British Society of Gastroenterology (BSG) and British Society of Paediatric Gastroenterology, Hepatology and Nutrition (BSPGHAN) joint consensus guidelines on the diagnosis and management of eosinophilic oesophagitis in children and adults.

BACKGROUND: Eosinophilic oesophagitis (EoE) is an increasingly common cause of dysphagia in both children and adults, as well as one of the most prevalent oesophageal diseases with a significant impact on physical health and quality of life. We have provided a single comprehensive guideline for both paediatric and adult gastroenterologists on current best practice for the evaluation and management of EoE. METHODS: The Oesophageal Section of the British Society of Gastroenterology was commissioned by the Clinical Standards Service Committee to develop these guidelines. The Guideline Development Group included adult and paediatric gastroenterologists, surgeons, dietitians, allergists, pathologists and patient representatives. The Population, Intervention, Comparator and Outcomes process was used to generate questions for a systematic review of the evidence. Published evidence was reviewed and updated to June 2021. The Grading of Recommendations, Assessment, Development and Evaluation (GRADE) system was used to assess the evidence and make recommendations. Two rounds of voting were held to assess the level of agreement and the strength of recommendations, with 80% consensus required for acceptance. RESULTS: Fifty-seven statements on EoE presentation, diagnosis, investigation, management and complications were produced with further statements created on areas for future research. CONCLUSIONS: These comprehensive adult and paediatric guidelines of the British Society of Gastroenterology and British Society of Paediatric Gastroenterology, Hepatology and Nutrition are based on evidence and expert consensus from a multidisciplinary group of healthcare professionals, including patient advocates and patient support groups, to help clinicians with the management patients with EoE and its complications.

International Consensus Recommendations for Eosinophilic Gastrointestinal Disease Nomenclature.

BACKGROUND & AIMS: Substantial heterogeneity in terminology used for eosinophilic gastrointestinal diseases (EGIDs), particularly the catchall term "eosinophilic gastroenteritis," limits clinical and research advances. We aimed to achieve an international consensus for standardized EGID nomenclature. METHODS: This consensus process utilized Delphi methodology. An initial naming framework was proposed and refined in iterative fashion, then assessed in a first round of Delphi voting. Results were discussed in 2 consensus meetings, and the framework was updated and reassessed in a second Delphi vote, with a 70% threshold set for agreement. RESULTS: Of 91 experts participating, 85 (93%) completed the first and 82 (90%) completed the second Delphi surveys. Consensus was reached on all but 2 statements. "EGID" was the preferred umbrella term for disorders of gastrointestinal (GI) tract eosinophilic inflammation in the absence of secondary causes (100% agreement). Involved GI tract segments will be named specifically and use an "Eo" abbreviation convention: eosinophilic gastritis (now abbreviated EoG), eosinophilic enteritis (EoN), and eosinophilic colitis (EoC). The term "eosinophilic gastroenteritis" is no longer preferred as the overall name (96% agreement). When >2 GI tract areas are involved, the name should reflect all of the involved areas. CONCLUSIONS: This international process resulted in consensus for updated EGID nomenclature for both clinical and research use. EGID will be the umbrella term, rather than "eosinophilic gastroenteritis," and specific naming conventions by location of GI tract involvement are recommended. As more data are developed, this framework can be updated to reflect best practices and the underlying science.

Management of eosinophilic esophagitis associated food impaction in Europe and the United States.

