Diagnostic Delay of Celiac Disease in Childhood.

Importance: The extent and factors associated with risk of diagnostic delay in pediatric celiac disease (CD) are poorly understood. Objectives: To investigate the diagnostic delay of CD in childhood, and to assess factors associated with this delay. Design, Setting, and Participants: Multicenter, retrospective, cross-sectional study (2010-2019) of pediatric (aged 0-18 years) patients with CD from 13 pediatric tertiary referral centers in Italy. Data were analyzed from January to June 2023. Main Outcomes and Measures: The overall diagnostic delay (ie, the time lapse occurring from the first symptoms or clinical data indicative of CD and the definitive diagnosis), further split into preconsultation and postconsultation diagnostic delay, were described. Univariable and multivariable linear regression models for factors associated with diagnostic delay were fitted. Factors associated with extreme diagnostic delay (ie, 1.5 × 75th percentile) and misdiagnosis were assessed. Results: A total of 3171 patients with CD were included. The mean (SD) age was 6.2 (3.9) years; 2010 patients (63.4%) were female; and 10 patients (0.3%) were Asian, 41 (1.3%) were Northern African, and 3115 (98.3%) were White. The median (IQR) overall diagnostic delay was 5 (2-11) months, and preconsultation and postconsultation diagnostic delay were 2 (0-6) months and 1 (0-3) month, respectively. The median (IQR) extreme overall diagnostic delay (586 cases [18.5%]) was 11 (5-131) months, and the preconsultation and postconsultation delays were 6 (2-120) and 3 (1-131) months, respectively. Patients who had a first diagnosis when aged less than 3 years (650 patients [20.5%]) showed a shorter diagnostic delay, both overall (median [IQR], 4 [1-7] months for patients aged less than 3 years vs 5 [2-12] months for others) and postconsultation (median [IQR], 1 [0-2] month for patients aged less than 3 years vs 2 [0-4] months for others). A shorter delay was registered in male patients, both overall (median [IQR], 4 [1-10] months for male patients vs 5 [2-12] months for female patients) and preconsultation (median [IQR], 1 [0-6] month for male patients vs 2 [0-6] months for female patients). Family history of CD was associated with lower preconsultation delay (odds ratio [OR], 0.59; 95% CI, 0.47-0.74) and lower overall extreme diagnostic delay (OR, 0.75; 95% CI, 0.56-0.99). Neurological symptoms (78 patients [21.5%]; OR, 1.35; 95% CI, 1.03-1.78), gastroesophageal reflux (9 patients [28.1%]; OR, 1.87; 95% CI, 1.02-3.42), and failure to thrive (215 patients [22.6%]; OR, 1.62; 95% CI, 1.31-2.00) showed a more frequent extreme diagnostic delay. A previous misdiagnosis (124 patients [4.0%]) was more frequently associated with gastroesophageal reflux disease, diarrhea, bloating, abdominal pain, constipation, fatigue, osteopenia, and villous atrophy (Marsh 3 classification). Conclusions and Relevance: In this cross-sectional study of pediatric CD, the diagnostic delay was rather short. Some factors associated with risk for longer diagnostic delay and misdiagnosis emerged, and these should be addressed in future studies.

Infliximab therapy decreases the expression of serum and faecal miR-126 and miR-20a in paediatric Crohn's disease: A pilot study.

AIM: We aimed to evaluate the serum and faecal expression of miR-126 and miR-20a in children with Crohn's disease (CD) during infliximab (IFX) therapy. METHODS: In this prospective observational study, serum and faeces from CD patients were collected before IFX therapy (T0), after induction (T1) and after 6 months from IFX (T2). IFX levels were determined by Enzyme-linked immunosorbent assay at T1 and T2. miRNAs were profiled through Real-Time RT-PCR. The activity of disease was evaluated through the Paediatric Crohn's disease activity index (PCDAI), serum C-reactive protein (CRP) and faecal calprotectin. RESULTS: Nine CD children were enrolled. Serum and faecal miR-126 and miR-20a levels were higher at T0 and showed a time-dependent decrease, being significantly down-regulated after IFX treatment at T2. Specifically, IFX levels recorded at T1 and T2 negatively correlated with the serum and faecal expression of miR-126 and miR-20a. Serum and faecal changes of miR-126 and miR20-a were positively associated with the decrease of the inflammatory marker CRP and PDCAI at all time points. CONCLUSION: In children with CD, IFX therapy decreases the expression of serum and faecal miR-126 and miR-20a, suggesting an involvement of these two miRNAs in the action of the drug.

