Myenteric antiplexus antibodies and class II HLA in achalasia

Research gap in esophageal achalasia: a narrative review

In recent years, new translational evidence, diagnostic techniques, and innovative therapies have shed new light on esophageal achalasia and revamped the attention on this relatively rare motility disorder. This narrative review aims to highlight the most recent progress and the areas where further research is needed. The four senior authors identified five topics commonly discussed in achalasia management: i.e. pathogenesis, role of functional lumen imaging probe in the diagnostic flow chart of achalasia, how to define the outcome of achalasia treatments, how to manage persistent chest pain after the treatment, and if achalasia patients' may benefit from a regular follow-up. We searched the bibliographic databases to identify systematic reviews, meta-analyses, randomized control trials, and original research articles in English up to December 2023. We provide a summary with the most recent findings in each of the five topics and the critical points where to address future research, such as the immune-genetic patterns of achalasia that might explain the transition among the different phenotypes, the need for a validated clinical definition of treatment success, the use of neuromodulators to manage chest pain, and the need for identifying achalasia patients at risk for cancer and who may benefit of long-term follow-up. Although undoubtedly, progress has been made on the definition and management of achalasia, unmet needs remain. Debated aspects range from mechanistic insights, symptoms, objective measure relationships, and accurate clinical responses to therapeutic interventions. Translational research is eagerly awaited to answer these unresolved questions.

Achalasia is Strongly Associated With Eosinophilic Esophagitis and Other Allergic Disorders

BACKGROUND & AIMS

Achalasia has been assumed to be an autoimmune disease targeting esophageal myenteric neurons. Recently, we proposed an alternative hypothesis that achalasia sometimes might be allergy-driven, caused by a form of eosinophilic esophagitis (EoE) in which activated eosinophils and/or mast cells infiltrating esophageal muscle release products that disrupt motility and damage myenteric neurons. To seek epidemiologic support for this hypothesis, we identified patients with achalasia in the Utah Population Database, and explored their frequency of having EoE and other allergic disorders.

METHODS

We used International Classification of Diseases codes to identify patients with achalasia and allergic disorders including EoE, asthma, atopic dermatitis, contact dermatitis, allergic rhinitis, allergic conjunctivitis, hives/urticaria, and anaphylaxis. We calculated relative risk (RR) for each allergic disorder by comparing the number observed in patients with achalasia with the expected number in individuals matched for birthyear and sex, and we performed subanalyses for patients age ≤40 versus age >40 years.

RESULTS

Among 844 patients with achalasia identified (55% female; median age at diagnosis, 58 years), 402 (47.6%) had ≥1 allergic disorder. Fifty-five patients with achalasia (6.5%) had EoE (1.67 EoE cases expected), for a RR of 32.9 (95% confidence interval, 24.8-42.8; P < .001). In 208 patients with achalasia age ≤40 years, the RR for EoE was 69.6 (95% confidence interval, 46.6-100.0; P < .001). RR also was increased significantly for all other allergic disorders evaluated (all greater than 3-fold higher than population rates).

CONCLUSIONS

Achalasia is strongly associated with EoE and other allergic disorders. These data support the hypothesis that achalasia sometimes might have an allergic etiology.

Pediatric Neurogastroenterology and Motility Disorders: What Role Does Endoscopy Play?

Although pediatric neurogastroenterology and motility (PNGM) disorders are prevalent, often debilitating, and remain challenging to diagnose and treat, this field has made remarkable progress in the last decade. Diagnostic and therapeutic gastrointestinal endoscopy emerged as a valuable tool in the management of PNGM disorders. Novel modalities such as functional lumen imaging probe, per-oral endoscopic myotomy, gastric-POEM, and electrocautery incisional therapy have changed the diagnostic and therapeutic landscape of PNGM. In this review, the authors highlight the emerging role of therapeutic and diagnostic endoscopy in esophageal, gastric, small bowel, colonic, and anorectal disorders and disorders of gut and brain axis interaction.

Update on the Diagnosis and Treatment of Achalasia

Achalasia is a rare disease of the esophagus with impaired relaxation of the lower esophageal sphincter and aperistalsis. The etiology is unknown but speculations include a viral or autoimmune etiology. All specialists dealing with swallowing and esophageal diseases should recognize the classic symptoms of dysphagia for solids/liquids, regurgitation, and choking, especially at night. High-resolution manometry is critical for the diagnosis with endoscopy and barium esophagram having a supportive role. The disease cannot be cured but most can return to near normal swallowing and a regular diet with appropriate therapy. Treatment includes smooth muscle relaxants, botulinum toxin injections to the lower sphincter, pneumatic dilation, Heller myotomy, and peroral endoscopic myotomy. One treatment does not fit all and a tailored approach through a multidiscipline team will give the best long-term outcomes.

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.

Upper Gastrointestinal Functional and Motility Disorders in Children

Children with disorders affecting the sensory and motor functions of the esophagus will present primarily with swallowing dysfunction, dysphagia, and chest pain, and those with disorders affecting the normal function of the stomach will present with symptoms like abdominal pain, nausea, and vomiting. Recent advances in the mechanisms of disease and technology have increased our understanding of gastrointestinal physiology and that knowledge has been applied to develop new diagnostic studies and therapeutic interventions. We present an overview of the clinical presentation, diagnosis, and treatment of common primary and secondary functional and motility disorders affecting the upper gastrointestinal tract in children.

Identification of differentially expressed microRNAs in primary esophageal achalasia by next-generation sequencing

Molecular knowledge regarding the primary esophageal achalasia is essential for the early diagnosis and treatment of this neurodegenerative motility disorder. Therefore, there is a need to find the main microRNAs (miRNAs) contributing to the mechanisms of achalasia. This study was conducted to determine some patterns of deregulated miRNAs in achalasia. This case-control study was performed on 52 patients with achalasia and 50 nonachalasia controls. The miRNA expression profiling was conducted on the esophageal tissue samples using the next-generation sequencing (NGS). Differential expression of miRNAs was analyzed by the edgeR software. The selected dysregulated miRNAs were additionally confirmed using the quantitative reverse transcription polymerase chain reaction (qRT-PCR). Fifteen miRNAs were identified that were significantly altered in the tissues of the patients with achalasia. Among them, three miRNAs including miR-133a-5p, miR-143-3p, and miR-6507-5p were upregulated. Also, six miRNAs including miR-215-5p, miR-216a-5p, miR-216b-5p, miR-217, miR-7641 and miR-194-5p were downregulated significantly. The predicted targets for the dysregulated miRNAs showed significant disease-associated pathways like neuronal cell apoptosis, neuromuscular balance, nerve growth factor signaling, and immune response regulation. Further analysis using qRT-PCR showed significant down-regulation of hsa-miR-217 (p-value = 0.004) in achalasia tissue. Our results may serve as a basis for more future functional studies to investigate the role of candidate miRNAs in the etiology of achalasia and their application in the diagnosis and probably treatment of the disease.

