Rare and severe adverse events in children with inflammatory bowel disease: analysis of data from the PIBD-SETQuality Safety Registry.

BACKGROUND: Rare and severe adverse events can occur in children with inflammatory bowel disease (IBD), and the relationship with disease or drug treatment is often uncertain. We aimed to establish a method of reporting adverse events of interest in children with IBD, allowing for estimates of incidence rates with comparison between different regions, and, if possible, to compare with published data on rates of adverse events in children overall. METHODS: For this analysis, we used data from the Paediatric Inflammatory Bowel Disease Network for Safety, Efficacy and Treatment and Quality improvement of care (PIBD-SETQuality) Safety Registry, which collects data on multiple rare and severe adverse events in children younger than 19 years with IBD. Overall, the registry collected data on ten prespecified rare and severe adverse events in children with IBD, as established by a panel of paediatric IBD experts, via reports from paediatric gastroenterologists at participating hospitals between Nov 1, 2016, and March 31, 2023. Reporting physicians, who could only be paediatric gastroenterologists or IBD nurses reporting on behalf of paediatric gastroenterologists, were recruited through invitations sent to both national and international IBD networks and at conferences. Once per month, participating paediatric gastroenterologists received an email with an anonymous and unique link to an online survey asking them to report whether any of ten rare and severe adverse events had occurred in a patient in their paediatric-IBD population in the previous month. Prevalent or retrospective rare and severe adverse events were excluded, as were events occurring in children with an unconfirmed diagnosis of IBD or for whom inflammatory colitis was part of a monogenic immunodeficiency disorder. Duplicates and events that did not meet the definitions and criteria were excluded. Physicians could also report other, non-categorised adverse events if they considered them rare and severe. In case of no response, up to two reminders were sent for each per-month survey. Annual denominator data surveys were sent to obtain the total number of person-years for the estimation of incidence rates, which were calculated via Poisson regression models. FINDINGS: Responses were gathered from 220 paediatric gastroenterologists from 167 centres. 121 centres were in Europe, 23 centres were in North America, 17 centres were in Asia, and six centres were in Oceania. Combined, the total population with paediatric IBD consisted of an estimated 30 193 children with 114 528 person-years of follow-up. 451 adverse events were initially reported. After excluding and reorganising adverse events, 402 were eligible; 261 (65%) were categorised and 141 (35%) were non-categorised. The most frequently reported adverse events were venous-thromboembolic events (n=66), renal failure (n=43), opportunistic infections (n=42), and cancer (n=33). Haemophagocytic lymphohistiocytosis (n=4) and liver failure (n=3) were the least frequently reported adverse events. Incidence rates per 10 000 person-years were 5·50 (95% CI 4·25-6·97) for venous-thromboembolic events, 3·75 (2·74-4·99) for renal failure, 3·67 (2·67-4·89) for opportunistic infection, and 2·88 (2·01-3·98) for cancer. Of 66 venous-thromboembolic events, 31 (47%) involved cerebral venous sinus thrombosis at an incidence rate of 2·71 (95% CI 1·86-3·77). INTERPRETATION: The PIBD-SETQuality Safety Registry enabled us to identify incidence rates of rare and severe adverse events in children with IBD. Our findings can guide physicians and enhance awareness of the incidence of adverse events in children with IBD that are considered to be rare. FUNDING: EU Horizon 2020 Research and Innovation Programme.

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.

Improved clinical outcomes with early anti-tumour necrosis factor alpha therapy in children with newly diagnosed Crohn's disease: real world data from the international prospective PIBD-SETQuality inception cohort study.