Prevalence of functional gastrointestinal disorders in Italian children living in different regions: analysis of the difference and the role of diet.

BACKGROUND: Functional Gastrointestinal Disorders (FGIDs) are common in pediatric age. AIMS: To estimate the prevalence of FGIDs in Italian children and evaluate the impact of diet. METHODS: Healthy children aged 4-18 years were recruited in a multicenter cross-sectional study. We evaluated their eating habits and the presence of FGIDs, using Rome IV criteria, 3-day food diaries and Mediterranean Diet Quality Index (KIDMED) questionnaires. RESULTS: Seven hundred forty subjects were enrolled:369 children aged 4-9 years (Group A), and 371 adolescents 10-18 years old (Group B). The overall prevalence of FGIDs was 26.4% in Group A and 26.2% in Group B, with a significant higher prevalence in females in both groups. The most frequent disorders were functional constipation, functional dyspepsia, and abdominal migraine. No significant difference in FGIDs prevalence was found between Northern and Southern Italy, despite significant variation in diet. In Group A there was a significant difference in KIDMED between North and South (5.3 ± 1 vs 6 ± 1.2, respectively; p = 0.001). A significant association between FGIDs and KIDMED was found in Group A (OR=0.83, p = 0.034), but not in Group B (OR=0.89, p = 0.166). CONCLUSIONS: FGIDs are common in Italian children, with a higher prevalence in females. Despite significant differences in dietary habits between North and South, FGIDs prevalence does not vary significantly.

The Role of Gluten in Gastrointestinal Disorders: A Review.

Gluten is only partially digested by intestinal enzymes and can generate peptides that can alter intestinal permeability, facilitating bacterial translocation, thus affecting the immune system. Few studies addressed the role of diet with gluten in the development of intestinal inflammation and in other gastrointestinal disorders. The aim of this narrative review was to analyse the role of gluten in several gastrointestinal diseases so as to give a useful overview of its effectiveness in the prevention and management of these disorders.

The use of calgranulin-C (S100A12) and fecal zonulin as possible non-invasive markers in children with inflammatory bowel disease: a clinical study.

Calgranulin-C (S100A12) and zonulin are considered markers of intestinal inflammation. Our aim was to evaluate fecal S100A12 (f-S100A12) and fecal zonulin (f-zonulin) in children with inflammatory bowel disease (IBD), compared to fecal calprotectin (FC) and serum inflammatory markers. We enrolled children with a previous diagnosis of Crohn's disease (CD) and ulcerative colitis (UC). F-S100A12, f-zonulin, and FC were determined by enzyme-linked immunosorbent assay (ELISA). Endoscopic examination was considered in the patients who underwent ileocolonoscopy within 2 weeks from the enrollment. One hundred seventeen children, 39.3% with CD and 60.7% with UC were enrolled. In both CD and UC, there was a significant direct correlation between FC and f-S100A12 levels. In children with CD and UC, both FC and f-S100A12 correlated with markers of serum inflammation. We found difference in FC and f-S100A12 levels between patients in clinical relapse and remission (FC: mean 1027 ± 818 mcg/ml vs 580 ± 695 mcg/ml respectively, p = 0.028; f-S100A12: mean 66.4 ± 48.2 mcg/ml vs 42.7 ± 40 mcg/ml, respectively p = 0.02). Moreover, we found difference in FC between children with endoscopic inflammation and remission (mean 825 ± 779 mcg/ml vs 473.3 ± 492 mcg/ml, respectively p = 0.048), as well as for f-S100A12 (53 ± 43 mcg/ml vs mean 31 ± 33 mcg/ml vs, respectively p = 0.019). No significant results were found for f-zonulin. CONCLUSION: Our data suggest that f-S100A12 and FC are both useful non-invasive biomarkers in the management of pediatric IBD in follow up and in monitoring endoscopic and clinical relapse. WHAT IS KNOWN: • Fecal calprotectin (FC), fecal S100A12 (f- S100A12), and fecal zonulin represent potential noninvasive markers of gut inflammation. • Since S100A12 is predominantly expressed by granulocytes, high levels of f-S100A12 should be more specific for inflammation than FC. WHAT IS NEW: • FC and f-S100A12 were correlated to each other and despite the lack of correlation with disease location, they were associated with endoscopic inflammation and clinical relapse in children with IBD. • No significant correlations were found between f-zonulin and the inflammatory parameters.