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.

Achalasia: physiology and diagnosis

Achalasia is a rare motility disorder with incomplete relaxation of the lower esophageal sphincter and ineffective contractions of the esophageal body. It has been hypothesized that achalasia does not result from only one pathway but rather involves a combination of infectious, autoimmune, and familial etiological components. On the basis of other observations, a novel hypothesis suggests that a muscular form of eosinophilic esophagitis is involved in the pathophysiology of achalasia in some patients. This appears to progressively diminish the myenteric plexus at stage III, gradually destroy it at stage II, and finally eliminate it at stage I, the most advanced and final stage of achalasia. Although high-resolution manometry has identified these three different types of achalasia, another subset of patients with a normal-appearing sphincter relaxation has been proposed. Provocative maneuvers, such as the rapid drinking challenge, have recently been demonstrated to improve diagnosis in certain borderline patients, but have to be studied in more detail. However, whether the different types of achalasia will have a long-term impact on tailored therapies is still a matter of debate. Additionally, novel aspects of the standard timed barium swallow appear to be an important adjunct of diagnosis, as it has been shown to have a diagnostic as well as a predictive value.

Whole-Genome Sequencing Identifies the Egl Nine Homologue 3 (egln3/phd3) and Protein Phosphatase 1 Regulatory Inhibitor Subunit 2 (PPP1R2P1) Associated with High-Altitude Polycythemia in Tibetans at High Altitude

Background

The hypoxic conditions at high altitudes are great threats to survival, causing pressure for adaptation. More and more high-altitude denizens are not adapted with the condition known as high-altitude polycythemia (HAPC) that featured excessive erythrocytosis. As a high-altitude sickness, the etiology of HAPC is still unclear.

Methods

In this study, we reported the whole-genome sequencing-based study of 10 native Tibetans with HAPC and 10 control subjects followed by genotyping of selected 21 variants from discovered single nucleotide variants (SNVs) in an independent cohort (232 cases and 266 controls).

Results

We discovered the egl nine homologue 3 (egln3/phd3) (14q13.1, rs1346902, P = 1.91 × 10⁻⁵) and PPP1R2P1 (Protein Phosphatase 1 Regulatory Inhibitor Subunit 2) gene (6p21.32, rs521539, P = 0.012). Our results indicated an unbiased framework to identify etiological mechanisms of HAPC and showed that egln3/phd3 and PPP1R2P1 may be associated with the susceptibility to HAPC. Egln3/phd3b is associated with hypoxia-inducible factor subunit α (HIFα). Protein Phosphatase 1 Regulatory Inhibitor is associated with reactive oxygen species (ROS) and oxidative stress.

Conclusions

Our genome sequencing conducted in Tibetan HAPC patients identified egln3/phd3 and PPP1R2P1 associated with HAPC.

INPP4B overexpression and c-KIT downregulation in human achalasia

BACKGROUND

Achalasia is a rare motility disorder characterized by myenteric neuron and interstitial cells of Cajal (ICC) abnormalities leading to deranged/absent peristalsis and lack of relaxation of the lower esophageal sphincter. The mechanisms contributing to neuronal and ICC changes in achalasia are only partially understood. Our goal was to identify novel molecular features occurring in patients with primary achalasia.

METHODS

Esophageal full-thickness biopsies from 42 (22 females; age range: 16-82 years) clinically, radiologically, and manometrically characterized patients with primary achalasia were examined and compared to those obtained from 10 subjects (controls) undergoing surgery for uncomplicated esophageal cancer (or upper stomach disorders). Tissue RNA extracted from biopsies of cases and controls was used for library preparation and sequencing. Data analysis was performed with the "edgeR" option of R-Bioconductor. Data were validated by real-time RT-PCR, western blotting and immunohistochemistry.

KEY RESULTS

Quantitative transcriptome evaluation and cluster analysis revealed 111 differentially expressed genes, with a P ≤ 10^-3 . Nine genes with a P ≤ 10^-4 were further validated. CYR61, CTGF, c-KIT, DUSP5, EGR1 were downregulated, whereas AKAP6 and INPP4B were upregulated in patients vs controls. Compared to controls, immunohistochemical analysis revealed a clear increase in INPP4B, whereas c-KIT immunolabeling resulted downregulated. As INPP4B regulates Akt pathway, we used western blot to show that phospho-Akt was significantly reduced in achalasia patients vs controls.

CONCLUSIONS & INFERENCES

The identification of altered gene expression, including INPP4B, a regulator of the Akt pathway, highlights novel signaling pathways involved in the neuronal and ICC changes underlying primary achalasia.

An original Eurasian haplotype, HLA-DRB1*14:54-DQB1*05:03, influences the susceptibility to idiopathic achalasia

Idiopathic achalasia is a relatively infrequent esophageal motor disorder for which major histocompatibility complex (MHC) genes are well-identified risk factors. However, no information about HLA-achalasia susceptibility in Mexicans has previously been reported. We studied a group of 91 patients diagnosed with achalasia and 234 healthy controls with Mexican admixed ancestry. HLA alleles and conserved extended haplotypes were analyzed using high-resolution HLA typing based on Sanger and next-generation sequencing technologies. Admixture estimates were determined using HLA-B and short tandem repeats. Results were analyzed by non-parametric statistical analysis and Bonferroni correction. P-values < 0.05 were considered significant. Patients with achalasia had 56.7% Native American genes, 24.7% European genes, 16.5% African genes and 2.0% Asian genes, which was comparable with the estimates in the controls. Significant increases in the frequencies of alleles DRB1*14:54 and DQB1*05:03 and the extended haplotypes DRB1*14:54-DQB1*05:03 and DRB1*11:01-DQB1*03:01, even after Bonferroni correction (pC<0.05), were found in the achalasia group compared to those in the controls. Concluding, the HLA class II alleles HLA-DRB1*14:54:01 and DQB1*05:03:01 and the extended haplotype are risk factors for achalasia in mixed-ancestry Mexican individuals. These results also suggest that the HLA-DRB1*14:54-DQB1*05:03 haplotype was introduced by admixture with European and/or Asian populations.

