STEP-CD study: ustekinumab use in paediatric Crohn's disease-a multicentre retrospective study from paediatric IBD Porto group of ESPGHAN.

Ustekinumab is an effective therapy for adult Crohn's disease (CD), but data in paediatric CD patients are scarce. The aim of the study was to describe the real-life effectiveness and safety of ustekinumab in paediatric CD. This is a multicentre review of children with Crohn's disease treated with ustekinumab. The aim of our study was to describe the effectiveness and safety of ustekinumab in paediatric real-life practice. This is a study of the Paediatric IBD (inflammatory bowel disease) Porto group of ESPGHAN. Corticosteroid (CS)- and exclusive enteral nutrition (EEN)-free remission, defined as weighted Paediatric Crohn's Disease Activity Index (wPCDAI) < 12.5, and physician global assessment (PGA) were determined at weeks 12 and 52. A total of 101 children were included at a median age of 15.4 years (IQR 12.7-17.2) with a median follow-up of 7.4 months (IQR 5.6-11.8). Ninety-nine percent had received prior anti-TNF, 63% ≥ 2 anti-TNFα therapies and 22% vedolizumab. Baseline median wPCDAI was 39 (IQR 25-57.5) (71 (70%) patients with moderate-severe activity). Weeks 12 and 52 CS- and EEN-free remission were both 40.5%. Clinical response at week 6, iv induction route and older age at onset of ustekinumab treatment were predictive factors associated with clinical remission at week 12. Seven minor adverse events probably related to ustekinumab were reported. One patient died from an unrelated cause.  Conclusion: Our results suggest that ustekinumab is effective and safe in children with chronically active or refractory CD. What is Known: • Ustekinumab is an effective therapy for adult moderate to severe Crohn's disease (CD). • Off-label use of ustekinumab in children is increasing especially in anti-TNF refractory CD. What is New: • Is the largest cohort of real-world use of ustekinumab in paediatric CD to date. • Clinical response at week 6, iv induction and older age at onset of ustekinumab were predictive factors associated with clinical response at week 12.

Advantages of Proactive Therapeutic Drug Monitoring in a Prospective Cohort of Children With Inflammatory Bowel Disease Treated With Anti-Tumour Necrosis Factor.

ABSTRACT: Few studies have addressed whether proactive therapeutic drug monitoring (TDM) results in improved clinical outcomes in children with inflammatory bowel disease (IBD) treated with anti-tumour necrosis factor. The aim of this study was to investigate the impact of using proactive TDM in this patient group.Pilot single-centre observational study to accrue data on patients managed with proactive TDM.More patients in the proactive TDM cohort were managed by escalating the infliximab (IFX) regime (P < 0.001). The need for switching to different biologics was significantly lower in this patient group (P < 0.001).The introduction of proactive TDM resulted in a significant reduction of patients requiring switch of their primary biologic. The results of this study are indicators that proactive TDM offers a better method of managing children with IBD on IFX therapy.

Histology at diagnostic gastroscopy predicts outcome after intestinal resection in pediatric Crohn's disease.

BACKGROUND AND AIM: Pediatric Crohn's disease (CD) has been shown to have a high recurrence rate following surgical resection. Risk factors for postoperative CD recurrence in children are not well known. The aim of this study was to identify factors influencing postoperative recurrence in pediatric CD. METHODS: Pediatric CD patients who underwent surgical resection with primary anastomosis with a minimum follow up of 2 years were identified from databases at the Royal London Hospital and Massachusetts General Hospital. Patients were subdivided into a recurrence group defined by clinical, endoscopic, histological, radiological and/or surgical outcomes, and a nonrecurrence group. Patient demographics, initial gastroscopy and colonoscopy findings, Paris classification, and preoperative and postoperative pharmacotherapy were analyzed. RESULTS: Ninety-six children who underwent an ileal or ileocolonic resection with primary anastomosis were identified. Fifty-seven children had postoperative recurrence. Recurrence was associated with abnormal initial gastroscopy findings (P = 0.0077), ileocolonic disease location (P = 0.03), and perianal disease involvement (P = 0.04). Patients with abnormal initial gastroscopy had higher rates of relapse (hazard ratio 3.42, 95% confidence interval [CI] [1.86-6.30], P = 0.001). Multivariate analysis demonstrated that abnormal diagnostic gastroscopy histology was a significant independent predictor of postoperative recurrence in this cohort (odds ratio 1.33, 95% CI [1.04-1.70], P = 0.024). The most common histological abnormality was non-Helicobacter gastritis, found in 29/46 (63%). CONCLUSION: This dual-center study has shown that the presence of upper gastrointestinal tract inflammation, especially non-Helicobacter gastritis, at the time of diagnosis, is associated with an increased risk of postoperative recurrence in pediatric CD.