BACKGROUND & AIMS: Treatment guidelines for paediatric Crohn's disease (CD) suggest early use of anti-tumour necrosis factor alpha (anti-TNF) in high-risk individuals. The aim is to evaluate the effect of early anti-TNF in a real-world cohort. METHODS: Children with newly-diagnosed CD were prospectively recruited at 28 participating sites of the international observational PIBD-SETQuality study. Outcomes were compared at 3 months, 1 and 2 years between patients receiving early anti-TNF (<90 days after diagnosis) and those not receiving early anti-TNF. Outcomes included sustained steroid-free remission (SSFR) without treatment intensification (specified as SSFR*) and sustained steroid-free mild/inactive disease without treatment intensification (specified as SSFMI*). Penalised logistic regression model-based standardisation was applied to estimate the relative risks (RR) of early therapy on outcomes. RRs were estimated for high-risk and low-risk patients based on presence of predictors of poor outcome (POPOs) and disease activity at diagnosis. RESULTS: In total, 331 children (median age 13.9 years [IQR 12.2 - 15.3]) were enrolled, with 135 (41%) receiving early anti-TNF. At 1 year, patients on early anti-TNF had higher rates of SSFR* (30% vs. 14%, p<0.001) and SSFMI* (69% vs. 33%, p<0.001), with RRs of 2.95 (95%CI 1.63-5.36) and 4.67 (95%CI 2.46-8.87) respectively. At 1 year, the RRs for SSFMI* were higher, and statistically significant in high-risk patients, i.e. those with moderate/severe disease compared to mild/inactive disease at diagnosis (5.50 [95%CI 2.51-12.05]) vs. 2.91 [95%CI 0.92-9.11]), and those with any POPO compared to no POPO (5.05 [95%CI 2.45-10.43] vs. 3.41 [95%CI 0.54-21.7]). CONCLUSION: In this cohort of children with newly-diagnosed CD, early anti-TNF demonstrated superior effectiveness in high-risk patients.

Validation of predictive models for disease outcomes in paediatric ulcerative colitis: A multicentre prospective inception cohort.

BACKGROUND: Several studies have proposed models to predict disease outcomes in paediatric ulcerative colitis (UC), notably PROTECT, Schechter and PIBD-ahead, but none has been validated by external cohorts AIM: To explore these models in a prospective multicentre inception cohort METHODS: Children newly diagnosed with UC in 17 centres were followed at disease onset and 3 and 12 months thereafter, as well as at last visit. Outcomes included steroid-free remission (SFR) and acute severe colitis (ASC). RESULTS: Of the 223 included children, 74 (34%), 97 (43%) and 52 (23%) presented with mild, moderate and severe disease, respectively. SFR rate was 35% at 3 months and 47% at 12 months (62% of those with mild disease at diagnosis vs. 41% in moderate-severe disease; p = 0.01). Thirty-six (16%) children developed ASC during the first month after diagnosis, and 53 (24%) during the first year. The AUC of the PROTECT model for predicting SFR at 3 and 12 months was 0.78 [95% CI 0.65-0.92] and 0.57 [95% CI 0.47-0.66], respectively. The sensitivity/specificity/PPV/NPV of Schechter's criteria to predict sustained SFR at 12 months was 50%/60%/35%/74%. ASC was predicted only by the PUCAI score at diagnosis and at 3 months. CONCLUSIONS: The PROTECT model had a good predictive utility for SFR at 3 months, but not at 12 months. The other predictive models did not achieve sufficient accuracy, which was far from that reported in the original studies. This highlights the necessity for external validation of any prediction model prior to its implementation into clinical practice.

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.

Paediatric Inflammatory Bowel Disease: A Multi-Stakeholder Perspective to Improve Development of Drugs for Children and Adolescents.

BACKGROUND AND AIMS: Despite recent approvals for new drugs to treat adults with Crohn's disease or ulcerative colitis, there are only two approved advanced treatment options [infliximab and adalimumab] for children with inflammatory bowel disease [IBD]. There are many potential new therapies being developed for adult and paediatric IBD. Moreover, regulatory agencies in both the European Union and USA have processes in place to support the early planning and initiation of paediatric studies. Nevertheless, unacceptable delays in approvals for use of drugs in children persist, with an average 7-year gap, or longer, between authorization of new IBD drugs for adults and children. METHODS: A 2-day virtual meeting was held during April 14-15, 2021 for multi-stakeholders [clinical academics, patient community, pharmaceutical companies and regulators] to discuss their perspectives on paediatric drug development for IBD. RESULTS: The multi-stakeholder group presented, discussed and proposed actions to achieve expediting the approval of new drugs in development for paediatric IBD. CONCLUSIONS: Collaborative action points for all stakeholders are required to make progress and facilitate new drug development for children with IBD.

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.

UNC45A deficiency causes microvillus inclusion disease-like phenotype by impairing myosin VB-dependent apical trafficking.

