Common variants in the HLA-DQ region confer susceptibility to idiopathic achalasia

Achalasia-an unnecessary long way to diagnosis

Although achalasia presents with typical symptoms such as dysphagia, regurgitation, weight loss, and atypical chest pain, the time until first diagnosis often takes years and is frustrating for patients and nevertheless associated with high costs for the healthcare system. A total of 563 patients were interviewed with confirmed diagnosis of achalasia regarding their symptoms leading to diagnosis along with past clinical examinations and treatments. Included were patients who had undergone their medical investigations in Germany. Overall, 527 study subjects were included (male 46%, female 54%, mean age at time of interview 51 ± 14.8 years). Dysphagia was present in 86.7%, regurgitation in 82.9%, atypical chest pain in 79%, and weight loss in 58% of patients before diagnosis. On average, it took 25 months (Interquartile Range (IQR) 9-65) until confirmation of correct diagnosis of achalasia. Though, diagnosis was confirmed significantly quicker (35 months IQR 9-89 vs. 20 months IQR 8-53; p < 0.01) in the past 15 years. The majority (72.1%) was transferred to three or more specialists. Almost each patient underwent at least one esophagogastroduodenoscopy (94.2%) and one radiological assessment (89.3%). However, esophageal manometry was performed in 70.4% of patients only. The severity of symptoms was independent with regard to duration until first diagnosis (Eckardt score 7.14 ± 2.64 within 12 months vs. 7.29 ± 2.61 longer than 12 months; P = 0.544). Fifty-five percent of the patients primarily underwent endoscopic dilatation and 37% a surgical myotomy. Endoscopic dilatation was realized significantly faster compared to esophageal myotomy (1 month IQR 0-4 vs. 3 months IQR 1-11; p < 0.001). Although diagnosis of achalasia was significantly faster in the past 15 years, it still takes almost 2 years until the correct diagnosis of achalasia is confirmed. Alarming is the fact that although esophageal manometry is known as the gold standard to differentiate primary motility disorders, only three out of four patients had undergone this diagnostic pathway during their diagnostic work-up. Better education of medical professionals and broader utilization of highly sensitive diagnostic tools, such as high-resolution manometry, are strictly necessary in order to correctly diagnose affected patients and to offer therapy faster.

Achalasia

Achalasia is a rare neurogenic motility disorder of the esophagus, occurring in approximately 0.11 cases per 100,000 children. The combination of problems (aperistalsis, hypertensive lower esophageal sphincter (LES), and lack of receptive LES relaxation) results in patients having symptoms of progressive dysphagia, weight loss, and regurgitation. Treatment modalities have evolved over the past few decades from balloon dilation and botulinum toxin injection to laparoscopic Heller myotomy and endoscopic myotomy. Most data on achalasia management is extrapolated to children from adult experience. This article describes understanding of the pathogenesis and discusses newer therapeutic techniques as well as controversies in management.

Mutations in CRLF1 cause familial achalasia

We here report a family from Libya with three siblings suffering from early onset achalasia born to healthy parents. We analyzed roughly 5000 disease-associated genes by a next-generation sequencing (NGS) approach. In the analyzed sibling we identified two heterozygous variants in CRLF1 (cytokine receptor-like factor 1). Mutations in CRLF1 have been associated with autosomal recessive Crisponi or cold-induced sweating syndrome type 1 (CS/CISS1), which among other symptoms also manifests with early onset feeding difficulties. Segregation analysis revealed compound heterozygosity for all affected siblings, while the unaffected mother carried the c.713dupC (p.Pro239Alafs*91) and the unaffected father carried the c.178T>A (p.Cys60Ser) variant. The c.713dupC variant has already been reported in affected CS/CISS1 patients, the pathogenicity of the c.178T>A variant was unclear. As reported previously for pathogenic CRLF1 variants, cytokine receptor-like factor 1 protein secretion from cells transfected with the c.178T>A variant was severely impaired. From these results we conclude that one should consider a CRLF1-related disorder in early onset achalasia even if other CS/CISS1 related symptoms are missing.

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.

