Sympathetic Denervation Alters the Inflammatory Response of Resident Muscularis Macrophages upon Surgical Trauma and Ameliorates Postoperative Ileus in Mice.

Interactions between the peripheral nervous system and resident macrophages (MMs) modulate intestinal homeostatic functions. Activation of ß2-adrenergic receptors on MMs has been shown to reduce bacterial challenges. These MMs are also crucial for the development of bowel inflammation in postoperative ileus (POI), an iatrogenic, noninfectious inflammation-based motility disorder. However, the role of the sympathetic nervous system (SNS) in the immune modulation of these MMs during POI or other noninfectious diseases is largely unknown. By employing 6-OHDA-induced denervation, we investigated the changes in the muscularis externa by RNA-seq, quantitative PCR, and flow cytometry. Further, we performed transcriptional phenotyping of sorted CX3CR1+ MMs and ex vivo LPS/M-CSF stimulation on these MMs. By combining denervation with a mouse POI model, we explored distinct changes on CX3CR1+ MMs as well as in the muscularis externa and their functional outcome during POI. Our results identify SNS as an important mediator in noninfectious postoperative inflammation. Upon denervation, MMs anti-inflammatory genes were reduced, and the muscularis externa profile is shaped toward a proinflammatory status. Further, denervation reduced MMs anti-inflammatory genes also in the early phase of POI. Finally, reduced leukocyte infiltration into the muscularis led to a quicker recovery of bowel motility in the late phase of POI.

Clinical and Histopathological Spectrum of Adult Gastrointestinal Inflammatory Neuropathy.

Gastrointestinal inflammatory neuropathy, namely, eosinophilic myenteric ganglioneuronitis (EMG) and lymphocytic ganglioneuronitis (LG), is a form of chronic intestinal pseudo-obstruction and results from the infiltration of the myenteric plexus by eosinophils and lymphocytes, respectively. The literature related to the clinicopathological features of adult inflammatory neuropathy is scarce. We aim to elucidate the clinical and histological details of 7 cases of inflammatory neuropathy (EMG, n = 4, and LG, n = 3) and compare the features of EMG and LG retrospectively. There was no difference between these two entities in terms of clinical, hematological, or biochemical parameters. Histologically, almost all cases (n = 6/7) showed accompanying elements of ganglion cell vacuolization, mesenchymopathy, and partial/complete desmosis in addition to the disease-defining pathology. Besides, all cases of EMG showed infiltration of the inner circular muscle of muscularis propria by eosinophils. Two cases of LG showed additional muscular pathology pertaining to the muscularis propria. Inflammatory infiltration of the myenteric plexus is pathognomonic for the diagnosis of gastrointestinal inflammatory neuropathy although additional features in the form of ganglion cell vacuolization, reduction in the number of ganglia, desmosis, mesenchymopathy, and inflammation of the muscularis propria (eosinophils in EMG) can be seen. The pathologists need proper awareness along with judicious use of special and immunostains for clinching the diagnosis.

Postoperative ileus-An ongoing conundrum.

BACKGROUND: Postoperative ileus is common and is a major clinical problem. It has been widely studied in patients and in experimental models in laboratory animals. A wide variety of treatments have been tested to prevent or modify the course of this disorder. PURPOSE: This review draws together information on animal studies of ileus with studies on human patients. It summarizes some of the conceptual advances made in understanding the mechanisms that underlie paralytic ileus. The treatments that have been tested in human subjects (both pharmacological and non-pharmacological) and their efficacy are summarized and graded consistent with current clinical guidelines. The review is not intended to provide a comprehensive overview of ileus, but rather a general understanding of the major clinical problems associated with it, how animal models have been useful to elucidate key mechanisms and, finally, some perspectives from both scientists and clinicians as to how we may move forward with this debilitating yet common condition.

Neurological autoimmune disorders with prominent gastrointestinal manifestations: A review of presentation, evaluation, and treatment.

