Evaluation of Risk for Thromboembolic Events in Pediatric Inflammatory Bowel Disease.

OBJECTIVES: The occurrence of thrombotic events in adult patients with inflammatory bowel disease (IBD) is linked to multiple interactions between hereditary and acquired risk factors. There are few published data concerning children with iBD. The aim of this study was to investigate the presence of thromboembolic risk factors also in children with iBD. METHODS: We enrolled three groups of children: one with Crohn disease (cD), one with ulcerative colitis (Uc), and a control group of healthy subjects. For all the participants the potential thromboembolic risk was evaluated clinically and with laboratory tests. RESULTS: We studied: 30 children (25.6%) with CD, 28 (23.9%) with UC, and 59 (50.4%) healthy control subjects. Regarding Pediatric Crohn Disease Activity Index, no significant differences between thromboembolic risk factors and disease activity were detected. Instead, in the patients with UC, stratified with the Pediatric Ulcerative Colitis Activity Index, there was a statistically significant difference in serum fibrinogen levels between patients with mild and moderate/severe disease [3.8 (3.2-4.5) g/L vs 5.7 (4.8-6.2) g/L, P  < 0.0032]. serum homocysteine levels were lower in healthy controls than in CD (P = 0.176) and UC (P = 0.026). An increased level ofhomocysteine in UC with a homozygous mutation in the methylene tetrahydrofolate reductase C677T gene was also observed. CONCLUSIONS: Our study showed that children with IBD have clinical features, acquired and congenital factors that can increase thrombotic risk, similarly to adults.

Paradoxical Psoriasis Induced by Anti-TNFα Treatment: Evaluation of Disease-Specific Clinical and Genetic Markers.

Paradoxical psoriasis (PP) may occur during treatment with anti-tumor necrosis factor-alpha (TNF-α) drugs in various chronic immune-mediated diseases, mainly inflammatory bowel diseases (IBD) and psoriasis. In this study, clinical and genetic characteristics of PP arising in IBD and psoriatic patients were investigated to identify disease-specific markers of the paradoxical effect. A total of 161 IBD and psoriatic patients treated with anti-TNF-α drugs were included in the study. Of these patients, 39 developed PP. All patients were characterized for the main clinical-pathologic characteristics and genotyped for six candidate single nucleotide polymorphisms (SNPs) selected for their possible role in PP susceptibility. In IBD patients, the onset of PP was associated with female sex, presence of comorbidities, and use of adalimumab. IBD patients with PP had a higher frequency of the TNF-α rs1799964 rare allele (p = 0.006) compared with cases without the paradoxical effect, and a lower frequency of the human leucocyte antigen (HLA)-Cw06 rs10484554 rare allele (p = 0.03) compared with psoriatic patients with PP. Overall, these findings point to specific clinical and genetic characteristics of IBD patients with PP and provide data showing that genetic variability may be related to the paradoxical effect of anti-TNF-α drugs with possible implications into clinical practice.

A Treat to Target Strategy Using Panenteric Capsule Endoscopy in Pediatric Patients With Crohn's Disease.

