Paediatric Intestinal Pseudo-obstruction: Evidence and Consensus-based Recommendations From an ESPGHAN-Led Expert Group

European Consensus on Malabsorption-UEG & SIGE, LGA, SPG, SRGH, CGS, ESPCG, EAGEN, ESPEN, and ESPGHAN: Part 2: Screening, Special Populations, Nutritional Goals, Supportive Care, Primary Care Perspective

Malabsorption is a complex and multifaceted condition characterised by the defective passage of nutrients into the blood and lymphatic streams. Several congenital or acquired disorders may cause either selective or global malabsorption in both children and adults, such as cystic fibrosis, exocrine pancreatic insufficiency (EPI), coeliac disease (CD) and other enteropathies, lactase deficiency, small intestinal bacterial overgrowth (SIBO), autoimmune atrophic gastritis, Crohn's disease, and gastric or small bowel resections. Early recognition of malabsorption is key for tailoring a proper diagnostic work-up for identifying the cause of malabsorption. Patient's medical and pharmacological history are essential for identifying risk factors. Several examinations like endoscopy with small intestinal biopsies, non-invasive functional tests, and radiologic imaging are useful in diagnosing malabsorption. Due to its high prevalence, CD should always be looked for in case of malabsorption with no other obvious explanations and in high-risk individuals. Nutritional support is key in management of patients with malabsorption; different options are available, including oral supplements, enteral or parenteral nutrition. In patients with short bowel syndrome, teduglutide proved effective in reducing the need for parenteral nutrition, thus improving the quality of life of these patients. Primary care physicians have a central role in early detection of malabsorption and should be involved into multidisciplinary teams for improving the overall management of these patients. In this European consensus, involving 10 scientific societies and several experts, we have dissected all the issues around malabsorption, including the definitions and diagnostic testing (Part 1), high-risk categories and special populations, nutritional assessment and management, and primary care perspective (Part 2).

Gastrointestinal Motility Disorders in the Neonate

Gastrointestinal (GI) motility disorders in term and premature infants may occur at different times of gestation. Knowledge of normal neuromuscular development can help clinicians determine the cause of GI dysmotility and prognosis in infants born with congenital anomalies. Various developmental abnormalities and premature gestational age can alter normal GI motility, requiring further advanced testing and management. A multidisciplinary approach is often needed to care for these patients.

Mitochondrial Neurogastrointestinal Encephalomyopathy (MNGIE) Phenotype Associated With Unique Compound Heterozygous POLG Variants: Case Presentation and Review of the Literature

We report a teenage patient with a delayed diagnosis of compound heterozygous POLG pathogenic variants [(POLG c. 1943 C>G, p.P648R) and (POLG c. 679 C>T, p.R227W)] who presented with fatigue and neuropathy, as well as long standing malnutrition and cachexia, erroneously attributed to an eating disorder. She experienced multiple bowel perforations and pathologic examination revealed jejunal diverticula and features of visceral neuromyopathy. In addition to ganglion cell mega-mitochondrial inclusions, there were multiple foci of interrupted muscularis mucosae, an alteration not previously recognized in the intestines of patients with primary mitochondrial disorders. We provide a detailed account of the gastrointestinal pathologic findings in this patient and compare with prior cases of Mitochondrial Neurogastrointestinal Encephalomyopathy (MNGIE) phenotypes.

Dynamical features of smooth muscle actin pathological mutants: The arginine-257(258)-Cysteine cases

The R257(8)C mutation in smooth muscle actins, ACTG2 and ACTA2, is the most frequent cause of severe genetic diseases: namely, visceral myopathy, and familial thoracic aortic aneurysms and dissections, which respectively, stem from impairment of the visceral and vascular muscle. The molecular mechanisms underlying such pathologies are not fully elucidated. In the absence of experimental data of WT and mutated actins in their monomeric (g-) and filamentous (f-) form, molecular dynamics can shed light on the role of the R257(8)C in protein structure and dynamics. Analysis of g-actins does not show significant differences between WT and mutated proteins suggesting the correct monomers folding. On the contrary, mutated filaments are destabilized. Subunits of R257C f-ACTG2 adopt non optimal angles and in R258C f-ACTA2 we observe depolymerization already in the simulated time frame. Overall, our data points to a crucial role of residue R257(8) in actin structure and dynamics, in particular when the protein assembles into the filament.

Identifying and treating CLN3 disease outside the central nervous system

CLN3 disease causes profound neurological deficits in affected children, but less well recognized are a variety of peripheral neuromuscular and gastrointestinal problems. We hypothesized that in addition to central nervous system (CNS) degeneration, CLN3 deficiency may also directly affect neuronal and/or glial cell populations in the rest of the body. Therefore, we examined the neuromuscular and enteric nervous system in Cln3 Δex7/8 mice. There was no overt sciatic nerve axon loss or demyelination in Cln3 Δex7/8 mice, but significant loss of terminal Schwann cells (tSCs) at lower limb neuromuscular junctions (NMJ), and progressive NMJ denervation. This was accompanied by pronounced myofiber atrophy, with fewer and displaced myofibril nuclei, with similar pathology seen in a human CLN3 muscle biopsy. Atrophy was also evident in bowel smooth muscle with Cln3 Δex7/8 mice displaying slow bowel transit, and significant loss of both enteric neurons and glial cells throughout the bowel. Similar enteric pathology was evident at autopsy in the small intestine and colon of a human CLN3 case. Neonatal administration of intravenous gene therapy to Cln3 Δex7/8 mice using an AAV9-hCLN3 vector completely prevented tSCs and NMJ pathology, atrophy of both skeletal and smooth muscle, positively impacted bowel transit and largely prevented the loss of enteric neurons and glia. These findings reveal an underappreciated, but profound, impact of CLN3 disease outside the CNS and suggest these novel aspects of disease may be treatable using gene therapy.

Graphical abstract

Gene therapy ameliorates bowel dysmotility and enteric neuron degeneration and extends survival in lysosomal storage disorder mouse models

Children with neurodegenerative disease often have debilitating gastrointestinal symptoms. We hypothesized that this may be due at least in part to underappreciated degeneration of neurons in the enteric nervous system (ENS), the master regulator of bowel function. To test this hypothesis, we evaluated mouse models of neuronal ceroid lipofuscinosis type 1 and 2 (CLN1 and CLN2 disease, respectively), neurodegenerative lysosomal storage disorders caused by deficiencies in palmitoyl protein thioesterase-1 and tripeptidyl peptidase-1, respectively. Both mouse lines displayed slow bowel transit in vivo that worsened with age. Although the ENS appeared to develop normally in these mice, there was a progressive and profound loss of myenteric plexus neurons accompanied by changes in enteric glia in adult mice. Similar pathology was evident in colon autopsy material from a child with CLN1 disease. Neonatal administration of adeno-associated virus-mediated gene therapy prevented bowel transit defects, ameliorated loss of enteric neurons, and extended survival in mice. Treatment after weaning was less effective than treating neonatally but still extended the lifespan of CLN1 disease mice. These data provide proof-of-principle evidence of ENS degeneration in two lysosomal storage diseases and suggest that gene therapy can ameliorate ENS disease, also improving survival.

Glutamine Supplementation as a Novel Metabolic Therapeutic Strategy for LIG3-Dependent Chronic Intestinal Pseudo-Obstruction

BACKGROUND & AIMS

We recently identified a recessive syndrome due to DNA ligase 3 (LIG3) mutations in patients with chronic intestinal pseudo-obstruction, leukoencephalopathy, and neurogenic bladder. LIG3 mutations affect mitochondrial DNA maintenance, leading to defective energy production. We aimed at identifying altered molecular pathways and developing possible targeted treatments to revert/ameliorate the cellular energy impairment.

METHODS

Whole transcriptome analysis was performed on patient-derived fibroblasts total RNA and controls. Mitochondrial function, mitophagy, and l-glutamine supplementation effects were analyzed by live cell analysis, immunostaining, and Western blot. Patients were treated with Dipeptiven (Fresenius-Kabi) according to standard protocols. Patients' symptoms were analyzed by the Gastrointestinal Symptom Rating Scale questionnaire.

