Patient-derived organoid biobank identifies epigenetic dysregulation of intestinal epithelial MHC-I as a novel mechanism in severe Crohn's Disease.

OBJECTIVE: Epigenetic 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. DESIGN: We 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. RESULTS: We 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. CONCLUSIONS: Our study has identified epigenetically regulated intestinal epithelial MHC-I as a novel mechanism in CD pathogenesis.

Culture-Associated DNA Methylation Changes Impact on Cellular Function of Human Intestinal Organoids.

BACKGROUND & AIMS: Human intestinal epithelial organoids (IEOs) are a powerful tool to model major aspects of intestinal development, health, and diseases because patient-derived cultures retain many features found in vivo. A necessary aspect of the organoid model is the requirement to expand cultures in vitro through several rounds of passaging. This is of concern because the passaging of cells has been shown to affect cell morphology, ploidy, and function. METHODS: Here, we analyzed 173 human IEO lines derived from the small and large bowel and examined the effect of culture duration on DNA methylation (DNAm). Furthermore, we tested the potential impact of DNAm changes on gene expression and cellular function. RESULTS: Our analyses show a reproducible effect of culture duration on DNAm in a large discovery cohort as well as 2 publicly available validation cohorts generated in different laboratories. Although methylation changes were seen in only approximately 8% of tested cytosine-phosphate-guanine dinucleotides (CpGs) and global cellular function remained stable, a subset of methylation changes correlated with altered gene expression at baseline as well as in response to inflammatory cytokine exposure and withdrawal of Wnt agonists. Importantly, epigenetic changes were found to be enriched in genomic regions associated with colonic cancer and distant to the site of replication, indicating similarities to malignant transformation. CONCLUSIONS: Our study shows distinct culture-associated epigenetic changes in mucosa-derived human IEOs, some of which appear to impact gene transcriptomic and cellular function. These findings highlight the need for future studies in this area and the importance of considering passage number as a potentially confounding factor.

Thromboprophylaxis Use in Paediatric Inflammatory Bowel Disease: An International RAND Appropriateness Panel.

BACKGROUND AND AIMS: Thromboprophylaxis use in paediatric inflammatory bowel disease [IBD] is inconsistent. Current guidelines only support treating children with acute severe colitis with risk factors. We convened an international RAND panel to explore thromboprophylaxis in paediatric IBD inpatients in the context of new evidence. METHODS: We convened a geographically diverse 14-person panel of paediatric gastroenterologists alongside supporting experts. An online survey was sent before an online meeting. Panellists were asked to rate the appropriateness of thromboprophylaxis in hospitalised paediatric IBD patients via 27 scenarios of varying ages, gender, and phenotype, with and without thrombotic risk factors. Anonymised results were presented at the meeting. A second modified survey was distributed to all panellists present at the meeting. Results from the second survey constitute the RAND panel results. The validated RAND disagreement index defined disagreement when ≥ 1. RESULTS: The combined outcome of thromboprophylaxis being considered appropriate until discharge and inappropriate to withhold was seen in 20 of 27 scenarios, including: all patients with new-onset acute severe colitis; all flares of known ulcerative colitis, irrespective of risk factors except in pre-pubescent patients with limited disease and no risk factors; and all Crohn's patients with risk factors. Disagreement was seen in five scenarios regarding Crohn's without risk factors, where outcomes were already uncertain. CONCLUSIONS: RAND panels are an established method to assess expert opinion in areas of limited evidence. This work therefore constitutes neither a guideline nor a consensus; however, the findings suggest a need to re-evaluate the role of thromboprophylaxis in future guidelines.

Transition Services for Paediatric Inflammatory Bowel Disease: A Multicentre Study of Practice in the United Kingdom.

OBJECTIVES: Patients with paediatric inflammatory bowel disease (IBD) constitute one of the largest cohorts requiring transition from paediatric to adult services. Standardised transition care improves short and long-term patient outcomes. This study aimed to detail the current state of transition services for IBD in the United Kingdom (UK). METHODS: We performed a nationwide study to ascertain current practice, facilities and resources for children and young people with IBD. Specialist paediatric IBD centres were invited to contribute data on: timing of transition/transfer of care; transition resources available including clinics, staff and patient information; planning for future improvement. RESULTS: Twenty of 21 (95%) of invited centres responded. Over 90% of centres began the transition process below 16 years of age and all had completed transfer to adult care at 18 years of age. The proportion of patients in the transition process at individual centres varied from 10% to 50%.Joint clinics were held in every centre, with a mean of 12.9 clinics per year. Adult and paediatric gastroenterologists attended at all sites. Availability of additional team members was patchy across the UK, with dietetic, psychological and surgical attendance available in <50% centres. A structured transition tool was used in 75% of centres. Sexual health, contraception and pregnancy were discussed by <60% of teams. CONCLUSIONS: This study provides real-world clinical data on UK-wide transition services. These data can be used to develop a national strategy to complement current transition guidelines, focused on standardising services whilst allowing for local implementation.

