Autoaggressive inflammation of the myenteric plexus resulting in intestinal pseudoobstruction

Paraneoplastic vs. non-paraneoplastic anti-Hu associated dysmotility: a case series and literature review

OBJECTIVES

This work aimed to report the demographic and clinical characteristics of two new cases with non-paraneoplastic anti-Hu-associated gut motility impairment, and perform a thorough revision covering anti-Hu-associated paraneoplastic (PGID) and non-paraneoplastic (nPGID) gastrointestinal dysmotility.

BACKGROUND

Several case series have clearly established a relationship between certain type of cancers, the development of circulating anti-Hu antibodies, and the concomitant usually severe gastrointestinal dysmotility; in contrast, a few studies focused on anti-Hu-associated nPGID.

METHODS

We searched for studies regarding anti-Hu-associated gastrointestinal manifestations and extracted data concerning clinical characteristics of patients, including specific demographic, oncological, neurological, gastrointestinal, histological, and treatment response features.

RESULTS

Forty-nine articles with a total of 59 cases of anti-Hu-associated gastrointestinal dysmotility were analyzed. The patients' age at symptom onset significantly differed between PGID and nPGID (median 61 vs 31 years, p < 0.001). Most cancers (95%) in PGID were detected within 24 months from the beginning of gastrointestinal symptoms. The impairment of gastrointestinal motility was generalized (i.e., involving the whole gut) in 59.3% of patients, with no significant differences between PGID vs nPGID group. nPGID patients showed a better response to immunomodulatory/immunosuppressive treatment and a longer life expectancy.

CONCLUSIONS

Anti-Hu-associated gastrointestinal dysmotility covers a wide clinical spectrum. Patients with otherwise unexplained gastrointestinal dysmotility, especially when associated with other neurological symptoms, should be tested for anti-Hu antibodies regardless age of onset and disease duration. Compared to PGID, nPGID occurs in younger patients with a long duration of disease.

Delayed appearance of mature ganglia in an infant with an atypical presentation of total colonic and small bowel aganglionosis: a case report

Background

Total colonic and small bowel aganglionosis (TCSA) occurs in less than 1% of all Hirschsprung’s disease patients. Currently, the mainstay of treatment is surgery. However, in patients with TCSA, functional outcomes are often poor. A characteristic transition zone in TCSA can be difficult to identify which may complicate surgery and may often require multiple operations.

Case presentation

We present the case of a male infant who was diagnosed with biopsy-proven total colonic aganglionosis with extensive small bowel involvement as a neonate. The patient was diverted at one month of age based on leveling biopsies at 10 cm from the Ligament of Treitz. At 7 months of age, during stoma revision for a prolapsed stoma, intra-operative peristalsis was observed in nearly the entire length of the previously aganglionic bowel, and subsequent biopsies demonstrated the appearance of mature ganglion cells in a previously aganglionic segment.

Conclusions

TCSA remains a major challenge for pediatric surgeons. Our case introduces new controversy to our understanding of aganglionosis. Our observations warrant further research into the possibility of post-natal ganglion maturation and encourage surgeons to consider a more conservative surgical approach.

Enteric Murine Ganglionitis Induced by Autoimmune CD8 T Cells Mimics Human Gastrointestinal Dysmotility

Inflammatory bowel diseases frequently cause gastrointestinal dysmotility, suggesting that they may also affect the enteric nervous system. So far, the precise mechanisms that lead to gastrointestinal dysmotility in inflammatory bowel diseases have not been elucidated. To determine the effect of CD8 T cells on gastrointestinal motility, transgenic mice expressing ovalbumin on enteric neurons were generated. In these mice, adoptive transfer of ovalbumin-specific OT-I CD8 T cells induced severe enteric ganglionitis. CD8 T cells homed to submucosal and myenteric plexus neurons, 60% of which were lost, clinically resulting in severely impaired gastrointestinal transition. Anti-interferon-γ treatment rescued neurons by preventing their up-regulation of major histocompatibility complex class I antigen, thus preserving gut motility. These preclinical murine data translated well into human gastrointestinal dysmotility. In a series of 30 colonic biopsy specimens from patients with gastrointestinal dysmotility, CD8 T cell-mediated ganglionitis was detected that was followed by severe loss of enteric neurons (74.8%). Together, the preclinical and clinical data support the concept that autoimmune CD8 T cells play an important pathogenetic role in gastrointestinal dysmotility and may destroy enteric neurons.