BACKGROUND & AIMS: Pan-enteric capsule endoscopy (PCE) is effective for assessment of small intestinal and colonic Crohn's disease (CD) in pediatric patients. We aimed to determine whether PCE can be used to monitor mucosal healing and deep remission, in a treat to target strategy for pediatric patients with CD. METHODS: We performed a prospective study of 48 children with a diagnosis of CD at a tertiary care pediatric gastroenterology unit; 46 patients were included in the final analysis. Biomarker, imaging, and PCE analyses were performed at baseline and after 24 and 52 weeks. Small bowel and colonic mucosal healing were defined by Lewis scores <135 and simple endoscopic score for CD ≤1, respectively. Clinical remission was defined as defined as a pediatric CD activity index score <10 and biomarker-based remission based on normal levels of biomarkers; deep remission was defined as a combination of clinical remission, biomarker-based remission, and mucosal healing. Treatments were adjusted based on findings from PCE (imaging was considered only for patients with negative findings from PCE). Therapies were introduced, optimized, switched, or combined at the discretion of treating clinicians. The primary outcome was the ability of PCE to assess mucosal healing and deep remission at 3 timepoints and to guide a treat to target strategy. RESULTS: PCE detected inflammation in 34 patients (71%) at baseline, 22 patients (46%) at week 24, and 18 patients (39%) at week 52 (P for comparison among timepoints <.05). Findings from PCE led to a change in therapy for 34 patients (71%) at baseline and 11 patients (23%) at 24 weeks, whereas only 2 patients with negative results from PCE (4%) changed therapies based on findings from imaging. When the treat to target strategy was applied, proportions of patients with mucosal healing and deep remission increased from 21% at baseline, to 54% at week 24, to 58% at week 52 (P for comparison among timepoints <.05); 2 patients (4%) did not respond to treatment. CONCLUSION: In a prospective study of 48 children with CD, we found a treat to target strategy, based on findings from PCE, to significantly increase the proportions of patients with mucosal healing and deep remission. CLINICAL TRIAL: gov no: NCT03161886.

MRI reveals different Crohn's disease phenotypes in children and adults.

OBJECTIVES: To identify differences between two cohorts of adult and pediatric patients affected by Crohn's disease (CD), with regard to lesion location in the small intestine and colon-rectum, lesion activity, and prevalence of perianal disease (PD), using MRI as the main diagnostic tool. METHODS: We retrospectively reviewed 350 consecutive MRI examinations performed between 2013 and 2016 in outpatients or inpatients with histologically proven CD, monitored by the Gastroenterology and Pediatric Units of our Hospital. The magnetic resonance enterography (MRE) protocol for adult and pediatric CD patients routinely includes evaluation of nine different intestinal segments (from jejunum to rectum) and of the anal canal. Intestinal activity was also calculated using a validated score. Perianal disease (PD) was staged. Fisher's exact test was used and the odds ratio (OR) was calculated. RESULTS: Two hundred and nineteen out of 350 MRI studies (118 adults and 101 children) were included. The prevalence of PD was 34.6% in children and 16.1% in adults (OR = 2.8; p = 0.0017). Pediatric patients showed more frequent rectal involvement (29.7% vs 13.5%, OR = 2.7; p = 0.0045) and higher risk of PD in the presence of rectal disease (p = 0.043; OR = 4.5). In pediatric patients with severe colorectal disease, the prevalence of PD was twofold (86.7% vs 40%; p = 0.072). Using the clinical Montreal classification for lesion location, no significant differences emerged between the two patient populations. CONCLUSIONS: MRI showed a significantly higher prevalence of rectal involvement and perianal disease in the pediatric population. These results may have a relevant clinical impact and deserve further investigation. KEY POINTS: • To our knowledge, this is the largest morphological comparative study available in the literature using MRI as the main diagnostic tool to compare adult patients and children with Crohn's disease. • Our study showed significant differences between adults and children: a higher prevalence of rectal and perianal fistulous disease (PD) in pediatric patients and an increased prevalence of PD in the presence of severe colon-rectum involvement. • The association of rectal and perianal disease implies a poorer clinical prognosis and a higher risk of disabling complications in pediatric patients.

Predictors of Long-term Clinical and Endoscopic Remission in Children With Crohn Disease Treated With Infliximab.

