Allergic components of eosinophilic esophagitis

The oral microbiome and oral and upper gastrointestinal diseases

Background

Microbiomes are essential components of the human body, and their populations are substantial. Under normal circumstances, microbiomes coexist harmoniously with the human body, but disturbances in this equilibrium can lead to various diseases. The oral microbiome is involved in the occurrence and development of many oral and gastrointestinal diseases. This review focuses on the relationship between oral microbiomes and oral and upper gastrointestinal diseases, and therapeutic strategies aiming to provide valuable insights for clinical prevention and treatment.

Methods

To identify relevant studies, we conducted searches in PubMed, Google Scholar, and Web of Science using keywords such as "oral microbiome," "oral flora, " "gastrointestinal disease, " without any date restrictions. Subsequently, the retrieved publications were subject to a narrative review.

Results

In this review, we found that oral microbiomes are closely related to oral and gastrointestinal diseases such as periodontitis, dental caries, reflux esophagitis, gastritis, and upper gastrointestinal tumors (mainly the malignant ones). Oral samples like saliva and buccal mucosa are not only easy to collect, but also display superior sample stability compared to gastrointestinal tissues. Consequently, analysis of the oral microbiome could potentially serve as an efficient preliminary screening method for high-risk groups before undergoing endoscopic examination. Besides, treatments based on the oral microbiomes could aid early diagnosis and treatment of these diseases.

Conclusions

Oral microbiomes are essential to oral and gastrointestinal diseases. Therapies centered on the oral microbiomes could facilitate the early detection and management of these conditions.

Clinical Evaluation of the Child with Eosinophilic Esophagitis

The diagnosis of eosinophilic esophagitis (EoE) is based on clinical symptoms of esophageal dysfunction and eosinophil predominant esophageal inflammation. Clinical symptoms in children with EoE vary based on age and may be nonspecific. EoE has a male predominance with the majority having comorbid atopic disorders. At present, treatment options include medications (proton pump inhibition, swallowed topical steroids), dietary therapy or biologic therapy (dupilumab, approved for those ≥12 years of age). Outside of EoE in the context of oral immunotherapy, EoE is typically chronic requiring lifelong therapy. Long-term complications including feeding difficulties, malnutrition, and fibrostenotic disease.

Pathophysiology of Eosinophilic Esophagitis

Eosinophilic esophagitis (EoE) is a chronic, progressive immune-mediated disease associated with antigen-driven type 2 inflammation and symptoms of esophageal dysfunction. Research over the last 2 decades has dramatically furthered our understanding of the complex interplay between genetics, environmental exposures, and cellular and molecular interactions involved in EoE. This review provides an overview of our current understanding of EoE pathogenesis.

Sublingual immunotherapy for cedar pollinosis possibly triggers eosinophilic esophagitis

Sublingual immunotherapy (SLIT) is an effective and popular treatment for cedar pollinosis. Although SLIT can cause allergic side effects, eosinophilic esophagitis (EoE) is a lesser-known side effect of SLIT. A 26-year-old male with cedar pollinosis, wheat-dependent exercise-induced anaphylaxis, and food allergies to bananas and avocados presented with persistent throat itching, difficulty swallowing, heartburn, and anterior chest pain 8 days after starting SLIT for cedar pollinosis. Laboratory examination showed remarkably elevated eosinophils, and esophagogastroduodenoscopy revealed linear furrows in the entire esophagus. Histological examination of an esophageal biopsy specimen revealed high eosinophil levels. The patient was strongly suspected with EoE triggered by SLIT. The patient was advised to switch from the swallow to the spit method for SLIT, and the symptoms associated with SLIT-triggered EoE were reduced after switching to the spit method. This case highlights the importance of recognizing SLIT-triggered EoE as a potential side effect of SLIT for cedar pollinosis, especially with the increasing use of SLIT in clinical practice. EoE can occur within a month after initiating SLIT in patients with multiple allergic conditions, as observed in our case. Furthermore, the spit method should be recommended for patients who experience SLIT-triggered EoE before discontinuing SLIT.

Interferon-γ signaling in eosinophilic esophagitis has implications for epithelial barrier function and programmed cell death

Objective

Eosinophilic esophagitis (EoE) is a chronic esophageal inflammatory disorder characterized by eosinophil-rich mucosal inflammation and tissue remodeling. Transcriptional profiling of esophageal biopsies has previously revealed upregulation of type I and II interferon (IFN) response genes. We aim to unravel interactions between immune and epithelial cells and examine functional significance in esophageal epithelial cells.

Design

We investigated epithelial gene expression from EoE patients using single-cell RNA sequencing and a confirmatory bulk RNA-sequencing experiment of isolated epithelial cells. The functional impact of interferon signaling on epithelial cells was investigated using in vitro organoid models.

Results

We observe upregulation of interferon response signature genes (ISGs) in the esophageal epithelium during active EoE compared to other cell types, single-cell data, and pathway analyses, identified upregulation in ISGs in epithelial cells isolated from EoE patients. Using an esophageal organoid and air-liquid interface models, we demonstrate that IFN-γ stimulation triggered disruption of esophageal epithelial differentiation, barrier integrity, and induced apoptosis via caspase upregulation. We show that an increase in cleaved caspase-3 is seen in EoE tissue and identify interferon gamma (IFNG) expression predominantly in a cluster of majority-CD8+ T cells with high expression of CD69 and FOS.

Conclusion

These findings offer insight into the interplay between immune and epithelial cells in EoE. Our data illustrate the relevance of several IFN-γ-mediated mechanisms on epithelial function in the esophagus, which have the potential to impact epithelial function during inflammatory conditions.

Reduction of Th2 inflammation and fibrosis in eosinophilic esophagitis in a murine model by citri reticulatae pericarpium

ETHNOPHARMACOLOGICAL RELEVANCE

Inflammation and subepithelial fibrosis play major roles in the early pathology of eosinophilic esophagitis (EoE). However, there are currently no pharmacotherapeutic interventions that directly target eosinophilic esophagitis. Citri Reticulatae Pericarpium (CRP, known as Chen-Pi) is one of most frequently used qi-regulating drugs in Chinese medicine and nutrition. CRP is rich with flavonones and polymethoxy flavones, both of which exhibit superior anti-inflammatory, anti-allergic and anti-fibrosis effects. This study is to investigate intervention effect of CRP on EoE, to identify its active compounds and to explore its underlying mechanisms.

METHODS

The CRP extract was obtained by liquid-liquid extraction with 70% ethanol, and its main components were identified by HPLC and TLC chromatography as hesperidin, nobiletin, tangeretin, and narirutin in turn. Furthermore, we evaluated its effect and underlying mechanisms in an PN (Peanut protein extract)-sensitized murine model of food allergy induced EoE.

RESULTS

CRP treatment attenuated EoE model mice symptomatology, blocked hypothermia, reduced the production of PN-specific IgE and IgG1 and TH2 cytokines (interleukin (IL)-4 and IL-5), and increased the level of anti-inflammatory cytokines IL-10 and interferon (IFN)-γ. CRP treatment also significantly alleviated the pathological damage and reduced fibrosis in inflamed tissues like esophagus, lung, and intestine. These results were strongly associated with reducing the expression of p-p38 mitogen-activated protein kinase (MAPK), transforming growth factor beta1 (TGF-β1) and p-Smad 3 proteins.

CONCLUSION

CRP extract markedly inhibited TH2 immune response and attenuated subepithelial fibrosis with a dose-dependent manner through down-regulating MAPK/TGF-β signaling pathway. It is suggested that CRP extract might serve as a potential therapy for food allergy-induced EoE like disease.

