Established and Emerging Concepts in Hirschsprung’s-Associated Enterocolitis

16S rRNA Sequencing Reveals Alterations of Gut Bacteria in Hirschsprung-Associated Enterocolitis

Hirschsprung-associated enterocolitis (HAEC) stands as most common and serious complication of Hirschsprung's disease. Variations in the microbiota composition may account for the differences observed between HAEC and healthy individuals, offering crucial insights into the disease's pathogenesis. Here, we performed a study to changes in the gut microbiome using 16sRNA amplicon sequencing in a cohort of HAEC patients ( n  = 16) and healthy controls ( n  = 14). Our result revealed a significant disparity in beta diversity between the two groups. Following correction for false discovery rate, a rank-sum test at the genus level indicated a notable decrease in the relative abundance of Bifidobacterium , Lactobacillus , and Veillonella , whereas the Enterococcus genus exhibited a substantial increase in HAEC, a finding further supported by additional linear discriminant analysis effect size analysis. Functional analysis showed that putative transport and catabolism, digestive system, and metabolism of cofactors and vitamins were proved to be some abundant KOs (Kyoto Encyclopedia of Genes and Genomes [KEGG] orthologs) in healthy group, whereas infectious disease, membrane transport, and carbohydrate metabolism were the three KOs with the higher abundance in the HAEC group. Our data increased our insight into the HAEC, which may shed further light on HAEC pathogenesis. Our study firstly demonstrated the difference between fecal microbiota of HAEC patients and healthy individuals, which made a step forward in the understanding of the pathophysiology of HAEC.

The mediating role of metabolites between gut microbiome and Hirschsprung disease: a bidirectional two-step Mendelian randomization study

Background

Gut microbiome (GM) was observed to be associated with the incidence of Hirschsprung disease (HD). However, the effect and mechanism of GM in HD is still unclear. To investigate the relationship between GM and HD and the effect of metabolites as mediators, a bidirectional two-step Mendelian randomization (MR) study was conducted.

Methods

The study selected instrument variables (IVs) from summary-level genome-wide association studies (GWAS). The MiBioGen consortium provided the GWAS data for GM, while the GWAS data for metabolites and HD were obtained from the GWAS Catalog consortium. Two-sample MR analyses were performed to estimate bidirectional correlations between IVs associated with GM and HD. Then, genetic variants related to 1,400 metabolite traits were selected for further mediation analyses using the Product method.

Results

This study found that seven genus bacteria had a significant causal relationship with the incidence of HD but not vice versa. 27 metabolite traits were significantly correlated with HD. After combining the significant results, three significant GM-metabolites-HD lines have been identified. In the Peptococcus-Stearoyl sphingomyelin (d18:1/18:0)-HD line, the Stearoyl sphingomyelin (d18:1/18:0) levels showed a mediation proportion of 14.5%, while in the Peptococcus-lysine-HD line, the lysine levels had a mediation proportion of 12.9%. Additionally, in the Roseburia-X-21733-HD line, the X-21733 levels played a mediation proportion of 23.5%.

Conclusion

Our MR study indicates a protective effect of Peptococcus on HD risk that is partially mediated through serum levels of stearoyl sphingomyelin (d18:1/18:0) and lysine, and a risk effect of Roseburia on HD that is partially mediated by X-21733 levels. These findings could serve as novel biomarkers and therapeutic targets for HD.

Development of Prediction Model for Hirschsprung-Associated Enterocolitis (HAEC) in Postoperative Hirschsprung Patients

BACKGROUND

Despite identifying numerous risk factors for postoperative Hirschsprung-associated enterocolitis (HAEC), predicting individual risk remains challenging. This study aimed to develop a clinical prediction model for predicting the probability of postoperative HAEC within 5 years after surgery in Hirschsprung individuals.

METHODS

The study included all children with Hirschsprung disease who underwent definitive surgery at Chiang Mai University Hospital from 2006 to 2021. Concomitant anorectal abnormalities and incomplete data were excluded. A multivariable logistic regression analysis, adjusted for correlated data, was utilized to develop the prediction model.

RESULTS

Of the included 274 patients, 75 patients (27.4%) experienced postoperative HAEC within 5 years, totaling 121 episodes. Based on statistical and theoretical significance, eight parameters were utilized as predictors, which included male (OR1.23,95%CI:0.53-2.86), trisomy21(OR1.34,95%CI:0.21-8.45), weight at the time of surgery (OR0.86,95%CI:0.73-1.02), absence of exclusive breastfeeding (OR1.51,95%CI:0.65-3.51), length of the aganglionic segment (rectosigmoid (OR1.32,95%CI:0.48-3.62), long segment (OR41.39,95%CI:3.00-570.37), and total colonic aganglionosis (OR710.20,95%CI:23.55-21420.72)), preoperative stoma (OR1.72,95%CI:0.34-8.58), surgical approach (Duhamel (OR0.06,95%CI:0.01-0.81) and abdominal assisted trans anal endorectal pull-through (OR0.04,95%CI:0.002-0.65)), and early HAEC before two weeks following surgery (OR1.98,95%CI:0.67-5.82). The derived predictive model exhibited acceptable discriminative performance (AuROC:0.749,95%CI:0.679-0.816). Risk groups were categorized into low and high-risk, with positive likelihood ratios of 0.65 and 10.70, respectively. Recommendations for management and follow-up were generated based on these risk groups. An online application has been developed for calculating individual risk of postoperative HAEC and offering management suggestions with follow-up schedule: [https://w1.med.cmu.ac.th/surgery/personnel/pedsurgerycmu/#HAEC-Calculator].

CONCLUSIONS

This risk predictive model accurately estimates the probability of postoperative HAEC within 5 years after surgery in Hirschsprung patients. It facilitates risk stratification and provides personalized recommendations to parents for the prevention and early detection of postoperative HAEC.

LEVELS OF EVIDENCE

Level II Retrospective cohort study (Prognosis study).

Postoperative Hirschsprung's associated enterocolitis (HAEC): transition zone as putative histopathological predictive factor

AIMS

Hirschsprung's-associated enterocolitis (HAEC) is the most severe complication of Hirschsprung disease (HD), and its pathogenesis is still unknown. Length of transition zone (TZ) interposed between aganglionic and normal bowel has been poorly explored as predictor for postoperative HAEC (post-HAEC). This study aimed to identify potential predictive factors for post-HAEC, with a particular focus on histopathological findings.

METHODS

Data from Hirschsprung patients treated in a single Italian centre between 2010 and 2022 with a follow-up >6 months were collected. Thorough histopathological examination of the resected bowel was conducted, focusing on length of TZ and aganglionic bowel.The degree of inflammatory changes in ganglionic resected bowel was further obtained. Ultra-long HD, total colonic aganglionosis and ultra-short HD were excluded. Bivariate and multivariate regression analysis were performed.

RESULTS

Thirty-one patients were included; 5 experienced preoperative HAEC (pre-HAEC) and later post-HAEC (16.1%), further 10 patients developed post-HAEC (total post-HAEC 48.38%). Pre-HAEC-history and a TZ<2.25 cm correlated with an early development of post-HAEC. Multivariate analysis identified a TZ<2.25 cm as an independent post-HAEC predictive factor (p=0.0096). Inflammation within the ganglionic zone and a TZ<2.25 cm correlated with higher risk of post-HAEC (p=0.0074, 0.001, respectively). Severe post-HAEC more frequently occurred in patients with pre-HAEC (p=0.011), histological inflammation (p=0.0009) and short TZ (p=0.0015).

CONCLUSIONS

This study suggests that TZ<2.25 cm predicts the risk of post-HAEC. Preoperative clinical and histopathology inflammation may predispose to worst post-HAEC. Readily available histopathological findings might help identifying patients at higher risk for HAEC and implementing prevention strategies.

Hirschsprung's disease associated enterocolitis: A comprehensive review

Hirschsprung's disease (HSCR) is a congenital disorder characterized by failure of the neural crest cells to migrate and populate the distal bowel during gestation affecting different lengths of intestine leading to a distal functional obstruction. Surgical treatment is needed to correct HSCR once the diagnosis is confirmed by demonstrating the absence of ganglion cells or aganglionosis of the affected bowel segment. Hirschsprung's disease associated enterocolitis (HAEC) is an inflammatory complication associated with HSCR that can present either in the pre- or postoperative period and associated with increased morbidity and mortality. The pathogenesis of HAEC remains poorly understood, but intestinal dysmotility, dysbiosis and impaired mucosal defense and intestinal barrier function appear to play a significant role. There is no clear definition for HAEC, but the diagnosis is primarily clinical, and treatment is guided based on severity. Here, we aim to provide a comprehensive review of the clinical presentation, etiology, pathophysiology, and current therapeutic options for HAEC.

