Activated Eosinophils are Present in Esophageal Muscle in Patients with Achalasia of the Esophagus

Achalasia alters physiological networks depending on sex

Achalasia is a rare esophageal motility disorder for which the etiology is not fully understood. Evidence suggests that autoimmune inflammatory infiltrates, possibly triggered by a viral infection, may lead to a degeneration of neurons within the myenteric plexus. While the infection is eventually resolved, genetically susceptible individuals may still be at risk of developing achalasia. This study aimed to determine whether immunological and physiological networks differ between male and female patients with achalasia. This cross-sectional study included 189 preoperative achalasia patients and 500 healthy blood donor volunteers. Demographic, clinical, laboratory, immunological, and tissue biomarkers were collected. Male and female participants were evaluated separately to determine the role of sex. Correlation matrices were constructed using bivariate relationships to generate complex inferential networks. These matrices were filtered based on their statistical significance to identify the most relevant relationships between variables. Network topology and node centrality were calculated using tools available in the R programming language. Previous occurrences of chickenpox, measles, and mumps infections have been proposed as potential risk factors for achalasia, with a stronger association observed in females. Principal component analysis (PCA) identified IL-22, Th2, and regulatory B lymphocytes as key variables contributing to the disease. The physiological network topology has the potential to inform whether a localized injury or illness is likely to produce systemic consequences and the resulting clinical presentation. Here we show that immunological involvement in achalasia appears localized in men because of their highly modular physiological network. In contrast, in women the disease becomes systemic because of their robust network with a larger number of inter-cluster linkages.

A single-cell transcriptional landscape of immune cells shows disease-specific changes of T cell and macrophage populations in human achalasia

Achalasia is a rare motility disorder of the esophagus caused by the gradual degeneration of myenteric neurons. Immune-mediated ganglionitis has been proposed to underlie the loss of myenteric neurons. Here, we measure the immune cell transcriptional profile of paired lower esophageal sphincter (LES) tissue and blood samples in achalasia and controls using single-cell RNA sequencing (scRNA-seq). In achalasia, we identify a pattern of expanded immune cells and a specific transcriptional phenotype, especially in LES tissue. We show C1QC+ macrophages and tissue-resident memory T cells (TRM), especially ZNF683+ CD8+ TRM and XCL1+ CD4+ TRM, are significantly expanded and localized surrounding the myenteric plexus in the LES tissue of achalasia. C1QC+ macrophages are transcriptionally similar to microglia of the central nervous system and have a neurodegenerative dysfunctional phenotype in achalasia. TRM also expresses transcripts of dysregulated immune responses in achalasia. Moreover, inflammation increases with disease progression since immune cells are more activated in type I compared with type II achalasia. Thus, we profile the immune cell transcriptional landscape and identify C1QC+ macrophages and TRM as disease-associated immune cell subsets in achalasia.

The molecular pathogenesis of achalasia: a paired lower esophageal sphincter muscle and serum 4D label-free proteomic study

Background

Achalasia is a primary esophageal motility disorder with potential molecular pathogenesis remaining uncertain. This study aimed to identify the differentially expressed proteins and potential pathways among achalasia subtypes and controls to further reveal the molecular pathogenesis of achalasia.

Methods

Paired lower esophageal sphincter (LES) muscle and serum samples from 24 achalasia patients were collected. We also collected 10 normal serum samples from healthy controls and 10 normal LES muscle samples from esophageal cancer patients. The 4D label-free proteomic analysis was performed to identify the potential proteins and pathways involved in achalasia.

Results

Analysis of Similarities showed distinct proteomic patterns of serum and muscle samples between achalasia patients and controls (both P < 0.05). Functional enrichment analysis suggested that these differentially expressed proteins were immunity-, infection-, inflammation-, and neurodegeneration-associated. The mfuzz analysis in LES specimens showed that proteins involved in the extracellular matrix-receptor interaction increased sequentially between the control group, type III, type II, and type I achalasia. Only 26 proteins altered in the same directions in serum and muscle samples.

Conclusions

This first 4D label-free proteomic study of achalasia indicated that there were specific protein alterations in both the serum and muscle of achalasia, involving immunity, inflammation, infection, and neurodegeneration pathways. Distinct protein clusters between types I, II, and III revealed the potential molecular pathways associated with different disease stages. Analysis of proteins changed in both muscle and serum samples highlighted the importance of further studies on LES muscle and revealed potential autoantibodies.