Etiology and Pathogenesis of Idiopathic Achalasia

This review examines the etiology and pathogenesis of idiopathic achalasia. This disease is clinically characterized by dysphagia of solids and liquids due to the presence of simultaneous or absent esophageal contractions and impaired or absent relaxation of the lower esophageal sphincter. It includes a review of (a) etiology and pathogenesis of this inflammatory process that damage the ganglion cells of the Auerbach plexus that is limited to the esophagus; (b) genetic abnormalities and polymorphisms associated with this disease that may help explain its heterogeneity expressed by the different motility abnormalities of its phenotypes as well as differences in its clinical progression. These different genetic abnormalities may be responsible for the slow progression of types I or II phenotypes; (c) indirect evidence of viruses present in these patients that may initiate its development; (d) the abnormalities of the muscle layer that may be responsible for the dilation of the body of the esophagus that ultimately causes the sigmoid-like esophagus in the very last phase of this disease. This progression to the end-stage phase tends to occur in about 5% of patients. And, (e) the chronic inflammatory abnormalities in the squamous mucosa that may be the cause of the dysplastic and neoplastic changes that may lead to squamous cell carcinoma whose incidence in this disease is increased. These mucosal abnormalities are usually present in patients with markedly dilated body of the esophagus and severe food stasis.

Esophagus-Related Symptoms in First-Degree Relatives of Patients with Achalasia: Is Screening Necessary?

BACKGROUND

Despite an increasing understanding of the pathophysiology of achalasia, the etiology of this esophageal motility disorder remains largely unknown. However, the occurrence of familial achalasia, its association with well-defined genetic syndromes, the candidate gene approach, and recent presentation of the first systematic genome-wide association study on achalasia suggest the involvement of genetic factors.

METHODS

In this study we analyzed the frequency with which symptoms associated with esophageal function (swallowing difficulties, regurgitations, retrosternal cramps/pain, heartburn) occur in first-degree relatives of patients with achalasia to determine if screening is useful and justified against the background of early diagnosis in a genetically predisposed population. The survey of data was carried out in 759 relatives of the 359 achalasia patients included in this study by means of structured interviews.

RESULTS

Swallowing difficulties as the principal symptom of achalasia were found to occur at least occasionally in 11.2% of first-degree relatives. In comparison with the prevalence of dysphagia in the general population of 7-10% up to 22%, as described in the literature, the frequency of swallowing difficulties does not seem to be increased in our population of relatives.

CONCLUSION

Screening measures do not appear to be justified in spite of the potential genetic background of achalasia.

New insights into the pathophysiology of achalasia and implications for future treatment

Idiopathic achalasia is an archetype esophageal motor disorder, causing significant impairment of eating ability and reducing quality of life. The pathophysiological underpinnings of this condition are loss of esophageal peristalsis and insufficient relaxation of the lower esophageal sphincter (LES). The clinical manifestations include dysphagia for both solids and liquids, regurgitation of esophageal contents, retrosternal chest pain, cough, aspiration, weight loss and heartburn. Even though idiopathic achalasia was first described more than 300 years ago, researchers are only now beginning to unravel its complex etiology and molecular pathology. The most recent findings indicate an autoimmune component, as suggested by the presence of circulating anti-myenteric plexus autoantibodies, and a genetic predisposition, as suggested by observed correlations with other well-defined genetic syndromes such as Allgrove syndrome and multiple endocrine neoplasia type 2 B syndrome. Viral agents (herpes, varicella zoster) have also been proposed as causative and promoting factors. Unfortunately, the therapeutic approaches available today do not resolve the causes of the disease, and only target the consequential changes to the involved tissues, such as destruction of the LES, rather than restoring or modifying the underlying pathology. New therapies should aim to stop the disease at early stages, thereby preventing the consequential changes from developing and inhibiting permanent damage. This review focuses on the known characteristics of idiopathic achalasia that will help promote understanding its pathogenesis and improve therapeutic management to positively impact the patient’s quality of life.

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.

Genetics of enteric neuropathies

Abnormal development or disturbed functioning of the enteric nervous system (ENS), the intrinsic innervation of the gastrointestinal tract, is associated with the development of neuropathic gastrointestinal motility disorders. Here, we review the underlying molecular basis of these disorders and hypothesize that many of them have a common defective biological mechanism. Genetic burden and environmental components affecting this common mechanism are ultimately responsible for disease severity and symptom heterogeneity. We believe that they act together as the fulcrum in a seesaw balanced with harmful and protective factors, and are responsible for a continuum of symptoms ranging from neuronal hyperplasia to absence of neurons.