OBJECTIVES: We aimed to identify early noninvasive predictors of clinical and endoscopic remission in children with Crohn disease (CD) under infliximab (IFX). METHODS: Prospective observational study conducted in children with moderate-to-severe CD starting IFX. All patients underwent weighted pediatric CD activity index (wPCDAI) assessment, C-reactive protein and fecal calprotectin (FC) at week 0, 14, and 48. Endoscopy was performed at 0 and 48 weeks. The primary outcome was to determine the ability of 14-week wPCDAI, C-reactive protein, and FC to predict 1-year steroid-free clinical remission and mucosal healing. As a secondary outcome we evaluated their concordance with Simple Endoscopic Score for CD (SES-CD) at week 48. RESULTS: Forty-one children were enrolled. At 1 year, 21 (51%) and 16 (39%) were in clinical and endoscopic remission. Only combined postinduction FC and wPCDAI were able to predict 1-year clinical and endoscopic remission (hazard ratio 4.81 [95% confidence interval 1.76-20.45], P = 0.05 and hazard ratio 5.51 [95% confidence interval 1.83-26.9], P = 0.03). One-year SES-CD moderately correlated with FC (r = 0.52; P = 0.001). The FC cut-off value for mucosal healing was 120.5 µg/g (area under the curve 0.863, 83% sensitivity, 75.5% specificity; P = 0.005). The concordance between wPCDAI and SES-CD was excellent and good for severe disease and remission (k 0.87 and 0.76). CONCLUSIONS: Post induction FC combined with wPCDAI can predict 1-year clinical and endoscopic response to IFX in pediatric CD. FC shows a moderate correlation with SES-CD, whereas wPCDAI has a good concordance with endoscopic remission or severe disease, but not with mild and moderate disease.

A promising medium-term follow-up of pediatric sclerosing cholangitis: Mild phenotype or early diagnosis?

AIM: Sclerosing cholangitis (SC) is a chronic cholestatic liver disease that is being increasingly diagnosed in childhood. The long-term course and prognosis of pediatric SC are poorly described. METHODS: We reviewed data of pediatric SC patients, followed in two referral centers, during a period of up to 20 years. We aimed to evaluate long-term outcomes according to SC phenotype. RESULTS: Among 45 patients (median age, 10.4 years; male patients, 73.4%) 29 (64.4%) were asymptomatic at presentation. Twenty patients (44%) had a concomitant inflammatory bowel disease (SC/IBD). Autoimmune features were found in 20 patients (44%). Liver biopsy showed severe fibrosis or cirrhosis in 32% of cases. Patients with SC alone had a higher rate of interface hepatitis at liver biopsy than SC/IBD patients. All children received ursodeoxycholic acid at diagnosis, and 17 received steroids and/or azathioprine. After a mean follow-up of 8.7 ± 5.6 years, all patients were alive and seven developed at least one liver-related complication. At the end of follow-up, 10 patients stopped immunosuppressants and two had no therapy. Only two patients underwent liver transplantation. Complication-free survival did not differ between SC/IBD and SC patients, but survival was longer in patients without autoimmune features. CONCLUSIONS: In our early diagnosed cohort, the 9-year survival with native liver was better than that reported in other studies. Approximately 15% of patients developed liver-related disease complications, less than previously reported. The long-term course of SC was negatively influenced by the presence of autoimmune features, but not by concomitant IBD.

Magnetic resonance enterography, small-intestine contrast US, and capsule endoscopy to evaluate the small bowel in pediatric Crohn's disease: a prospective, blinded, comparison study.

BACKGROUND: Small-bowel (SB) disease is a severe clinical entity among the phenotypes of Crohn's disease (CD). OBJECTIVE: To assess sensitivity, specificity, and accuracy of magnetic resonance enterography (MRE), small-intestine contrast US (SICUS), and capsule endoscopy (CE) in the diagnosis of pediatric SB-CD. DESIGN: Prospective, blinded, comparison study. SETTING: Tertiary center for pediatric inflammatory bowel disease. PATIENTS: Children with known or suspected CD. Diagnosis of SB obstruction at SICUS or MRE excluded patients from the study. INTERVENTION: Patients underwent ileocolonoscopy, MRE, SICUS, and CE over a 7-day period. For the imaging evaluation, SB was divided into 3 segments: jejunum, proximal and mid ileum, and terminal ileum. MAIN OUTCOME MEASUREMENTS: The performance of each method was compared to a consensus reference standard for upper SB and to ileocolonoscopy for the terminal ileum. RESULTS: Twenty-five patients completed the study. In the jejunum, the sensitivity of SICUS and CE was 92%, which was not significantly higher than MRE (75%); the specificity of CE (61%) was significantly lower than that of MRE (P = .04). In the proximal and mid ileum, MRE and CE did not have significantly higher sensitivity (100%) than SICUS (80%), but CE was less specific (P > .05). At the terminal ileum, SICUS and MRE were slightly more sensitive than CE (94% vs. 81%); however, the latter was more specific. LIMITATIONS: Use of the consensus reference standard for upper SB. Small number of patients. CONCLUSION: SICUS, MRE, and CE are all effective options for imaging SB. An integrated use of different tools should be suggested to achieve a complete assessment of the SB in children with suspected or confirmed CD.