Eosinophilic esophagitis (EoE) is the most common cause of esophageal food impaction (EFI). Approaches to management of EFI due to EoE have not been well characterized. We conducted a web-based survey to understand approaches to management of EFI due to EoE among endoscopists. Questions focused on management of patients from presentation to post-endoscopy follow-up. The survey was administered to a list of eligible candidates provided by societies of gastroenterology. A total of 308 endoscopists completed the questionnaire. The majority (83%) practiced in Europe and treated adults (78%). Most agreed patients should be advised to seek emergency care (66%) within 1 to 2 hours (41% agreement). There was agreement that medications to induce vomiting should be avoided (84%) and that blood tests or imaging studies were usually not required before endoscopy. By contrast, there was more variability in the type of sedation recommended and the need for endotracheal intubation, especially when comparing more experienced with less experienced EoE-endoscopists. Overall, fewer than half (43%) respondents recommended obtaining esophageal biopsies during the initial endoscopy. However, there were significant differences in the proportion who recommended biopsies based on level of EoE-experience (25, 52, 77%, P < 0.001; less vs. moderate vs. very experienced) and comparing pediatric and adult endoscopists (32, vs. 79%, P < 0.001; adult vs. pediatric). There exists heterogeneity among endoscopists in recommendations to manage EFI in patients with EoE. These findings support development of clinical guidelines and new studies to clarify the rationale for best practices. Key summary: Established knowledge-The optimal management of patients with esophageal food impaction due to eosinophilic esophagitis from presentation at the emergency department to postendoscopy care is unclear. New findings-Considerable recommendation variation exists in the management of EFI in patients with EoE. Our findings provide a rationale for the creation of consensus practice guidelines and further study into best practices.

Pediatric Eosinophilic Esophagitis: Results of the European Retrospective Pediatric Eosinophilic Esophagitis Registry (RetroPEER).

OBJECTIVES: Recommendations for diagnosing and treating eosinophilic esophagitis (EoE) are evolving; however, information on real world clinical practice is lacking. To assess the practices of pediatric gastroenterologists diagnosing and treating EoE and to identify the triggering allergens in European children. METHODS: Retrospective anonymized data were collected from 26 European pediatric gastroenterology centers in 13 countries. Inclusion criteria were: Patients diagnosis with EoE, completed investigations prescribed by the treating physician, and were on stable medical or dietary interventions. RESULTS: In total, 410 patients diagnosed between December 1999 and June 2016 were analyzed, 76.3% boys. The time from symptoms to diagnosis was 12 ±â€Š33.5 months and age at diagnosis was 8.9 ±â€Š4.75 years. The most frequent indications for endoscopy were: dysphagia (38%), gastroesophageal reflux (31.2%), bolus impaction (24.4%), and failure to thrive (10.5%). Approximately 70.3% had failed proton pump inhibitor treatment. The foods found to be causative of EoE by elimination and rechallenge were milk (42%), egg (21.5%), wheat/gluten (10.9%), and peanut (9.9%). Elimination diets were used exclusively in 154 of 410 (37.5%), topical steroids without elimination diets in 52 of 410 (12.6%), both diet and steroids in 183 of 410 (44.6%), systemic steroids in 22 of 410 (5.3%), and esophageal dilation in 7 of 410 (1.7%). Patient refusal, shortage of endoscopy time, and reluctance to perform multiple endoscopies per patient were noted as factors justifying deviation from guidelines. CONCLUSIONS: In this "real world" pediatric European cohort, milk and egg were the most common allergens triggering EoE. Although high-dose proton pump inhibitor trials have increased, attempted PPI treatment is not universal.

Validation of Antibody-Based Strategies for Diagnosis of Pediatric Celiac Disease Without Biopsy.