Global Incidence and Prevalence of Eosinophilic Esophagitis, 1976-2022: A Systematic Review and Meta-analysis

BACKGROUND AND AIMS

Owing to 2018 expanded diagnostic criteria for eosinophilic esophagitis (EoE) and thus a possible increase in diagnosis, previous studies on the global incidence and prevalence of EoE may need to be updated. We aimed to describe global, regional, and national trends in the incidence and prevalence of EoE from 1976 to 2022 and analyze their associations with geographic, demographic, and social factors through a systematic review.

METHODS

We searched the PubMed/MEDLINE, Embase, CINAHL, Google Scholar, and Cochrane databases from their inception dates to December 20, 2022, for studies that reported the incidence or prevalence of EoE in the general population. We calculated the global incidence and prevalence of EoE using pooled estimates with 95% confidence intervals (CIs) and performed subgroup analysis based on age, sex, race, geographical area, World Bank income group, and diagnostic criteria of EoE.

RESULTS

Forty studies met the eligibility criteria, including over 288 million participants and 147,668 patients with EoE from 15 countries across the five continents. The global pooled incidence and prevalence of EoE were 5.31 cases per 100,000 inhabitant-years (95% CI, 3.98-6.63; number of studies, 27; sample population, 42,191,506) and 40.04 cases per 100,000 inhabitant-years (95% CI, 31.10-48.98; number of studies, 20; sample population, 30,467,177), respectively. The pooled incidence of EoE was higher in high-income countries (vs low- or middle-income countries), males, and North America (vs Europe and Asia). The global prevalence of EoE followed a similar pattern. The pooled prevalence of EoE gradually increased from 1976 to 2022 (1976-2001; 8.18; 95% CI, 3.67-12.69 vs 2017-2022; 74.42; 95% CI, 39.66-109.19 cases per 100,000 inhabitant-years).

CONCLUSIONS

The incidence and prevalence of EoE have increased substantially and vary widely across the world. Further research is needed to evaluate the incidence and prevalence of EoE in Asia, South America, and Africa.

Eosinophilic Esophagitis Histologic Scoring System: Correlation with Histologic, Endoscopic, and Symptomatic Disease and Clinical Use

BACKGROUND

The eosinophilic esophagitis histologic scoring system (EoEHSS) was developed to enhance the diagnostic standard of peak eosinophil count (PEC) in evaluating disease activity in EoE.

AIMS

(1) Correlate the EoEHSS and PEC to measures of symptomatic and endoscopic disease activity, (2) Correlate EoEHSS grade and stage subcomponents to clinical, radiology, and endoscopic markers of fibrotic disease, (3) Evaluate EoEHSS remission in asymptomatic patients with PEC < 15 eosinophils per high powered field (eos/hpf).

METHODS

Secondary analysis of prospective cohort data of 22 patients with EoE that underwent dietary therapy and endoscopy at 3 time points. Active disease was defined by EoEHSS grade or stage > 0.125, symptomatic disease by EoE symptom activity index > 20, endoscopic disease by endoscopic reference score > 2, and histologic disease by PEC ≥ 15 eos/hpf. EoEHSS remission was defined by esophageal inflammation (EI) grade of 0-1, EI stage of 0, total grade ≤ 3, and total stage ≤ 3.

RESULTS

EoEHSS grade and stage did not correlate with symptomatic disease but did with endoscopic and histologic disease. PEC showed similar correlation pattern. Abnormal grade and stage had strong sensitivity (87-100%) but poor specificity (11-36%) to detect symptomatic, endoscopic, and histologic disease activity. Lamina propria fibrosis was evaluated in 36% of biopsies and did not correlate with minimum esophageal diameter. Out of 14 patients who were in complete symptomatic, endoscopic, and histologic remission, 8 met criteria for EoEHSS remission.

CONCLUSION

The positive and negative correlations of EoEHSS to specific measures of symptomatic, histologic, and endoscopic activity suggest that it provides complementary information in EoE.

A case of food and aeroallergen sublingual immunotherapy inducing eosinophilic esophagitis

Eosinophilic esophagitis (EoE) has been reported secondary to aeroallergen sublingual immunotherapy (SLIT) and food allergen oral immunotherapy. Gastrointestinal symptoms with food allergen SLIT are uncommon, with no prior reports of cases of food allergen SLIT inducing EoE. Here we report a patient who developed EoE secondary to food and aeroallergen SLIT therapy that resolved with SLIT cessation.

Recent Trends in the Management of Eosinophilic Esophagitis: A Systematic Review

Eosinophilic esophagitis (EoE) is a chronic immune-mediated condition characterized by inflammation and eosinophilic accumulation of the esophagus, resulting in dysphagia and food impaction. While the exact etiology of EoE remains unclear, it is believed to be triggered by food allergens and dynamic environmental factors, resulting in various clinical manifestations, from inflammation to fibrosis. Although clinical presentation varies with age, the number of eosinophils in esophagogastroduodenal endoscopy remains the diagnostic gold standard. While diet elimination, proton pump inhibitors (PPIs), topical corticosteroids, and biological therapy are promising treatment options for EoE, there are insufficient data to determine the optimal therapeutic treatment approach. Combination therapies - the use of dietary therapies in conjunction with other treatment modalities, such as PPIs, topical corticosteroids, or biologic agents - have also emerged as a potential management strategy for EoE. In this systematic review, we attempt to highlight the recent advances in EoE therapies and provide updated guidance to their management. From 2017 to 2022, we conducted a comprehensive electronic search of PubMed (MEDLINE) using specific keywords related to our objective and eventually included a total of 44 articles.

Food allergy: cause or consequence of pediatric eosinophilic esophagitis? Potential implications of ultraprocessed foods in prevention and management

Eosinophilic esophagitis (EoE) is a chronic, immune-mediated disease characterized by eosinophilic infiltration, leading to esophageal dysfunction, inflammation, and fibrotic remodeling. In the last few decades, there has been an increased prevalence of EoE at an alarming rate in the pediatric age. The pathogenesis of EoE is still largely undefined, and this limits the definition of effective strategies for the prevention and management of this condition. EoE is considered a multifactorial disease arising from a negative interaction between environmental factors and genetic background, causing an impaired esophageal epithelial barrier with subsequent abnormal allergen exposure activating type 2 (Th2) inflammation. Food antigens have been suggested as key players in Th2 inflammation in pediatric patients with EoE, but emerging evidence suggests a potential role of other dietary factors, including ultraprocessed foods, as possible triggers for the occurrence of EoE. In this paper, we discuss the potential role of these dietary factors in the development of the disease, and we propose a new approach for the management of pediatric patients with EoE.

Food Allergy Characteristics Associated With Coexisting Eosinophilic Esophagitis in FARE Registry Participants

BACKGROUND

Eosinophilic esophagitis (EoE) can coexist in individuals with food allergy.

OBJECTIVE

To evaluate the characteristics of food-allergic patients with and without coexisting EoE using a large food allergy patient registry.

METHODS

Data were derived from 2 Food Allergy Research & Education, Inc, Patient Registry surveys. A series of multivariable regression models were used to evaluate associations between demographic, comorbidity, and food allergy characteristics and the likelihood of reporting EoE.