Aortic Intima-Media Thickness as an Early Marker of Atherosclerosis in Children With Inflammatory Bowel Disease.

OBJECTIVES: The aims of this study were to determine the presence of endothelial dysfunction by measuring aortic intima-media thickness (aIMT) and carotid intima-media thickness (cIMT) and to evaluate the role of traditional risk factors for premature atherosclerosis in children with inflammatory bowel disease (IBD). METHODS: Thirty-four children with IBD (25 Crohn disease [CD] and 9 ulcerative colitis [UC]; mean age 11.1 years) and 27 healthy subjects matched for sex and age were enrolled. In all of the patients, demographic characteristics and risk factors for atherosclerosis (age, sex, body mass index, blood pressure, dyslipidemia, active and passive smoking, and family history for cardiovascular diseases), CD and UC clinical activity scores, and inflammatory markers were evaluated. aIMT and cIMT were measured by high-resolution B-mode ultrasound. RESULTS: aIMT was significantly higher in patients than in controls (P < 0.0005). No significant differences were found for cIMT, although the carotid thickness was higher in patients with IBD than in healthy subjects. At a univariate analysis, inflammatory markers levels and tobacco smoking exposure were significantly related to higher aIMT values, whereas in a multivariate regression model, the inflammatory status was the only independent variable correlated with high aIMT. CONCLUSIONS: aIMT is an earlier marker of preclinical atherosclerosis than cIMT in young children with active IBD. The inflammatory status and the smoking exposure are significantly correlated with the premature endothelial dysfunction. These data emphasize the importance of controlling the chronic intestinal inflammation and endorsing smoke-free environments for children and adolescents with IBD.

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.

Detection of Crohn disease lesions of the small and large bowel in pediatric patients: diagnostic value of MR enterography versus reference examinations.

OBJECTIVE: The purpose of this article is to prospectively determine the accuracy of MR enterography in detecting Crohn disease lesions from the jejunum to the anorectal region in pediatric patients, in comparison with main reference investigations. SUBJECTS AND METHODS: Fifty consecutive children with known Crohn disease underwent MR enterography with oral contrast agent and gadolinium-chelate intravenous injection. Two radiologists detected and localized lesions by dividing the bowel into nine segments (450 analyzed segments in 50 patients). Ileocolonoscopy, barium studies, intestinal ultrasound, and capsule endoscopy were considered as first- and second-level reference examinations and were performed within 15 days of MR enterography. RESULTS: MR enterography detected lesions in 164 of 450 segments, with 155 true-positive and nine false-positive findings; overall sensitivity, specificity, and positive and negative predictive values for small- and large-bowel lesions were 94.5%, 97%, 94.5%, and 97%, respectively (ĸ = 0.93; 95% CI, 0.89-0.97). Sensitivity and specificity values were 88% and 97%, respectively, for the jejunum, 100% and 97% for the proximal-to-mid ileum, 100% and 100% for the distal ileum, 93% and 100% for the cecum, 70% and 97% for the ascending colon, 80% and 100% for the transverse colon, 100% and 92% for the descending colon, 96% and 90% for the sigmoid colon, and 96% and 88% for the rectum. From jejunum to rectum, the AUC value ranged between 0.916 (jejunum) and 1.00 (distal ileum). Perianal fistulas were diagnosed in 15 patients, and other complications were found in 13 patients. CONCLUSION: MR enterography showed an accuracy comparable to that of reference investigations, for both small- and large-bowel lesions. Because MR enterography is safer and more comprehensive than the reference examinations, it should be considered the primary examination for detecting Crohn disease lesions in children.