Prevalence of functional gastrointestinal disorders in children with celiac disease on different types of gluten-free diets.

BACKGROUND: Functional gastrointestinal disorders (FGIDs) are common during the pediatric age. FGIDs are not related to biochemical or structural abnormalities. However, since they have a high prevalence, several studies have evaluated an overlap between FGIDs and organic diseases. Individuals with celiac disease (CD) have been shown to be at an increased risk for functional abdominal pain, even if they adhere well to a gluten-free diet (GFD). Little information is available for the pediatric age group. The aims of our study were to evaluate the prevalence of FGIDS in CD children 1 year after diagnosis and to compare the prevalence of FGIDs in CD children on a GFD with processed foods compared with those on a GFD with natural products. AIM: To assess the prevalence of FGIDs in children with CD after 1 year of follow-up and to compare the prevalence of FGIDs in children with CD on a GFD with processed foods and in children on a GFD with natural products. METHODS: We recruited pediatric patients aged 1-18 years with a new CD diagnosis. Participants were randomized to two groups: Group A on a GFD with processed foods (diet 1); and group B on a GFD with natural products (diet 2). Clinical monitoring, diet assessment and the questionnaire on pediatric gastrointestinal symptoms-Rome IV version were performed at diagnosis (T0) and after 12 mo of follow-up (T1). Dietary intake was assessed using a 3-d food diary record. Data from the diaries were evaluated using WinFood nutrient analysis software. We assessed the prevalence of FGIDs at T1 and the correlation with the type of GFD. RESULTS: We registered 104 CD children, with 55 patients in group A (53.0%) and 49 patients in group B (47.0%). Initially, 30 of the 55 (54.5%) CD children were symptomatic in group A, while 25 of 49 (51.0%) were symptomatic in group B. At T1, in spite of a low or negative serology for CD, FGIDs prevalence was 10/55 (18.0%) in group A and 8/49 (16.3%) in group B, with no statistically significant difference between the two groups (P = 0.780). At T1 the macro- and micronutrient intake was similar across the two groups with no significant differences in nutrient analysis. However, in both groups at T1 we found that a lower prevalence of FGIDs (P = 0.055) was associated with an inferior caloric (odds ratio = 0.99, 95% confidence interval: 0.99-1.00) and fat (odds ratio = 0.33, 95% confidence interval: 0.65-0.95) intake. CONCLUSION: Our results showed that CD children on a GFD have gastrointestinal symptoms with an elevated prevalence of FGIDs. Our study suggests that developing FGIDs may be linked to caloric intake and percentage of food fat, but it does not change between a GFD with processed foods or a GFD with natural products. However, long-term monitoring is required to evaluate a correlation between FGIDs and various types of GFDs.

Role of Vitamin D in Celiac Disease and Inflammatory Bowel Diseases.

Vitamin D (VD) is a pro-hormone that has long been known as a key regulator of calcium homeostasis and bone health in both children and adults. In recent years, studies have shown that VD may exert many extra-skeletal functions, mainly through a relevant modulation of the innate and adaptive immune system. This has suggested that VD could play a fundamental role in conditioning development, clinical course, and treatment of several autoimmune disorders, including celiac disease (CD) and inflammatory bowel diseases (IBDs). The main aim of this review is to evaluate the relationships between VD, CD, and IBDs. Literature analysis showed a potential impact of VD on CD and IBDs can be reasonably assumed based on the well-documented in vitro and in vivo VD activities on the gastrointestinal tract and the immune system. The evidence that VD can preserve intestinal mucosa from chemical and immunological damage and that VD modulation of the immune system functions can contrast the mechanisms that lead to the intestinal modifications characteristic of gastrointestinal autoimmune diseases has suggested that VD could play a role in controlling both the development and the course of CD and IBDs. Administration of VD in already diagnosed CD and IBD cases has not always significantly modified disease course. However, despite these relevant problems, most of the experts recommend monitoring of VD levels in patients with CD and IBDs and administration of supplements in patients with hypovitaminosis.

Diet and Pediatric Functional Gastrointestinal Disorders in Mediterranean Countries.