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.

Achalasia following reflux disease: coincidence, consequence, or accommodation? An experience-based literature review

Achalasia is a motility disorder of the esophagus characterized by the defective peristaltic activity of the esophageal body and impaired relaxation of the lower esophageal sphincter due to the degeneration of the inhibitory neurons in the myenteric plexus of the esophageal wall. The histopathological and pathophysiological changes in achalasia have been well described. However, the exact etiological factors leading to the disease still remain unclear. Currently, achalasia is believed to be a multifactorial disease, involving both extrinsic and intrinsic factors. Based on our experience and the review of literature, we believe that gastroesophageal reflux disease (GERD) might be one of the triggering factors leading to the development of achalasia. However, it is also stated that the two diseases can simultaneously appear independently from each other. Considering the large number and routine treatment of patients with GERD and achalasia, the rare combination of the two may even remain unnoticed; thus, the analysis of larger patient groups with this entity is not feasible. In this context, we report four cases where long-standing reflux symptoms preceded the development of achalasia. A literature review of the available data is also given. We hypothesize that achalasia following the chronic acid exposure of the esophagus is not accidental but either a consequence of a chronic inflammation or a protective reaction of the organism in order to prevent aspiration and lessen reflux-related symptoms. This hypothesis awaits further clinical confirmation.

Muscle layer histopathology and manometry pattern of primary esophageal motility disorders including achalasia

BACKGROUND

Histopathology of muscularis externa in primary esophageal motility disorders has been characterized previously. We aimed to correlate the results of high-resolution manometry with those of histopathology.

METHODS

During peroral endoscopic myotomy, peroral esophageal muscle biopsy was performed in patients with primary esophageal motility disorders. Immunohistochemical staining for c-kit was performed to assess the interstitial cells of Cajal (ICCs). Hematoxylin Eosin and Azan-Mallory staining were used to detect muscle atrophy, inflammation, and fibrosis, respectively.

KEY RESULTS

Slides from 30 patients with the following motility disorders were analyzed: achalasia (type I: 14, type II: 5, type III: 3), one diffuse esophageal spasm (DES), two outflow obstruction (OO), four jackhammer esophagus (JE), and one nutcracker esophagus (NE). ICCs were preserved in high numbers in type III achalasia (n=9.4±1.2 cells/high power field [HPF]), compared to types I (n=3.7±0.3 cells/HPF) and II (n=3.5±1.0 cells/HPF). Moreover, severe fibrosis was only observed in type I achalasia and not in other types of achalasia, OO, or DES. Four of five patients with JE and NE had severe inflammation with eosinophilic infiltration of the esophageal muscle layer (73.8±50.3 eosinophils/HPF) with no epithelial eosinophils. One patient with JE showed a visceral myopathy pattern.

CONCLUSIONS & INFERENCES

Compared to types I and II, type III achalasia showed preserved ICCs, with variable data regarding DES and OO. In disorders considered as primary esophageal motility disorders, a disease category exists, which shows eosinophilic infiltration in the esophageal muscle layer with no eosinophils in the epithelium.

Gene expression of muscular and neuronal pathways is cooperatively dysregulated in patients with idiopathic achalasia

Idiopathic achalasia is characterized by the absence of peristalsis secondary to loss of neurons in the myenteric plexus that hampers proper relaxation of the lower esophageal sphincter. Achalasia can be considered a multifactorial disorder as it occurs in related individuals and is associated with HLA class II genes, thereby suggesting genetic influence. We used microarray technology and advanced in-silico functional analyses to perform the first genome-wide expression profiling of mRNA in tissue samples from 12 achalasia and 5 control patients. It revealed 1,728 differentially expressed genes, of these, 837 (48.4%) were up-regulated in cases. In particular, genes participating to the smooth muscle contraction biological function were mostly up-regulated. Functional analysis revealed a significant enrichment of neuronal/muscular and neuronal/immunity processes. Upstream regulatory analysis of 180 genes involved in these processes suggested TLR4 and IL18 as critical key-players. Two functional gene networks were significantly over-represented: one involved in organ morphology, skeletal muscle system development and function, and neurological diseases, and the other participating in cell morphology, humoral immune response and cellular movement. These results highlight on pivotal genes that may play critical roles in neuronal/muscular and neuronal/immunity processes, and that may contribute to the onset and development of achalasia.

Achalasia: From Bench to Peroral Endoscopic Myotomy

Achalasia is a primary esophageal motility disorder with an estimated annual incidence of 1 per 100,000 persons. It is characterized by the absence of esophageal peristalsis and failure of the lower esophageal sphincter (LES) to relax upon swallowing, resulting in progressively severe dysphagia for solids and liquids, regurgitation, aspiration, chest pain and weight loss. Achalasia results from a loss of enteric neurons, most likely due to an autoimmune reaction in patients with a particular immunogenetic background. To date, 3 manometric subtypes have been identified based on high resolution manometry. To what extent these subtypes also indicate differences in underlying pathophysiological mechanisms is however unclear. As achalasia cannot be cured, treatment is confined to disruption of the LES to improve bolus passage and thereby relieving symptoms. The 2 most commonly used treatment modalities available for this purpose include pneumodilation and laparoscopic Heller myotomy. Both treatments have been shown repeatedly to be successful; however, success rates decline in time, most likely due to progression of the disease. A recent European randomized trial provides objective data indicating that both treatments are equally effective. In view of these data and the low incidence of the disease, the choice between these 2 treatments should be based on the expertise and experience available. Recently, excellent short-term success rates have been reported with a new endoscopic technique, that is, peroral endoscopic myotomy. However, longer follow-up data are absolutely needed before accepting this technique as a new treatment option for achalasia in clinical practice.

