Efficacy of infliximab after loss of response of/intolerance to adalimumab in pediatric Crohn's disease: A retrospective multicenter cohort study of the "GETAID pédiatrique".

BACKGROUND: Infliximab (IFX) and adalimumab (ADA) are recommended for induction and maintenance of remission in pediatric Crohn's disease (CD). ADA is now often used in first line due to its efficacy and tolerability, but a loss of response (LOR) can occur over time. The aim was to assess the efficacy of IFX as second line therapy after LOR or intolerance to ADA in pediatric CD patients at 1 year. METHODS: We conducted a retrospective and multicenter study in France among the "GETAID pédiatrique" centers between April 2019 and April 2022. CD patients under 18 years old and treated with IFX after ADA failure or intolerance were included. We collected anthropometric, clinical, and biological data at baseline (start of IFX), at 6 and 12 months. Clinical remission was defined by a Weighted Pediatric CD Activity Index (wPCDAI) score less than 12.5 points. RESULTS: Of the 32 patients included in our study, 27 (84.4%) were still on IFX at 12 months of the switch. Among them, 13 had discontinued ADA because of a LOR, 12 for insufficient response and 2 due to primary nonresponse. At M12, 22 patients were in corticosteroid free clinical remission (68.7%). Under IFX, the wPCDAI decreased over time (47.5 ± 24.1, 16.6 ± 21.2 and 9.7 ± 19.0 at M0, M6 and M12 respectively). The only factor associated with clinical remission at 12 months was absence of perianal disease at the end of the IFX induction. CONCLUSIONS: IFX is effective in maintaining remission at 1 year in pediatric CD patients experiencing a LOR or intolerance with ADA, and IFX could be an interesting therapeutic choice instead of other biologics in this situation.

Risk factors for surgery in stricturing small bowel Crohn's disease: A retrospective cohort study from the GETAID pédiatrique.

OBJECTIVES: Previous studies have shown rates of surgical resection of up to 41% in stricturing pediatric Crohn's disease (CD). In this retrospective multicenter study, our aims were to identify clinical risk factors and magnetic resonance enterography (MRE) features of small bowel strictures associated with surgery. METHODS: Pediatric patients with symptomatic stricturing small bowel CD (defined as obstructive symptoms or proximal dilatation on MRE) confirmed by MRE between 2010 and 2020 were recruited from 12 French tertiary hospitals. Patient characteristics were compared by surgical outcome multivariable Cox regression. RESULTS: Fifty-six patients (61% boys) aged 12.2 ± 2.7 years at diagnosis of CD were included. Median duration of CD before diagnosis of stricture was 11.7 months (interquartile range [IQR]: 25-75: 1.2-29.9). Nineteen (34%) patients had stricturing phenotype (B2) at baseline. Treatments received  before stricture diagnosis included MODULEN-IBD (n = 31), corticosteroids (n = 35), antibiotics (n = 10), anti-TNF (n = 27), immunosuppressants (n = 28). Thirty-six patients (64%) required surgery, within 4.8 months (IQR: 25-75: 1.8-17.3) after stricture diagnosis. Parameters associated with surgical resection were antibiotic exposure before stricture diagnosis (adjusted odds ratio [aOR]: 15.62 [3.35-72.73], p = 0.0005), Crohn's disease obstructive symptoms score (CDOS) > 4 (aOR: 3.04 [1.15-8.03], p = 0.02) and dilation proximal to stricture >28 mm (aOR: 3.62 [1.17-11.20], p = 0.03). CONCLUSION: In this study, antibiotic treatment before stricture diagnosis, intensity of obstructive symptoms, and diameter of dilation proximal to small bowel stricture on MRE were associated with risk for surgical resection.

Adalimumab Therapy in Pediatric Crohn Disease: A 2-Year Follow-Up Comparing "Top-Down" and "Step-Up" Strategies.