Evaluation and Management of Postsurgical Patient With Hirschsprung Disease Neurogastroenterology & Motility Committee: Position Paper of North American Society of Pediatric Gastroenterology, Hepatology, and Nutrition (NASPGHAN)

Children with Hirschsprung disease have postoperative long-term sequelae in defecation that contribute to morbidity and mortality and significantly impact their quality of life. Pediatric patients experience ongoing long-term defecation concerns, which can include fecal incontinence (FI) and postoperative obstructive symptoms, such as constipation and Hirschsprung-associated enterocolitis. The American Pediatric Surgical Association has developed guidelines for management of these postoperative obstructive symptoms and FI. However, the evaluation and management of patients with postoperative defecation problems varies among different pediatric gastroenterology centers. This position paper from the Neurogastroenterology & Motility Committee of the North American Society for Pediatric Gastroenterology, Hepatology, and Nutrition reviews the current evidence and provides suggestions for the evaluation and management of postoperative patients with Hirschsprung disease who present with persistent defecation problems.

Prognostic factors of postoperative Hirschsprung-associated enterocolitis: a cohort study

PURPOSE

To identify prognostic factors of postoperative Hirschsprung-associated enterocolitis (HAEC).

METHOD

A retrospective cohort study of Hirschsprung patients between 2006 and 2021 was conducted. Patients with anorectal malformation and non-definitive surgery were excluded. Associated factors for postoperative HAEC were reported with hazard ratio (HR) and 95% confidence interval (CI).

RESULTS

Forty-nine patients were excluded due to concurrent anorectal malformation and incomplete data. Of 274 patients, 75 patients (27.4%) had at least one episode of postoperative HAEC. There were 28 patients (37.3%) who had multi-episodes of HAEC. The total episodes of post-operative HAEC in this study were 121 episodes (36.8%). In multivariable survival analysis, significant factors associated with postoperative HAEC were the aganglionic level above sigmoid colon (HR = 3.47, p = 0.023, 95% CI 1.19-10.09), and total colonic aganglionosis (HR = 14.83, p = 0.004, 95% CI 2.33-94.40). The patients who experienced clinical enterocolitis before 2 weeks after surgery significantly developed more postoperative HAEC (HR = 5.32, p = 0.038, % CI 1.09-25.92). The incidence of postoperative HAEC was increase in patients with postoperative obstructive symptoms (48.0%). One patient died due to severe sepsis from postoperative HAEC, while three others required intensive care.

CONCLUSIONS

The long involvement of aganglionic segment and early postoperative HAEC was significantly associated with postoperative HAEC. Frequent follow-up, parental education, and early treatment are recommended in these individuals, particularly in the first year after surgery.

Risk factors for Hirschsprung-associated enterocolitis following Soave: a retrospective study over a decade

Background

Hirschsprung-associated enterocolitis (HAEC), one of the most significant causes of morbidity and mortality for patients with Hirschsprung disease (HSCR), can occur before and after radical surgery. This study aims to identify the risk factors for HAEC before and after Soave. 

Methods

A retrospective study of 145 patients with HSCR treated by transanal or combination with laparoscopic or laparotomy Soave procedure between January 2011 and June 2021 was performed. Data were retrieved from the medical records. HAEC was defined as the presence of clinical signs of bowel inflammation and requiring treatment with intravenous antibiotics and rectal irrigation for at least two days in the outpatient or inpatient department. Univariate analysis and multivariate regression models were used to identify risk factors for developing pre-and postoperative HAEC.

Results

The incidence of pre-and postoperative HAEC was 24.1% and 20.7%, respectively. More than 90% of the patients with the first episode of postoperative HAEC occurred within the first year after Soave. Long-segment aganglionosis was the independent risk factor for developing preoperative HAEC ([OR] 5.8, Cl 2.4–14.2, p < 0.001), while the history of preoperative HAEC was significantly associated with developing postoperative HAEC ([OR] 4.2, Cl 1.6–10.8, p = 0.003).

Conclusions

Long-segment aganglionosis was the independent risk factor for the development of preoperative HAEC, and the history of preoperative HAEC was strongly associated with developing HAEC after Soave.

Level of Evidence

Level III

A pilot study characterizing longitudinal changes in fecal microbiota of patients with Hirschsprung-associated enterocolitis

PURPOSE

Hirschsprung disease is a neurointestinal disease that occurs due to failure of enteric neural crest-derived cells to complete their rostrocaudal migration along the gut mesenchyme, resulting in aganglionosis along variable lengths of the distal bowel. Despite the effective surgery that removes the aganglionic segment, children with Hirschsprung disease remain at high risk for developing a potentially life-threatening enterocolitis (Hirschsprung-associated enterocolitis). Although the etiology of this enterocolitis remains poorly understood, several recent studies in both mouse models and in human subjects suggest potential involvement of gastrointestinal microbiota in the underlying pathogenesis of Hirschsprung-associated enterocolitis.

METHODS

We present the first study to exploit the Illumina MiSeq next-generation sequencing platform within a longitudinal framework focused on microbiomes of Hirschsprung-associated enterocolitis in five patients. We analyzed bacterial communities from fecal samples collected at different timepoints starting from active enterocolitis and progressing into remission.

RESULTS

We observed compositional differences between patients largely attributable to variability in age at the time of sample collection. Remission samples across patients exhibited compositional similarity, including enrichment of Blautia, while active enterocolitis samples showed substantial variability in composition.

CONCLUSIONS

Overall, our findings provide continued support for the role of GI microbiota in the pathogenesis of Hirschsprung-associated enterocolitis.

Identification and validation of the common pathogenesis and hub biomarkers in Hirschsprung disease complicated with Crohn’s disease

Background

Although increasing evidence has supported that Hirschsprung disease (HSCR) is the risk factor for children developing Crohn’s disease (CD), the common mechanism of its co-occurrence remains unknown. The purpose of this study is to further explore the underlying mechanism and biomarkers for the co-occurrence of HSCR and CD.

Methods

The Gene Expression Omnibus (GEO) database was used to obtain gene expression profiles for CD (GSE95095) and HSCR (GSE98502). Following the identification of the shared differentially expressed genes (DEGs) of CD and HSCR, functional annotation, protein–protein interaction (PPI) network creation, and module assembly were performed to discover hub genes. RT-qPCR was performed to validate the expression of the hub genes in HSCR samples. The receiver operating characteristic (ROC) curve was utilized to assess the accuracy of the hub genes as biomarkers in predicting CD in both the training dataset and test dataset.

Results

A total of 103 common DEGs (50 downregulated genes and 53 upregulated genes) were chosen for further investigation. The importance of chemokines and cytokines in these two disorders is highlighted by functional analysis. MCODE plug identified three important modules, which functionally enriched the immune system process. Finally, nine hub genes were identified using cytoHubba, including IL1B, IL10, CXCL10, ICAM1, EGR1, FCGR3A, S100A12, S100A9, and FPR1. The nine hub genes were mainly enriched in immune- and inflammation-related pathways. External data profiles and RT-qPCR confirmed the expression of the nine hub genes in HSCR and CD. ROC analysis revealed that the nine hub genes had a strong diagnostic value.

Conclusion

Our study reveals the common pathogenesis of HSCR and CD. These hub genes and diagnostic models may provide novel insight for the diagnosis and treatment of HSCR complicated with CD.

Mortality Prediction Score for Hirschsprung's Disease-Associated Enterocolitis: A Novel Mortality Prediction Model

INTRODUCTION

Enterocolitis associated with Hirschsprung's disease is a fatal and serious complication. Number of scoring systems are in vogue to grade the severity of Hirschsprung's disease associated with enterocolitis (HDAEC), but none of these scoring systems help predict mortality. Hence, we attempt to develop a mortality prediction model (MPM) for HDAEC.

MATERIALS AND METHODS

A retrospective analysis of all cases of HDAEC encountered was analyzed. We also used the parameters of Elhalaby et al. for data collection. A total number of 71 cases were analyzed with regard to mortality in relation to each parameter. Sensitivity and specificity were calculated by statistician, and based on these values, a scoring model was proposed. All those with predicted mortality were given score 2 and those who did not were given score 1.

RESULTS

A total score of more than 16 predicted mortality, a score of <10 predicted survival, and a score between 11 and 15 predicted survival with morbidity.

CONCLUSION

A MPM for HDAEC is being proposed.

A Novel Method for Identifying the Transition Zone in Long-Segment Hirschsprung Disease: Investigating the Muscle Unit to Ganglion Ratio

Hirschsprung disease (HSCR) is characterised by the absence of enteric ganglia along variable lengths of the distal bowel. Current gold standard treatment involves the surgical resection of the defective, aganglionic bowel. Clear and reliable distinction of the normoganglionated bowel from the transition zone is key for successful resection of the entire defective bowel, and the avoidance of subsequent postoperative complications. However, the intraoperative nature of the tissue analysis and the variability of patient samples, sample preparation, and operator objectivity, make reproducible identification of the transition zone difficult. Here, we have described a novel method for using muscle units as a distinctive landmark for quantifying the density of enteric ganglia in resection specimens from HSCR patients. We show that the muscle unit to ganglion ratio is greater in the transition zone when compared with the proximal, normoganglionated region for long-segment HSCR patients. Patients with short-segment HSCR were also investigated, however, the muscle unit to ganglion ratio was not significantly different in these patients. Immunohistochemical examination of individual ganglia showed that there were no differences in the proportions of either enteric neurons or glial cells through the different regions of the resected colon. In addition, we identified that the size of enteric ganglia was smaller for patients that went on to develop HSCR associated enterocolitis; although the density of ganglia, as determined by the muscle unit to ganglia ratio, was not different when compared with patients that had no further complications. This suggests that subtle changes in the enteric nervous system, even in the “normoganglionated” colon, could be involved in changes in immune function and subsequent bacterial dysbiosis.