EPCAM mutation update: Variants associated with congenital tufting enteropathy and Lynch syndrome.

The epithelial cell adhesion molecule gene (EPCAM, previously known as TACSTD1 or TROP1) encodes a membrane-bound protein that is localized to the basolateral membrane of epithelial cells and is overexpressed in some tumors. Biallelic mutations in EPCAM cause congenital tufting enteropathy (CTE), which is a rare chronic diarrheal disorder presenting in infancy. Monoallelic deletions of the 3' end of EPCAM that silence the downstream gene, MSH2, cause a form of Lynch syndrome, which is a cancer predisposition syndrome associated with loss of DNA mismatch repair. Here, we report 13 novel EPCAM mutations from 17 CTE patients from two separate centers, review EPCAM mutations associated with CTE and Lynch syndrome, and structurally model pathogenic missense mutations. Statistical analyses indicate that the c.499dupC (previously reported as c.498insC) frameshift mutation was associated with more severe treatment regimens and greater mortality in CTE, whereas the c.556-14A>G and c.491+1G>A splice site mutations were not correlated with treatments or outcomes significantly different than random simulation. These findings suggest that genotype-phenotype correlations may be useful in contributing to management decisions of CTE patients. Depending on the type and nature of EPCAM mutation, one of two unrelated diseases may occur, CTE or Lynch syndrome.

Clinical Presentation and Outcomes of Diagnostic Endoscopy in Newly Presenting Children With Gastrointestinal Symptoms.

OBJECTIVES: Paediatric endoscopy is an important diagnostic tool; however, there is little published data to guide clinicians in selecting patients for endoscopy. This study aimed to evaluate a single centre's experience of newly presenting children focusing on presenting symptoms, investigations, and diagnostic yield. METHODS: Clinical factors and endoscopic plus histological findings over a 6-month period were assessed. Only first diagnostic endoscopies were included. All biopsies were reviewed in a weekly histopathology multidisciplinary team meeting with a final agreed outcome. Abnormal histology was used as the criterion standard for reporting abnormality. RESULTS: A total of 218 endoscopies were reviewed in 164 children. Approximately 65% were histologically normal (49% of children had macroscopically and histologically normal findings). Macroscopic and histological abnormalities (respectively) were 44% and 28% of oesophagogastroduodenoscopy (OGD) patients, 25% and 25% of colonoscopy alone, and 53% and 53% of those undergoing both OGD and colonoscopy (OGD&Col). For OGD-only patients, excluding those with raised anti-tissue transglutaminase antibodies, vomiting led to the highest rate of abnormal histology (22%). For colonoscopy-only and OGD&Col patients, per rectum bleeding led to the highest rates of abnormal histology (14% and 29%, respectively), after excluding those with laboratory abnormalities (anaemia and raised erythrocyte sedimentation rate) suggestive of inflammatory bowel disease. CONCLUSIONS: This study showed that half of all first diagnostic endoscopies in our unit had neither macroscopic nor histological abnormalities. There was discrepancy between macroscopic abnormalities and histological findings in OGD. Prospective studies are needed to develop guidelines in appropriately predicting abnormality and selecting patients for endoscopy.

HBV DNA Integration and Clonal Hepatocyte Expansion in Chronic Hepatitis B Patients Considered Immune Tolerant.