BACKGROUND: The identification of autoantibodies directed against neuronal antigens has led to the recognition of a wide spectrum of neurological autoimmune disorders (NAD). With timely recognition and treatment, many patients with NAD see rapid improvement. Symptoms associated with NAD can be diverse and are determined by the regions of the nervous system affected. In addition to neurological symptoms, a number of these disorders present with prominent gastrointestinal (GI) manifestations such as nausea, diarrhea, weight loss, and gastroparesis prompting an initial evaluation by gastroenterologists. PURPOSE: This review provides a general overview of autoantibodies within the nervous system, focusing on three scenarios in which nervous system autoimmunity may initially present with gut symptoms. A general approach to evaluation and treatment, including antibody testing, will be reviewed.

Anti-ganglionic AChR antibodies in Japanese patients with motility disorders.

BACKGROUND: The existence of several autoantibodies suggests an autoimmune basis for gastrointestinal (GI) dysmotility. Whether GI motility disorders are features of autoimmune autonomic ganglionopathy (AAG) or are related to circulating anti-ganglionic acetylcholine receptor (gAChR) antibodies (Abs) is not known. The aim of this study was to determine the associations between autonomic dysfunction, anti-gAChR Abs, and clinical features in patients with GI motility disorders including achalasia and chronic intestinal pseudo-obstruction (CIPO). METHODS: First study: retrospective cohort study and laboratory investigation. Samples from 123 patients with seropositive AAG were obtained between 2012 and 2017. Second study: prospective study. Samples from 28 patients with achalasia and 14 patients with CIPO were obtained between 2014 and 2016, and 2013 and 2017, respectively. In the first study, we analyzed clinical profiles of seropositive AAG patients. In the second study, we compared clinical profiles, autonomic symptoms, and results of antibody screening between seropositive, seronegative achalasia, and CIPO groups. RESULTS: In the first study, we identified 10 patients (8.1%) who presented with achalasia, or gastroparesis, or paralytic ileus. In the second study, we detected anti-gAChR Abs in 21.4% of the achalasia patients, and in 50.0% of the CIPO patients. Although patients with achalasia and CIPO demonstrated widespread autonomic dysfunction, bladder dysfunction was observed in the seropositive patients with CIPO as a prominent clinical characteristic of dysautonomia. CONCLUSIONS: These results demonstrate a significant prevalence of anti-gAChR antibodies in patients with achalasia and CIPO. Anti-gAChR Abs might mediate autonomic dysfunction, contributing to autoimmune mechanisms underlying these GI motility disorders.

Abdominal surgery induced gastric ileus and activation of M1-like macrophages in the gastric myenteric plexus: prevention by central vagal activation in rats.

Inflammation plays a role in abdominal surgery (AS)-induced intestinal ileus that is alleviated by electrical vagal stimulation. Intracisternal injection of RX-77368, the stable thyrotropin-releasing hormone agonist, activates dorsal motor nucleus neurons and gastric vagal efferent discharges. We investigated the gastric inflammation induced by AS and the modulation by intracisternal RX-77368 in rats. RX-77368 (50 ng/rat) or saline was injected followed, 1 h later, by laparotomy and small intestinal/cecal manipulation. The sham group had anesthesia alone. After 6 h, gastric emptying (GE) and the inflammation in gastric corpus were determined. AS inhibited GE by 72% vs. control and doubled the number of M1-like macrophage immunoreactive for major histocompatibility complex class II (MHCII; M1 marker) but not for cluster of differentiation 206 (CD206; M2 marker) (MHCII+/CD206-) while there was no change in M2-like macrophages (MHCII-/CD206+). AS increased mRNA levels of interleukin-1ß (IL-1ß) and tumor necrosis factor α (TNF-α) by 1.7- and 1.5-fold, respectively, in the gastric submucosa plus muscle layers and the infiltration of neutrophils labeled by myeloperoxidase by 9.5-fold in the muscularis externa. RX-77368 inhibited AS-related gastric changes while not altering these parameters in the sham group. There was a significant negative correlation between GE and IL-1ß (r = -0.46), TNF-α (r = -0.44), M1 macrophage (r = -0.82), and neutrophils (r = -0.91). The M2-like macrophages and IL-10 expression were unchanged by AS with intracisternal saline or RX-77368. These data indicate that AS activates gastric M1 macrophages and increases proinflammatory cytokines expression, which are prevented by central vagal activation and may contribute to the correlated dampening of postoperative gastric ileus.NEW & NOTEWORTHY MHCII+/CD206- (M1) and MHCII-/CD206+ (M2) constitute two distinct populations of macrophages that are in close apposition to the cholinergic neurons in the rat gastric myenteric plexus (MP). Abdominal surgery (6 h) activates M1 macrophage leading to inflammation in the gastric MP correlated with the delayed gastric emptying, which was abolished by central vagal stimulation via intracisternal injection of RX-77368. Vagal stimulation linked with the cephalic phase may have potential beneficial effects to curtail postoperative gastric ileus.