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.

Small intestine contrast ultrasonography in pediatric Crohn's disease.

OBJECTIVE: To evaluate the diagnostic accuracy of small intestine contrast ultrasonography (SICUS) in pediatric Crohn's disease (CD). STUDY DESIGN: A total of 51 consecutive patients (median age 15 years; range 3-20, 31 male patients), 21 with suspected and 30 with proven CD, were studied. All patients underwent standard ultrasonography (ie, transabdominal ultrasonography [TUS]), SICUS, small bowel follow-through, and upper and lower endoscopy. SICUS was performed in patients after they ingested an oral contrast solution. TUS and SICUS were compared with small bowel follow-through and endoscopy via use of the final diagnosis as reference standard. RESULTS: In undiagnosed patients, the sensitivity and specificity of TUS and SICUS in detecting CD small bowel lesions were 75% and 100% and 100% and 100%, respectively. In patients with proven CD, the sensitivity and specificity of TUS and SICUS were 76% and 100% and 96% and 100%, respectively. The agreement (k) with radiology for site of lesions was almost perfect for SICUS (0.93), both for jejunal and ileal lesions, and it was fair (0.40) for jejunal and substantial (0.68) for ileal lesions for TUS. Compared with radiology SICUS correctly assessed the length of lesions, whereas TUS underestimated it (P = .0001). CONCLUSIONS: The radiation-free technique SICUS is comparable with radiology and more accurate than TUS in assessing small bowel lesions in pediatric CD, mainly in the detection of proximal small bowel disease.

Management of collagenous gastritis in children: Case series and literature review.

Collagenous gastritis (CG) is a rare histopathological finding on gastric biopsies in children. It is associated with abdominal pain and iron deficiency anemia, usually not respondent to oral iron supplements. The aim of this study was to describe our experience in the management of pediatric patients with CG. Moreover, we propose to review the literature on this topic. We retrospectively reviewed all pediatric patients diagnosed with CG at our centre from January 2014 to January 2019. Three pediatric patients (2 F, mean age 12.3) were diagnosed with CG during the study period. Two presented with moderate and one with severe anemia. Symptoms were abdominal pain, asthenia and headache in two and asthenia and abdominal pain in one. All underwent upper and lower gastrointestinal endoscopy. All were firstly started with oral iron supplements with no benefit, principally due to poor compliance secondary to the worsening of the epigastric pain and proton pump inhibitor resistance. Therefore, they underwent ferric carboxymaltose (FCM) infusion with good clinical and laboratory response. Patients received a mean of two infusions/year, with stable hemoglobin levels and no adverse outcomes. Our review failed to identify a consistent response to specific treatments. Considering the apparent benign nature of the disease, symptomatic and supportive treatments are advisable. Iron deficiency anemia is largely present and therapy with oral iron supplements is not always successful. In our study, FCM infusion was effective in increasing the key blood indices in patients who poorly tolerated oral supplements.

Premature subclinical atherosclerosis in pediatric inflammatory bowel disease.

