Complicated Disease and Response to Initial Therapy Predicts Early Surgery in Paediatric Crohn's Disease: Results From the Porto Group GROWTH Study.

INTRODUCTION: The ability to predict risk for poor outcomes in Crohn's disease [CD] would enable early treatment intensification. We aimed to identify children with CD with complications at baseline and throughout the study period who are at risk for surgery 2 years from diagnosis. METHODS: Newly diagnosed children with CD were enrolled into a prospective, multicentre inception cohort. Disease characteristics and serological markers were obtained at baseline and week 12 thereafter. Outcome data including disease activity, therapies, complications and need for surgery were collected until the end of 104 weeks. A chi-square automatic interaction detection [CHAID] algorithm was used to develop a prediction model for early surgery. RESULTS: Of 285 children enrolled, 31 [10.9%] required surgery within 2 years. Multivariate analysis identified stricturing disease at baseline (odds ratio [OR] 5.26, 95% confidence interval [CI] 2.02-13.67 [p = 0.001]), and Paediatric Crohn's Disease Activity Index [PCDAI] >10 at week 12 (OR 1.06, 95% CI 1.02-1.10 [p = 0.005]) as key predictors for early surgery. CHAID demonstrated that absence of strictures at diagnosis [7.6%], corticosteroid-free remission at week 12 [4.1%] and early immunomodulator therapy [0.8%] were associated with the lowest risk of surgery, while stricturing disease at diagnosis [27.1%, p < 0.001] or elevated PCDAI at week 12 [16.7%, p = 0.014] had an increased risk of surgery at follow-up. Anti-OmpC status further stratified high-risk patients. DISCUSSION: A risk algorithm using clinical and serological variables at diagnosis and week 12 can categorize patients into high- and low-risk groups from diagnosis.

Pediatric autoimmune liver disease and extra-hepatic immune-mediated comorbidities.

BACKGROUND: Autoimmune liver disease (AILD) includes autoimmune hepatitis (AIH) and autoimmune sclerosing cholangitis (ASC). AILD is often associated with other extra-hepatic immune-mediated disorders (EDs), but there are few pediatric studies available to date. In this study we evaluated the association between AILD and EDs in our pediatric series. METHODS: In this single centre retrospective study 48 patients (39 AIH and 9 ASC children) were evaluated. Thirty-six children were primarily referred to our Centre for liver disease suspicion, while the remaining twelve had a previous diagnosis of EDs. All the patients were screened for various EDs at AILD diagnosis and yearly during the follow-up. RESULTS: Mean duration of follow-up was 9 years and 1 month. Twenty-two (46%) patients had a diagnosis of EDs. Ulcerative colitis (UC) was the most frequent EDs (9 patients), followed by autoimmune thyroid disease (5 patients) and celiac disease (5 patients). In 7 out of 9 UC patients, ASC was present. CONCLUSIONS: Our study showed a high association (46%) between AILD and EDs. In particular, in 8 out of 9 ASC patients UC was diagnosed (p-value 0.007). It is important to look for EDs in AILD children and, conversely, AILD in EDs children with abnormal liver function tests.

Response to treatment is more important than disease severity at diagnosis for prediction of early relapse in new-onset paediatric Crohn's disease.

BACKGROUND: Paediatric Crohn's disease is characteried by frequently relapsing disease which may lead to hospitalisations and complications. AIM: To develop predictive models for early relapse following first remission. METHODS: The GROWTH CD prospective inception cohort was designed to predict risk for early disease relapse and poor outcomes. Newly diagnosed children underwent endoscopies and imaging. They were phenotyped and followed at scheduled visits through 78 weeks for relapses. Twenty-eight dichotomous and continuous variables were assessed at baseline and week 12, including phenotype, inflammatory markers, disease activity (PCDAI) and other markers. Clinical relapses defined as PCDAI >10 after remission were recorded using a relapse form. Logistic regression & risk modelling was performed. RESULTS: We enrolled 282 eligible patients of whom 178 (63.6%) patients achieved steroid free remission by week 12. Disease complications developed in 22/76(29%) of patients with relapse compared to 20/206 (9.7%) without relapse (P = 0.01). Multivariable analysis demonstrated that while variables from age/gender at diagnosis were not predictive, week 12 variables including PCDAI >5 (P = 0.02), CRP >20 mg/L (P = 0.02), and faecal calprotectin >400 µg/g (P = 0.03) as optimal cut-offs were associated with increased risk of relapse. A prediction model for patients in remission including gender, age, week 12 PCDAI, calprotectin and CRP had sensitivity 43%, specificity 92%, PPV 78%, NPV 71% for relapse. CONCLUSIONS: Early relapses were associated with a higher risk for disease complications at followup. Relapse prediction based on week 12 disease activity or inflammation is superior to prediction using data from diagnosis.

