Explore the vast range of titles available.

Faecal calprotectin (FCP) is a powerful tool to predict inflammatory bowel disease (IBD) in patients with gastrointestinal symptoms. In the paediatric patient population, the reference value of < 50 μg/g and the influence of age on FCP levels result in a high number of redundant investigations and specialist referrals. We assessed paediatric FCP levels, their diagnostic value and corresponding referral pathways from primary and secondary care. We analysed two cohorts from a precisely defined catchment area: one consisted of all FCPs measured in this area (n = 2788). The second cohort-a subset of the first cohort-consisted of FCP values and corresponding clinical data from children who were referred for possible IBD to our department (n = 373). In the first cohort, 47% of FCP levels were > 50 μg/g, 15% were ≥ 250 μg/g. Children < 1y had significantly (p < 0.001) higher FCP than older children. In the second cohort, 6.7% of children with an FCP of < 250 μg/g (or 8.6% with an FCP of < 600 μg/g) had IBD-all featured symptoms suggestive of IBD (e.g. bloody diarrhoea, nocturnal abdominal pain, weight loss) or abnormal blood tests. 76% of patients in whom raised FCP (> 50 μg/g) was the sole reason for being referred for suspected IBD did not have IBD. Children with an FCP < 600 μg/g and without matching symptoms suggestive of IBD are unlikely to have IBD. A higher FCP reference value may provide cost-effective improvement that could avoid redundant investigations and specialist referrals. A guideline for specialist referrals is proposed.

ObjectiveHuman intestinal epithelial organoids (IEOs) are increasingly being recognised as a highly promising translational research tool. However, our understanding of their epigenetic molecular characteristics and behaviour in culture remains limited.DesignWe performed genome-wide DNA methylation and transcriptomic profiling of human IEOs derived from paediatric/adult and fetal small and large bowel as well as matching purified human gut epithelium. Furthermore, organoids were subjected to in vitro differentiation and genome editing using CRISPR/Cas9 technology.ResultsWe discovered stable epigenetic signatures which define regional differences in gut epithelial function, including induction of segment-specific genes during cellular differentiation. Established DNA methylation profiles were independent of cellular environment since organoids retained their regional DNA methylation over prolonged culture periods. In contrast to paediatric and adult organoids, fetal gut-derived organoids showed distinct dynamic changes of DNA methylation and gene expression in culture, indicative of an in vitro maturation. By applying CRISPR/Cas9 genome editing to fetal organoids, we demonstrate that this process is partly regulated by TET1, an enzyme involved in the DNA demethylation process. Lastly, generating IEOs from a child diagnosed with gastric heterotopia revealed persistent and distinct disease-associated DNA methylation differences, highlighting the use of organoids as disease-specific research models.ConclusionsOur study demonstrates striking similarities of epigenetic signatures in mucosa-derived IEOs with matching primary epithelium. Moreover, these results suggest that intestinal stem cell-intrinsic DNA methylation patterns establish and maintain regional gut specification and are involved in early epithelial development and disease.

Epigenetic signatures are highly cell type specific. Separation of distinct cell populations is therefore desirable for all epigenetic studies. However, to date little information is available on whether separation protocols might influence epigenetic and/or gene expression signatures and hence might be less beneficial. We investigated the influence of two frequently used protocols to isolate intestinal epithelium cells (IECs) from 6 healthy individuals. Epithelial cells were isolated from small bowel (i.e. terminal ileum) biopsies using EDTA/DTT and enzymatic release followed by magnetic bead sorting via EPCAM labeled microbeads. Effects on gene/mRNA expression were analyzed using a real time PCR based expression array. DNA methylation was assessed by pyrosequencing of bisulfite converted DNA and methylated DNA immunoprecipitation (MeDIP). While cell purity was >95% using both cell separation approaches, gene expression analysis revealed significantly higher mRNA levels of several inflammatory genes in EDTA/DTT when compared to enzymatically released cells. In contrast, DNA methylation of selected genes was less variable and only revealed subtle differences. Comparison of DNA methylation of the epithelial cell marker EPCAM in unseparated whole biopsy samples with separated epithelium (i.e. EPCAM positive and negative fraction) demonstrated significant differences in DNA methylation between all three tissue fractions indicating cell type specific methylation patterns can be masked in unseparated tissue samples. Taken together, our data highlight the importance of considering the potential effect of cell separation on gene expression as well as DNA methylation signatures. The decision to separate tissue samples will therefore depend on study design and specific separation protocols.