Clinical management of achalasia: current state of the art

Achalasia is a primary disorder of esophageal motility. It classically presents with dysphagia to both solids and liquids but may be accompanied by regurgitation and chest pain. The gold standard for the diagnosis of achalasia is esophageal motility testing with manometry, which often reveals aperistalsis of the esophageal body and incomplete lower esophageal sphincter relaxation. The diagnosis is aided by complimentary tests, such as esophagogastroduodenoscopy and contrast radiography. Esophagogastroduodenoscopy is indicated to rule out mimickers of the disease known as “pseudoachalasia” (eg, malignancy). Endoscopic appearance of a dilated esophagus with retained food or saliva and a puckered lower esophageal sphincter should raise suspicion for achalasia. Additionally, barium esophagography may reveal a dilated esophagus with a distal tapering giving it a “bird’s beak” appearance. Multiple therapeutic modalities aid in the management of achalasia, the decision of which depends on operative risk factors. Conventional treatments include medical therapy, botulinum toxin injection, pneumatic dilation, and Heller myotomy. The last two are defined as the most definitive treatment options. New emerging therapies include peroral endoscopic myotomy, placement of self-expanding metallic stents, and endoscopic sclerotherapy.

Histopathologic patterns among achalasia subtypes

BACKGROUND

Achalasia has three distinct manometric phenotypes. This study aimed to determine if there were corresponding histopathologic patterns.

METHODS

We retrospectively examined surgical muscularis propria biopsies obtained from 46 patients during laparoscopic esophagomyotomy. Pre-operative (conventional) manometry tracings were reviewed by two expert gastroenterologists who categorized patients into Chicago Classification subtypes. Pathology specimens were graded on degree of neuronal loss, inflammation, fibrosis, and muscle changes.

KEY RESULTS

Manometry studies were categorized as follows: type I (n = 20), type II (n = 20), type III (n = 3), and esophagogastric junction outflow obstruction (EGJOO) (n = 3). On histopathology, complete ganglion cell loss occurred in 74% of specimens, inflammation in 17%, fibrosis in 11%, and muscle atrophy in 2%. Comparing type I and type II specimens, there was a statistically significant greater proportion of type I specimens with aganglionosis (19/20 vs 13/20, p = 0.044) and a statistically significant greater degree of ganglion cell loss in type I specimens (Wilcoxon Rank-Sum, p = 0.016). CD3(+) /CD8(+) cytotoxic T cells represented the predominant inflammatory infiltrate on immunohistochemistry. Three patients had completely normal appearing tissue (1 each in type II, type III, EGJOO).

CONCLUSIONS & INFERENCES

The greater degree, but similar pattern, of ganglion cell loss observed in type I compared to type II achalasia specimens suggests that type I achalasia represents a progression from type II achalasia. The spectrum of histopathologic findings - from complete neuronal loss to lymphocytic inflammation to apparently normal histopathology - emphasizes that 'achalasia' represents a pathogenically heterogeneous patient group with the commonality being EGJ outflow obstruction.

Idiopathic (primary) achalasia: a review

Idiopathic achalasia is a primary esophageal motor disorder characterized by loss of esophageal peristalsis and insufficient lower esophageal sphincter relaxation in response to deglutition. Patients with achalasia commonly complain of dysphagia to solids and liquids, bland regurgitation often unresponsive to an adequate trial of proton pump inhibitor, and chest pain. Weight loss is present in many, but not all patients. Although the precise etiology is unknown, it is often thought to be either autoimmune, viral immune, or neurodegenerative. The diagnosis is based on history of the disease, barium esophagogram, and esophageal motility testing. Endoscopic assessment of the gastroesophageal junction and gastric cardia is necessary to rule out malignancy. Newer diagnostic modalities such as high resolution manometry help in predicting treatment response in achalasia based on esophageal pressure topography patterns identifying three phenotypes of achalasia (I-III) and outcome studies suggest better treatment response with types I and II compared to type III. Although achalasia cannot be permanently cured, excellent outcomes are achieved in over 90 % of patients. Current medical and surgical therapeutic options (pneumatic dilation, endoscopic and surgical myotomy, and pharmacologic agents) aim at reducing the LES pressure and facilitating esophageal emptying by gravity and hydrostatic pressure of retained food and liquids. Either graded pneumatic dilatation or laparoscopic surgical myotomy with a partial fundoplication are recommended as initial therapy guided by patient age, gender, preference, and local institutional expertise. The prognosis in achalasia patients is excellent. Most patients who are appropriately treated have a normal life expectancy but the disease does recur and the patient may need intermittent treatment.

The Pathogenesis and Management of Achalasia: Current Status and Future Directions

Achalasia is an esophageal motility disorder that is commonly misdiagnosed initially as gastroesophageal reflux disease. Patients with achalasia often complain of dysphagia with solids and liquids but may focus on regurgitation as the primary symptom, leading to initial misdiagnosis. Diagnostic tests for achalasia include esophageal motility testing, esophagogastroduodenoscopy and barium swallow. These tests play a complimentary role in establishing the diagnosis of suspected achalasia. High-resolution manometry has now identified three subtypes of achalasia, with therapeutic implications. Pneumatic dilation and surgical myotomy are the only definitive treatment options for patients with achalasia who can undergo surgery. Botulinum toxin injection into the lower esophageal sphincter should be reserved for those who cannot undergo definitive therapy. Close follow-up is paramount because many patients will have a recurrence of symptoms and require repeat treatment.

