Characterization of Biologic Discontinuation Among Pediatric Patients with Crohn's Disease.

BACKGROUND & AIMS: Biologic therapies may effectively treat Crohn's disease (CD), and pediatric patients who discontinue multiple biologics risk exhausting treatment options. The frequency and context of biologic discontinuation have not been well-characterized. We aimed to determine patterns of biologic use, discontinuation, and evaluation in pediatric patients with CD. METHODS: Pediatric patients with CD at 7 U.S. centers (2010-2020) were identified. Prospective ImproveCareNow registry data were supplemented with medical record abstraction. Biologics included monoclonal antibody and small molecule medications. Therapeutic drug monitoring (TDM) was considered induction if <14 weeks after biologic start, proactive if later during quiescent disease, and reactive during active disease. RESULTS: Of 823 patients included (median age, 13.0 years; 40% female), 86% started biologics (78% infliximab, 21% adalimumab, <1% others). Twenty-six percent used concomitant immunomodulators for ≥12 months. Most (85%) measured TDM including 47% induction, 69% proactive, and 24% reactive. Twenty-nine percent discontinued their first biologic after median 793 days because of inefficacy (34%), anti-drug antibodies (8%), adverse events (8%), or non-adherence (12%). If inefficacy, 86% underwent pre-discontinuation evaluation. If infliximab or adalimumab inefficacy and TDM was done, 62% had levels <10 µg/mL. Proactive TDM and concomitant immunomodulators were associated with 60% and 32% reduced biologic discontinuation. CONCLUSIONS: Most children with CD are treated with biologics; 25%-37% discontinue biologics, resulting in 1 in 12 using >2 biologics during pediatric care. Half of patients discontinued biologics without trial of high-dose therapy and 14% without any evaluation. Concomitant immunomodulator use and proactive TDM decreased risk of biologic discontinuation. Strategies are needed to preserve biologic efficacy and prevent biologic discontinuation.

Comparative Effectiveness of Anti-TNF in Combination With Low-Dose Methotrexate vs Anti-TNF Monotherapy in Pediatric Crohn's Disease: A Pragmatic Randomized Trial.

BACKGROUND & AIMS: Tumor necrosis factor inhibitors, including infliximab and adalimumab, are a mainstay of pediatric Crohn's disease therapy; however, nonresponse and loss of response are common. As combination therapy with methotrexate may improve response, we performed a multicenter, randomized, double-blind, placebo-controlled pragmatic trial to compare tumor necrosis factor inhibitors with oral methotrexate to tumor necrosis factor inhibitor monotherapy. METHODS: Patients with pediatric Crohn's disease initiating infliximab or adalimumab were randomized in 1:1 allocation to methotrexate or placebo and followed for 12-36 months. The primary outcome was a composite indicator of treatment failure. Secondary outcomes included anti-drug antibodies and patient-reported outcomes of pain interference and fatigue. Adverse events (AEs) and serious AEs (SAEs) were collected. RESULTS: Of 297 participants (mean age, 13.9 years, 35% were female), 156 were assigned to methotrexate (110 infliximab initiators and 46 adalimumab initiators) and 141 to placebo (102 infliximab initiators and 39 adalimumab initiators). In the overall population, time to treatment failure did not differ by study arm (hazard ratio, 0.69; 95% CI, 0.45-1.05). Among infliximab initiators, there were no differences between combination and monotherapy (hazard ratio, 0.93; 95% CI, 0.55-1.56). Among adalimumab initiators, combination therapy was associated with longer time to treatment failure (hazard ratio, 0.40; 95% CI, 0.19-0.81). A trend toward lower anti-drug antibody development in the combination therapy arm was not significant (infliximab: odds ratio, 0.72; 95% CI, 0.49-1.07; adalimumab: odds ratio, 0.71; 95% CI, 0.24-2.07). No differences in patient-reported outcomes were observed. Combination therapy resulted in more AEs but fewer SAEs. CONCLUSIONS: Among adalimumab but not infliximab initiators, patients with pediatric Crohn's disease treated with methotrexate combination therapy experienced a 2-fold reduction in treatment failure with a tolerable safety profile. CLINICALTRIALS: gov, Number: NCT02772965.