BACKGROUND & AIMS: A diagnosis of celiac disease is made based on clinical, genetic, serologic, and duodenal morphology features. Recent pediatric guidelines, based largely on retrospective data, propose omitting biopsy analysis for patients with concentrations of IgA against tissue transglutaminase (IgA-TTG) >10-fold the upper limit of normal (ULN) and if further criteria are met. A retrospective study concluded that measurements of IgA-TTG and total IgA, or IgA-TTG and IgG against deamidated gliadin (IgG-DGL) could identify patients with and without celiac disease. Patients were assigned to categories of no celiac disease, celiac disease, or biopsy required, based entirely on antibody assays. We aimed to validate the positive and negative predictive values (PPV and NPV) of these diagnostic procedures. METHODS: We performed a prospective study of 898 children undergoing duodenal biopsy analysis to confirm or rule out celiac disease at 13 centers in Europe. We compared findings from serologic analysis with findings from biopsy analyses, follow-up data, and diagnoses made by the pediatric gastroenterologists (celiac disease, no celiac disease, or no final diagnosis). Assays to measure IgA-TTG, IgG-DGL, and endomysium antibodies were performed by blinded researchers, and tissue sections were analyzed by local and blinded reference pathologists. We validated 2 procedures for diagnosis: total-IgA and IgA-TTG (the TTG-IgA procedure), as well as IgG-DGL with IgA-TTG (TTG-DGL procedure). Patients were assigned to categories of no celiac disease if all assays found antibody concentrations <1-fold the ULN, or celiac disease if at least 1 assay measured antibody concentrations >10-fold the ULN. All other cases were considered to require biopsy analysis. ULN values were calculated using the cutoff levels suggested by the test kit manufacturers. HLA typing was performed for 449 participants. We used models that considered how specificity values change with prevalence to extrapolate the PPV and NPV to populations with lower prevalence of celiac disease. RESULTS: Of the participants, 592 were found to have celiac disease, 345 were found not to have celiac disease, and 24 had no final diagnosis. The TTG-IgA procedure identified patients with celiac disease with a PPV of 0.988 and an NPV of 0.934; the TTG-DGL procedure identified patients with celiac disease with a PPV of 0.988 and an NPV of 0.958. Based on our extrapolation model, we estimated that the PPV and NPV would remain >0.95 even at a disease prevalence as low as 4%. Tests for endomysium antibodies and HLA type did not increase the PPV of samples with levels of IgA-TTG ≥10-fold the ULN. Notably, 4.2% of pathologists disagreed in their analyses of duodenal morphology-a rate comparable to the error rate for serologic assays. CONCLUSIONS: In a prospective study, we validated the TTG-IgA procedure and the TTG-DGL procedure in identification of pediatric patients with or without celiac disease, without biopsy. German Clinical Trials Registry no.: DRKS00003854.

Antibody Concentrations Decrease 14-Fold in Children With Celiac Disease on a Gluten-Free Diet but Remain High at 3 Months.

BACKGROUND & AIMS: Celiac disease can be identified by a serologic test for IgA against tissue transglutaminase (IgA-TTG) in a large proportion of children. However, the increased concentrations of antibody rarely normalize within the months after children are placed on a gluten-free diet (GFD). Early serologic predictors of sufficient adherence to GFD are required for optimal treatment. METHODS: In a prospective study, we observed the response to a GFD in 345 pediatric patients (67% girls; mean age, 8.4 y) who underwent duodenal biopsy to confirm or refute celiac disease from October 2012 through December 2015. Baseline serum samples were tested centrally for IgA-TTG and IgG against deamidated gliadin. Follow-up serologic analyses of children on a GFD were performed about 3 months later. RESULTS: The geometric mean concentration of IgA-TTG decreased from 72.4-fold to 5.2-fold the upper limit of normal (ULN), or by a factor of 14.0 (95% CI, 12.0-16.4). A substantial response (defined as a larger change than the typical variation in patients not on a GFD) was observed in 80.6% of the children. Only 28.1% of patients had a substantial response in the concentration of IgG against deamidated gliadin. Concentration of IgA-TTG remained above 1-fold the ULN in 83.8% of patients, and above 10-fold the ULN in 26.6% of patients with a substantial response. CONCLUSIONS: Serum concentration of IgA-TTG decreases substantially in most children with celiac disease within 3 months after they are placed on a GFD, but does not normalize in most. This information on changes in antibody concentrations can be used to assess patient response to the diet at short-term follow-up evaluations. Patients with a substantial response to a GFD often still have high antibody levels after 3 months. German Clinical Trials Registry no. DRKS00003854.

Use of Infliximab Biosimilar Versus Originator in a Pediatric United Kingdom Inflammatory Bowel Disease Induction Cohort.