Eosinophils Infiltration in Esophageal Muscularis Propria Induces Achalasia-like Esophageal Motility Disorder in Mice

Eosinophil infiltration in esophageal muscularis propria is common in achalasia (AC). This study aims to evaluate the effect of eosinophil infiltration in muscularis propria of the esophagus on esophageal motility in mice. A mouse model with eosinophil infiltration in the esophageal muscle layer was established by long term Ovalbumin (OVA) exposure. The histopathology features of esophageal muscularis propria as well as parameters of esophageal motility, such as lower esophageal sphincter pressure (LESP) and esophageal emptying, were compared between model and control group. In addition, the histopathology and motility of esophagus at each time point in the model group were compared. The esophageal motor function severely deteriorated in the model group, mimicking the abnormal esophageal motility of AC, with more eosinophils and fewer SOX-10-IR cells in esophageal muscularis propria in the model group, compared with control. With the prolongation of OVA treatment, esophageal motility disorder was aggravated, accompanied by increased eosinophils in the the muscle layer of esophagus and decreased SOX-10-IR cells in the model group. In addition, the eosinophil count was negatively correlated with SOX-10-IR cells. Long-term exposure to OVA assisted by alum may induce eosinophil infiltration in esophageal muscularis propria, reduced SOX-10-IR cells and abnormal esophageal motility, which simulates the functional and histopathological features of some AC patients. This suggests that eosinophil infiltration in esophageal muscularis propria may play a role in the pathogenesis of a subgroup of AC.

"M1/M2" Muscularis Macrophages Are Associated with Reduction of Interstitial Cells of Cajal and Glial Cells in Achalasia

BACKGROUND AND AIMS

Several studies showed muscularis macrophages (MMφ) are associated with GI motility disorders. The purpose of this study was to preliminary explore the association between MMφ and achalasia.

METHODS

Tissue samples of the lower esophageal sphincter (LES) high-pressure zone were obtained from 27 achalasia patients and 10 controls. Immunohistochemistry for MMφ, interstitial cells of Cajal (ICC), neuronal nitric oxide synthase (nNOS), and glial cells were conducted. Histological characteristics were compared between groups, and correlation analysis was performed.

RESULTS

Fewer ICC was found in achalasia compared with controls (P = 0.018), and the level of M1 macrophages was higher than that in controls no matter in terms of the number or the proportion of M1(P = 0.026 for M1 and 0.037 for M1/MMφ). Statistical differences were found between two groups in terms of proportion of M2 and ratio of M1 to M2 (P = 0.048 for M2/ MMφ and < 0.001 for M1/M2). For the correlation analysis, significant correlations were detected between levels of nNOS, ICC, and glial cells in patients with achalasia (P = 0.026 for nNOS and ICC, 0.001 for nNOS and glial cells, 0.019 for ICC and glial cells). There were significant correlations between M2/MMφ and levels of ICC (P = 0.019), glial cells (P = 0.004), and nNOS (P = 0.135).

CONCLUSION

Patients with achalasia had a higher level of M1/M2 ratio in LES and significant correlations were found between M2/MMφ and numbers of ICC and glial cells, which suggested that MMφ were probably associated with occurrence and development of achalasia.

Effect of esophageal muscle fibrosis on prognosis of per-oral endoscopic myotomy (POEM) in achalasia patients

BACKGROUND AND AIMS

Although esophageal smooth muscle fibrosis of achalasia (AC) patients has been described, the role and mechanism remain unclear. The aim of this study was to evaluate the fibrosis in the distal esophageal muscle in patients with AC and explore its relationship with prognosis of per-oral endoscopic myotomy (POEM).

METHODS

Lower esophageal sphincter (LES) muscle from forty patients undergoing POEM for AC were obtained at the time of surgery. Control specimens consisted of similar muscle taken from distal esophagectomy for gastric tumors. The muscle fibrosis were assessed by Masson staining and confirmed by immunohistochemistry for collagen I and III. The total number of eosinophil within the myenteric propria were counted. In addition, clinical data were obtained through electronic medical records. Statistical comparison between groups were made.