Very-Early Onset Chronic Active Colitis with Heterozygous Variants in LRBA1 and CARD11, a Case of "Immune TOR-Opathies".

BACKGROUND: A small subset of cases of inflammatory bowel disease (IBD) occurs as a result of single gene defects, and typically occurs in young or very young pediatric patients, referred to as "monogenic very-early onset IBD (VEO-IBD)". The gene variants leading to monogenic VEO-IBD are often associated with primary immunodeficiency syndromes. CASE REPORT: A six year-old girl presented to our gastroenterology clinic with LRBA deficiency with a heterozygous mutation at c.1399 A > G, p Met467Val, histopathologic chronic active colitis without granulomas and clinical chronic colitis. Her gastrointestinal symptoms began at age 5 with bloody diarrhea, abdominal pain and weight loss. Whole exome sequencing revealed a CARD11 heterozygous de novo mutation (c.220 + 1G > A). She was in clinical remission on only abatacept. DISCUSSION: We present a case of monogenic VEO-IBD associated with two heterozygous variants in LRBA1 and CARD11, both considered as key players in the newly proposed "immune TOR-opathies".

Immunosuppressant-associated eruptions in pediatric inflammatory bowel disease: A case-control study.

Paradoxically, immunosuppressive therapy for inflammatory bowel disease (IBD) can induce psoriasiform or eczematous eruptions. This case-control study identified infliximab exposure, Crohn's disease, and history of inflammatory skin conditions as significant risk factors for these eruptions in children with IBD. Our results also showed possible trends in age and race.

Evaluation of Nonalcoholic Fatty Liver Disease in Pediatric Patients With Inflammatory Bowel Disease.

ABSTRACT: Adult studies demonstrate the co-existence of nonalcoholic fatty liver disease (NAFLD) and inflammatory bowel disease (IBD) without traditional risk factors. Data in children with IBD are lacking. Here, we sought to establish the prevalence of NAFLD in a single-center pediatric IBD cohort, and identify potential risk factors. After institutional review board approval, we enrolled children with IBD who underwent routine abdominal magnetic resonance enterography. Proton density fat fraction (PDFF) was then estimated on magnetic resonance enterography. A total of 83 patients with IBD were identified and PDFF maps completed. Five (6%) were found to have PDFF >5%, meeting criteria for NAFLD. Compared to the patients with IBD without NAFLD, none of the evaluated risk factors including age, sex, diagnosis, time since diagnosis, medication, median alanine aminotransferase, and weight status were statistically significant. Our findings demonstrate the occult nature of NAFLD in pediatric IBD. The prevalence is not at variance with what is expected in general teenage populations.

Development and evaluation of an EHR-based computable phenotype for identification of pediatric Crohn's disease patients in a National Pediatric Learning Health System.

OBJECTIVES: To develop and evaluate the classification accuracy of a computable phenotype for pediatric Crohn's disease using electronic health record data from PEDSnet, a large, multi-institutional research network and Learning Health System. STUDY DESIGN: Using clinician and informatician input, algorithms were developed using combinations of diagnostic and medication data drawn from the PEDSnet clinical dataset which is comprised of 5.6 million children from eight U.S. academic children's health systems. Six test algorithms (four cases, two non-cases) that combined use of specific medications for Crohn's disease plus the presence of Crohn's diagnosis were initially tested against the entire PEDSnet dataset. From these, three were selected for performance assessment using manual chart review (primary case algorithm, n = 360, primary non-case algorithm, n = 360, and alternative case algorithm, n = 80). Non-cases were patients having gastrointestinal diagnoses other than inflammatory bowel disease. Sensitivity, specificity, and positive predictive value (PPV) were assessed for the primary case and primary non-case algorithms. RESULTS: Of the six algorithms tested, the least restrictive algorithm requiring just ≥1 Crohn's diagnosis code yielded 11 950 cases across PEDSnet (prevalence 21/10 000). The most restrictive algorithm requiring ≥3 Crohn's disease diagnoses plus at least one medication yielded 7868 patients (prevalence 14/10 000). The most restrictive algorithm had the highest PPV (95%) and high sensitivity (91%) and specificity (94%). False positives were due primarily to a diagnosis reversal (from Crohn's disease to ulcerative colitis) or having a diagnosis of "indeterminate colitis." False negatives were rare. CONCLUSIONS: Using diagnosis codes and medications available from PEDSnet, we developed a computable phenotype for pediatric Crohn's disease that had high specificity, sensitivity and predictive value. This process will be of use for developing computable phenotypes for other pediatric diseases, to facilitate cohort identification for retrospective and prospective studies, and to optimize clinical care through the PEDSnet Learning Health System.