OBJECTIVES: The aim of the study was to summarize short-term effectiveness, safety, and cost of using infliximab biosimilar (IFX-B) drugs, (Inflectra [Hospira] and Remsima [NAAP]) compared to originator infliximab (IFX-O) (Remicade [MSD]) in biologic naive pediatric inflammatory bowel disease in the United Kingdom. METHODS: Prospective audit of patients starting anti-tumour necrosis factor (TNF) therapy. Disease severity, response to treatment, and remission rate was measured by Pediatric Crohn's Disease Activity Index (PCDAI) and/or Physician Global Assessment. RESULTS: Between March 2015 and February 2016, 278 patients (175 IFX-O, 82 IFX-B, and 21 Adalimumab) were started on anti-TNF therapy. This was compared with collected data on 398 patients started on IFX-O from 2011 to 2015. At initiation, median PCDAI was 36 (20,48) (n = 42) in the IFX-O group and 28 (20,40) (n = 29) in the IFX-B group, (P = 0.08). Immunosuppression rates were similar: 150/175 (86%) for IFX-O and 65/82 (79%) for IFX-B (P > 0.05). Post induction, median PCDAI score was 5 (0,11) (n = 19) and 0 (0,8) (n = 15) in the IFX-O and IFX-B groups, respectively (P = 0.35). There was no difference in response to treatment using Physician Global Assessment 85% (n = 28) in IFX-O group and 86% (n = 19) in IFX-B group (P > 0.05). Adverse events at initiation and post induction were not different between both groups (P > 0.05). Using conservative calculations, £875,000 would have been saved for a 1-year period with universal adoption of biosimilars in patients who were instead treated with IFX-O. CONCLUSIONS: IFX-B is likely as effective as IFX-O in treating IBD in comparable pediatric populations. Sites should adopt infliximab biosimilar for new starts due to cost reduction with no difference in other parameters.

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.

Clinical Experience of Use of High-dose Intravenous Methylprednisolone in Children With Acute Moderate to Severe Colitis.

OBJECTIVES: Treatment of acute severe colitis (ASC) has been associated with high morbidity and high colectomy rate in children. In the prebiologics era, our centre used short-term high-dose intravenous corticosteroids (IVCS) at 2 to 30 mg ·â€Škg ·â€Šday. We conducted a retrospective review to compare efficacy of different dosing regimes of IVCS. METHODS: Thirty-four children treated with IVCS for ASC were included over 8 years. Patients were studied as 2 groups with similar pretreatment patient characteristics. Group 1 (standard dose) received IVCS at 2 mg ·â€Škg ·â€Šday and group 2 (high dose) received IVCS at 10 to 30 mg ·â€Škg ·â€Šday. Safety, efficacy, and follow-up of the entire cohort for >1 year were studied. The median IVCS dose in the standard- and high-dose cohort was 1.5 mg ·â€Škg ·â€Šday (maximum 60 mg ·â€Škg ·â€Šday) and 24.8 mg ·â€Škg ·â€Šday (maximum 1000 mg ·â€Škg ·â€Šday), respectively. RESULTS: Pediatric Ulcerative Colitis Activity Index scores at day 5 were significantly lower in high-dose (15, interquartile range 8.5-20) than in standard-dose IVCS (30, interquartile range 20-30). IVCS side effects were minor and reversible. Overall, medical salvage therapy was required in 5.8% (2 children) before discharge, and in 17% (6 children) at follow-up after 1 year. The colectomy rate of the entire cohort was remarkably low with 0% during admission and 11% (4 children) after 1 year, with a trend of less colectomies in high-dose (4.8%-1 child) than in standard-dose (23%-3 children). CONCLUSIONS: Our data show that in paediatric ASC, the short-term use of high-dose IVCS is safe and effective. Prospective studies are needed to define the role of IVCS within salvage therapy protocols.

Corticosteroid Dosing in Pediatric Acute Severe Ulcerative Colitis: A Propensity Score Analysis.