Human beta-defensins (hBDs) are antimicrobial peptides known to play a major role in intestinal innate host defence. Altered mucosal expression of hBDs has been suggested to be implicated in chronic inflammatory bowel disease pathogenesis. However, little is known about expression of these peptides in children. Intestinal biopsies were obtained from the duodenum (n = 88), terminal ileum (n = 90) and ascending colon (n = 105) of children with Crohn's disease (n = 26), ulcerative colitis (n = 11) and healthy controls (n = 16). Quantitative real-time (RT) PCR was performed and absolute mRNA copy numbers analyzed for hBD1-3 as well as inflammatory cytokines IL-8 and TNF-alpha. Significant induction of hBD2 and hBD3 was observed in the inflamed terminal ileum and ascending colon of IBD children. In the ascending colon induction of hBD2 was found to be significantly lower in children with Crohn's disease compared to ulcerative colitis. A strong correlation was found between inducible defensins hBD2 and 3 and the inflammatory cytokines IL-8 and TNF-alpha, both in the terminal ileum and ascending colon. Our study demonstrates distinct changes in hBD expression throughout the intestinal tract of children with IBD, lending further support for their potential role in disease pathogenesis.

Immunohistochemistry allowed recent recognition of a distinct focal gastritis in Crohn's disease. Following reports of lymphocytic colitis and small bowel enteropathy in children with regressive autism, we aimed to see whether similar changes were seen in the stomach. We thus studied gastric antral biopsies in 25 affected children, in comparison to 10 with Crohn's disease, 10 with Helicobacter pylori infection, and 10 histologically normal controls. All autistic, Crohn's, and normal patients were H. pylori negative. Snap-frozen antral biopsies were stained for CD3, CD4, CD8, gammadelta T cells, HLA-DR, IgG, heparan sulphate proteoglycan, IgM, IgA, and C1q. Cell proliferation was assessed with Ki67. Distinct patterns of gastritis were seen in the disease states: diffuse, predominantly CD4+ infiltration in H. pylori, and focal-enhanced gastritis in Crohn's disease and autism, the latter distinguished by striking dominance of CD8+ cells, together with increased intraepithelial lymphocytes in surface, foveolar and glandular epithelium. Proliferation of foveolar epithelium was similarly increased in autism, Crohn's disease and H. pylori compared to controls. A striking finding, seen only in 20/25 autistic children, was colocalized deposition of IgG and C1q on the subepithelial basement membrane and the surface epithelium. These findings demonstrate a focal CD8-dominated gastritis in autistic children, with novel features. The lesion is distinct from the recently recognized focal gastritis of Crohn's disease, which is not CD8-dominated. As in the small intestine, there is epithelial deposition of IgG.

APOBEC mutational signatures SBS2 and SBS13 are common in many human cancer types. However, there is an incomplete understanding of its stimulus, when it occurs in the progression from normal to cancer cell and the APOBEC enzymes responsible. Here we whole-genome sequenced 342 microdissected normal epithelial crypts from the small intestines of 39 individuals and found that SBS2/SBS13 mutations were present in 17% of crypts, more frequent than most other normal tissues. Crypts with SBS2/SBS13 often had immediate crypt neighbors without SBS2/SBS13, suggesting that the underlying cause of SBS2/SBS13 is cell-intrinsic. APOBEC mutagenesis occurred in an episodic manner throughout the human lifespan, including in young children. APOBEC1 mRNA levels were very high in the small intestine epithelium, but low in the large intestine epithelium and other tissues. The results suggest that the high levels of SBS2/SBS13 in the small intestine are collateral damage from APOBEC1 fulfilling its physiological function of editing APOB mRNA. Whole-genome sequencing of healthy human epithelial crypts from the small intestines of 39 individuals highlights APOBEC enzymes as a common contributor to the overall mutational burden in this tissue.

