Very Early Onset-IBD: evidence for the need of a multidisciplinary approach

Considerations in Paediatric and Adolescent Inflammatory Bowel Disease

The incidence of inflammatory bowel disease [IBD] is rising most rapidly among children and adolescents. Paediatric-onset IBD is associated with a more extensive and severe disease course compared to adult-onset IBD. At a young age, screening for underlying genetic and immunological disorders is important and may impact treatment management. Early and effective treatment is crucial to reach disease remission and prevent complications of ongoing active disease. In children with Crohn's disease, exclusive enteral nutrition is an effective induction therapy. Other promising dietary therapies, such as the Crohn's disease exclusion diet, are emerging. Within paediatric IBD, anti-tumour necrosis factor therapy is the only approved biological thus far and additional treatment options are crucially needed. Other biological therapies, such as vedolizumab and ustekinumab, are currently prescribed off-label in this population. A specific challenge in paediatric IBD is the unacceptable and major delay in approval of drugs for children with IBD. A guided transfer period of paediatric patients to adult care is associated with improved disease outcomes and is required. Major knowledge gaps and challenges within paediatric IBD include the aetiology, diagnostics, and monitoring of disease, tailoring of treatment, and both understanding and coping with the physical and psychological consequences of living with IBD. Challenges and research gaps in paediatrics should be addressed without any delay in comparison with the adult field, in order to ensure a high quality of care for all patients with IBD, irrespective of the age of onset.

Hereditary Multiple Intestinal Atresia With a Novel TTC7A Pathogenic Variant: Gastrointestinal Manifestations in Two Cases

Hereditary multiple intestinal atresia (HMIA) with TTC7A mutation is caused by homozygous or compound heterozygous TTC7A gene mutation. It is characterized by multiple small and large intestinal atresias and/or stenoses. TTC7A mutation is described in some patients with inflammatory bowel disease and mild-severe forms of severe combined immunodeficiency without intestinal atresia or stenosis. We present 2 cases of intestinal atresia and documented TTC7A mutation with a novel variant. Both cases had different clinical and pathological manifestations. The first case is a male infant born at 35 weeks of gestation with failure to pass meconium. Intestinal biopsy reveals apoptotic enteropathy with villous atrophy and increased mucosal eosinophils. The second case is referred at birth for antenatally detected umbilical hernia, polyhydramnios and possible upper intestinal obstruction. The resected specimen reveals ileal atresia with partial villous atrophy, decreased number of lamina propria inflammatory cells and absence of plasma cells. In conclusion, these cases reflect an emerging TTC7A pathogenic variant with different histological manifestations and leads to characterization as immune dysregulation disorder. There is a need to differentiate TTC7A mutation associated ones from cases labeled as very early onset IBD and rule out other hereditary immunodeficiencies.

Clinicopathologic Features of Primary Immunodeficiency Monogenic Disease-related Very Early Onset Inflammatory Bowel Disease: Focus on Gastrointestinal Histologic Features in IFIH1 Mutations

Very early onset inflammatory bowel disease (VEO-IBD) is a clinical term referring to IBD-like symptomatology arising in children younger than 6 years. VEO-IBD may be due to polygenic etiology in "pure" IBD (Crohn disease-CD and ulcerative colitis-UC), or it may be caused by primary immunodeficiency underlined by monogenic disease. Primary immunodeficiency monogenic diseases have a Mendelian inheritance and affect the immune system with multiorgan morbidity and possible effects on the gastrointestinal system. Primary Immunodeficiency monogenic diseases differ from "pure" IBD as the latter primarily affect the gastrointestinal tract with mitigated extraintestinal symptomatology. Since their first description, primary immunodeficiency monogenic diseases, although rare, have been the subject of increasing interest due to their dramatic phenotype, difficulty in reaching a timely diagnosis, and specific therapeutic approach. In this paper, we present a brief review of primary immunodeficiency monogenic diseases, focusing on to their clinicopathologic features as well as delving, in greater detail, into monogenic diseases caused by IFIH1 mutations. The clinicopathologic features of 4 patients with IFIH1, a gene involved in interferon pathway deficiency, will be described using a histologic pattern of damage approach confirming the need to avoid the histologic diagnosis of VEO-IBD in children younger than 6 years.

