Immunohistochemical differentiation of eosinophilic esophageal myositis from eosinophilic esophagitis

Expression of inducible nitric oxide synthase, nitrotyrosine, eosinophilic peroxidase, eotaxin-3, and galectin-3 in patients with gastroesophageal reflux disease, eosinophilic esophagitis, and in healthy controls: a semiquantitative image analysis of 3,3'-diaminobenzidine-stained esophageal biopsies

Eosinophilic esophagitis (EoE) and gastroesophageal reflux disease (GERD) share many histopathological features; therefore, markers for differentiation are of diagnostic interest and may add to the understanding of the underlying mechanisms. The nitrergic system is upregulated in GERD and probably also in EoE. Esophageal biopsies of patients with EoE (n = 20), GERD (n = 20), and healthy volunteers (HVs) (n = 15) were exposed to antibodies against inducible nitric oxide synthase (iNOS), nitrotyrosine, eosinophilic peroxidase, eotaxin-3, and galectin-3. The stained object glasses were randomized, digitized, and blindly analyzed regarding the expression of DAB (3,3'-diaminobenzidine) by a protocol developed in QuPath software. A statistically significant overexpression of iNOS was observed in patients with any of the two inflammatory diseases compared with that in HVs. Eotaxin-3 could differentiate HVs versus inflammatory states. Gastroesophageal reflux patients displayed the highest levels of nitrotyrosine. Neither iNOS nor nitrotyrosine alone were able to differentiate between the two diseases. For that purpose, eosinophil peroxidase was a better candidate, as the mean levels increased stepwise from HVs via GERD to EoE. iNOS and nitrotyrosine are significantly overexpressed in patients with EoE and GERD compared with healthy controls, but only eosinophil peroxidase could differentiate the two types of esophagitis. The implications of the finding of the highest levels of nitrotyrosine among gastroesophageal reflux patients are discussed.

Role of mechanoregulation in mast cell-mediated immune inflammation of the smooth muscle in the pathophysiology of esophageal motility disorders

Major esophageal disorders involve obstructive transport of bolus to the stomach, causing symptoms of dysphagia and impaired clearing of the refluxed gastric contents. These may occur due to mechanical constriction of the esophageal lumen or loss of relaxation associated with deglutitive inhibition, as in achalasia-like disorders. Recently, immune inflammation has been identified as an important cause of esophageal strictures and the loss of inhibitory neurotransmission. These disorders are also associated with smooth muscle hypertrophy and hypercontractility, whose cause is unknown. This review investigated immune inflammation in the causation of smooth muscle changes in obstructive esophageal bolus transport. Findings suggest that smooth muscle hypertrophy occurs above the obstruction and is due to mechanical stress on the smooth muscles. The mechanostressed smooth muscles release cytokines and other molecules that may recruit and microlocalize mast cells to smooth muscle bundles, so that their products may have a close bidirectional effect on each other. Acting in a paracrine fashion, the inflammatory cytokines induce genetic and epigenetic changes in the smooth muscles, leading to smooth muscle hypercontractility, hypertrophy, and impaired relaxation. These changes may worsen difficulty in the esophageal transport. Immune processes differ in the first phase of obstructive bolus transport, and the second phase of muscle hypertrophy and hypercontractility. Moreover, changes in the type of mechanical stress may change immune response and effect on smooth muscles. Understanding immune signaling in causes of obstructive bolus transport, type of mechanical stress, and associated smooth muscle changes may help pathophysiology-based prevention and targeted treatment of esophageal motility disorders.NEW & NOTEWORTHY Esophageal disorders such as esophageal stricture or achalasia, and diffuse esophageal spasm are associated with smooth muscle hypertrophy and hypercontractility, above the obstruction, yet the cause of such changes is unknown. This review suggests that smooth muscle obstructive disorders may cause mechanical stress on smooth muscle, which then secretes chemicals that recruit, microlocalize, and activate mast cells to initiate immune inflammation, producing functional and structural changes in smooth muscles. Understanding the immune signaling in these changes may help pathophysiology-based prevention and targeted treatment of esophageal motility disorders.

Characterization of SHARPIN knockout Syrian hamsters developed using CRISPR/Cas9 system

BACKGROUND

SHARPIN (SHANK-associated RH domain interactor) is a component of the linear ubiquitination complex that regulates the NF-κB signaling pathway. To better understand the function of SHARPIN, we sought to establish a novel genetically engineered Syrian hamster with SHARPIN disruption using the CRISPR/Cas9 system.