Adaptations to the current ECCO/ESPGHAN guidelines on the management of paediatric acute severe colitis in the context of the COVID-19 pandemic: a RAND appropriateness panel.

OBJECTIVE: Paediatric acute severe colitis (ASC) management during the novel SARS-CoV-2/COVID-19 pandemic is challenging due to reliance on immunosuppression and the potential for surgery. We aimed to provide COVID-19-specific guidance using the European Crohn's and Colitis Organisation/European Society for Paediatric Gastroenterology, Hepatology and Nutrition guidelines for comparison. DESIGN: We convened a RAND appropriateness panel comprising 14 paediatric gastroenterologists and paediatric experts in surgery, rheumatology, respiratory and infectious diseases. Panellists rated the appropriateness of interventions for ASC in the context of the COVID-19 pandemic. Results were discussed at a moderated meeting prior to a second survey. RESULTS: Panellists recommended patients with ASC have a SARS-CoV-2 swab and expedited biological screening on admission and should be isolated. A positive swab should trigger discussion with a COVID-19 specialist. Sigmoidoscopy was recommended prior to escalation to second-line therapy or colectomy. Methylprednisolone was considered appropriate first-line management in all, including those with symptomatic COVID-19. Thromboprophylaxis was also recommended in all. In patients requiring second-line therapy, infliximab was considered appropriate irrespective of SARS-CoV-2 status. Delaying colectomy due to SARS-CoV-2 infection was considered inappropriate. Corticosteroid tapering over 8-10 weeks was deemed appropriate for all. After successful corticosteroid rescue, thiopurine maintenance was rated appropriate in patients with negative SARS-CoV-2 swab and asymptomatic patients with positive swab but uncertain in symptomatic COVID-19. CONCLUSION: Our COVID-19-specific adaptations to paediatric ASC guidelines using a RAND panel generally support existing recommendations, particularly the use of corticosteroids and escalation to infliximab, irrespective of SARS-CoV-2 status. Consideration of routine prophylactic anticoagulation was recommended.

Transcription and DNA Methylation Patterns of Blood-Derived CD8+ T Cells Are Associated With Age and Inflammatory Bowel Disease But Do Not Predict Prognosis.

BACKGROUND & AIMS: Gene expression patterns of CD8+ T cells have been reported to correlate with clinical outcomes of adults with inflammatory bowel diseases (IBD). We aimed to validate these findings in independent patient cohorts. METHODS: We obtained peripheral blood samples from 112 children with a new diagnosis of IBD (71 with Crohn's disease and 41 with ulcerative colitis) and 19 children without IBD (controls) and recorded medical information on disease activity and outcomes. CD8+ T cells were isolated from blood samples by magnetic bead sorting at the point of diagnosis and during the course of disease. Genome-wide transcription (n = 192) and DNA methylation (n = 66) profiles were generated using Affymetrix and Illumina arrays, respectively. Publicly available transcriptomes and DNA methylomes of CD8+ T cells from 3 adult patient cohorts with and without IBD were included in data analyses. RESULTS: Previously reported CD8+ T-cell prognostic expression and exhaustion signatures were only found in the original adult IBD patient cohort. These signatures could not be detected in either a pediatric or a second adult IBD cohort. In contrast, an association between CD8+ T-cell gene expression with age and sex was detected across all 3 cohorts. CD8+ gene transcription was clearly associated with IBD in the 2 cohorts that included non-IBD controls. Lastly, DNA methylation profiles of CD8+ T cells from children with Crohn's disease correlated with age but not with disease outcome. CONCLUSIONS: We were unable to validate previously reported findings of an association between CD8+ T-cell gene transcription and disease outcome in IBD. Our findings reveal the challenges of developing prognostic biomarkers for patients with IBD and the importance of their validation in large, independent cohorts before clinical application.