RESULTS

We identified deregulated transcripts in mutant fibroblasts vs controls, including overexpression of genes involved in extracellular matrix development and remodeling and mitochondrial functions. Gut biopsy specimens of LIG3-mutant patients documented collagen and elastic fiber accumulation. Mutant fibroblasts exhibited impaired mitochondrial mitophagy indicative of dysfunctional turnover and altered Ca2+ homeostasis. Supplementation with l-glutamine (6 mmol/L), previously shown to increase mitochondrial DNA-defective cell survival, improved growth rate and adenosine 5'-triphosphate production in LIG3-mutant fibroblasts. These data led us to provide parenterally a dipeptide containing l-glutamine to 3 siblings carrying biallelic LIG3 mutations. Compared with baseline, gastrointestinal and extra-gastrointestinal symptoms significantly improved after 8 months of treatment.

CONCLUSIONS

LIG3 deficiency leads to mitochondrial dysfunction. High levels l-glutamine supplementation were beneficial in LIG3-mutant cells and improved symptom severity without noticeable adverse effects. Our results provide a proof of concept to design ad hoc clinical trials with l-glutamine in LIG3-mutant patients.

Incidence, diagnostics, therapeutic management and outcomes of paediatric intestinal pseudo-obstruction in the Netherlands: A 20-year retrospective cohort study

OBJECTIVES

To describe incidence, clinical course, diagnostic and therapeutic management and long-term follow-up of paediatric intestinal pseudo-obstruction (PIPO) in the Netherlands between 2000 and 2020.

METHODS

Multicenter, national, retrospective, observational study including patients aged <18 years diagnosed with PIPO and treated between 2000 and 2020 in Dutch academic medical centres. Outcomes included demographics, incidence, symptoms, diagnostic- and treatment methods used during follow-up, number of hospital admissions and mortality.

RESULTS

Between 2000 and 2020, 43 children (median age 120 months, range 13-301, 54% female) were diagnosed with PIPO in the Netherlands. Mean incidence was 0.008/100,000/years (range 0/100 000-0.029/100 000). Twenty-six patients developed PIPO in the neonatal period. Initial symptoms were vomiting (n = 21/35, 60%) and abdominal distension (n = 14/35, 40%). Diagnostic strategies included imaging, manometry, histopathology, metabolic- and genetic screening, endoscopy and exploratory surgery. Treatment was divided in nutritional support, pharmacotherapy, colonic irrigation and surgical interventions, of which nutrition and surgery were the cornerstones for care. During the observed study period, the median number of hospital admissions was 22.5 (range 1-176) with a median of 157.5 days (range 3-840) during 20-year follow-up. Two patients (6%) died: one from sepsis and one due to a severe underlying neurological disease. Heterogeneity in diagnostic- en treatment methods existed between patients.

CONCLUSIONS

PIPO is a rare, long-lasting complex disease requiring a high number of diagnostic and therapeutic interventions and hospital admissions. However, mortality rate is relatively low. Based on our results, we recommend centralization and standardization of care for this complex rare disease.

When parenteral nutrition is the answer: The case of pediatric intestinal rehabilitation

In pediatric patients with intestinal failure, parenteral nutrition is lifesaving but also has several associated risks. The goals of intestinal rehabilitation include promoting growth, minimizing complications associated with intestinal failure, and reaching enteral autonomy, if possible. Pediatric intestinal rehabilitation programs are interdisciplinary teams that strive to provide optimal care for children dependent on parenteral nutrition. The provision of parenteral nutrition requires close monitoring of patients' growth, nutrition concerns, clinical status, and laboratory parameters. Recent advances in the field of intestinal rehabilitation include new lipid emulsions, considerations regarding enteral feeding, advances in micronutrient provision, and central venous catheter preservation techniques. Challenges in the field remain, including improving overall quality of life with home parenteral nutrition administration and preventing recently recognized complications such as chronic intestinal inflammation.

Pediatric to adult transition care in neurogastroenterology and motility: A position paper from the American Neurogastroenterology and Motility Society and European Society of Neurogastroenterology and Motility

Transition services-programs that support adolescents and young adults (AYAs) as they move from a child-centered to a more autonomous, adult-orientated healthcare system-have been associated with improved short- and long-term healthcare outcomes. Unfortunately, there is a paucity of evidence exploring transition services within the neurogastroenterology and motility (NGM) field. The overall aim of this article, endorsed by the American Neurogastroenterology and Motility Society and European Society of Neurogastroenterology and Motility, is to promote a discussion about the role of transition services for patients with NGM disorders. The AYAs addressed herein are those who have: (a) a ROME positive disorder of gut-brain interaction (DGBI), (b) a primary or secondary motility disorder (including those with motility disorders that have been surgically managed), or (c) an artificial feeding requirement (parenteral or enteral tube feeding) to manage malnutrition secondary to categories (a) or (b). The issues explored in this position paper include the specific physical and psychological healthcare needs of patients with NGM disorders; key healthcare professionals who should form part of a secondary care NGM transition service; the triadic relationship between healthcare professionals, caregivers, and patients; approaches to selecting patients who may benefit most from transition care; methods to assess transition readiness; and strategies with which to facilitate transfer of care between healthcare professionals. Key areas for future research are also addressed, including the construction of NGM-specific transition readiness questionnaires, tools to assess post-transfer healthcare outcomes, and educational programs to train healthcare professionals about transition care in NGM.

Pediatric Chronic Intestinal Failure: Something Moving?

Pediatric chronic intestinal failure (PIF) is a rare and heterogeneous condition characterized by the inability of the patient's intestine to adequately absorb the required fluids and/or nutrients for growth and homeostasis. As a result, patients will become dependent on home parenteral nutrition (HPN). A MEDLINE search was performed in May 2024 with keywords "intestinal failure", "parenteral nutrition" and "pediatric". Different underlying conditions which may result in PIF include short bowel syndrome, intestinal neuromuscular motility disorders and congenital enteropathies. Most common complications associated with HPN are catheter-related bloodstream infections, catheter-related thrombosis, intestinal failure-associated liver disease, small intestinal bacterial overgrowth, metabolic bone disease and renal impairment. Treatment for children with PIF has markedly improved with a great reduction in morbidity and mortality. Centralization of care in specialist centers and international collaboration between centers is paramount to further improve care for this vulnerable patient group. A recently promising medical therapy has become available for children with short bowel syndrome which includes glucagon-like peptide 2, a naturally occurring hormone which is known to delay gastric emptying and induce epithelial proliferation. Despite advances in curative and supportive treatment, further research is necessary to improve nutritional, pharmacological and surgical care and prevention of complications associated with parenteral nutrition use.

Nutritional Management of Pediatric Gastrointestinal Motility Disorders

Normal and optimal functioning of the gastrointestinal tract is paramount to ensure optimal nutrition through digestion, absorption and motility function. Disruptions in these functions can lead to adverse physiological symptoms, reduced quality of life and increased nutritional risk. When disruption or dysfunction of neuromuscular function occurs, motility disorders can be classified depending on whether coordination or strength/velocity of peristalsis are predominantly impacted. However, due to their nonspecific presenting symptoms and overlap with sensory disruption, they are frequently misdiagnosed as disorders of the gut-brain interaction. Motility disorders are a prevalent issue in the pediatric population, with management varying from medical therapy to psychological therapy, dietary manipulation, surgical intervention or a multimodal approach. This narrative review aims to discuss the dietary management of common pediatric motility disorders including gastroesophageal reflux, esophageal atresia, achalasia, gastroparesis, constipation, and the less common but most severe motility disorder, pediatric intestinal pseudo-obstruction.