Background: The increased intake of FODMAP (fermentable oligosaccharides, disaccharides, monosaccharides, and polyol) rich foods has been suggested as a possible trigger of functional gastrointestinal disorders (FGIDs). Despite the high FODMAP content, the Mediterranean diet (MD) appears to have beneficial effects on health. Our aim was to evaluate whether the prevalence of FGIDs in different Mediterranean countries may be influenced by FODMAP consumption and adherence to the MD. Methods: A school-based, cross-sectional, multicenter study was performed in six countries in the Mediterranean area: Croatia, Greece, Israel, Italy, Macedonia, and Serbia. Subjects 4-18 years were examined in relation to their eating habits and the presence of FGIDs, using Rome IV criteria, 3-day food diaries and Mediterranean Diet Quality Index in Children and Adolescents (KIDMED) questionnaires. Results: We enrolled 1972 subjects between 4 and 9 years old (Group A), and 2450 subjects between 10 and 18 years old (Group B). The overall prevalence of FGIDs was 16% in Group A and 26% in Group B. FODMAP intake was significantly different among countries for both age groups. In both groups, no significant association was found between FGIDs and FODMAPs. Adherence to the MD in all countries was intermediate, except for Serbia, where it was low. In both groups, we found a statistically significant association between FGIDs and the KIDMED score (Group A: OR = 0.83, p < 0.001; Group B: OR = 0.93, p = 0.005). Moreover, a significant association was found between the KIDMED score and functional constipation (Group A: OR = 0.89, p = 0.008; Group B: OR = 0.93, p = 0.010) and postprandial distress syndrome (Group A: OR = 0.86, p = 0.027; Group B: OR = 0.88, p = 0.004). Conclusions: Our data suggest that the prevalence of FGIDs in the Mediterranean area is not related to FODMAP consumption, whereas adherence to the MD seems to have a protective effect.

Effects of CB2 Receptor Modulation on Macrophage Polarization in Pediatric Celiac Disease.

Celiac Disease (CD) represents an autoimmune disorder triggered by the exposure to gluten in genetically susceptible individuals. Recent studies suggest the involvement of macrophages in CD pathogenesis. Macrophages are immune cells, present as pro-inflammatory classically activated macrophages (M1) or as anti-inflammatory alternatively activated macrophages (M2). The Cannabinoid Receptor 2 (CB2) has important anti-inflammatory and immunoregulatory properties. We previously demonstrated that a common CB2 functional variant, Q63R, causing CB2 reduced function, is associated with several inflammatory and autoimmune diseases The first aim of this study was to investigate the phenotype of macrophages isolated from peripheral blood of CD patients and CB2 expression. The second aim was to evaluate the effects of CB2 pharmacological modulation on CD macrophage polarization. Moreover, by an in vitro model of "immunocompetent gut" we investigated the role of CD macrophages in inducing intestinal barrier damage and the possibility to restore its functionality modulating their polarization. We found an increased expression of M1 macrophages and a CB2 reduced expression. We also demonstrated CD M1 macrophages in inducing the typical mucosal barrier damage of CD. CB2 stimulation switches macrophage polarization towards the anti-inflammatory M2 phenotype thus reducing inflammation but also limiting the epithelial dysfunction. Therefore, we suggest CB2 receptor as a possible novel therapeutic target for CD by regulating macrophages polarization and by preventing mucosal barrier damage.

Functional Gastrointestinal Disorders in Mediterranean Countries According to Rome IV Criteria.

OBJECTIVES: The aim of this study was to assess the prevalence of functional gastrointestinal disorders (FGIDs) in children of Mediterranean area using Rome IV criteria and to compare the prevalence of FGIDs using Rome IV and Rome III criteria. METHODS: This was a cross-sectional study enrolling children and adolescents living in Croatia, Greece, Israel, Italy, Macedonia, and Serbia. Subjects were examined in relation to the presence of FGIDs, using the Rome IV criteria. Data were compared with the results of a previous study using Rome III data. RESULTS: We analyzed 1972 children ages 4 to 9 years (group A), and 2450 adolescents 10 to 18 years old (group B). The overall prevalence of FGIDs was 16% in group A and 26% in group B, with statistical differences among countries in both groups (P < 0.001). In group A, the prevalence of FGIDs and of functional constipation (FC) was significantly lower than in the previous study (P < 0.001), whereas in group B no significant difference was found. In both groups of age, the prevalence of abdominal migraine and irritable bowel syndrome decreased significantly (P < 0.001 and P < 0.001, respectively) using Rome IV versus Rome III criteria, conversely functional dyspepsia increased (P < 0.001). CONCLUSIONS: FGIDs are common in children and adolescents, their frequency increases with age, and there is a significant variation in the prevalence of some FGIDs among different European countries. The application of the Rome IV criteria resulted in a significantly lower prevalence of FGIDs in children compared with Rome III criteria.