Allele-specific transcriptional activity of the variable number of tandem repeats of the inducible nitric oxide synthase gene is associated with idiopathic achalasia

BACKGROUND

Polymorphisms of genes involved in the regulation of the immune response are risk factors for achalasia, but their contribution to disease pathogenesis is unknown. Nitric oxide is involved both in immune function and inhibitory neurotransmission.

OBJECTIVE

The objective of this article is to assess the association and the functional relevance of the CCTTT-inducible nitric oxide synthase (NOS2) gene promoter polymorphism in achalasia.

METHODS

Genomic DNA was isolated from 181 achalasia patients and 220 controls. Genotyping of the (CCTTT)n repeats was performed by PCR and capillary electrophoresis, and data analyzed by considering the frequency of the different alleles. HT29 cells were transfected with iNOS luciferase promoter-reporter plasmids containing different (CCTTT)n.

RESULTS

The alleles' distribution ranged from 7 to 18, with a peak frequency at 12 repeats. Analysis of the allele frequencies revealed that individuals carrying 10 and 13 CCTTT repeats were respectively less and more frequent in achalasia (OR 0.5, 95% CI 0.3-0.5 and OR 1.6, 95% CI 1-2.4, all p < 0.05). Long repeats were also significantly associated with an earlier onset of the disease (OR 1.69, 95% CI 1.13-2.53, p = 0.01). Transfection experiments revealed a similar allele-specific iNOS transcriptional activity.

CONCLUSION

The functional polymorphism (CCTTT) of NOS2 promoter is associated with achalasia, likely by an allele-specific modulation of nitric oxide production.

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.

Comprehensive epidemiological and genotype-phenotype analyses in a large European sample with idiopathic achalasia

BACKGROUND AND AIM

Although an eight-residue insertion in HLA-DQβ1 has been recently identified as a genetic risk factor for idiopathic achalasia, other risk factors are still unknown. In the present study, we carried out an epidemiological survey and a genotype-phenotype (G×P) analysis to gain further insights into the etiology of achalasia.

METHODS

We obtained medical data from 696 achalasia patients and 410 controls, as well as their first-degree relatives (2543 of patients and 1497 of controls). For the G×P analysis, we stratified the patients into HLA-DQβ1 insertion carriers and noncarriers.

RESULTS

Our data show that patients are more often affected by viral infections before achalasia onset (P<0.0001, most significantly for varicella zoster virus infections). In addition, allergic (P=0.0005) and autoimmune disorders (P=0.0007, most significantly for psoriasis and Sjögren's syndrome) represent comorbid disease conditions. First-degree relatives of patients also show higher prevalence rates of allergic disorders (P=0.0007) and psoriasis (P=0.016) compared with control relatives. Moreover, the G×P analysis reveals that achalasia is triggered by pregnancies in female HLA-DQβ1 insertion carriers (P=0.031).

CONCLUSION

Our data point to a role of viral infections in the development of achalasia. In addition, they provide evidence for a relationship between achalasia and allergic, as well as autoimmune, disorders. Furthermore, pregnancy seems to be a disease-triggering factor in female HLA-DQβ1 insertion carriers, which points to hormonal and/or immunosuppressive factors influencing disease development.

[Esophageal motility disorders]

Esophageal motility disorders are a group of diseases that result in swallowing dysfunction due to changes in neuromuscular structures, which coordinate esophageal function. Besides achalasia, which is the best defined functional disturbance of the esophagus, there are other motility disorders, namely hypercontractile (diffuse esophageal spasm, nutcracker or jackhammer esophagus, hypertensive lower esophageal sphincter) and hypocontractile disorders, whose origins and disease mechanisms are not yet well understood. The main symptoms are dysphagia and thoracic pain. Diagnosis is usually made by means of esophageal manometry, while endoscopy and barium swallow are essential to exclude inflammatory or neoplastic changes. The introduction of high resolution manometry (HRM) with up to 36 pressure points that are simultaneously measured on the esophageal catheter has changed diagnosis and assessment, and has led—with the Chicago Classification—to a new functional classification of esophageal motility disorders. In the following review, the most important motility disorders of the esophagus are introduced.