Impact of COVID-19 on diagnosis and management of paediatric inflammatory bowel disease during lockdown: a UK nationwide study.

BACKGROUND: COVID-19 has impacted on healthcare provision. Anecdotally, investigations for children with inflammatory bowel disease (IBD) have been restricted, resulting in diagnosis with no histological confirmation and potential secondary morbidity. In this study, we detail practice across the UK to assess impact on services and document the impact of the pandemic. METHODS: For the month of April 2020, 20 tertiary paediatric IBD centres were invited to contribute data detailing: (1) diagnosis/management of suspected new patients with IBD; (2) facilities available; (3) ongoing management of IBD; and (4) direct impact of COVID-19 on patients with IBD. RESULTS: All centres contributed. Two centres retained routine endoscopy, with three unable to perform even urgent IBD endoscopy. 122 patients were diagnosed with IBD, and 53.3% (n=65) were presumed diagnoses and had not undergone endoscopy with histological confirmation. The most common induction was exclusive enteral nutrition (44.6%). No patients with a presumed rather than confirmed diagnosis were started on anti-tumour necrosis factor (TNF) therapy.Most IBD follow-up appointments were able to occur using phone/webcam or face to face. No biologics/immunomodulators were stopped. All centres were able to continue IBD surgery if required, with 14 procedures occurring across seven centres. CONCLUSIONS: Diagnostic IBD practice has been hugely impacted by COVID-19, with >50% of new diagnoses not having endoscopy. To date, therapy and review of known paediatric patients with IBD has continued. Planning and resourcing for recovery is crucial to minimise continued secondary morbidity.

The landscape of somatic mutation in normal colorectal epithelial cells.

The colorectal adenoma-carcinoma sequence has provided a paradigmatic framework for understanding the successive somatic genetic changes and consequent clonal expansions that lead to cancer1. However, our understanding of the earliest phases of colorectal neoplastic changes-which may occur in morphologically normal tissue-is comparatively limited, as for most cancer types. Here we use whole-genome sequencing to analyse hundreds of normal crypts from 42 individuals. Signatures of multiple mutational processes were revealed; some of these were ubiquitous and continuous, whereas others were only found in some individuals, in some crypts or during certain periods of life. Probable driver mutations were present in around 1% of normal colorectal crypts in middle-aged individuals, indicating that adenomas and carcinomas are rare outcomes of a pervasive process of neoplastic change across morphologically normal colorectal epithelium. Colorectal cancers exhibit substantially increased mutational burdens relative to normal cells. Sequencing normal colorectal cells provides quantitative insights into the genomic and clonal evolution of cancer.

Headache and inflammatory bowel disease: think cerebral vein!

Cerebral vein thrombosis is a severe complication of inflammatory bowel disease, can cause non-specific symptoms and hence lead to delay in diagnosis. We report the case of an adolescent with inflammatory bowel disease who developed extensive cerebral vein thrombosis requiring a ventriculoperitoneal shunt. Diagnosis was markedly delayed due to repeated misinterpretation of clinical signs and laboratory findings and the lack of reconsidering the working diagnosis despite the involvement of several medical subspecialties. The patient does not suffer from any neurological impairment. This case report highlights the need for clinicians to maintain vigilance for complications of chronic disease and encourages to cast doubt on the working diagnosis constantly.

Early Treatment Response Predicts Outcome in Paediatric Ulcerative Colitis: GASTROENTEROLOGY: INFLAMMATORY BOWEL DISEASE.

The disease course of children with ulcerative colitis (UC) varies substantially. Published data on predictors of disease outcomes in children remain scarce. We validate clinical predictors of outcomes in 93 children with UC in a single centre (age range: 2-18 years, minimum follow-up: 18 months). We stratified children into 3 groups according to their disease course, that is, 1 = mild (38/93, 40.9%), 2 = moderate (38/93, 40.9%), 3 = severe (17, 18.2%). Comparison of clinical and biochemical parameters was performed between groups using Chi-square, Mann-Whitney, and log-rank tests. Predictors of a severe disease course included pancolitis (P 0.01), low albumin (P 0.005), low haemoglobin at diagnosis (P 0.04), paediatric ulcerative colitis activity index (PUCAI) at 3 months, and nonresponse to steroids at 3 months (P 0.0001). In our cohort, failure to achieve remission at 3 months implied an 80% likelihood to require biologics or major surgery within 18 months. A specific 3-month review point is recommended to guide future management.