OBJECTIVES: We aimed to explore the optimal dosing of intravenous-corticosteroids (IVCS) using a robust statistical method on the largest pediatric cohort of acute severe colitis to date. METHODS: Two hundred eighty-three children treated with IVCS for ulcerative colitis were included and studied for 1 year (46% boys, age 12.1 ±â€Š3.9 years, disease duration 2 (interquartile range [IQR] 0-14) months, baseline Pediatric Ulcerative Colitis Activity Index 69 ±â€Š13 points). Confounding by indication was addressed by matching high- and low-IVCS dose patients according to the propensity score method, using 3 cutoffs (1 mg ·â€Škg ·â€Šmethylprednisolone to 40 mg ·â€Šday, 1.25 mg ·â€Škg to 50 mg ·â€Šday and 2 mg ·â€Škg to 80 mg ·â€Šday). RESULTS: The median IVCS dose in the entire cohort was 1.0 mg ·â€Škg ·â€Šday (IQR 0.8-1.4) and 44 mg ·â€Škg ·â€Šday (32-60). Ninety-four of 283 children were matched in the low-dose cutoff (1 mg ·â€Škg ·â€Šday), 218 of 283 were matched in the middle cutoff (1.25 mg ·â€Škg ·â€Šday), and 86/283 in the high dose cutoff (2 mg ·â€Škg ·â€Šday). No differences were found in 25 pretreatment baseline variables in the three cutoffs, implying successful matching. There were no statistical differences in the outcomes of the two lower cutoffs (including need for salvage therapy during admission and by 1 years, admission duration, and day-5 Pediatric Ulcerative Colitis Activity Index<35 points; all P > 0.05). In the high cutoff, the higher doses were somewhat better but this benefit reversed in a sensitivity analysis excluding one center. High doses were not associated with better outcome also in a propensity score-weighted regression model on the entire cohort. CONCLUSIONS: Our data support present guidelines that doses of IVCS >1 to 1.5 mg ·â€Škg ·â€Šday (maximum 40-60 mg ·â€Škg ·â€Šday) are not justified in acute severe colitis.

Physical activity, cardiorespiratory fitness, and clustered cardiometabolic risk in 10- to 12-year-old school children: the REACH Y6 study.

OBJECTIVES: (1) Investigate whether clustered cardiometabolic risk score, cardiorespiratory fitness (CRF), sedentary time (ST), and body mass index Z-scores (BMI Z-scores), differed between participants that met and did not achieve ≥60 min of daily moderate to vigorous intensity physical activity (MVPA). (2) Compare clustered cardiometabolic risk score, BMI Z-score, ST, and MVPA by CRF status. METHODS: One hundred and one (n = 45 boys) 10- to 12-year-old participants took part in this cross-sectional study, conducted in Liverpool (Summer 2010) and Ulster (Spring 2011) UK. Assessments of blood markers, stature, sitting stature, body mass, waist circumference, flow mediated dilation (FMD), and resting blood pressure (BP) were completed. CRF (VO2 peak) was estimated using an individually calibrated treadmill protocol. Habitual MVPA and ST were assessed using an individually calibrated accelerometer protocol. Clustered cardiometabolic risk scores were calculated using blood markers, FMD (%), BP and anthropometric measures. Participants were classified as active (≥60 min MVPA) or inactive and as fit or unfit. Multivariate analysis of covariance (MANCOVA) was used to investigate differences in cardiometabolic risk, BMI Z-score, CRF, and ST by activity status. MANCOVA was also completed to assess differences in cardiometabolic risk, MVPA, ST, and BMI Z-score by fitness status. RESULTS: Inactive children exhibited significantly higher clustered cardiometabolic risk scores and ST, and lower CRF than active children. Unfit participants exhibited significantly higher clustered cardiometabolic risk scores, BMI Z-scores and ST and lower MVPA in comparison to fit participants. CONCLUSIONS: This study highlights the importance of children achieving 60 min MVPA daily and provides further evidence surrounding the importance of CRF for health.

Swallowed topical steroid therapy for eosinophilic oesophagitis in children: practical, evidence-based guidance by the BSPGHAN Eosinophilic Oesophagitis Working Group.