Antineuronal Nuclear Autoantibody Type 1/Anti-Hu-Associated Opsoclonus Myoclonus and Epilepsia Partialis Continua: Case Report and Literature Review

BACKGROUND

Opsoclonus-myoclonus syndrome is a rare clinical condition that has been associated with neuroblastoma. There are few reported examples of ANNA-1/anti-Hu antibodies in children with neuroblastoma and opsoclonus-myoclonus, all in children aged less than three years of age.

METHODS

We describe the new onset of focal seizures without alteration of consciousness and opsoclonus-myoclonus in an 11-year-old girl with ANNA-1/anti-Hu positivity and a paraspinal ganglioneuroblastoma. A systematic review of the literature of children with ANNA-1/anti-Hu positivity and malignancy was also performed.

RESULTS

Fourteen patients were identified, eight of whom had opsoclonus-myoclonus. Although epilepsia partialis continua has been described in association with several neuronal autoantibodies, association with ANNA-1/anti-Hu has not been reported.

CONCLUSIONS

We describe epilepsia partialis continua in a child with ANNA-1/anti-Hu antibodies and neuroblastoma. Testing for antineuronal antibodies should be considered in children presenting with either opsoclonus-myoclonus or epilepsia partialis continua.

New perspectives in the diagnosis and management of enteric neuropathies

Chronic disturbances of gastrointestinal function encompass a wide spectrum of clinical disorders that range from common conditions with mild-to-moderate symptoms to rare diseases characterized by a severe impairment of digestive function, including chronic pain, vomiting, bloating and severe constipation. Patients at the clinically severe end of the spectrum can have profound changes in gut transit and motility. In a subset of these patients, histopathological analyses have revealed abnormalities of the gut innervation, including the enteric nervous system, termed enteric neuropathies. This Review discusses advances in the diagnosis and management of the main clinical entities--achalasia, gastroparesis, intestinal pseudo-obstruction and chronic constipation--that result from enteric neuropathies, including both primary and secondary forms. We focus on the various evident neuropathologies (degenerative and inflammatory) of these disorders and, where possible, present the specific implications of histological diagnosis to contemporary treatment. This knowledge could enable the future development of novel targeted therapeutic approaches.

Pathology of Intestinal Motor Disorders in Children

Varied intestinal neuromuscular pathologies are responsible for Hirschsprung disease and other forms of chronic pseudo-obstruction that are encountered in pediatrics. Pathologically distinct subtypes discussed in this review include aganglionosis, hypoganglionosis, neuronal intranuclear inclusion disease, ganglionitis, degenerative neuropathy, diffuse ganglioneuromatosis, neuronal dysplasia, malformations of the muscularis propria, degenerative leiomyopathy, leiomyositis, and mitochondriopathies. Emphasis is given to the histopathologic features that distinguish these conditions and their differential diagnoses.

Paraneoplastic gastro-intestinal anti-Hu syndrome in neuroblastoma

The anti-Hu syndrome is a well-known paraneoplastic syndrome and may be rarely seen in patients with neuroblastoma. However, it is relatively unknown that anti-Hu antibodies can cause gastro-intestinal signs and symptoms. We report on a child with neuroblastoma who presented with gastro-intestinal disturbances as a result of the anti-Hu syndrome and summaries two similar case reports reported in literature. Neuroblastoma patients with gastro-intestinal disturbances, ranging from constipation to a paralytic ileus, might suffer from the gastro-intestinal anti-Hu syndrome. The causative antibodies can be determined to diagnose or exclude this syndrome, and successful treatment is possible.

