptured aneurysms. The percentage of eosinophils (%eosinophil) in CSDH fluids was calculated using Giemsa staining. Concentrations of ecalectin, eotaxin-3, IL-5, and EDN were nearly equivalent in serum and CSF samples; however, their concentrations were high in CSDH fluids. In particular, ecalectin and EDN levels in CSDH fluids were significantly higher than those in serum and CSF. Levels of eotaxin-3, IL-5, EDN, and %eosinophil were significantly higher in laminar type of CSDH, whereas that of ecalectin was not. The correlations between eotaxin-3 and IL-5, IL-5 and EDN, and EDN and %eosinophil were statistically significant (p < 0.01). Our data suggest that eotaxin-3 is a chemoattractant of eosinophils. IL-5 induces the activation of eosinophils subsequent to degranulation of EDN into CSDH fluids. These factors may serve as novel therapeutic targets for managing CSDH.

Immunohistochemical differentiation of eosinophilic esophageal myositis from eosinophilic esophagitis

BACKGROUND AND AIM

Eosinophilic esophagitis (EoE) is a Th2-mediated allergic disease of the esophageal epithelium, associated with antigen. We previously reported a case series for eosinophilic esophageal myositis (EoEM)-a novel eosinophilic gastrointestinal disorder defined as eosinophilic infiltration localized in the esophageal muscle layer-and diagnosed it by peroral endoscopic muscle biopsy. Here, we investigated the immunopathology of EoEM to differentiate it from EoE.

METHODS

Histological analysis was performed for three cases of EoEM and EoE, respectively. The results were compared with those of two control samples (non-eosinophilic gastrointestinal disorder full-layer esophagus). Using immunofluorescence, we analyzed the expression of the chemokine receptor CCR3 and its ligands eotaxin-1 and eotaxin-3 to investigate the eosinophilic reaction. Additionally, we determined the expression patterns of desmoglein-1 in the esophageal epithelium, which shows dysregulated expression in EoE.

RESULTS

Eosinophil infiltration was observed in the muscle layer (maximum number, 30, 36, 73/high-power field) and the epithelium (50, 44, 40/high-power field) for EoEM and EoE, respectively. In EoE esophageal epithelium, the number of eotaxin-3-positive epithelial cells was significantly increased together with CCR3-positive infiltrating cells. However, in EoEM, a number of eotaxin-1-positive and eotaxin-3-positive myocytes and vascular endothelial cells were increased in the esophageal muscle layer. A significant loss of desmoglein-1 expression was only observed in EoE, not in EoEM.

CONCLUSIONS

Eotaxin-1 and eotaxin-3 expression on the smooth muscle and vessels plays a role in the pathogenesis of EoEM, while EoE shows an epithelial eotaxin-3-dominant immunoreaction. Thus, the EoEM immunological pattern displays clear differences from that of EoE.

Drug evaluation review: dupilumab in atopic dermatitis

Atopic dermatitis (AD) is characterized by type 2 helper T (Th2) cell-driven inflammation. Dupilumab is a fully human monoclonal antibody directed against the IL-4 receptor α subunit that blocks the signaling of IL-4 and IL-13, both key cytokines in Th2-mediated pathways. In Phase I and II studies of adults with moderate-to-severe AD, dupilumab administered as monotherapy or with topical corticosteroids resulted in rapid, significant improvements in clinical efficacy, patient-reported outcomes, and Th2-related serum and tissue biomarkers, and shifted the RNA expression profile of lesional skin to a more nonlesional signature. In all clinical studies to date, dupilumab has shown a favorable safety profile with no dose-limiting toxicity. The robust effects of dupilumab on skin inflammation and pruritus confirm the pathogenic role of IL-4 and IL-13 signaling in adult AD, and further support the application of Th2 cytokine antagonists in the treatment of this disease.

Wogonin, a plant flavone from Scutellariae radix, attenuated ovalbumin-induced airway inflammation in mouse model of asthma via the suppression of IL-4/STAT6 signaling