OBJECTIVES: European Crohn's Colitis Organization (ECCO) and the European Society of Pediatric Gastroenterology, Hepatology and Nutrition (ESPGHAN) guidelines recommend the early use of anti-tumor necrosis factor (TNF) biologicals in pediatric Crohn disease (CD) patients with positive predictors for poor outcome. The objective of the present study was to compare early "Top-Down" use of adalimumab (ADA) immunomodulator/biologics-naive patients to conventional "Step-Up" management. METHODS: One hundred and twenty consecutive patients with a confirmed diagnosis of CD and treated with ADA between 2008 and 2019 were included and allocated to the ADA-Top Down (n = 59) or ADA-Step Up group (n = 61). The primary endpoint was prolonged steroid-/enteral nutrition-free clinical remission at 24 months, defined by a weighted Pediatric Crohn's Disease Activity Index (wPCDAI) < 12.5. Clinical and biological data were collected at 12 and 24 months. RESULTS: At start of ADA, disease activity was comparable between the ADA-Top Down group and the ADA-Step Up group (wPCDAI = 31 ± 16 vs 31.3 ± 15.2, respectively, P = 0.84). At 24 months, the remission rate was significantly higher in the ADA-Top Down group (73% vs 51%, P < 0.01). After propensity score, the Top-Down strategy is still more effective than the Step-Up strategy in maintaining remission at 24 months [hazard ratio (HR) = 0.36, 95% CI (0.15-0.87), P = 0.02]. Patients in the ADA-Top Down group were mainly on monotherapy compared to patients in the ADA-Step Up group (53/55 vs 28/55 respectively, P < 0.001). Serum levels of ADA were higher in the ADA-Top Down group than in the ADA-Step Up group (12.8 ± 4.3 vs 10.4 ± 3.9 µg/mL, respectively, P < 0.01). There were no serious adverse events. CONCLUSIONS: Early use of ADA appears to be more effective in maintaining relapse-free remission at 2 years, while using it as monotherapy. These findings further favor the recommendation of early anti-TNF use in high-risk CD patients.

Ustekinumab Use in Pediatric Inflammatory Bowel Disease: A French Multicenter Study From the Pediatric GETAID.

OBJECTIVES: Ustekinumab is known to be efficient in adult patients suffering from moderate to severe Crohn disease (CD) and ulcerative colitis (UC) resistant to anti-tumor necrosis factor-alpha (TNF-α). Here, we described the clinical course of treatment with ustekinumab in French pediatric inflammatory bowel disease (IBD) patients treated with ustekinumab. METHODS: This study includes all pediatric patients treated by ustekinumab injection for IBD (CD and UC), between January 2016 and December 2019. RESULTS: Fifty-three patients were enrolled, 15 males and 38 females. Forty-eight patients (90%) had a diagnosis of CD and 5 (9.4%) had UC. Sixty-five percent of CD patients presented an ileocolitis. Perineal disease was observed in 20 out of 48 CD patients (41.7%), among them 9 were treated surgically. All patients included were resistant to anti-TNF-α treatment. Fifty-one percent had presented side effects linked to anti-TNF-α, including psoriasis and anaphylactic reaction. The average Pediatric Crohn Disease Activity Index (PCDAI) at induction was 28.7 (5-85), 18.7 (0-75) at 3 months of treatment and 10 (0-35) at the last follow-up. The average Pediatric Ulcerative Colitis Activity Index at induction was 47 (25-65), 25 (15-40) at 3 months of treatment and 18.3 (0-35) at the last follow-up. No severe side effects were observed. CONCLUSION: In this retrospective, multicentral study, ustekinumab proved to be efficient in pediatric patients resistant to anti-TNF-α. PCDAI has been significantly improved in patients with severe disease, treated with ustekinumab.

IgA vasculitis in patients with inflammatory bowel disease: new insights into the role of TNF-α blockers.