[A case report of chronic intestinal pseudo-obstruction with autoimmune autonomic ganglionopathy suspected from seropositive results for anti-ganglionic acetylcholine receptor antibody].

A 37-year-old woman who had previously been diagnosed with idiopathic chronic intestinal pseudo-obstruction (CIPO) at another hospital was admitted to our institution with severe abdominal pain. She had a history of several abdominal surgeries to treat ileus at the previous hospital, and contrast-enhanced computed tomography on admission revealed subileus without any apparent causes of obstruction. Total parenteral nutrition, a gastrointestinal prokinetic agent, and opiates reduced persistent pain;however, breakthrough pain continued. A neurologist at our hospital suggested autoimmune autonomic ganglionopathy (AAG) as a potential cause of CIPO. The patient was diagnosed with suspected AAG on the basis of seropositive results for anti-ganglionic acetylcholine receptor antibody. Intravenous immunoglobulin administration and plasma exchange were performed in combination with immunosuppressive drugs;however, her symptoms barely improved. Although percutaneous endoscopic gastrostomy and enterostomy were subsequently performed to reduce internal intestinal pressure, her pain relief was insufficient.

[Immunomodulatory aspects in the development, prophylaxis and therapy for postoperative ileus]. / Immunmodulatorische Aspekte bei der Entstehung, Prophylaxe und Therapie des postoperativen Ileus.

Postoperative ileus (POI) is defined as a transient episode of impaired gastrointestinal motility after abdominal surgery, which prevents effective transit of intestinal contents or tolerance of oral intake. This frequent postoperative complication is accompanied by a considerable increase in morbidity and hospitalisation costs. The aetiology of POI is multifactorial. Besides a suppression of peristalsis by inhibitory neuronal signalling and administration of opioids, particularly in the prolonged form, immunological processes play an important role. After surgical trauma, resident macrophages of the muscularis externa (ME) are activated leading to the liberation of proinflammatory mediators and a spreading of the inflammation along the entire gastrointestinal tract. To date, no prophylaxis or evidence-based single approach exists to treat POI. Since none of the current treatment approaches (i.e., prokinetic drug treatment) has provided a benefit in randomised trials, immunoregulatory interventions appear to be more promising in POI prevention or treatment. The present contribution gives an overview of immunological mechanisms leading to POI focusing on current and future therapeutic and prophylactic approaches.

Detection of anticonductive tissue autoantibodies in a patient with chronic intestinal pseudo-obstruction and sick sinus syndrome.

A 26-year-old patient was diagnosed as having chronic intestinal pseudo-obstruction with manometric and histopathologic features suggestive of an intestinal myopathy. Histology was characterized by smooth muscle degeneration without inflammatory or immune cells. The severe gut dysfunction required full parenteral nutritional support. After a few months, the patient developed symptomatic tachy-brady arrhythmia episodes with syncopes. A thorough diagnostic work-up led to a diagnosis of sick sinus syndrome, which was managed by pacemaker implantation and administration of ß-blockers. This led to a partial improvement in tachy-brady arrhythmia episodes. Nonetheless, the patient continued to experience sustained supraventricular tachyarrhythmia runs, poorly responsive to increasing ß-blocker doses. To investigate the origin of the cardiologic impairment, the patient was tested for anticonductive tissue autoantibodies, which were positive, thus supporting a possible autoimmune origin of the dysrhythmia. Other autoantibodies were negative. On the basis of these findings, the patient was treated with high-dose steroids, which were then tapered. The patient responded to the steroid treatment and did not experience further episodes of syncope and tachyarrhythmias. The severe gut dysfunction remained unchanged. This case highlights an association between severe gut dysfunction and cardiac conductive tissue abnormalities, with autoantibodies to conductive tissue possibly causing the dysrhythmia. The severe gut and heart (likely autoimmune-mediated) dysfunction presented in this case provides a basis to further assess a link between intestinal and cardiac abnormal rhythmicity.