Bronchial asthma is a chronic inflammatory disease of the airways characterized by a marked infiltration of eosinophils at the site of inflammation. Eotaxins are potent chemoattractants for eosinophils and play important roles in pathogenesis of asthma. In the course of screening for eotaxin-3 inhibitors, we found that wogonin showed potent inhibitory activity of interleukin-4 (IL-4)-induced eotaxin-3 expression in BEAS-2B cells. In this study, we examined the effects of wogonin on IL-4/STAT6 signaling pathway and biological implication in a mouse model of asthma. Wogonin inhibited IL-4-induced activation and nuclear translocation of STAT6 which plays a key role in either the transcription of STAT6-response genes or Th2 cytokine-mediated inflammation. Oral administration of wogonin significantly reduced activation of STAT6 in the lung and the expression of eotaxin and RANTES in bronchoalveolar lavage fluids. Histological examination of lung tissue demonstrated that wogonin significantly inhibited allergen-induced eosinophilic inflammation. Administration of wogonin reduced the total IgE and ovalbumin-specific IgE levels compared with the ovalbumin-challenged group. All of these data demonstrated that wogonin could alleviate airway inflammation through inhibition of STAT6 activation induced by Th2 cytokines. Our finding implicates a potential therapeutic value of wogonin in the treatment of asthma through regulation of IL-4/STAT6 signaling pathway.

Cellular and molecular immunological mechanisms in eosinophilic esophagitis: an updated overview of their clinical implications

Eosinophilic esophagitis (EoE) is a pathophysiologically complex disorder driven by distinct, multiple mechanisms involving a large number of cells, molecules, and genes. Associated with food allergy from its initial descriptions, a key role for the Th2-type cytokines IL-5 and IL-13 in recruiting and activating eosinophils has been described. Epithelial cells have been recognized as major effectors in initiating EoE, both through their recruitment of iNKT cells towards the esophageal epithelium, which constitutes a major cytokine source, and through the release of eotaxin-3 and other chemoattractants. Epithelial and mesenchymal-released TSLP is a key regulator for which a connecting role between the adaptive and innate mucosal-associated immune response has been suggested. Finally, activated eosinophil- and mast cell-derived TGF β1 secretion is crucial in EoE-associated tissue remodeling.

Nasal fluid release of eotaxin-3 and eotaxin-2 in persistent sinonasal eosinophilic inflammation

BACKGROUND

The aim of the present study was to measure eotaxin-3 (CCL26) and eotaxin-2 (CCL24) in nasal lavage fluid of patients with different forms of chronic sinonasal eosinophilic inflammation to evaluate their role in the pathophysiology of nasal hypereosinophilia.

METHODS

The study was an analytic cross-section study, level of evidence 3b. Patients (n = 80) with nasal hypereosinophilia were randomly recruited and grouped in the following categories: persistent allergic rhinitis (AR) (n = 25), nonallergic rhinitis with eosinophilia syndrome (NARES) (n = 30), and chronic rhinosinusitis with polyps (CRSwNP) (n = 25). Non-rhinitic volunteers (n = 20) were recruited as controls. CCL24 and CCL26 concentrations were measured by enzyme-linked immunosorbent assay (ELISA) Quantikine Human Immunoassays (R&D Systems, Minneapolis, MN) in nasal lavage fluids. Differential cell counts were performed by microscopic cytological examination of nasal tissue scraped from the inferior turbinate.

RESULTS

Mean CCL26 levels were significantly higher (p < 0.05) in AR and in NARES (132.0 pg/mL and 187.63 pg/mL, respectively) than in the control group (13.5 pg/mL); in patients with CRSwNP, CCL26 values were increased compared to controls even though the difference was not statistically significant (58.9 pg/mL vs 16.5 pg/mL). Mean CCL24 levels measured in AR, NARES, and CRSwNP were significantly increased (p < 0.05) compared to controls (96.7 pg/mL, 135.4 pg/mL, and 107.0 pg/mL, respectively, vs 32.2 pg/mL). Moreover, we observed a significant correlation between CCL24 and CCL26 levels, evaluating them intraindividually by Spearman's rank correlation test. Finally, a significant correlation was found between CCL24 and CCL26 levels and the percentage of eosinophilic infiltration of nasal mucosa.

CONCLUSION

Our data suggest that CCL26 and CCL24 are likely involved in the pathogenesis of chronic nasal hypereosinophilia, with a complex cooperation and different involvement of the various members of eotaxin family. Further studies are necessary to better understand the actual physiopathologic mechanism, possible clinical relevance, and therapeutic implications.