Different Fecal Microbiota in Hirschsprung's Patients With and Without Associated Enterocolitis

Background and Objectives

Patients with Hirschsprung's disease are at risk of developing Hirschsprung-associated enterocolitis, especially in the first 2 years of life. The pathophysiology of this inflammatory disease remains unclear, and intestinal dysbiosis has been proposed in the last decade. The primary objective of this study was to evaluate in a large cohort if Hirschsprung-associated enterocolitis was associated with alterations of fecal bacterial composition compared with HD without enterocolitis in different age groups.

Methods

We analyzed the fecal microbiota structure of 103 Hirschsprung patients from 3 months to 16 years of age, all of whom had completed definitive surgery for rectosigmoid Hirschsprung. 16S rRNA gene sequencing allowed us to compare the microbiota composition between Hirschsprung's disease patients with (HAEC group) or without enterocolitis (HD group) in different age groups (0-2, 2-6, 6-12, and 12-16 years).

Results

Richness and diversity increased with age group but did not differ between HD and HAEC patients, irrespective of the age group. Relative abundance of Actinobacteria was lower in HAEC than in HD patients under 2 years of age (-66%, P = 0.045). Multivariate analysis by linear models (MaAsLin) considering sex, medications, birth mode, breast-feeding, and the Bristol stool scale, as well as surgery parameters, highlighted Flavonifractor plautii and Eggerthella lenta, as well as Ruminococcus gnavus group, as positively associated with Hirschsprung-associated enterocolitis in the 0-2 years age group.

Conclusion

Hirschsprung-associated enterocolitis was associated with features of intestinal dysbiosis in infants (0-2 years) but not in older patients. This could explain the highest rate of enterocolitis in this age group.

Clinical Trial Registration

https://clinicaltrials.gov/ct2/show/NCT02857205, MICROPRUNG, NCT02857205, 02/08/2016.

Management of Hirschsprung associated enterocolitis-How different are practice strategies? An international pediatric endosurgery group (IPEG) survey

INTRODUCTION

Hirschsprung's-associated enterocolitis (HAEC) is a common post-operative problem for patients with Hirschsprung disease (HSCR). However, treatment strategies remain variable among providers, institutions, and even nations. The purpose of this study was to identify differences in treatment patterns for HAEC.

METHODS

A questionnaire was distributed to members of the International Pediatric Endoscopic Group (IPEG) community that focused on HSCR and HAEC management strategies. Questionnaire responses were collected via the Research Electronic Data Capture (RedCap).

RESULTS

178 responses were obtained: 30% from North America, 20% South America, 20% Europe, 26% Asia, and 4% from Australia. 37% had a dedicated pediatric colorectal center. After diagnosis, 53% send patients home with irrigations, while 29% perform a primary PT before discharge; the type of PT varied between Soave (50%), Swenson (25%) and Duhamel (13%). Only 29 respondents (17%) stated their institution had guidelines for HAEC management; however, inpatient treatments were fairly consistent: 95% performed rectal irrigations, 93% obtained an abdominal radiograph, and 72% held feeds; 55% taught families irrigations before discharge. Utilization of Botulinum (BT) injections was mixed: 36% never utilized BT injections, 33% only used BT if irrigations were not tolerated, and 16% only injected BT for recurrent episodes. Preventative HAEC measures were also varied and included anal dilations (44%), prophylactic antibiotics (34%), probiotics (29%), and routine home irrigations (22%).

CONCLUSION

There is wide variation of care in managing enterocolitis episodes in patients with Hirschsprung disease. Further research leading to consensus guidelines and standardization practices can help improve the care for these patients.

LEVEL OF EVIDENCE

V TYPE OF STUDY: Treatment study/ survey.

The utilization of botulinum toxin for Hirschsprung disease

Patients with Hirschsprung disease (HD) can struggle with persistent obstructive symptoms even after a successful pull-through. These symptoms lead to stasis of stool and can result in Hirschsprung associated enterocolitis (HAEC). Recurrent episodes of HAEC warrant further workup; if there are no signs of mechanical obstruction or an aganglionic pull-through, the use of botulinum toxin injections to the internal anal sphincter has been utilized to relieve these symptoms. In this review, we describe the variations in botulinum toxin injection use and describe ongoing studies to prevent obstructive symptoms and Hirschsprung-associated enterocolitis (HAEC). Botulinum toxin injection utilization has been described for obstructive symptoms after HD pull-through, in the setting of active HAEC, and has been proposed to be part of the treatment algorithm for prevention of HAEC after pull-through. Dosing utilized for the injections, along with the complications, are also described. Prospective, multi-institutional trials are needed to identify the effectiveness of botulinum toxin injections in the outpatient/prophylactic setting as current data suggest some benefits in preventing future obstructive symptoms; however, other studies have conflicting results.

Feasibility of home and hospital colorectal irrigation with continuous tube placement for Hirschsprung’s disease in neonates and infants: a comparative retrospective study

Background

Since the length of the affected colon widely varies, the preoperative management of Hirschsprung’s disease varies from one hospital to another. For our cases in which the length of the aganglionic colon cannot be managed by enema, anal bougienage, or rectal irrigation, colorectal irrigation is used along with the placement of a transanal catheter for these patients as home or hospital management, until one-stage definitive surgery can be performed. No comparative studies have been conducted on the continuous tube placement method, and no study has utilized this method as home management. Thus, this study aimed to analyze the efficacy and feasibility of our proposed continuous tube placement management for patients with Hirschsprung’s disease in the hospital or even at home.

Results

We included 22 infants with Hirschsprung’s disease between 2008 and 2018. The patients were divided into two groups: those who were managed with enema, bougienage, and rectal irrigation (n = 6), and those who were managed with the placement of a continuous transanal tube and colorectal irrigation (n = 16). The group with continuous transanal tube placement was further divided into two groups: those who were preoperatively managed with a continuous anorectal tube at home (n = 7), and those at a hospital (n = 9). Preoperative demographic information and clinical details were retrospectively examined and compared between the two groups. Univariate analysis showed no significant differences in the backgrounds and clinical status between the enema, bougienage, and rectal irrigation group and the colorectal irrigation group. The patients in the home group were older and weighed more at the time of radical surgery than those in the hospital group (p = 0.0267, p = 0.0377, respectively). The total duration of hospitalization until radical surgery was significantly decreased in the home group (p = 0.0315).

Conclusions

The total duration of hospitalization was significantly reduced in patients undergoing home colorectal irrigation which was as effective as the conventional method, with no impact on the preoperative condition or postoperative outcomes. Hence, our home-based preoperative management for patients with Hirschsprung’s disease may be effective and potentially feasible for the management of patients with Hirschsprung’s disease.

Alterations of Gut Bacteria in Hirschsprung Disease and Hirschsprung-Associated Enterocolitis

Hirschsprung-associated enterocolitis (HAEC) is a common life-threatening complication of Hirschsprung disease (HSCR). It has been proposed that gut microbiota, which have an essential role in gut-homeostasis, are associated with HAEC. Recent studies demonstrated an increase in alpha diversity of fecal microbiota over time in HSCR mice and a decrease in diversity after surgery. In addition, clinical studies have reported a reduction in bacterial richness in HSCR children after surgery. Some studies revealed a difference in microbiota between the proximal ganglionic and distal aganglionic intestine and found a difference in bacterial character between fecal and colonic specimens. HAEC studies found an increase in Proteobacteria, especially Escherichia and Enterobacteriaceae, with a decrease in Firmicutes and Bifidobacterium in HAEC patients. However, the direction of alpha diversity in HAEC patients is still controversial. The self-comparison of microbiota in treatment periods suggested that probiotics might improve gut dysbiosis and decrease the frequency of enterocolitis, but some reported contradictory findings. This review comprehensively summarizes and discusses key findings from animal and clinical data of the distinct microbiome associated with HCSR and the association of gut dysbiosis with the development of HAEC. This information should be useful in the establishment of novel interventions to improve gut dysbiosis and prevent enterocolitis in HSCR patients.

Clinical characteristics and validation of diagnosis in individuals with Hirschsprung disease and inflammatory bowel disease

BACKGROUND/PURPOSE

Hirschsprung disease has previously been reported to be associated with inflammatory bowel disease (IBD). The aim was to clinically confirm the diagnosis and to describe characteristics among individuals with both conditions in a national populationbased cohort.

METHODS

Nationwide, population-based cohort study, including all individuals with a Hirschsprung disease diagnosis and an IBD diagnosis registered between 1964 and 2016, in which clinical data were collected from the medical records of 18 validated cases with both Hirschsprung disease and IBD. The medical record of each individual in the study cohort was reviewed for age at IBD diagnosis, type of aganglionosis, type of surgical treatment, subtype of IBD, and treatment for IBD.