Antroduodenal manometry findings in children with suspected pediatric intestinal pseudo-obstruction

BACKGROUND

In 2018 diagnostic criteria for pediatric intestinal pseudo-obstruction (PIPO) were established. Neuromuscular dysfunction of the gastrointestinal tract is one of these, and often examined through antroduodenal manometry (ADM). There is little data on antroduodenal manometries in children. Our objectives were to retrospectively apply these criteria to children evaluated for suspected motility disorder, to reevaluate the ADM patterns and compare children who did and did not meet the PIPO criteria and also with healthy adults.

METHODS

Children with a suspected gastrointestinal motility disorder previously investigated with 24-h 8-lead ADM were reevaluated by applying the 2018 ESPGHAN/NASPGHAN PIPO diagnostic criteria and the 2018 ANMS-NASPGHAN guidelines. ADM findings were compared between children who retrospectively fulfilled a PIPO diagnosis, children who did not, and a control group of healthy adults.

KEY RESULTS

Of 34 children (age 7.9 (±5.1) years, 18 males), 12 retrospectively fulfilled the 2018 PIPO diagnostic criteria. Twenty-five children (10 in the PIPO group) had abnormal diagnostic findings on ADM, whereas 9 (2 in the PIPO group) had no such findings. A PIPO diagnosis implied a significantly higher degree of abnormal ADM patterns (2.33 vs. 1.23, p = 0.02). There were no major differences in quantitative ADM measurements between the groups except higher pressures in children.

CONCLUSIONS AND INFERENCES

Children who retrospectively fulfilled a PIPO diagnosis had a significantly higher abundance of abnormal ADM findings compared with symptomatic children without PIPO and healthy adults. Our data indicate a need for set criteria for evaluation of ADM in children with suspected PIPO.

A lmod1a mutation causes megacystis microcolon intestinal hypoperistalsis in a CRISPR/Cas9-modified zebrafish model

PURPOSE

Megacystis microcolon intestinal hypoperistalsis syndrome (MMIHS) is defined as a congenital visceral myopathy with genetic mutations. However, the etiology and pathophysiology are not fully understood. We aimed to generate a gene leiomodin-1a (lmod1a) modification technique to establish a zebrafish model of MMIHS.

METHODS

We targeted lmod1a in zebrafish using CRISPR/Cas9. After confirming the genotype, we measured the expression levels of the target gene and protein associated with MMIHS. A gut transit assay and spatiotemporal mapping were conducted to analyze the intestinal function.

RESULTS

Genetic confirmation showed a 5-base-pair deletion in exon 1 of lmod1a, which caused a premature stop codon. We observed significant mRNA downregulation of lmod1a, myh11, myod1, and acta2 and the protein expression of Lmod1 and Acta2 in the mutant group. A functional analysis of the lmod1a mutant zebrafish showed that its intestinal peristalsis was fewer, slower, and shorter in comparison to the wild type.

CONCLUSION

This study showed that targeted deletion of lmod1a in zebrafish resulted in depletion of MMIHS-related genes and proteins, resulting in intestinal hypoperistalsis. This model may have the potential to be utilized in future therapeutic approaches, such as drug discovery screening and gene repair therapy for MMIHS.

Characterization of an in vitro model of intestinal cells as a test-bed for mCIPO therapies

Chronic Intestinal Pseudo-Obstruction in children (CIPO) comprises a group of ultra-rare and debilitating diseases characterized by severe motility defects affecting the entire digestive tract. With limited effective therapies, particularly for myopathic CIPO, we aim at characterizing the behavior of an intestinal smooth muscle cell line undergoing a set of chemical and physical stimulations, to assess their effect. To this end, we adopted healthy Human Intestinal Smooth Muscle Cells, plated on standard coverslips and, for the first time, Micro Electrode Arrays (MEAs). After obtaining stable cultures, we performed pharmacological and electrical stimulation, evaluating the contraction level as readout. We found an increase in the contraction levels ascribable to stimulation respect to basal condition. Our results can be considered introductory for new therapies for treating intestine motility disorders.

Time is Gut. Approaching Intestinal Leiomyositis: Case Presentation and Literature Review

T-lymphocytic intestinal leiomyositis is a rare cause of "pediatric intestinal pseudo-obstructions." Diagnosis may be difficult and requires full-thickness bowel biopsies during laparotomy or laparoscopy with possible enterostomy. Currently, immunosuppressive therapy is the only available treatment. A delay in diagnosis and therapy may negatively affect the prognosis because of ongoing fibrotic alterations; therefore, early diagnosis and consequent treatment are crucial. This review summarizes the available information on the nosology, diagnostic steps, and treatment modalities. Here, we report the youngest case of enteric leiomyositis reported in the last two decades and analyze its management by reviewing previous cases.

Megacystis-microcolon-intestinal hypoperistalsis syndrome: don't forget the bladder

PURPOSE

Megacystis-microcolon-intestinal hypoperistalsis syndrome (MMIHS) is a well described clinical condition, but reports are focused on microcolon and intestinal hypoperistalsis, while data on bladder management are scant. Aim of the study is to present urological concerns in MMIHS.

METHODS

Retrospective evaluation of clinical data on urological management of MMIHS patients treated in the last 10 years.

RESULTS

Six patients were enrolled (3 male, 3 female). Three girls had prenatal diagnosis of megacystis (1 vesicoamniotic shunt was placed). All patients had genetic diagnosis: 5 had ACTG2 gene mutations and 1 MYH11 mutation. All patients were addressed to our attention for urinary symptoms, such as urinary retention, urinary tract infections, acute renal injury. Two patients presented frequent stoma prolapses. All children underwent a complete urological evaluation, and then started a bladder management protocol (clean intermittent catheterization, via urethra or cystostomy-tube placement), with improvement of urinary infections, upper urinary tract dilation and stoma prolapses, if present. All patients had good renal function at last follow-up.

CONCLUSION

We believe that MMIHS patients must be addressed soon and before onset of symptoms for a multidisciplinary evaluation, including an early assessment by a pediatric urologist expert in functional disorder, to preserve renal function at its best.

Megacystis microcolon intestinal hypoperistalsis syndrome (MMIHS): challenges in diagnosis and management

Megacystis microcolon intestinal hypoperistalsis syndrome (MMIHS) is a rare, congenital functional intestinal obstruction, characterised by megacystis (bladder distention in the absence of mechanical obstruction), microcolon and intestinal hypoperistalsis (dysmotility).We are reporting a case of a female child with normal antenatal course who presented with recurrent episodes of abdominal distension since the second day of life and underwent negative exploratory laparotomy on multiple occasions. She also had urinary retention with a grossly distended bladder, requiring drainage by clean intermittent catheterisation. Surgical procedures for bowel decompression, including gastrostomy and ileostomy, were carried out without success. Genetic analysis revealed a mutation in the human smooth muscle (enteric) gamma-actin gene (ACTG2 gene), clinching the diagnosis of MMIHS. The patient was managed with parenteral nutrition and prokinetic medications and tolerated jejunostomy feeds for a brief period before she succumbed to the illness.Female neonates or infants presenting with abdominal distension and dilated urinary tract should be investigated for MMIHS early on. A timely diagnosis will enable the early involvement of a multidisciplinary team to provide the best options available for management.

Gastrointestinal Ostomies in Children: A Primer for the Pediatrician

Despite the advancement of medical therapies in the care of the preterm neonate, in the management of short bowel syndrome and the control of pediatric inflammatory bowel disease, the need to create fecal ostomies remains a common, advantageous treatment option for many medically complex children.

Targeting the Gut: A Systematic Review of Specific Drug Nanocarriers

The intestine is essential for the modulation of nutrient absorption and the removal of waste. Gut pathologies, such as cancer, inflammatory bowel diseases (IBD), irritable bowel syndrome (IBS), and celiac disease, which extensively impact gut functions, are thus critical for human health. Targeted drug delivery is essential to tackle these diseases, improve therapy efficacy, and minimize side effects. Recent strategies have taken advantage of both active and passive nanocarriers, which are designed to protect the drug until it reaches the correct delivery site and to modulate drug release via the use of different physical-chemical strategies. In this systematic review, we present a literature overview of the different nanocarriers used for drug delivery in a set of chronic intestinal pathologies, highlighting the rationale behind the controlled release of intestinal therapies. The overall aim is to provide the reader with useful information on the current approaches for gut targeting in novel therapeutic strategies.