Differences in Outcomes Over Time With Exclusive Enteral Nutrition Compared With Steroids in Children With Mild to Moderate Crohn's Disease: Results From the GROWTH CD Study.

BACKGROUND: Exclusive enteral nutrition [EEN] and corticosteroids [CS] induce similar rates of remission in mild to moderate paediatric Crohn's disease [CD], but differ with regard to mucosal healing. Our goal was to evaluate if EEN at diagnosis was superior to CS for improving long-term outcomes. METHODS: We prospectively followed newly diagnosed children aged < 17 years, with mild to moderate CD at baseline, for 2 years in the GROWTH CD study. Patients were evaluated at baseline and at 8, 12, 78, and 104 weeks. Remission, relapses, complications [fibrostenotic disease, penetrating disease, and active perianal disease] and growth were recorded throughout the study. A propensity score analysis was performed. RESULTS: A total of 147 children [mean age 12.9 ± 3.2 years], treated by EEN [n = 60] or CS [n = 87] were included. New complications developed in 13.7% of CS [12/87] versus 11.6% of EEN [7/60], p = 0.29. Remission was achieved in 41/87 [47%] in CS and 38/60 [63%] EEN, p = 0.036. Median time to relapse did not differ [14.4 ± 1 months with CS, 16.05 ± 1.1 EEN, p = 0.28]. Mean height Z scores decreased from Week 0 to Week 78 with CS [-0.34 ± 1.1 to -0.51 ± 1.2, p = 0.01], but not with EEN [-0.32 ± 1.1 to -0.22 ± 0.9, p = 0.56]. In a propensity score analysis, EEN was superior to CS for inducing remission [p = 0.05] and trended to superiority for height Z score [p = 0.055]. CONCLUSIONS: Use of EEN was associated with higher remission rates and a trend toward better growth but with similar relapse and complication rates in new-onset mild to moderate paediatric CD.

Looking Beyond Mucosal Healing: Effect of Biologic Therapy on Transmural Healing in Pediatric Crohn's Disease.

BACKGROUND: Crohn's disease is a chronic inflammatory disease characterized by a progressive transmural bowel damage leading to complications. Anti-TNFα therapy is effective in achieving mucosal healing (MH), but its efficacy on transmural inflammation has been poorly investigated. The aim of this study is to evaluate, in pediatric Crohn's disease, the efficacy of anti-tumor necrosis factor α agents in inducing transmural healing (TH) as assessed by ultrasonography (US). METHODS: Children with Crohn's disease requiring anti-tumor necrosis factor α therapy were prospectively enrolled. Clinical activity, laboratory tests, endoscopic activity, and transmural disease assessed by small intestine contrast US (SICUS) were evaluated at baseline (T0) and then after 9 to 12 months of therapy (T1). We evaluated US quantitative and qualitative parameters: disease extension (centimeters), bowel wall (BW) thickness >3 mm, BW vascularity and stratification strictures, and prestenotic dilatation. TH was defined as a BW thickness <3 mm and normalization of all US parameters at T1. RESULTS: Thirty-two patients were included. Patients with mucosal healing (MH) showed a significant decrease of BW thickness and disease extension at T1 (4.3 ± 1.4 mm and 8 ± 6.3 cm versus 6.1 ± 2.3 mm and 13 ± 5 cm at baseline, respectively) (P < 0.001). Increased vascularity of the BW was found in 80% of patients at T0 and in 18% at T1 (P < 0.001). These parameters did not change in patients without MH, despite clinical and laboratory remission. The presence of stenosis and prestenotic dilatation did not modify in any group. A complete TH was achieved in 14% of patients, all of them showing complete MH. CONCLUSIONS: Biologics induce clinical and laboratory remission and MH in pediatric CD. Although caution is needed due to the small sample size, our data suggest that transmural inflammation also improves during therapy, but a complete TH is achieved only in a small percentage of patients.

Prospective Evaluation of the Achievement of Mucosal Healing with Anti-TNF-α Therapy in a Paediatric Crohn's Disease Cohort.