Implementing a Novel Quality Improvement-Based Approach to Data Quality Monitoring and Enhancement in a Multipurpose Clinical Registry.

OBJECTIVE: To implement a quality improvement based system to measure and improve data quality in an observational clinical registry to support a Learning Healthcare System. DATA SOURCE: ImproveCareNow Network registry, which as of September 2019 contained data from 314,250 visits of 43,305 pediatric Inflammatory Bowel Disease (IBD) patients at 109 participating care centers. STUDY DESIGN: The impact of data quality improvement support to care centers was evaluated using statistical process control methodology. Data quality measures were defined, performance feedback of those measures using statistical process control charts was implemented, and reports that identified data items not following data quality checks were developed to enable centers to monitor and improve the quality of their data. PRINCIPAL FINDINGS: There was a pattern of improvement across measures of data quality. The proportion of visits with complete critical data increased from 72 percent to 82 percent. The percent of registered patients improved from 59 percent to 83 percent. Of three additional measures of data consistency and timeliness, one improved performance from 42 percent to 63 percent. Performance declined on one measure due to changes in network documentation practices and maturation. There was variation among care centers in data quality. CONCLUSIONS: A quality improvement based approach to data quality monitoring and improvement is feasible and effective.

Reduction of Computed Tomography Use for Pediatric Closed Head Injury Evaluation at a Nonpediatric Community Emergency Department.

OBJECTIVE: The purpose of this study was to determine if implementation of a Pediatric Emergency Care Applied Research Network (PECARN)-based Closed Head Injury Assessment Tool could safely decrease computed tomography (CT) use for pediatric head injury evaluation at a nonpediatric community emergency department (ED). METHODS: A quality improvement project was initiated at a nonpediatric community ED to implement an institution-specific, PECARN-based Pediatric Closed Head Injury Assessment Tool. Baseline head CT use at the participating ED was determined for children with closed head injury through retrospective chart review from March 2014 through November 2015. Head injury patients were identified using International Classification of Disease (ICD)-9 codes for head injury, unspecified (959.01) and concussion with and without loss of consciousness (850-850.9) until October 2015, after which ICD-9 was no longer used. To identify eligible patients after October 2015, lists of all pediatric patients evaluated at the participating ED were reviewed, and patients were included in the analysis if they had a physician-assigned discharge diagnosis of head injury or concussion. Exclusion criteria were age ≥ 18 years, penetrating head trauma, history of brain tumor, ventriculoperitoneal shunt, bleeding disorder, or presentation > 24 hours postinjury. Medical history, injury mechanism, symptoms, head CT use, and disposition were recorded. Implementation of the Pediatric Closed Head Injury Assessment Tool was achieved through provider education sessions beginning in December 2015 and ending in August 2016. Head CT use was monitored for 12 months postimplementation, from September 2016 through August 2017. Patients were classified into low, intermediate, or high risk for clinically important traumatic brain injury (ciTBI) by chart review. ED length of stay (LOS), disposition, and ED returns within 72 hours were recorded. Categorical variables were compared using chi-square test or Fisher's exact test, and continuous variables, using Kruskal-Wallis test. RESULTS: A total of 252 children with closed head injury were evaluated preimplementation (March 2014 through November 2015), 132 children were evaluated during implementation (December 2015 through August 2016), and 172 children were evaluated postimplementation (September 2016 through August 2017). Overall CT use decreased from 37.7% (95% confidence interval [CI] = 31.7-43.7) preimplementation to 16.9% (95% CI = 11.3-22.5) postimplementation (p < 0.001). Only 1% (95% CI = 0%-2.9%) of low-risk patients received a head CT postimplementation compared to 22.6% (95% CI = 16.1%-29.1%) preimplementation (p < 0.001). CT use among patients ≥ 24 months decreased from 42.9% (95% CI = 36.5%-49.6%) to 19.6% (95% CI = 13.1%-26.1%; p < 0.001) and remained low and unchanged for patients < 24 months. Transfers to a pediatric trauma center and ED returns within 72 hours were unchanged, while median ED LOS improved from 1.5 to 1.3 hours (p = 0.03). There were no missed ciTBIs after implementation of the guideline. CONCLUSION: Implementation of the PECARN-based Pediatric Closed Head Injury Assessment Tool reduced head CT use in a nonpediatric ED. The greatest impact was seen among children aged ≥ 24 months at very low risk for ciTBI.