Gastrointestinal radionuclide imaging in pediatric age group

Pediatric gastrointestinal imaging plays a crucial role in evaluating and managing digestive system disorders in children. This comprehensive review dives into the nuances of pediatric gastrointestinal imaging techniques, focusing on three specific modalities: gastric emptying scintigraphy (GES), intestinal transit scintigraphy (ITS), and gastrointestinal bleeding scintigraphy. GES involves real-time monitoring of stomach emptying using radiotracers and gamma camera technology. While challenges exist in standardizing protocols due to age-specific meal compositions, GES remains pivotal in diagnosing motility disorders, gastroesophageal reflux, and abdominal pain in children. ITS, utilizing [67Ga], provides insights into gastrointestinal motility disorders such as Hirschsprung disease. It aids in whole-gut transit evaluation, guiding surgical interventions and improving long-term clinical outcomes. Gastrointestinal bleeding scintigraphy, employing [99mTc], assists in diagnosing conditions like Meckel's diverticulum and occult bleeding, offering continuous monitoring to pinpoint the bleeding site along the entire gastrointestinal tract. SPECT-CT improves the accuracy and the standards of care. Each technique's protocol details, clinical indications, and diagnostic capabilities are thoroughly discussed, highlighting the importance of these non-invasive, functional imaging modalities in pediatric gastroenterology.

Chronic intestinal pseudo-obstruction: associations with gut microbiota and genes expression of intestinal serotonergic pathway

BACKGROUND

Pediatric chronic intestinal pseudo-obstruction (PIPO) is a rare disease characterized by symptoms and radiological signs suggestive of intestinal obstruction, in the absence of lumen-occluding lesions. It results from an extremely severe impairment of propulsive motility. The intestinal endocrine system (IES) jointly with the enteric nervous system (ENS) regulates secreto-motor functions via different hormones and bioactive messengers/neurotransmitters. The neurotransmitter 5-hydroxytryptamine (5-HT) (or serotonin) is linked to intestinal peristalsis and secretory reflexes. Gut microbiota and its interplay with ENS affect 5-HT synthesis, release, and the subsequent serotonin receptor activation. To date, the interplay between 5-HT and gut microbiota in PIPO remains largely unclear. This study aimed to assess correlations between mucosa associated microbiota (MAM), intestinal serotonin-related genes expression in PIPO. To this purpose, biopsies of the colon, ileum and duodenum have been collected from 7 PIPO patients, and 7 age-/sex-matched healthy controls. After DNA extraction, the MAM was assessed by next generation sequencing (NGS) of the V3-V4 region of the bacterial RNA 16 S, on an Illumina Miseq platform. The expression of genes implicated in serotoninergic pathway (TPH1, SLC6A4, 5-HTR3 and 5-HTR4) was established by qPCR, and correlations with MAM and clinical parameters of PIPO have been evaluated.

RESULTS

Our results revealed that PIPO patients exhibit a MAM with a different composition and with dysbiosis, i.e. with a lower biodiversity and fewer less connected species with a greater number of non-synergistic relationships, compared to controls. qPCR results revealed modifications in the expression of serotonin-related intestinal genes in PIPO patients, when compared to controls. Correlation analysis do not reveal any kind of connection.

CONCLUSIONS

For the first time, we report in PIPO patients a specific MAM associated to underlying pathology and an altered intestinal serotonin pathway. A possible dysfunction of the serotonin pathway, possibly related to or triggered by an altered microbiota, may contribute to dysmotility in PIPO patients. The results of our pilot study provide the basis for new biomarkers and innovative therapies targeting the microbiota or serotonin pathways in PIPO patients.

Chronic intestinal pseudo-obstruction in adults: A practical guide to identify patient subgroups that are suitable for more specific treatments

Chronic intestinal pseudo-obstruction is a rare and heterogeneous syndrome characterized by recurrent symptoms of intestinal obstruction with radiological features of dilated small or large intestine with air/fluid levels in the absence of any mechanical occlusive lesion. Several diseases may be associated with chronic intestinal pseudo-obstruction and in these cases, the prognosis and treatment are related to the underlying disease. Also, in its "primary or idiopathic" form, two subgroups of patients should be determined as they require a more specific therapeutic approach: patients whose chronic intestinal pseudo-obstruction is due to sporadic autoimmune/inflammatory mechanisms and patients whose neuromuscular changes are genetically determined. In a context of a widely heterogeneous adult population presenting chronic intestinal pseudo-obstruction, this review aims to summarize a practical diagnostic workup for identifying definite subgroups of patients who might benefit from more specific treatments, based on the etiology of their underlying condition.

The Clinical Utility of Antroduodenal Manometry in the Evaluation of Children with Upper Gastrointestinal Symptoms

OBJECTIVES

Antroduodenal manometry (ADM) measures antral and small bowel motility and is clinically used to evaluate upper gastrointestinal (UGI) symptoms. We aimed to evaluate its utility in guiding treatment, predicting response, and association with clinical findings.

METHODS

Retrospective review of 200 children undergoing ADM. ADM interpretation and parameters were compared to outcomes (response to first therapy after ADM and overall response), predominant symptom (group A, abdominal distention and/or vomiting and group B, abdominal pain and/or nausea), etiology (idiopathic or with known comorbidity), and ADM indication [suspected chronic intestinal pseudo-obstruction (CIPO) or unexplained UGI symptoms].

RESULTS

We found an association between a normal intestinal phase III of the migrating motor complex (MMC) and idiopathic etiology, group B symptoms and unexplained UGI symptoms. No variable was associated with initial successful response. However, normal small bowel phase III of the MMC and idiopathic etiology were associated with overall successful response to treatment (including feeding tolerance and weaning of parenteral nutrition). No antral ADM parameter was associated with outcomes or other comparisons. The time to overall successful treatment response was significantly shorter in patients with a normal ADM and presence of a normal phase III of the MMC.

CONCLUSIONS

The presence of the phase III of the MMC was the single ADM parameter predictive of overall treatment response, also associated to group B symptoms and idiopathic etiology. Our findings suggest that small bowel ADM parameters are more useful to predict outcomes and ADM should be performed primarily in patients presenting with abdominal distention and/or vomiting and those being evaluated for CIPO.

Recent advances in the treatment of gastrointestinal motility disorders in children

INTRODUCTION

Pediatric gastrointestinal motility disorders represent some of the most challenging clinical conditions with largely undefined pathogenetic pathways and therefore limited therapeutic options. Herein, we provide an overview of the recent advances in treatment options for these disorders and their clinical impact.

AREAS COVERED

PubMed and Medline databases were searched for relevant articles related to the treatment of achalasia, esophageal atresia, gastroparesis, PIPO and constipation published between 2017 and 2022. In this article, we review and summarize recent advances in management of gastrointestinal motility disorders in children with a particular focus on emerging therapies as well as novel diagnostic modalities that help guide their application or develop new, more targeted treatments.

EXPERT OPINION

Gastrointestinal motility disorders represent one of the most challenging conundrums in pediatric age and despite significant advances in investigative tools, the palette of treatment options remain limited. Overall, while pharmacological options have failed to bring a curative solution, recent advances in minimal invasive therapeutic and diagnostic techniques have emerged as potential keys to symptom and quality of life improvement, such as ENDOFLIP, POEM, cine-MRI, fecal microbiota transplantation.

Small Bowel Transit Scintigraphy in Children With Pediatric Intestinal Pseudo-Obstruction

INTRODUCTION

Objective evidence of small intestinal dysmotility is a key criterion for the diagnosis of pediatric intestinal pseudo-obstruction (PIPO). Small bowel scintigraphy (SBS) allows for objective measurement of small bowel transit (SBT), but limited data are available in children. We aimed to evaluate the utility of SBS in children suspected of gastrointestinal dysmotility.