RESULTS

Median age at follow up was 34 years (range 19-66), and 3 of 18 indivduals (17%) were females. Median age at first diagnosis of IBD was 21 years (range 10-46). Six patients had ulcerative colitis, ten had Crohn's disease and two had unclassified IBD. Most of the patients had pharmacological treatment for IBD and 5 (28%) individuals had surgical treatment.

CONCLUSION

Hirschsprung disease and IBD was clinically confirmed in 18 cases. Age at IBD onset and subtype of IBD is similar to IBD patients without Hirschsprung disease. Five individuals had undergone surgical treatment for IBD.

Comparison of Hirschsprung Disease Characteristics between Those with a History of Postoperative Enterocolitis and Those without: Results from the Pediatric Colorectal and Pelvic Learning Consortium

INTRODUCTION

 The current understanding of Hirschsprung-associated enterocolitis (HAEC) is based mainly on single-center, retrospective studies. The aims of this study are to determine risk factors for postoperative HAEC using the Pediatric Colorectal and Pelvic Learning Consortium (PCPLC) database.

MATERIALS AND METHODS

 We performed a multicenter, retrospective, case-control study of children with Hirschsprung disease (HD) who had undergone a pull-through procedure and were evaluated at a PCPLC member site between February 2017 and March 2020. The cohort with a history of postoperative HAEC was compared with that without postoperative episodes of HAEC to determine relevant associations with postoperative HAEC.

RESULTS

 One-hundred forty of 299 (46.8%) patients enrolled had a history of postoperative HAEC. Patients with a rectosigmoid transition zone had a lower association with postoperative HAEC as compared with those with a more proximal transition zone (odds ratio [OR]: 0.46, 95% confidence interval [CI]: 0.26, 0.84, p < 0.01). Private insurance was protective against postoperative HAEC on univariate analysis (OR: 0.62, 95% CI: 0.38, 0.99, p = 0.047), but not on multivariate analysis (OR: 0.62, 95% CI: 0.37, 1.04, p = 0.07). Preoperative HAEC was not associated with the development of postoperative HAEC.

CONCLUSION

 Patients with a rectosigmoid transition zone have less postoperative HAEC compared with patients with a more proximal transition zone. Multi-institutional collection of clinical information in patients with HD may allow for the identification of additional risk factors for HAEC and afford the opportunity to improve care.

The enteric nervous system in gastrointestinal disease etiology

A highly conserved but convoluted network of neurons and glial cells, the enteric nervous system (ENS), is positioned along the wall of the gut to coordinate digestive processes and gastrointestinal homeostasis. Because ENS components are in charge of the autonomous regulation of gut function, it is inevitable that their dysfunction is central to the pathophysiology and symptom generation of gastrointestinal disease. While for neurodevelopmental disorders such as Hirschsprung, ENS pathogenesis appears to be clear-cut, the role for impaired ENS activity in the etiology of other gastrointestinal disorders is less established and is often deemed secondary to other insults like intestinal inflammation. However, mounting experimental evidence in recent years indicates that gastrointestinal homeostasis hinges on multifaceted connections between the ENS, and other cellular networks such as the intestinal epithelium, the immune system, and the intestinal microbiome. Derangement of these interactions could underlie gastrointestinal disease onset and elicit variable degrees of abnormal gut function, pinpointing, perhaps unexpectedly, the ENS as a diligent participant in idiopathic but also in inflammatory and cancerous diseases of the gut. In this review, we discuss the latest evidence on the role of the ENS in the pathogenesis of enteric neuropathies, disorders of gut-brain interaction, inflammatory bowel diseases, and colorectal cancer.

Outcomes of preoperative anal dilatation for Hirschsprung disease

BACKGROUND/PURPOSE

There are some studies about the effect of postoperative anal dilatation on anastomotic stenosis and Hirschsprung-associated enterocolitis (HAEC), but we have not seen any report about preoperative anal dilatation. We hypothesized that preoperative anal dilatation could reduce the incidence of HAEC and facilitate the operation. We aim to compare the HAEC rates and postoperative complications between groups who either had or did not have anal dilatations (AD or NAD) prescribed before laparoscopic-assisted Soave pull-through procedures for Hirschsprung disease (HD); by this means, we will evaluate the benefit of dilatations before the surgery for HD.

METHODS

A retrospective review of children with HD operated in our hospital between 2014 and 2018 was performed. Those with 21 trisomy, total colonic aganglionosis, multiple stage procedures, serious congenital malformations, and lost to follow-up were excluded. Patients were divided into preoperative anal dilatation group (AD group) and no preoperative anal dilatation group (NAD group). Routine anal dilatation was performed in both groups from 2 weeks after laparoscopic-assisted Soave pull-through. The anal dilatation was carried out daily with metal anal dilators with size appropriate to the age of the child. The size of the anal dilators was increased by 1 mm every 2 weeks for at least 3 months. Demographic data, operation time, pre- and postoperative HAEC rates and postoperative obstructive symptoms between groups were compared. Significance was considered at P < 0.05.

RESULTS

There were 95 children (17 female and 78 male) included, 36 AD and 59 NAD. There was no significant difference in demographic data between the two groups. The incidence of HAEC between the groups was not different both preoperatively (14% vs. 24%, P = 0.298) and postoperatively (11% vs. 19%, P = 0.171). The postoperative obstructive symptoms rates were 19% versus 22% for the AD and NAD groups, respectively (P = 0.802). The operation time of group AD was significantly shorter than that of group NAD (P = 0.008). Preoperative anal dilatation could shorten the operation time in short and typical-segment (2.08 ± 0.39 vs. 2.67 ± 0.37, P = 0.009 and 3.05 ± 0.38 vs. 3.29 ± 0.46, P = 0.042), but has no significant effect on long-segment disease (3.85 ± 0.41 vs. 3.89 ± 0.30, P = 0.839).

CONCLUSION

We have not shown a reduced risk of developing HAEC or postoperative obstructive symptoms if anal dilatations are prescribed before surgery. However, it may decrease the difficulties of surgeries, so the operative time is shortened.

LEVEL OF EVIDENCE

Prognosis study.

LEVEL

II.

Predictive factors for the development of postoperative Hirschsprung-associated enterocolitis in children operated during infancy

PURPOSE

The risk factors for postoperative Hirschsprung-associated enterocolitis (HAEC) are still incompletely understood, especially age at which surgery is performed. Therefore, the aim of this study was to identify the risk factors for the development of postoperative HAEC in children operated during infancy.

METHODS

Thirty-five children who had undergone radical surgery for Hirschsprung disease (HD) during infancy were included in the study. They were divided into two groups; those who developed postoperative HAEC (HAEC, 14 patients) and those who did not (no HAEC, 21 patients). Their medical records were retrospectively reviewed for clinical details.

RESULTS

Developing postoperative HAEC was significantly associated with long-segment HD (p = 0.020) and the age at radical surgery (p = 0.0241). No other factors had a significant association with postoperative HAEC. In the patients who developed postoperative HAEC (n = 14), those with Trisomy 21 had significantly longer hospitalizations than those without. Patients with long-segment HD had a higher hospitalization rate than those with short-segment HD.

CONCLUSION

This study clearly showed that long-segment HD and older age at radical surgery are risk factors for developing postoperative HAEC.

Reducing Underdiagnosis of Hirschsprung-Associated Enterocolitis: A Novel Scoring System

BACKGROUND

Hirschsprung-Associated Enterocolitis (HAEC) is a life-threatening and difficult to diagnose complication of Hirschsprung Disease (HSCR). The goal of this study was to evaluate existing HAEC scoring systems and develop a new scoring system.

METHODS

Retrospective, multi-institutional data collection was performed. For each patient, all encounters were analyzed. Data included demographics, symptomatology, laboratory and radiographic findings, and treatments received. A "true" diagnosis of HAEC was defined as receipt of treatment with rectal irrigations, antibiotics, and bowel rest. The Pastor and Frykman scoring systems were evaluated for sensitivity/specificity and univariate and multivariate logistic regression performed to create a new scoring system.

RESULTS

Four centers worldwide provided data on 200 patients with 1450 encounters and 369 HAEC episodes. Fifty-seven percent of patients experienced one or more episodes of HAEC. Long-segment colonic disease was associated with a higher risk of HAEC on univariate analysis (OR 1.92, 95% CI 1.43-2.57). Six variables were significantly associated with HAEC on multivariate analysis. Using published diagnostic cutoffs, sensitivity/specificity for existing systems were found to be 38.2%/96% for Pastor's and 56.4%/86.9% for Frykman's score. A new scoring system with a sensitivity/specificity of 67.8%/87.9% was created by stepwise multivariate analysis. The new score outperformed the existing scores by decreasing underdiagnosis in this patient cohort.

CONCLUSIONS

Existing scoring systems perform poorly in identifying episodes of HAEC, resulting in significant underdiagnosis. The proposed scoring system may be better at identifying those underdiagnosed in the clinical setting. Head-to-head comparison of HAEC scoring systems using prospective data collection may be beneficial to achieve standardization in the field.

Inpatient management of Hirschsprung's associated enterocolitis treatment: the benefits of standardized care

INTRODUCTION

Patients with Hirschsprung's disease (HSCR) remain at risk of developing Hirschsprung-associated enterocolitis (HAEC) after surgical intervention. As inpatient management remains variable, our institution implemented an algorithm directed at standardizing treatment practices. This study aimed to compare the outcomes of patients pre- and post-algorithm.