METHODS

A single-guide ribonucleic acid targeting exon 1 of SHARPIN gene was designed and constructed. The zygotes generated by cytoplasmic injection of the Cas9/gRNA ribonucleoprotein were transferred into pseudopregnant hamsters. Neonatal mutants were identified by genotyping. SHARPIN protein expression was detected using Western blotting assay. Splenic, mesenteric lymph nodes (MLNs), and thymic weights were measured, and organ coefficients were calculated. Histopathological examination of the spleen, liver, lung, small intestine, and esophagus was performed independently by a pathologist. The expression of lymphocytic markers and cytokines was evaluated using reverse transcriptase-quantitative polymerase chain reaction.

RESULTS

All the offspring harbored germline-transmitted SHARPIN mutations. Compared with wild-type hamsters, SHARPIN protein was undetectable in SHARPIN-/- hamsters. Spleen enlargement and splenic coefficient elevation were spotted in SHARPIN-/- hamsters, with the descent of MLNs and thymuses. Further, eosinophil infiltration and structural alteration in spleens, livers, lungs, small intestines, and esophagi were obvious after the deletion of SHARPIN. Notably, the expression of CD94 and CD22 was downregulated in the spleens of knockout (KO) animals. Nonetheless, the expression of CCR3, CCL11, Il4, and Il13 was upregulated in the esophagi. The expression of NF-κB and phosphorylation of NF-κB and IκB protein significantly diminished in SHARPIN-/- animals.

CONCLUSIONS

A novel SHARPIN KO hamster was successfully established using the CRISPR/Cas9 system. Abnormal development of secondary lymphoid organs and eosinophil infiltration in multiple organs reveal its potential in delineating SHARPIN function and chronic inflammation.

Novel Method of Sampling the Gastrointestinal Muscle Layer: Feasibility of Endoscopic Muscular Resection with a Ligation Device in an in Vivo Porcine Model

BACKGROUND

Gastrointestinal muscular sampling is useful in the histological assessment of functional gastrointestinal disorders. We devised a new sampling method to obtain a large volume of muscle tissues and then investigated the feasibility and safety of endoscopic muscular resection with a ligation device in an in vivo porcine model.

METHODS

After establishing a submucosal tunnel, a rubber band was placed on the muscle tissue by sucking the exposed muscle layer. Thereafter, the established pseudopolyp was removed using an electrocautery snare, and the entry site of the submucosal tunnel was closed endoscopically. This procedure was performed at three sites in the esophagus and stomach of two pigs. The technical success, histology, and survival rate on postoperative day 7 were examined postoperatively.

RESULTS

We successfully completed the mentioned procedure in 11 of the 12 sites (92%), without the occurrence of severe adverse events. The median diameters of obtained tissues from the esophagus and stomach, respectively, were 5 mm and 10 mm. Histologically, both the inner and outer muscle layers were included in all specimens. The postprocedural course was found uneventful in both pigs during the observatory period.

CONCLUSIONS

Endoscopic muscular resection using a ligation device enabled us to obtain large and thick muscle tissue samples. This approach may facilitate more precise histological assessments of functional gastrointestinal disorders.

Jackhammer Esophagus: Current Concepts and Dilemmas

Jackhammer esophagus (JE) is a recently recognized esophageal motility disorder that is characterized by hypercontractile peristalsis. More than 500 cases have been reported in the literature. Among patients referred for esophageal motility disorders, the prevalence of JE ranges from 0.42% to 9%, with most series describing a prevalence of 2% to 4%. Most cases are women (60.5%). The mean reported age of patients with JE is 65.2 years, and patients commonly have dysphagia (62.8%). Reflux symptoms occur in ∼40% of patients, and chest pain affects more than one-third of patients (36.4%). JE is a heterogenous disorder that is associated with several conditions, including obesity, opioid use, lung transplantation, eosinophilic infiltration of the esophagus, neoplasia, and systemic diseases. The cause and pathogenesis remain unknown, but several observations suggest that it is the result of multiple conditions that likely precipitate increased excitation and abnormal inhibition of neuromuscular function. The natural course of JE also is unknown, but progression to achalasia has been observed in a few patients. Treatment is challenging, in part because of the insufficient understanding of the disorder's underlying mechanisms. Various therapeutic modalities have been used, ranging from observation only to pharmacologic and endoscopic interventions (eg, botulinum toxin injection) to peroral endoscopic myotomy. Treatment efficacy remains largely anecdotal and insufficiently studied.