The role of humoral autoimmunity in gastrointestinal neuromuscular diseases

Dysfunction of the gastrointestinal neuromuscular apparatus (including interstitial cells of Cajal) is presumed to underlie a heterogeneous group of disorders collectively termed gastrointestinal neuromuscular diseases (GINMDs). There is increasing experimental and clinical evidence that some GINMDs are immune-mediated, with cell-mediated dysfunction relatively well studied. Humoral (antibody)-mediated autoimmunity is associated with several well-established acquired neuromuscular diseases and is now implicated in an increasing number of less well-characterised disorders, particularly of the central nervous system. The role of autoimmunity in GINMDs has been less studied. Whilst most work has focused on the presence of antibodies directed to nuclear antigens, particularly in the context of secondary disorders such as paraneoplastic intestinal pseudo-obstruction, the possibility that 'functional' anti-neuronal antibodies directed to membrane-bound ion channels may cause disease (channelopathy) is now also being realised. The evidence for humoral autoimmunity as an etiologic factor in primary (idiopathic) and secondary GINMDs is systematically presented using the original paradigms previously applied to established autoimmune neuromuscular disorders. The presence of anti-enteric neuronal antibodies, although repeatedly demonstrated, still requires the identification of specific neuronal autoantigens and validated evidence of pathogenicity.

Enteric autoantibodies and gut motility disorders

Increasing evidence suggests that a subset of gastrointestinal motility disorders is associated with the presence of circulating antibodies. These antibodies are directed against various molecular targets, the best known being anti-neuronal nuclear antibody (ANNA-1 or anti-Hu) associated with paraneoplastic motility disorders. There is also evidence that the presence of distinct autoantibody profiles is associated with non-paraneoplastic motility disorders. This review focuses on the types of antibodies associated with gastrointestinal motility disorders and the significance of these antibodies. Algorithms are suggested for the work-up and treatment of patients with circulating antibodies associated with gastrointestinal motility disorders.

[Hypoganglionosis as a cause of chronic constipation]

Hypoganglionosis comprises 3-5% of gastrointestinal innervation defects which are connected to therapy-resistant chronic constipation in children and adults. Similar to Hirschsprung's disease, hypoganglionosis may be complicated by megacolon formation and must be considered in the differential diagnosis. Three main subtypes may be distinguished: congenital hypoplastic hypoganglionosis occurs predominantly in Hirschsprung's disease proximal to the aganglionic segment and consists of small paucicellular ganglia with increased interganglionic distances. Oligoneuronal dysganglionic hypoganglionosis manifests in childhood. Initially, myenteric ganglia are of normal size and have normal interganglionic spacing and normal neuronal content. However, nerve cells are hypoplastic and ganglia undergo progressive nerve cell loss. This type of hypoganglionosis may progress into atrophic hypoganglionosis, which shows a morphology similar to hypoplastic hypoganglionosis. All subtypes of hypoganglionosis result in decreased acetylcholinesterase activity in the nerve fiber network of the muscularis propria. The pathogenesis of hypoganglionosis is still poorly understood. In Hirschsprung associated hypoganglionosis, mutations in the RET and GDNF-genes have been found. Despite a heterozygote GDNF+/- animal model for hypoganglionosis, no GDNF mutations have so far been demonstrated in human Hirschsprung independent, isolated hypoganglionosis.

Therapeutic total plasma exchange in a child with neuroblastoma-related anti-Hu syndrome

A 5-year-old boy underwent total plasma exchange to remove anti-neuronal anti-Hu autoantibodies as a complication of neuroblastoma, leading to autonomic bowel dysfunction. Total plasma exchange (TPE) resulted eventually in a reduction of autoantibody levels, but, more importantly, led to improvement of bowel function. TPE proved to be a safe and effective treatment option in neuroblastoma-related anti-Hu syndrome in a child.