Variants in the UNC45A cochaperone have been recently associated with a syndrome combining diarrhea, cholestasis, deafness, and bone fragility. Yet the mechanism underlying intestinal failure in UNC45A deficiency remains unclear. Here, biallelic variants in UNC45A were identified by next-generation sequencing in 6 patients with congenital diarrhea. Corroborating in silico prediction, variants either abolished UNC45A expression or altered protein conformation. Myosin VB was identified by mass spectrometry as client of the UNC45A chaperone and was found misfolded in UNC45AKO Caco-2 cells. In keeping with impaired myosin VB function, UNC45AKO Caco-2 cells showed abnormal epithelial morphogenesis that was restored by full-length UNC45A, but not by mutant alleles. Patients and UNC45AKO 3D organoids displayed altered luminal development and microvillus inclusions, while 2D cultures revealed Rab11 and apical transporter mislocalization as well as sparse and disorganized microvilli. All those features resembled the subcellular abnormalities observed in duodenal biopsies from patients with microvillus inclusion disease. Finally, microvillus inclusions and shortened microvilli were evidenced in enterocytes from unc45a-deficient zebrafish. Taken together, our results provide evidence that UNC45A plays an essential role in epithelial morphogenesis through its cochaperone function of myosin VB and that UNC45A loss causes a variant of microvillus inclusion disease.

High Impact of Pediatric Inflammatory Bowel Disease on Caregivers' Work Productivity and Daily Activities: An International Prospective Study.

OBJECTIVES: To evaluate the longitudinal evolution of work productivity loss and activity impairment in caregivers of children with inflammatory bowel disease (IBD). We also evaluated the associations between these impairments, IBD-related factors, and caregivers' health-related quality of life (HRQOL) and estimated the indirect costs related to work absenteeism. STUDY DESIGN: Since January 2017, children with newly diagnosed IBD were enrolled prospectively in the Pediatric Inflammatory Bowel Disease Network for Safety, Efficacy, Treatment and Quality improvement of care study. The impact of pediatric-onset IBD on caregivers' socioeconomic functioning (work and daily activities) and HRQOL was assessed using the Work Productivity and Activity Impairment for caregivers questionnaire and the European Quality of Life Five Dimension Five Level questionnaire, at diagnosis and 3 and 12 months of age. Generalized estimating equation models were applied to evaluate outcomes longitudinally, adjusted for IBD type, disease activity, and child's age at diagnosis. RESULTS: Up to July 2021, 491 children with IBD were eligible for analysis of caregivers' Work Productivity and Activity Impairment questionnaire. At diagnosis, the mean caregivers' employment rate was 78.4%; the adjusted mean work productivity loss was 44.6% (95% CI, 40.2%-49.0%), and the adjusted mean activity impairment was 34.3% (95% CI, 30.8%-37.7%). Work productivity loss and activity impairment significantly decreased over time and were associated with disease activity, but not with IBD type or child's age. Caregivers' HRQOL was associated with both impairments. Costs related to work absenteeism were at least €6272 ($7276) per patient during the first year after diagnosis. CONCLUSIONS: Caregivers of children with IBD experience significant impairments in work and daily activities, especially at diagnosis. The impact decreases thereafter and is associated with disease activity and caregivers' HRQOL. Work absenteeism results in high indirect costs.

Pediatric Prescriptions of Proton Pump Inhibitors in France (2009-2019): A Time-Series Analysis of Trends and Practice Guidelines Impact.

OBJECTIVE: To describe the ambulatory proton pump inhibitor (PPI) prescription in French children, its trends, and the impact of French (2014) and international (2018) clinical guidelines. STUDY DESIGN: We described PPI prescription rates based on national dispensation data in French children (IQVIA's Xponent database, 2009-2019). Using a segmented linear regression, we assessed the impact of clinical guidelines on PPI prescription rates. Analyses were performed for the overall pediatric population and by age subgroups (infants <2 years old, children 2-11 years old, adolescents 12-17 years old). RESULTS: During the study period, 8 060 288 pediatric PPI prescriptions were filled, with a mean PPI prescription rate of 52.5 per 1000 inhabitants per year. Between 2009 and 2019, the PPI prescription rate increased by 41% in the overall pediatric population (+110% in infants). The PPI prescription rate showed seasonal patterns with peaks in winter. After the release of French guidelines, significant decreases in trends of prescription rates occurred overall (change in trend -0.28, 95% CI -0.34;-0.23) and across all age groups. In infants, this change in trend was not sufficient to reverse the PPI prescription rate that was still increasing over time. In children, the PPI prescription rate slightly decreased and in adolescents, it was stable. After the release of international guidelines, a significant decrease in trend occurred in adolescents only (change in trend -0.26, 95% CI -0.47; -0.04). CONCLUSIONS: The pediatric PPI prescription rate in France was high, displayed a major increase over the last decade, mainly among infants, and was modestly affected by clinical guidelines.