Accuracy of the medication list in the electronic health record-implications for care, research, and improvement.

Objective: Electronic medication lists may be useful in clinical decision support and research, but their accuracy is not well described. Our aim was to assess the completeness of the medication list compared to the clinical narrative in the electronic health record. Methods: We reviewed charts of 30 patients with inflammatory bowel disease (IBD) from each of 6 gastroenterology centers. Centers compared IBD medications from the medication list to the clinical narrative. Results: We reviewed 379 IBD medications among 180 patients. There was variation by center, from 90% patients with complete agreement between the medication list and clinical narrative to 50% agreement. Conclusions: There was a range in the accuracy of the medication list compared to the clinical narrative. This information may be helpful for sites seeking to improve data quality and those seeking to use medication list data for research or clinical decision support.

Rapid Infliximab Infusion in Children with Inflammatory Bowel Disease: A Multicenter North American Experience.

BACKGROUND: Infliximab (IFX) infusion may lead to development of anti-IFX antibodies, and subsequent infusion reactions (IRs). The safety of rapid IFX infusion administered over 60 minutes has been under-investigated in children with inflammatory bowel disease. In a multicenter study, the frequency and nature of rapid infusion-associated IRs were examined. METHODS: The medical records of all consecutive children with inflammatory bowel disease receiving rapid IFX infusions between January 2014 and December 2016 were reviewed. Poisson regression analysis was used to identify possible associated factors with IRs. RESULTS: A total of 4120 rapid infusions for 453 children (median age 16 yrs [interquartile range 13.8-17.8], 289 males, 374 with Crohn's disease) were included. One hundred thirty-five participants (29.8%) received rapid IFX infusion for induction and maintenance while the rest received rapid IFX infusion after a median of 5 (interquartile range 4-9) standard infusions. The median dose of IFX using rapid protocol was 8 mg/kg/infusion (interquartile range 6-10). Two hundred sixty-seven (59%) patients received 1 or more premedications and 161 (35.5%) participants received concomitant immunosuppression. Twenty-one participants (4.6%) had IRs with rapid infusions and 2 participants discontinued IFX because of IRs (0.4%). Antihistamine premedications were associated with less frequent IR (adjusted relative risk = 0.30; 95% confidence interval, 0.14-0.64; P = 0.002). CONCLUSIONS: In children with inflammatory bowel disease, rapid IFX infusion administered over 60 minutes is safe and well-tolerated. Antihistamine premedications may reduce frequency of IRs (see Video Abstract, Supplemental Digital Content 1, http://links.lww.com/IBD/B632).

Serologic Evidence of Gut-driven Systemic Inflammation in Juvenile Idiopathic Arthritis.

OBJECTIVE: Accumulating evidence links juvenile idiopathic arthritis (JIA) to nonhost factors such as gut microbes. We hypothesize that children with new-onset JIA have increased intestinal bacterial translocation and circulating lipopolysaccharide (LPS). METHODS: We studied systemic treatment-naive patients with JIA [polyarticular JIA, n = 22, oligoarticular JIA, n = 31, and spondyloarthropathies (SpA), n = 16], patients with established inflammatory bowel disease-related arthritis (IBD-RA, n = 11), and 34 healthy controls. We determined circulating IgG reactivity against LPS, LPS-binding protein (LBP), α-1-acid glycoprotein (α-1AGP), and C-reactive protein (CRP) in plasma or serum from these patients and controls. Juvenile Arthritis Disease Activity Score (JADAS-27) was calculated for patients with JIA. RESULTS: Circulating anticore LPS antibody concentrations in patients with polyarticular JIA (p = 0.001), oligoarticular JIA (p = 0.024), and SpA (p = 0.001) were significantly greater than in controls, but there were no significant intergroup differences. Circulating LBP concentrations were also significantly greater in patients with polyarticular JIA (p = 0.001), oligoarticular JIA (p = 0.002), and SpA (p = 0.006) than controls, as were α-1AGP concentrations (p = 0.001, 0.001, and 0.003, respectively). No differences were observed between controls and patients with IBD-RA in any of the assays. Circulating concentrations of LBP and α-1AGP correlated strongly with CRP concentrations (r = 0.78 and r = 0.66, respectively). Anticore LPS antibody levels and CRP (r = 0.26), LBP (r = 0.24), and α-AGP (r = 0.22) concentrations had weaker correlations. JADAS-27 scores correlated with LBP (r = 0.66) and α-1AGP concentrations (r = 0.58). CONCLUSION: Children with polyarticular JIA, oligoarticular JIA, and SpA have evidence of increased exposure to gut bacterial products. These data reinforce the concept that the intestine is a source of immune stimulation in JIA.