The pathogenesis of gastrointestinal bacterial overgrowth

The normal indigenous intestinal microflora consists of about 10(15) bacteria that under physiological conditions reside mainly in the lower gastrointestinal tract. Bacterial overgrowth implies abnormal bacterial colonization of the upper gut, resulting from failure of specific defense mechanisms restricting colonization under physiological conditions. At present two types of bacterial overgrowth with defined pathogenesis can be distinguished: (1) gastric overgrowth with upper respiratory tract microflora resulting from selective failure of the gastric acid barrier, and (2) gastrointestinal overgrowth with Gram-negative bacilli (enteric bacteria) resulting from failure of intestinal clearance. Helicobacter pylori-induced gastritis of the oxyntic mucosa is the main cause of acquired failure of the gastric acid barrier, which is common among the healthy elderly. Intestinal clearance may fail as the result of impaired intestinal peristalsis or anatomical abnormalities that alter luminal flow. Impaired peristalsis is associated with conditions interfering with intestinal neuromuscular function including myopathic, neuropathic, autoimmune, infectious, inflammatory, metabolic, endocrine, and neoplastic diseases. Anatomical abnormalities are mainly the result of gastrointestinal surgery, intestinal diverticula or fistula. Combined failure of intestinal clearance and the gastric acid barrier results in more severe colonization with Gram-negative bacilli. Gram-negative bacilli are uncommon in the upper gut of otherwise healthy individuals with gastric hypochlorhydria, being acquired (H. pylori) or drug-induced. Significant bacterial overgrowth with Gram-negative bacilli is a rational in the search for an explanation to optimize clinical management. The clinical significance of colonization with upper respiratory tract microflora remains unclear. Translocation of live bacteria, their metabolic products, or antigens from a small bowel colonized by Gram-negative bacilli play a role in the pathogenesis of spontaneous bacterial peritonitis in hepatic disease and in certain types of sepsis, indicating that further studies can point to new patient populations with potential benefit from medical treatment.

Obstipation as a paraneoplastic presentation of small cell lung cancer: case report and literature review

Paraneoplastic symptoms caused by abnormal gastrointestinal motility may be the initial manifestation of small cell lung cancer (SCLC). We report a case of a 63-year-old woman who presented with progressive constipation culminating in obstipation, and associated symptoms of more widespread dysmotility. A paraneoplastic syndrome was suspected. The only abnormality on chest computed tomography was a minimally enlarged paratracheal lymph node. Positron emission tomography demonstrated increased activity in the lymph node. The antinuclear neuronal antibody titer was elevated. Bronchoscopy with transtracheal biopsy confirmed the diagnosis of SCLC. One year after diagnosis, the patient had progressive symptoms of intestinal obstruction, and ultimately feculent vomiting. On abdominal radiography, colonic sitz markers ingested a year earlier were in virtually the same positions as after ingestion. Palliative colectomy with ileostomy was performed. The myenteric plexus in the terminal ileum and colon showed infiltration by a mixture of B-cell and T-cell lymphocytes and plasma cells, and no gross neuronal abnormalities. We review the clinical and pathologic features, clinical course, and management of paraneoplastic pseudoobstruction.

Human enteric neuropathies: morphology and molecular pathology

The aim of this study is to review current understanding of the molecular and morphological pathology of the enteric neuropathies affecting motor function of the human gastrointestinal tract and to evaluate the described pathological entities in the literature to assess whether a new nosology may be proposed. The authors used PUBMED and MEDLINE searches to explore the literature pertinent to the molecular events and pathology of gastrointestinal motility disorders including achalasia, gastroparesis, intestinal pseudo-obstruction, colonic inertia and megacolon in order to characterize the disorders attributable to enteric gut neuropathies. This scholarly review has shown that the pathological features are not readily associated with clinical features, making it difficult for a patient to be classified into any specific category. Individual patients may manifest more than one of the morphological and molecular abnormalities that include: aganglionosis, neuronal intranuclear inclusions and apoptosis, neural degeneration, intestinal neuronal dysplasia, neuronal hyperplasia and ganglioneuromas, mitochondrial dysfunction (syndromic and non-syndromic), inflammatory neuropathies (caused by cellular or humoral immune mechanisms), neurotransmitter diseases and interstitial cell pathology. The pathology of enteric neuropathies requires further study before an effective nosology can be proposed. Carefully studied individual cases and small series provide the basic framework for standardizing the collection and histological evaluation of tissue obtained from such patients. Combined clinical and histopathological studies may facilitate the translation of basic science to the clinical management of patients with enteric neuropathies.