RESULTS

A significantly higher proportion of fibrosis in AC as compared with controls (P = 0.000). Eosinophil count, TGF-β1, collagen I, and III were higher than those of control (P = 0.000, P = 0.001, P = 0.011, and P = 0.002, respectively). TGF-β1, collagen I, and III were positively correlated with eosinophil count (all P < 0.05). Furthermore, the proportion of severe LES fibrosis in patients who failed to respond to POEM two years after operation was higher than that in responders (P = 0.028). And, Eckardt score two years after POEM was also positively correlated with degree of fibrosis-related cytokines (all P < 0.05).

CONCLUSION

Smooth muscle fibrosis was prominent in lower part of esophagus of AC and positively correlated with severity of symptoms two years after POEM. The fibrosis might be relevant to eosinophil infiltration and TGF-β1. Further studies are required to more clearly delineate the mechanism of muscle fibrosis and its correlation with prognosis of therapy for this idiopathic disease.

Achalasia

Achalasia is a rare disorder of the oesophageal smooth muscle characterized by impaired relaxation of the lower oesophageal sphincter (LES) and absent or spastic contractions in the oesophageal body. The key pathophysiological mechanism is loss of inhibitory nerve function that probably results from an autoimmune attack targeting oesophageal myenteric nerves through cell-mediated and, possibly, antibody-mediated mechanisms. Achalasia incidence and prevalence increase with age, but the disorder can affect all ages and both sexes. Cardinal symptoms consist of dysphagia, regurgitation, chest pain and weight loss. Several years can pass between symptom onset and an achalasia diagnosis. Evaluation starts with endoscopy to rule out structural causes, followed by high-resolution manometry and/or barium radiography. Functional lumen imaging probe can provide complementary evidence. Achalasia subtypes have management and prognostic implications. Although symptom questionnaires are not useful for diagnosis, the Eckardt score is a simple symptom scoring scale that helps to quantify symptom response to therapy. Oral pharmacotherapy is not particularly effective. Botulinum toxin injection into the LES can temporize symptoms and function as a bridge to definitive therapy. Pneumatic dilation, per-oral endoscopic myotomy and laparoscopic Heller myotomy can provide durable symptom benefit. End-stage achalasia with a dilated, non-functioning oesophagus may require oesophagectomy or enteral feeding into the stomach. Long-term complications can, rarely, include oesophageal cancer, but surveillance recommendations have not been established.

Simultaneous Examination of Eosinophil Infiltration in Esophageal Mucosa and Muscle in Patients with Achalasia: Direct Biopsy of the Esophageal Muscle at Per-oral Endoscopic Myotomy

BACKGROUND

The relationship between eosinophilic esophagitis (EoE) and achalasia is not completely understood. There have been reports of eosinophilic infiltration of all esophageal layers in patients with achalasia. However, a routine endoscopic biopsy of the muscular layer is usually not feasible. We evaluate the safety and efficacy of muscle layer biopsy during per-oral endoscopic myotomy (POEM) as well as the prevalence of eosinophilic infiltration of the esophageal mucosa and muscular layer in patients with achalasia.

PATIENTS AND METHODS

All enrolled patients had diagnosed achalasia and had simultaneous biopsies of the muscular layer at the middle esophagus and distal esophageal sphincter as well as the mucosal layer of the proximal and distal esophagus during POEM. All POEM procedures took place from August 2018 to December 2018 or September 2019 to November 2019. Various demographic, disease-related, and procedure-related data were collected from chart review. Eosinophilic infiltration in the biopsy specimen was examined.

KEY RESULTS

Twenty consecutive patients (65% female, age range: 21-84) with a pre-procedure Eckardt score of >6 were enrolled during the study period, with the duration of their achalasia ranging from 1 to 32 years. Eighteen patients had clinical symptomatic improvement after POEM, as defined by an Eckardt score <3. Endoscopic examination did not reveal any signs of eosinophilic esophagitis. Pathologic examination of biopsies revealed eosinophilic infiltration in three of 20 patients (15%) in the distal esophageal mucosa (all <15 eosinophils/HPF) and none in the proximal esophageal mucosa. There was no eosinophilic infiltration in the distal esophageal sphincter and the middle esophageal muscle. No complication was noted due to muscle biopsy.