OBJECTIVE: To develop evidence-based guidance for topical steroid use in paediatric eosinophilic oesophagitis (pEoE) in the UK for both induction and maintenance treatment. METHODS: A systematic literature review using Cochrane guidance was carried out by the British Society of Paediatric Gastroenterology, Hepatology and Nutrition (BSPGHAN) Eosinophilic Oesophagitis (EoE) Working Group (WG) and research leads to determine the evidence base for preparation, dosing and duration of use of swallowed topical steroid (STS) formulations in EoE. Seven themes relating to pEoE were reviewed by the WG, alongside the Cochrane review this formed the evidence base for consensus recommendations for pEoE in the UK. We provide an overview of practical considerations including treatment regimen and dosing. Oral viscous budesonide (OVB) and, if agreed by local regulatory committees, orodispersible budesonide (budesonide 1 mg tablets) were selected for ease of use and with most improvement in histology. A practical 'how to prepare and use' OVB appendix is included. Side effects identified included candidiasis and adrenal gland suppression. The use of oral systemic steroids in strictures is discussed briefly. RESULTS: 2638 citations were identified and 18 randomised controlled trials were included. Evidence exists for the use of STS for induction and maintenance therapy in EoE, especially regarding histological improvement. Using the Appraisal of Guidelines, Research and Evaluation criteria, dosing of steroids by age (0.5 mg two times per day <10 years and 1 mg two times per day ≥10 years) for induction of at least 3 months was suggested based on evidence and practical consideration. Once histological remission is achieved, maintenance dosing of steroids appears to reduce the frequency and severity of relapse, as such a maintenance weaning regimen is proposed. CONCLUSION: A practical, evidence-based flow chart and guidance recommendations with consensus from the EoE WG and education and research representatives of BSPGHAN were developed with detailed practical considerations for use in the UK.

Somatic mosaicism and common genetic variation contribute to the risk of very-early-onset inflammatory bowel disease.

Very-early-onset inflammatory bowel disease (VEO-IBD) is a heterogeneous phenotype associated with a spectrum of rare Mendelian disorders. Here, we perform whole-exome-sequencing and genome-wide genotyping in 145 patients (median age-at-diagnosis of 3.5 years), in whom no Mendelian disorders were clinically suspected. In five patients we detect a primary immunodeficiency or enteropathy, with clinical consequences (XIAP, CYBA, SH2D1A, PCSK1). We also present a case study of a VEO-IBD patient with a mosaic de novo, pathogenic allele in CYBB. The mutation is present in ~70% of phagocytes and sufficient to result in defective bacterial handling but not life-threatening infections. Finally, we show that VEO-IBD patients have, on average, higher IBD polygenic risk scores than population controls (99 patients and 18,780 controls; P < 4 × 10-10), and replicate this finding in an independent cohort of VEO-IBD cases and controls (117 patients and 2,603 controls; P < 5 × 10-10). This discovery indicates that a polygenic component operates in VEO-IBD pathogenesis.

Autocrine stimulation of human hepatocytes triggers late DNA synthesis and stabilizes long-term differentiation in vitro.

Isolated human hepatocytes are of great value in investigating cell transplantation, liver physiology, pathology, and drug metabolism. Though hepatocytes possess a tremendous proliferative capacity in vivo, their ability to grow in culture is severely limited. We postulated that repeated medium change, common to most in vitro systems, may prevent long-term maintenance of hepato-specific functions and growth capacity. To verify our hypotheses we compared the DNA synthesis and differentiation status of isolated human hepatocytes, cultured in medium which was renewed every day or was not changed for 3 weeks ('autocrine' setting). Daily medium change led to rapid hepatocellular de-differentiation without any signs of DNA replication. In contrast, the autocrine setting allowed hepatocytes to become highly differentiated, demonstrated by an elevated ASGPr expression level, and increased albumin and fibrinogen synthesis and release. Cytokeratin 18 filaments were stably expressed, whereas cytokeratin 19 remained undetectable. Hepatocytes growing in an autocrine fashion were activated in the presence of hepatocyte growth factor (HGF), evidenced by c-Met phosphorylation. However, HGF response was not achieved when the culture medium was renewed daily. Furthermore, the autocrine setting evoked a late but strong interleukin 6 release into the culture supernatant, reaching maximum values after a 10-day cultivation period, and intense BrdU incorporation after a further 5-day period. Our data suggest that preservation of the same medium creates environmental conditions which allow hepatocytes to control their differentiation status and DNA synthesis in an autocrine fashion. Further studies are necessary to identify the key mediators involved in autocrine communication and to design the optimal culture configuration for clinical application.

BSPGHAN Motility Working Group position statement: paediatric multichannel intraluminal pH impedance monitoring-indications, methods and interpretation.