OBJECTIVES: To investigate the risk for developing an early endothelial dysfunction based on increased intima media thickness (IMT) and reduced flow-mediated dilation (FMD) in children with inflammatory bowel disease (IBD), and to evaluate the role of traditional and nontraditional risk factors in determining premature atherosclerosis. STUDY DESIGN: We studied 27 patients with Crohn's disease (CD) and 25 patients with ulcerative colitis (UC) (mean age, 15.2 years; mean duration of disease, 48.05 months); 31 subjects served as controls. Demographic data (age, sex, family history of diabetes, cardiovascular disease, hypertension, hypercholesterolemia), traditional risk factors for atherosclerosis (blood pressure, body mass index, active and passive smoking, dyslipidemia), and UC and CD activity indexes (Pediatric Ulcerative Colitis Activity Index and Pediatric Crohn's Disease Activity Index, respectively) were collected. The IMT of the carotid arteries was measured by high-resolution B-mode ultrasound, and endothelial function was evaluated by FMD in the brachial artery in response to reactive hyperemia. RESULTS: Compared with controls, patients with CD had significantly greater exposure to passive smoking and had lower body mass index and high-density lipoprotein cholesterol values. IMT was significantly higher in patients than controls (P < .0001), and the percentage of FMD was significantly lower in both patients with CD (P < .0001) and patients with UC (P < .01) versus controls. In multivariate analysis, diagnosis of IBD was an independent risk factor for atherosclerosis. CONCLUSION: Premature endothelial dysfunction occurs in pediatric IBD. This represents a new challenge in the management of pediatric IBD, leading to prevention strategies of cardiovascular disease.

Differences in the location and activity of intestinal Crohn's disease lesions between adult and paediatric patients detected with MRI.

OBJECTIVES: To prospectively compare paediatric patients (PP) and adult patients (AP) affected by Crohn's disease (CD) in terms of the location and activity of intestinal lesions. METHODS: Forty-three children (mean age 15 years) and 43 adults (mean age 48 years) with proven CD underwent magnetic resonance enterography (MRE) to localise lesions and detect their activity in 9 segments of the small and large bowel. The results were analysed on a per patient and per segment basis. Ileo-colonoscopy was performed in all patients. P values less than 0.05 were considered statistically significant. RESULTS: Involvement of terminal ileum was significantly different in the two groups: observed in 100 % of AP (43/43) versus 58 % (23/43) of PP (P < 0.0001). Conversely, the colon was diseased in 84 % of PP versus 64 % of AP. In particular, left colonic segments were significantly more involved in PP (descending colon 53 % versus 21 %, P < 0.01; rectum 67 % versus 23 %, P < 0.0001; sigmoid colon 56 % versus 37 %, not significant), whereas caecal involvement was equal in both groups. In children the maximal disease activity was found in left colonic segments, whereas in adults it was in the terminal ileum. CONCLUSIONS: MRE detected significant differences between the two populations, showing a more extensive and severe involvement of the left colon in children but the distal ileum in adults. KEY POINTS : • MRI is useful for assessing Crohn's disease in adult and paediatric patients. • Adult and paediatric patients show different intestinal involvement on MRI. • The distal ileum is maximally involved in adults vs. the left colon in children. • The causes of the severe left colonic disease in children are unknown. • The extensive colonic involvement in children has clinical-diagnostic implications.

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.

Peripheral and intestinal CD4+ T cells with a regulatory phenotype in pediatric patients with inflammatory bowel disease.

OBJECTIVES: Regulatory T cells (TR cells) play a crucial role in the regulation of intestinal inflammation. To examine the pathogenetic relevance of TR cells in inflammatory bowel disease (IBD), we evaluated their frequency in peripheral blood and inflamed and noninflamed mucosae of pediatric patients with IBD and age-matched controls without IBD; we also characterized the immune profile of the inflammatory infiltrate in the different phases of the disease. PATIENTS AND METHODS: Circulating TR cells were investigated on peripheral blood mononuclear cells by fluorescence-activated cell sorting analysis; mucosal TR cells and inflammatory cell populations were investigated by immunohistochemistry on bioptic specimens. FOXP3 messenger RNA expression levels were confirmed using real-time polymerase chain reaction. RESULTS: FOXP3+ TR cells were significantly increased in the intestinal lesions of patients with active IBD, and returned to normal levels in posttherapy remission phase. At variance, circulating TR cell frequency was elevated in patients with IBD independently of disease activity, as it persisted in the remission phase. A selective imbalance in the frequency of CD4+ T and natural killer cell subsets characterized the abundant inflammatory infiltrate of active intestinal lesions, and also persisted, at a lower level, in noninflamed mucosae of patients in the remission phase. CONCLUSIONS: TR cell frequency is differently regulated in mucosal tissues and at the systemic level during the distinct phases of pediatric IBD. The inactive stage of pediatric IBD is characterized by an incomplete normalization of the immune profile, independently of the clinical efficacy of the therapy. The pediatric, early-onset condition may represent a privileged observatory to dissect the immune-mediated pathogenetic mechanisms at the basis of the disease.

