Eosinophilic oesophagitis and proton pump inhibitor-responsive oesophageal eosinophilia have similar clinical, endoscopic and histological findings.

BACKGROUND Some patients with a phenotypic appearance of eosinophilic oesophagitis (EoE) respond histologically to PPI, and are described as having PPI-responsive oesophageal eosinophilia (PPI-REE). It is unclear if PPI-REE is a GERD-related phenomenon, a subtype of EoE, or a completely unique entity. AIM To compare demographic, clinical and histological features of EoE and PPI-REE. METHODS Two databases were reviewed from the Walter Reed and Swiss EoE databases. Patients were stratified into two groups, EoE and PPI-REE, based on recent EoE consensus guidelines. Response to PPI was defined as achieving less than 15 eos/hpf and a 50% decrease from baseline following at least a 6-week course of treatment. RESULTS One hundred and three patients were identified (63 EoE and 40 PPI-REE; mean age 40.2 years, 75% male and 89% Caucasian). The two cohorts had similar dysphagia (97% vs. 100%, P = 0.520), food impaction (43% vs. 35%, P = 0.536), and heartburn (33% vs. 32%, P = 1.000) and a similar duration of symptoms (6.0 years vs. 5.8 years, P = 0.850). Endoscopic features were also similar between EoE and PPI-REE; rings (68% vs. 68%, P = 1.000), furrows (70% vs. 70%, P = 1.000), plaques (19% vs. 10%, P = 0.272), strictures (49% vs. 30%, P = 0.066). EoE and PPI-REE were similar in the number of proximal (39 eos/hpf vs. 38 eos/hpf, P = 0.919) and distal eosinophils (50 vs. 43 eos/hpf, P = 0.285). CONCLUSIONS EoE and PPI-responsive oesophageal eosinophilia are similar in clinical, histological and endoscopic features and therefore are indistinguishable without a PPI trial. Further studies are needed to determine why a subset of patients with oesophageal eosinophilia respond to PPI.

Stability of 3-bromotyrosine in serum and serum 3-bromotyrosine concentrations in dogs with gastrointestinal diseases

Abstract BACKGROUND: 3-Bromotyrosine (3-BrY) is a stable product of eosinophil peroxidase and may serve as a marker of eosinophil activation. A gas chromatography/mass spectrometry method to measure 3-BrY concentrations in serum from dogs has recently been established and analytically validated. The aims of this study were to determine the stability of 3-BrY in serum, to determine the association between peripheral eosinophil counts and the presence of an eosinophilic infiltrate in the gastrointestinal tract, and to compare serum 3-BrY concentrations in healthy dogs (n = 52) and dogs with eosinophilic gastroenteritis (EGE; n = 27), lymphocytic-plasmacytic enteritis (LPE; n = 25), exocrine pancreatic insufficiency (EPI; n = 26), or pancreatitis (n = 27). RESULTS: Serum 3-BrY concentrations were stable for up to 8, 30, and 180 days at 4°C, -20°C, and -80°C, respectively. There was no significant association between peripheral eosinophil count and the presence of eosinophils in the GI tissues (P = 0.1733). Serum 3-BrY concentrations were significantly higher in dogs with EGE (median [range] = 5.04 [≤0.63-26.26] μmol/L), LPE (median [range] = 3.60 [≤0.63-15.67] μmol/L), and pancreatitis (median [range] = 1.49 [≤0.63-4.46] μmol/L) than in healthy control dogs (median [range] = ≤0.63 [≤0.63-1.79] μmol/L; P < 0.0001), whereas concentrations in dogs with EPI (median [range] = 0.73 [≤0.63-4.59] μmol/L) were not different compared to healthy control dogs. CONCLUSIONS: The present study revealed that 3-BrY concentrations were stable in serum when refrigerated and frozen. No relationship between peripheral eosinophil count and the presence of eosinophils infiltration in the GI tissues was found in this study. In addition, serum 3-BrY concentrations were increased in dogs with EGE, but also in dogs with LPE and pancreatitis. Further studies are needed to determine whether measurement of 3-BrY concentrations in serum may be useful to assess patients with suspected or confirmed EGE or LPE.

Toxicity of eosinophil MBP is repressed by intracellular crystallization and promoted by extracellular aggregation.