OBJECTIVE: The association of IgA vasculitis (IgAV) and IBD is rarely described, mainly during anti-TNF-α therapy. We aimed to describe the association of IgAV and IBD. METHODS: We retrospectively analysed the association of IgAV and IBD through the implication of the GETAID and FVSG networks. Characteristics of IBD and IgAV were collected using a standardized case report form. RESULTS: Forty-three cases were included. IBD [mainly Crohn's disease (CD) in 58%] preceded IgAV in 38 (88%), with median interval of 9.2 (IQR 5.4-15.4) years. In these 38 patients, at IgAV diagnosis, five (13%) had active IBD and 28 (74%) were treated with anti-TNF-α for a median duration of 31.5 (IQR 19-56) months. Main IgAV manifestations were purpura all patients (100%), joints in 20/35 (57%), renal in 15/35 (43%) and gastrointestinal in 11/35 (31%) involvement. IgAV was treated with glucocorticoids in 25 (66%), colchicine in six (16%), CYC in six (16%) and anti-TNF-α were discontinued in 15/28 (54%). No IgAV relapse occurred when TNF-α blockers were stopped, vs 23% in patients pursuing it. Conversely, five (33%) had IBD flare or complication after anti-TNF-α cessation vs one (8%) in those continuing biologics. Anti-TNF-α were resumed in six (40%), with subsequent IgAV relapse in four (67%). CONCLUSIONS: This large cohort suggests that TNF-α blockers may promote the onset of IgAV in IBD. Discontinuation of anti-TNF-α was associated with vasculitis remission but increased risk of IBD relapses, whereas continuation of anti-TNF-α was associated with IBD remission but vasculitis relapse.

Increased Use of Anti-Tumor Necrosis Factor Following the Implementation of the ECCO-ESPGHAN Guidelines and its Impact on the Outcome of Pediatric Crohn's Disease: A Retrospective Single-Center Study.

OBJECTIVES: The first ECCO-ESPGHAN guidelines for the medical management of pediatric Crohn disease (CD) were published in 2014. Whether their implementation, and the consequent increased use of an upfront anti-tumor necrosis factor therapy, have changed the course of the disease has not been investigated yet. We aimed at comparing the evolution of pediatric CD patients diagnosed and treated before and after 2014. METHODS: Single-center retrospective study including all children diagnosed with CD from January 2010 to December 2018. Patients diagnosed between 2010 and 2014 (group 1) were compared to those diagnosed after 2014 (group 2). For each patient, at baseline and every 6-month, number of relapses, the occurrence of complication, therapy received and biological parameters were noted, as well as any endoscopic or radiologic evaluation. RESULTS: One hundred and fifty-four patients were included in the analysis, 78 (51%) diagnosed after 2014. The cumulative probability of a relapse-free and surgery-free course was significantly higher for patients treated according to the guidelines (log rank hazard ratio [HR] = 1,818, P = 0.003 and HR = 3,15, 95% confidence interval, P = 0.04, respectively). Mucosal healing rate was significantly higher among patients of group 2 at 1 and 2 years (P = 0.04 and P = 0.05, respectively), while no significant difference was observed for transmural healing rates, as well as for the risk of complications. CONCLUSIONS: The implementation of the 2014 CD guidelines appears to have a significant impact on disease outcomes, with a significantly lower risk for relapse and surgery, while no effect could be observed on the risk of developing complications.

Benign Evolution of SARS-Cov2 Infections in Children With Inflammatory Bowel Disease: Results From Two International Databases.

The coronavirus disease 2019 (COVID-19) pandemic caused by the highly infectious severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) presents most often with mild clinical symptoms, but the severe forms are of major concern.1 SARS-CoV-2 enters human cells via the angiotensin-converting enzyme 2 receptor, expressed on epithelial and endothelial cells.2 Because the highest angiotensin-converting enzyme 2 expression is in the terminal ileum and colon, and up-regulated further during inflammation, and many COVID-19 patients experience gastrointestinal symptoms, longitudinal data are necessary to determine whether inflammatory bowel disease (IBD) patients are at risk for severe or complicated COVID-19. A recent analysis in IBD patients from the Surveillance Epidemiology of Coronavirus Under Research Exclusion for Inflammatory Bowel Disease (SECURE-IBD) registry showed older age, steroid medication, and comorbidities as risk factors for severe evolution, and the same study showed that the 29 IBD patients younger than age 20 had only mild disease courses.3 This report describes the disease course of COVID-19 in an expanded sample of pediatric IBD patients from 2 international databases.