METHODS

A retrospective review of patients admitted for HAEC was performed; January 2017-June 2018 encompassed the pre-implementation period, and October 2018-October 2019 was the post-implementation period. Demographics and outcomes were compared between the two groups.

RESULTS

Sixty-two episodes of HAEC occurred in 27 patients during the entire study period. Sixteen patients (59%) had more than one episode. The most common levels of the transition zone were the rectosigmoid (50%) and descending colon (27%). Following algorithm implementation, the median length of stay (2 vs. 7 days, p < 0.001), TPN duration (0 vs. 5.5 days, p < 0.001), and days to full enteral diet (6 days vs. 2 days, p < 0.001) decreased significantly. Readmission rates for recurrent enterocolitis were similar pre- and post-algorithm implementation.

CONCLUSION

The use of a standardized algorithm significantly decreases the length of stay and duration of intravenous antibiotic administration without increasing readmission rates, while still providing appropriate treatment for HAEC.

LEVEL OF EVIDENCE

III level.

TYPE OF STUDY

Retrospective comparative study.

Postoperative enterocolitis assessment using two different cut-off values in the HAEC score in Hirschsprung patients undergoing Duhamel and Soave pull-through

Background

Hirschsprung-associated enterocolitis (HAEC) is the most severe and potentially lethal complication of Hirschsprung disease (HSCR) which might occur following definitive surgery. Our objectives were: 1) to compare the incidence of HAEC after Duhamel and Soave procedures using different cut-off values of the HAEC scoring method; and 2) to associate them with the risk factors, including sex, aganglionosis type, mothers’ age at childbirth, gestational age, and mothers’ educational level.

Methods

Medical records of patients with HSCR who underwent Soave and Duhamel procedures in our institution, Indonesia (January 2012 – December 2016) were reviewed retrospectively. Two cut-off values of the HAEC scoring system (i.e., ≥10 and ≥ 4) were utilized.

Results

Eighty-three patients with HSCR were recruited in this study (Soave: 37 males and 7 females vs. Duhamel: 28 males and 11 females; p = 0.18). The incidence of HAEC after surgery was 14/83 (16.9%) and 38/83 (45.8%) for cut-off values of ≥10 and ≥ 4, respectively (p = 0.00012), and tended to have an association with sex (p = 0.09). Although it was not statistically significant (p = 0.07), the frequency of HAEC after Soave procedure tended to be higher in patients with their mother’s age of ≤35 years at childbirth than those with their mother’s age of > 35 years (OR = 7.9; 95% CI = 0.9–72.1). Multivariate analysis indicated none of the risk factors were associated with the frequency of HAEC after definitive surgery.

Conclusions

The lower cut-off value of ≥4 might increase the possibility to diagnose HAEC, particularly the mild cases. The incidence of HAEC after definitive surgery was not associated with any risk factors in our cohort patients. Further multicenter studies with a larger sample size are necessary to confirm our findings.

Increased protease activated receptors in the colon of patients with Hirschsprung's disease

PURPOSE

The pathophysiology of Hirschsprung's associated enterocolitis (HAEC) is not understood. Abnormal intestinal motility and altered intestinal epithelial barrier function have been suggested to play a key role in the causation of HAEC. Protease-activated receptors (PARs) 1 and 2, have been implicated in inflammatory reactions, intestinal permeability and modulation of motility in the gut.

METHODS

We investigated PAR-1 and PAR-2 protein expression in aganglionic and ganglionic regions of patients with Hirschsprung's Disease (HSCR) (n = 10) versus normal control colon (n = 10). Protein distribution was assessed by using immunofluorescence and confocal microscopy. Gene and protein expression were quantified using quantitative real-time polymerase chain reaction (qPCR), western blot analysis, and densitometry.

RESULTS

qPCR and Western blot analysis revealed that PAR-1 and PAR-2 expression was significantly increased in ganglionic and aganglionic bowel in HSCR compared to controls (p < 0.003). Confocal microscopy revealed strong PAR-1 and PAR-2 expression in smooth muscles, interstitial cells of Cajal (ICCs), platelet-derived growth factor-alpha receptor-positive (PDGFRα⁺) cells, enteric neurons and epithelium in the ganglionic and aganglionic bowel compared to controls.

CONCLUSION

Increased PAR-1 and PAR-2 expression in the colon of patients with HSCR suggests that excessive local release of PAR activating proteases may trigger inflammatory responses leading to HAEC.

37/67-laminin receptor facilitates neural crest cell migration during enteric nervous system development

Enteric nervous system (ENS) development is governed by interactions between neural crest cells (NCC) and the extracellular matrix (ECM). Hirschsprung disease (HSCR) results from incomplete NCC migration and failure to form an appropriate ENS. Prior studies implicate abnormal ECM in NCC migration failure. We performed a comparative microarray of the embryonic distal hindgut of wild-type and EdnrB^NCC-/- mice that model HSCR and identified laminin-β1 as upregulated in EdnrB^NCC-/- colon. We identified decreased expression of 37/67 kDa laminin receptor (LAMR), which binds laminin-β1, in human HSCR myenteric plexus and EdnrB^NCC-/- NCC. Using a combination of in vitro gut slice cultures and ex vivo organ cultures, we determined the mechanistic role of LAMR in NCC migration. We found that enteric NCC express LAMR, which is downregulated in human and murine HSCR. Binding of LAMR by the laminin-β1 analog YIGSR promotes NCC migration. Silencing of LAMR abrogated these effects. Finally, applying YIGSR to E13.5 EdnrB^NCC-/- colon explants resulted in 80%-100% colonization of the hindgut. This study adds LAMR to the large list of receptors through which NCC interact with their environment during ENS development. These results should be used to inform ongoing integrative, regenerative medicine approaches to HSCR.

Innate and Adaptive Immunity Linked to Recognition of Antigens Shared by Neural Crest-Derived Tumors

In the adult, many embryologic processes can be co-opted by during cancer progression. The mechanisms of divisions, migration, and the ability to escape immunity recognition linked to specific embryo antigens are also expressed by malignant cells. In particular, cells derived from neural crests (NC) contribute to the development of multiple cell types including melanocytes, craniofacial cartilage, glia, neurons, peripheral and enteric nervous systems, and the adrenal medulla. This plastic performance is due to an accurate program of gene expression orchestrated with cellular/extracellular signals finalized to regulate long-distance migration, proliferation, differentiation, apoptosis, and survival. During neurulation, prior to initiating their migration, NC cells must undergo an epithelial–mesenchymal transition (EMT) in which they alter their actin cytoskeleton, lose their cell–cell junctions, apicobasal polarity, and acquire a motile phenotype. Similarly, during the development of the tumors derived from neural crests, comprising a heterogeneous group of neoplasms (Neural crest-derived tumors (NCDTs)), a group of genes responsible for the EMT pathway is activated. Here, retracing the molecular pathways performed by pluripotent cells at the boundary between neural and non-neural ectoderm in relation to the natural history of NCDT, points of contact or interposition are highlighted to better explain the intricate interplay between cancer cells and the innate and adaptive immune response.

Comparison of pre-operative Hirschsprung-associated enterocolitis using classical criteria and Delphi method: A diagnostic study

Background

Hirschsprung-associated enterocolitis (HAEC) is the most common complication of Hirschsprung disease (HSCR) that may happen pre-operatively. Several methods have been reported to determine HAEC. Because the diagnosis of pre-operative HAEC might change the surgical plan, we aimed to determine the accuracy of the classical criteria for diagnosis of pre-operative HAEC and using the Delphi method as a gold standard.

Methods

Medical records of HSCR children who were admitted to our hospital from January 2009 to December 2015 were retrospectively analyzed.

Results

Ninety-six subjects were involved in this study, consisting of 74 males and 22 females. The most common findings of the Delphi score were abdominal distension (100%) and dilated loops of bowel (100%), followed by leucocytosis (78.6%), lethargy (71.4%), cutoff sign in rectosigmoid with absence of distal air (71.4%), and shift to left (71.4%). The frequency of pre-operative HAEC was 4.2% and 14.6% using the classical criteria and Delphi method, respectively (p = 0.016). The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy rates of the classical criteria for diagnosis of pre-operative HAEC were 14.3% (95% CI: 1.8-42.8%), 97.6% (95% CI: 91.5-99.7%), 50% (95% CI: 13.3-86.7%), 87% (95% CI: 84.3-89.2), and 85.4% (95% CI: 76.7-91.8%), respectively.

Conclusions

The frequency of pre-operative HAEC is low in our hospital. The accuracy of the classical criteria is considered relatively moderate for diagnosis of pre-operative HAEC.