RESULTS

Five percent (n = 309) of registry participants (n = 6074; ages <1 year->80 years, mean, 20.20 ± 15.37 years) reported having EoE. The odds of having EoE were significantly greater in male participants (adjusted odds ratio [aOR], 1.3; 95% CI, 1.04-1.72) and those with comorbid asthma (aOR, 2.0; 95% CI, 1.55-2.49), allergic rhinitis (aOR, 1.8; 95% CI, 1.37-2.22), oral allergy syndrome (aOR, 2.8; 95% CI, 2.09-3.70), food protein-induced enterocolitis syndrome (aOR, 2.5; 95% CI, 1.34-4.84), and hyper-IgE syndrome (aOR, 7.6; 95% CI, 2.93-19.92), though not atopic dermatitis (aOR, 1.3; 95% CI, 0.99-1.59), when adjusting for demographics (sex, age, race, ethnicity, and geographic location). Those with a greater number of food allergies (aOR, 1.3; 95% CI, 1.23-1.32), more frequent food-related allergic reactions (aOR, 1.2; 95% CI, 1.11-1.24), previous anaphylaxis (aOR, 1.5; 95% CI, 1.15-1.83), and health care utilization for food-related allergic reactions (aOR, 1.3; 95% CI, 1.01-1.67)-specifically intensive care unit admission (aOR, 1.2; 95% CI, 1.07-1.33)-were more likely to have EoE after controlling for demographics. However, no significant difference in ever using epinephrine for food-related allergic reactions was detected.

CONCLUSIONS

These self-reported data showed that coexisting EoE is associated with an increased number of food allergies, food-related allergic reactions per year, and measures of reaction severity, calling attention to the likely increased health care needs of food-allergic patients with EoE.

Characterization of a group of children with eosinophilic esophagitis in Cali, Colombia

PURPOSE

Eosinophilic esophagitis (EoE) is an immunologically mediated chronic disease of the gastrointestinal tract. The objective of this study was to clinically and demographically describe a child population with EoE diagnosed in a high-complexity hospital in Cali, Colombia.

METHODS

A retrospective study was carried out. The clinical histories of patients between 0 and 18 years with clinical suspicion and a histological diagnosis of EoE were analyzed. All patients underwent an allergy study, either by measurement of specific immunoglobulin (Ig) E and/or an intraepidermal skin-prick test.

RESULTS

Thirty-five patients were included in the study, of which 21 (60%) women. The median age was 8 years (interquartile range [IQR] 5-12), and the age of onset of symptoms was 5 years (IQR 2-10). Thirty patients (85.7%) reported a history of allergic disease, with rhinitis being the most frequent (n = 25, 71.4%). Only one patient reported with food allergy mediated by IgE. The main symptoms in patients included abdominal pain (17 [48.6%]), refractory gastroesophageal reflux (16 [45.7%]), and choking (9 [25.7%]). Upper gastrointestinal endoscopy was normal in 10 patients (38.5%). The median number of eosinophils in the biopsy was 42 (IQR 31-92). Allergenic sensitization was verified in 25 of 35 patients (71.4%). Of these, dust mite allergy was positive in 21 patients (84%), while the most frequent food allergy was toward cow's milk, in five patients (31.3%).

CONCLUSIONS

The majority of patients with EoE were females. The most frequent symptom was abdominal pain. Endoscopic abnormalities were also observed frequently, and the prevalence of other allergic diseases (especially rhinitis) and allergenic sensitization (especially to mites) was high.

Development of an Oral Isoliquiritigenin Self-Nano-Emulsifying Drug Delivery System (ILQ-SNEDDS) for Effective Treatment of Eosinophilic Esophagitis Induced by Food Allergy

Isoliquiritigenin (ILQ) is a natural flavonoid with various pharmacological activities. In this study, we optimized the preparation method of self-nano-emulsion-loaded ILQ to further improve its bioavailability based on our previous study. In addition, its effect on the treatment of eosinophilic esophagitis was also evaluated. Combined surfactants and co-surfactants were screened, and the optimal formulation of ILQ-SNEDDS was determined according to droplet size, droplet dispersity index (DDI), and drug loading. The formulation was composed of ethyl oleate (oil phase), Tween 80 & Cremophor EL (surfactant, 7:3), and PEG 400 & 1,2-propylene glycol (cosurfactant, 1:1), with a mass ratio of 3:6:1. Its physicochemical properties, including drug loading, droplets' size, Zeta potential, appearance, and Fourier transform infrared (FTIR) spectroscopy, were characterized. In vitro release profile, in situ intestinal absorption, and in vivo pharmacokinetics were applied to confirm the improvement of oral ILQ bioavailability by NEDDS. Finally, the efficacy of ILQ-SNEDDS in the treatment of food allergy-induced eosinophilic esophagitis (EOE) was further evaluated. When the ILQ drug loading was 77.9 mg/g, ILQ-SNEDDS could self-assemble into sub-spherical uniform droplets with an average size of about 33.4 ± 2.46 nm (PDI about 0.10 ± 0.05) and a Zeta potential of approximately -10.05 ± 3.23 mV. In situ intestinal absorption showed that optimized SNEDDS significantly increased the apparent permeability coefficient of ILQ by 1.69 times, and the pharmacokinetic parameters also confirmed that SNEDDS sharply increased the max plasma concentration and bioavailability of ILQ by 3.47 and 2.02 times, respectively. ILQ-SNEDDS also significantly improved the apparent signs, allergic index, hypothermia and body weight of EoE model mice. ILQ-SNEDDS treatment significantly reduced the levels of inflammatory cytokines, such as TNF-α, IL-4, and IL-5, and the level of PPE-s-IgE in serum, and significantly inhibited the expression of TGF-β1 in esophageal tissue. SNEDDS significantly improved the solubility and bioavailability of ILQ. Additionally, ILQ-SNEDDS treatment attenuated symptomatology of EoE model mice, which was associated with inhibiting the production of T_H2 inflammatory cytokines and PPE-s-IgE and the expression of TGF-β1. The above results shows that ILQ-SNEDDS has great potential as a good candidate for the treatment of eosinophilic esophagitis.

Refractory eosinophilic esophagitis: what to do when the patient has not responded to proton pump inhibitors, steroids and diet

PURPOSE OF REVIEW

Management for patients with refractory eosinophilic esophagitis (EoE) remains a clinical challenge. This review aims to define refractory EoE, explore rates and reasons for nonresponse, and discuss the evidence that informs the approach to these patients.

RECENT FINDINGS

Many patients will fail first-line therapies for EoE. Longer duration of therapy can increase response rates, and initial nonresponders may respond to alternative first-line therapies. There are ongoing clinical trials evaluating novel therapeutics that hold promise for the future of EoE management. Increasingly, there is recognition of the contribution of oesophageal hypervigilance, symptom-specific anxiety, abnormal motility and oesophageal remodelling to ongoing clinical symptoms in patients with EoE.

SUMMARY

For refractory EoE, clinicians should first assess for adherence to treatment, adequate dosing and correct administration. Extending initial trials of therapy or switching to an alternative first-line therapy can increase rates of remission. Patients who are refractory to first-line therapy can consider elemental diets, combination therapy or clinical trials of new therapeutic agents. Patients with histologic remission but ongoing symptoms should be evaluated for fibrostenotic disease with EGD, barium esophagram or the functional luminal imaging probe (FLIP) and should be assessed for the possibility of oesophageal hypervigilance.

Sophoraflavanone G from Sophora flavescens Ameliorates Allergic Airway Inflammation by Suppressing Th2 Response and Oxidative Stress in a Murine Asthma Model

Sophoraflavanone G (SG), isolated from Sophora flavescens, has anti-inflammatory and anti-tumor bioactive properties. We previously showed that SG promotes apoptosis in human breast cancer cells and leukemia cells and reduces the inflammatory response in lipopolysaccharide-stimulated macrophages. We investigated whether SG attenuates airway hyper-responsiveness (AHR) and airway inflammation in asthmatic mice. We also assessed its effects on the anti-inflammatory response in human tracheal epithelial cells. Female BALB/c mice were sensitized with ovalbumin, and asthmatic mice were treated with SG by intraperitoneal injection. We also exposed human bronchial epithelial BEAS-2B cells to different concentrations of SG to evaluate its effects on inflammatory cytokine levels. SG treatment significantly reduced AHR, eosinophil infiltration, goblet cell hyperplasia, and airway inflammation in the lungs of asthmatic mice. In the lungs of ovalbumin-sensitized mice, SG significantly promoted superoxide dismutase and glutathione expression and attenuated malondialdehyde levels. SG also suppressed levels of Th2 cytokines and chemokines in lung and bronchoalveolar lavage samples. In addition, we confirmed that SG decreased pro-inflammatory cytokine, chemokine, and eotaxin expression in inflammatory BEAS-2B cells. Taken together, our data demonstrate that SG shows potential as an immunomodulator that can improve asthma symptoms by decreasing airway-inflammation-related oxidative stress.