Marine Algae and Deriving Biomolecules for the Management of Inflammatory Bowel Diseases: Potential Clinical Therapeutics to Decrease Gut Inflammatory and Oxidative Stress Markers?

The term "inflammatory bowel disease" (IBD) describes a class of relapse-remitting conditions that affect the gastrointestinal (GI) tract. Among these, Crohn's disease (CD) and ulcerative colitis (UC) are two of the most globally prevalent and debilitating conditions. Several articles have brought attention to the significant role that inflammation and oxidative stress cooperatively play in the development of IBD, offering a different viewpoint both on its etiopathogenesis and on strategies for the effective treatment of these conditions. Marine ecosystems may be a significant source of physiologically active substances, supporting the search for new potential clinical therapeutics. Based on this evidence, this review aims to comprehensively evaluate the activity of marine algae and deriving biomolecules in decreasing pathological features of CD and UC. To match this purpose, a deep search of the literature on PubMed (MEDLINE) and Google Scholar was performed to highlight primary biological mechanisms, the modulation of inflammatory and oxidative stress biochemical parameters, and potential clinical benefits deriving from marine species. From our findings, both macroalgae and microalgae have shown potential as therapeutic solutions for IBD due to their bioactive compounds and their anti-inflammatory and antioxidant activities which are capable of modulating markers such as cytokines, the NF-κB pathway, reactive oxidative and nitrosative species (ROS and RNS), trefoil factor 3 (TFF3), lactoferrin, SIRT1, etc. However, while we found promising preclinical evidence, more extensive and long-term clinical studies are necessary to establish the efficacy and safety of marine algae for IBD treatment.

Identification and Validation of the Diagnostic Markers for Inflammatory Bowel Disease by Bioinformatics Analysis and Machine Learning

Inflammatory bowel disease (IBD) is a chronic inflammatory disorder of the gastrointestinal tract which is mediated by the inappropriate immune responses. This study was aimed to identify novel diagnostic biomarkers for diagnosis of IBD and explore the relationship between the diagnostic biomarkers and infiltrated immune cells. GSE38713, GSE53306, and GSE75214 downloaded from the Gene Expression Omnibus (GEO) database were split into training and testing sets. Differentially expressed genes (DEGs) were screened using the "limma" package. Gene Ontology (GO) and KEGG pathway enrichment analysis of DEGs were performed by clusterProfiler package. The LASSO regression and support vector machine recursive feature elimination (SVM-RFE) algorithms were conducted to identify novel diagnostic biomarkers. The receiver operating characteristic (ROC) curve was applied to evaluate the diagnostic value of the candidate biomarkers. The relationship of the candidate biomarkers and infiltrating immune cells in IBD were evaluated by CIBERSOTR. Quantitative Real-Time PCR (qRT-PCR) was applied to measure the expression level of the biomarkers in IBD. A total of 289 dysregulated genes were identified as DEGs in IBD. These DEGs were significantly enriched in chemokine signaling pathway and cytokine-cytokine receptor interaction. RHOU was identified as a critical diagnostic gene in IBD, which was confirmed using ROC curve and qRT-PCR assays. Immune cell infiltration analysis showed that RHOU was correlated with macrophages M2, dendritic cells resting, mast cells resting, T cells CD4 memory resting, macrophages M0, and mast cells activated. Our results imply that RHOU may be a potential diagnostic biomarker for IBD.

Application of a pattern-based approach to histological diagnosis in very early onset IBD (VEO-IBD) in a multicentric cohort of children with emphasis on monogenic disease with IBD-like morphology

AIMS

Very early-onset inflammatory bowel disease (VEO-IBD) is a clinical umbrella term referring to IBD-like symptoms arising in children before the age of 6 years, encompassing both 'pure' IBD, such as ulcerative colitis (UC) and Crohn's disease (CD) and monogenic diseases (MDs), the latter often involving genes associated with primary immunodeficiencies. Moreover, histological features in gastrointestinal (GI) biopsies in MD can also have IBD-like morphology, making differential diagnosis difficult. Correct diagnosis is fundamental, as MDs show a more severe clinical course and their inadequate/untimely recognition leads to inappropriate therapy.