CONCLUSIONS AND INFERENCES

Submucosal tunneling during POEM provides a safe access for direct esophageal muscle biopsy. This is the first report of the simultaneous biopsy of the esophageal mucosa and muscle in patients with achalasia. Contrary to all previously published studies, the association of esophageal eosinophilic infiltration and achalasia was not observed in this small sample study. Based on our findings, immune or autoimmune reaction rather than direct eosinophilic infiltration in the muscle is more likely the cause of achalasia.

Dysmotility in Eosinophilic Esophagitis

Eosinophilic esophagitis (EoE) is an immune mediated chronic inflammatory disease resulting from antigen exposure and is characterized by mucosal inflammation with eosinophils. Diagnosis is based on the histological finding of at least 15 eosinophils per high power field in esophageal biopsy specimens from upper gastrointestinal endoscopies. These endoscopies are usually performed in the setting of esophageal dysfunction, however, EoE can occasionally be incidentally diagnosed during endoscopies performed for other indications like coeliac disease. The eosinophilia is in the absence of other causes of esophageal eosinophilia (e.g., parasitic infection, esophageal leiomyomatosis or Crohn's disease). Presentation can be wide ranging and often varies according to age. Infants and younger children can present with choking/gagging, feed refusal, failure to thrive, irritability and vomiting. Older children and adults commonly present with dysphagia, chest pain or food bolus obstruction. EoE was first described in the 1970s, but was only recognized as a distinct disease entity in the 1990s. It has been rising in incidence and prevalence, with reported prevalence ranging between 1 in 2,500 and 1 in 10,000. Although the diagnosis of EoE is dependent on clear histopathologic diagnostic criteria, there is a disconnect between the degree of esophageal eosinophilia and symptom severity especially that of reported dysphagia. Multiple anatomical changes can be seen in the spectrum of presentations of EoE which explain dysphagia, including isolated strictures, diffuse trachealisation, fixed rings, including Schatzki, as well as tissue remodeling and fibrotic changes. However, a majority of EoE patients do not have any of these findings and will still often report ongoing dysphagia. Some will report ongoing dysphagia despite histological remission. This suggests an underlying esophageal dysmotilty which cannot be assessed with endoscopy or correlated with histological changes seen in biopsies. This review will describe the types of motor disturbances seen and their prevalence, the pathophysiological basis of dysmotility seen in EoE, how best to investigate esophageal dysfunction in EoE and the role of manometry in the management of EoE.

Histologic Findings in Mucosa and Muscularis Propria Biopsied During Peroral Endoscopic Myotomy in Patients With Achalasia

Background

Peroral endoscopic myotomy (POEM) has been increasingly used to treat achalasia. Previous studies have reported high frequency of muscular eosinophilic infiltration in achalasia. Esophageal mucosal changes in achalasia have only been studied in esophagectomy specimens. Cardia mucosal changes in achalasia have not been reported previously. We aimed to further characterize the esophageal, gastric cardia, and muscularis propria changes in achalasia.

Methods

This was a pilot study. Patients with clinically and radiographically confirmed achalasia who underwent POEM were enrolled in the study. Mucosal biopsies were taken 1 cm proximal and 1 cm distal to the gastroesophageal junction, and muscularis propria biopsies were taken from the mid esophagus. Tissues were submitted for histological evaluation.

Results

Eighteen patients (10 male and eight female, mean age: 60.7 (standard deviation (SD): 13) years) were enrolled in this pilot study. Nine patients had type II achalasia, two type III, one type I, five esophageal gastric outlet obstruction, and one unspecific type achalasia. The mean duration of symptoms prior to POEM was 79 (range 1 - 480) months. All patients had a dilated esophagus on examination, but no endoscopic evidence of Barrett's esophagus. Esophageal, gastric cardia, and muscular biopsies were performed in 17, 13, and 17 patients, respectively. Basal hyperplasia, spongiosis, ballooning, and parakeratosis were seen in 92.3%, 100%, 100%, and 76.5% of cases, respectively. Intraepithelial lymphocytosis was seen in 70.5% of cases, and active esophagitis was seen in 23.5% of case. Six (35.3%) cases had few intraepithelial eosinophils, but none of them had > 15 eosinophils per high power field. Histologic findings in gastric cardia mucosa included carditis (69.2%), H. pylori gastritis (7.6%), and reactive gastropathy (15.4%). One case (7.6%) showed low-grade dysplasia arising from intestinal metaplasia in the cardia. Absence of ganglion cells in the muscular biopsies was noted in 88.2% of cases, and the remaining two showed rare residual ganglion cells with ganglionitis in one case (5.8%). Muscular atrophy and interstitial fibrosis were observed in 52.9% and 82.3% of the cases, respectively. Two cases (11.7%) had eosinophilic inflammation in the muscularis propria and one of them was accompanied by lymphocytic inflammation.

