The association of autoimmune diseases with pediatric ulcerative colitis does not influence its disease course.

OBJECTIVE: Ulcerative colitis (UC) is a chronic inflammatory condition. Previous reports suggested that UC may have a worse prognosis when associated with auto-immune diseases. We compared characteristics at diagnosis and natural history of the disease between classical ulcerative colitis (CUC) and UC associated with auto-immune diseases (CAI) in children. MATERIAL AND METHODS: In this study, 67 children followed for UC at Nancy University Hospital between 1993 and 2012 were included: 45 patients in the CUC group and 22 in the CAI group. RESULTS: Median follow-up was 4.8 years. Median age at diagnosis was 11.6 years in the CAI group and 9.8 years in the CUC group. Time between symptoms onset and diagnosis was broadly similar in the two groups (<3 months) and there were no significant differences regarding biological and histological findings. At 5 years, the need for corticosteroids and azathioprine did not differ between the CAI and the CUC groups. There was also no significant difference between the two groups regarding infliximab use at 1 and 5 years. CONCLUSIONS: In this pediatric study, CAI had similar characteristics at baseline as CUC. The course of CAI does not seem to be influenced by the presence of concomitant auto-immune diseases.

Zinc Therapy for Wilson Disease in Children in French Pediatric Centers.

BACKGROUND AND AIMS: Zinc therapy is considered a good option in Wilson disease (WD), as a first-line treatment in presymptomatic children and a maintenance therapy after the initial chelator therapy. The aim of the study was to determine the practical use of zinc treatment in French pediatric centers. METHODS: A national survey was conducted in the 6 French centers using zinc acetate to treat WD. Clinical and biological parameters, dosage, and outcome were recorded. RESULTS: A total of 26 children were reported to be treated with zinc acetate, alone or in association with chelators. Of the 9 children (35%) who received zinc alone as a first-line therapy, 2 were switched to D-penicillamine because of inefficacy and 7 remained on zinc alone, but serum transaminase levels normalized in only 4 of them. Five children (19%) were initially treated with zinc in association with D-penicillamine (n = 4) or Trientine (n = 1) with good efficacy. Among the 12 children (46%) who received zinc as a maintenance therapy after D-penicillamine, no relapse of hepatic cytolysis occurred during a median follow-up of 5.2 years, but 2 of them were switched to Trientine because of zinc-related adverse effects. Epigastric pain was observed in 4 children, and a gastric perforation occurred in 1 child. CONCLUSIONS: The present study demonstrates poor efficacy of zinc as first-line therapy to control liver disease in half presymptomatic children and a high incidence of related gastrointestinal adverse effects in children with WD.

IgE antibodies and skin tests in immediate hypersensitivity reactions to infliximab in inflammatory bowel disease: impact on infliximab retreatment.

BACKGROUND: Infliximab (IFX) is used for the treatment of inflammatory bowel diseases (IBD). Immediate hypersensitivity reactions (HR) to IFX are frequently reported. OBJECTIVES: We investigated immunoglobulin E (IgE)-mediated mechanisms underlying immediate HR to IFX. We also evaluated the clinical utility of allergological tests as well as the tolerability of IFX retreatment in these patients. METHODS: This was a prospective single-center study including IBD patients with previous immediate HR to IFX. Skin tests to IFX, including prick tests and intradermal tests, and measurement of anti-IFX IgE antibodies were performed at least 4 weeks after HR. In case of negative skin tests and absence of IgE antibodies, readministration of IFX was performed with a twice-reduced infusion rate. In case of positive tests or recurrence of HR during readministration of IFX, a 12-step desensitization or induction of tolerance protocol was proposed. RESULTS: A total of 24 IBD patients were included (Crohn's disease: n=20). Prick tests to IFX were all negative. Intradermal test was positive in one patient. Anti-IFX IgE antibodies were not detected in 21 patients and were detected in three patients (significant level in one patient and intermediate level in two patients). No relationship was observed between positive skin tests and the presence of anti-IFX IgE antibodies. Switch to adalimumab was well tolerated in 10/11 patients. The readministration of IFX was well tolerated in 4/11 patients. Desensitization to IFX was successful in three out of four patients. CONCLUSION: The vast majority of immediate HR to IFX is not IgE-mediated. Allergological tests are of poor clinical utility. Desensitization or induction of tolerance protocol may allow continuation of IFX therapy in IBD patients with a history of immediate HR.