Achalasia--An Autoimmune Inflammatory Disease: A Cross-Sectional Study

Idiopathic achalasia is a disease of unknown etiology. The loss of myenteric plexus associated with inflammatory infiltrates and autoantibodies support the hypothesis of an autoimmune mechanism. Thirty-two patients diagnosed by high-resolution manometry with achalasia were included. Twenty-six specimens from lower esophageal sphincter muscle were compared with 5 esophagectomy biopsies (control). Immunohistochemical (biopsies) and flow cytometry (peripheral blood) analyses were performed. Circulating anti-myenteric autoantibodies were evaluated by indirect immunofluorescence. Herpes simplex virus-1 (HSV-1) infection was determined by in situ hybridization, RT-PCR, and immunohistochemistry. Histopathological analysis showed capillaritis (51%), plexitis (23%), nerve hypertrophy (16%), venulitis (7%), and fibrosis (3%). Achalasia tissue exhibited an increase in the expression of proteins involved in extracellular matrix turnover, apoptosis, proinflammatory and profibrogenic cytokines, and Tregs and Bregs versus controls (P < 0.001). Circulating Th22/Th17/Th2/Th1 percentage showed a significant increase versus healthy donors (P < 0.01). Type III achalasia patients exhibited the highest inflammatory response versus types I and II. Prevalence of both anti-myenteric antibodies and HSV-1 infection in achalasia patients was 100% versus 0% in controls. Our results suggest that achalasia is a disease with an important local and systemic inflammatory autoimmune component, associated with the presence of specific anti-myenteric autoantibodies, as well as HSV-1 infection.

Genetic variation in the lymphotoxin-α (LTA)/tumour necrosis factor-α (TNFα) locus as a risk factor for idiopathic achalasia

BACKGROUND

Idiopathic achalasia is a rare motor disorder of the oesophagus characterised by neuronal loss at the lower oesophageal sphincter. Achalasia is generally accepted as a multifactorial disorder with various genetic and environmental factors being risk-associated. Since genetic factors predisposing to achalasia have been poorly documented, we assessed whether single nucleotide polymorphisms (SNPs) in genes mediating immune response and neuronal function contribute to achalasia susceptibility.

METHODS

391 SNPs covering 190 immune and 67 neuronal genes were genotyped in an exploratory cohort from Central Europe (589 achalasia patients, 794 healthy volunteers (HVs)). 24 SNPs (p<0.05) were validated in an Italian (160 achalasia patients, 278 HVs) and Spanish cohort (281 achalasia patients, 296 HVs). 16 SNPs in linkage disequilibrium (LD) with rs1799724 (r(2)>0.2) were genotyped in the exploratory cohort. Genotype distributions of patients (1030) and HVs (1368) were compared using Cochran-Armitage trend test.

RESULTS

The rs1799724 SNP located between the lymphotoxin-α (LTA) and tumour necrosis factor-α (TNFα) genes was significantly associated with achalasia and withstood correction for testing multiple SNPs (p=1.17E-4, OR=1.41 (1.18 to 1.67)). SNPs in high LD with rs1799724 were associated with achalasia. Three SNPs located in myosin-5B, adrenergic receptor-β-2 and interleukin-13 (IL13) showed nominally significant association to achalasia that was strengthened by replication.

CONCLUSIONS

Our study provides evidence for rs1799724 at the LTA/TNFα locus as a susceptibility factor for idiopathic achalasia. Additional studies are needed to dissect which genetic variants in the LTA/TNFα locus are disease-causing and confirm other variants as potential susceptibility factors for achalasia.

Esophageal motility disorder achalasia

PURPOSE OF REVIEW

Although not a common disease, the last several years have had exciting breakthroughs in better defining the pathophysiology of achalasia, classifying the disease with high-resolution manometry and potentially exciting new treatments.

RECENT FINDINGS

The introduction of high-resolution manometry with detailed assessment of lower esophageal sphincter function and peristalsis has made it possible to classify achalasia into three subtypes. This becomes clinically important as patients with type II achalasia do best with both pneumatic dilation and surgical myotomy, whereas type III achalasia may respond better to surgery. The first multicenter randomized controlled trial published by the European Achalasia Trial group reported similar excellent outcomes over a 2-year follow-up with both pneumatic dilation and laparoscopic myotomy in a study involving nearly 200 achalasia patients. Although longer follow-up is required, this supports the continued use of pneumatic dilation for treating achalasia. Finally, the novel endoscopic technique of peroral endoscopic myotomy is a promising new treatment option for achalasia, but it requires increased experiences and careful evaluation before widespread application.

SUMMARY

These are exciting times in the diagnosis and treatment of achalasia, which will definitely improve patient treatment outcomes. However, we still await breakthroughs in the basic science arena to identify the actual cause of achalasia.

Family case of achalasia cardia: Case report and review of literature

Achalasia cardia is an idiopathic disease that occurs as a result of inflammation and degeneration of myenteric plexi leading to the loss of postganglionic inhibitory neurons required for relaxation of the lower esophageal sphincter and peristalsis of the esophagus. The main symptoms of achalasia are dysphagia, regurgitation, chest pain and weight loss. At present, there are three main hypotheses regarding etiology of achalasia cardia which are under consideration, these are genetic, infectious and autoimmune. Genetic theory is one of the most widely discussed. Case report given below represents an inheritable case of achalasia cardia which was not diagnosed for a long time in an 81-year-old woman and her 58-year-old daughter.

Achalasia

Achalasia is a rare motility disorder of the oesophagus characterised by loss of enteric neurons leading to absence of peristalsis and impaired relaxation of the lower oesophageal sphincter. Although its cause remains largely unknown, ganglionitis resulting from an aberrant immune response triggered by a viral infection has been proposed to underlie the loss of oesophageal neurons, particularly in genetically susceptible individuals. The subsequent stasis of ingested food not only leads to symptoms of dysphagia, regurgitation, chest pain, and weight loss, but also results in an increased risk of oesophageal carcinoma. At present, pneumatic dilatation and Heller myotomy combined with an anti-reflux procedure are the treatments of choice and have comparable success rates. Per-oral endoscopic myotomy has recently been introduced as a new minimally invasive treatment for achalasia, but there have not yet been any randomised clinical trials comparing this option with pneumatic dilatation and Heller myotomy.