METHODS

Patients undergoing gastric emptying studies for suspected foregut dysmotility, including PIPO, from 2016 to 2022 at 2 tertiary children's hospitals were recruited to an extended protocol of gastric emptying studies to allow for assessment of SBT. PIPO was classified based on antroduodenal manometry (ADM). SBT was compared between PIPO and non-PIPO patients. Scintigraphic parameters were assessed and correlated against ADM scores.

RESULTS

Fifty-nine patients (16 PIPO and 43 non-PIPO diagnoses) were included. SBS was performed with liquid and solid meals in 40 and 26 patients, respectively. As compared to the non-PIPO group, PIPO patients had a significantly lower median percentage of colonic filling at 6 hours, with both liquid (48% vs 83%) and solid tests (5% vs 65%). SBT in PIPO patients with myopathic involvement was significantly slower than in patients with neuropathic PIPO, both for liquid and solid meal. A significant correlation was found between solid SBT and ADM scores (r = -0.638, P = 0.036).

DISCUSSION

SBS provides a practically feasible assessment of small intestinal motility. It shows a potential utility to help diagnose and characterize PIPO. SBS seems most discriminative in PIPO patients with myopathic involvement. Studies in a larger pediatric population and across different ages are required.

Evaluating the molecular and genetic mechanisms underlying gut motility disorders

INTRODUCTION

Gastrointestinal (GI) motility disorders comprise a wide range of different diseases affecting the structural or functional integrity of the GI neuromusculature. Their clinical presentation and burden of disease depends on the predominant location and extent of gut involvement as well as the component of the gut neuromusculature affected.

AREAS COVERED

A comprehensive literature review was conducted using the PubMed and Medline databases to identify articles related to GI motility and functional disorders, published between 2016 and 2023. In this article, we highlight the current knowledge of molecular and genetic mechanisms underlying GI dysmotility, including disorders of gut-brain interaction, which involve both GI motor and sensory disturbance.

EXPERT OPINION

Although the pathophysiology and molecular mechanisms underlying many such disorders remain unclear, recent advances in the assessment of intestinal tissue samples, genetic testing with the application of 'omics' technologies and the use of animal models will provide better insights into disease pathogenesis as well as opportunities to improve therapy.

Dilated gut conditions: diagnosis and management

Dilatation of the gut occurs in response to either mechanical obstruction or aperistalsis. The hallmark features are symptoms of bowel obstruction with vomiting, constipation, abdominal pain and distension. This review will primarily deal with the non-mechanical causes of gut dilatation, both intestinal and colonic, and differentiate between acute and chronic presentations.

The mechanisms of nerve injury caused by viral infection in the occurrence of gastrointestinal motility disorder-related diseases

Gastrointestinal motility refers to the peristalsis and contractility of gastrointestinal muscles, including the force and frequency of gastrointestinal muscle contraction. Gastrointestinal motility maintains the normal digestive function of the human body and is a critical component of the physiological function of the digestive tract. At present, gastrointestinal motility disorder-related diseases are gradually affecting human production and life. In recent years, it has been consistently reported that the enteric nervous system has a coordinating and controlling role in gastrointestinal motility. Motility disorders are closely related to functional or anatomical changes in the gastrointestinal nervous system. At the same time, some viral infections, such as herpes simplex virus and varicella-zoster virus infections, can cause damage to the gastrointestinal nervous system. Therefore, this paper describes the mechanisms of viral infection in the gastrointestinal nervous system and the associated clinical manifestations. Studies have indicated that the means by which viruses can cause the infection of the enteric nervous system are various, including retrograde transport, hematogenous transmission and centrifugal transmission from the central nervous system. When viruses infect the enteric nervous system, they can cause clinical symptoms, such as abdominal pain, abdominal distension, early satiation, belching, diarrhea, and constipation, by recruiting macrophages, lymphocytes and neutrophils and regulating intestinal microbes. The findings of several case‒control studies suggest that viruses are the cause of some gastrointestinal motility disorders. It is concluded that one of the causes of gastrointestinal motility disorders is viral infection of the enteric nervous system. In such disorders, the relationships between viruses and nerves remain to be studied more deeply. Further studies are necessary to evaluate whether prophylactic antiviral therapy is feasible in gastrointestinal motility disorders.

Historical Cohort Study of Congenital Isolated Hypoganglionosis of the Intestine: Determining the Best Surgical Interventions

No standard diagnostic method or surgical treatment for congenital isolated hypoganglionosis (CIHG) has been established. This study aimed to analyze the clinical outcomes of patients with CIHG and identify the best surgical interventions provided thus far. Data on surgical interventions in 19 patients were collected between 1992 and 2020, including the type of enterostomy, type of revision, and length of the intestines. Ganglion cells in the myenteric plexus were enumerated using Hu C/D staining. The ratio of the length of the small intestine to its height was defined as the intestinal ratio (IR). The outcomes were assessed using the stoma output, growth parameters including the body mass index (BMI), and parenteral nutrition (PN) dependency. All patients required a diverting enterostomy. The IR ranged from 0.51 to 1.75 after multiple non-transplant surgeries. The stoma types were tube-stoma, end-stoma, Santulli-type, and Bishop-Koop (BK)-type. Patients with Santulli- or BK-type stomas had better BMIs and less PN dependency in terms of volume than those with end-stomas or tube-stomas. Two patients with BK-type stomas were off PN, and three who underwent an intestinal transplantation (Itx) achieved enteral autonomy. The management of CIHG involves a precise diagnosis using Hu C/D staining, neonatal enterostomy, and stoma revision using the adjusted IR and Itx if other treatments do not enable enteral autonomy.

ESPEN guideline on chronic intestinal failure in adults - Update 2023

BACKGROUND & AIMS

In 2016, ESPEN published the guideline for Chronic Intestinal Failure (CIF) in adults. An updated version of ESPEN guidelines on CIF due to benign disease in adults was devised in order to incorporate new evidence since the publication of the previous ESPEN guidelines.

METHODS

The grading system of the Scottish Intercollegiate Guidelines Network (SIGN) was used to grade the literature. Recommendations were graded according to the levels of evidence available as A (strong), B (conditional), 0 (weak) and Good practice points (GPP). The recommendations of the 2016 guideline (graded using the GRADE system) which were still valid, because no studies supporting an update were retrieved, were reworded and re-graded accordingly.

RESULTS

The recommendations of the 2016 guideline were reviewed, particularly focusing on definitions, and new chapters were included to devise recommendations on IF centers, chronic enterocutaneous fistulas, costs of IF, caring for CIF patients during pregnancy, transition of patients from pediatric to adult centers. The new guideline consist of 149 recommendations and 16 statements which were voted for consensus by ESPEN members, online in July 2022 and at conference during the annual Congress in September 2022. The Grade of recommendation is GPP for 96 (64.4%) of the recommendations, 0 for 29 (19.5%), B for 19 (12.7%), and A for only five (3.4%). The grade of consensus is "strong consensus" for 148 (99.3%) and "consensus" for one (0.7%) recommendation. The grade of consensus for the statements is "strong consensus" for 14 (87.5%) and "consensus" for two (12.5%).

CONCLUSIONS

It is confirmed that CIF management requires complex technologies, multidisciplinary and multiprofessional activity, and expertise to care for the underlying gastrointestinal disease and to provide HPN support. Most of the recommendations were graded as GPP, but almost all received a strong consensus.

Multi-disciplinary Insights from the First European Forum on Visceral Myopathy 2022 Meeting

Visceral myopathy is a rare, life-threatening disease linked to identified genetic mutations in 60% of cases. Mostly due to the dearth of knowledge regarding its pathogenesis, effective treatments are lacking. The disease is most commonly diagnosed in children with recurrent or persistent disabling episodes of functional intestinal obstruction, which can be life threatening, often requiring long-term parenteral or specialized enteral nutritional support. Although these interventions are undisputedly life-saving as they allow affected individuals to avoid malnutrition and related complications, they also seriously compromise their quality of life and can carry the risk of sepsis and thrombosis. Animal models for visceral myopathy, which could be crucial for advancing the scientific knowledge of this condition, are scarce. Clearly, a collaborative network is needed to develop research plans to clarify genotype-phenotype correlations and unravel molecular mechanisms to provide targeted therapeutic strategies. This paper represents a summary report of the first 'European Forum on Visceral Myopathy'. This forum was attended by an international interdisciplinary working group that met to better understand visceral myopathy and foster interaction among scientists actively involved in the field and clinicians who specialize in care of people with visceral myopathy.