Immune deficiency-related enteropathy-lymphocytopenia-alopecia syndrome results from tetratricopeptide repeat domain 7A deficiency.

BACKGROUND: Inflammatory bowel disease (IBD) is one of the most common chronic gastrointestinal diseases, but the underlying molecular mechanisms remain largely unknown. Studies of monogenic diseases can provide insight into the pathogenesis of IBD. OBJECTIVE: We thought to determine the underlying molecular causes of IBD occurring in 2 unrelated families in association with an immune deficiency. METHODS: We performed genetic linkage analysis and candidate gene sequencing on 13 patients from a large consanguineous family affected by early-onset IBD, progressive immune deficiency, and, in some cases, autoimmunity and alopecia, a condition we named enteropathy-lymphocytopenia-alopecia. The candidate gene was also sequenced in an unrelated patient with a similar phenotype. We performed histologic analysis of patients' intestinal biopsy specimens and carried out functional assays on PBMCs. Gut organoids derived from a patient's biopsy specimen were analyzed. RESULTS: We identified biallelic missense mutations in tetratricopeptide repeat domain 7A (TTC7A) in all patients from both families. The resulting TTC7A depletion modified the proliferation, adhesion, and migratory capacities of lymphocytes through inappropriate activation of the RhoA signaling pathway. Normal function was restored by wild-type TTC7A expression or addition of a RhoA kinase inhibitor. The growth and polarity of gut epithelial organoids were also found to be dependent on the RhoA signaling pathway. CONCLUSIONS: We show that TTC7A regulates the actin cytoskeleton dynamics in lymphocytes through the RhoA signaling pathway and is required in both lymphocytes and epithelial cells for maintaining equilibrium between cell proliferation, migration, polarization, and cell death. Our study highlights variability in the phenotypic expression resulting from TTC7A deficiency and outlines that impairment of both epithelial cells and lymphocytes cooperatively causes IBD.

Anastomotic ulcerations after intestinal resection in infancy.

OBJECTIVE: Anastomotic ulceration (AU) is a rare complication after intestinal resection and anastomosis, described mostly in children. The main symptom is occult bleeding, leading to iron-deficiency anemia, which is life threatening. METHODS: The present survey reports a series of patients with AU after intestinal resection in infancy, focusing on predictive factors, medical and surgical treatment options, and long-term outcomes. Eleven patients (7 boys) born between 1983 and 2005 with AU after an intestinal resection and anastomosis in infancy were included in this retrospective review. RESULTS: The diagnosis of AU was often delayed for several years. No predictive factor (including the primary disease, the length of the remnant bowel, and the loss of the ileocaecal valve) could be identified. Numerous treatment options, including antibiotics and anti-inflammatory drugs, proved to be ineffective to induce prolonged remission. Even after surgical resection, relapses were observed in 5/7 children. CONCLUSIONS: The mechanism leading to AU remains unknown. Contrary to previous reports with limited follow-up, no medical or surgical treatment could prevent recurrences. Because relapses may occur several years after treatment, long-term follow-up is needed.

Identification of a human splenic marginal zone B cell precursor with NOTCH2-dependent differentiation properties.