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.

The Incidence and Characteristics of Venous Thromboembolisms in Paediatric-Onset Inflammatory Bowel Disease: A Prospective International Cohort Study Based on the PIBD-SETQuality Safety Registry.

BACKGROUND AND AIMS: Guidelines regarding thromboprophylaxis for venous thromboembolisms [VTEs] in children with inflammatory bowel disease [IBD] are based on limited paediatric evidence. We aimed to prospectively assess the incidence of VTEs in paediatric-onset IBD [PIBD], characterize PIBD patients with a VTE and identify potential IBD-related risk factors. METHODS: From October 2016 to September 2020, paediatric gastroenterologists prospectively replied to the international Safety Registry, monthly indicating whether they had observed a VTE case in a patient <19 years with IBD. IBD details [type, Paris classification, clinical and biochemical disease activity, treatment] and VTE details [type, location, treatment, outcome] were collected. To estimate VTE incidence, participants annually reported the number of PIBD patients, data source and catchment area of their centre. A systematic literature review and meta-analysis was performed to calculate the VTE incidence in the general paediatric population. RESULTS: Participation of 129 PIBD centres resulted in coverage of 24 802 PIBD patients. Twenty cases of VTE were identified [30% Crohn's disease]. The incidence of VTEs was 3.72 (95% confidence interval [CI] 2.27-5.74) per 10 000 person-years, 14-fold higher than in the general paediatric population (0.27 [95% CI 0.18-0.38], p < 0.001). Cerebral sinus venous thrombosis was most frequently reported [50%]. All but one patient had active IBD, 45% were using steroids and 45% were hospitalized. No patient received thromboprophylaxis, whereas according to current PIBD guidelines, this was recommended in 4/20 patients. CONCLUSION: There is an increased risk of VTEs in the PIBD population compared to the general paediatric population. Awareness of VTE occurrence and prevention should be extended to all PIBD patients with active disease, especially those hospitalized.

Efficacy and safety of adalimumab in paediatric patients with moderate-to-severe ulcerative colitis (ENVISION I): a randomised, controlled, phase 3 study.