The spectrum of achalasia: lessons from studies of pathophysiology and high-resolution manometry

High-resolution manometry and recently described analysis algorithms, summarized in the Chicago Classification, have increased the recognition of achalasia. It has become apparent that the cardinal feature of achalasia, impaired lower esophageal sphincter relaxation, can occur in several disease phenotypes: without peristalsis, with premature (spastic) distal esophageal contractions, with panesophageal pressurization, or with peristalsis. Any of these phenotypes could indicate achalasia; however, without a disease-specific biomarker, no manometric pattern is absolutely specific. Laboratory studies indicate that achalasia is an autoimmune disease in which esophageal myenteric neurons are attacked in a cell-mediated and antibody-mediated immune response against an uncertain antigen. This autoimmune response could be related to infection of genetically predisposed subjects with herpes simplex virus 1, although there is substantial heterogeneity among patients. At one end of the spectrum is complete aganglionosis in patients with end-stage or fulminant disease. At the opposite extreme is type III (spastic) achalasia, which has no demonstrated neuronal loss but only impaired inhibitory postganglionic neuron function; it is often associated with accentuated contractility and could be mediated by cytokine-induced alterations in gene expression. Distinct from these extremes is progressive plexopathy, which likely arises from achalasia with preserved peristalsis and then develops into type II achalasia and then type I achalasia. Variations in its extent and rate of progression are likely related to the intensity of the cytotoxic T-cell assault on the myenteric plexus. Moving forward, we need to integrate the knowledge we have gained into treatment paradigms that are specific for individual phenotypes of achalasia and away from the one-size-fits-all approach.

The management of esophageal achalasia: from diagnosis to surgical treatment

The goal of this review is to illustrate our approach to patients with achalasia in terms of preoperative evaluation and surgical technique. Indications, patient selection and management are herein discussed. Specifically, we illustrate the pathogenetic theories and diagnostic algorithm with current up-to-date techniques to diagnose achalasia and its manometric variants. Finally, we focus on the therapeutic approaches available today: medical and surgical. A special emphasis is given on the surgical treatment of achalasia and we provide the reader with a detailed description of our pre and postoperative management.

Remission of arthritis after esophagectomy in three patients with severe achalasia

In the 1960s and 1970s, intestinal bypass surgery was performed to treat patients with extreme obesity. However, this is now done with great restriction due to the risk of complications, for instance, polyarthritis. An association between severe achalasia and arthritis has also been described, but very few articles on this topic are cited in PubMed, and most of the published case reports are old. In this article, we present a retrospective case series of three patients with severe achalasia and arthritis from the departments of rheumatology and surgery at a university hospital. The complaints from the esophagus as well as arthritis were resolved after esophagectomy and esophageal reconstruction. We conclude that severe achalasia can be associated with arthritis, and both can be cured by esophageal reconstruction. Thus, we want to remind of this rare, but probably largely unrecognized, association between achalasia and joint disease.

Immunohistochemical study of the muscularis externa of the esophagus in achalasia patients

The etiology of achalasia is believed to be the neuropathy associated with chronic inflammation of the nerve plexus, but the cause of plexus inflammation is unknown. The purpose of this study was to evaluate the pathophysiology of achalasia by examining the muscularis externa of the esophagus. We used the muscularis externa of the esophagus of 62 patients with achalasia (median 44 years, male : female 32:30) who underwent surgical treatment (achalasia group) and of 10 patients (median 65.5 years, male : female 9:1) who underwent esophagectomy for thoracic esophageal cancer (control group) to perform immunohistochemical staining with S-100, CD43, c-kit (CD117), n-NOS, vasoactive intestinal polypeptide (VIP), and ubiquitin. The cell counts that were positive for S-100, n-NOS, VIP, and ubiquitin were significantly lower in the achalasia group compared with the control group (P < 0.001, P= 0.001, P < 0.001, and P= 0.001, respectively). There were no statistically significant differences with respect to CD43 and c-kit staining (P= 0.586 and P= 0.209, respectively). In conclusion, the pathophysiology of achalasia is therefore considered to be an impaired production of NO and VIP, which both affect interstitial cell of Cajal and smooth muscles, and this impairment is therefore considered to play a role in the pathophysiology of achalasia.

Circulating antimyenteric autoantibodies in Tunisian patients with idiopathic achalasia

The physiopathology of idiopathic achalasia is still unknown. The description of circulating antimyenteric autoantibodies (CAA), directed against enteric neurons in sera of patients, suggests an autoimmune process. Recent data showed controversies according to the existence and the significance of CAA. The aims of this study were to investigate whether CAA are detected in Tunisian patients with idiopathic achalasia and to look for associated clinical or manometrical factors with CAA positivity. Twenty-seven patients with idiopathic achalasia and 57 healthy controls were prospectively studied. CAA were assessed by indirect immunofluorescence on intestinal monkey tissue sections. Western blot on primate cerebellum protein extract and dot technique with highly purified recombinant neuronal antigens (Hu, Ri, and Yo) were further used to analyze target antigens of CAA. CAA were significantly increased in achalasia patients compared with controls when considering nuclear or cytoplasmic fluorescence patterns. (33% vs. 12%, P = 0.03 and 48% vs. 23%, P = 0.001 respectively). By immunoblot analysis, CAA did not target neuronal antigens, however 52/53 and 49 kDa bands were consistently detected. CAA positivity was not correlated to specific clinical features. The results are along with previous studies demonstrating high CAA prevalence in achalasia patients. When reviewing technical protocols and interpretation criteria, several discrepancies which could explain controversies between studies were noted.

Pathogenesis of achalasia cardia

Achalasia cardia is one of the common causes of motor dysphagia. Though the disease was first described more than 300 years ago, exact pathogenesis of this condition still remains enigmatic. Pathophysiologically, achalasia cardia is caused by loss of inhibitory ganglion in the myenteric plexus of the esophagus. In the initial stage, degeneration of inhibitory nerves in the esophagus results in unopposed action of excitatory neurotransmitters such as acetylcholine, resulting in high amplitude non-peristaltic contractions (vigorous achalasia); progressive loss of cholinergic neurons over time results in dilation and low amplitude simultaneous contractions in the esophageal body (classic achalasia). Since the initial description, several studies have attempted to explore initiating agents that may cause the disease, such as viral infection, other environmental factors, autoimmunity, and genetic factors. Though Chagas disease, which mimics achalasia, is caused by an infective agent, available evidence suggests that infection may not be an independent cause of primary achalasia. A genetic basis for achalasia is supported by reports showing occurrence of disease in monozygotic twins, siblings and other first-degree relatives and occurrence in association with other genetic diseases such as Down’s syndrome and Parkinson’s disease. Polymorphisms in genes encoding for nitric oxide synthase, receptors for vasoactive intestinal peptide, interleukin 23 and the ALADIN gene have been reported. However, studies on larger numbers of patients and controls from different ethnic groups are needed before definite conclusions can be obtained. Currently, the disease is believed to be multi-factorial, with autoimmune mechanisms triggered by infection in a genetically predisposed individual leading to degeneration of inhibitory ganglia in the wall of the esophagus.