Prior infection by seasonal coronaviruses, as assessed by serology, does not prevent SARS-CoV-2 infection and disease in children, France, April to June 2020.

BackgroundChildren have a low rate of COVID-19 and secondary severe multisystem inflammatory syndrome (MIS) but present a high prevalence of symptomatic seasonal coronavirus infections.AimWe tested if prior infections by seasonal coronaviruses (HCoV) NL63, HKU1, 229E or OC43 as assessed by serology, provide cross-protective immunity against SARS-CoV-2 infection.MethodsWe set a cross-sectional observational multicentric study in pauci- or asymptomatic children hospitalised in Paris during the first wave for reasons other than COVID (hospitalised children (HOS), n = 739) plus children presenting with MIS (n = 36). SARS-CoV-2 antibodies directed against the nucleoprotein (N) and S1 and S2 domains of the spike (S) proteins were monitored by an in-house luciferase immunoprecipitation system assay. We randomly selected 69 SARS-CoV-2-seropositive patients (including 15 with MIS) and 115 matched SARS-CoV-2-seronegative patients (controls (CTL)). We measured antibodies against SARS-CoV-2 and HCoV as evidence for prior corresponding infections and assessed if SARS-CoV-2 prevalence of infection and levels of antibody responses were shaped by prior seasonal coronavirus infections.ResultsPrevalence of HCoV infections were similar in HOS, MIS and CTL groups. Antibody levels against HCoV were not significantly different in the three groups and were not related to the level of SARS-CoV-2 antibodies in the HOS and MIS groups. SARS-CoV-2 antibody profiles were different between HOS and MIS children.ConclusionPrior infection by seasonal coronaviruses, as assessed by serology, does not interfere with SARS-CoV-2 infection and related MIS in children.

Is sexual harassment and psychological abuse among medical students a fatality? A 2-year study in the Paris Descartes School of Medicine.

INTRODUCTION: An observatory of sexual harassment and psychological abuse was set up at one of France's largest schools of medicine to both quantify and reduce sexual harassment or psychological abuse of medical students. METHODS: Over a 2-year period, we described the evolution of sexual harassment and psychological abuse and explored for associated factors. Moreover, a qualitative analysis using an inductive approach was performed from students' verbatim. RESULTS: 2795 responses were collected. Sexual harassment was reported in 7% and psychological abuse in 15%, at baseline, and decreased after the observatory was set up. Women had higher odds of being a victim of sexual harassment. Older students reported less often psychological abuse and being a witness of sexual harassment. Surgery departments were associated with up to 5.7-fold increased odds of sexual harassment. Surgery and pediatrics departments were associated with a 2-fold increased odds of psychological abuse. Qualitative analysis revealed four categories: humiliation, the feeling of inferiority, sexual harassment, and manifestations of violence. CONCLUSION: During clerkships, factors associated with higher odds of sexual harassment and psychological abuse were female gender, younger age, and departments of surgery. Setting up such an observatory may contribute to reduce this burden and provide a useful tool to raise awareness.

Neurological Adverse Effects Associated With Anti-tumor Necrosis Factor Alpha Antibodies in Pediatric Inflammatory Bowel Diseases.