BACKGROUND: Biologic treatment options are limited for children with ulcerative colitis. The aim of this study was to assess the safety and efficacy of adalimumab in children with moderate-to-severe ulcerative colitis. METHODS: The double-blind ENVISION I study was done at 24 hospitals in ten countries. Children (4-17 years) with moderate-to-severe ulcerative colitis despite stable doses of concurrent treatment with oral corticosteroids or immunosuppressants were enrolled. Per the original study design, patients were randomly assigned with an Interactive Voice Response System (IVRS) to receive either high-dose induction adalimumab (2·4 mg/kg [maximum 160 mg] at weeks 0 and 1) or standard-dose induction adalimumab (2·4 mg/kg at week 0 and placebo at week 1); both groups received 1·2 mg/kg (maximum 80 mg) at week 2 and 0·6 mg/kg (maximum 40 mg) at weeks 4 and 6. Patients with partial Mayo score (PMS) response at week 8 (defined as a decrease of two or more points and a decrease of ≥30% from baseline in PMS) were randomly assigned (2:2:1)-using IVRS-to receive either high-dose maintenance adalimumab (0·6 mg/kg weekly), standard-dose maintenance adalimumab (0·6 mg/kg every other week), or placebo up to week 52 (random assignment to the placebo group was ceased mid-trial, as was randomisation in the induction phase with all subsequent patients receiving open-label high-dose induction adalimumab). Coprimary endpoints were the proportion of patients with PMS remission at week 8 (intent-to-treat [ITT]-E population, not including those patients who were not randomised in the induction phase) and full Mayo score (FMS) remission at week 52 in week 8 PMS responders (maintenance ITT-E [mITT-E] population), for which the pooled adalimumab group (patients who received high-dose or standard-dose adalimumab) and the individual dose groups were compared against external adult placebo rates. We report results of the final confirmatory analysis. This trial is registered with ClinicalTrials.gov, NCT02065557. FINDINGS: 93 children were recruited between Oct 13, 2014, and Sept 5, 2018, to the main study (77 [83%] were randomly assigned [double-blind] to receive high-dose or standard-dose induction adalimumab; 16 [17%] received open-label high-dose induction adalimumab after study design change). At week 8, 74 (80%) children who were PMS responders continued to the maintenance period. 62 (84%) patients were randomly assigned to receive high-dose or standard-dose maintenance adalimumab treatment; 12 (16%) patients received placebo. In patients in the ITT-E population who were randomly assigned to receive high-dose induction adalimumab, a significantly higher proportion of patients were in PMS remission at week 8 (28 [60%] of 47) compared with external placebo (19·8%; p=0·0001). 13 (43%) of 30 patients in the standard-dose induction adalimumab group were in PMS remission at week 8 versus an external placebo rate of 19·8%, but this difference was not significant (p=0·38). Similarly, FMS remission at week 52 in children who were week 8 PMS responders was reported in a significantly higher proportion of patients in mITT-E population who received high-dose maintenance adalimumab (14 [45%] of 31 patients) versus external placebo at week 52 (18·4%; p=0·0001). Nine (29%) of 31 patients in the standard-dose maintenance adalimumab group were in FMS remission at week 52 versus an external placebo rate of 18·4%, but this difference was not significant (p=0·38). Remission rates in the pooled adalimumab groups were significantly better compared with external placebo (PMS remission at week 8: 41 [53%] of 77 patients; p<0·0001; FMS remission at week 52: 23 [37%] of 62 patients; p=0·0001). 21 (23%) of 93 patients in the main study had one or more treatment-emergent serious adverse events during any adalimumab exposure. The most common adverse events were headache, anaemia, and ulcerative colitis flare during the induction period and ulcerative colitis flare, headache, and nasopharyngitis during the maintenance period. INTERPRETATION: Clinically meaningful rates of remission and response were reported in children who received adalimumab in this study. No new safety signals were observed, suggesting that adalimumab is an efficacious and safe treatment option for children with moderate-to-severe ulcerative colitis. FUNDING: AbbVie.

Single-cell analysis of FOXP3 deficiencies in humans and mice unmasks intrinsic and extrinsic CD4+ T cell perturbations.

FOXP3 deficiency in mice and in patients with immune dysregulation polyendocrinopathy enteropathy X-linked (IPEX) syndrome results in fatal autoimmunity by altering regulatory T (Treg) cells. CD4+ T cells in patients with IPEX syndrome and Foxp3-deficient mice were analyzed by single-cell cytometry and RNA-sequencing, revealing heterogeneous Treg-like cells, some very similar to normal Treg cells, others more distant. Conventional T cells showed no widespread activation or helper T cell bias, but a monomorphic disease signature affected all CD4+ T cells. This signature proved to be cell extrinsic since it was extinguished in mixed bone marrow chimeric mice and heterozygous mothers of patients with IPEX syndrome. Normal Treg cells exerted dominant suppression, quenching the disease signature and revealing in mutant Treg-like cells a small cluster of genes regulated cell-intrinsically by FOXP3, including key homeostatic regulators. We propose a two-step pathogenesis model: cell-intrinsic downregulation of core FOXP3-dependent genes destabilizes Treg cells, de-repressing systemic mediators that imprint the disease signature on all T cells, furthering Treg cell dysfunction. Accordingly, interleukin-2 treatment improved the Treg-like compartment and survival.

Inflammatory Bowel Disease in Patients with Congenital Chloride Diarrhoea.