Serum B-cell activating factor assessment in a population of Egyptian patients with systemic sclerosis.

BACKGROUND: Systemic sclerosis (SSc) is a rare systemic connective tissue disease characterized by abnormal fibroblast proliferation and micro-vascular inflammatory changes. AIM: To assess serum B-cell activating factor (BAFF) levels in patients with systemic sclerosis and to correlate this with disease features and disease severity. METHODS: This is a case-control study in which patients with the established diagnosis of SSc were recruited. The diagnosis of SSc was established according to the American Rheumatology Association 1980 criteria for the classification of scleroderma. Patients' assessment included evaluation of skin involvement using the Modified Rodnan score and disease severity using the Medsger score. Twenty-five healthy matching controls were included. The sandwich enzyme-linked immunosorbent assay technique was used for direct assessment of serum BAFF in patients and controls. RESULTS: The study included 60 patients (54 female and 6 male), with a mean age of 38.18 ± 12.06 years, with mean disease duration of 7.85 ± 4.075 years. Serum BAFF in patients ranged 98.2-5015 pg/mL with mean BAFF 1100 ± 835.4 pg/mL. In controls serum BAFF levels ranged 188.5-2314 pg/mL with mean BAFF 546.1 ± 471.1 pg/mL, showing a statistically significant elevation of serum BAFF levels in SSc patients (P = 0.0001) with insignificant correlation to skin disease or total Medsgar Score of the study population (P > 0.05). Serum BAFF levels showed significant correlation with episodes of pseudo-obstruction and methotrexate (MTX) use in the patients studied (P < 0.05). CONCLUSION: Serum BAFF levels were significantly elevated in patients with SSc irrespective of disease subtype, disease duration or age of patients. This elevation in serum BAFF significantly related to gastrointestinal track involvement and MTX therapy.

Depletion of enteric gonadotropin-releasing hormone is found in a few patients suffering from severe gastrointestinal dysmotility.

OBJECTIVE: Many patients, especially women, suffer from severe gastrointestinal pain and dysmotility for several years without being diagnosed. Depletion of gonadotropin-releasing hormone (GnRH) in the enteric nervous system (ENS) has been described in some patients. The aim of this study was to examine the expression of GnRH in ENS and antibodies against GnRH in serum, in a dysmotility patient cohort of southern Sweden. MATERIALS AND METHODS: All consecutive patients (n = 35) referred for laparoscopic full-thickness biopsy because of symptoms or signs of severe dysmotility between 1998 and 2009, or patients with a severe dysmotility disorder having had a bowel resection within the time frame, were considered for inclusion. In 22 cases, representative biopsy material containing ganglia was available, and these patients were included. Medical records were scrutinized. The expression of GnRH was determined by immunohistochemistry in bowel biopsies from these patients and in patients with carcinoma or diverticulosis without ENS histopathology. Antibodies against GnRH in serum were determined by ELISA in patients and controls. RESULTS: 14 patients were diagnosed with enteric dysmotility (ED) and 8 with chronic intestinal pseudo-obstruction due to varying etiology. Immunostained biopsies showed expression of GnRH in the ENS. A reduced expression of GnRH-containing neurons was found in 5 patients, as well as antibodies against GnRH in serum. 3 of these patients had a history of in vitro fertilization (IVF) using GnRH analogs. CONCLUSIONS: A subgroup of patients with severe dysmotility had a reduced expression of GnRH-containing neurons in the ENS and expressed antibodies against GnRH in serum.

The role of mast cell stabilization in treatment of postoperative ileus: a pilot study.