OBJECTIVES: Neurological adverse effects (NAEs) induced by biotherapies have been reported in the literature mainly in adult patients with inflammatory bowel disease (IBD), rheumatic diseases, or psoriasis. There are scant data in children. Aims of this study are to report and describe noninfective NAE associated with anti-TNFα antibodies in pediatric IBD, and to evaluate their incidence. METHODS: We retrospectively collected all reports of NAE in pediatric IBD treated with anti-TNFα antibodies recorded in the French Pharmacovigilance Database. To estimate the national incidence of NAEs, we extrapolated data from the French regional inception population-based cohort EPIMAD. RESULTS: Between 2000 and 2018, 231 adverse events in pediatric IBD exposed to anti-TNFα antibodies were reported to this Database. Seventeen NAEs (7.36%) were collected: 8 severe NAE (1 demyelinating neuropathy, 1 optic neuritis, 1 acute transverse myelitis, 1 polyradiculoneuritis, 1 sensorineural hearing loss, 1 seizure, 1 stroke, and 1 glioma), 7 moderate NAE (headaches), and 2 neuropsychic events. The median delay between anti-TNFα start and NAE occurrence was 6 months (range: 13 days to 26 months). In 10 of 17 patients, anti-TNFα antibodies were stopped. Nine of 17 patients had a complete resolution (including 2 severe NAE) and 8 of 17 a partial resolution (including 6 severe NAE). We estimate the incidence of severe NAE in pediatric IBD treated with anti-TNFα antibodies at 1 case for 10,000 patients-year in France. CONCLUSIONS: NAE associated with anti-TNFα antibodies in pediatric IBD are rare. In severe NAE, we recommend to discontinue anti-TNFα therapy and to consider alternative treatment.

Eating disorder or oesophageal achalasia during adolescence: diagnostic difficulties.

Marine was a fourteen and a half-year-old adolescent female hospitalized for an eating disorder (ED) of the anorexic type with purging behaviors. She has had a complicated life course, made up of disruptions and discontinuities, both family and school. Since the age of five, Marine had been intermittently treated in psychiatry for a diagnosis of oppositional defiant disorder. The current illness started with spontaneous and induced vomiting associated with major weight loss (body mass index, 15.27 kg m-2). The diagnosis of anorexia nervosa was established after several opinions from professionals in five Parisian university pediatric departments, where additional investigations were carried out without any somatic cause being identified. In this context, Marine was transferred to a child psychiatry unit. There, she had acute dyspnea during the insertion of a nasogastric tube. As a result, a new specialized opinion was sought from a pediatric gastroenterologist and further explorations were performed (oeso-gastroduodenal transit and manometry), leading to the conclusion to an oesophageal achalasia requiring surgical treatment. This case report highlights that the exclusion of any organic disorder should be a priority in the diagnostic assessment of an ED. Oesophageal achalasia is a rare differential diagnosis and should be considered in case of swallowing difficulties or dysphagia. Health care professionals should take care to provide appropriate somatic follow-up for patients with psychiatric disorders.

Hemodynamic Shock Caused by Tension Pneumoperitoneum in a 5-Year-Old Girl.

Tension pneumoperitoneum is a relatively rare occurrence in the pediatric population. However, tension pneumoperitoneum is associated with significant morbidity and mortality if it is not promptly diagnosed and treated. A 5-year-old girl was admitted to emergency department with abdominal pain. She was in shock, and the radiograph film of the abdomen revealed a voluminous tension pneumoperitoneum. Aggressive fluid challenges were performed in intensive care followed by urgent laparotomy. Primary abdominal compartment due to trapped gas caused a decreased venous return and visceral perfusion. In the absence of hemodynamic improvement after vascular filling, needle decompression was performed before surgery.

Weaning Off Prognosis Factors of Home Parenteral Nutrition for Children With Primary Digestive Disease.