Eosinophils are white blood cells that function in innate immunity and participate in the pathogenesis of various inflammatory and neoplastic disorders. Their secretory granules contain four cytotoxic proteins, including the eosinophil major basic protein (MBP-1). How MBP-1 toxicity is controlled within the eosinophil itself and activated upon extracellular release is unknown. Here we show how intragranular MBP-1 nanocrystals restrain toxicity, enabling its safe storage, and characterize them with an X-ray-free electron laser. Following eosinophil activation, MBP-1 toxicity is triggered by granule acidification, followed by extracellular aggregation, which mediates the damage to pathogens and host cells. Larger non-toxic amyloid plaques are also present in tissues of eosinophilic patients in a feedback mechanism that likely limits tissue damage under pathological conditions of MBP-1 oversecretion. Our results suggest that MBP-1 aggregation is important for innate immunity and immunopathology mediated by eosinophils and clarify how its polymorphic self-association pathways regulate toxicity intra- and extracellularly.

Active eosinophilic esophagitis is characterized by epithelial barrier defects and eosinophil extracellular trap formation.

BACKGROUND Eosinophilic esophagitis (EoE) exhibits esophageal dysfunction owing to an eosinophil-predominant inflammation. Activated eosinophils generate eosinophil extracellular traps (EETs) able to kill bacteria. There is evidence of an impaired barrier function in EoE that might allow pathogens to invade the esophagus. This study aimed to investigate the presence and distribution of EETs in esophageal tissues from EoE patients and their association with possible epithelial barrier defects. METHODS Anonymized tissue samples from 18 patients with active EoE were analyzed. The presence of DNA nets associated with eosinophil granule proteins forming EETs and the expression of filaggrin, the protease inhibitor lympho-epithelial Kazal-type-related inhibitor (LEKTI), antimicrobial peptides, and cytokines were evaluated by confocal microscopy following immune fluorescence staining techniques. RESULTS Eosinophil extracellular trap formation occurred frequently and was detected in all EoE samples correlating with the numbers of infiltrating eosinophils. While the expression of both filaggrin and LEKTI was reduced, epithelial antimicrobial peptides (human beta-defensin-2, human beta-defensin-3, cathelicidin LL-37, psoriasin) and cytokines (TSLP, IL-25, IL-32, IL-33) were elevated in EoE as compared to normal esophageal tissues. There was a significant correlation between EET formation and TSLP expression (P = 0.02) as well as psoriasin expression (P = 0.016). On the other hand, a significant negative correlation was found between EET formation and LEKTI expression (P = 0.016). CONCLUSION Active EoE exhibits the presence of EETs. Indications of epithelial barrier defects in association with epithelial cytokines are also present which may have contributed to the activation of eosinophils. The formation of EETs could serve as a firewall against the invasion of pathogens.

A novel regulatory macrophage induced by a helminth molecule instructs IL-10 in CD4+ T cells and protects against mucosal inflammation

Immunomodulation is a common feature of chronic helminth infections and mainly attributed to the secretion of bioactive molecules, which target and modify host immune cells. In this study, we show that the helminth immunomodulator AvCystatin, a cysteine protease inhibitor, induces a novel regulatory macrophage (Mreg; AvCystatin-Mreg), which is sufficient to mitigate major parameters of allergic airway inflammation and colitis in mice. A single adoptive transfer of AvCystatin-Mreg before allergen challenge suppressed allergen-specific IgE levels, the influx of eosinophils into the airways, local and systemic Th2 cytokine levels, and mucus production in lung bronchioles of mice, whereas increasing local and systemic IL-10 production by CD4(+) T cells. Moreover, a single administration of AvCystatin-Mreg during experimentally induced colitis strikingly reduced intestinal pathology. Phenotyping of AvCystatin-Mreg revealed increased expression of a distinct group of genes including LIGHT, sphingosine kinase 1, CCL1, arginase-1, and costimulatory molecules, CD16/32, ICAM-1, as well as PD-L1 and PD-L2. In cocultures with dendritic cells and CD4(+) T cells, AvCystatin-Mreg strongly induced the production of IL-10 in a cell-contact-independent manner. Collectively, our data identify a specific suppressive macrophage population induced by a single parasite immunomodulator, which protects against mucosal inflammation.