Safety of the standardized quality tree sublingual immunotherapy tablet: Pooled safety analysis of clinical trials

BACKGROUND

The standardized quality (SQ) tree sublingual immunotherapy (SLIT)-tablet has recently been approved for treatment of tree pollen allergy. Healthcare workers should be provided with detailed safety data for clinical use.

OBJECTIVE

To assess the tolerability and safety of the SQ tree SLIT-tablet (12 SQ-Bet) in adults and adolescents.

METHODS

Safety data were pooled from three double-blinded, randomized, placebo-controlled trials (2 phase-II/1 phase-III) including adults and adolescents 12-65 years with allergic rhinitis and/or conjunctivitis treated before and during one pollen season once-daily with 12 SQ-Bet (n = 471) or placebo (n = 458): EudraCT no: 2012-000031-59; NCT02481856; EudraCT 2015-004821-15.

RESULTS

The most frequently reported investigational medicinal product (IMP)-related AEs with 12 SQ-Bet were oral pruritis (39% of subjects) and throat irritation (29%). IMP-related AEs were mainly mild or moderate in severity, and the majority resolved without treatment and did not lead to treatment interruption/discontinuation. With 12 SQ-Bet, oral pruritus was more frequent among subjects with pollen food syndrome (PFS) (45%) than without PFS (29%). The 12 SQ-Bet did not seem to induce an increased risk of asthma: 7 events were reported in 7 subjects with 12 SQ-Bet and 11 in 10 subjects with placebo. No differences were seen in the risk of moderate-to-severe IMP-related AEs regardless of age, PFS status and asthma medical history.

CONCLUSIONS

The 12 SQ tree SLIT-tablet was well tolerated in tree pollen allergic subjects with no major safety concerns detected. This safety profile supports daily at-home sublingual administration once the first dose is tolerated when administered under medical supervision.

Peripheral markers of allergen-specific immune activation predict clinical allergy in eosinophilic esophagitis

BACKGROUND

Eosinophilic esophagitis (EoE) is a T-cell-mediated disease that is caused by specific foods and results in esophageal dysfunction. Existing allergy testing modalities are not helpful when attempting to identify EoE-causal foods necessitating empiric food elimination and recurrent endoscopy. The goal of this study was to identify and compare allergen-specific immune features that can be assayed in a minimally invasive manner to predict clinical food allergy in EoE.

METHODS

We obtained blood samples from control subjects (n = 17), subjects with clinical EoE milk allergy (n = 17), and subjects with immunoglobulin E-mediated milk allergy (n = 9). We measured total and milk-specific plasma immunoglobulin G (IgG)4 levels and peripheral memory CD4⁺ T helper (T_H ) cell proliferation and cytokine production after stimulation with endotoxin-depleted milk proteins. Sensitivity and specificity for predicting clinical EoE milk allergy were calculated and compared between approaches.

RESULTS

Total and milk-specific IgG4 levels were not significantly different between control subjects and subjects with clinical EoE milk allergy. Stimulation with milk proteins caused T_H lymphocytes from subjects with clinical EoE milk allergy to proliferate more (%P1 of 38.3 ± 4.6 vs. 12.7 ± 2.8, p < 0.0001), and produce more type 2 cytokines (%IL-4⁺ of 33.7 ± 2.8 vs. 6.9 ± 1.6, p < 0.0001) than cells from control subjects. Milk-dependent memory T_H -cell proliferation (sensitivity and specificity of 88% and 82%, respectively) and interleukin 4 (IL-4) production (sensitivity and specificity of 100%) most strongly predicted clinical EoE milk allergy.

CONCLUSIONS

Peripheral markers of allergen-specific immune activation may be useful in identifying EoE-causal foods. Assaying milk-dependent IL-4 production by circulating memory T_H lymphocytes most accurately predicts clinical EoE milk allergy.

From Allergen Molecules to Molecular Immunotherapy of Nut Allergy: A Hard Nut to Crack

Peanuts and tree nuts are two of the most common elicitors of immunoglobulin E (IgE)-mediated food allergy. Nut allergy is frequently associated with systemic reactions and can lead to potentially life-threatening respiratory and circulatory symptoms. Furthermore, nut allergy usually persists throughout life. Whether sensitized patients exhibit severe and life-threatening reactions (e.g., anaphylaxis), mild and/or local reactions (e.g., pollen-food allergy syndrome) or no relevant symptoms depends much on IgE recognition of digestion-resistant class I food allergens, IgE cross-reactivity of class II food allergens with respiratory allergens and clinically not relevant plant-derived carbohydrate epitopes, respectively. Accordingly, molecular allergy diagnosis based on the measurement of allergen-specific IgE levels to allergen molecules provides important information in addition to provocation testing in the diagnosis of food allergy. Molecular allergy diagnosis helps identifying the genuinely sensitizing nuts, it determines IgE sensitization to class I and II food allergen molecules and hence provides a basis for personalized forms of treatment such as precise prescription of diet and allergen-specific immunotherapy (AIT). Currently available forms of nut-specific AIT are based only on allergen extracts, have been mainly developed for peanut but not for other nuts and, unlike AIT for respiratory allergies which utilize often subcutaneous administration, are given preferentially by the oral route. Here we review prevalence of allergy to peanut and tree nuts in different populations of the world, summarize knowledge regarding the involved nut allergen molecules and current AIT approaches for nut allergy. We argue that nut-specific AIT may benefit from molecular subcutaneous AIT (SCIT) approaches but identify also possible hurdles for such an approach and explain why molecular SCIT may be a hard nut to crack.

Zooming in on T cell clones: Are we heading to personalized treatment of allergy?

Single-cell RNA and TCR sequencing of peripheral blood and esophageal cells of human eosinophilic esophagitis uncovers antigen-restricted T_H2 cells.

Hydrolysed Formulas in the Management of Cow's Milk Allergy: New Insights, Pitfalls and Tips

An allergy to cow's milk requires the avoidance of cow's milk proteins and, in some infants, the use of a hypoallergenic formula. This review aims to summarize the current evidence concerning different types of hydrolysed formulas (HF), and recommendations for the treatment of IgE- and non-IgE-mediated cow's milk allergy and functional gastrointestinal disorders in infancy, for which some dietary intervention and HF may be of benefit to both immune and motor mechanisms. Current guidelines recommend cow's milk protein (i.e., whey or casein) extensively hydrolysed formula (eHF) as the first choice for cow's milk allergy treatment, and amino acid formulas for more severe cases or those with reactions to eHF. Rice hydrolysed formulas (rHF) have also become available in recent years. Both eHF and rHF are well tolerated by the majority of children allergic to cow's milk, with no concerns regarding body growth or adverse effects. Some hydrolysates may have a pro-active effect in modulating the immune system due to the presence of small peptides and additional components, like biotics. Despite encouraging results on tolerance acquisition, evidence is still not conclusive, thus hampering our ability to draw firm conclusions. In clinical practice, the choice of hypoallergenic formula should be based on the infant's age, the severity, frequency and persistence of symptoms, immune phenotype, growth pattern, formula cost, and in vivo proof of tolerance and efficacy.