The Mediterranean Diet in Paediatric Gastrointestinal Disorders.

The Mediterranean diet is considered one of the healthiest dietary patterns worldwide, thanks to a combination of foods rich mainly in antioxidants and anti-inflammatory nutrients. Many studies have demonstrated a strong relationship between the Mediterranean diet and some chronic gastrointestinal diseases. The aim of this narrative review was to analyse the role of the Mediterranean diet in several gastrointestinal diseases, so as to give a useful overview on its effectiveness in the prevention and management of these disorders.

Effectiveness of Mediterranean Diet's Adherence in children with Inflammatory Bowel Diseases.

BACKGROUND: Nutritional support is very important in the treatment of Paediatric Inflammatory Bowel Disease (IBD). The role of the Mediterranean Diet (MD) has been understudied in children with IBD. The aims of this study were to assess the dietary intakes of IBD children in comparison with healthy controls (HCs), their adherence to MD; and the relationship between inflammation and dietary behaviors. METHODS: Paediatric IBD patients in clinical remission and HCs were enrolled. The nutritional status and adherence to the Mediterranean Diet was evaluated through a 3-day food diary and the Mediterranean Diet Quality Index for Children and Adolescents (KIDMED). RESULTS: The analysis of food diaries showed a significantly higher kilocalorie intake in IBD patients compared to HCs (p = 0.012), an increase in carbohydrates (p = 0.015) and in protein intake (p = 0.024). Both IBD and HCs have an intermediate adherence to MD. The comparison between Crohn's disease (CD) and Ulcerative colitis (UC) patients showed significant difference in protein intake in CD patients (p = 0.047), as well as for vitamin D (p = 0.044) and iron intake (p = 0.023). Interestingly; in IBD patients we found a significant association between adherence to MD and a low level of fecal calprotectin (p = 0.027). CONCLUSION: Children with IBD in remission have a sub-optimal food intake compared to HCs. MD seems to correlate to decreased intestinal inflammation.

Exclusive enteral nutrition effect on the clinical course of pediatric Crohn's disease: a single center experience.

The aim of this study was to evaluate the short- and long-term outcomes of exclusive enteral nutrition (EEN) versus corticosteroids (CS) as induction therapy, in a cohort of pediatric patients with Crohn's disease (CD). A retrospective study of patients with CD has been conducted. Clinical characteristics, laboratory parameters, and pediatric Crohn's disease activity index (PCDAI) were evaluated at diagnosis and at different follow-up points. Subjects were divided in EEN-induction group, receiving EEN, and CS-induction group, treated with oral CS. We evaluated 47 patients in the EEN-induction group and 21 patients in the CS-induction group. After 8 weeks from diagnosis, we detected a significant improvement in CRP (p = 0.001) and albumin (p = 0.05), in EEN-induction group compared with the CS-induction group. PCDAI was significantly lower in the EEN-induction group versus the CS-induction group after 8 weeks (p = 0.04) and 1 year (p = 0.03) of follow-up. After 2 years from diagnosis, the number of subjects needing immunomodulators (IMM, azathioprine or methotrexate) was significantly higher in the CS-induction group compared with the EEN-induction group (p = 0.02).Conclusion: EEN has the same effectiveness of CS therapy in induction of remission but seems to have a more pronounced effect on disease activity. In our cohort, the need to use IMM seems to be reduced in subjects initially treated with EEN. What is Known: • Exclusive enteral nutrition (EEN) has the same effectiveness of corticosteroids (CS) in the induction of remission in pediatric Crohn's disease. • EEN offers numerous advantages over CS, in terms of improved nutrition and mucosal healing. What is New: • Induction of remission with EEN seems to have a more pronounced effect on disease activity compared to induction with CS. • In our cohort, induction of remission with EEN seems to reduce the need of therapy with immunomodulators at 2 years of follow-up.