Differences in clinical characteristics between conservative-treatment-response group and refractory (surgical-treatment) group in patients with jackhammer esophagus

BACKGROUND

Jackhammer esophagus (JE) is a rare disease with unclear clinical features. The objective of this study was to retrospectively compare the clinical characteristics of patients with JE whose symptoms were controlled with conservative treatment, such as observation or medication, versus those who were required surgical treatment, such as surgical myotomy or per oral endoscopic myotomy.

METHODS

Eighteen patients with JE were included in this study. The patients were divided into two groups: patients who responded to conservative treatment (C group) and patients who were refractory to conservative treatment and underwent surgery (S group). Patient age, sex, disease duration before treatment, symptoms, esophagogastroduodenoscopic (EGD) findings, esophagographic findings, esophageal wall thickness on computed tomography, number of swallows with hypercontractile peristalsis in 10 water swallows, and maximum distal contractile integral (DCI) were compared between the groups.

RESULTS

Thirteen of 18 patients (72%) were in the C group and five of 18 (28%) were in the S group. There were no significant differences in age, sex, disease duration before treatment, symptoms, EGD findings, esophagographic findings, esophageal wall thickness, or number of swallows with hypercontractile peristalsis between the groups. On Starlet high-resolution manometry, the median maximum DCI value was significantly higher in the S group (32,651 mmHg-s-cm) than in the C group (17,926 mmHg-s-cm) (P = 0.0136).

CONCLUSIONS

JE treatment should be carefully considered because some patients require surgery, whereas others are controlled with conservative treatment alone. A higher DCI value in patients with JE may predict resistance to conservative treatment.

Immunohistochemical markers for eosinophilic esophagitis

BACKGROUND AND AIMS

Eosinophilic esophagitis (EoE) is a chronic, local immune-mediated esophageal disease with eosinophil-dominated inflammation. The incidence of the disease is rapidly increasing in both children and adults. The pathogenesis of the disease is still not well understood. We present a review of the literature devoted to the EoE immunopathology, in particular the markers of inflammation and epithelial integrity, and their usefulness in disease monitoring and therapy.

METHODS

We performed a systematic search of the MEDLINE/PubMed databases for studies to examine the use of immunohistochemistry as a diagnostic tool for EoE.

RESULTS

The gold standard of EoE diagnosis requires multiple endoscopies with biopsies for histological assessment. The minimum number of eosinophils evaluated in hematoxylin-eosin staining to diagnose EoE is 15 per high-power field in at least one esophageal mucosa biopsy. However, in some cases, the count of eosinophils is not specific and insufficient as the only indicator. Recent works confirm the usefulness of assessment of some biomarkers in establishing the diagnosis and monitoring the treatment effects.

CONCLUSIONS

Immunohistochemistry seems to be a promising option not only in clinical recognition, but also in the selection and monitoring of treatment effects. However, these methods have not yet recommended for routine clinical use.

Symptom-based diagnostic approach for eosinophilic esophagitis

The prevalence of eosinophilic esophagitis (EoE) has been increasing in Japan. Although the diagnosis of EoE is based on simple criteria that include the presence of esophageal symptoms and esophageal eosinophilia on biopsies, there are several important issues associated with the diagnostic approach. Following an extensive literature search, the symptoms of 886 EoE cases in Japanese adults were analyzed and divided into three categories as follows: (1) typical symptoms, such as dysphagia (53%); (2) other upper GI symptoms (40%); and (3) no symptoms found during screening or medical examination, i.e., "asymptomatic esophageal eosinophilia" (19%). The diagnostic approach was reviewed according to these categories as well as according to the presence or absence of esophageal eosinophilia. The present manuscript describes the current therapeutic strategy of EoE and ultimately proposes a symptom-based diagnostic approach for EoE.