OBJECTIVES: The aim of the present study was to describe the indications for home parenteral nutrition (HPN) in children with primary digestive diseases and to identify factors associated with weaning off. METHODS: All the children initially discharged on HPN between January 1, 2000, and December 31, 2009, for chronic intestinal failure (IF) were included. The associations between clinical factors and weaning off of HPN were assessed using a multivariable Cox regression model. RESULTS: Among the 151 children (boys = 58%) included in this study, 98 (65%) presented with short bowel syndrome (SBS), 17 (11%) with digestive neuromuscular disorders, 14 (9%) with mucosal diseases, 13 (9%) with inflammatory bowel disease, and 9 (6%) with other primary digestive diseases. The probability of survival was ∼100%. At the end of the follow-up, the probability for weaning off of HPN was 0.73 (95% confidence interval 0.54-0.84) but varied according to the underlying cause of IF (for example, SBS and inflammatory bowel disease had a better prognosis). The median time until weaning off was 21 months (95% confidence interval 18-38 months). Unfavourable prognostic factors for weaning off of HPN included a bowel remnant of <40 cm, the presence of <50% of the colon, and daily lipid intakes >1.5 g · kg · day. Underlying disease was also associated with weaning off. CONCLUSIONS: HPN is a safe therapeutic option for children with chronic IF requiring long-term nutritional management. Prognostic factors for weaning off of HPN were identified, and they highlight the relevance of SBS anatomy and parenteral nutrition caloric intake. The outcome of children on HPN was primarily dependent on the underlying disease.

Long-term treatment with teduglutide: a 48-week open-label single-center clinical trial in children with short bowel syndrome.

BACKGROUND: Short bowel syndrome (SBS) is the main cause of intestinal failure in children. OBJECTIVES: This single-center study evaluated the safety and efficacy of teduglutide in pediatric patients with SBS-associated intestinal failure (SBS-IF). METHODS: Children with SBS followed at our center with ≥2 y on parenteral nutrition (PN) and with small bowel length <80 cm who had reached a plateau were consecutively included in the study. At baseline, participants underwent a clinical assessment including a 3-d stool balance analysis, which was repeated at the end of the study. Teduglutide was administered subcutaneously 0.05 mg/kg/d for 48 wk. PN dependence was expressed as the PN dependency index (PNDI), which is the ratio PN non-protein energy intake/REE. Safety endpoints included treatment-emergent adverse events and growth parameters. RESULTS: Median age at inclusion was 9.4 y (range: 5-16). The median residual SB length was 26 cm (IQR: 12-40). At baseline, the median PNDI was 94% (IQR: 74-119), (median PN intake: 38.9 calories/kg/d, IQR: 26.1-48.6). At week 24, 24 (96%) children experienced a reduction of >20% of PN requirements with a median PNDI = 50% (IQR: 38-81), (PN intake: 23.5 calories/kg/d IQR: 14.6-26.2), P < 0.01. At week 48, 8 children (32%) were weaned completely off PN. Plasma citrulline increased from 14 µmol/L (IQR: 8-21) at baseline to 29 µmol/L (IQR: 17-54) at week 48 (P < 0.001). Weight, height, and BMI z-scores remained stable. The median total energy absorption rate increased from 59% (IQR: 46-76) at baseline to 73% (IQR: 58-81) at week 48 (P = 0.0222). Fasting and postprandial endogenous GLP-2 concentrations increased at weeks 24 and 48 compared with baseline. Mild abdominal pain at the early phase of treatment, stoma changes, and redness at the injection site were commonly reported. CONCLUSIONS: Increased intestinal absorption and PN dependency reduction were observed with teduglutide treatment in children with SBS-IF. TRIAL REGISTRATION: ClinicalTrials.gov NCT03562130. https://clinicaltrials.gov/ct2/show/NCT03562130?term=NCT03562130&draw=2&rank=1.

A critical review of adalimumab for the treatment of moderate-to-severe active ulcerative colitis in children.