BACKGROUND: Congenital chloride diarrhoea [CLD] is a rare autosomal recessive disease caused by mutations in the solute family carrier 26 member 3 [SLC26A3] gene. Patients suffer from life-long watery diarrhoea and chloride loss. Inflammatory bowel disease [IBD] has been reported in individual patients with CLD and in scl26a3-deficient mice. METHODS: We performed an international multicentre analysis to build a CLD cohort and to identify cases with IBD. We assessed clinical and genetic characteristics of subjects and studied the cumulative incidence of CLD-associated IBD. RESULTS: In a cohort of 72 patients with CLD caused by 17 different SLC26A3 mutations, we identified 12 patients [17%] diagnosed with IBD. Nine patients had Crohn's disease, two ulcerative colitis and one IBD-unclassified [IBD-U]. The prevalence of IBD in our cohort of CLD was higher than the highest prevalence of IBD in Europe [p < 0.0001]. The age of onset was variable [13.5 years, interquartile range: 8.5-23.5 years]. Patients with CLD and IBD had lower z-score for height than those without IBD. Four of 12 patients had required surgery [ileostomy formation n = 2, ileocaecal resection due to ileocaecal valve stenosis n = 1 and colectomy due to stage II transverse colon cancer n = 1]. At last follow-up, 5/12 were on biologics [adalimumab, infliximab or vedolizumab], 5/12 on immunosuppressants [azathioprine or mercaptopurine], one on 5-ASA and one off-treatment. CONCLUSIONS: A substantial proportion of patients with CLD develop IBD. This suggests the potential involvement of SL26A3-mediated anion transport in IBD pathogenesis. Patients with CLD-associated IBD may require surgery for treatment failure or colon cancer.

Congenital Diarrhea and Cholestatic Liver Disease: Phenotypic Spectrum Associated with MYO5B Mutations.

Myosin Vb (MYO5B) is a motor protein that facilitates protein trafficking and recycling in polarized cells by RAB11- and RAB8-dependent mechanisms. Biallelic MYO5B mutations are identified in the majority of patients with microvillus inclusion disease (MVID). MVID is an intractable diarrhea of infantile onset with characteristic histopathologic findings that requires life-long parenteral nutrition or intestinal transplantation. A large number of such patients eventually develop cholestatic liver disease. Bi-allelic MYO5B mutations are also identified in a subset of patients with predominant early-onset cholestatic liver disease. We present here the compilation of 114 patients with disease-causing MYO5B genotypes, including 44 novel patients as well as 35 novel MYO5B mutations, and an analysis of MYO5B mutations with regard to functional consequences. Our data support the concept that (1) a complete lack of MYO5B protein or early MYO5B truncation causes predominant intestinal disease (MYO5B-MVID), (2) the expression of full-length mutant MYO5B proteins with residual function causes predominant cholestatic liver disease (MYO5B-PFIC), and (3) the expression of mutant MYO5B proteins without residual function causes both intestinal and hepatic disease (MYO5B-MIXED). Genotype-phenotype data are deposited in the existing open MYO5B database in order to improve disease diagnosis, prognosis, and genetic counseling.

Identifying Health Economic Considerations to Include in the Research Protocol of a Randomized Controlled Trial (the REDUCE-RISK Trial): Systematic Literature Review and Assessment.

BACKGROUND: The REDUCE-RISK trial was set up to compare the effectiveness of weekly subcutaneously administered methotrexate with daily oral azathioprine or 6-mercaptopurine in low-risk Crohn disease (CD) or subcutaneously administered adalimumab (ADA) in high-risk CD in a pediatric population (age 6-17 years). OBJECTIVE: The aim of this study is to perform a systematic review to provide input into the research protocol to gather the necessary information to improve the performance of an evidence-based economic evaluation when the trial is finished. METHODS: The Centre for Reviews and Dissemination (CRD) Health Technology Assessment (HTA) database, websites of HTA institutes, CRD's National Health Service Economic Evaluation Database, MEDLINE (OVID), and Embase databases were consulted to retrieve (reviews of) relevant economic evaluations. Studies were eligible if they included a pediatric or adult population with inflammatory bowel diseases (CD and ulcerative colitis [UC]) treated with ADA (Humira). There were no restrictions on the comparator. Only economic evaluations expressing outcomes in life years gained or quality-adjusted life years gained were selected. RESULTS: A total of 12 primary studies were identified. None of these studies included a pediatric population because of a lack of supporting trials. The economic evaluations identified in our systematic review indicate that ADA is an appropriate intervention for inclusion in such a trial. From a health economic point of view, it is important to make an incremental analysis comparing such an intervention with standard care and not immediately versus another (expensive) biological treatment. Information on the impact of children's school attendance and parents' productivity is currently lacking in economic evaluations, and none of the underlying trials measured quality of life (QoL) using a generic utility instrument. CONCLUSIONS: The review of the economic literature on ADA for the treatment of patients with CD supports the performance of a trial with biologicals in pediatric patients, including making a distinction according to disease severity. Conducting an economic literature review enabled us to decide which variables should be added to the research protocol from an economic point of view. Measurements for children's and parents' QoL (EuroQol 5-Dimension questionnaires), children's school attendance, and parents' productivity (WPAI-CD-CG questionnaire) were added to the research protocol. This will provide support for the calculation of the cost-effectiveness of the interventions evaluated in the REDUCE-RISK trial. TRIAL REGISTRATION: ClinicalTrials.gov NCT02852694; https://clinicaltrials.gov/ct2/show/NCT02852694.