The Kagoshima consensus on esophageal achalasia

Esophageal achalasia is a primary esophageal motility disorder characterized by lack of peristalsis and a lower esophageal sphincter that fails to relax appropriately in response to swallowing. This article summarizes the most salient issues in the diagnosis and management of achalasia as discussed in a symposium that took place in Kagoshima, Japan, in September 2010 under the auspices of the International Society for Diseases of the Esophagus.

2011 update on esophageal achalasia

There have been some breakthroughs in the diagnosis and treatment of esophageal achalasia in the past few years. First, the introduction of high-resolution manometry with pressure topography plotting as a new diagnostic tool has made it possible to classify achalasia into three subtypes. The most favorable outcome is predicted for patients receiving treatment for type II achalasia (achalasia with compression). Patients with typeI(classic achalasia) and type III achalasia (spastic achalasia) experience a less favorable outcome. Second, the first multicenter randomized controlled trial published by the European Achalasia Trial group reported 2-year follow-up results indicating that laparoscopic Heller myotomy was not superior to endoscopic pneumatic dilation (PD). Although the follow-up period was not long enough to reach a convincing conclusion, it merits the continued use of PD as a generally available technique in gastroenterology. Third, the novel endoscopic technique peroral endoscopic myotomy is a promising option for treating achalasia, but it requires increased experience and cautious evaluation. Despite all this good news, the bottom line is a real breakthrough from the basic studies to identify the actual cause of achalasia that may impede treatment success is still anticipated.

Surgical treatment for achalasia: when should it be performed, and for which patients?

Achalasia is a rare motor disorder of the esophagus, characterized by the absence of peristalsis and impaired swallow-induced relaxation. In the past decade, evidence has been accumulated suggesting that achalasia may be an immune-mediated inflammatory disorder. With the advent of minimally invasive surgery, laparoscopic Heller myotomy (LHM) has slowly shifted the treatment of achalasia toward the greater use of surgical therapy. The goal of both surgical and nonsurgical treatment is to eliminate the outflow obstruction afforded by a nonrelaxing sphincter, relieving dysphagia and maintaining a barrier against gastroesophageal reflux (GER). Endoscopic botulinum toxin injection (EBTI) is safe, easy to perform, inexpensive, and effective in aged patients, and it is especially effective when the lower esophageal pressure is hypertonic. This therapeutic option is reserved for patients too ill to undergo any surgical procedure. Pneumatic dilation (PD) has been shown to be an effective and inexpensive treatment with few adverse effects. The long-term success rate of PD seems to drop progressively over time. Heller myotomy (HM) has shown the best clinical efficacy in achalasia as a first-line treatment. Multiple endoscopic treatments are associated with poorer outcomes after HM. EBTI also makes LHM more difficult and results in a worse surgical outcome. The inferior symptomatic outcomes after thoracoscopic HM may be caused by the difficulty in extending an adequate myotomy onto the stomach from the chest and the inability to create a fundoplication. LHM with Dor's fundoplication (LHM + Dor) is effective and is safer procedure for avoiding GER, dysphagia, mucosal perforation, and a pseudodiverticulum. LHM + Dor is also effective in the presence of sigmoid achalasia, but the clinical result is not as good as nonsigmoid achalasia. A few patients need esophagectomy for surgical failure of HM. However, considering the risk of esophagectomy, LHM + Dor is the first treatment option for patients with achalasia regardless of the degree of esophageal dilatation. This procedure is therefore considered to be an effective and safe treatment for patients of any age or with any condition.

Association of IL10 promoter polymorphisms with idiopathic achalasia

Idiopathic achalasia is an esophageal motor disorder of unknown etiology. A wealth of evidence supports the concept that achalasia is an immune-mediated disease. According to this evidence, achalasia has been significantly associated with specific alleles of the human leukocyte antigen class II, PTPN22 and IL23R. Several studies have demonstrated association of the IL10 gene with different inflammatory disorders. Our aim was to evaluate the role of functional IL10 promoter polymorphisms in susceptibility to idiopathic achalasia. A case-control study was performed with the -1082, -819, and -592 IL10 promoter polymorphisms in 282 patients and 529 controls and in an independent replication set of 75 patients and 575 controls. The GCC haplotype of the IL10 promoter was reported to be associated with a lower risk of achalasia in the discovery sample (odds ratio [OR] = 0.79, 95% confidence interval [CI] = 0.64-0.98, p = 0.029). This association was validated in a replication set (OR = 0.69, 95% CI = 0.48-1.00, p = 0.04). In the combined analysis no heterogeneity was observed between the 2 sample sets and the GCC haplotype was significantly associated with the disease (OR(MH) = 0.76, 95% CI = 0.63-0.91, p = 0.003). Our results provide the first evidence for an association between IL10 promoter polymorphisms and idiopathic achalasia, suggesting that the interleukin-10 cytokine may contribute to the pathogenesis of this disease.

Genetic evaluation of ALADIN gene in early-onset achalasia and alacrima patients

Background/Aims

ALADIN gene has been known to cause achalasia, alacrima, adrenal abnormalities and a progressive neurological syndrome. A considerable proportion of achalasia patients has been known to show alacrima (decreased secretion of tear). However, the genetic mechanism between achalasia and alacrima has not been defined yet. We postulated that ALADIN gene may be involved in the occurrence of early-onset achalasia; thus, we investigated the correlation of ALADIN gene in early-onset achalasia patients.

Methods

From 1989 to 2007, patients who were diagnosed as primary achalasia before age 35 were enrolled. All of the enrolled patients were asked for (1) blood sampling for DNA, (2) Shirmer test and (3) dysphagia questionnaires.

Results

The ALADIN gene in exon 1, 2, 10, 11 and 12 from 19 patients was investigated (M:F = 12:7). The mean age of patients at diagnosis was 27 ± 5 (15-35) years old. Eight out of 19 (42%) showed alacrima by the positive Shirmer test. In spite of thorough exam in the genetic study, there was no definite abnormal genetic finding in this study.