BACKGROUND: Combined pH-impedance monitoring has been suggested as the investigation of choice for diagnosing gastro-oesophageal reflux in children. Although it is superior to oesophageal pH monitoring in detecting all types of reflux episodes (acid, weakly acidic and alkaline) with the ability to evaluate symptom association with reflux events, it is still limited by the lack of true paediatric normal value and the high cost involved (equipment and personnel). OBJECTIVE: To produce a position statement on behalf of the Motility Working Group of the British Society of Paediatric Gastroenterology, Hepatology and Nutrition on the indications and practical application of combined oesophageal pH-impedance monitoring in children. METHODS: Up-to-date review of available evidence. RESULTS: This document provides a practical guide to clinician on indications, methods and results interpretation of paediatric multichannel intraluminal impedance pH (MII-pH). CONCLUSIONS: MII-pH is increasingly used by paediatricians as the diagnostic tool for assessing gastro-oesophageal reflux disease and symptom association. There is wide variation in paediatric practice and a need for standardised practice.

Controlled and reversible induction of differentiation and activation of adult human hepatocytes by a biphasic culture technique.

AIM: Clinical application of human hepatocytes (HC) is hampered by the progressive loss of growth and differentiation in vitro. The object of the study was to evaluate the effect of a biphasic culture technique on expression and activation of growth factor receptors and differentiation of human adult HC. METHODS: Isolated HC were sequentially cultured in a hormone enriched differentiation medium (DM) containing nicotinamide, insulin, transferrin, selenium, and dexame-thasone or activation medium (AM) containing hepatocyte growth factor (HGF), epidermal growth factor (EGF), and granulocyte-macrophage colony-stimulating factor (GM-CSF). Expression, distribution and activation of the HC receptors (MET and EGFR) and the pattern of characteristic cytokeratin (CK) filaments were measured by fluorometry, confocal microscopy and Western blotting. RESULTS: In the biphasic culture system, HC underwent repeated cycles of activation (characterized by expression and activation of growth factor receptors) and re-differentiation (illustrated by distribution of typical filaments CK-18 but low or absent expression of CK-19). In AM increased expression of MET and EGFR was associated with receptor translocation into the cytoplasm and induction of atypical CK-19. In DM low expression of MET and EGFR was localized on the cell membrane and CK-19 was reduced. Receptor phosphorylation required embedding of HC in collagen type I gel. CONCLUSION: Control and reversible modulation of growth factor receptor activation of mature human HC can be accomplished in vitro, when defined signals from the extracellular matrix and sequential growth stimuli are provided. The biphasic technique helps overcome de-differentiation, which occurs during continuous stimulation by means of growth factors.

Phosphorylation of hepatocyte growth factor receptor and epidermal growth factor receptor of human hepatocytes can be maintained in a (3D) collagen sandwich culture system.

In vitro culture models that employ human liver cells could be potent tools for predictive studies on drug toxicity and metabolism in the pharmaceutical industry. However, an adequate receptor responsiveness is necessary to allow intracellular signalling and metabolic activity. We tested the ability of three-dimensionally arranged human hepatocytes to respond to the growth factors hepatocyte growth factor (HGF) or epidermal growth factor (EGF). Isolated adult human hepatocytes were cultivated within a three-dimensional collagen gel (sandwich) or on a two-dimensional collagen matrix. Cells were treated with HGF or EGF and expression and phosphorylative activity of HGF receptors (HGFr, c-met) or EGF receptors (EGFr) were measured by flow cytometry and Western blot. Increasing HGFr and EGFr levels were detected in hepatocytes growing two-dimensionally. However, both receptors were not activated in presence of growth factors. In contrast, when hepatocytes were plated within a three-dimensional matrix, HGFr and EGFr levels remained constantly low. However, both receptors became strongly phosphorylated by soluble HGF or EGF. We conclude that cultivation of human hepatocytes in a three-dimensionally arranged in vitro system allows the maintenance of specific functional activities. The necessity of cell dimensionality for HGFr and EGFr function should be considered when an adequate in vitro system has to be introduced for drug testing.