Clinical Genomics for the Diagnosis of Monogenic Forms of Inflammatory Bowel Disease: A Position Paper From the Paediatric IBD Porto Group of European Society of Paediatric Gastroenterology, Hepatology and Nutrition.

BACKGROUND: It is important to identify patients with monogenic IBD as management may differ from classical IBD. In this position statement we formulate recommendations for the use of genomics in evaluating potential monogenic causes of IBD across age groups. METHODS: The consensus included paediatric IBD specialists from the Paediatric IBD Porto group of the European Society of Paediatric Gastroenterology, Hepatology and Nutrition (ESPGHAN) and specialists from several monogenic IBD research consortia. We defined key topics and performed a systematic literature review to cover indications, technologies (targeted panel, exome and genome sequencing), gene panel setup, cost-effectiveness of genetic screening, and requirements for the clinical care setting. We developed recommendations that were voted upon by all authors and Porto group members (32 voting specialists). RESULTS: We recommend next-generation DNA-sequencing technologies to diagnose monogenic causes of IBD in routine clinical practice embedded in a setting of multidisciplinary patient care. Routine genetic screening is not recommended for all IBD patients. Genetic testing should be considered depending on age of IBD-onset (infantile IBD, very early-onset IBD, paediatric or young adult IBD), and further criteria, such as family history, relevant comorbidities, and extraintestinal manifestations. Genetic testing is also recommended in advance of hematopoietic stem cell transplantation. We developed a diagnostic algorithm that includes a gene panel of 75 monogenic IBD genes. Considerations are provided also for low resource countries. CONCLUSIONS: Genomic technologies should be considered an integral part of patient care to investigate patients at risk for monogenic forms of IBD.

Physician Practice Patterns in Holding Inflammatory Bowel Disease Medications due to COVID-19, in the SECURE-IBD Registry.

BACKGROUND: We aimed to describe physician practice patterns in holding or continuing IBD therapy in the setting of COVID-19 infection, using the Surveillance Epidemiology of Coronavirus Under Research Exclusion for Inflammatory Bowel Disease [SECURE-IBD] registry. METHODS: IBD medications that were stopped due to COVID-19 were recorded in the SECURE-IBD registry in addition to demographic and clinical data. We conducted descriptive analyses to understand characteristics associated with stopping IBD medications in response to active COVID-19 infection. RESULTS: Of 1499 patients, IBD medications were stopped in 518 [34.6%] patients. On bivariate and multivariable analyses, a diagnosis of ulcerative colitis or IBD-unspecified was associated with a lower odds of stopping medication compared with Crohn's disease (adjusted odds ratio [aOR] 0.6, 95% confidence interval [CI] 0.48, 0.75). When evaluating specific medications, 5-aminosalicylic acid was more likely to be continued [p <0.001] whereas anti-tumour necrosis factor therapy and immunomodulator therapy were more likely to be stopped [global p <0.001]. Other demographic and clinical characteristics did not affect prescription patterns. CONCLUSIONS: IBD medications other than immunomodulators were continued in the majority of IBD patients with COVID-19, in the international SECURE-IBD registry. Future studies are needed to understand the impact of stopping or continuing IBD medications on IBD- and COVID-19 related outcomes.