The Role of Inflammation on Vitamin D Levels in a Cohort of Pediatric Patients With Inflammatory Bowel Disease.

OBJECTIVES: Existing studies usually do not measure the free vitamin D in pediatric patients with inflammatory bowel disease (IBD) and not consider the effect of inflammation on vitamin D levels. The aim of our study was to evaluate the concentrations of vitamin D-binding protein (VDBP), total and free 25-hydroxyvitamin-D (25(OH)D), and to correlate these values with the disease activity markers. METHODS: Newly diagnosed children with IBD and a group of healthy controls (HCs) were enrolled. VDBP and total and free 25(OH)D levels were measured by enzyme-linked immunosorbent assay and compared using the Student t test. In each patient with IBD, the activity scores of disease and the main inflammation markers were correlated to total and free 25(OH)D levels. C-reactive protein was also measured in the control group, and it was related to VDBP by a linear regression test for all the groups. RESULTS: Fifty-one consecutive children were enrolled: IBD = 33, HC = 18. Levels of total 25(OH)D were higher in HC than in patients with IBD (P = 0.01). The free/total 25(OH)D ratio was, however, higher in patients with IBD compared to HC (P < 0.001). Finally, levels of VDBP were lower in patients with IBD than in HC (P = 0.001). A significant direct correlation was found between the free/total 25(OH)D ratio and the activity index of disease (r: 0.17; P = 0.01). Moreover, in patients with IBD and controls we found a significant indirect correlation between VDBP and C-reactive protein (r: 0.12; P = 0.01). CONCLUSIONS: Inflammation inversely correlates to VDBP concentrations and patients with IBD, despite their deficiency in total 25(OH)D, have normal or even higher levels of free 25(OH)D.

Does Azathioprine induce endoscopic and histologic healing in pediatric inflammatory bowel disease? A prospective, observational study.

BACKGROUND: The new concept of disease remission for pediatric inflammatory bowel diseases (IBD) implies the achievement of mucosal healing. AIMS: We aimed to evaluate endoscopic and histologic healing in children with Ulcerative Colitis (UC) and Crohn's disease (CD) in clinical remission after 52 weeks of Azathioprine. METHODS: From December 2012 to July 2015 we prospectively enrolled IBD children starting Azathioprine. Enrolled patients in clinical remission underwent colonoscopy after 52 weeks. Macroscopic assessment was described with Mayo score and the simplified endoscopic score for UC and CD, respectively. For microscopic assessment, an average histology score was used. Data on inflammatory markers and fecal calprotectin were also collected. RESULTS: Fourty-seven patients were included in the analysis. Endoscopic healing was detected in 20/26 (76.9%) UC children and 10/21 (47.6%) CD patients. Median Mayo score and simplified endoscopic score were significantly decreased at week 52 (p<0.001; p=0.005). Median average histology score was not significantly different at week 52 in both diseases. Fecal calprotectin was directly correlated with simplified endoscopic score (T0: r=0.4, p=0.05; T52: r=0.5, p=0.01), but not with Mayo score. No correlation was found between endoscopic and histologic scores. CONCLUSIONS: IBD children under Azathioprine reach endoscopic healing, but not histological remission.

Cannabinoid Receptor 2 Functional Variant Contributes to the Risk for Pediatric Inflammatory Bowel Disease.

GOALS: We conducted a case-control association analysis to establish the role of a common CB2 functional variant, Q63R, in the susceptibility to inflammatory bowel disease (IBD). BACKGROUND: Endocannabinoids may limit intestinal inflammation through cannabinoid receptor 1 and/or 2 (CB1, CB2). STUDY: We genotyped 217 pediatric IBD patients [112 Crohn's disease (CD), 105 ulcerative colitis (UC)] and 600 controls for the CB2-Q63R variant by Taqman assay. Data were collected from clinical records on age at diagnosis, disease activity, duration and location, extraintestinal manifestations, therapy, clinical relapses, and need for surgery. RESULTS: We found a significant association of the CB2-R63 variant with IBD (allele frequencies, P=0.04; genotype distributions, P=0.0006), in particular with CD (allele frequencies, P=0.002; genotype distributions, P=0.00005) and with UC only for genotype distributions (P=0.03). RR carriers showed an increased risk for developing IBD [odds ratio (OR)=1.82; P=0.0002 for IBD; OR=2.02; P=10 for CD; OR=1.63; P=0.02 for UC at 95% confidence interval]. Upon genotype-phenotype evaluation, RR patients showed an increased frequency of moderate-to-severe disease activity at diagnosis in the case of both CD and UC (P=0.01 and P=0.02, respectively) and also an earlier clinical relapse in UC (P=0.04). In UC, all the clinical features related to the CB2 risk allele were still significantly associated with the variant when analyzed using a multivariate logistic regression model (P=0.001). CONCLUSIONS: The CB2-Q63R variant contributes to the risk for pediatric IBD, in particular CD. The R63 variant is associated with a more severe phenotype in both UC and CD. Taken together, our data point toward the involvement of the CB2 receptor in the pathogenesis and clinical features of pediatric IBD.