BACKGROUND AND AIMS: There is growing evidence that in Crohn's disease the achievement and maintenance of mucosal healing (MH) through anti-TNFα antibodies may change the natural history of the disease. Few studies evaluating such outcome as a therapeutic goal are available in paediatrics. The primary aim of the study was to assess the efficacy of biologics in obtaining MH in a paediatric Crohn's disease cohort. The secondary aims were: (1) to assess response based on early or late treatment introduction and on combination therapy with immunomodulators versus biologics alone; and (2) to evaluate clinical outcome 2 years after the second endoscopy. METHODS: Biologic-naive paediatric Crohn's disease patients starting anti-tumour necrosis factor α (TNFα) treatment were enrolled. Patients' demographic and treatment data were recorded. Clinical [Pediatric Crohn's Disease Activity Index (PCDAI)] and endoscopic [Simple Endoscopic Score for Crohn's Disease (SES-CD)] evaluations were performed at time 0 (T0) and after 9-12 months (follow-up). Appropriate induction and maintenance therapeutic schemes were applied. RESULTS: Thirty-seven patients were enrolled. At enrolment, mean age was 12.3 ± 3.4 years and mean disease duration was 13.0 ± 16 months. At follow-up there was a significant decrease in PCDAI and SES-CD compared with T0 (p < 0.01). No statistical difference in frequency of MH between the early and late treatment introduction groups was found. Combination therapy was superior in obtaining complete plus partial MH (p < 0.01). One and 2 years after the second endoscopy, all and 79% of patients with complete MH and 75 and 67% of those with partial MH were still in clinical remission, respectively. CONCLUSIONS: Biologics improve mucosal lesions, apparently more effectively if given in combination with immunomodulators. MH appears to sustain a better disease course.

Adalimumab for the treatment of pediatric Crohn's disease.

Inflammatory bowel diseases are characterized by a chronic relapsing course, high morbidity and impaired quality of life. Their incidence is rising, and about 25% of cases are diagnosed in pediatric age. Anti-TNF-α antibodies, such as infliximab and adalimumab (ADA), are usually administered in patients refractory to conventional therapies. However, increasing evidence suggests that they can be introduced earlier in the course of the disease, especially in patients with aggressive and extensive disease since diagnosis. ADA is a fully human anti-TNF-α antibody recently approved for pediatric Crohn's disease not only in patients unresponsive to infliximab, but also as a first-line anti-TNF-α therapy. In this review, we aim to summarize the current knowledge on the use of ADA in pediatric Crohn's disease and to discuss open issues regarding safety as well as future perspectives.

Long-term safety of immunomodulators in pediatric inflammatory diseases.

The medical management of chronic inflammatory disorders in children, including mainly inflammatory bowel diseases and rheumatic diseases, has evolved dramatically over recent years with the advent of disease-modifying drugs such as immunomodulators and biological agents capable of interrupting the inflammatory cascade underlying these disorders. These agents are generally administered in patients who are refractory to conventional therapies. However, there is growing support that their use in the initial phases of these disorders, especially in pediatric patients, could interrupt and cease the inflammatory process. Thus, the aims of therapy have transitioned from symptomatic control to the achievement of deeper remission, including the healing of the inflammatory lesions combined with symptomatic remission. Therefore, more patients are currently receiving immunomodulators or biologics, frequently in addition to corticosteroids. Immunosuppression due to these therapies increases safety concerns, particularly regarding the risk of infections and malignancies. The available literature highlights how the combination of more than one of these therapies, especially if the combination includes corticosteroids, amplifies the risk of severe opportunistic infections. Otherwise, the infections described are mainly mild. Regarding malignancies, the overall risk associated with treatment appears non-significant in pediatric populations, but an appropriate benefit/risk assessment is recommended prior to the introduction of aggressive treatments such as immunomodulants and biologics. The background cancer risk related to the disease itself remains an issue. Protracted follow-up programs are needed, and the results from international multicenter registries are awaited to better understand the true risk related to therapy of these pediatric populations.

Role of HMGB1 as a suitable biomarker of subclinical intestinal inflammation and mucosal healing in patients with inflammatory bowel disease.