OBJECTIVES: Although postoperative ileus (POI) is considered multifactorial, intestinal inflammation resulting from manipulation-induced mast cell activation is recognized as an important pathophysiological mechanism. Therefore, mast cell stabilization may represent a new therapeutic approach to shortening POI. The aim of this paper was to study the effect of ketotifen, a mast cell stabilizer, on postoperative gastrointestinal transit in patients who underwent abdominal surgery. METHODS: In this pilot study, 60 patients undergoing major abdominal surgery for gynecological malignancy with standardized anesthesia were randomized to treatment with ketotifen (4 or 12 mg) or placebo. Patients were treated for 6 days, starting 3 days before surgery. Gastric emptying of liquids, selected as a primary outcome parameter, was measured 24 h after surgery using scintigraphy. Secondary end points were (scintigraphically assessed) colonic transit, represented as geometrical center of activity (segment 1(cecum) to 7(stool)) and clinical parameters. RESULTS: Gastric retention 1 h after liquid intake was significantly reduced by 12 mg (median 3% (1-7), P=0.01), but not by 4 mg ketotifen (18% (3-45), P=0.6) compared with placebo (16% (5-75)). Twenty-four hour colonic transit in placebo was 0.8 (0.0-1.1) vs. 1.2 (0.2-1.4) colon segments in the 12 mg ketotifen group (P=0.07). Abdominal cramps were significantly relieved in patients treated with 12 mg ketotifen, whereas other clinical parameters were not affected. CONCLUSIONS: Ketotifen significantly improves gastric emptying after abdominal surgery and warrants further exploration of mast cell stabilizers as putative therapy for POI.

Other autonomic neuropathies associated with ganglionic antibody.

The acetylcholine receptor ganglionic (G-AchR) antibody is a very specific serologic test for autoimmune autonomic ganglionopathy. The spectrum of autoimmune (or presumed to be autoimmune) autonomic disorders, however, is quite broad and positivity to this antibody has been reported in a variety of other conditions, albeit infrequent and with low titer. This review describes the autonomic neuropathies most frequently encountered in clinical practice in which an autoimmune etiology is suspected. They include a chronic form (pure autonomic failure) and limited autonomic neuropathies with predominant involvement of one neurotransmitter type (i.e., cholinergic vs. adrenergic) or one system (such as the gastrointestinal system) or a distal small fiber dysfunction. In each of these conditions, occasional positivity to the G-AchR antibody has been found, but the pathogenetic significance of such finding is still uncertain. Other antigens and antibodies yet to be identified are more likely to be responsible in these disorders.

Acute pan-dysautonomia as well as central nervous system involvement and peripheral neuropathies in a patient with systemic lupus erythematosus.

A 32-year-old woman was diagnosed with leucopenia in 2002, being antinuclear antibody, anti-DNA antibody, and antiphospholipid antibody positive, and she was administered low-dose aspirin. In July 2006, she was admitted to our hospital because of pyrexia and abdominal pain. Examination revealed paralytic ileus, absence of the pupillary light reflex, dyshidrosis and anuresis. In addition, with high-level interleukin-6 in cerebrospinal fluid, the sensory nerve conduction velocity was derivation impotence. She was subsequently diagnosed with systemic lupus erythematosus (SLE) with central nervous system involvement, peripheral neuropathy as well as acute pan-dysautonomia. After pulse corticosteroid therapy, paralytic ileus was improved, however, the urination disorder persisted, and syncope due to orthostatic hypotension became marked. Plasma exchange and a second course of pulse corticosteroid therapy were performed, and were ineffective, whereas intravenous cyclophosphamide was effective. This patient is a rare case of central nervous system, peripheral neuropathy as well as acute pan-dysautonomia with SLE.

Neurogenic chronic intestinal pseudo-obstruction: antineuronal antibody-mediated activation of autophagy via Fas.