Real-life Anti-tumor Necrosis Factor Experience in More Than 500 Patients: High Co-immunosuppression Rates But Low Rates of Quantifying Treatment Response.

OBJECTIVE: The aim of this study was to measure the effectiveness, safety, and use of anti-tumor necrosis Factor (TNF) therapy in pediatric inflammatory bowel disease in the United Kingdom (UK). METHODS: Prospective UK audit of patients newly starting anti-TNF therapy. Disease severity was assessed using Physician Global Assessment +/or the Paediatric Crohn Disease Activity Index. RESULTS: A total of 37 centers participated (23/25 specialist pediatric inflammatory bowel disease sites). A total of 524 patients were included: 429 with Crohn disease (CD), 76 with ulcerative colitis (UC), and 19 with IBD unclassified (IBDU). Eighty-seven percent (488/562) of anti-TNF was infliximab; commonest indication was active luminal CD 77% (330/429) or chronic refractory UC/IBDU 56% (53/95); 79% (445/562) had concomitant co-immunosuppression. In CD (267/429 male), median time from diagnosis to treatment was 1.42 years (interquartile range 0.63-2.97). Disease (at initiation) was moderate or severe in 91% (156/171) by Physician Global Assessment compared to 41% (88/217) by Paediatric Crohn Disease Activity Index (Kappa (κ) 0.28 = only "fair agreement"; P < 0.001.Where documented, 77% (53/69) of patients with CD responded to induction; and 65% (46/71) entered remission. A total of 2287 infusions and 301.96 years of patient' follow-up (n = 385) are represented; adverse events affected 3% (49/1587) infliximab and 2% (2/98) adalimumab infusions (no deaths or malignancies). Peri-anal abscess drainage was less common after anti-TNF initiation (CD), that is 26% (27/102) before, 7% (3/42) after (P = 0.01); however, pre and post anti-TNF data collection was not over equal time periods. CONCLUSIONS: Anti-TNFs are effective treatments, usually given with thiopurine co-immunosuppression. This study highlights deficiencies in formal documentation of effect and disparity between disease severity scoring tools, which need to be addressed to improve ongoing patient care.

Matrix expansion and syncytial aggregation of syndecan-1+ cells underpin villous atrophy in coeliac disease.

BACKGROUND: We studied the expression of sulphated glycosaminoglycans (GAGs) in coeliac disease (CD) mucosa, as they are critical determinants of tissue volume, which increases in active disease. We also examined mucosal expression of IL-6, which stimulates excess GAG synthesis in disorders such as Grave's ophthalmopathy. METHODS: We stained archival jejunal biopsies from 5 children with CD at diagnosis, on gluten-free diet and challenge for sulphated GAGs. We then examined duodenal biopsies from 9 children with CD compared to 9 histological normal controls, staining for sulphated GAGs, heparan sulphate proteoglycans (HSPG), short-chain HSPG (Δ-HSPG) and the proteoglycan syndecan-1 (CD138), which is expressed on epithelium and plasma cells. We confirmed findings with a second monoclonal in another 12 coeliac children. We determined mucosal IL-6 expression by immunohistochemistry and PCR in 9 further cases and controls, and used quantitative real time PCR for other Th17 pathway cytokines in an additional 10 cases and controls. RESULTS: In CD, HSPG expression was lost in the epithelial compartment but contrastingly maintained within an expanded lamina propria. Within the upper lamina propria, clusters of syndecan-1(+) plasma cells formed extensive syncytial sheets, comprising adherent plasma cells, lysed cells with punctate cytoplasmic staining and shed syndecan ectodomains. A dense infiltrate of IL-6(+) mononuclear cells was detected in active coeliac disease, also localised to the upper lamina propria, with significantly increased mRNA expression of IL-6 and IL-17A but not IL-23 p19. CONCLUSIONS: Matrix expansion, through syndecan-1(+) cell recruitment and lamina propria GAG increase, underpins villous atrophy in coeliac disease. The syndecan-1(+) cell syncytia and excess GAG production recapitulate elements of the invertebrate encapsulation reaction, itself dependent on insect transglutaminase and glutaminated early response proteins. As in other matrix expansion disorders, IL-6 is upregulated and represents a logical target for immunotherapy in patients with coeliac disease refractory to gluten-free diet.