Cytokine production profile in intestinal mucosa of paediatric inflammatory bowel disease.

In the recent years, the incidence of inflammatory bowel disease (IBD) has dramatically increased in young subjects, however, the pathogenesis of paediatric IBD is poorly investigated. In this study we aimed to evaluate the cytokine pattern and the phenotype of cytokine producing cells in the intestinal mucosa of paediatric patients affected by Crohn's disease (CD) or ulcerative colitis (UC) and of non-IBD healthy controls (HC). Cytokine (IL-15, TNF-α, INF-γ) production was analyzed at basal condition and after mitogen stimulation either intracellularly by flow cytometry or in intestinal cell culture supernatants by enzyme-linked immunosorbent assay (ELISA). A higher frequency of enterocytes (EpCam+ cells) was observed in UC patients compared to CD or HC. An expansion of enterocytes producing IL-15 and TNF-α were found in IBD patients compared to HC. A marked expression of IL-15 in the intestinal epithelium of IBD patients was further confirmed by immunohistochemistry. Myeloid dendritic (CD11c+) cells producing TNF-α and INF-γ were increased in IBD biopsies. Unexpectedly, only after a strong mitogen stimulus, as phytohaemagglutinin, the frequency of CD3+ cells producing IFN-γ was increased in IBD compared to control intestinal mucosa. Interestingly, functional studies performed on organ cultures of intestinal biopsies with neutralizing anti-IL-15 monoclonal antibody showed a marked reduction of mononuclear cell activation, proliferation of crypt enterocytes, as well as a reduction of TNF-α release in organ culture supernatants. In conclusion, we found that in the gut mucosa of IBD children both enterocytes and dendritic cells produce proinflammatory cytokines. The over-expression of IL-15 by enterocytes in IBD intestine and the reduced IBD inflammation by IL-15 blockage suggests that this cytokine could be a therapeutic target in IBD.

Impact of Environmental and Familial Factors in a Cohort of Pediatric Patients With Inflammatory Bowel Disease.

OBJECTIVES: The primary role of environment on inflammatory bowel disease (IBD) onset has been recently stressed. We aimed to investigate the effect of environmental factors in an IBD pediatric cohort. METHODS: A total of 467 subjects (264 IBD and 203 controls) were enrolled. All patients underwent a questionnaire including 5 different groups of environmental risk factors: family history of IBD and autoimmune diseases, perinatal period, home amenities and domestic hygiene, childhood diseases and vaccinations, and diet. RESULTS: In a multivariate model, mother's degree (odds ratio [OR]: 5.5; 2.5-11.6), duration of breast feeding >3rd month (OR: 4.3; 1.6-10.5), father's employment (OR: 3.7; 1.2-8.7), gluten introduction <6th month (OR: 2.8; 1.5-5), number of siblings <2 (OR: 2.8; 1.5-5.3), and family history of autoimmune diseases (OR: 2.7; 1.4-5.3) were significant risk factors for Crohn disease. Low adherence to Mediterranean diet (OR: 2.3; 1.2-4.5), gluten introduction <6th month (OR: 2.8; 1.6-4.9), and number of siblings <2 (OR: 2; 1.1-3.6) were significant risk factors for ulcerative colitis. Owning pets (OR: 0.3; 0.1-0.7) and bed sharing (OR: 0.2; 0.1-0.6) were protective factors for Crohn disease, whereas owning pets (OR: 0.4; 0.2-0.8) and family parasitosis (OR: 0.07; 0.01-0.4) were protective factors for ulcerative colitis. CONCLUSIONS: Our study confirms that environmental factors are closely linked to IBD onset and may partly explain IBD rise in developed countries.