Anti-inflammatory effects of polihexanide and polyethylene glycol in an in vitro study in chronic rhinosinusitis

The majority of patients affected by chronic rhinosinusitis (CRS) suffer from eosinophilic infiltration. We hypothesised that polihexanide and polyethylene glycol as an antiseptic might alter the eosinophil-associated IL-5 and eotaxin-3 expression in CRS and also the expression of MMP-9, being involved in the tissue-remodelling in CRS. After obtaining samples from 10 CRS patients with (CRSwNP) and without nasal-polyposis (CRSsNP) and 2 patients with inverted-papilloma undergoing functional endoscopic sinus surgery (FESS), the expression of interleukin-5, eotaxin-3 and MMP-9 were evaluated by an ELISA assay with and without the tested agent. CRSwNP showed a significantly increased expression of IL-5. Polihexanide seems not to alter the attraction of eosinophils in patients with CRS via IL-5 expression. Also elevated levels of MMP-9 could not be reduced to normal values. But there exists statistically significant evidence that the self-amplification process of eosinophils via eotaxin-3 could be influenced by the administration of polihexanide.

Omeprazole blocks eotaxin-3 expression by oesophageal squamous cells from patients with eosinophilic oesophagitis and GORD

OBJECTIVE

Eosinophilic oesophagitis (EoE) and gastro-oesophageal reflux disease (GORD) can have similar clinical and histological features. Proton pump inhibitors (PPIs) are used to distinguish the disorders, with the assumption that only GORD can respond to PPIs. Oesophageal expression of eotaxin-3 stimulated by Th2 cytokines might contribute to oesophageal eosinophilia in EoE. Th2 cytokine effects on the oesophagus in GORD are not known. The objective of the authors was to explore the molecular mechanisms of Th2 cytokines on eotaxin-3 expression by oesophageal squamous cells from patients with GORD and EoE, and the effects of omeprazole on that eotaxin-3 expression.

DESIGN

Using telomerase-immortalised and primary cultures of oesophageal squamous cells from GORD and EoE patients, the authors measured eotaxin-3 protein secretion stimulated by Th2 cytokines (interleukin (IL)-4 and IL-13). Eotaxin-3 promoter constructs were used to study transcriptional regulation. Cytokine-induced eotaxin-3 mRNA and protein expression were measured in the presence or absence of omeprazole.

RESULTS

There were no significant differences between EoE and GORD primary cells in cytokine-stimulated eotaxin-3 protein secretion levels. In EoE and GORD cell lines, IL-4 and IL-13 activated the eotaxin-3 promoter, and significantly increased eotaxin-3 mRNA and protein expression. Omeprazole blocked the cytokine-stimulated increase in eotaxin-3 mRNA and protein expression in EoE and GORD cell lines.

CONCLUSION

Oesophageal squamous cells from GORD and EoE patients express similar levels of eotaxin-3 when stimulated by Th2 cytokines, and omeprazole blocks that eotaxin-3 expression. These findings suggest that PPIs might have eosinophil-reducing effects independent of effects on acid reflux and that response to PPIs might not distinguish EoE from GORD.

Diagnostic utility of major basic protein, eotaxin-3, and leukotriene enzyme staining in eosinophilic esophagitis

OBJECTIVES

Features of eosinophilic esophagitis (EoE) and gastroesophageal reflux disease (GERD) overlap. We aimed to determine whether staining for tissue biomarkers would differentiate EoE from GERD, suggesting utility for diagnosis of EoE.

METHODS

In this case-control study, EoE patients defined by consensus guidelines were compared to GERD patients with eosinophils on esophageal biopsy. Immunohistochemistry was performed for major basic protein (MBP), eotaxin-3, leukotriene A4 hydrolase (LTA4H), and leukotriene C4 synthase (LTC4S). After masking, the maximum staining density (cells per mm(2)) was quantified for each marker and compared between groups. Receiver operator characteristic curves were constructed, and the area under the curve (AUC) calculated to assess the diagnostic utility of each of the biomarkers alone and in combination with eosinophil counts.

RESULTS

There were 51 EoE cases (mean age 24; mean 143 eosinophils per high-power field (eos per h.p.f.)) and 54 GERD controls (mean age 34; mean 20 eos per h.p.f.). The MBP density was higher in EoE than in GERD (1479 vs. 59 cells per mm(2); P<0.001), as was the eotaxin-3 density (2219 vs. 479; P<0.001). There were no differences for LTA4H and LTC4S. MBP density and eosinophil count correlated (R=0.81; P<0.001); correlation with eotaxin-3 was weaker (R=0.25; P=0.01). The AUC for diagnosis of EoE was 0.96 for MBP, 0.87 for eotaxin-3, 0.58 for LTA4H, 0.66 for LTC4S, and 0.99 for the combination of MBP, eotaxin-3, and eosinophil count.

CONCLUSIONS

Patients with EoE had substantially higher levels of MBP and eotaxin-3 staining than GERD patients. These markers may have utility as a diagnostic assay for EoE.