A comparison of outcomes for adults and children undergoing resection for inflammatory bowel disease: is there a difference?

Background. The incidence of inflammatory bowel disease (IBD) is increasing in the paediatric population. Since 2007, a single surgeon whose main practice is in the treatment of adults has performed surgery for IBD in adults and children within two dedicated multidisciplinary teams. Our aim was to assess and compare outcomes for adults and children following surgery for IBD. Methods. Analysis of a prospectively collected database was carried out to include all patients who had undergone resectional surgery for IBD between 2007 and 2012. Results. 48 adults and 30 children were included in the study. Median age for children was 14 years (range 8-16) and for adults was 33.5 years (range 17-64). Median BMI was 23 (range 18-38) and 19 (range 13-29.5) in adults and children, respectively (P < 0.001). Laparoscopic resection was performed in 27 (90%) children and 36 (75%) adults. Postoperative complication rates were comparable, 11 (23%) in adults versus 6 (20%) in children (P = 1.00). Conclusion. Resectional surgery for IBD in children has outcomes that compare favourably with the adult population, with the majority of cases being performed by a laparoscopic approach.

Intraepithelial lymphocyte eotaxin-2 expression and perineural mast cell degranulation differentiate allergic/eosinophilic colitis from classic IBD.

OBJECTIVES: Allergic colitis shows overlap with classic inflammatory bowel disease (IBD). Clinically, allergic colitis is associated with dysmotility and abdominal pain, and mucosal eosinophilia is characteristic. We thus aimed to characterise mucosal changes in children with allergic colitis compared with normal tissue and classic IBD, focusing on potential interaction between eosinophils and mast cells with enteric neurones. METHODS: A total of 15 children with allergic colitis, 10 with Crohn disease (CD), 10 with ulcerative colitis (UC), and 10 histologically normal controls were studied. Mucosal biopsies were stained for CD3 T cells, Ki-67, eotaxin-1, and eotaxin-2. Eotaxin-2, IgE, and tryptase were localised compared with mucosal nerves, using neuronal markers neurofilament protein, neuron-specific enolase, and nerve growth factor receptor. RESULTS: Overall inflammation was greater in patients with CD and UC than in patients with allergic colitis. CD3 T-cell density was increased in patients with allergic colitis, similar to that in patients with CD but lower than in patients with UC, whereas eosinophil density was higher than in all other groups. Eotaxin-1 and -2 were localised to basolateral crypt epithelium in all specimens, with eotaxin-1+ lamina propria cells found in all of the colitis groups. Eotaxin-2+ intraepithelial lymphocyte (IEL) density was significantly higher in allergic colitis specimens than in all other groups. Mast cell degranulation was strikingly increased in patients with allergic colitis (12/15) compared with that in patients with UC (1/10) and CD (0/1). Tryptase and IgE colocalised on enteric neurons in patients with allergic colitis but rarely in patients with IBD. CONCLUSIONS: Eotaxin-2+ IELs may contribute to the periepithelial eosinophil accumulation characteristic of allergic colitis. The colocalisation of IgE and tryptase with mucosal enteric nerves is likely to promote the dysmotility and visceral hyperalgesia classically seen in allergic gastrointestinal inflammation.

Enteric neural disruption in necrotizing enterocolitis occurs in association with myenteric glial cell CCL20 expression.

OBJECTIVE: The aetiology of necrotising enterocolitis (NEC) is unknown, but luminal factors and epithelial leakiness appear critical triggers of an inflammatory cascade. A separate finding has been suggested in mouse models, in which disruption of glial cells in the myenteric plexus induced a severe NEC-like lesion. We have thus looked for evidence of neuroglial abnormality in NEC. METHODS: We studied full-thickness resected specimens from 20 preterm infants with acute NEC and from 13 control infants undergoing resection for other indications. Immunohistochemical analysis was performed for immunological (CD3, syndecan-1, human leucocyte antigen-DR), neural (glial fibrillary acidic protein [GFAP], nerve growth factor receptor, neurofilament protein, neuron-specific enolase), and functional markers (Ki67), and for potential inflammatory regulators (interleukin-12, transforming growth factor-ß, CCL20, CCR6). RESULTS: Expression of the chemokine CCL20 and its receptor CCR6 was significantly upregulated in myenteric plexus in NEC, with CCL20 strongly expressed by glial cells. In 9 of 20 cases with NEC, myenteric plexus architecture and GFAP+ glial cells were normal, with preserved submucosal and mucosal innervation; however, 11 cases showed disrupted myenteric plexus architecture, reduced GFAP expression, and loss of submucosal and mucosal innervation. Persistent abnormalities were identified in the 2 infants who had ongoing inflammation at ileostomy closure. CONCLUSIONS: Our findings identified heterogeneity among patients with NEC. Approximately half showed evidence of marked neural abnormality extending from the deeper layers of the intestine, associated with glial activation and myenteric plexus disruption. The factors that may activate enteric glia in this manner, potentially including bacterial products or viruses, remain to be determined.