The Barrett-associated variants at GDF7 and TBX5 also increase esophageal adenocarcinoma risk

Barrett's esophagus (BE) and esophageal adenocarcinoma (EAC) represent two stages within the esophagitis-metaplasia-dysplasia-adenocarcinoma sequence. Previously genetic risk factors have been identified that confer risk to BE and EAC development. However, to which extent the genetic variants confer risk to different stages of the BE/EAC sequence remains mainly unknown. In this study we analyzed three most recently identified BE variants at the genes GDF7 (rs3072), TBX5 (rs2701108), and ALDH1A2 (rs3784262) separately in BE and EAC samples in order to determine their risk effects during BE/EAC sequence. Our data show that rs3072 at GDF7 and rs2701108 at TBX5 are also associated with EAC and conclude that both loci confer disease risk also at later stages of the BE/EAC sequence. In contrast, rs3784262 at ALDH1A2 was highly significantly associated with BE, but showed no association with EAC. Our data do not provide evidence that the ALDH1A2 locus confers equal risk in early and late stages of BE/EAC sequence.

The HLA-DQβ1 insertion is a strong achalasia risk factor and displays a geospatial north-south gradient among Europeans

Idiopathic achalasia is a severe motility disorder of the esophagus and is characterized by a failure of the lower esophageal sphincter to relax due to a loss of neurons in the myenteric plexus. Most recently, we identified an eight-amino-acid insertion in the cytoplasmic tail of HLA-DQβ1 as strong achalasia risk factor in a sample set from Central Europe, Italy and Spain. Here, we tested whether the HLA-DQβ1 insertion also confers achalasia risk in the Polish and Swedish population. We could replicate the initial findings and the insertion shows strong achalasia association in both samples (Poland P=1.84 × 10(-04), Sweden P=7.44 × 10(-05)). Combining all five European data sets - Central Europe, Italy, Spain, Poland and Sweden - the insertion is achalasia associated with Pcombined=1.67 × 10(-35). In addition, we observe that the frequency of the insertion shows a geospatial north-south gradient. The insertion is less common in northern (around 6-7% in patients and 2% in controls from Sweden and Poland) compared with southern Europeans (~16% in patients and 8% in controls from Italy) and shows a stronger attributable risk in the southern European population. Our study provides evidence that the prevalence of achalasia may differ between populations.

Achalasia: new perspectives on an old disease

Achalasia is defined by esophageal outflow obstruction from abnormal relaxation of the lower esophageal sphincter (LES) due to deranged inhibitory control. In genetically predisposed individuals, an autoimmune response to an unknown inciting agent, perhaps a viral infection, results in inflammation and sometimes loss of myenteric plexus ganglia and neurons. The net result is varying degrees of inhibitory dysfunction, at times associated with imbalanced and exaggerated excitatory function, with manometrically distinct achalasia phenotypes on high resolution manometry. There is new evidence in the current issue of this Journal suggesting that type 1 achalasia, with esophageal outflow obstruction and absent esophageal body contractility, is an end-stage phenotype from progression of type 2 achalasia, which is characterized by panesophageal compartmentalization of pressure in the untreated patient, and partial recovery of peristalsis after treatment. Esophageal outflow obstruction with premature peristalsis (type 3 achalasia) or intact peristalsis may result from plexitis in the myenteric plexus but can also be encountered in other settings including chronic opioid medication usage and structural processes at the esophagogastric junction and distally. In most instances when idiopathic esophageal outflow obstruction is confirmed, some form of pharmacologic manipulation or disruption of the LES provides durable symptom relief. This review will focus on current understanding of pathophysiology, diagnosis, and principles of management of achalasia in light of emerging literature on the topic.