Identification of human herpes virus 1 encoded microRNAs in biopsy samples of lower esophageal sphincter muscle during peroral endoscopic myotomy for esophageal achalasia

Esophageal achalasia is a rare chronic debilitating disorder characterized by incomplete lower esophageal sphincter (LES) relaxation and abnormal peristalsis as a result of myenteric plexus degeneration. Although complex interactions among immunity, viruses and inheritance have been proposed, its causes remain unknown. MicroRNAs (miRs) play crucial roles in the regulation of gene expression during pathophysiological processes. Certain viruses such as herpes simplex virus (HSV) encode miRs derived from their own genomes. To determine the underlying relationship of miRNAs to achalasia, we analyzed the expression profile of miRNAs using biopsy samples obtained from LES muscle during peroral endoscopic myotomy. Peroral LES muscle biopsy sampling was uneventfully carried out in our case series of achalasia. Control biopsy tissues were also obtained from LES muscle of patients without symptoms relating to abnormal esophageal motility whose esophagogastric junction was surgically excised. RNA was extracted from biopsy specimens and analyzed using a microarray. Differentially expressed miRNAs in achalasia patients compared to controls were identified and analyzed using reverse transcription quantitative polymerase chain reaction. HSV-1-derived hsv1-miR-H1 and -H18 was significantly overexpressed in achalasia cohorts compared to controls. Correlations between the expression levels of viral miR and the patients' clinical characteristics including achalasia morphological type, dilatation grading, and disease duration were not identified. Further studies with a larger sample size are needed to replicate the current heuristic identification of neurotropic viral miRs and unravel their functional significance in order to provide new insight linking neurodegenerative etiology in achalasia.

Recent advances in dysphagia management

The literal definition of dysphagia is "disturbed eating". However, it is more accurately described in clinical practice as a sensation of food or liquid being stuck in the esophagus or chest. If this sensation is associated with pain, it is labeled odynophagia, and if it is associated with persistent obstruction and bolus retention, it is categorized as a food impaction. Through research and technological advances, we continue to expand our understanding of the etiologies and underlying pathophysiology relating to this complaint. However, for now, our clinical algorithms focus on endoscopy and manometry to break down dysphagia into three categories: obstructive dysphagia, esophageal motility disorders, and functional dysphagia. Here, we review some critical pitfalls in our current clinical diagnoses, new proposed underlying mechanisms of esophageal motor disorders, and developing technologies to aid in diagnosis and treatment.

Esophageal motility disorders: new perspectives from high-resolution manometry and histopathology

High-resolution manometry (HRM) and peroral endoscopic myotomy (POEM) have contributed significantly to the field of esophageal motility disorders in recent years. The development of HRM has categorized various esophageal motility disorders with a focus on a diverse range of manometric anomalies. Additionally, the Chicago classification criteria is widely used for manometric diagnosis. Moreover, POEM was introduced as a minimally invasive radical therapy for achalasia and shows promise for other spastic esophageal motility disorders as well. POEM has also enabled a transluminal endoscopic approach for determining the histology of the esophageal muscle layer, which is expected to assist in elucidating the etiology of disorders associated with esophageal motility. The purpose of this review is to update the diagnosis, pathology, and treatment of esophageal motility disorders, with a focus on the recent advances in this field.

Proposed criteria to differentiate heterogeneous eosinophilic gastrointestinal disorders of the esophagus, including eosinophilic esophageal myositis

AIM

To define clinical criteria to differentiate eosinophilic gastrointestinal disorder (EoGD) in the esophagus.

METHODS

Our criteria were defined based on the analyses of the clinical presentation of eosinophilic esophagitis (EoE), subepithelial eosinophilic esophagitis (sEoE) and eosinophilic esophageal myositis (EoEM), identified by endoscopy, manometry and serum immunoglobulin E levels (s-IgE), in combination with histological and polymerase chain reaction analyses on esophageal tissue samples.

RESULTS

In five patients with EoE, endoscopy revealed longitudinal furrows and white plaques in all, and fixed rings in two. In one patient with sEoE and four with EoEM, endoscopy showed luminal compression only. Using manometry, failed peristalsis was observed in patients with EoE and sEoE with some variation, while EoEM was associated with hypercontractile or hypertensive peristalsis, with elevated s-IgE. Histology revealed the following eosinophils per high-power field values. EoE = 41.4 ± 7.9 in the epithelium and 2.3 ± 1.5 in the subepithelium; sEoE = 3 in the epithelium and 35 in the subepithelium (conventional biopsy); EoEM = none in the epithelium, 10.7 ± 11.7 in the subepithelium (conventional biopsy or endoscopic mucosal resection) and 46.8 ± 16.5 in the muscularis propria (peroral esophageal muscle biopsy). Presence of dilated epithelial intercellular space and downward papillae elongation were specific to EoE. Eotaxin-3, IL-5 and IL-13 were overexpressed in EoE.

CONCLUSION

Based on clinical and histological data, we identified criteria, which differentiated between EoE, sEoE and EoEM, and reflected a different pathogenesis between these esophageal EoGDs.