Rising trend in p​ediatric eosinophilic esophagitis incidence in Spain: Results of a prospective study 2014-16

OBJECTIVES

The rate of eosinophilic esophagitis (EoE) diagnosis is increasing. This study aims to determine the incidence of EoE in the pediatric population residing in the southwestern Madrid and to analyze whether absolute monthly pollen counts, modified or not by the principal atmospheric pollutants, are associated with it.

METHODS

A cross-sectional study on prospectively recruited patients was designed to calculate the incidence of EoE in children aged under 15 years who were diagnosed between September 2014 and August 2016 in twelve hospitals. We collected demographic and symptoms data, date of onset of symptoms, date of medical consultation, and date of endoscopic diagnosis of each included patient. Relative risk estimation was performed to assess the association between the incidence of diagnosis and monthly pollen counts and levels of atmospheric pollutants. All these models were adjusted for the number of total patients that underwent endoscopy at first time.

RESULTS

One hundred forty-eight patients were included. The most frequent symptoms were abdominal pain [42.57%], dysphagia [42.57%], and impaction [39%-86%]. The median overall monthly incidence was 1.13 [interquartile rank: 0.97-1.43] cases/100,000 children, and the annual mean was 15.2. The overall analysis of the relationship between incidence and absolute monthly counts, corrected for the number of first-time endoscopies performed, revealed no statistically significant association with pollen and air pollutants. There was a higher frequency of diagnosis during the pollination period of Cupressaceae [relative risk 1.647; 95% CI (1.192-2.276) p < .002] and during February and November (relative risk 1.67; p < .01).

CONCLUSIONS

This study confirms the high incidence of eosinophilic esophagitis and also suggests a period of higher incidence of diagnosis in the months of February and November as well as in the period of high pollination of Cupressaceae.

Memory Generation and Re-Activation in Food Allergy

Recent evidence has highlighted the critical role of memory cells in maintaining lifelong food allergies, thereby identifying these cells as therapeutic targets. IgG+ memory B cells replenish pools of IgE-secreting cells upon allergen exposure, which contract thereafter due to the short lifespan of tightly regulated IgE-expressing cells. Advances in the detection and highly dimensional analysis of allergen-specific B and T cells from allergic patients have provided insight on their phenotype and function. The newly identified Th2A and Tfh13 populations represent a leap in our understanding of allergen-specific T cell phenotypes, although how these populations contribute to IgE memory responses remains poorly understood. Within, we discuss the mechanisms by which memory B and T cells are activated, integrating knowledge from human systems and fundamental research. We then focus on memory reactivation, specifically, on the pathways of secondary IgE responses. Throughout, we identify areas of future research which will help identify immunotargets for a transformative therapy for food allergy.

Lower esophageal sphincter muscle of patients with achalasia exhibits profound mast cell degranulation

BACKGROUND

Eosinophils and mast cells are key effectors of allergy. When they accumulate in the esophagus, their myoactive, pro-inflammatory, and cytotoxic products potentially could cause achalasia-like motility abnormalities and neuronal degeneration. We hypothesized that there is an allergy-mediated form of achalasia.

METHODS

LES muscle samples obtained during Heller myotomy from patients with achalasia or EGJ outflow obstruction (EGJOO) and from organ donor controls were immunostained for tryptase. Eosinophil and mast cell density, and mast cell degranulation were assessed. LES muscle was evaluated by qPCR for genes mediating smooth muscle Ca²⁺ handling and contraction.

KEY RESULTS

There were 13 patients (7 men, median age 59; 10 achalasia, 3 EGJOO) and 7 controls (4 men, median age 42). Eosinophils were infrequent in LES muscle, but mast cells were plentiful. Patients and controls did not differ significantly in LES mast cell density. However, 12 of 13 patients exhibited profound LES mast cell degranulation involving perimysium and myenteric plexus nerves, while only mild degranulation was seen in 2 of 7 controls. Hierarchical clustering analysis of qPCR data revealed two "mototype" LES gene expression patterns, with all type II patients in one mototype, and type I and III patients in the other.

CONCLUSIONS & INFERENCES

LES muscle of patients with achalasia or EGJOO exhibits striking mast cell degranulation, and patients with different achalasia manometric phenotypes exhibit different LES patterns of expression for genes mediating Ca²⁺ handling and muscle contraction. Although these findings are not definitive, they support our hypothesis that achalasia can be allergy-driven.

Classification of patients with esophageal eosinophilia by patterns of sensitization revealed by a diagnostic assay for multiple allergen-specific IgEs

BACKGROUND

Eosinophilic esophagitis (EoE) is considered to be an immunoglobulin E (IgE)-mediated allergic disorder. Our goal was to examine IgE-mediated allergic sensitization patterns in patients with esophageal eosinophilia (EE).

METHODS

We enrolled subjects with EE who underwent evaluation with a diagnostic panel to document multiple allergen-specific IgEs. Statistically significant groups were identified by cluster analysis. We also defined allergens based on their characteristics including outdoor, indoor, plant, and animal allergens.

RESULTS

We classified patients with EE into 3 distinct groups, including cluster 1 (n = 62) who were minimally sensitized to most allergens except pollen and house dust, cluster 2 (n = 30) who were hypersensitized to outdoor and plant allergens, and cluster 3 (n = 15) who were hypersensitized to most allergens, most notably to indoor and animal allergens. Dysphagia reported among those in clusters 1, 2, and 3 at 35.5%, 46.7%, and 73.3%, respectively, (p = 0.028) and EoE endoscopic reference scores (EREFS) at 3.0, 6.0, and 8.0, respectively, (p < 0.001) differed significantly between the 3 clusters. Those in cluster 3 had a significantly higher prevalence of dysphagia (35.5% vs. 73.3%, p = 0.030), and higher EREFS with respect to rings (0.3 vs. 0.9, p = 0.003) and strictures (0.0 vs. 0.13, p = 0.011) compared to those in cluster 1.

CONCLUSIONS

IgE-mediated allergic sensitization patterns are associated with clinical features of patients with EE. Use of a diagnostic panel that detects multiple allergen-specific IgEs can help to explain the heterogeneous phenotype of this patient cohort.

Validation of the diagnosis of eosinophilic esophagitis based on histopathology reports in Sweden

BACKGROUND

Eosinophilic esophagitis (EoE) is a relatively new diagnosis, where until recently a specific international classification of disease code was missing. One way to identify patients with EoE is to use histopathology codes. We validated the clinicopathological EoE diagnosis based on histopathology reports and patient charts to establish these data sources as the basis for a nationwide EoE patient cohort.

METHODS

Through the Epidemiology Strengthened by histoPathology Reports in Sweden (ESPRESSO) study, we randomly selected 165 patients from five Swedish health care regions with a histopathologic diagnosis of EoE. Patients were assigned a histopathology diagnosis of EoE if they had ≥15 eosinophils per high-power field or, in the absence of eosinophil quantification, the pathologist interpreted the biopsy as consistent with EoE. Patient charts were scrutinized to see if the other diagnostic criteria were fulfilled. Of the 131 received patient charts, 111 (85%) had sufficient information to be included in the study.

RESULTS

Of the 111 validated patients, 99 had EoE, corresponding to a positive predictive value of 89% (95% confidence interval = 82-94%). Dysphagia was the most common symptom (n = 78, 70%), followed by food impaction (n = 64, 58%) and feeding difficulties (n = 37, 33%). Twelve patients had coexisting asthma (11%) and 16 allergic rhinitis (14%). Seventeen patients underwent esophageal dilatation (15%), of which seven had more than one dilatation. Ninety-seven (87%) patients had a proton-pump inhibitor treatment ≤2 years before or after the diagnosis. Forty-two patients (38%) had been prescribed inhalation steroids and 64 (58%) had undergone esophageal radiology.