Postoperative Pullthrough Obstruction in Hirschsprung Disease: Etiologies and Diagnosis

Some patients continue to have obstructive symptoms and/or incontinence after pullthrough surgery for Hirschsprung disease. Incontinence can be due to injury to the anal sphincter and/or dentate line, abnormal colonic motility (nonretentive), or a chronic large stool burden (retentive). A diagnostic algorithm based on clinical and pathological evaluations can be applied to distinguish potential etiologies for obstructive symptoms, which segregate into anatomic (mechanical or histopathological) or physiologic subgroups. Valuable clinical information may be obtained by anorectal examination under anesthesia, radiographic studies, and anorectal or colonic manometry. In addition, histopathological review of a patient's original resection specimen(s) as well as postoperative biopsies of the neorectum usually are an important component of the diagnostic workup. Goals for the surgical pathologist are to exclude incomplete resection of the aganglionic segment or transition zone and to identify other neuromuscular pathology that might explain the patient's dysmotility. Diagnoses established from a combination of clinical and pathological data dramatically alter management strategies. In rare instances, reoperative pullthrough surgery is required, in which case the pathologist must be aware of histopathological features specific to redo pullthrough resection specimens.

Diagnosis of Hirschsprung Disease

Diagnosis or exclusion of Hirschsprung disease (HSCR) is a frequent exercise in any pediatric hospital. Although HSCR may present at different ages and with varied clinical findings, the most common presentation is a neonate with severe constipation or signs of intestinal obstruction. A variety of diagnostic tests including contrast enema and anorectal manometry may be used as diagnostic screens, but diagnosis ultimately rests upon histopathological evaluation of a rectal biopsy. For the experienced pathologist, conventional hematoxylin-and-eosin-stained sections often suffice to exclude HSCR or establish the diagnosis. However, ancillary diagnostic tests such as acetylcholinesterase histochemistry or calretinin immunohistochemistry are complementary and extremely helpful in some cases. In this Perspectives article, we review the clinical and pathological features of HSCR, highlight those that are found in most patients, and discuss how to address particularly challenging aspects of the diagnostic workup.

SCGN deficiency results in colitis susceptibility

Inflammatory bowel disease (IBD) affects 1.5–3.0 million people in the United States. IBD is genetically determined and many common risk alleles have been identified. Yet, a large proportion of genetic predisposition remains unexplained. In this study, we report the identification of an ultra rare missense variant (NM_006998.3:c.230G > A;p.Arg77His) in the SCGN gene causing Mendelian early-onset ulcerative colitis. SCGN encodes a calcium sensor that is exclusively expressed in neuroendocrine lineages, including enteroendocrine cells and gut neurons. SCGN interacts with the SNARE complex, which is required for vesicle fusion with the plasma membrane. We show that the SCGN mutation identified impacted the localization of the SNARE complex partner, SNAP25, leading to impaired hormone release. Finally, we show that mouse models of Scgn deficiency recapitulate impaired hormone release and susceptibility to DSS-induced colitis. Altogether, these studies demonstrate that functional deficiency in SCGN can result in intestinal inflammation and implicates the neuroendocrine cellular compartment in IBD.

Hirschsprung Disease: The Rise of Structured Transition and Long-term Care

Hirschsprung disease, like most surgically correctable congenital anomalies, is now survivable well into adulthood. Patients are, therefore, presenting later in life with problems that were previously infrequently encountered by colorectal surgeons or gastroenterologists. The goals of our review are to describe the current state of care transition for this patient population, identify the specific needs for these patients, and propose guidelines which could inform a future model of transition from the pediatric to adult setting. This is a review of the current state of care transition and long-term outcomes for patients with Hirschsprung disease. Although these patients report a generally good quality of life, the majority suffer from some degree of lifelong gastrointestinal complication, regardless of the type of operative repair. A more formalized transition of care will provide a guide for pediatric surgeons and patients, alleviate colorectal surgeon and gastroenterologist concerns, and provide better long-term care for these patients.

Altered expression of caveolin-1 in the colon of patients with Hirschsprung's disease

BACKGROUND/PURPOSE

The pathogenesis of Hirschsprung's disease-associated enterocolitis (HAEC) is unclear. Caveolin-1 (Cav-1) regulates the functions of different nitric oxide synthase (NOS) isoforms, which play critical roles in inflammation and intestinal epithelial barrier function. We designed this study to investigate the hypothesis that Cav-1 expression is altered in the bowel of patients with Hirschsprung's disease (HSCR).

METHODS

HSCR tissue specimens (n = 10) were collected at the time of pull-through surgery and control samples were obtained at the time of colostomy closure in patients with imperforate anus (n = 10). qRT-PCR analysis was undertaken to quantify Cav-1 gene expression, and Western blot analysis was undertaken to determine Cav-1 protein quantification. Immunolabelling of Cav-1 proteins was visualized using confocal microscopy.

RESULTS

qRT-PCR and Western blot analysis revealed that Cav-1 was significantly downregulated in the aganglionic and ganglionic colon of patients with HSCR compared to controls (p < 0.01). Confocal microscopy revealed a markedly decreased expression of Cav-1 in colonic epithelium of aganglionic and ganglionic bowel of patients with HSCR compared to controls.

CONCLUSION

To our knowledge, this is the first report of significantly decreased Cav-1 expression in patients with HSCR. Decreased expression of Cav-1 in the bowel of HSCR may increase susceptibility to HAEC in HSCR.

Inflammatory Bowel Disease Serological Immune Markers Anti-Saccharomyces cerevisiae Mannan Antibodies and Outer Membrane Porin C are Potential Biomarkers for Hirschsprung-associated Enterocolitis

OBJECTIVE

Hirschsprung-associated enterocolitis (HAEC) is the most frequent complication in Hirschsprung disease (HSCR) patients. Currently HAEC is diagnosed clinically, leaving uncertainty in the diagnosis thereby potentially leading to over- or undertreatment of patients. The aim of this study was to identify immune biomarkers to aid in the diagnosis of HAEC.

METHODS

From 2012 to 2017, 43 children with HSCR enrolled in a multicenter study, underwent retrospective evaluation of their medical records, and questionnaire-directed parent interviews. HAEC status was determined using HAEC score with cutoff ≥4. Plasma was collected and analyzed by ELISA for the inflammatory bowel disease-associated antibodies: anti-Saccharomyces cerevisiae mannan antibodies (ASCA), outer membrane porin C (OmpC), CBir1, antineutrophil cytoplasmic antibodies. Data were analyzed using t test, univariate, multivariable, and binomial regression models.

RESULTS

Eighteen patients had at least 1 episode of HAEC, 25 had no history of HAEC. The HAEC and NO HAEC groups had similar median ages (3 years) and family histories of HSCR. The HAEC group showed markedly elevated ASCA IgA and OmpC antibody levels compared with the NO HAEC group, whereas CBir1 and antineutrophil cytoplasmic antibodies were similar between the groups. Both univariate and multivariable analysis revealed higher OmpC antibody levels associated with HAEC (odds ratio 1.39, confidence interval 1-1.92, P = 0.048), whereas univariate analysis identified a trend toward elevated IgA and immunoglobulin G ASCA levels with HAEC.

CONCLUSIONS

We identified elevated OmpC and ASCA serum antibody levels in HAEC patients, and that increased OmpC antibody levels correlated with HAEC occurrence, suggesting HAEC and Crohn disease share gut microbial-host immune responses. These antibodies may serve as potential biomarkers for HAEC, although prospective study with larger sample size is needed.

Enterocolitis in a Child With Hirschsprung Disease

Hirschsprung disease is a congenital abnormality that can be surgically corrected. However, Hirschsprung-associated enterocolitis can be a life-threatening sequela. Very little has been published in the emergency medicine literature about the risk of enterocolitis and shock in patients with a history of Hirschsprung disease. We describe the case of a 6-month-old male infant with a history of multiple surgeries for Hirschsprung disease who presented to the emergency department with a seemingly benign viral gastrointestinal illness. His stable condition led him to be discharged. However, 4 days later, he returned to the emergency department with severe diarrhea and was subsequently admitted to the pediatric intensive care unit for the management of enterocolitis and shock. With this case report, we aim to raise emergency physicians' awareness of the serious and possibly fatal complications of Hirschsprung disease. We argue that this single element of a patient's medical history can alter the management of seemingly simple viral gastrointestinal illnesses; rather than be discharged, such a patient requires surgical consultation and possibly admission for close monitoring and treatment.

Factors influencing the incidence of Hirschsprung associated enterocolitis (HAEC)

PURPOSE

This study aims to characterize risk factors for Hirschsprung-associated enterocolitis (HAEC). We hypothesize that earlier pull-through surgery is associated with lower risks of developing postoperative HAEC.

METHODS

A comparative study of 171 Hirschsprung patients treated from 1990 to 2017 was performed. Patients without HAEC were compared to patients with preoperative and/or postoperative HAEC. Results are presented as median [IQR] or frequency (%). Pearson's χ² test and Wilcoxon rank sum test were performed with a significance level at p < 0.05. Multivariable logistic regression analysis was used to adjust for potential confounders. A subanalysis was done to evaluate laparoscopic, laparotomy, and transanal surgeries.

RESULTS

Risk of developing preoperative HAEC was significantly associated with congenital malformations (OR 2.63 [1.11, 6.24]; p = 0.02). Birth weight was lower in patients with preoperative HAEC (OR 0.48 [95% CI 0.25, 0.93]; p = 0.03). On regression analysis, intestinal obstruction after surgery was significantly associated with postoperative HAEC (OR 8.2 [3.18, 21.13]; p < 0.0001). Patients with earlier pull-through surgery did not have a lower risk of developing postoperative HAEC.