Remission in Pediatric Inflammatory Bowel Disease Correlates With Prescription Refill Adherence Rates.

OBJECTIVES: The aim of the study was to use pharmacy benefit management (PBM) prescription claims data to assess refill adherence in pediatric inflammatory bowel disease (IBD) and correlate adherence with clinical outcomes in pediatric IBD. METHODS: We identified 362 pediatric patients with IBD seen at Washington University from 9/1/2012 to 8/31/2013 and matched them within Express Scripts' member eligibility files for clients allowing use of prescription drug data for research purposes. Maintenance IBD medication possession ratios (MPR) were determined through PBM prescription claims data and chart review. Demographic and prospectively captured physician global assessments (PGA) were retrospectively extracted from the medical record. MPR was analyzed as continuous data and also dichotomized as greater or less than 80%. RESULTS: Among our 362 patients, we matched 228 (63%) within Express Scripts' eligibility data files. Of those, 78 patients were continuously eligible for benefits and had at least one outpatient prescription IBD medication prescribed. Their mean MPR was 0.63 ±â€Š0.31 (standard deviation) and 40% had an MPR ≥80%. Patients in clinical remission had a higher mean MPR than those with an active PGA (0.72 ±â€Š0.28 vs 0.51 ±â€Š0.32, P = 0.002) and patients whose MPR were ≥80% were more likely to have a PGA of remission than those with whose MPR were <80% (84% vs 43%, P = <0.001). CONCLUSIONS: We found a significant association between refill adherence and clinical remission. Nonadherence was common and was more common in adolescents. Use of PBM databases to identify and intervene on patients with poor adherence may improve outcomes in pediatric IBD.

Application of Conjoint Analysis to Improve Reliability of Dietician Consultation in Pediatric Celiac Disease.

INTRODUCTION: Celiac disease (CD) management involves lifelong adherence to a gluten-free diet, making the dietician a key member in CD care. However, our institution lacked a standardized process for dietary consultation in newly diagnosed CD. METHODS: To understand provider CD care preferences, a 24-1 fractional factorial conjoint analysis was performed. Attributes studied (2 levels each) included type of initial follow-up gastroenterology (GI) provider, interval from diagnosis to follow-up, concurrence of initial dietary consultation with gastroenterology visit, and on-going follow-up GI provider. CD care was standardized in July 2014 to facilitate concurrent visits with the clinician and dietician during the same clinical session. Changes to mean time of dietary consultation and reliability of dietary consultation were monitored using an individual-control and G-control chart, respectively. Standard control chart rules were followed. RESULTS: Conjoint analysis identified shorter time to initial follow-up visit and concurrent GI/dietician visits as more important attributes in newly diagnosed CD subjects' care. Types of follow-up provider during first or subsequent visits were identified as less important attributes. After initiation of a standardized follow-up process, a special cause was identified in December 2015 with a decrease in the mean time to dietary consultation from 30 to 20 days. In addition, standardized follow-up resulted in a more reliable process as evident by a special cause on the G-control chart in February 2015. CONCLUSION: Conjoint analysis identified attributes thought to be important in CD follow-up care. After redesign of our care process, a decrease in time to dietary consultation with improved reliability was observed.

Improved outcomes with quality improvement interventions in pediatric inflammatory bowel disease.