CONCLUSION

Histopathology reports from the ESPRESSO cohort with esophageal eosinophilic inflammation are suggestive of EoE.

The Role of Food Allergy in Eosinophilic Esophagitis

Food allergy is often understood as an IgE-mediated hypersensitivity, characterized by allergic symptoms which occur “immediately” after the ingestion of a relevant food allergen. Increasingly, however, other food-related immune-mediated disorders are recognized in which symptoms can have a delayed onset and IgE does not play a central role. One of the described examples of the latter is eosinophilic esophagitis (EoE) – a disease defined pathologically by local eosinophilic inflammation in the esophagus in the setting of symptoms of esophageal dysfunction. The evidence that EoE is a food-mediated allergic disease includes i) almost all patients respond to an elemental diet and many respond to a diet in which dairy, wheat, eggs and/or soy are eliminated, ii) the presence of food-specific IgE and Th2 cells are consistent with a loss of tolerance to trigger foods and iii) many EoE patients have concomitant IgE-mediated food allergy and other allergic co-morbidities. This narrative review focuses on the hypothesis that EoE is a form of chronic food allergy. The goal is to describe similarities and differences in EoE and IgE-mediated food allergy, and to consider ways that these two increasingly common forms of food allergy are related to each other.

Eosinophilic Esophagitis as a Side Effect of Food Oral Immunotherapy

Food allergies (FAs) include a spectrum of immune-mediated serious and potentially life-threatening medical conditions with an overall estimated prevalence ranging from 4% to 8% in the U.S. and Europe. Significant progress in food allergen-specific immunotherapy has been accomplished over the past 10 years. The most studied strategy has been oral immunotherapy (OIT), also known as food desensitization, a treatment in which a child is slowly and deliberately given a small amount of the food to ingest (that previously was a food allergy trigger) with the ultimate goal of the child eating that food without a reaction. OIT is now recommended in the European guidelines for the treatment of milk, egg, and peanut allergies and was the first American Food Drug Administration (FDA) approved product for the prevention of severe reaction to peanuts in 4–17 year olds to be released on the market. The side effects associated with OIT treatment trials are mild to moderate, predominantly oropharyngeal, and easily treated. More severe reactions, such as generalized urticaria/angioedema, wheezing/respiratory distress, laryngeal edema, and repetitive emesis, have been reported. However systemic reactions are very rare. Low-dose immunotherapy is associated with significantly fewer side effects. Currently, its most limiting allergic side effect is that approximately 10–15% of subjects treated with OIT experience gastrointestinal symptoms, preventing the continuation of therapy. Eosinophilic esophagitis (EoE) has also been reported as a cause of persistent abdominal symptoms in OIT.

Effectiveness of allergy testing in milk induced eosinophilic esophagitis. Description and follow-up of patients

INTRODUCTION

Eosinophilic esophagitis (EoE) is a chronic, local immune-mediated esophageal disease that has been on the increase lately. There is currently enough evidence to conclude that EoE is an allergic disorder triggered by food allergens, with cow's milk (CM) being the most frequent. Dietary intervention is the first-line approach. This study aimed to assess the clinical characteristics, the diagnostic method, and the prognosis of patients whose culprit food was CM, as opposed to other triggers.

METHODS

Children with EoE evaluated in our pediatric Allergy Department were retrospectively studied from 2004 to 2017. We collected clinical variables, diagnostic protocol, treatment, and follow-up data. We compared patients whose culprit food was CM and patients with EoE due to other causative agents.

RESULTS

We analyzed 31 children with EoE and found the causative food to be cow's milk in 14 (45%). Clinical characteristics were similar in patients with EoE due to milk or any other cause. Eight of 14 patients with milk-induced EoE (57.14%) presented positive skin prick test results against cow's milk. All patients had positive IgE against cow's milk. None of the patients had any other food as the trigger. The median follow-up was 2.68 years (6 months to 9 years) with initial remission of 100%.

CONCLUSION

Testing-based elimination diets effectively treated all of the patients with milk-induced EoE. The advantage of this diagnostic protocol is that it required a mean of only two foods to be tested, significantly smaller number than in empiric diets.

The Salivary Microbiome Is Altered in Children With Eosinophilic Esophagitis and Correlates With Disease Activity

Eosinophilic esophagitis (EoE) is an allergen-mediated inflammatory disease affecting the esophagus. Although microbial communities may affect the host immune responses, little is known about the role of the microbiome in EoE. We compared the composition of the salivary microbiome in children with EoE with that of non-EoE controls to test the hypotheses that the salivary microbiome is altered in children with EoE and is associated with disease activity.

Eosinophilic Esophagitis

Eosinophilic esophagitis (EoE) is a relatively new disease that has reached an incidence similar to that of Crohn disease and ulcerative colitis. With this increased presence, greater recognition is essential. This applies both to children with nonspecific but potentially debilitating symptoms and to adults who have spent years behaviorally compensating for narrow esophageal strictures. The pathogenesis of EoE is rapidly being unraveled and is based on initiation of a type II allergic response to specific food antigens, leading to dense esophageal eosinophilia, chronic inflammation, and esophageal fibrosis. With greater familiarity and understanding of EoE, treatments are evolving, including identification and avoidance of food antigens; broad applications of topical steroids; and, eventually, pathway-specific biologic therapy.

Strategy for Food Reintroduction Following Empiric Elimination and Elemental Dietary Therapy in the Treatment of Eosinophilic Gastrointestinal Disorders

PURPOSE OF REVIEW

This review presents the available data regarding efficacy of nutritional therapy, highlighting clinical decision points and a strategy for reintroduction of foods following an elemental diet for treatment of eosinophilic gastrointestinal disorders.

RECENT FINDINGS

Elemental and empiric elimination diets are highly effective treatments for eosinophilic gastrointestinal diseases. Standardization in the reintroduction phase, after utilizing the diet for disease remission, is lacking. Clinicians are confronted with multiple challenges regarding the best practice for food reintroduction and identification of potential dietary triggers including order of foods being challenged and duration between endoscopic procedures. Individualization is required for preference and adherence to optimize quality of life and treatment success for this burdensome and life altering immune driven gastrointestinal disorder. Age specific concerns for children, teenagers, and adults should be assessed using a patient centric approach.

Omeprazole inhibits IgE-mediated mast cell activation and allergic inflammation induced by ingested allergen in mice

BACKGROUND

Patients with eosinophilic esophagitis have increased numbers of mucosal mast cells. Administration of the proton pump inhibitor omeprazole can reduce both esophageal mast cell and eosinophil numbers and attenuate type 2 inflammation in these subjects.

OBJECTIVE

Given that maintenance of an acidic environment within granules is important for mast cell homeostasis, we sought to evaluate the effects of omeprazole on mast cell functions including development, IgE:FcεRI-mediated activation, and responses to food allergen.

METHODS

Mast cell degranulation, cytokine secretion, and early signaling events in the FcεRI pathway, including protein kinase phosphorylation and Ca²⁺ flux, were measured after IgE crosslinking in murine bone marrow-derived mast cells and human cord blood-derived mast cells. The effects of omeprazole on these responses were investigated as was its impact on mast cell-dependent anaphylaxis and food allergy phenotypes in vivo.

RESULTS

Murine and human mast cells treated with omeprazole exhibited diminished degranulation and release of cytokines and histamine in response to allergen. In murine mast cells, phosphorylation of protein kinases, ERK and SYK, was decreased. Differentiation of mast cells from bone marrow progenitors was also inhibited. IgE-mediated passive anaphylaxis was blunted in mice treated with omeprazole as was allergen-induced mast cell expansion and mast cell activation in the intestine in a model of food allergy.