Genome-Wide Association Study of Late-Onset Myasthenia Gravis: Confirmation of TNFRSF11A and Identification of ZBTB10 and Three Distinct HLA Associations

To investigate the genetics of late-onset myasthenia gravis (LOMG), we conducted a genome-wide association study imputation of>6 million single nucleotide polymorphisms (SNPs) in 532 LOMG cases (anti-acetylcholine receptor [AChR] antibody positive; onset age≥50 years) and 2,128 controls matched for sex and population substructure. The data confirm reported TNFRSF11A associations (rs4574025, P = 3.9 × 10^-7, odds ratio [OR] 1.42) and identify a novel candidate gene, ZBTB10, achieving genome-wide significance (rs6998967, P = 8.9 × 10^-10, OR 0.53). Several other SNPs showed suggestive significance including rs2476601 (P = 6.5 × 10^-6, OR 1.62) encoding the PTPN22 R620W variant noted in early-onset myasthenia gravis (EOMG) and other autoimmune diseases. In contrast, EOMG-associated SNPs in TNIP1 showed no association in LOMG, nor did other loci suggested for EOMG. Many SNPs within the major histocompatibility complex (MHC) region showed strong associations in LOMG, but with smaller effect sizes than in EOMG (highest OR ~2 versus ~6 in EOMG). Moreover, the strongest associations were in opposite directions from EOMG, including an OR of 0.54 for DQA1*05:01 in LOMG (P = 5.9 × 10^-12) versus 2.82 in EOMG (P = 3.86 × 10^-45). Association and conditioning studies for the MHC region showed three distinct and largely independent association peaks for LOMG corresponding to (a) MHC class II (highest attenuation when conditioning on DQA1), (b) HLA-A and (c) MHC class III SNPs. Conditioning studies of human leukocyte antigen (HLA) amino acid residues also suggest potential functional correlates. Together, these findings emphasize the value of subgrouping myasthenia gravis patients for clinical and basic investigations and imply distinct predisposing mechanisms in LOMG.

The genetics of human autoimmune disease: A perspective on progress in the field and future directions

Progress in defining the genetics of autoimmune disease has been dramatically enhanced by large scale genetic studies. Genome-wide approaches, examining hundreds or for some diseases thousands of cases and controls, have been implemented using high throughput genotyping and appropriate algorithms to provide a wealth of data over the last decade. These studies have identified hundreds of non-HLA loci as well as further defining HLA variations that predispose to different autoimmune diseases. These studies to identify genetic risk loci are also complemented by progress in gene expression studies including definition of expression quantitative trait loci (eQTL), various alterations in chromatin structure including histone marks, DNase I sensitivity, repressed chromatin regions as well as transcript factor binding sites. Integration of this information can partially explain why particular variations can alter proclivity to autoimmune phenotypes. Despite our incomplete knowledge base with only partial definition of hereditary factors and possible functional connections, this progress has and will continue to facilitate a better understanding of critical pathways and critical changes in immunoregulation. Advances in defining and understanding functional variants potentially can lead to both novel therapeutics and personalized medicine in which therapeutic approaches are chosen based on particular molecular phenotypes and genomic alterations.

[Diagnostics and therapy of achalasia]

The low incidence (1:100,000) makes primary idiopathic achalasia a problem of special importance. Patients often have a long medical history of suffering before the diagnosis is established and adequate therapy provided. Surgeons who perform antireflux surgery must be certain of detecting achalasia patients within their collective of gastroesophageal reflux disease (GERD) patients to avoid contraindicated fundoplication. The current gold standard for establishing the diagnosis of achalasia is manometry. Especially in early stages, symptom evaluation, endoscopy and barium swallow lack adequate sensitivity. High-resolution manometry (HRM) is increasingly used and allows characterization of different achalasia types (i.e. type I classical achalasia, type II panesophageal pressurization and type III spasmodic achalasia) and differentiation from other motility disorders (e.g. distal esophageal spasm, jackhammer esophagus and nutcracker esophagus). For patients over 45 years of age additional endoscopic ultrasound and computed tomography are recommended to exclude pseudoachalasia. A curative treatment restoring normal esophageal function does not exist; however, there are good options for symptom control. Therapy aims are abolishment of dysphagia, improvement of esophageal clearance, prevention of reflux and abolishment of chest pain. The current standard treatment is cardiomyotomy, which was first described 100 years ago by the German surgeon Ernst Heller and has been shown to be clearly superior when compared to endoscopic treatment (e.g. botox injection and balloon dilatation). Heller's myotomy procedure is preferentially performed via the laparoscopic route and combined with partial fundoplication. Currently, an alternative to performing Heller's myotomy via the endoscopic route is under intensive investigation in several centers worldwide. The peroral endoscopic myotomy (POEM) procedure has shown very promising initial results and warrants further clinical evaluation.