INTRODUCTION: Anti-tumor necrosis factor (TNF) antibodies play a major role in treating inflammatory bowel disease (IBD), both in adult and pediatric patients. While there is a large number of studies on efficacy and safety of infliximab in treating children and adolescents with ulcerative colitis (UC), data on adalimumab (ADA) are scarce. AREAS COVERED: Here, we review published case reports, cohort and real-time data, as well as the first randomized trial, ENVISION I, using ADA for treating pediatric UC. Available evidence confirms good efficacy in inducing and maintaining remission in children and adolescents with UC, with even higher response rates compared to adult UC. ENVISION I showed that in UC patients responding to ADA induction therapy, almost half of the patients remained in remission after 52 weeks of therapy on high-dosing ADA (weekly administration). As already well experienced with other biologics, dosing schemes are different between pediatric and adult patients, with children often requiring higher dosing. EXPERT OPINION: Further data are required to better understand how to optimize ADA therapy. The present and still-growing evidence places subcutaneous (sc.) anti-TNF-medication as alternative first-line therapy also for pediatric UC. This is also reflected by the preference for sc. medication of adolescent patients allowing less frequent and autonomous drug administration.

Congenital enteropathies involving defects in enterocyte structure or differentiation.

Congenital enteropathies (CE) are a group of rare inherited diseases with a typical onset early in life. They involve defects in enterocyte structure or differentiation. They can cause a severe condition of intestinal failure (IF). The diagnostic approach is based first on clinical presentation (consanguinity, prenatal expression, polyhydramnios, early neonatal onset, aspect of stools, persistence at bowel rest, associated extra-digestive manifestations….) and histo-pathological analyses. These rare intestinal diseases cause protracted diarrhea that might resolve, for a few, with a dietetic approach. However, protracted or permanent IF may require long term parenteral nutrition and, in limited cases, intestinal transplantation. With the progresses in both clinical nutrition and genetics, many of these CE are nowadays associated with recognized gene mutations. It improved our knowledge and the understanding in the patho-physiology of these diseases, thus, leading potentially to therapeutic perspectives. These review cover most of the early onset CE and excludes the immune related diarrhea.

Mitchell-Riley Syndrome: Improving Clinical Outcomes and Searching for Functional Impact of RFX-6 Mutations.

Aims/Hypothesis: Caused by biallelic mutations of the gene encoding the transcription factor RFX6, the rare Mitchell-Riley syndrome (MRS) comprises neonatal diabetes, pancreatic hypoplasia, gallbladder agenesis or hypoplasia, duodenal atresia, and severe chronic diarrhea. So far, sixteen cases have been reported, all with a poor prognosis. This study discusses the multidisciplinary intensive clinical management of 4 new cases of MRS that survived over the first 2 years of life. Moreover, it demonstrates how the mutations impair the RFX6 function. Methods: Clinical records were analyzed and described in detail. The functional impact of two RFX6R181W and RFX6V506G variants was assessed by measuring their ability to transactivate insulin transcription and genes that encode the L-type calcium channels required for normal pancreatic beta-cell function. Results: All four patients were small for gestational age (SGA) and prenatally diagnosed with duodenal atresia. They presented with neonatal diabetes early in life and were treated with intravenous insulin therapy before switching to subcutaneous insulin pump therapy. All patients faced recurrent hypoglycemic episodes, exacerbated when parenteral nutrition (PN) was disconnected. A sensor-augmented insulin pump therapy with a predictive low-glucose suspension system was installed with good results. One patient had a homozygous c.1517T>G (p.Val506Gly) mutation, two patients had a homozygous p.Arg181Trp mutation, and one patient presented with new compound heterozygosity. The RFX6V506G and RFX6R181W mutations failed to transactivate the expression of insulin and genes that encode L-type calcium channel subunits required for normal pancreatic beta-cell function. Conclusions/Interpretation: Multidisciplinary and intensive disease management improved the clinical outcomes in four patients with MRS, including adjustment of parenteral/oral nutrition progression and advanced diabetes technologies. A better understanding of RFX6 function, in both intestine and pancreas cells, may break ground in new therapies, particularly regarding the use of drugs that modulate the enteroendocrine system.

Defective IL10 signaling defining a subgroup of patients with inflammatory bowel disease.