BACKGROUND: Noninvasive biomarkers of high- and low-grade intestinal inflammation and of mucosal healing (MH) in patients with inflammatory bowel disease are currently lacking. We have recently shown that fecal high mobility group box 1 (HMGB1) protein is a novel biomarker of gut inflammation. We aimed at investigating in a mouse model if HMGB1 was able to foresee both a clinically evident and a subclinical gut inflammation and if its normalization indicated MH. We also aimed at confirming the results in patients with Crohn's disease (CD) and ulcerative colitis. METHODS: C57BL6/J mice were treated with increasing doses of dextran sodium sulphate to induce colitis of different severity degrees; 28 with CD, 23 with ulcerative colitis, and 17 controls were also enrolled. Fecal HMGB1 was analyzed by enzyme-linked immunosorbent assay and immunoblotting. RESULTS: Fecal HMGB1 increased by 5-, 11-, 18-, and 24-folds with dextran sodium sulphate doses of 0.25%, 0.50%, 1%, and 4%, respectively, showing that the protein detected a high-grade and a subclinical inflammation. After a recovery time of 4-week posttreatment, HMGB1 returned to control levels, paralleling MH. In patients, fecal HMGB1 significantly correlated with endoscopic indexes (Simple Endoscopic Score for Crohn's Disease [SES-CD], endoscopic Mayo subscore), but not with the disease activity indexes (Crohn's disease Activity Index, partial Mayo score). CONCLUSIONS: Fecal HMGB1 is a robust noninvasive biomarker of clinically overt and subclinical gut inflammation; it can also be a surrogate marker of MH. We suggest the use of fecal HMGB1 to monitor the disease course and assess therapy outcomes in inflammatory bowel disease.

Bowel preparations for colonoscopy: an RCT.

BACKGROUND: The ideal preparation regimen for pediatric colonoscopy remains elusive, and available preparations continue to represent a challenge for children. The aim of this study was to compare the efficacy, safety, tolerability, and acceptance of 4 methods of bowel cleansing before colonoscopy in children. METHODS: This randomized, investigator-blinded, noninferiority trial enrolled all children aged 2 to 18 years undergoing elective colonoscopy in a referral center for pediatric gastroenterology. Patients were randomly assigned to receive polyethylene glycol (PEG) 4000 with simethicon (PEG-ELS group) or PEG-4000 with citrates and simethicone plus bisacodyl (PEG-CS+Bisacodyl group), or PEG 3350 with ascorbic acid (PEG-Asc group), or sodium picosulfate plus magnesium oxide and citric acid (NaPico+MgCit group). Bowel cleansing was evaluated according to the Boston Bowel Preparation Scale. The primary end point was overall colon cleansing. Tolerability, acceptability, and compliance were also evaluated. RESULTS: Two hundred ninety-nine patients were randomly allocated to the 4 groups. In the per-protocol analysis, PEG-CS+Bisacodyl, PEG-Asc, and NaPico+MgCit were noninferior to PEG-ELS in bowel-cleansing efficacy of both the whole colon (P = .910) and colonic segments. No serious adverse events occurred in any group. Rates of tolerability, acceptability, and compliance were significantly higher in the NaPico+MgCit group. CONCLUSIONS: Low-volume PEG preparations (PEG-CS+Bisacodyl, PEG-Asc) and NaPico+MgCit are noninferior to PEG-ELS in children, representing an attractive alternative to high-volume regimens in clinical practice. Because of the higher tolerability and acceptability profile, NaPico+MgCit would appear as the most suitable regimen for bowel preparation in children.

Ultrasonography of the colon in pediatric ulcerative colitis: a prospective, blind, comparative study with colonoscopy.

OBJECTIVES: To evaluate the usefulness of colonic ultrasonography (US) in assessing the extent and activity of disease in pediatric ulcerative colitis (UC) and to compare US findings with clinical and endoscopic features. STUDY DESIGN: Consecutive pediatric patients (n = 60) with a diagnosis of UC and suspected disease flare-up were prospectively enrolled; of these, 50 patients were eligible for the study. All underwent clinical evaluation, bowel US with color Doppler examination and colonoscopy. Blind US was performed the day before endoscopy in all patients. The US assessed variables were bowel wall thickness >3 mm, bowel wall stratification, vascularity, presence of haustra coli, and enlarged mesenteric lymph nodes. RESULTS: The endoscopic extent of disease was independently confirmed in 47 patients by US that yielded a 90% concordance with endoscopy (95% CI 0.82-0.96). Multiple regression analysis showed that US measurements with an independent predictive value of severity at endoscopy were increased bowel wall thickness (P < .0008), increased vascularity (P < .002), loss of haustra (P = .031), and loss of stratification of the bowel wall (P = .021). Each variable was assigned a value of 1 if present. The US score strongly correlated with clinical (r = 0.94) and endoscopic activity (r = 0.90) of disease (P < .0001). CONCLUSIONS: Colonic US is a useful first line noninvasive tool to assess the extent and activity of disease in children with UC and to estimate the severity of a flare-up, prior to further invasive tests.