Efficacy of adalimumab in moderate-to-severe pediatric Crohn's disease.

OBJECTIVES: The use of tumor necrosis factor-alpha (TNF-alpha) antagonists has changed the therapeutic strategy for Crohn's disease (CD). Adalimumab (ADA), a fully human anti-TNF-alpha monoclonal antibody, is an effective therapy for patients with CD, both naive patients and those intolerant or refractory to Infliximab (IFX), a chimeric anti-TNF-alpha agent. However, the use of ADA is rarely reported in pediatric CD. We performed an open prospective evaluation of short- and long-term efficacy and safety of ADA in children with moderate-to-severe CD. METHODS: A total of 23 pediatric CD patients (9 naive and 14 intolerant or unresponsive to IFX) received ADA subcutaneously as a loading schedule at weeks 0 and 2, and at every other week (eow) during a 48-week maintenance phase. Loading and maintenance doses were 160/80 and 80 mg eow in 13 cases, 120/80 and 80 mg eow in 2, and 80/40 and 40 mg eow in 8 cases. The primary efficacy outcomes were clinical remission and response at different scheduled visits along the maintenance phase. At baseline, 13 patients also received immunomodulators (IMs). RESULTS: At weeks 2, 4, 12, 24, and 48, remission rates were 36.3, 60.8, 30.5, 50, and 65.2%, respectively, whereas response rates were 87, 88, 70, 86, and 91%, respectively. Four patients at week 24 and 2 at week 48 received IMs; the mean daily corticosteroid dose, disease activity index, C-reactive protein level, and erythrocyte sedimentation rate decreased significantly throughout the trial. No serious adverse events were recorded. CONCLUSIONS: ADA can be an effective and safe biological agent for inducing and maintaining remission in children with moderate-to-severe CD, even in those with previous IFX therapy.

Oxidosqualene cyclase from Saccharomyces cerevisiae, Trypanosoma cruzi, Pneumocystis carinii and Arabidopsis thaliana expressed in yeast: a model for the development of novel antiparasitic agents.

A series of 25 compounds, some of which previously were described as inhibitors of human liver microsomal oxidosqualene cyclase (OSC), were tested as inhibitors of Saccharomyces cerevisiae, Trypanosoma cruzi, Pneumocystis carinii and Arabidopsis thaliana OSCs expressed in an OSC-defective strain of S. cerevisiae. The screening identified three derivatives particularly promising for the development of novel anti-Trypanosoma agents and eight derivatives for the development of novel anti-Pneumocystis agents.

Umbelliferone aminoalkyl derivatives as inhibitors of human oxidosqualene-lanosterol cyclase.

Human and murine lanosterol synthases (EC 5.4.99.7) were studied as targets of a series of umbelliferone aminoalkyl derivatives previously tested as inhibitors of oxidosqualene cyclases from other eukaryotes. Tests were carried out on cell cultures of human keratinocytes and mouse 3T3 fibroblasts incubated with radiolabeled acetate, and on homogenates prepared from yeast cells expressing human lanosterol synthase, incubated with radiolabeled oxidosqualene. In cell cultures of both human keratinocytes and mouse 3T3 fibroblasts, the observed inhibition of cholesterol biosynthesis was selective for oxidosqualene cyclase. The most active compounds bear an allylmethylamino chain in position-7 of the coumarin ring. The inhibition was critically dependent on the position and length of the inhibitor side chain, as well as on the type of aminoalkyl group inserted at the end of the same chain. Molecular docking analyses, carried out to clarify details of inhibitors/enzyme interactions, proved useful to explain the observed differences in inhibitory activities.