ObjectiveEpigenetic mechanisms, including DNA methylation (DNAm), have been proposed to play a key role in Crohn’s disease (CD) pathogenesis. However, the specific cell types and pathways affected as well as their potential impact on disease phenotype and outcome remain unknown. We set out to investigate the role of intestinal epithelial DNAm in CD pathogenesis.DesignWe generated 312 intestinal epithelial organoids (IEOs) from mucosal biopsies of 168 patients with CD (n=72), UC (n=23) and healthy controls (n=73). We performed genome-wide molecular profiling including DNAm, bulk as well as single-cell RNA sequencing. Organoids were subjected to gene editing and the functional consequences of DNAm changes evaluated using an organoid-lymphocyte coculture and a nucleotide-binding oligomerisation domain, leucine-rich repeat and CARD domain containing 5 (NLRC5) dextran sulphate sodium (DSS) colitis knock-out mouse model.ResultsWe identified highly stable, CD-associated loss of DNAm at major histocompatibility complex (MHC) class 1 loci including NLRC5 and cognate gene upregulation. Single-cell RNA sequencing of primary mucosal tissue and IEOs confirmed the role of NLRC5 as transcriptional transactivator in the intestinal epithelium. Increased mucosal MHC-I and NLRC5 expression in adult and paediatric patients with CD was validated in additional cohorts and the functional role of MHC-I highlighted by demonstrating a relative protection from DSS-mediated mucosal inflammation in NLRC5-deficient mice. MHC-I DNAm in IEOs showed a significant correlation with CD disease phenotype and outcomes. Application of machine learning approaches enabled the development of a disease prognostic epigenetic molecular signature.ConclusionsOur study has identified epigenetically regulated intestinal epithelial MHC-I as a novel mechanism in CD pathogenesis.

Clinical psychology intervention in paediatric gastroenterology is vital given the biopsychosocial aetiology of paediatric functional gastrointestinal disorders, and the psychological impact of chronic conditions. The aim was to assess the availability and benefit of clinical psychology in paediatric gastroenterology across the UK and Germany. A retrospective assessment of referrals (n = 936 referrals) to clinical psychology was performed at our tertiary paediatric gastroenterology centre between 2010 and 2018. The availability of clinical psychologists and outcome of psychology intervention for children with functional abdominal pain were also assessed. Access to clinical psychology across the UK and Germany was assessed using an online questionnaire. We observed a substantial rise in the number of clinical psychology referrals between 2010 and 2018. Increasing demand was not matched by sufficient increase in availability of clinical psychology, leading to longer waiting times. A major benefit of clinical psychology intervention was highlighted with 95% of patients (n = 20) reporting a significant reduction in symptoms. Of the 12 centres who responded, 11 centres have direct access to clinical psychology with a mean of 13% of patients requiring psychology referrals annually.Conclusion: Despite evidence of its benefit and increasing demand, there is insufficient access to clinical psychological services, highlighting the urgent need to address this important issue.What is known:• The biopsychosocial pathophysiology of functional gastrointestinal disorders involves a disordered brain-gut interaction, which emphasizes the close link between psychological factors and altered gut function.• Psychological intervention, as an adjunct to medical treatment, improves outcomes in paediatric patients with gastrointestinal (GI) disease such as functional gastrointestinal disorders and inflammatory bowel diseasesWhat is new:• There is a rising number of referrals from paediatric gastroenterology to clinical psychology in our centre which is not met by a sufficient increase in the availability of clinical psychologists. Similarly, access to clinical psychological services is lacking in several paediatric gastroenterology centres in the UK and Germany.• Strategic action is required to address this important gap in the care of children suffering from GI diseases.