OBJECTIVES: Variations in chronic illness care are common in our health care system and may lead to suboptimal outcomes. Specifically, inconsistent use and suboptimal medication dosing have been demonstrated in the care of patients with inflammatory bowel disease (IBD). Quality improvement (QI) efforts have improved outcomes in conditions such as asthma and diabetes mellitus, but have not been well studied in IBD. We hypothesized that QI efforts would lead to improved outcomes in our pediatric IBD population. METHODS: A QI team was formed within our IBD center in 2005. By 2007, we began prospectively capturing physician global assessment (PGA) and patient-reported global assessment. Significant QI interventions included creating evidence-based medication guidelines, joining a national QI collaborative, initiation of preclinic planning, and monitoring serum 25-hydroxyvitamin D. RESULTS: From 2007 to 2010, 505 patients have been followed at our IBD center. During this time, the frequency of patients in clinical remission increased from 59% to 76% (P < 0.05), the frequency of patients who report that their global assessment is >7 increased from 69% to 80% (P < 0.05), and the frequency of patients with a Short Pediatric Crohn's Disease Activity Index (sPCDAI) <15 increased from 60% to 77% (P < 0.05). The frequency of repeat steroid use decreased from 17% to 10% (P < 0.05). We observed an association between the use of a vitamin D supplement (P = 0.02), serum 25-hydroxyvitamin D (P < 0.05), and quiescent disease activity. CONCLUSIONS: Our results show that significant improvements in patient outcomes are associated with QI efforts that do not rely on new medication or therapies.

Budesonide use in pediatric Crohn disease.

BACKGROUND AND AIM: Budesonide (BUD) is being used in pediatric Crohn disease (CD) because it is believed to have the potential to reduce corticosteroid-related toxicity; however, few data are available describing its use. The aim of the present study was to describe BUD use in an inception cohort of pediatric patients with CD. METHODS: Data were derived from the prospective Pediatric IBD Collaborative Research Group Registry established in 2002 in North America. Use of BUD in children with CD was examined. RESULTS: BUD was used in 119 of 932 (13%) of children with newly diagnosed CD, with 56 of 119 (47%) starting BUD ≤ 30 days of diagnosis (26/56 with ileum and/or ascending colon [IAC] disease). BUD was used as monotherapy (9%), in combination with 5-aminosalicylates (77%), or in combination with immunomodulators (43%). Forty-three percent (24/56) went on to receive conventional corticosteroid at some point following their first BUD course. For the 63 of 119 (53%) who started BUD beyond the diagnosis period, 51 of 63 (81%) also received prednisone, with BUD used as a means of weaning from prednisone in 17 of 63 (27%). Patients with IAC disease who received BUD ≤ 30 days of diagnosis were just as likely to have received conventional corticosteroids by 1 year as were those who did not receive BUD ≤ 30 days of diagnosis. Two-thirds (77/119) of patients received BUD for ≤ 6 months. CONCLUSIONS: BUD is being used among pediatric patients newly diagnosed as having CD, although the majority does not have disease limited to the IAC. BUD monotherapy was rare, and further data are required to better define the role of BUD in the treatment of pediatric CD.

Granulocyte-macrophage colony stimulating factor blockade promotes ccr9(+) lymphocyte expansion in Nod2 deficient mice.

BACKGROUND: Ileal involvement in Crohn's disease (CD) is associated with NOD2 mutations and granulocyte-macrophage colony stimulating factor autoantibodies (GM-CSF Ab), and GM-CSF blockade promotes ileitis in Nod2/Card15-deficient (C15KO) mice. RALDH2-expressing dendritic cells (DC) and IL-4 promote CCR9 imprinting and small bowel homing of T lymphocytes, in conjunction with CCL25 expression by ileal epithelial cells (IEC). We hypothesized that GM-CSF neutralization promotes ileal disease by modulating expression of CCL25 by IEC and CCR9 by T lymphocytes via Nod2-dependent and independent pathways. METHODS: CCL25 and CCR9 expression were determined in pediatric CD patients stratified by GM-CSF Ab. Ileitis was induced in C15KO mice via GM-CSF Ab administration followed by nonsteroidal antiinflammatory drug (NSAID) exposure, and expression of CCL25, CCR9, FOXP3, intracellular cytokines, and RALDH2 was determined in IEC and immune cell populations. RESULTS: The frequency of CCL25(+) IEC and CCR9(+) T lymphocytes was increased in CD patients with elevated GM-CSF Ab. In the murine model, GM-CSF blockade alone induced IEC CCL25 expression, and reduced the frequency of mesenteric lymph node (MLN) CD4(+) FOXP3(+) cells, while Card15 deficiency alone enhanced MLN DC RALDH2 expression. Both GM-CSF neutralization and Card15 deficiency were required for downregulation of MLN DC IL-10 expression; under these conditions NSAID exposure led to an expansion of IL-4(+) and IL-17(+) CCR9(+) lymphocytes in the ileum. CONCLUSIONS: GM-CSF prevents ileal expansion of CCR9(+) lymphocytes via Nod2-dependent and independent pathways. CCR9 blockade may be beneficial in CD patients with elevated GM-CSF Ab.