CONCLUSIONS

Timing of surgery does not seem to be associated with a higher risk of developing pre- and postoperative HAEC. Predisposing factors for preoperative HAEC included associated malformations and lower birth weight, whereas intestinal obstruction was found to be associated with postoperative HAEC.

TYPE OF STUDY

Treatment study.

LEVEL OF EVIDENCE

Level III.

B-lymphocyte-intrinsic and -extrinsic defects in secretory immunoglobulin A production in the neural crest-conditional deletion of endothelin receptor B model of Hirschsprung-associated enterocolitis

Hirschsprung disease (HSCR) is a common cause of intestinal obstruction in the newborn. Hirschsprung-associated enterocolitis (HAEC) is a significant and life-threatening complication of HSCR, affecting up to 60% of patients. Animal models of endothelin receptor B (EdnrB) mutation reliably model human HSCR and HAEC. We previously demonstrated intestinal dysbiosis and a gut-specific deficiency of B-lymphocyte-produced secretory IgA (sIgA), the primary effector molecule of mucosal immunity, in mice with homozygous neural crest cell-conditional deletion of EdnrB (EdnrB^NCC-/-). To determine mechanisms for sIgA deficiency, we examined intrinsic and extrinsic aspects of B-lymphocyte development and function. Expression of the endothelin axis components [endothelin-1 (ET-1), endothelin-3 (ET-3), endothelin receptor A (EdnrA), EdnrB] were determined over a developmental time course. B-lymphocyte survival and Ig production were assayed in vitro. Polymeric Ig receptor (pIgR)-mediated IgA transport into the intestinal lumen was interrogated. We found endothelin axis component (EdnrA, EdnrB, ET-1, ET-3) expression in developing extramedullary hematopoietic organs and that some splenic B lymphocytes express EdnrB. Splenic B lymphocytes from EdnrB^NCC-/- mice showed no intrinsic defect in survival vs. wild-type (WT) B lymphocytes. In vitro stimulation of splenic B lymphocytes demonstrated decreased IgA, IgG, and IgM production in EdnrB^NCC-/- vs. WT mice. Additionally, small intestinal pIgR was decreased ∼50% in EdnrB^NCC-/- mice. These results suggest an intrinsic B-lymphocyte defect in antibody production as well as an extrinsic defect in IgA transport in the EdnrB^NCC-/- model of HAEC. Our results are consistent with human HAEC observations of decreased luminal sIgA and mouse models of other inflammatory bowel diseases, in which decreased pIgR is seen in concert with a dysregulated microbiota. Finally, our results suggest targeting the dysbiotic microbiome and pIgR-mediated sIgA transport as potential therapeutic approaches in prevention and treatment of HAEC.-Medrano, G., Cailleux, F., Guan, P., Kuruvilla, K., Barlow-Anacker, A. J., Gosain, A. B-lymphocyte-intrinsic and -extrinsic defects in secretory immunoglobulinA production in the neural crest-conditional deletion of endothelin receptor B model of Hirschsprung-associated enterocolitis.

Muscularis macrophage development in the absence of an enteric nervous system

The nervous system of the bowel regulates the inflammatory phenotype of tissue resident muscularis macrophages (MM), and in adult mice, enteric neurons are the main local source of colony stimulating factor 1 (CSF1), a protein required for MM survival. Surprisingly, we find that during development MM colonize the bowel before enteric neurons. This calls into question the requirement for neuron-derived CSF1 for MM colonization of the bowel. To determine if intestinal innervation is required for MM development, we analyzed MM of neonatal Ret^-/- (Ret KO) mice that have no enteric nervous system in small bowel or colon. We found normal numbers of well-patterned MM in Ret KO bowel. Similarly, the abundance and distribution of MM in aganglionic human colon obtained from Hirschsprung disease patients was normal. We also identify endothelial cells and interstitial cells of Cajal as the main sources of CSF1 in the developing bowel. Additionally, MM from neonatal Ret KOs do not differ from controls in baseline activation status or cytokine-production in response to lipopolysaccharide. Unexpectedly, these data demonstrate that the enteric nervous system is dispensable for MM colonization and patterning in the bowel, and suggest that modulatory interactions between MM and the bowel nervous system are established postnatally.

Bacterial Microbiome Dynamics in Post Pull-Through Hirschsprung-Associated Enterocolitis (HAEC): An Experimental Study Employing the Endothelin Receptor B-Null Mouse Model

PURPOSE

Hirschsprung-associated enterocolitis (HAEC) is the most frequent potentially life-threatening complication in children with Hirschsprung disease (HSCR) even after definitive corrective surgery. Mounting evidence suggests that intestinal microbiota likely contribute to the etiology of enterocolitis, so the aim of this study was to use a mouse model of post pull-through HAEC to compare the fecal bacterial communities of animals which developed HAEC to those free of enterocolitis.

METHODS

Ten Ednrb -/- and 8wild type mice underwent the microsurgical pull-through surgery, and stool was collected at the time of surgery, and then either at 2 and 4 weeks after the operation, or when the mice developed enterocolitis. The mid-colon of all animals was collected, prepared and histologically graded for enterocolitis. Fecal DNA was isolated and bacterial 16S rRNA genes analyzed using Illumina sequencing.

RESULTS

Six Ednrb-/- mice developed HAEC with a mean enterocolitis score of 5.7, while the remaining 4 mutant and 8 WT mice remained free of enterocolitis by 4 weeks. The HAEC group had lower alpha diversity by Chao1 analysis compared with WT group, while the Ednrb-/- mice demonstrated distinct bacterial communities from WT mice on beta diversity analysis. The most striking finding was increased proportion of Akkermansia and reduced Bacteroidetes compared with the NO HAEC and WT groups, suggesting Akkermansia may contribute to development of enterocolitis while Bacteroidetes may be protective. Less abundant genera that were reduced in HAEC were Dysgonomas and Clostridium XIVa which may play a protective role.

CONCLUSIONS

This is the first study to identify Akkermansia as potentially playing a role in HAEC, either as a pathobiont taxa contributing to pathogenesis of enterocolitis, or possibly a protective commensal taxa expanded in response to inflammation. These findings characterized the dynamic shifts in the gut microbial communities through the onset of post pull-through HAEC, and suggests that there may be identifiable bacterial community differences in HSCR patients that are high risk for developing HAEC.

Critical evaluation of the Hirschsprung-associated enterocolitis (HAEC) score: A multicenter study of 116 children with Hirschsprung disease

OBJECTIVE

To identify the optimal clinical criteria to diagnose Hirschsprung-associated enterocolitis (HAEC) in children with Hirschsprung disease (HSCR).

BACKGROUND

HAEC is the most common life-threatening complication in HSCR patients, yet the diagnostic criteria for HAEC remain unclear. The consensus-based HAEC scoring system was not validated using patient data, thereby making its diagnostic accuracy uncertain.

METHODS

From 2009 to 2015, consecutive children with HSCR underwent retrospective evaluation of their medical records, and questionnaire-directed parent interviews to identify treatment of suspected HAEC episodes and the 16 clinical criteria in the HAEC score. Logistic regression modeling was employed to identify criteria predicting suspected HAEC episodes.

RESULTS

One hundred sixteen HSCR patients met inclusion criteria, 43 patients (37.1%) were treated for at least one suspected HAEC episode. An HAEC score of 4 maximized the sum of sensitivity (83.7%) and specificity (98.6%) while the previously established cut-off score of 10 showed lower sensitivity (41.9%) with perfect specificity. Multivariable analysis identified four criteria utilized to create a new HAEC Risk score with performance characteristics similar to the HAEC score cutoff of 4.

CONCLUSION

When using the HAEC score, a cutoff of 4 should be used rather than 10, which under-diagnosed patients with HAEC. Alternatively, the new HAEC Risk score could be employed.

LEVEL OF EVIDENCE

Diagnostic Study, Level 3.

Hirschsprung disease - integrating basic science and clinical medicine to improve outcomes

Hirschsprung disease is defined by the absence of enteric neurons at the end of the bowel. The enteric nervous system (ENS) is the intrinsic nervous system of the bowel and regulates most aspects of bowel function. When the ENS is missing, there are no neurally mediated propulsive motility patterns, and the bowel remains contracted, causing functional obstruction. Symptoms of Hirschsprung disease include constipation, vomiting, abdominal distension and growth failure. Untreated disease usually causes death in childhood because bloodstream bacterial infections occur in the context of bowel inflammation (enterocolitis) or bowel perforation. Current treatment is surgical resection of the bowel to remove or bypass regions where the ENS is missing, but many children have problems after surgery. Although the anatomy of Hirschsprung disease is simple, many clinical features remain enigmatic, and diagnosis and management remain challenging. For example, the age of presentation and the type of symptoms that occur vary dramatically among patients, even though every affected child has missing neurons in the distal bowel at birth. In this Review, basic science discoveries are linked to clinical manifestations of Hirschsprung disease, including partial penetrance, enterocolitis and genetics. Insights into disease mechanisms that might lead to new prevention, diagnostic and treatment strategies are described.