METHODS AND RESULTS

Biopsy samples from the lower and upper GI tract of 93 clinically diagnosed VEO-IBD children were retrospectively selected in a multicentre cohort and histologically re-evaluated by 10 pathologists blinded to clinical information. Each case was classified according to morphological patterns, including UC-like; CD-like; enterocolitis-like; apoptotic; eosinophil-rich; and IBD-unclassified (IBD-U). Nine (69%) MD children showed IBD-like morphology; only the IBD-U pattern correlated with MD diagnosis (P = 0.02) (available in 64 cases: 51 non-MD, true early-onset IBD/other; 13 MD cases). MD patients showed earlier GI symptom onset (18.7 versus 26.9 months) and were sent to endoscopy earlier (22 versus 37 months), these differences were statistically significant (P < 0.05). Upper GI histology was informative in 37 biopsies.

CONCLUSIONS

The diagnosis of the underlying cause of VEO-IBD requires a multidisciplinary setting, and pathology, while being one of the fundamental puzzle pieces, is often difficult to interpret. A pattern-based histological approach is therefore suggested, thus aiding the pathologist in VEO-IBD reporting and multidisciplinary discussion.

Long-term outcomes after enterostomy for very early-onset inflammatory bowel disease with interleukin-10 signaling deficiency

BACKGROUND

Very early-onset inflammatory bowel disease (VEOIBD) with interleukin-10 (IL10R) signaling deficiency usually requires enterostomy in patients who are refractory to traditional treatment. This study aimed to evaluate long-term outcomes after enterostomy for VEOIBD patients with IL10R signaling deficiency.

METHODS

The medical records of all patients undergoing enterostomy for signaling deficiency were retrospectively assessed during 2012.1-2022.7 in a tertiary teaching hospital, Children's Hospital of Fudan University, Shanghai, China. Data on disease history, diagnosis and details of enterostomy and stoma closure and follow-up were collected. Univariate and multivariate logistic regression analyses were used to evaluate the risk factors associated with the long-term outcome of delayed stoma closure.

RESULTS

A total of 46 patients underwent an enterostomy, 19 who required emergency enterostomy and 27 with selective enterostomy. After ten years of follow-up, 35 patients underwent hematopoietic stem cell transplantation (HSCT), and 25 patients were alive after HSCT. The median timeframe between HSCT and stoma closure was 19.6 [15.9,26.2] months. Nineteen patients underwent stoma closure and had an average age of 3.9 ± 1.5 years; 6 patients were waiting for stoma closure. Based on a univariate logistic model, risk factors significantly associated with late stoma closure were age at enterostomy and age at HSCT. However, multivariate logistic regression showed no statistically significant factor associated with late stoma closure. There was no significant difference between the stoma closure group and delay closure group in the z scores of weight for age at follow up.

CONCLUSIONS

This study determined the long-term outcomes after enterostomy for VEOIBD with interleukin-10 signaling deficiency. The appropriate time point of enterostomy and HSCT may improve quality of life in the long term.

Biological, genetic and epigenetic markers in ulcerative colitis

In this review, we have summarized the existing knowledge of ulcerative colitis (UC) markers based on current literature, specifically, the roles of potential new biomarkers, such as circulating, fecal, genetic, and epigenetic alterations, in UC onset, disease activity, and in therapy response. UC is a complex multifactorial inflammatory disease. There are many invasive and non-invasive diagnostic methods in UC, including several laboratory markers which are employed in diagnosis and disease assessment; however, colonoscopy remains the most widely used method. Common laboratory abnormalities currently used in the clinical practice include inflammation-induced alterations, serum autoantibodies, and antibodies against bacterial antigens. Other new serum and fecal biomarkers are supportive in diagnosis and monitoring disease activity and therapy response; and potential salivary markers are currently being evaluated as well. Several UC-related genetic and epigenetic alterations are implied in its pathogenesis and therapeutic response. Moreover, the use of artificial intelligence in the integration of laboratory biomarkers and big data could potentially be useful in clinical translation and precision medicine in UC management.