BACKGROUND & AIMS: Activation of autoimmune pathways has been implicated as a contributing mechanism to the pathophysiology in some patients with chronic intestinal pseudoobstruction (CIP). In this study we tested the hypothesis that sera from a subpopulation of patients with CIP contain autoantibodies that activate autophagy via a Fas-dependent pathway in cultured human neuroblastoma SH-Sy5Y cells. METHODS: Twenty-five patients with established neurogenic CIP (20 women, 5 men; age range, 21-57 y) were investigated and circulating antineuronal antibodies to enteric neurons were found in 6 (24%) patients. The ability of antineuronal antibodies to induce autophagy was assessed using immunohistochemical, Western immunoblot, and molecular techniques. The presence of autophagosomes was monitored using a specific immunohistochemical marker, anti-microtubule-associated light chain immunoreactivity, and colocalization with mitochondrial- and Fas-activated death domain immunofluorescence using appropriate antibodies in cells exposed to sera from matched healthy controls and patients with neurogenic CIP. RESULTS: Exposure of SH-Sy5Y cells to sera from patients with CIP containing antineuronal antibodies revealed increased binding of autoimmune immunoglobulin (IgG class) to the surface of SH-Sy5Y cells and increased formation of autophagosomes showing colocalization with mitochondria and Fas-activated death domain compared with control sera. Pretreatment of sera with either protein L agarose beads or a soluble Fas receptor (extracellular domain) chimera prevented the stimulation of autophagy. CONCLUSIONS: We provide novel evidence that antineuronal antibodies may contribute to neuronal dysfunction observed in a subset of patients with neurogenic CIP via autoantibody-mediated activation of autophagy involving the Fas receptor complex.

Chronic intestinal pseudo-obstruction in patients with systemic lupus erythematosus: report of four cases.

Chronic intestinal pseudo-obstruction (CIPO), a recently recognized manifestation of systemic lupus erythematosus (SLE) with only 23 cases reported in the English literature, may appear as a complication or as the initial presentation of SLE and usually occurs during the setting of an active lupus. The pathogenic mechanism in SLE is unknown. We describe four additional cases with clinical, radiological, and manometric features of CIPO. As SLE-related CIPO usually responds to treatment with high doses of corticosteroids and/or immunosuppressive and prokinetic agents, a high level of awareness of this complication is needed to avoid unnecessary surgical intervention.

Small bowel gastric metaplasia: a report of three cases in children.

AIMS: To report three children displaying gastric metaplasia antral pyloric type of the small bowel mucosa. METHODS: Analysis of clinical, histopathological and immunohistochemical data. RESULTS: The first patient was a 14-year-old girl with history of chronic intestinal pseudo-obstruction and chronic jejunitis; the second patient was a 6-year-old girl with a long-lasting jejunostomy; and the third patient was a 5-year-old girl with ileal-rectal anastomosis. The foci of gastric metaplasia were obvious with H&E-stained sections. The cells at the gastric metaplasia mucosa proved to be MUC-1 and sialyl-Tn positive by immunohistochemistry and they were in a pattern that was different from that of the adjacent mucosa; the cells were autofluorescent in H&E-stained sections. CONCLUSIONS: Gastric metaplasia of the small bowel mucosa in these cases seems to have resulted from chronic inflammation and persistent regenerative activity. This has rarely been reported outside Crohn disease, and if ever in children.

Chronic intestinal pseudo-obstruction due to buserelin-induced formation of anti-GnRH antibodies.

BACKGROUND & AIMS: A 30-year-old woman, treated with buserelin, an analogue of gonadotropin-releasing hormone (GnRH) (also called luteinizing hormone-releasing hormone, LH-RH), developed chronic intestinal pseudo-obstruction (CIPO). The sudden onset of this disease in a previously healthy woman perplexed us. CIPO refers to a gastrointestinal disorder that can have a variety of causes, such as drugs, among others. Thus, we wanted to examine whether in this patient the development of CIPO is related to the treatment with buserelin. METHODS: The patient was examined using esophagogastroduodenoscopy, esophageal, and antroduodenojejunal manometry, gastric emptying tests, and histologic analyses and immunohistochemistry on full-thickness biopsies including staining with anti-GnRH antibody. Plasma samples were examined by the standard serologic analyses and specifically for the occurrence of anti-GnRH antibodies by enzyme-linked immunosorbent assay methods. RESULTS: CIPO was diagnosed based on symptoms (abdominal pain, vomiting, and constipation), and the results of the clinical examinations, such as signs of esophageal aperistalsis, delayed gastric emptying, and small intestinal bursts. Histologic examination revealed a decreased number of myenteric neurons as well as increased neuronal degeneration and an abnormal immune profile. There was a loss of GnRH-containing neurons. The patient had high plasma titers of anti-GnRH antibodies, which occurred on the occasions of the treatment with buserelin. CONCLUSIONS: Our findings suggest that the patient has developed CIPO due to buserelin-induced formation of anti-GnRH antibodies destroying GnRH-producing neurons of the myenteric plexus.