Pediatric Intestinal Pseudo-Obstruction: An International Survey on Diagnostic and Management Strategies in the European Reference Network for Rare Inherited and Congenital Anomalies Intestinal Failure Teams

OBJECTIVES

Pediatric intestinal pseudo-obstruction (PIPO) management is based on nutritional, medical, and surgical care while available evidence is scarce. The aim of this study was to outline the current diagnostic and management strategies in intestinal failure (IF) teams of the European Reference Network for rare Inherited and Congenital Anomalies (ERNICA) and to compare these practices to the latest PIPO international guidelines.

METHODS

An online survey on institutional diagnostic and management strategies of PIPO was conducted among the ERNICA IF teams.

RESULTS

In total, 11 of 21 ERNICA IF centers from 8 countries participated. On average, 64% of teams had ≥6 and 36% had 1-5 PIPO patients under active follow-up. In total, 80 of 102 PIPO patients were parenteral nutrition (PN) dependent while each IF team had median 4 (range 0-19) PN dependent PIPO patients under follow-up. On average, each center received 1-2 new PIPO patients per year. Diagnostics mostly followed current guidelines while medical and surgical management strategies were diverse.

CONCLUSIONS

Numbers of PIPO patients are low and management strategies are diverse among ERNICA IF teams. To improve PIPO patient care, regional reference centers with specialized multidisciplinary IF teams and continuous collaboration across centers are needed.

Pharmacological and nutritional therapy of children and adults with chronic intestinal pseudo-obstruction

INTRODUCTION

Chronic intestinal pseudo-obstruction (CIPO) is a rare, heterogeneous and severe form of gastrointestinal dysmotility.

AREAS COVERED

Pertinent literature on pediatric and adult CIPO management has been assessed via PubMed, Scopus, and EMBASE from inception to June 2022. Prokinetics, aimed at restoring intestinal propulsion (e.g. orthopramides and substituted benzamides, acetyl cholinesterase inhibitors, serotonergic agents and others), have been poorly tested and the available data showed only partial efficacy. Moreover, some prokinetic agents (e.g. orthopramides and substituted benzamides) can cause major side effects. The CIPO-related small intestinal bacterial overgrowth requires treatment preferably via poorly absorbable antibiotics to avoid bacterial resistance. Apart from opioids, which worsen gut motility, analgesics should be considered to manage visceral pain, which might dominate the clinical manifestations. Nutritional support, via modified oral feeding, enteral or parenteral nutrition, is key to halt CIPO-related malnutrition.

EXPERT OPINION

There have been significant roadblocks preventing the development of CIPO treatment. Nonetheless, the considerable advancement in neurogastroenterology and pharmacological agents cast hopes to test the actual efficacy of new prokinetics via well-designed clinical trials. Adequate dietary strategies and supplementation remain of crucial importance. Taken together, novel pharmacological and nutritional options are expected to provide adequate treatments for these patients.

The North American Society for Pediatric Gastroenterology, Hepatology, and Nutrition Position on the Role of the Registered Dietitian Nutritionist in the Care of the Pediatric Patient With Chronic Gastrointestinal Diseases

The optimization of nutrition is essential for the growth and development of all children, including those with gastrointestinal (GI) conditions that can variably affect nutrient intake, absorption, or metabolism. Registered Dietitian Nutritionists (RDNs) are essential partners in delivering high quality care for pediatric GI disorders, but limited evidence is available to support the role of the RDN in the care of these patients. This position paper outlines the evidence supporting the role of the RDN in the management of chronic pediatric GI issues in both inpatient and outpatient settings. Gaps in the literature, opportunities for future research, and barriers to RDN access are discussed.

The Potential Role of Microorganisms on Enteric Nervous System Development and Disease

The enteric nervous system (ENS), the inherent nervous system of the gastrointestinal (GI) tract is a vast nervous system that controls key GI functions, including motility. It functions at a critical interface between the gut luminal contents, including the diverse population of microorganisms deemed the microbiota, as well as the autonomic and central nervous systems. Critical development of this axis of interaction, a key determinant of human health and disease, appears to occur most significantly during early life and childhood, from the pre-natal through to the post-natal period. These factors that enable the ENS to function as a master regulator also make it vulnerable to damage and, in turn, a number of GI motility disorders. Increasing attention is now being paid to the potential of disruption of the microbiota and pathogenic microorganisms in the potential aetiopathogeneis of GI motility disorders in children. This article explores the evidence regarding the relationship between the development and integrity of the ENS and the potential for such factors, notably dysbiosis and pathogenic bacteria, viruses and parasites, to impact upon them in early life.

Enteric Neuromyopathies: Highlights on Genetic Mechanisms Underlying Chronic Intestinal Pseudo-Obstruction

Severe gut motility disorders are characterized by the ineffective propulsion of intestinal contents. As a result, the patients develop disabling/distressful symptoms, such as nausea and vomiting along with altered bowel habits up to radiologically demonstrable intestinal sub-obstructive episodes. Chronic intestinal pseudo-obstruction (CIPO) is a typical clinical phenotype of severe gut dysmotility. This syndrome occurs due to changes altering the morpho-functional integrity of the intrinsic (enteric) innervation and extrinsic nerve supply (hence neuropathy), the interstitial cells of Cajal (ICC) (mesenchymopathy), and smooth muscle cells (myopathy). In the last years, several genes have been identified in different subsets of CIPO patients. The focus of this review is to cover the most recent update on enteric dysmotility related to CIPO, highlighting (a) forms with predominant underlying neuropathy, (b) forms with predominant myopathy, and (c) mitochondrial disorders with a clear gut dysfunction as part of their clinical phenotype. We will provide a thorough description of the genes that have been proven through recent evidence to cause neuro-(ICC)-myopathies leading to abnormal gut contractility patterns in CIPO. The discovery of susceptibility genes for this severe condition may pave the way for developing target therapies for enteric neuro-(ICC)-myopathies underlying CIPO and other forms of gut dysmotility.

Intra- and Inter-observer Agreement of High Resolution Antroduodenal Manometry in Pediatric Patients Among Single Center Experts

OBJECTIVES

Studies in adults have suggested that high-resolution technology increases the diagnostic yield of antroduodenal manometry (ADM). However, there is no study comparing high-resolution with low-resolution ADM recordings as well as comparing the 2 types of high-resolution display [conventional line plot (CLP) and pressure topographic plots (PTP)]. We hypothesized that high-resolution ADM is a superior diagnostic modality with higher inter-observer and intra-observer agreement compared with low-resolution recordings.

METHODS

Twenty-four anonymized ADM studies were blindly analyzed by 3 experienced pediatric neurogastroenterologists. All studies had been performed using a low-compliance water-perfused system with a 20-channels catheter. Data were displayed as CLP, as both high-resolution and low-resolution, and PTP in different sessions with at least 6-week interval. Accuracy was evaluated using previous established diagnosis and specific pre-prandial and post-prandial manometric patterns. Inter-observer and intra-observer agreements were calculated.

RESULTS

Analysis with high-resolution CLP revealed a substantial inter-observer agreement among the 3 observers regarding the diagnosis (Krippendorff's alpha: 0.832; average pairwise percentage agreement: 88.9%). Conversely, PTP and low-resolution CLP showed poor agreement for diagnoses (Krippendorff's alpha: 0.600; average pairwise percentage agreement: 75.3%; Krippendorff's alpha: 0.390; average pairwise percentage agreement: 60.2%, respectively). For the intra-observer agreement, Krippendorff's alpha ranges were 0.891-1 for CLP and 0.19393-0.34621 for PTP.