[Pediatric very early onset inflammatory bowel disease: Role of pathology]

Inflammatory bowel diseases (IBD), including Crohn's disease and ulcerative colitis, are a heterogeneous group of multifactorial pathologies, often polygenic, due to a dysregulated immune response in a genetically susceptible host. In children under 6 years of age, a significant proportion of IBD, named "very early onset inflammatory bowel diseases" (VEO-IBD), are monogenic disorders in more than one third of cases. Over 80 genes have been linked to VEO-IBD and pathological descriptions are sparce. In this clarification, we describe the clinical aspects of monogenic VEO-IBD and the main causative genes, as well as the various histological patterns observed in intestinal biopsies. The management of a patient with VEO-IBD should be a coordinated effort by a multidisciplinary team including pediatric gastroenterologists, immunologists, geneticists, and of course pediatric pathologists.

Null Function of Npr1 Disturbs Immune Response in Colonic Inflammation During Early Postnatal Stage

Natriuretic peptide receptor 1 (NPR1) is conventionally known as a regulator of vascular homeostasis. Here, we generated an Npr1 knockout mouse model with CRISPR/Cas9 technology and found that homozygous mice (Npr1-/-) exhibited weight loss and poor survival rate during early postnatal stage. Careful examination revealed unexpectedly that Npr1-/- mice developed colitis characterized by shortened colon, evident colonic mucosal damage, increased histopathological score, and higher colonic expression of proinflammatory cytokines interleukin-1B (IL1B) and -6 (IL6). RNA-sequencing analysis revealed that differentially expressed genes were prominently enriched in the biological pathways related to immune response in both spleen and colon of Npr1-/- mice. Cytofluorimetric analysis demonstrated that leukocytes in the spleen were significantly increased, particularly, the populations of neutrophil and CD3+ T cell were elevated but CD4+ T cells were decreased in Npr1-/- mice. Administration of 8-Br-cGMP, a downstream activator of NPR1, restored these immune-cell populations disturbed in Npr1-/- mice and lessened the colitis-related phenotypes. To validate the involvement of Npr1 in colitis, we examined another mouse model induced by dextran sodium sulfate (DSS) and found a decreased Npr1 expression and shifted immune-cell populations as well. Importantly, 8-Br-cGMP treatment exhibited a similar effect in the restoration of immune-cell populations and attenuation of colonic inflammation in DSS mice. Our data indicate that loss of Npr1 possibly interrupts immune response, which is critical to the pathogenesis of colitis in the early life.

Exome Sequencing Identifies the Extremely Rare ITGAV and FN1 Variants in Early Onset Inflammatory Bowel Disease Patients

Background

Molecular diagnosis of early onset inflammatory bowel disease (IBD) is very important for adopting suitable treatment strategies. Owing to the sparse data available, this study aims to identify the molecular basis of early onset IBD in Arab patients.

Methods

A consanguineous Arab family with monozygotic twins presenting early onset IBD was screened by whole exome sequencing (WES). The variants functional characterization was performed by a series of computational biology methods. The IBD variants were further screened in in-house whole exome data of 100 Saudi cohorts ensure their rare prevalence in the population.

Results

Genetic screening has identified the digenic autosomal recessive mode of inheritance of ITGAV (G58V) and FN1 (G313V) variants in IBD twins with early onset IBD. Findings from pathogenicity predictions, stability and molecular dynamics have confirmed the deleterious nature of both variants on structural features of the corresponding proteins. Functional biology data suggested that both genes show abundant expression in gastrointestinal tract and immune organs, involved in immune cell restriction, regulation of different immune related pathways. Data from knockout mouse models for ITGAV gene has revealed that the dysregulated expression of this gene impacts intestinal immune homeostasis. The defective ITGAV and FN1 involved in integrin pathway, are likely to induce intestinal inflammation by disturbing immune homeostasis.