Mouse splenic marginal zone precursors (MZPs) differentiate into marginal zone B (MZB) cells under a signaling pathway involving Notch2 and its ligand, delta-like 1 ligand (Dll1). We report the identification of an MZP subset in the spleen of young children. These MZPs differentiate into MZ-like B cells in vitro in the presence of OP9 cells expressing human DLL1, as demonstrated by the up-regulation of classical MZB cell markers. A set of diagnostic genes discriminating IgM(+)IgD(+)CD27(+) blood and splenic MZB cells from switched B cells was identified (up-regulation of SOX7, down-regulation of TOX, COCH, and HOPX), and their expression during the induction assay mirrored the one of MZB cells. Moreover, Alagille patients with a NOTCH2 haploinsufficiency display a marked reduction of IgM(+)IgD(+)CD27(+) B cells in blood, whereas their switched memory B cells are not affected. Altogether, these results argue in favor of the existence of a rodent-like MZB cell lineage in humans.

Characteristics and management of congenital esophageal stenosis: findings from a multicenter study.

BACKGROUND: Congenital esophageal stenosis (CES) is a rare condition frequently associated with esophageal atresia (EA). There are limited data from small series about the presentation, treatment, and outcomes of CES. METHODS: Medical records of all patients with CES included in the French Network on Esophageal Malformations and Congenital Diseases were reviewed retrospectively with regard to diagnosis, treatment, and outcome. RESULTS: Over 18 years, 61 patients (30 boys) had CES, and 29 (47%) of these patients also had EA. The mean age at diagnosis was 24 months (1 day to 14 years) and was younger in patients with CES and EA than in those with isolated CES (7 vs. 126 months, p < 0.05). Twenty-one of the 61 patients with CES had no clinical symptoms: in three patients, the findings were incidental, and in 18 of the 29 patients with associated EA, CES was diagnosed at the time of surgical repair of EA or during a postoperative systematic esophageal barium study. In the 40 other patients, at diagnosis, 50% presented with dysphasia, 40% with vomiting, 50% with food impaction, and 42% with respiratory symptoms. Diagnosis of CES was confirmed by esophageal barium study (56/61) and/or esophageal endoscopy (50/61). Sixteen patients had tracheobronchial remnants (TBR), 40 had fibromuscular stenosis (FMS), and five had membrane stenosis (MS). Thirty-four patients (56%) were treated by dilation only (13/34 remained asymptomatic at follow-up); 15 patients were treated by dilation but required later surgery because of failure (4/15 remained asymptomatic at follow-up); and nine patients had a primary surgical intervention (4/9 were asymptomatic at follow-up). Dilation was complicated by esophageal perforation in two patients (3.4%). At follow-up, dysphagia remained in 36% (21/58) of patients, but the incidence did not differ between the EA and the isolated CS groups (10/29 vs. 7/32, p = 0.27). CONCLUSIONS: CS diagnosis can be delayed when associated with EA. Dilation may be effective for treating patients with FMS and MS, but surgical repair is often required for those with TBR. Our results show clearly that, regardless of the therapeutic option, dysphagia occurs frequently, and patients with CES should be followed over the long term.

Classification of and risk factors for hematologic complications in a French national cohort of 102 patients with Shwachman-Diamond syndrome.

BACKGROUND: Patients with the Shwachman-Diamond syndrome often develop hematologic complications. No risk factors for these complications have so far been identified. The aim of this study was to classify the hematologic complications occurring in patients with Shwachman-Diamond syndrome and to investigate the risk factors for these complications. DESIGN AND METHODS: One hundred and two patients with Shwachman-Diamond syndrome, with a median follow-up of 11.6 years, were studied. Major hematologic complications were considered in the case of definitive severe cytopenia (i.e. anemia <7 g/dL or thrombocytopenia <20 × 10(9)/L), classified as malignant (myelodysplasia/leukemia) according to the 2008 World Health Organization classification or as non-malignant. RESULTS: Severe cytopenia was observed in 21 patients and classified as malignant severe cytopenia (n=9), non-malignant severe cytopenia (n=9) and malignant severe cytopenia preceded by non-malignant severe cytopenia (n=3). The 20-year cumulative risk of severe cytopenia was 24.3% (95% confidence interval: 15.3%-38.5%). Young age at first symptoms (<3 months) and low hematologic parameters both at diagnosis of the disease and during the follow-up were associated with severe hematologic complications (P<0.001). Fifteen novel SBDS mutations were identified. Genotype analysis showed no discernible prognostic value. CONCLUSIONS Patients with Shwachman-Diamond syndrome with very early symptoms or cytopenia at diagnosis (even mild anemia or thrombocytopenia) should be considered at a high risk of severe hematologic complications, malignant or non-malignant. Transient severe cytopenia or an indolent cytogenetic clone had no deleterious value.