OBJECTIVES: Early onset inflammatory bowel diseases (EO-IBD) developing during the first year of life are likely to reflect inherited defects in key mechanism(s) controlling intestinal homeostasis, as recently suggested for interleukin 10 (IL10). Thus, we aimed to further elaborate the hypothesis of defective anti-inflammatory responses in patients with IBD. METHODS: The capacities of transforming growth factor ß (TGFß) and IL10 to inhibit proinflammatory cytokine production by monocyte-derived dendritic cells (MoDC) or peripheral blood cells (PBMC) was analyzed in 75 children with IBD, including 13 infants with EO-IBD (in whom autoimmune diseases or classical immunodeficiencies were ruled out). IL10 receptor-A/-B expression, STAT3 activation in response to IL6, IL10, IL21, IL22 were analyzed by FACS and western blotting. IL10RA and B genes were sequenced. The response to IL22 was tested in ileal/colonic tissue cultures. Tissue gene expression was analyzed by Taqman real-time polymerase chain reaction. RESULTS: Production of IL10 in response to bacterial motifs was normal in all IBD patients. In contrast to our original hypothesis, no defect of the anti-inflammatory potential of TGFß and IL10 was observed in children with IBD or EO-IBD except two infants who presented with granuloma-positive colitis at 3 months of life: no response to IL10 was observed secondary to mutations in the α (p.R262C) or ß (p.E141X) chain of IL10R, respectively, although a fully functional Jak-STAT3 pathway was present in both patients. When analyzing the regulation of intestinal bacterial clearance, we detected a defect in the patient with absent IL10 RB to upregulate protective transcripts in response to IL22, whereas all other EO-IBD patients, including the patient with an abnormal α chain, responded normally. CONCLUSIONS: Impaired IL10 signaling characterizes a subgroup of IBD patients, whereas the majority of children with severe IBD including EO forms normally produces and responds to IL10. Defective IL22 signaling may additionally impair intestinal epithelial clearance. Our data point out the complexity of IBD, which represent a group of distinct diseases with several pathogenetic abnormalities.

Faecalibacterium prausnitzii is an anti-inflammatory commensal bacterium identified by gut microbiota analysis of Crohn disease patients.

A decrease in the abundance and biodiversity of intestinal bacteria within the dominant phylum Firmicutes has been observed repeatedly in Crohn disease (CD) patients. In this study, we determined the composition of the mucosa-associated microbiota of CD patients at the time of surgical resection and 6 months later using FISH analysis. We found that a reduction of a major member of Firmicutes, Faecalibacterium prausnitzii, is associated with a higher risk of postoperative recurrence of ileal CD. A lower proportion of F. prausnitzii on resected ileal Crohn mucosa also was associated with endoscopic recurrence at 6 months. To evaluate the immunomodulatory properties of F. prausnitzii we analyzed the anti-inflammatory effects of F. prausnitzii in both in vitro (cellular models) and in vivo [2,4,6-trinitrobenzenesulphonic acid (TNBS)-induced] colitis in mice. In Caco-2 cells transfected with a reporter gene for NF-kappaB activity, F. prausnitzii had no effect on IL-1beta-induced NF-kappaB activity, whereas the supernatant abolished it. In vitro peripheral blood mononuclear cell stimulation by F. prausnitzii led to significantly lower IL-12 and IFN-gamma production levels and higher secretion of IL-10. Oral administration of either live F. prausnitzii or its supernatant markedly reduced the severity of TNBS colitis and tended to correct the dysbiosis associated with TNBS colitis, as demonstrated by real-time quantitative PCR (qPCR) analysis. F. prausnitzii exhibits anti-inflammatory effects on cellular and TNBS colitis models, partly due to secreted metabolites able to block NF-kappaB activation and IL-8 production. These results suggest that counterbalancing dysbiosis using F. prausnitzii as a probiotic is a promising strategy in CD treatment.