Single port laparoscopic subtotal colectomy and ileostomy in an adolescent with ulcerative colitis.

INTRODUCTION: Single port laparoscopic surgery has been increasingly used for complex surgical procedures. To our knowledge, this is the first published report of a single port laparoscopic subtotal colectomy and ileostomy in an adolescent patient with ulcerative colitis. CASE REPORT: A 13-year old female patient with ulcerative colitis resistant to maximal medical therapy underwent a single port laparoscopic subtotal colectomy and ileostomy. Both the procedure and the postoperative recovery were uneventful and the patient was discharged home on the sixth postoperative day. Follow-up at 3 and 8 weeks after surgery identified no early complications with a 4 kg weight gain. DISCUSSION: Single port laparoscopic surgery is feasible in the adolescent population if there is appropriate surgical expertise and strict patient selection.

Enterotoxin-producing staphylococci cause intestinal inflammation by a combination of direct epithelial cytopathy and superantigen-mediated T-cell activation.

BACKGROUND: Enterotoxin-producing Staphylococcus aureus may cause severe inflammatory intestinal disease, particularly in infants or immunodeficient or elderly patients. They are also recognized to be associated with sudden infant death syndrome. Little is known, however, about mucosal responses to staphylococci. METHODS: The mucosal lesion in three infants with staphylococcal enterocolitis was assessed by immunohistochemistry and electron microscopy. The organisms underwent extensive molecular analysis. Their toxins were assessed for capacity to induce T-cell activation and host mucosal responses examined by in vitro organ culture. Epithelial responses were studied by coculture with HEp-2 and Caco-2 cells. RESULTS: Intestinal biopsies from the patients showed marked epithelial damage with mucosal inflammation. The three staphylococci, representing two distinct clones, were methicillin-sensitive, producing SEG/I enterotoxins and Rho-inactivating EDIN toxins. Their enterotoxins potently activated T cells, but only whole organisms could induce in vitro enteropathy, characterized by remarkable epithelial desquamation uninhibited by tacrolimus. EDIN-producing staphylococci, but not their supernatants, induced striking cytopathy in HEp-2 epithelial cells but not in Caco-2 cells. Although HEp-2 and Caco-2 cells produced similar IL-8, CCL20, and cathelicidin LL37 responses upon bacterial exposure, only Caco-2 cells expressed mRNA for the ß-defensins HBD2 and HBD3, while HEp-2 cells were unable to do so. CONCLUSIONS: Staphylococci induce enterocolitis by a combination of direct enterocyte cytopathy mediated by EDIN toxins, disrupting the epithelial barrier, and enterotoxin superantigen-induced mucosal T-cell activation. Gut epithelial production of ß-defensins may contribute to host defense against invasive staphylococcal disease.

Feasibility of a finger prick-based self-testing kit in first- and second-degree relatives of children with coeliac disease.

AIM: To assess feasibility of a finger prick-based kit as method for self-testing of first and second-degree relatives of coeliac disease (CD) patients. METHODS: A total number of 379 subjects were invited to participate in this study, consisting of 197 first-degree and 182 second-degree relatives of CD patients. The self-testing kit (Biocard™) was sent out with included instructions for use. Completed tests were sent back to the study coordinator for assessment. RESULTS: One hundred and ninety-six invited relatives carried out the Biocard™ test at home. Amongst these, 70% were children. In 97% of the cases the test was performed correctly. Three tests revealed a positive result, all of which were later confirmed by serology and histology as coeliac disease. CONCLUSION: Our study indicates that Biocard™ test is a reliable, easy to use and well-accepted tool for home testing of first- and second-degree relatives of CD patients.

Expression of human beta-defensins in children with chronic inflammatory bowel disease.

BACKGROUND: 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. METHODS: 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. RESULTS: 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. CONCLUSION: 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.