HLA-DQ genotyping combined with serological markers for the diagnosis of celiac disease: is intestinal biopsy still mandatory?

OBJECTIVES: The aim of this study was to evaluate the value of HLA-DQ2/DQ8 allelic genotyping combined with serologic testing for the diagnosis of celiac disease (CD). PATIENTS AND METHODS: One hundred seventy children, who underwent jejunal biopsy for digestive symptoms or malnutrition, were tested for HLA-DQ2/DQ8 and serologic markers (tTG and/or anti-endomysial antibodies). Children were classified in 2 groups, according to jejunal histology: group 1, when partial or total villous atrophy was associated with an increased intraepithelial lymphocytosis suggesting CD, and group 2, when these histological criteria were absent. RESULTS: Eight children were excluded from the study because their intestinal histology was not informative; 82 children were classified in group 1 and 80 in group 2. Eighty-one of 82 children in group 1 were positive for HLA and serologic testing. The other child had negative HLA and serologic testing but marked villous atrophy, and further investigation showed an allergic disease. Among the 80 children in group 2, 53 were negative for both HLA and serologic testing, 22 were positive for HLA but negative for serologic testing, 2 were negative for HLA and positive for serologic testing, and 3 patients were positive for both HLA and serologic testing. The last 3 children were shown to have an autoimmune background and had probably a latent form of CD. The association of HLA-DQ2/DQ8 and serologic markers had a sensitivity of 98.8%, a specificity of 96.2%, a positive likelihood ratio of 26.3, and a negative likelihood ratio of 0.013. CONCLUSIONS: The association of positive HLA-DQ2/DQ8 and serologic testing has a high predictive value for CD. We suggest that symptomatic children with high titers of immunoglobulin (Ig)A tTG could be diagnosed as patients with CD without performing jejunal biopsy. In other children, HLA-DQ2/DQ8 could be useful to exclude the diagnosis of CD if negative. In cases of low IgA tTG titers or in patients with IgA deficiency, intestinal biopsy remains mandatory.

Identification and functional consequences of a recurrent NLRP12 missense mutation in periodic fever syndromes.

OBJECTIVE: To gain insight into the molecular bases of genetically unexplained periodic fever syndromes (PFS) by screening NLRP12, a gene in which only a nonsense and a splice site mutation have so far been identified, and to assess the functional consequences of the identified missense variation. METHODS: NLRP12 was screened for mutations by direct sequencing. Functional assays were performed in HEK 293T cells stably expressing the proapoptotic protein ASC and procaspase 1, in order to determine the effects of normal and mutated NLRP12 proteins on speck formation, caspase 1 signaling, and NF-κB activation. RESULTS: A heterozygous NLRP12 missense mutation involving a CpG site (c.1054C>T; p.Arg352Cys) was identified in exon 3, which encodes the nucleotide-binding site (NBS) of the protein, in 2 patients from different countries and carrying different NLRP12 haplotypes. The mutation, which does not alter the inhibitory effect of NLRP12 on NF-κB activation, increases speck formation and activates caspase 1 signaling. To define this new class of PFS, we propose the term NLRP12-associated disorders (NLRP12AD). CONCLUSION: Given the rarity of known NLRP12-associated disorders, the identification of this NLRP12 molecular defect contributes to the delineation of the clinical spectrum associated with mutations in this gene and highlights the importance of screening NLRP12 in patients presenting with unexplained PFS. This study also demonstrates, by means of functional assays, the deleterious effect of this recurrent missense mutation; the gain of function for speck formation and caspase 1 signaling associated with this NBS mutation is consistent with the inflammatory phenotype of PFS.

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.