Outcome following thiopurine use in children with ulcerative colitis: a prospective multicenter registry study.

OBJECTIVES: Despite little supporting data, thiopurine use is common in pediatric ulcerative colitis (UC). Our aim was to determine outcome following thiopurine use in a multicenter inception cohort of children diagnosed with UC. METHODS: Data were obtained from a prospective observational study of newly diagnosed children <16 years of age. Data are recorded at diagnosis, 30 days, and quarterly. Patients are managed by physician dictates not protocol. Disease activity is classified by physician global assessment. The primary outcome was corticosteroid (CS)-free inactive UC at 1 year following thiopurine initiation without the need for rescue therapy (infliximab, calcineurin inhibitors, or colectomy). RESULTS: Of 1,490 patients in our registry, 394 have UC (mean age at diagnosis 11.3±3.7 years); 197 (50%) received thiopurine (49% ≤3 months from diagnosis). Also, 84% were receiving CSs and 60% 5-aminosalicylates at thiopurine start. Of the 197 patients, there was insufficient follow-up (41), previous or concomitant use of infliximab (16), or calcineurin inhibitor (7), leaving 133 patients evaluable at 1 year. Of these, 65 (49%) had CS-free inactive UC without rescue therapy. CS-free inactive disease at 1 year after initiating thiopurine was not affected by starting thiopurine ≤3 months vs. >3 months from diagnosis, gender, age, or concomitant treatment with 5-aminosalicylates. Kaplan-Meier analysis showed that the likelihood of remaining free of rescue therapy in the thiopurine-treated patients was 73% at 1 year. CONCLUSIONS: Approximately 50% of children with UC starting thiopurine without previous or concomitant biologic or calcineurin inhibitor therapy have CS-free inactive disease 1 year later without the need for rescue therapy.

Presentation and outcome of histoplasmosis in pediatric inflammatory bowel disease patients treated with antitumor necrosis factor alpha therapy: a case series.

BACKGROUND: Antitumor necrosis factor alpha (aTNF) therapies are commonly used in the treatment of pediatric inflammatory bowel disease (IBD). However, inhibition of the TNF-alpha pathway predisposes to serious infections, including histoplasmosis, which is the most common invasive fungal infection in individuals on aTNF therapy and carries a high mortality rate when associated with delayed diagnosis. Few data exist on the frequency, presentation, and appropriate treatment of pediatric patients with histoplasmosis on aTNF therapy. METHODS: Following Institutional Review Board approval, cases were identified then reviewed with their primary gastroenterologist and infectious disease specialists. RESULTS: Herein we describe histoplasmosis in five pediatric patients receiving aTNF therapy for IBD in an endemic area. CONCLUSIONS: Histoplasmosis is an important complication of treatment with TNF-alpha neutralizing agents. Children with IBD treated with aTNF therapy who develop the infection may present with minimal pulmonary symptoms. While discontinuation of aTNF therapy is important initially, few data exist to determine when and how aTNF therapy can be reinstituted. Recognition of Histoplasma capsulatum is often delayed due to the overlap of symptoms with some of the extraintestinal manifestations of IBD and other more prevalent infectious complications.

Loss of GM-CSF signalling in non-haematopoietic cells increases NSAID ileal injury.