Advances in the medical management of paediatric IBD.

IBD includes two classic entities, Crohn's disease and ulcerative colitis, and a third undetermined form (IBD-U), characterized by a chronic relapsing course resulting in a high rate of morbidity and impaired quality of life. Children with IBD are vulnerable in terms of growth failure, malnutrition and emotional effects. The aims of therapy have now transitioned from symptomatic control to the achievement of mucosal healing and deep remission. This type of therapy has been made possible by the advent of disease-modifying drugs, such as biologic agents, which are capable of interrupting the inflammatory cascade underlying IBD. Biologic agents are generally administered in patients who are refractory to conventional therapies. However, there is growing support that such agents could be used in the initial phases of the disease, typically in paediatric patients, to interrupt and cease the inflammatory process. Until several years ago, most therapeutic programmes in paediatric patients with IBD were borrowed from adult trials, whereas paediatric studies were often retrospective and uncontrolled. However, guidelines on therapeutic management of paediatric IBD and controlled, prospective, randomized trials including children with IBD have now been published. Here, the current knowledge concerning treatment options for children with IBD are reported. We also highlight the effectiveness and safety of new therapeutic advances in these paediatric patients.

Biological therapy in a pediatric Crohn disease population at a referral center.

OBJECTIVE: The antitumor necrosis factor α (TNFα) antibodies infliximab and adalimumab are effective in inducing and maintaining remission in pediatric patients with Crohn disease (CD). The aim of the study was to evaluate the long-term efficacy and safety of biological therapy in pediatric patients with CD followed at a referral center. METHODS: This work is a retrospective observational study enrolling patients with CD treated with infliximab or adalimumab beyond the induction protocol. The patients' data were collected from the unit's IBD database (maximum follow-up evaluation after 36 months of treatment). The efficacy was evaluated by the Pediatric Crohn Disease Activity Index score and by analysis of the cumulative probability of continuing therapy; the safety was assessed in terms of adverse events. RESULTS: We enrolled 78 patients; the mean therapy duration was 27.2 ± 16.7 months, and the mean age at enrollment was 15 ± 3.1 years. The Kaplan-Meier analysis showed a cumulative probability of continuing therapy of 81%, 54%, and 33% at 1, 2, and 3 years, respectively, from the introduction of therapy. No association between the patients' baseline characteristics and the long-term outcome was found. The evaluation of the concomitant therapy with immunomodulators and anti-TNFα therapy versus anti-TNFα alone did not show a different outcome. No serious adverse events were recorded. CONCLUSIONS: The study indicates that biological therapy is effective and safe in pediatric patients with CD in a longer follow-up period. The response to treatment was not influenced by the patients' baseline characteristics or by the immunomodulator association.

Presenting features and disease course of pediatric ulcerative colitis.

UNLABELLED: Clinical variables and disease course of pediatric ulcerative colitis (UC) have been poorly reported. The aim of this study was to retrospectively describe the phenotype and disease course of pediatric onset UC diagnosed at a tertiary referral Center for Pediatric Gastroenterology. PATIENTS AND METHODS: 110 patients with a diagnosis of UC were identified at our Department database. Records were reviewed for disease location and behavior at the diagnosis, family history for inflammatory bowel disease, pattern changes at the follow-up, need of surgery and cumulative risk for colectomy. RESULTS: Thirty-five % of patients had an early-onset disease (0-7 years). At the diagnosis, 29% had proctitis, 22% left-sided colitis, 15% extensive colitis and 34% pancolitis. Fifteen % presented with a rectal sparing, while a patchy colonic inflammation was reported in 18%. Rectal sparing was significantly related to the younger age (p: <0.05). Disease extension at the follow up was reported in 29% of pts. No clinical variables at the diagnosis were related to the subsequent extension of the disease. The cumulative rates of colectomy were 9% at 2 year and 14% at 5 years. An extensive disease as well as acute severe colitis and corticosteroid therapy at the diagnosis were significantly associated with an increased risk of colectomy. CONCLUSIONS: Pediatric UC is extensive and severe at the diagnosis, with an overall high rate of disease extension at the follow-up. Endoscopic atypical features are common in young children. The colectomy rate is related to the location and severity of the disease at the diagnosis.