Molecular analysis and intestinal expression of SAR1 genes and proteins in Anderson's disease (Chylomicron retention disease).

BACKGROUND: Anderson's disease (AD) or chylomicron retention disease (CMRD) is a very rare hereditary lipid malabsorption syndrome. In order to discover novel mutations in the SAR1B gene and to evaluate the expression, as compared to healthy subjects, of the Sar1 gene and protein paralogues in the intestine, we investigated three previously undescribed individuals with the disease. METHODS: The SAR1B, SAR1A and PCSK9 genes were sequenced. The expression of the SAR1B and SAR1A genes in intestinal biopsies of both normal individuals and patients was measured by RTqPCR. Immunohistochemistry using antibodies to recombinant Sar1 protein was used to evaluate the expression and localization of the Sar1 paralogues in the duodenal biopsies. RESULTS: Two patients had a novel SAR1B mutation (p.Asp48ThrfsX17). The third patient, who had a previously described SAR1B mutation (p.Leu28ArgfsX7), also had a p.Leu21dup variant of the PCSK9 gene. The expression of the SAR1B gene in duodenal biopsies from an AD/CMRD patient was significantly decreased whereas the expression of the SAR1A gene was significantly increased, as compared to healthy individuals. The Sar1 proteins were present in decreased amounts in enterocytes in duodenal biopsies from the patients as compared to those from healthy subjects. CONCLUSIONS: Although the proteins encoded by the SAR1A and SAR1B genes are 90% identical, the increased expression of the SAR1A gene in AD/CMRD does not appear to compensate for the lack of the SAR1B protein. The PCSK9 variant, although reported to be associated with low levels of cholesterol, does not appear to exert any additional effect in this patient. The results provide further insight into the tissue-specific nature of AD/CMRD.

Fecal beta-defensin-2 in children with inflammatory bowel diseases.

Defensins, endogenous antibiotic peptides, are part of the intestinal epithelial barrier. In this pilot study we analyzed the possibility of measuring fecal beta-defensin-2 (HBD2) in comparing inflammatory and noninflammatory conditions. In samples from healthy control individuals, low levels of HBD2 were detectable, which markedly rose under inflammatory conditions (P = 0.0002 vs normal control individuals), the highest levels being observed in patients with ulcerative colitis (median 356 ng/g, range 40-527). Despite frank inflammation, Crohn disease patients with colitis had significantly lower, albeit enhanced, HBD2 levels than did ulcerative colitis patients. These data confirm the possibility of quantifying HBD2 in feces and indicate that colitis in Crohn disease and colitis in ulcerative colitis differ from each other with respect to their ability to secrete HBD2.

Efficacy of infliximab in pediatric Crohn's disease: a randomized multicenter open-label trial comparing scheduled to on demand maintenance therapy.

BACKGROUND: Infliximab (IFX) is efficacious in inducing remission in severe forms of pediatric Crohn's disease (CD). Adult studies indicate that IFX is also safe and well tolerated as maintenance therapy. The present study aimed to evaluate in a prospective manner the efficacy and safety of IFX as maintenance therapy of severe pediatric CD comparing scheduled and "on demand" treatment strategies. METHODS: Forty children with CD (nonpenetrating, nonstricturing as well as penetrating forms, mean age: 13.9 +/- 2.2 years) with a severe flare-up (Harvey-Bradshaw Index [HBI] > or =5, erythrocyte sedimentation rate [ESR] >20 mm/h) despite well-conducted immunomodulator therapy (n = 36 azathioprine, n = 1 mercaptopurine, n = 3 methotrexate) combined with steroids were included in this randomized, multicenter, open-label study. Three IFX infusions (5 mg/kg) were administered at week (W)0/W2/W6. At W10, clinical remission (HBI <5) and steroid withdrawal were analyzed and IFX responders were randomized to maintenance therapy over 1 year: group A, scheduled every 2 months; group B, "on demand" on relapse. RESULTS: In all, 34/40 children came into remission during IFX induction therapy (HBI: 6.7 +/- 2.5 (WO) vs. 1.1 +/- 1.5 (W10); P < 0.001). At the end of phase 2, 15/18 (83%) patients were in remission in group A compared to 8/13 (61%) children in group B (P < 0.01), with a mean HBI of 0.5 versus 3.2 points (group A versus B, P = 0.011). In group A, 3/13 (23.1%) children experienced a relapse compared to 11/12 (92%) children in group B. No severe adverse event occurred during this trial. CONCLUSIONS: IFX is well tolerated and safe as maintenance therapy for pediatric CD, with a clear advantage when used on a scheduled 2-month basis compared to an "on demand" basis.