BACKGROUND: Administration of granulocyte-macrophage colony stimulating factor (GM-CSF) relieves symptoms in Crohn's disease (CD). It has been reported that reduced GM-CSF bioactivity is associated with more aggressive ileal behaviour and that GM-CSF-null mice exhibit ileal barrier dysfunction and develop a transmural ileitis following exposure to non-steroidal anti-inflammatory drugs (NSAIDs). STAT5 signalling is central to GM-CSF action. It was therefore hypothesised that GM-CSF signalling in non-haematopoietic cells is required for ileal homeostasis. METHODS: Bone marrow (BM) chimeras were generated by reconstituting irradiated GM-CSF receptor (gm-csfr) beta chain or GM-CSF (gm-csf) deficient mice with wild type BM (WTBM-->GMRKO and WTBM-->GMKO). Intestinal barrier function and the response to NSAID-induced ileal injury were examined. Expression of gm-csf, gm-csfr or stat5 in Caco-2 and HT-29 intestinal epithelial cell (IEC) lines was knocked down and the effect of GM-CSF signalling on IEC survival and proliferation was determined. RESULTS: Elevated levels of GM-CSF autoantibodies in ileal CD were found to be associated with dysregulation of IEC survival and proliferation. GM-CSF receptor-deficient mice and WTBM-->GMRKO chimeras exhibited ileal hyperpermeability. NSAID exposure induced a transmural ileitis in GM-CSF receptor-deficient mice and WTBM-->GMRKO chimeras. Transplantation of wild type BM into GM-CSF-deficient mice prevented NSAID ileal injury and restored ileal barrier function. Ileal crypt IEC proliferation was reduced in WTBM-->GMRKO chimeras, while STAT5 activation in ileal IEC following NSAID exposure was abrogated in WTBM-->GMRKO chimeras. Following knock down of gm-csf, gm-csfr alpha or beta chain or stat5a/b expression in Caco-2 cells, basal proliferation was suppressed. GM-CSF normalised proliferation of Caco-2 cells exposed to NSAID, which was blocked by stat5a/b RNA interference. CONCLUSIONS: Loss of GM-CSF signalling in non-haematopoietic cells increases NSAID ileal injury; furthermore, GM-CSF signalling in non-haematopoietic cells regulates ileal epithelial homeostasis via the STAT5 pathway. The therapeutic use of GM-CSF may therefore be beneficial in chronic ileitis associated with CD.

Granulocyte-macrophage colony-stimulating factor autoantibodies in murine ileitis and progressive ileal Crohn's disease.

BACKGROUND & AIMS: Genetic variations that affect innate immunity increase risk of ileal Crohn's disease (CD). However, the penetrance of susceptibility genes, including NOD2, is low, suggesting additional risk factors. Neutralizing autoantibodies (Ab) against granulocyte-macrophage colony-stimulating factor (GM-CSF Ab) reduce neutrophil antimicrobial function in patients with primary alveolar proteinosis (PAP). We investigated whether GM-CSF Ab regulates neutrophil function in CD. METHODS: Serum samples from 354 adult and pediatric patients with inflammatory bowel disease (IBD) were analyzed for GM-CSF Ab and IBD markers. Levels of GM-CSF Ab were compared with patients' CD features and neutrophil function. Intestinal barrier function and nonsteroidal anti-inflammatory drug (NSAID)-induced injury were assessed in GM-CSF-null and NOD2-null mice. RESULTS: Median GM-CSF Ab levels increased from 0.4 microg/mL in control serum to 2.4 microg/mL in pediatric CD and 11.7 microg/mL in adult CD serum and were associated with ileal involvement (P<.001). Ileal location, duration of disease, and increased GM-CSF Ab levels were associated with stricturing/penetrating behavior (odds ratio, 2.2; P=.018). The positive and negative predictive values of GM-CSF Ab for stricturing/penetrating behavior were comparable with that of other IBD serum markers. CD patients with increased GM-CSF Ab had reduced neutrophil phagocytic capacity and increased accumulation of pSTAT3+ neutrophils in the affected ileum. GM-CSF-null mice and NOD2-null mice in which GM-CSF was neutralized had defects in mucosal barrier function and developed a transmural ileitis following NSAID exposure. CONCLUSIONS: GM-CSF regulates ileal homeostasis in CD and in mouse models. CD patients with increases in serum GM-CSF Ab might benefit from GM-CSF administration.