BACKGROUND & AIMS: Chronic infection with hepatitis B virus (HBV) progresses through different phases. The first, called the immune-tolerant phase, has been associated with a lack of disease activity. We examined HBV-DNA integration, clonal hepatocyte expansion, HBV antigen expression, and HBV-specific immune responses in patients in the immune-tolerant phase to assess whether this designation is appropriate or if there is evidence of disease activity. METHODS: We studied HBV-DNA integration, clonal hepatocyte expansion, and expression of hepatitis B surface antigen and core antigen in liver tissues from 26 patients with chronic HBV infection (ages, 14-39 y); 9 patients were positive for hepatitis B e antigen (HBeAg) in the immune-tolerant phase and were matched for age with 10 HBeAg-positive patients with active disease and 7 HBeAg-negative patients with active disease. Peripheral blood samples were collected and HBV-specific T cells were quantified for each group. RESULTS: Detection of HBV antigens differed among groups. However, unexpectedly high numbers of HBV-DNA integrations, randomly distributed among chromosomes, were detected in all groups. Clonal hepatocyte expansion in patients considered immune tolerant also was greater than expected, potentially in response to hepatocyte turnover mediated by HBV-specific T cells, which were detected in peripheral blood cells from patients in all phases of infection. CONCLUSIONS: We measured HBV-specific T cells, HBV-DNA integration, and clonal hepatocyte expansion in different disease phases of young patients with chronic hepatitis B, with emphasis on the so-called immune-tolerant phase. A high level of HBV-DNA integration and clonal hepatocyte expansion in patients considered immune tolerant indicated that hepatocarcinogenesis could be underway-even in patients with early stage chronic HBV infection. Our findings do not support the concepts that this phase is devoid of markers of disease progression or that an immune response has not been initiated. We propose that this early phase be called a high-replication, low-inflammation stage. The timing of therapeutic interventions to minimize further genetic damage to the hepatocyte population should be reconsidered.

Molecular mechanistic explanation for the spectrum of cholestatic disease caused by the S320F variant of ABCB4.

UNLABELLED: ABCB4 flops phosphatidylcholine into the bile canaliculus to protect the biliary tree from the detergent activity of bile salts. Homozygous-null ABCB4 mutations cause the childhood liver disease, progressive familial intrahepatic cholestasis, but cause and effect is less clear, with many missense mutations linked to less severe cholestatic diseases. ABCB4(S320F), in particular, is described in 13 patients, including in heterozygosity with ABCB4(A286V), ABCB4(A953D), and null mutants, whose symptoms cover the spectrum of cholestatic disease. We sought to define the impact of these mutations on the floppase, explain the link with multiple conditions at the molecular level, and investigate the potential for reversal. ABCB4(S320F), ABCB4(A286V), and ABCB4(A953D) expression was engineered in naïve cultured cells. Floppase expression, localization, and activity were measured by western blot, confocal microscopy, and lipid transport assays, respectively. ABCB4(S320F) was fully active for floppase activity but expression at the plasma membrane was reduced to 50%. ABCB4(A286V) expressed and trafficked efficiently but could not flop lipid, and ABCB4(A953D) expressed poorly and was impaired in floppase activity. Proteasome inhibition stabilized nascent ABCB4(S320F) and ABCB4(A953D) but did not improve plasma membrane localization. Cyclosporin-A improved plasma membrane localization of both ABCB4(S320F) and ABCB4(A953D), but inhibited floppase activity. CONCLUSION: The level of ABCB4 functionality correlates with, and is the primary determinant of, cholestatic disease severity in these patients. ABCB4(S320F) homozygosity, with half the normal level of ABCB4, is the tipping point between more benign and potentially fatal cholestasis and makes these patients more acutely sensitive to environmental effects. Cyclosporin-A increased expression of ABCB4(S320F) and ABCB4(A953D), suggesting that chemical chaperones could be exploited for therapeutic benefit to usher in a new era of personalized medicine for patients with ABCB4-dependent cholestatic disease.

The impact of age, disease severity, and BMI on bone health and growth in children and young people with Crohn's disease.

Objectives: The objective of this study was to explore the correlation between paediatric Crohn's disease (CD) characteristics, bone health and growth parameters at diagnosis and follow-up. Methods: Retrospective data was collected for 47 children aged 4-16 who were newly diagnosed with CD between January 2018 and December 2019. Mean follow-up time was 2.5 years. Results: Eleven (24%) children had growth delay at diagnosis, which persisted in 4 (44%) of 9 recorded children at follow-up. Of the 35 children tested, 20 (57%) had inadequate Vitamin D levels (<50 mmol/L) at diagnosis. Thirty-seven (79%) children had a dual-energy X-ray absorptiometry scan at diagnosis, with 20 of them having at least 1 low Z-score. Children with poorer bone mineral density and bone mineral concentration Z-scores for age had a younger age at diagnosis (p = .042 and p = .021), more severe disease (p = .04 and p = .029) and a lower BMI (p < .001) at diagnosis. Children diagnosed with CD ≥11 years had a lower-than-expected height velocity (p < .0001 and p < .001). Multivariate regression analysis demonstrated an older age of diagnosis was a significant predictor of a lower height velocity at follow-up. Conclusion: Disease severity and age of diagnosis are important CD-related factors that influence bone health and growth. Vitamin D is an accessible component that if optimised can improve all three factors. Monitoring and optimising each aspect systematically has the potential to enable children to achieve their bone health and growth potentials.