CONCLUSIONS

Our study demonstrated higher diagnostic accuracy for high-resolution ADM compared to the low-resolution recordings. However, although it is well established for other motility investigations, PTP is not yet reliable in assessing foregut motor patterns. Advanced and more sophisticated software are clearly required for analyzing PTP display.

Autosomal Recessive ACTG2-Related Visceral Myopathy in Brothers

Pediatric intestinal pseudo-obstruction (PIPO) is a heterogeneous condition characterized by impaired gastrointestinal propulsion, a broad clinical spectrum, and variable severity. Several molecular bases underlying primary PIPO have been identified, of which autosomal dominant ACTG2-related visceral myopathy is the most common in both familial or sporadic primary PIPO cases. We present a family with autosomal recessive ACTG2-related disease in which both parents have mild gastrointestinal symptoms and sons have severe PIPO and bladder dysfunction.

Methods

Clinical genome sequencing was performed on the patients and the mother. Immunohistochemistry was performed on intestinal tissue from the patients to show expression levels of the ACTG2.

Results

Genome sequencing identified a 6.8 kb 2p13.1 loss that includes the ACTG2 gene and a maternally inherited missense variant p.Val10Met in the ACTG2 gene.

Discussion

This case demonstrates that monoallelic hypomorphic ACTG2 variants may underly mild primary gastrointestinal symptoms, while biallelic mild variants can cause severe diseases. The Deletions of the noncoding ACTG2 exon can be an under-recognized cause of mild gastrointestinal symptoms unidentifiable by exome sequencing, explaining some instances of interfamilial variability with an apparent autosomal dominant inheritance. Genome sequencing is recommended as a genetic work-up for primary or idiopathic PIPO because of genetic heterogeneity.

Diagnostic utility of Bcl-2 immunohistochemical expression in pediatric functional bowel obstruction cases with ganglionated specimens

Background

Functional disturbances of the gastrointestinal tract are caused by a number of neurodysplastic conditions, including diseases that are rarer than Hirschsprung’s disease (HSCR), such as ganglion cell immaturity and intestinal neuronal dysplasia (IND). Bcl-2 shows positive immunoreactivity in degenerative and immature ganglion cells (IGCs). This work evaluates the implication of the immunohistochemical expression of Bcl-2 in cases of pediatric intestinal pseudo-obstruction (IPO) with ganglionated specimens.

This 2-year prospective observational study was conducted from January 2017 to December 2019 on all intestinal specimens for cases referred from a pediatric surgery department with clinical data suggesting IPO (abdominal distension > 3 months, intermittent bilious vomiting, no radiological evidence of the transitional zone of HSCR or evidence of mechanical obstruction). The exclusion criteria were patients with IPO related to myopathic disorders, aganglionic biopsies, and specimens with inadequate tissue blocks. The same number of intestinal specimens of cases without IPO was used as a control group. All specimens underwent a histologic examination of ganglion cells and nerve bundles and were also evaluated for Bcl-2 immunohistochemical expression.

Results

Twenty-one specimens were analyzed, including six colonic resection specimens and 15 intestinal biopsies taken by full-thickness transanal biopsy (n = 12) or incisional biopsy from inadequately functioning stomas (n = 3). The mean ± standard deviation age of the patient cohort was 22 ± 7.4 months (range, 19–153 months), and there were 13 (61.9%) male patients. Bcl-2 protein was strongly positive in 57.1% of the cases, weakly positive in 19%, and negative in 23.8% as well as in all 21 control specimens. A highly significant correlation was observed between Bcl-2 expression and ganglion cell number (P < 0.001), where all hyperganglionic specimens showed strong positivity compared with the hypoganglionic and adequately ganglionic specimens. A positive association was also found between Bcl-2 expression and IND compared with other disorders of dysganglionosis (P = 0.04) and post-HSCR cases (P = 0.002).

Conclusion

Bcl-2 immunohistochemistry is a valuable tool to diagnose allied disorders of HSCR through its expression in IGCs, which are difficult to identify by conventional hematoxylin and eosin staining.

Long‐term follow‐up for pediatric intestinal pseudo‐obstruction patients in China

BACKGROUND

Pediatric intestinal pseudo-obstruction (PIPO) is a heterogeneous and severe group of disorders with a high mortality rate. Patients with PIPO often develop malnutrition and need long-term nutrition support. This study aimed to determine the nutrition status, particularly micronutrients, during the long-term follow-up of patients with PIPO.

METHODS

Fifty-eight patients with PIPO were followed up for at least 6 months between January 2008 and December 2020 in our hospital. PIPO was diagnosed based on the European society for pediatric gastroenterology, hepatology, and nutrition consensus. Data on clinical characteristics, medical and surgical management, nutrition support, serum vitamins, and mineral concentrations were collected. The patients were divided into the early-onset PIPO (EO-PIPO; neonatal-onset) and late-onset PIPO (LO-PIPO; infant- or child-onset) groups.

RESULTS

The mean follow-up was 29.5 months (6-153 months). The overall survival rate was 63.8% (37 out of 58 participants) (EO-PIPO, 48.6% [17 out of 35 participants]; LO-PIPO, 87.0% [20 out of 23 participants]). Mortality in the EO-PIPO group was higher than in the LO-PIPO group (P = 0.002). Twenty-one patients died, of which 18 (85.7%) patients had EO-PIPO and 14 (66.7%) patients died under 1 year of age. Infection was the major cause of death. Severe malnutrition was observed at baseline and during follow-up in 25 (43.1%) and 6 (16.2%) patients, respectively. At baseline and during follow-up, the zinc deficiency rates were 29.6% and 26.3%, and those of vitamin D were 26.9% and 52.6%, respectively.

CONCLUSIONS

Zinc and vitamin D deficiencies are common in patients with PIPO during follow-up. Therefore, additional supplements should be recommended.

The long Filamin-A isoform is required for intestinal development and motility: implications for chronic intestinal pseudo-obstruction

Filamin A (FLNA) is a cytoplasmic actin binding protein, recently shown to be expressed as a long and short isoform. Mutations in FLNA are associated with a wide spectrum of disorders, including an X-linked form of chronic intestinal pseudo-obstruction (CIPO). However, the role of FLNA in intestinal development and function is largely unknown. In this study, we show that FLNA is expressed in the muscle layer of the small intestine from early human fetal stages. Expression of FLNA variants associated with CIPO, blocked expression of the long flna isoform and led to an overall reduction of RNA and protein levels. As a consequence, contractility of human intestinal smooth muscle cells was affected. Lastly, our transgenic zebrafish line showed that the flna long isoform is required for intestinal elongation and peristalsis. Histological analysis revealed structural and architectural changes in the intestinal smooth muscle of homozygous fish, likely triggered by the abnormal expression of intestinal smooth muscle markers. No defect in the localization or numbers of enteric neurons was observed. Taken together, our study demonstrates that the long FLNA isoform contributes to intestinal development and function. Since loss of the long FLNA isoform does not seem to affect the enteric nervous system, it likely results in a myopathic form of CIPO, bringing new insights to disease pathogenesis.

High-resolution ultrasound and speckle tracking: a non-invasive approach to assess in vivo gastrointestinal motility during development

Gastrointestinal motor activity has been extensively studied in adults; however, only few studies have investigated fetal motor skills. It is unknown when the gastrointestinal tract starts to contract during the embryonic period and how this function evolves during development. Here, we adapted a non-invasive high-resolution echography technique combined with speckle tracking analysis to examine the gastrointestinal tract motor activity dynamics during chick embryo development. We provided the first recordings of fetal gastrointestinal motility in living embryos without anesthesia. We found that, although gastrointestinal contractions appear very early during development, they become synchronized only at the end of the fetal period. To validate this approach, we used various pharmacological inhibitors and BAPX1 gene overexpression in vivo. We found that the enteric nervous system determines the onset of the synchronized contractions in the stomach. Moreover, alteration of smooth muscle fiber organization led to an impairment of this functional activity. Altogether, our findings show that non-invasive high-resolution echography and speckle tracking analysis allows visualization and quantification of gastrointestinal motility during development and highlight the progressive acquisition of functional and coordinated gastrointestinal motility before birth.