Widespread non-additive and interaction effects within HLA loci modulate the risk of autoimmune diseases

Human leukocyte antigen (HLA) genes confer strong risk for autoimmune diseases on a log-additive scale. Here we speculated that differences in autoantigen binding repertoires between a heterozygote’s two expressed HLA variants may result in additional non-additive risk effects. We tested non-additive disease contributions of classical HLA alleles in patients and matched controls for five common autoimmune diseases: rheumatoid arthritis (RA, N_cases=5,337), type 1 diabetes (T1D, N_cases=5,567), psoriasis vulgaris (N_cases=3,089), idiopathic achalasia (N_cases=727), and celiac disease (N_cases=11,115). In four out of five diseases, we observed highly significant non-additive dominance effects (RA: P=2.5×10¹²; T1D: P=2.4×10⁻¹⁰; psoriasis: P=5.9×10⁻⁶; celiac disease: P=1.2×10⁻⁸⁷). In three of these diseases, the dominance effects were explained by interactions between specific classical HLA alleles (RA: P=1.8×10⁻³; T1D: P=8.6×10²⁷; celiac disease: P=6.0×10⁻¹⁰⁰). These interactions generally increased disease risk and explained moderate but significant fractions of phenotypic variance (RA: 1.4%, T1D: 4.0%, and celiac disease: 4.1%, beyond a simple additive model).

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 with megaesophagus and tracheal compression in a young patient: A case report

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This report emphasizes that physicians should be alert and consider airway obstruction and signs of dyspnea as severe and threatening symptoms in extensive cases of achalasia with megaesophagus.

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Early surgical treatment provides a therapeutic option to obviate the occurrence of acute respiratory distress and consecutive complications.

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In particular, difficulties in intubation prior to surgery must be considered. Due to potential tracheomalacia, the status of “bull frog neck” in achalasia, including severe tracheal compression caused by megaesophagus with concomitant cervical swelling, may also lead to extubation problems and deserves special care in the postoperative period.

Introduction

Achalasia is one of the most common causes of dysphagia. Typical symptoms include difficulties in controlling the swallowing process, regurgitation, weight loss, and chest pain. A megaesophagus rarely causes tracheal compression with consecutive acute dyspnea or similar respiratory symptoms.

Presentation of case

A 23-year-old male patient presented with difficulties in swallowing, a consecutive massive weight loss over the past three years, and minor respiratory ailments. Further diagnostics revealed a megaesophagus caused by achalasia leading to a severe compression of the trachea.

A laparoscopic Heller myotomy with anterior semi-fundoplication 180° according to Dor was performed.

Discussion

Acute dyspnea and similar respiratory symptoms are rarely observed in patients with achalasia, especially in young patients. Early diagnosis and timely, proper treatment are the hallmarks of restoring esophageal and tracheobronchial function and of successful prevention of severe long-lasting complications of the disease. When not treated properly, the disease may have progressed rapidly, leading to distinct respiratory symptoms such as stridor and acute dyspnea

Conclusion

This report emphasizes that physicians should be alert and consider airway obstruction and signs of dyspnea as severe and threatening symptoms in extensive cases of achalasia with megaesophagus. Early surgical treatment provides a therapeutic option to obviate the occurrence of acute respiratory distress and consecutive complications. In particular, difficulties in intubation prior to surgery must be considered.

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.

Variation at HLA-DRB1 is associated with resistance to enteric fever

Enteric fever affects more than 25 million people annually and results from systemic infection with Salmonella enterica serovar Typhi or Paratyphi pathovars A, B or C(1). We conducted a genome-wide association study of 432 individuals with blood culture-confirmed enteric fever and 2,011 controls from Vietnam. We observed strong association at rs7765379 (odds ratio (OR) for the minor allele = 0.18, P = 4.5 × 10(-10)), a marker mapping to the HLA class II region, in proximity to HLA-DQB1 and HLA-DRB1. We replicated this association in 595 enteric fever cases and 386 controls from Nepal and also in a second independent collection of 151 cases and 668 controls from Vietnam. Imputation-based fine-mapping across the extended MHC region showed that the classical HLA-DRB1*04:05 allele (OR = 0.14, P = 2.60 × 10(-11)) could entirely explain the association at rs7765379, thus implicating HLA-DRB1 as a major contributor to resistance against enteric fever, presumably through antigen presentation.