Double-blind randomized evaluation of clinical and biological tolerance of polyethylene glycol 4000 versus lactulose in constipated children.

OBJECTIVES: To assess the safety of a polyethylene glycol (PEG) 4000 laxative without additional salts in pediatric patients. STUDY DESIGN: This was a 3-month multicenter, randomized, double-blind, double-dummy, lactulose-controlled, parallel study enrolling 96 ambulatory constipated children aged 6 months to 3 years, treated daily with 4-8 g PEG or 3.33 g-6.66 g lactulose. Total protein, albumin, iron, electrolytes, and vitamins B9 (folates), A and D (25OHD3) were measured in blood before and after treatment (day 84) in a central laboratory. RESULTS: The percentage of children with at least one value out of normal range at day 84 with respect to baseline status (with or without at least one value out of normal range), i.e. the primary endpoint, was 87% and 90% in the PEG and lactulose groups, respectively, without any difference between groups. The whole blood parameters showed no qualitative or quantitative treatment-related changes. Vitamin A values were above normal range in 56% and 41% of children at baseline versus 33% and 36% at day 84 in the PEG and lactulose groups, respectively. Iron values were similarly under normal range in 47% and 51% at baseline versus 42% and 51% at day 84. Clinical tolerance was similar for both treatments except for vomiting and flatulence, which were significantly higher with lactulose. Significantly higher improvements were evidenced with PEG regarding stool consistency, appetite, fecaloma and use of additional laxatives. CONCLUSION: This 3-month study in 96 constipated children aged 6 months to 3 years confirms the long-term tolerance of PEG 4000 in pediatrics and indicates a PEG efficacy similar to or greater than that of lactulose.

Efficacy and tolerance of infliximab in children and adolescents with Crohn's disease.

Infliximab, a monoclonal antibody against tumor necrosis factor-alpha, has been shown to be effective for the treatment of refractory Crohn's disease in adult patients, but experience in pediatrics is limited. This retrospective study included 88 children and adolescents, 39 girls and 49 boys, with a median age of 14 years (range 3.3-17.9). Infliximab was indicated for active disease (66%) and/or fistulas (42%) that were refractory to corticosteroids (70%), and/or other immunosuppressive (82%) agents, and/or parenteral nutrition (20%). Patients received 1 to 17 infusions (median 4) of 5 mg/kg (range 3.8-7.3) of infliximab during a median time period of 4 months (1-17 months). Infusion reaction was noted in 13 patients (15%), with a total of 16 reactions in 450 infusions (4%). At Day 90 after the first infusion of infliximab, symptoms improved in 49% of patients, whereas 29% of patients were in remission and 13% of patients relapsed. From Day 0 to Day 90, Harvey-Bradshaw score decreased from 7.5 to 2.8 (P < 0.001), C-reactive protein from 36 to 16 mg/L (P < 0.01), and 1-hour erythrocyte sedimentation rate from 35 to 17 mm (P < 0.01). Dosage of corticosteroids decreased from to 0.59 to 0.17 mg/kg/d (P < 0.001); 53% of patients could be weaned of corticosteroids and 92% of parenteral nutrition. Treatment with infliximab is well tolerated and effective in most children and adolescents with Crohn's disease that is refractory to conventional immunosuppressive therapy. Nevertheless, long-term efficacy remains to be shown, and further studies are urgently needed to precisely determine the best modality of continuing treatment.