Disease course and efficacy of medical therapy in stricturing paediatric Crohn's disease.

BACKGROUND: Stricturing is the most common complicated phenotype in paediatric Crohn's disease, but only few studies have described its course, while data on the outcome of medical treatment are scanty. AIM: To retrospectively describes the course of paediatric stricturing Crohn's disease and assess clinical and imaging response to medical therapy. PATIENTS AND METHODS: Thirty-six patients with stricturing Crohn's disease were identified by our department database. Paediatric Crohn's disease activity index, need of surgery and magnetic resonance were evaluated as outcomes at 6, 12, 18 and 24 months after detection of stenosis. RESULTS: Strictures were ileal, ileocolonic and colonic in 61%, 28% and 11% of patients. Thirteen (36%) had stricturing disease at the diagnosis of Crohn's disease, while 64% developed it at the follow-up. At baseline, 89% had medical treatment, while 11% surgery. At 6, 12, 18, and 24 months, 53%, 50%, 42%, and 35% had complete response to medical treatment, respectively. Overall, 44% were unresponsive to medical therapy and required surgery at the follow-up. Responders and non-responders significantly differed for inflammatory imaging findings at the stenosis detection. CONCLUSIONS: A stricturing phenotype is not uncommon at the diagnosis of Crohn's disease in children. Medical therapy seems poorly effective in avoiding intestinal resection. Magnetic resonance imaging is valuable in identifying patients who will benefit from medical therapy.

A potential role of Escherichia coli pathobionts in the pathogenesis of pediatric inflammatory bowel disease.

Through genomic analysis of mucosa-associated Escherichia coli strains, we found a close genetic association among isolates from pediatric inflammatory bowel disease (IBD) patients. A specific E. coli pathovar, adherent-invasive E. coli (AIEC), was found in Crohn's disease (CD) adult patients - this pathovar has enhanced adhesive and invasive properties, mainly due to the mannose-bonding FimH protein. We aimed to characterize 52 mucosa-associated E. coli strains isolated from pediatric IBD and non-IBD patients. Eleven E. coli strains, showing a strong similarity in fimH gene sequence to that of E. coli AIEC LF82, were characterized for fimH gene sequence, genomic profiling, adhesive and invasive ability, and phylogrouping. The results were compared with E. coli strains AIEC LF82 and MG1655. The 11 E. coli isolates showed 82.4% ± 1.4% fimH sequence similarity and 80.6% ± 1.3% genomic similarity to strain AIEC LF82. All these strains harbored V27A and S78N FimH mutations, as found in LF82. Nine of them belonged to the more virulent B2 and D phylogroups. Neuraminidase treatment, mimicking inflamed mucosa, enhanced adhesion of all 11 strains by 3.5-fold, but none showed invasion ability. It could be argued that the 11 selected strains could be a branch of an E. coli subpopulation (pathobionts), that could take advantage in an inflamed context because of a suitable genomic and (or) genetic backdrop.

Limitations of fecal calprotectin at diagnosis in untreated pediatric Crohn's disease.

BACKGROUND: Fecal Calprotectin (FC) is a validated screening test for intestinal inflammation in Crohn's disease (CD). The objective of the study was to prospectively evaluate the limitations of FC for identifying CD in newly diagnosed untreated pediatric patients and to assess the association of FC levels with disease location and serum inflammatory markers. METHODS: Consecutive children with new onset untreated CD participating in the ongoing ESPGHAN GROWTH CD study were evaluated at diagnosis for disease activity, extent, C-reactive protein (CRP), and FC. RESULTS: In all, 60 children met the inclusion criteria (mean age 12.6 ± 4.6 years,), 25 (42%) with mild disease, 17 (28%) moderate disease, and 18 (30%) severe disease. Twenty-seven (45%) had small bowel disease only. Median FC levels did not differ between children with small bowel only (2198 µg/g interquartile range [IQR] 696-2400) and those with colonic involvement (with or without small bowel disease; 2400 µg/g (IQR 475-2400) (P = 0.76). FC was elevated in 95% of patients, in comparison to CRP (86%) and erythrocyte sedimentation rate (ESR) (83%). Three children (5%) who had normal calprotectin levels also had low or normal CRP and/or ESR. There was no correlation between calprotectin levels and either the pediatric CD activity index (r = -0.11; P = 0.94) or physicians global assessment. CONCLUSIONS: FC levels in active disease confined to the small bowel were elevated in the vast majority of children and site of disease was not a confounding factor in this setting. Patients with low FC had a trend toward low levels of inflammatory markers as well. We did not find a significant correlation between FC and clinical indices of activity.