Conclusions

Muscular biopsies in our study revealed loss of ganglion cells, supporting the view that achalasia is a primary esophageal disease with ganglion cell depletion. Squamous mucosa in achalasia showed changes mimicking reflux and lymphocytic esophagitis. Cardia mucosa in achalasia patients often were inflamed and uncommonly showed intestinal metaplasia and glandular dysplasia.

Diagnosis and Management of Achalasia: Updates of the Last Two Years

Achalasia is a rare neurodegenerative disorder causing dysphagia and is characterized by abnormal esophageal motor function as well as the loss of lower esophageal sphincter (LES) relaxation. The assessment and management of achalasia has significantly progressed in recent years due to the advances in high-resolution manometry (HRM) technology along with the improvements and innovations of therapeutic endoscopy procedures. The recent evolution of HRM technology with the inclusion of an adjunctive test, fluoroscopy, and EndoFLIP has enabled more precise diagnoses of achalasia to be made and the subgrouping into therapeutically meaningful subtypes. Current management possibilities include endoscopic treatments such as Botulinum toxin injected to the LES and pneumatic balloon dilation. Surgical treatment includes laparoscopic Heller myotomy and esophagectomy. Furthermore, in recent years, per oral endoscopic myotomy (POEM) has established itself as a principal endoscopic therapeutic alternative to the traditional laparoscopic Heller myotomy. The latest randomized trials report that POEM, pneumatic balloon dilatation, and laparoscopic Heller's myotomy have comparable effectiveness and complications rates. The aim of the current review is to provide a practical clinical approach to dysphagia and to shed light on the most recent improvements in diagnostics and treatment of achalasia over the last two years.

Achalasia and Obstructive Motor Disorders Are Not Uncommon in Patients With Eosinophilic Esophagitis

BACKGROUND

An association has been reported between achalasia and eosinophilic esophagitis (EoE). We performed a retrospective study of high-resolution manometry (HRM) patterns in a large cohort of patients with EoE.

MATERIAL AND METHODS

We collected data from consecutive patients with a new diagnosis of EoE from 2012 through 2019 undergoing HRM during the initial assessment at different centers in Italy. Demographic, clinical, endoscopic and histological characteristics were recorded at baseline and during management. Diagnoses of EoE and esophageal motility disorders were made according to established criteria. Treatments offered included proton pump inhibitors and topical steroids for EoE, and pneumatic dilation and myotomy for achalasia. Response to therapy was defined as less than 15 eosinophils per high power field in esophageal biopsies.

RESULTS

Of 109 consecutive patients (mean age 37 years, 82 male), 68 (62%) had normal findings from HRM. Among 41 patients with motor disorders, 24 (59%) had minor motor disorders and 17 (41%) presented with major motor disorders, including 8 with achalasia (1 with type 1, 4 with type 2, and 3 with type 3). Achalasia and nonachalasia obstructive motor disorders had 14.7% prevalence among patients with EoE. Achalasia was more frequent in women, with longer diagnostic delay and abnormal esophagogram (P < .05) compared with EoE without achalasia or obstructive motor disorders. Clinical features and endoscopic findings did not differ significantly between patients with EoE with vs without achalasia and obstructive motor disorders. A higher proportion of patients without achalasia and obstructive motor disorders responded to topical steroids than patients with these features (P < .005). Invasive achalasia management was required for symptom relief in 50% of patients with achalasia and obstructive motor disorders.

CONCLUSION

Achalasia and obstructive motor disorders are found in almost 15% of patients with EoE, and esophageal eosinophilia might cause these disorders. Patients with EoE who do not respond to standard treatments might require targeted muscle disruption.

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.