Transpyloric propagation and liquid gastric emptying in children with foregut dysmotility

BACKGROUND/OBJECTIVES

Gastric emptying (GE) requires precise antropyloroduodenal coordination for effective transpyloric flow, the mechanisms of which are still unclear. We aimed to correlate gastric antral function assessed by antroduodenal manometry (ADM) with GE scintigraphy (GES) for liquid feeds in children with suspected gastrointestinal dysmotility.

METHODS

Children who underwent both ADM and GES over a five-year period were reviewed. ADM tracings were re-analyzed to assess antral frequency, amplitude, and motility index (MI) pre-prandially and postprandially. Transpyloric propagation (TPP) was defined as antegrade propagated antral activity preceding duodenal phase III of the migrating motor complex (MMC). TPP was defined as "poor" if occurring in <50% of all presented duodenal phases III. For GES, regions of interest over the whole stomach, fundus, and antrum were drawn to calculate GE half-time (GE-T_1/2 ) and retention rate (RR) in each region at 1 and 2 h.

RESULTS

Forty-seven children (median age: 7.0 years) were included. Twenty-two had PIPO, 14 functional GI disorders, and 11 gastroparesis. Children with poor TPP had longer GE-T_1/2 (113.0 vs 66.5 min, p = 0.028), higher RR of the whole stomach and fundus at 1 h (79.5% vs 63.5%, p = 0.038; 60.0% vs 41.0%, p = 0.022, respectively) and 2 h (51.0% vs 10.5%, p = 0.005; 36.0% vs 6.5%, p = 0.004, respectively). The pre-prandial antral amplitude of contractions inversely correlated with GE-T_1/2 , RR of the whole stomach, and fundus at 2 h.

CONCLUSIONS

TPP during phase III of the MMC correlated with gastric emptying of liquid and its assessment on ADM might predict abnormalities in postprandial gastric function.

Smooth muscle motility disorder phenotypes: A systematic review of cases associated with seven pathogenic genes (ACTG2, MYH11, FLNA, MYLK, RAD21, MYL9 and LMOD1)

Smooth muscle disorders affecting both the intestine and the bladder have been known for a decade. However, the recent discovery of genes associated with these dysfunctions has led to the description of several clinical phenotypes. We performed a systematic review of all published cases involving seven genes with pathogenic variants, ACTG2, MYH11, FLNA, MYLK, RAD21, MYL9 and LMOD1, and included 28 articles describing 112 patients and 5 pregnancies terminated before birth. The most commonly described mutations involved ACTG2 (75/112, 67% of patients), MYH11 (14%) and FLNA (13%). Twenty-seven patients (28%) died at a median age of 14.5 months. Among the 76 patients for whom this information was available, 10 (13%) had isolated chronic intestinal pseudo-obstruction (CIPO), 17 (22%) had isolated megacystis, and 48 (63%) had combined CIPO and megacystis. The respective proportions of these phenotypes were 9%, 20% and 71% among the 56 patients with ACTG2 mutations, 20%, 20% and 60% among the 10 patients with MYH11 mutations and 50%, 50% and 0% among the 7 patients with FLNA mutations.

TFAP2B Haploinsufficiency Impacts Gastrointestinal Function and Leads to Pediatric Intestinal Pseudo-obstruction

Background: Pediatric Intestinal Pseudo-obstruction (PIPO) is a congenital enteric disorder characterized by severe gastrointestinal (GI) dysmotility, without mechanical obstruction. Although several genes have been described to cause this disease, most patients do not receive a genetic diagnosis. Here, we aim to identify the genetic cause of PIPO in a patient diagnosed with severe intestinal dysmotility shortly after birth.

Methods: Whole exome sequencing (WES) was performed in the patient and unaffected parents, in a diagnostic setting. After identification of the potential disease-causing variant, its functional consequences were determined in vitro and in vivo. For this, expression constructs with and without the causing variant, were overexpressed in HEK293 cells. To investigate the role of the candidate gene in GI development and function, a zebrafish model was generated where its expression was disrupted using CRISPR/Cas9 editing.

Results: WES analysis identified a de novo heterozygous deletion in TFAP2B (NM_003221.4:c.602-5_606delTCTAGTTCCA), classified as a variant of unknown significance. In vitro studies showed that this deletion affects RNA splicing and results in loss of exon 4, leading to the appearance of a premature stop codon and absence of TFAP2B protein. Disruption of tfap2b in zebrafish led to decreased enteric neuronal numbers and delayed transit time. However, no defects in neuronal differentiation were detected. tfap2b crispants also showed decreased levels of ednrbb mRNA, a downstream target of tfap2b.

Conclusion: We showed that TFAP2B haploinsufficiency leads to reduced neuronal numbers and GI dysmotility, suggesting for the first time, that this gene is involved in PIPO pathogenesis.

Paediatric intestinal pseudo-obstruction: a scoping review

Paediatric intestinal pseudo-obstruction (PIPO) encompasses a group of rare disorders in which patients present with the clinical features of bowel obstruction in the absence of mechanical occlusion. The management of PIPO presents a challenge as evidence remains limited on available medical and surgical therapy. Parenteral nutrition is often the mainstay of therapy. Long-term therapy may culminate in life-threatening complications including intestinal failure-related liver disease, central line thrombosis and sepsis. Intestinal transplantation remains the only definitive cure in PIPO but is a complex and resource-limited solution associated with its own morbidity and mortality. We conducted a scoping review to present a contemporary summary of the epidemiology, aetiology, pathophysiology, diagnosis, management and complications of PIPO.Conclusion: PIPO represents a rare disorder that is difficult to diagnose and challenging to treat, with significant morbitity and mortality. The only known cure is intestinal transplantation. What is Known: • Paediatric intestinal pseudo-obstruction is a rare, heterogeneous disorder that confers a high rate of morbidity and mortality • Complications of paediatric intestinal pseudo-obstruction include chronic pain, small intestine bacterial overgrowth and malrotation. Other complications can occur related to its management, such as line infections with parenteral nutrition or cardiac side effects of prokinetic medications What is New: • Progress in medical and surgical therapy in recent years has led to improved patient outcomes • Enteral autonomy has been reported in most patients at as early as 1 month post-transplantation.

Anaemia in Children Receiving Home Parenteral Nutrition: A Common Problem?

OBJECTIVES

Children receiving home parenteral nutrition (HPN) are at risk of iron deficiency anaemia. Our aim was to determine the incidence of iron deficiency anaemia in paediatric HPN and efficacy of each therapeutic approach.

METHODS

Retrospective data collection from children receiving HPN at a tertiary referral centre over a 12-month period (2015). Full blood count, and whenever available, ferritin and C-reactive protein were collected at least 3 times for each patient. Liver function tests were checked at the beginning and end of the study and number of blood transfusions/iron infusions recorded.

RESULTS

Forty-one HPN patients (61% girls; 51% motility disorder, 29% enteropathy, 20% short bowel syndrome) were identified. Eighty-three percent of children were anaemic at the beginning of the study with the number decreasing to 73% by the end. Iron deficiency anaemia was most commonly seen and treated with blood transfusion in 46% of cases and iron infusions in 29%. There was no statistical difference in the level of haemoglobin improvement between the 2 treatments (50% vs 33%, P  = 0.657) nor a significant difference in haemoglobin (g/L) level achieved. The results for both were, however, more favourable in the infusion group. Patients receiving transfusions had a significantly higher incidence of abnormal liver function compared with those who hadinfusions (93% vs 37%, P = 0.009).

CONCLUSIONS

Iron deficiency anaemia is common in children receiving HPN. A large proportion of patients still receive blood transfusions as first-line therapy but intravenous iron can be a suitable alternative. Treatment guidelines are required.