Characterization of adherent-invasive Escherichia coli isolated from pediatric patients with inflammatory bowel disease.

BACKGROUND: Crohn's disease (CD) and ulcerative colitis (UC), known as inflammatory bowel diseases (IBD), are characterized by an abnormal immunological response to commensal bacteria colonizing intestinal lumen and mucosa. Among the latter, strains of adherent-invasive Escherichia coli (AIEC), capable of adhering to and invading epithelium, and to replicate in macrophages, have been described in CD adults. We aimed at identifying and characterizing AIEC strains in pediatric IBD. METHODS: In all, 24 CD children, 10 UC, and 23 controls were investigated. Mucosal biopsies, taken during colonoscopy, were analyzed for the presence of AIEC strains by an adhesive-invasive test. Protein expression of the specific AIEC receptor, the carcinoembryonic antigen-related cell adhesion molecule 6 (CEACAM6), was evaluated by western blot and immunohistochemistry, while tumor necrosis factor alpha (TNF-α) and interleukin (IL)-8 mRNA expression was detected by real-time polymerase chain reaction (PCR), after bacterial infection. Transmission electron microscopy and trans-epithelial electric resistance assays were performed on biopsies to assess bacteria-induced morphological and functional epithelial alterations. RESULTS: Two bacterial strains, EC15 and EC10, were found to adhere and invade the Caco2 cell line, similar to the well-known AIEC strain LF82 (positive control): they upregulated CEACAM6, TNF-α, and IL-8 gene/protein expression, in vitro and in cultured intestinal mucosa; they could also survive inside macrophages and damage the epithelial barrier integrity. Lesions in the inflamed tissues were associated with bacterial infection. CONCLUSIONS: This is the first study showing the presence of adhesive-invasive bacteria strains in the inflamed tissues of children with IBD. Collective features of these strains indicate that they belong to the AIEC spectrum, suggesting their possible role in disease pathogenesis.

Lymphoma risk in children and young adults with inflammatory bowel disease: analysis of a large single-center cohort.

BACKGROUND: Prior studies suggest an increased risk of lymphoma in adults with inflammatory bowel disease (IBD). Cases of lymphoma have also been reported in children with IBD. However, the precise risk of lymphoma in relation to drug exposure has not been ascertained in children. METHODS: We conducted a single-center, retrospective study of 1560 children and young adults with IBD evaluated at Children's Hospital Boston between 1979 and 2008. Of this group, 186 patients were excluded due to incorrect diagnosis, one-time second-opinion visits, or missing hospital records. The remaining 1374 patients had charts reviewed to determine whether lymphoma developed while they were receiving their clinical care at our institution and the duration of exposure to various IBD medications. The rate of lymphoma was calculated in patient-years of exposure for each class of medications utilized in IBD. RESULTS: Of 1374 patients (741 male; age at diagnosis 12.1 ± 4.0 years; 791 Crohn's disease [CD], 535 ulcerative colitis [UC], 48 IBD unclassified), we identified two patients who developed lymphoma (one Hodgkin, one anaplastic large cell), in 6624 patient-years of follow-up (mean duration follow-up 4.8 years per patient). Both patients were males (ages 12 and 18 years at time of lymphoma onset) and were receiving thiopurines but had not yet received biologics at the time of their cancer diagnosis. They were both treated with chemotherapy and are alive without cancer 32+ and 76+ months since diagnosis. The absolute incidence rate of lymphoma for patients having received thiopurines was 4.5 per 10,000 patient-years compared to the expected rate of 0.58 per 10,000 patient-years, with a standardized incidence ratio (SIR) of 7.51 (95% confidence interval [CI] 0.74-41.98). CONCLUSIONS: The overall risk of lymphoma in children with IBD is low, with only two cases seen in our hospital over a 30-year period. The lymphoma risk (as estimated by SIR) in children receiving thiopurines is comparable to that reported in studies of adults. While there may be an increased risk of lymphoma in children treated with thiopurines, the risk did not reach statistical significance in this large cohort.