The etiology of achalasia: An immune-dominant disease

There is accumulating evidence suggesting that an autoimmune component is involved in esophageal achalasia. An increase in immune cells, cytokines, chemokines, and autoimmune antibodies in serum and infiltration of immune cells in tissues support the view that immune-mediated inflammation is a crucial pathogenesis of inhibitory neuron degeneration in the lower esophageal sphincter. Infection of viruses such as the herpes virus family has been suspected of provoking the autoimmune reaction. Meanwhile, previous reports on immunogenetics have proposed that specific risk alleles on the human leukocyte antigen complex define the susceptible population to achalasia. In this study we reviewed current knowledge regarding the immune-related factors of achalasia, including immunology, viral infection and immunogenetic variations.

Eosinophilic Esophagitis and Achalasia: Two Distinct Nosologic Entities or a Possible Etiopathogenic Association?

BACKGROUND

Despite the fact that researchers have made significant progress in elucidating the pathophysiology of esophageal diseases, the understanding of esophageal motility alterations in patients with eosinophilic esophagitis (EoE) is in its infancy and current published medical literature remains rather scarce on this topic. A growing body of scientific data regarding associations between esophageal motor disorders, such as achalasia and EoE, exists nowadays.

SUMMARY

It seems that the association of EoE and achalasia does not constitute a cause and effect relationship, as it is not clear whether esophageal motility abnormalities are the result of EoE or vice versa. As such, there is no universally accepted treatment algorithm for patients presenting with both of these entities. Key Messages: The aim of this article is to review the existing data on achalasia-like motility disorders in patients with EoE, highlighting a possible association between these 2 esophageal disorders. Moreover, we seek to describe the clinical presentation in such cases, diagnostic modalities to be used, and current treatment strategies in patients suspected to suffer from both disorders.

Oesophageal eosinophilia and oesophageal diseases in children: are the limits clear?

Gastro-oesophageal reflux disease, eosinophilic oesophagitis and oesophageal motility disorders are among the most common diseases accompanying oesophageal eosinophilia. They have similarities and their limits are frequently not well defined. This article reviews the main characteristics relating to their similarities and differences, highlighting existing controversies among these diseases, in addition to current knowledge. In the case of a patient with symptoms of oesophageal dysfunction, it is suggested to carry out an integral analysis of the clinical features and diagnostic test results, including histology, while individualising each case before confirming a definitive diagnosis. Future investigation in paediatric patients is necessary to assess eosinophilic infiltration in the various layers of the oesophageal tissue, along with its clinical and pathophysiological implications.

Eosinophilic esophagitis: novel concepts regarding pathogenesis and clinical manifestations

This report explores two hypotheses regarding eosinophilic esophagitis (EoE): (1) that the use of proton pump inhibitors (PPIs) might contribute to the pathogenesis of EoE by preventing peptic digestion of food allergens, by increasing gastric mucosal permeability to enable gastric absorption of those undegraded food allergens, and by causing microbial dysbiosis, and (2) that EoE, like eosinophilic gastroenteritis, might have mucosal-predominant and muscle-predominant forms, and that the muscle-predominant form of EoE might cause a variety of esophageal motility disorders including achalasia.

Can Eosinophilic Esophagitis Cause Achalasia and Other Esophageal Motility Disorders?

Eosinophilic esophagitis (EoE), a disorder identified by its esophageal mucosal features, often is associated with esophageal motility abnormalities, which are manifestations of esophageal muscle dysfunction. Those motility abnormalities sometimes normalize with treatments that reduce esophageal eosinophilia, suggesting that eosinophils can cause reversible esophageal motility disturbances, perhaps by releasing myoactive and neuroactive eosinophil products. Although achalasia uncommonly is associated with EoE as currently defined, most achalasia patients have evidence of an abnormal accumulation of eosinophils and/or their degranulation products in the esophageal muscularis propria, a location inaccessible to routine endoscopic evaluation. Achalasia is an idiopathic condition resulting from destruction of neurons in the myenteric plexus of the esophagus, and degranulating eosinophils release toxic proteins capable of destroying those neurons, thereby causing the irreversible motility abnormalities of achalasia. This report reviews data on the association of esophageal eosinophilia with achalasia and other esophageal motility abnormalities. Based on this review, we propose that EoE, like eosinophilic gastroenteritis, might have mucosal-predominant and muscle-predominant forms with different clinical manifestations. A muscle-predominant form of EoE could underlie a variety of reversible and irreversible esophageal motility disorders, including achalasia. The concept that esophageal motility abnormalities might develop from a muscle-predominant form of EoE warrants serious consideration and further investigation.