CONCLUSIONS

Our findings suggest that omeprazole targets pathways important for the differentiation and activation of murine mast cells and for the manifestations of food allergy and anaphylaxis.

Approaches and Challenges to Management of Pediatric and Adult Patients With Eosinophilic Esophagitis

Treatment of eosinophilic esophagitis has progressed from elemental formula for children and esophageal dilation for adults to selective exclusion of food triggers and swallowed topical corticosteroids. Management guidelines are available from the American Gastroenterological Association and the Joint Task Force on Allergy Immunology Practice Parameters. We cannot, however, evaluate the efficacy of treatments without a definition of response. We propose a treat-to-target approach, based on symptoms and findings from endoscopy and histology. This approach addresses dissociations between outcomes, such as symptom persistence despite normalization of histologic features and symptom resolution after esophageal dilation despite histologic features of active disease. Eosinophilic esophagitis can now be treated with biologic agents that target specific immune pathways, and findings from prospective trials have indicated that less-restrictive, empiric, elimination diets can be effective and reduce the need for repeated endoscopic assessment of disease activity during food reintroduction. We also discuss eosinophilic esophagitis subtypes, factors associated with disease, and advances in management.

Hypersensitivity and adverse reactions to biologics for asthma and allergic diseases

Introduction: The development of new biologic agents has provided definite therapeutic advances but, like with any new medications, safety remains a concern.Areas covered: Using PubMed, we reviewed the literature on the adverse effects (AE) to five biologics approved for asthma and/or allergic diseases: one anti-IgE (omalizumab), three anti-IL5 (mepolizumab, reslizumab, benralizumab), and one anti-IL4 (dupilumab).Expert opinion: Biologic agents approved for asthma and allergic diseases are generally safe. Most common AE are benign and tolerated, though long-term safety is lacking for most of them. A slightly increased risk of anaphylaxis to omalizumab and reslizumab required the inclusion of a black box warning, informing the patient, the need for post-injection observation period, and the provision of epinephrine autoinjectors for self-administration when needed. Hypersensitivity reactions, mainly urticaria and very rarely serum sickness have occurred.

Non-IgE Mediated Food Allergy

Food allergies, defined as an immune response to food proteins, affect as many as 8% of young children and 2% of adults in western countries, and their prevalence appears to be rising like all allergic diseases. In addition to well-recognized urticaria and anaphylaxis triggered by IgE antibody- mediated immune responses, there is an increasing recognition of cell-mediated disorders, such as eosinophilic esophagitis and food protein-induced enterocolitis. Non-IgE-Mediated gastrointestinal food allergies are a heterogeneous group of food allergies in which there is an immune reaction against food but the primary pathogenesis is not a production of IgE and activation of mast cells and basophils. Those diseases tend to affect mainly the gastrointestinal tract and can present as acute (FPIES) or chronic reaction, such as Eosinophilic Esophagitis (EoE), Food Protein-Induced Allergic Proctocolitis (FPIAP). The role of food allergy in Non-EoE gastrointestinal Eosinophilic disorders (Non- EoE EGID) is poorly understood. In some diseases like EoE, T cell seems to play a major role in initiating the immunological reaction against food, however, in FPIES and FPIAP, the mechanism of sensitization is not clear. Diagnosis requires food challenges and/or endoscopies in most of the patients, as there are no validated biomarkers that can be used for monitoring or diagnosis of Non-IgE mediated food allergies. The treatment of Non-IgE food allergy is dependent on diet (FPIES, and EoE) and/or use of drugs (i.e. steroids, PPI) in EoE and Non-EoE EGID. Non-IgE mediated food allergies are being being investigated.

Diagnosis and treatment of eosinophilic esophagitis

Eosinophilic esophagitis (EoE) is an eosinophil-rich, TH2 antigen-mediated disease of increasing pediatric and adult worldwide prevalence. Diagnosis requires greater than or equal to 15 eosinophils per high-power field on light microscopy. Symptoms reflect esophageal dysfunction, and typical endoscopic features include linear furrows, white plaques, and concentric rings. Progressive disease leads to pathologic tissue remodeling, with ensuing esophageal rigidity and loss of luminal diameter caused by strictures. Therapies include proton pump inhibitors, elimination diets, and topical corticosteroids. Effective treatment can reverse tissue fibrosis in some patients, as well as decrease the rate of food impactions. Esophageal dilation might be required to increase luminal patency. The chronic nature of EoE necessitates long-term therapy to avoid disease recurrence and complications. This review serves the function of providing the current state-of-the-art diagnostic criteria and disease management for adult and pediatric EoE.

Allergies and Eosinophilic Esophagitis-Current Updates for the Pediatric Gastroenterologist

PURPOSE OF REVIEW

The purpose of this article is to review recent developments demonstrating the role of allergies, the utility of allergy testing, and the role of the allergist in eosinophilic esophagitis (EoE) management.

RECENT FINDINGS

The majority of patients with EoE have concurrent atopic disorders including food anaphylaxis, asthma, allergic rhinitis, and eczema. An atopic population likely is at greater risk for EoE. Delayed type hypersensitivity to food antigens is the most common pathogenic mechanism. Aeroallergens and pollen-food cross-reactivity also can trigger EoE. Th2 cell-mediated adaptive and innate immunity in response to epithelial damage occurs via IL-13- and IL-4-producing T cells and innate lymphoid cells. While IgE testing for foods is insufficient to build an elimination diet, IgE-mediated allergy may play a role in EoE severity and clinical course. There is strong evidence that Th2 immunity drives EoE. Optimal EoE management should include elucidating and managing EoE triggers and concurrent atopic diatheses.

Advances in eosinophilic diseases in 2018

Interest in eosinophil biology and eosinophilic diseases is increasing, as reflected in a doubling of the number of annual articles focused on this topic published in the Journal of Allergy and Clinical Immunology over the past decade. Although the majority of these publications relate to eosinophilic asthma, a growing proportion of them focus on breakthroughs in the diagnosis, treatment, and pathogenesis of other eosinophilic disorders, most notably eosinophilic esophagitis. This review highlights advances in our understanding of eosinophilia and eosinophilic disorders (excluding asthma) published in the Journal in 2018.

Prognostic values of lymphocyte and eosinophil counts in resectable cervical squamous cell carcinoma

Aim: Cervical cancer is one of the leading causes of cancer mortality in women. Peripheral white blood cell parameters such as neutrophil (NE), eosinophil (EO), basophil (BA), as well as lymphocyte (LY) and monocyte (MO), are correlated with tumor outcomes. Methods: In total, 110 cervical squamous cell carcinoma patients were recruited in this study. The potential prognostic factors were evaluated by univariate and multivariate survival analysis. Results: Cox regression analysis model indicated that higher pretreatment EO level and increased post-/preradiotherapy EO ratio were independently associated with worse progression-free survival. Lower pretreatment LY or higher EO levels and increased post-/preradiotherapy EO ratio were independently associated with worse overall survival. Conclusion: LY and EO are correlated with outcomes of cervical squamous cell cancer.

Activating mutations in PIK3CD disrupt the differentiation and function of human and murine CD4+ T cells

BACKGROUND

Gain-of-function (GOF) mutations in PIK3CD cause a primary immunodeficiency characterized by recurrent respiratory tract infections, susceptibility to herpesvirus infections, and impaired antibody responses. Previous work revealed defects in CD8⁺ T and B cells that contribute to this clinical phenotype, but less is understood about the role of CD4⁺ T cells in disease pathogenesis.