SummaryAround 1 in 4 patients with inflammatory bowel disease (IBD) present in childhood, the majority around the time of their pubertal growth spurt. This presents challenges over and above those of managing IBD in adults as this period is a time of dramatic psychological and physical transition for a child. Growth and nutrition are key priorities in the management of adolescents and young adults with IBD. Growth failure in IBD is characterized by delayed skeletal maturation and a delayed onset of puberty, and is best described in terms of height-for-age standard deviation score (Z score) or by variations in growth velocity over a period of 3–4 months. Growth failure is common at presentation in Crohn's disease (CD), but less common in ulcerative colitis (UC). The etiology of growth failure is multifactorial. Principal determinants, however, include the inflammatory process per se, with proinflammatory cytokines (e.g., IL-1β, IL-6) being directly implicated. Furthermore, poor nutrition and the consequences of prolonged corticosteroid use also contribute to the significant reduction in final adult height of almost 1 in 5 children. Initially a prompt, where possible steroid-free, induction of remission is indicated. The ideal is then to sustain a relapse-free remission until growth is complete, which is often not until early adulthood. These goals can often be achieved with a combination of exclusive enteral nutrition (EEN) and early use of immunosuppressants. The advent of potent and efficacious biological agents considerably improves the range of growth-sparing interventions available to children around puberty, although well-timed surgery remains another highly effective means of achieving remission and significant catch-up growth. We carried out a systematic review of publications to identify the best available evidence for managing growth failure in children with IBD. Despite the paucity of high-quality publications, sufficient data were available in the literature to allow practical, evidence-based where possible, management guidelines to be formulated. Although there is clear evidence that exclusive enteral nutrition achieves mucosal healing, its effect on growth has only been assessed at 6 months. In contrast to corticosteroids, EEN has no negative effect on growth. Corticosteroids remain the key therapy responsible for medication-induced growth impairment, although the use of budesonide in selected patients may minimize the steroid effect on dividing growth plates. Immunosuppressants have become a mainstay of treatment in children with IBD, and are being used earlier in the disease course than ever before. However, there are currently no long-term data reporting better growth outcome if these agents are introduced very soon after diagnosis. In comparison, recent data from a large prospective trial of infliximab in children with moderate to severe CD suggested significant catch-up growth during the first year of regular infusions. The only other intervention that has documented clear catch-up growth has been surgical resection. Resection of localized CD, in otherwise treatment-resistant children, early in the disease process achieves clear catch-up growth within the next 6 months. There are no data available that growth hormone improves final adult height in children with CD. In conjunction with expert endocrinological support, pubertal delay, more common in boys, may be treated with parenteral testosterone if causing significant psychological problems. The optimal management of children and adolescents requires a multidisciplinary approach frequently available within the pediatric healthcare setting. Dedicated dietetic support, along with nurse-specialist, child psychologist, and with closely linked medical and surgical care will likely achieve the best possible start for children facing a lifetime of chronic gut disease.

There is increasing recognition that Henoch-Schonlein purpura may present in an atypical form in which gastrointestinal symptoms may predominate, and classic cutaneous changes may be delayed or absent. This may lead to significant diagnostic delay. We report the case of a 9-year-old girl who presented acutely with life-threatening gastrointestinal haemorrhage from multiple intestinal sites, with no skin rash and only mild evidence of renal involvement. Henoch-Schonlein purpura was confirmed by finding IgA deposition on vessels within gastric and duodenal mucosa, while immunohistochemistry also identified dense focal T cell infiltration in gastric mucosa and within duodenal epithelium. After initial stabilisation, the patient became shocked due to further gastrointestinal haemorrhage. Isotope bleeding scan identified multiple bleeding sites. Her endoscopically confirmed gastritis was sufficiently severe to preclude corticosteroids, and she was thus treated with intravenous immunoglobulin. This therapy induced prompt and sustained resolution of symptoms, and she has remained well since. Our patient's response concords with previous reports in corticosteroid-resistant cases to suggest that severe intestinal Henoch-Schonlein purpura may respond preferentially to intravenous immunoglobulin (IVIG) therapy. In severe cases where there is significant gastritis, IVIG provides an effective alternative to corticosteroids that may be employed as first-line therapy.