Conclusions

Our findings provide novel insights into the molecular etiology of pediatric onset IBD and may likely pave way in developing genomic medicine.

Pathologist's approach to paediatric and neonatal eosinophilic gastrointestinal disorders

Children are not simply miniature adults. The evaluation of their gastrointestinal disorders is therefore different from that in full-grown adults and requires a particular clinical/pathologic approach.

Different studies have tried to assess the normal eosinophil distribution in the gastrointestinal tract in adults while very few studies have investigated the paediatric population, consequently complicating the pathologist’s ability in identifying an abnormal number of eosinophils in this setting of patients.

When evaluating gastrointestinal tract biopsies with eosinophilia, eosinophilic count must be considered along with other histological features like eosinophil distribution in the gastrointestinal wall, their degranulation, cryptitis and crypt abscesses, other accompanying inflammatory cells, apoptotic bodies, foreign material or microorganisms; these findings, although rarely specific, may be a useful aid for diagnosis.

Reports should not include a diagnosis of primary eosinophilic gastrointestinal disorders (EoGID) if clinical data and test results do not rule out other forms of gastrointestinal eosinophilia. A more descriptive definition like “with eosinophilic pattern” should be favoured over a specific diagnosis of “eosinophilic disorder” in order to avoid potential confusion between different entities.

Pediatric autoimmune disorders with gastrointestinal expressions: from bench to bedside

The gastrointestinal (GI) tract may be involved in systemic autoimmune diseases or may be the target of organ-specific autoimmunity. Autoimmune enteropathy (AIE) is a rare disorder characterized by severe and protracted diarrhea, weight loss from malabsorption and immune-mediated damage to the intestinal mucosa, generally occurring in infants and young children, only rarely in adult. The salient histopathologic features of AIE are most prominent in the small intestine: villous blunting, crypt hyperplasia, mononuclear cell inflammatory expansion of the lamina propria with intraepithelial lymphocytosis, crypt apoptosis and absence of Paneth cells, goblet cells or both. Esophagus, stomach and colon are frequently also involved. Anti-enterocyte antibodies are identified in the majority of cases, and their presence, even if variable, can help confirming the diagnosis.

The purpose of this review is to provide an overview of the latest immunological advances in AIE, as well as to offer a practical approach for histological diagnosis for 'general' pathologist.

Histopathology of intestinal villi in neonatal and paediatric age: main features with clinical correlation - Part I

The neonatal and paediatric spectrum of small bowel disorders encompass a wide variety of conditions, ranging from food allergies to life-threatening surgical emergencies or life-long medical conditions and, as such, it comes with a whole set of diagnostic challenges for the non-paediatric pathologist. Histologic examination is a cornerstone of diagnosis in a large number of diseases and may still provide important diagnostic clues in the appropriate clinical context. In this review, divided in two sections, we aim to provide a comprehensive histopathological summary of paediatric small bowel alteration and their differential diagnoses with a reference to the main clinical aspects required for appropriate interpretation. Specifically, in this first part, we describe congenital and metabolic disorders, intestinal lymphangiectasia, immunodeficiencies, GVHD, and necrotising enterocolitis.

Histopathology of intestinal villi in neonatal and paediatric age: main features with clinical correlation - Part II

In this paper, we will continue the description of histological findings of infantile and paediatric small bowel alterations with the main clinical pictures and differential diagnosis. We emphasise once again the need to evaluate the biopsies in an adequate clinical contest and with a systematic approach, including epithelial alterations, lamina propria changes, mucosal architecture, and the distribution of inflammation, together with other morphological signs more specific of certain diseases. We describe the histological findings of coeliac and Crohn’s disease, gastrointestinal food allergic diseases, Langerhans cell histiocytosis, nutritional deficiencies and infections. Finally, we suggest the principal issues in the drafting the pathological report for appropriate interpretation and usefulness in clinical practice.