Conclusions

A considerable number of achalasia patients showed alacrima. Due to the limitation of this study, it is difficult to conclude that early-onset achalasia may have significant correlations with the ALADIN gene.

Management of achalasia

Several theories on the etiology and pathophysiology of achalasia have been reported but, to date, it is widely accepted that loss of peristalsis and absence of swallow-induced relaxation of the lower esophageal sphincter are the main functional abnormalities. Treatment of achalasia often aims to alleviate the symptoms of achalasia and not to correct the underlying disorder. Medical therapy has poor efficacy, so patients who are good surgical candidates should be offered either laparoscopic myotomy or pneumatic balloon dilatation. Their own preference should be included in the decision-making process, and treatment should meet the local expertise with these procedures. Laparoscopic surgical esophagomyotomy is a safe and effective modality. It can be considered as initial management or as secondary treatment if the patient does not respond to less invasive modalities. Pneumatic dilatation has proven to be a safe, effective, and durable modality of treatment when performed by experienced individuals, and appears to be the most cost-effective alternative. For patients with multiple comorbidities and for elderly patients, who are not good surgical candidates, endoscopic injection of botulinum toxin should be considered a safe and effective procedure. However, its positive effect diminishes over time, and the need for multiple repeated sessions must be taken into consideration. In the management of patients with achalasia, nutritional aspects play an important role. When lifestyle changes are insufficient, it is necessary to proceed to percutaneous gastrostomy under radiological guidance. In the future, intraluminal myotomy or endoscopic mucosectomy will possibly be an option. Further studies are needed to investigate the role of immunosuppressive therapies in those cases in which an autoimmune etiology is suspected.

Achalasia and viral infection: new insights from veterinary medicine

Achalasia is a serious disorder in which the movement of food and liquids through the esophagus is impaired. It is currently thought to be caused by an inflammatory process that destroys neurons in myenteric ganglia, which affect peristalsis in the esophagus. The factor(s) that precipitate this inflammatory process are unknown; possibilities include environmental agents (such as microbes or toxins) and/or cell-mediated autoimmune reactivity. Recently, infection with a newly described bornavirus has been strongly linked to a disease of exotic birds that displays many striking similarities to achalasia. These findings demonstrate that viruses can induce achalasia-like pathophysiology and have renewed interest in the search for infectious agents in this enigmatic human disease.

Achalasia: incidence, prevalence and survival. A population-based study

BACKGROUND

Studies of achalasia epidemiology are important as they often yield new insights into disease etiology. In this study, our objective was to carry out the first North American population-based study of achalasia epidemiology using a governmental administrative database.

METHODS

All residents in the province of Alberta, Canada receive universal healthcare coverage as a benefit. The provincial health ministry, Alberta Health and Wellness, maintains a central stakeholder database of patient demographic information and physician billing claims. We defined an achalasia case as a billing claim submitted for the years 1996-2007 with an ICD-9-CM code of 530.0 or 530 and a Canadian Classification of Procedure treatment code of 54.92A (endoscopic balloon dilation) or 54.6 (esophagomyotomy). A preliminary validation study of the case definition demonstrated a sensitivity of 85% and specificity of 99% for known cases and controls.

KEY RESULTS

A total of 463 achalasia cases were identified from 1995 to 2008 (59.6% males). Mean age at diagnosis was 53.1 years. In 2007, the achalasia incidence was 1.63/100,000 (95% CI 1.20, 2.06) and the prevalence was 10.82/100,000 (95% CI 9.70, 11.93). We observed a steady increase in the overall prevalence rate from 2.51/100,000 in 1996 to 10.82/100,000 in 2007. Survival of achalasia cases was significantly less than age-sex matched population controls (P < 0.0001).

CONCLUSIONS & INFERENCES

Using a population-based approach, the incidence and prevalence of treated achalasia is 1.63/100,000 and 10.82/100,000, respectively. The disease appears to have a stable incidence but a rising prevalence. Survival of achalasia cases is significantly less than age-matched healthy controls.

Achalasia: will genetic studies provide insights?

Despite increasing understanding of the pathophysiology of achalasia, the etiology of this esophageal motility disorder remains largely unknown. However, the occurrence of familial achalasia and its association with well-defined genetic syndromes suggest the involvement of genetic factors. Mutant mouse models display gastrointestinal disturbances that are similar to those observed in achalasia patients. The candidate gene approach has revealed some promising results; however, it has not established conclusive links to specific genes so far. The aim of this review was to summarize current knowledge of the genetics of achalasia. We also discuss the extent to which our understanding of achalasia is likely to be enhanced through future molecular genetic research.

Achalasia: will genetic studies provide insights?

Despite increasing understanding of the pathophysiology of achalasia, the etiology of this esophageal motility disorder remains largely unknown. However, the occurrence of familial achalasia and its association with well-defined genetic syndromes suggest the involvement of genetic factors. Mutant mouse models display gastrointestinal disturbances that are similar to those observed in achalasia patients. The candidate gene approach has revealed some promising results; however, it has not established conclusive links to specific genes so far. The aim of this review was to summarize current knowledge of the genetics of achalasia. We also discuss the extent to which our understanding of achalasia is likely to be enhanced through future molecular genetic research.

Achalasia - an update

Achalasia is an esophageal motility disorder of unknown cause, characterized by aperistalsis of the esophageal body and impaired lower esophageal sphincter relaxation. Patients present at all ages, primarily with dysphagia for solids/liquids and bland regurgitation. The diagnosis is suggested by barium esophagram and confirmed by esophageal manometry. Achalasia cannot be cured. Instead, our goal is to relieve symptoms, improve esophageal emptying and prevent the development of megaesophagus. The most successful therapies are pneumatic dilation and surgical myotomy. The overall success rate of graded pneumatic dilation is 78%, with women and older patients responding best. Laparoscopic myotomy, usually combined with a partial fundoplication, has an overall success rate of 87%. Young patients, especially men, are the best candidates for surgical myotomy. Botulinum toxin injection into the lower esophageal sphincter and smooth muscle relaxants are usually reserved for older patients or those with co-morbid illness. The prognosis for achalasia patients to return to near normal swallowing is good, but the disease is rarely "cured" with a single procedure and intermittent touch-up procedures may be required.