Eosinophilia in Dermatologic Disorders

Eosinophil infiltration can be observed in skin disorders, such as allergic/immunologic, autoimmune, infectious, and neoplastic diseases. Clinical presentations are variable and include eczematous, papular, urticarial, bullous, nodular, and fibrotic lesions; pruritus is a common symptom in all. In this review, we present representative eosinophilic skin diseases according to their clinical pattern, together with histologic findings and diagnostic procedures. We also discuss the potential roles of eosinophils in the pathogenesis of dermatologic disorder. Current pathogenesis-based diagnostic and therapeutic approaches are outlined.

Symptoms Have Modest Accuracy in Detecting Endoscopic and Histologic Remission in Adults With Eosinophilic Esophagitis.

BACKGROUND & AIMS It is not clear whether symptoms alone can be used to estimate the biologic activity of eosinophilic esophagitis (EoE). We aimed to evaluate whether symptoms can be used to identify patients with endoscopic and histologic features of remission. METHODS Between April 2011 and June 2014, we performed a prospective, observational study and recruited 269 consecutive adults with EoE (67% male; median age, 39 years old) in Switzerland and the United States. Patients first completed the validated symptom-based EoE activity index patient-reported outcome instrument and then underwent esophagogastroduodenoscopy with esophageal biopsy collection. Endoscopic and histologic findings were evaluated with a validated grading system and standardized instrument, respectively. Clinical remission was defined as symptom score <20 (range, 0-100); histologic remission was defined as a peak count of <20 eosinophils/mm(2) in a high-power field (corresponds to approximately <5 eosinophils/median high-power field); and endoscopic remission as absence of white exudates, moderate or severe rings, strictures, or combination of furrows and edema. We used receiver operating characteristic analysis to determine the best symptom score cutoff values for detection of remission. RESULTS Of the study subjects, 111 were in clinical remission (41.3%), 79 were in endoscopic remission (29.7%), and 75 were in histologic remission (27.9%). When the symptom score was used as a continuous variable, patients in endoscopic, histologic, and combined (endoscopic and histologic remission) remission were detected with area under the curve values of 0.67, 0.60, and 0.67, respectively. A symptom score of 20 identified patients in endoscopic remission with 65.1% accuracy and histologic remission with 62.1% accuracy; a symptom score of 15 identified patients with both types of remission with 67.7% accuracy. CONCLUSIONS In patients with EoE, endoscopic or histologic remission can be identified with only modest accuracy based on symptoms alone. At any given time, physicians cannot rely on lack of symptoms to make assumptions about lack of biologic disease activity in adults with EoE. ClinicalTrials.gov, Number: NCT00939263.

A new eosinophilic esophagitis (EoE)-like disease without tissue eosinophilia found in EoE Families

BACKGROUND Eosinophilic esophagitis (EoE) is a rapidly emerging, chronic inflammatory, genetically impacted disease of the esophagus, defined clinically by symptoms of esophageal dysfunction and, pathologically, by an eosinophil-predominant tissue infiltration. However, in four EoE-families, we have identified patients presenting with EoE-typical and corticosteroid-responsive symptoms, but without tissue eosinophilia. It was the aim of this study to clinically and immunologically characterize these patients with EoE-like disease. METHODS Five patients suffering from an EoE-like disease were evaluated with endoscopic, histologic, functional and quantitative immunohistologic examinations, and mRNA expression determination. RESULTS The frequency of first generation offspring of EoE-like disease patients affected by EoE or EoE-like disease was 40%. Immunofluorescence analysis confirmed an almost complete absence of eosinophils in the esophageal tissues of patients with EoE-like disease, but revealed a considerable T cell infiltration, comparable to EoE. In contrast to EoE, eotaxin-3 mRNA and protein were markedly reduced in EoE-like disease (P < 0.05). The mRNA expression levels of three selected EoE genes (eotaxin-3, MUC4 and CDH26) allowed to discriminate between EoE-like disease, EoE and normal epithelium. CONCLUSIONS Patients suffering from "EoE without eosinophilia" do not fulfill formally the diagnostic criteria for EoE. However, their clinical manifestation, immunohistology and gene-expression pattern, plus the fact that they bequeath EoE to their offspring, suggest a uniform underlying pathogenesis. Conventional EoE, with its prominent eosinophilia, therefore appears to be only one phenotype of a broader "inflammatory dysphagia syndrome" spectrum. In this light, the role of the eosinophils, the definition of EoE, and its diagnostic criteria must likely be reconsidered. This article is protected by copyright. All rights reserved.