Increased Risk of Inflammatory Bowel Disease in a Population-based Cohort Study of Patients With Hirschsprung Disease

OBJECTIVES

Hirschsprung disease (HSCR) has previously been associated with inflammatory bowel disease (IBD). There are no data to show how common this association is. The aim of the present study was to assess the risk of IBD in individuals with HSCR in a population-based cohort.

METHODS

This was a nationwide, population-based cohort study. The study exposure was HSCR and the study outcome was IBD. The cohort included all individuals with HSCR registered in the Swedish National Patient Register between 1964 and 2013 and 10 age- and sex-matched controls per patient, randomly selected from the Swedish Population Register. Individuals with IBD were identified in the Swedish National Patient Register. Data were validated by checking for relevant surgical procedures, and, or prescription of drugs for IBD registered in the Swedish Drug Registry.

RESULTS

The cohort comprised 739 individuals with HSCR (565 boys) and 7390 controls (5650 boys). The median age at diagnosis of IBD was not different between the groups; 19 years (5-34) versus 21 years (7-37), P = 0.21. Twenty of the 739 individuals with HSCR and 41 of the 7390 controls had IBD, odds ratio 4.99, and 95% confidence interval 2.85 to 8.45. In the exposed group, 15 individuals had Crohn disease and 5 ulcerative colitis at their latest admission compared to 18 individuals with Crohn disease and 23 with ulcerative colitis in the unexposed group, P = 0.030.

CONCLUSION

There is an increased risk of IBD in patients with HSCR, which should be considered in clinical practice.

Increased population of immature enteric glial cells in the resected proximal ganglionic bowel of Hirschsprung's disease patients

BACKGROUND

Enteric glial cells are essential for normal gastrointestinal function. Abnormalities in glial structure, development, or function lead to disturbances in gastrointestinal physiology. Fatty acid-binding protein 7 (FABP7) is a marker of immature enteric glial cells, whereas S100 is expressed only by mature glial cells. Patients with Hirschsprung's disease (HSCR) often suffer from dysmotility and enterocolitis despite proper surgery. We designed this study to determine the distribution and expression of glial cells in patients with HSCR compared to normal controls.

METHODS

We investigated FABP7, S100, and PGP 9.5 expressions in both the ganglionic and aganglionic bowel of patients with HSCR (n = 6) versus normal control colon (n = 6). Protein distribution was assessed by using immunofluorescence and confocal microscopy. Gene and protein expressions were quantified using quantitative real-time polymerase chain reaction (qPCR), Western blot analysis, and densitometry.

RESULTS

qPCR and Western blot analysis demonstrated a significantly increased FABP7 expression in ganglionic specimens compared to control specimen (P < 0.05). Confocal microscopy revealed FABP7⁺ glia cells lie under the colonic epithelium and in close apposition to enteric neurons in the ganglionic bowel.

CONCLUSIONS

The significantly increased number of immature enteric glial cells (EGCs) in the ganglionic bowel of HSCR patients may have adverse effect on the function of enteric neurons and intestinal barrier and thus predispose these patients to intestinal motility problems and enterocolitis.

Pediatric intestinal transplantation

The field of intestinal transplantation has experienced dramatic growth since the first reported cases 3 decades ago. Improvements in operative technique, donor assessment and immunosuppressive protocols have afforded children who suffer from life-threatening complications of intestinal failure a chance at long-term survival. As experience has grown, newer diseases, with more systemic manifestations have arisen as potential indications for transplant. After discussing the historical developments of intestinal transplant as a backdrop, this review focuses on the specific pre-operative indications for transplant as well as the great success that intestinal rehabilitation has witnessed over the past decade. A detailed discussion of evolution of immunosuppressive strategies is followed a general review of the common infectious complications experienced by children after intestinal transplant as well as the current long- and short-term results, including a section on new research on the quality of life in this challenging population of patients.

NOS-interacting protein (NOSIP) is increased in the colon of patients with Hirschsprungs's disease

PURPOSE

Hirschsprung's associated enterocolitis (HAEC) is the most common cause of morbidity and mortality in Hirschsprung's disease (HSCR). Nitric oxide (NO) mediates intestinal homoeostasis and is inhibited by NOSIP, a modulator of NO production. We designed this study to investigate the expression of NOSIP in the colon of patients with HSCR.

METHODS

We investigated NOSIP, endothelial NO synthase, and neuronal NO synthase expression in both the aganglionic and ganglionic regions of HSCR patients (n=10) versus normal control colon (n=10). Protein distribution was assessed by using immunofluorescence and confocal microscopy. Gene and protein expression were quantified using quantitative real-time polymerase chain reaction (qPCR), Western blot analysis, and densitometry.

MAIN RESULTS

qPCR and Western blot analysis demonstrate that NOSIP was significantly increased in the aganglionic and ganglionic colon compared to controls (p<0.05). Confocal microscopy revealed a markedly increased expression of NOSIP in the colon epithelium of patients with HSCR compared to controls.

CONCLUSION

To our knowledge, we demonstrate for the first time the expression of NOSIP in the human colon. While NOSIP expression was increased in HSCR vs. non-HSCR patients, no significant difference was observed in patients with HAEC. The increased expression of NOSIP in the aganglionic and ganglionic bowel of HSCR may contribute to the development of enterocolitis by inhibiting local NO production in patients with Hirschsprung's disease.

LEVEL OF EVIDENCE

II.

Neural Crest Cells Contribute an Astrocyte-like Glial Population to the Spleen

Neural crest cells (NCC) are multi-potent cells of ectodermal origin that colonize diverse organs, including the gastrointestinal tract to form the enteric nervous system (ENS) and hematopoietic organs (bone marrow, thymus) where they participate in lymphocyte trafficking. Recent studies have implicated the spleen as an anatomic site for integration of inflammatory signals from the intestine with efferent neural inputs. We have previously observed alterations in splenic lymphocyte subsets in animals with defective migration of NCC that model Hirschsprung's disease, leading us to hypothesize that there may be a direct cellular contribution of NCC to the spleen. Here, we demonstrate that NCC colonize the spleen during embryogenesis and persist into adulthood. Splenic NCC display markers indicating a glial lineage and are arranged anatomically adjacent to blood vessels, pericytes and nerves, suggesting an astrocyte-like phenotype. Finally, we identify similar neural-crest derived cells in both the avian and non-human primate spleen, showing evolutionary conservation of these cells.

Altered expression of IL36γ and IL36 receptor (IL1RL2) in the colon of patients with Hirschsprung's disease

PURPOSE

Hirschsprung's disease associated enterocolitis (HAEC) is the most common cause of morbidity and mortality in Hirschsprung's disease (HSCR). Altered intestinal epithelial barrier function and abnormal microbiota are implicated in the pathogenesis of HAEC. IL-36γ, a member of the IL-1 superfamily, is involved in host defense and contributes to proinflammatory responses and development of inflammatory diseases. The IL36 receptor (IL1RL2) is an important mediator molecule in the inflammatory response. Animal data suggests that IL1RL2 is involved in mucosal healing. We designed this study to investigate the hypothesis that the IL-36γ axis is altered in HSCR.

METHODS

We investigated IL-36γ and IL1RL2 expression in ganglionic and aganglionic bowel of HSCR patients (n = 10) and controls (n = 10). qPCR, Western blotting and confocal immunofluorescence were performed.

MAIN RESULTS

qPCR and Western blot analysis revealed that IL-36γ is strongly expressed in the aganglionic and ganglionic colon of patients with HSCR. ILR1L2 expression was significantly decreased in HSCR specimens compared to controls (p < 0.05). Confocal microscopy revealed a markedly increased expression of IL36γ in the colonic epithelium of patients with HSCR compared to controls. IL1RL2 was localized in the colonic epithelium and showed a markedly decreased expression in all HSCR specimens.

CONCLUSION

To our knowledge, we report for the first time the expression of IL36γ and ILRL2 in the colon of patients with HSCR. The increased expression of IL36γ and the markedly decreased expression of IL1RL2 in the aganglionic and ganglionic bowel in HSCR may result in an increased inflammatory response and altered mucosal response healing leading to the susceptibility to develop HAEC.

The enteric nervous system promotes intestinal health by constraining microbiota composition

Sustaining a balanced intestinal microbial community is critical for maintaining intestinal health and preventing chronic inflammation. The gut is a highly dynamic environment, subject to periodic waves of peristaltic activity. We hypothesized that this dynamic environment is a prerequisite for a balanced microbial community and that the enteric nervous system (ENS), a chief regulator of physiological processes within the gut, profoundly influences gut microbiota composition. We found that zebrafish lacking an ENS due to a mutation in the Hirschsprung disease gene, sox10, develop microbiota-dependent inflammation that is transmissible between hosts. Profiling microbial communities across a spectrum of inflammatory phenotypes revealed that increased levels of inflammation were linked to an overabundance of pro-inflammatory bacterial lineages and a lack of anti-inflammatory bacterial lineages. Moreover, either administering a representative anti-inflammatory strain or restoring ENS function corrected the pathology. Thus, we demonstrate that the ENS modulates gut microbiota community membership to maintain intestinal health.