Paraneoplastic syndromes in ganglioneuroblastoma: contrasting symptoms of constipation and diarrhoea

A paraneoplastic syndrome is occasionally the first clinical symptom seen with tumours. We report on two children who initially presented with paraneoplastic syndromes due to ganglioneuroblastomas: the first with severe watery diarrhoea caused by a ganglioneuroma producing vasoactive intestinal peptide, the second with non-treatable constipation, caused by ganglioneuroma-produced anti-neuronal nuclear antibodies.

CONCLUSION

Either severe diarrhoea or chronic constipation may represent rare paraneoplastic syndromes in ganglioneuroblastomas.

Anti-HuD-induced neuronal apoptosis underlying paraneoplastic gut dysmotility

BACKGROUND & AIMS

The role of autoimmunity underlying paraneoplastic gut dysmotility remains unsettled. Because anti-Hu antibodies may impair enteric neuronal function, we tested whether anti-HuD-positive sera from patients with paraneoplastic gut dysmotility or commercial anti-HuD antibodies activated the apoptotic cascade in a neuroblastoma cell line and cultured myenteric neurons.

METHODS

Anti-HuD antibodies from patients with severe paraneoplastic gut dysmotility were characterized by immunofluorescence and immunoblot. SH-Sy5Y neuroblasts and cultured myenteric neurons were exposed to sera containing anti-HuD antibodies or 2 commercial anti-HuD antibodies. Cells were processed for terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling (TUNEL) technique to evaluate apoptosis. Immunofluorescence was used to identify activated caspase-3 and apaf-1, along with microtubule-associated protein 2.

RESULTS

In SH-Sy5Y cells, the percentage of TUNEL-positive nuclei observed after exposure to anti-HuD-positive sera (32% +/- 7%) or anti-HuD antibodies (23% +/- 2%) was significantly greater than that of control sera or fetal calf serum (P < 0.001). The time-course analysis showed a significantly greater number of apoptotic neuroblastoma cells evoked by the 2 commercial anti-HuD antibodies at 24, 48, and 72 hours versus controls. The number of TUNEL-positive myenteric neurons exposed to anti-HuD antibodies (60% +/- 14%) was significantly greater than that of fetal calf serum (7% +/- 2%; P < 0.001). Apaf-1 and caspase-3 immunolabeling showed intense cytoplasmic staining in a significantly greater proportion of cells exposed to anti-HuD-positive sera or to commercial anti-HuD antibodies compared with controls.

CONCLUSIONS

Anti-HuD antibodies evoked neuronal apoptosis that may contribute to enteric nervous system impairment underlying paraneoplastic gut dysmotility. Apaf-1 activation suggests participation of a mitochondria-dependent apoptotic pathway.

Clinical and morphofunctional features of idiopathic myenteric ganglionitis underlying severe intestinal motor dysfunction: a study of three cases

Ganglionitis, i.e., the inflammatory neuropathy characterized by a marked lymphoplasmacellular infiltrate in the myenteric plexus, may underlie a variety of paraneoplastic, infectious, or neurological disorders, although occasional cases are idiopathic in origin. We report clinical, manometric, morphofunctional, and immunological features of three cases of idiopathic ganglionitis. All patients had megacolon and underwent surgery for repeated episodes of intestinal subocclusion. Esophageal, GI, and colonic manometry performed in one patient showed dysmotility of the whole gut. Histological examination of colonic and ileum specimens identified a prominent lymphoplasmacellular infiltrate within the myenteric plexus along with a marked decrease of a wide array of neuronal peptides/transmitters. In one patient, tissue analysis revealed progressive neuronal changes up to marked myenteric neuron damage. The inflammatory infiltrate in all patients comprised CD4+ and CD8+ T lymphocytes. Abundance of both subclasses of lymphocytes suggests that immune-mediated mechanisms were responsible for neuronal degeneration. In one patient, systemic steroid therapy brought a significant clinical improvement. The immunosuppressive approach deserves further investigation in patients with severe gut motor abnormalities attributable to idiopathic myenteric ganglionitis.