OBJECTIVE

We sought to dissect the effects of increased phosphoinositide 3-kinase (PI3K) signaling on CD4⁺ T-cell function.

METHODS

We performed detailed ex vivo, in vivo, and in vitro phenotypic and functional analyses of patients' CD4⁺ T cells and a novel murine disease model caused by overactive PI3K signaling.

RESULTS

PI3K overactivation caused substantial increases in numbers of memory and follicular helper T (T_FH) cells and dramatic changes in cytokine production in both patients and mice. Furthermore, PIK3CD GOF human T_FH cells had dysregulated phenotype and function characterized by increased programmed cell death protein 1, CXCR3, and IFN-γ expression, the phenotype of a T_FH cell subset with impaired B-helper function. This was confirmed in vivo in which Pik3cd GOF CD4⁺ T cells also acquired an aberrant T_FH phenotype and provided poor help to support germinal center reactions and humoral immune responses by antigen-specific wild-type B cells. The increase in numbers of both memory and T_FH cells was largely CD4⁺ T-cell extrinsic, whereas changes in cytokine production and T_FH cell function were cell intrinsic.

CONCLUSION

Our studies reveal that CD4⁺ T cells with overactive PI3K have aberrant activation and differentiation, thereby providing mechanistic insight into dysfunctional antibody responses in patients with PIK3CD GOF mutations.

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.

Values of applying white blood cell counts in the prognostic evaluation of resectable colorectal cancer

The count and classification of white blood cells (WBCs) may be used as prognostic markers in certain types of cancer. The present study investigated the prognostic potential of the counts of WBCs, including lymphocytes (LYs), monocytes (MOs), neutrophils (NEs), eosinophils (EOs) and basophils (BAs), in the prognosis of resectable colorectal cancer. The present study recruited 153 resectable colorectal cancer cases retrospectively, which were pathologically confirmed. All patients were divided into two groups, according to the median value of LY (low LY, ≤1.632x109/l or high LY, >1.632x109/l), MO (low MO, ≤0.330x109/l or high MO, >0.330x109/l), NE (low NE, ≤3.600x109/l or high NE, >3.600x109/l), EO (low EO, ≤0.085x109/l or high EO, >0.085x109/l), BA (low BA, ≤0.010x109/l or high BA, >0.010x109/l), or WBC (low WBC, ≤5.780x109/l or high WBC, >5.780x109/l). To evaluate the alterations in WBC counts following surgery and adjuvant chemotherapy; all samples received oxiplatin and capecitabine (XELOX) for 6‑8 cycles or 5‑fluorouracil, leucovorin and oxaliplatin (mFOLFOX6) for 10‑12 cycles. XELOX included oxaliplatin administered intravenously at a dose of 130 mg/m2 on day 1 and 850‑1,250 mg/m2 capecitabine twice daily for days 1‑14, repeated every 3 weeks. mFOLFOX6 included oxaliplatin administered intravenously at a dose of 85 mg/m2, 400 mg/m2 leucovorin and 400 mg/m2 5‑FU on day 1 followed by 1,200 mg/m2/days continuous infusion for 2 days (in total, 2,400 mg/m2 over 46‑48 h), repeated every 2 weeks. The present study investigated the post/pre‑treatment of LY, MO, NE, EO, BA and WBC ratios (≤1 indicated that LY, MO, NE, EO, BA and WBC counts were not increased following therapy; whereas, >1 suggested increased counts). Kaplan‑Meier curves were constructed to demonstrate overall survival (OS). A multivariate and univariate logistic regression analyses model was employed to identify the independent risk factors. Low pre‑treatment BA counts were associated with larger tumor size (>5 cm); pre‑treatment BA levels were positively associated with OS. Surgery significantly decreased the count of BAs and increased the count of EOs; whereas, no effect was observed on LYs, MOs, NEs or WBCs. Adjuvant chemotherapy markedly decreased the counts of LY, NE and WBC; whereas, no notable effects on MOs, EOs or BAs were observed. Whole course treatment (surgery combined with adjuvant chemotherapy) significantly decreased the values of LY, NE and WBC; however, increased the value of EO; no effects on the MO or BA counts were observed. An increased post‑/pre‑treatment NE ratio suggested poorer prognosis. Multivariate Cox regression analysis revealed that sex, tumor size, pre‑treatment BA count and the post‑/pre‑treatment NE ratio were independent prognostic factors affecting OS. The results of the present study suggested that the pre‑treatment BA count and post‑/pre‑treatment NE ratio may be potential prognostic factors for resectable colorectal cancer.

Pathophysiology of eosinophilic esophagitis: recent advances and their clinical implications

Introduction: Diagnostic and therapeutic strategies in eosinophilic esophagitis (EoE) are evolving. New knowledge regarding the pathophysiology of EoE has been the foundation for updated diagnostic recommendations and new therapeutic trials. Areas covered: We performed structured literature searches in Medline and PubMed, Cochrane meta-analyses, and abstracts of international congresses to review therapeutic approaches for EoE in July 2018. Additional articles were obtained by perusing the references of articles identified in the original PubMed search. Articles were excluded if they did not focus on the mechanism of disease, diagnosis, or treatment of humans with EoE. Expert commentary: Recent advances in the understanding of mechanisms underlying the pathology of EoE have resulted in significant change in the diagnostic algorithm for EoE, and are identifying promising potential targets for personalized medicine. There is a clinical need for improved targeted therapy for EoE, and better understanding the underlying pathophysiology of EoE will help to determine therapeutic targets. In this review, we highlight key mechanisms in the pathophysiology of EoE and how they are being utilized to change therapy in EoE.

What Is the Relationship Between Eosinophilic Esophagitis (EoE) and Aeroallergens? Implications for Allergen Immunotherapy

PURPOSE OF REVIEW

Observations suggesting that aeroallergens trigger eosinophilic esophagitis (EoE) in a subset of patients raise questions about the implications this finding has on the evaluation and management of patients with EoE, including a potential role for allergen immunotherapy.

RECENT FINDINGS

The majority of studies evaluating the potential role of aeroallergens as provocateurs of EoE have addressed this issue by assessing the seasonal variation in EoE diagnosis and/or symptom onset or worsening, with mixed results. For various reasons, reaching accurate conclusions based on this methodology is potentially fraught with error. In addition, studies examining the even harder to assess role of perennial aeroallergens in triggering EoE are lacking. Although clearly not the majority, there may be a subset of patients with EoE and allergic rhinitis in whom exposure to aeroallergens to which they are sensitized contributes to esophageal eosinophilia either through direct chronic esophageal mucosal contact with pollen allergens or from repetitive exposure of the esophageal mucosa to pollen allergens, mediators, and eosinophils in swallowed nasal secretions. Therefore, evaluation for and optimal treatment of comorbid allergic rhinitis in EoE patients are clearly indicated. Recognition of the potential role of aeroallergens as triggers of EoE also raises the question of whether allergen immunotherapy might be an effective form of EoE treatment. Reports of sublingual immunotherapy (SLIT) inducing EoE support the notion that aeroallergens can trigger EoE, but negate this approach as a potential form of EoE therapy. In fact, the use of SLIT is contraindicated in patients with EoE. The literature regarding the role of subcutaneous immunotherapy (SCIT) in patients with EoE is limited. Current evidence indicates that it should not be typically recommended; however, SCIT might benefit a subset of patients with EoE and uncontrolled allergic rhinitis on conventional therapies in whom SCIT would otherwise be indicated for allergic rhinoconjunctivitis, particularly in those with sensitizations to pollens containing allergens that cross react with food allergens. The purpose of this review is to discuss the current literature examining the role of aeroallergens in triggering EoE with a focus on the potential clinical implications of this finding on managing patients with EoE.