Preserved T-cell function in children and young adults with immune-tolerant chronic hepatitis B.

BACKGROUND & AIMS: Chronic hepatitis B (CHB) infection acquired perinatally or in early childhood has been associated with a prolonged phase of immune tolerance from viral exposure into early adulthood. The immune-tolerant phase of the disease is characterized by high levels of hepatitis B virus (HBV) DNA and normal liver biochemistry, with minimal or no fibrosis. We investigated whether the age of patients with CHB affects their antiviral immunity and whether children and young adults have a veritable state of immunologic tolerance. METHODS: We isolated T cells from different age groups of patients with CHB and used flow cytometric methods to measure production of effector and inflammatory cytokines (interferon, tumor necrosis factor, interleukin [IL]-17A, IL-22, and IL-8), T-helper (Th)2 cytokines (IL-10, IL-4), Th1 cytokines (IL-2 and IL-21), and the CC chemokine CCL3 (MIP-1). We also measured markers of T-cell exhaustion or inhibition (PD-1, LAG-3, TIM3, LAIR-1, and CTLA-4) and HBV-specific T cells. RESULTS: Young patients with CHB have a Th1-cell cytokine profile and a partial profile of T-cell exhaustion. Direct quantification of the HBV-specific T-cell response showed that young patients with CHB have more HBV-specific T cells with the ability to proliferate and produce cytokines than adult patients with CHB. CONCLUSIONS: HBV infection in younger patients is not associated with an immune profile of T-cell tolerance. On the contrary, children and young adults with chronic HBV infection have an HBV-specific immune profile that is less compromised than that observed in older patients.

Mutations in a Sar1 GTPase of COPII vesicles are associated with lipid absorption disorders.

Dietary fat is an important source of nutrition. Here we identify eight mutations in SARA2 that are associated with three severe disorders of fat malabsorption. The Sar1 family of proteins initiates the intracellular transport of proteins in COPII (coat protein)-coated vesicles. Our data suggest that chylomicrons, which vastly exceed the size of typical COPII vesicles, are selectively recruited by the COPII machinery for transport through the secretory pathways of the cell.

Inhibition of NF-κB signaling in human dendritic cells by the enteropathogenic Escherichia coli effector protein NleE.

Intestinal dendritic cells (DCs) send processes between epithelial cells into the gut lumen to sample pathogens. Noninvasive enteropathogenic Escherichia coli (EPEC) colonize the gut using a type three secretion system (T3SS) to inject effector proteins into epithelial cells. We hypothesized that EPEC might also inject proteins into DC processes to dampen immune recognition. Using a T3SS-linked fluorescence resonance energy transfer-based system we show that EPEC injects effectors into in vitro grown human myeloid DCs. Injected cells emit a blue signal due to cleavage of the green fluorescence resonance energy transfer-based substrate CCF2/AM by ß-lactamase. When cultured with a mutant EPEC unable to translocate effector proteins, myeloid DCs show rapid activation of NF-κB, secrete large amounts of proinflammatory cytokines and increase expression of CD80, CD83, and CD86, whereas wild-type EPEC barely elicits cytokine production and shuts off nuclear translocation of NF-κB p65. By deleting effector protein genes, we identified NleE as being critical for this effect. Expression of NleE in HeLa cells completely prevented nuclear p65 accumulation in response to IL1-ß, and luciferase production in an NF-κB reporter cell line. DCs cocultured with wild-type EPEC or NleE-complemented strains were less potent at inducing MLR. EPEC was also able to inject effectors into DCs sending processes through model gut epithelium in a transwell system and into Peyer's patch myeloid DCs. Thus, EPEC translocate effectors into human DCs to dampen the inflammatory response elicited by its own pathogen-associated molecular patterns.

Optimal assessment of paediatric IBD with MRI and barium follow-through.

OBJECTIVES: The present UK criterion standard for assessing children with suspected inflammatory bowel disease (IBD) is upper endoscopy, ileocolonoscopy, and barium follow-through (BaFT). Significant doses of radiation, unpalatable contrast, and volume intolerance are involved with BaFT. Practice in investigating Crohn disease (CD) is changing with the increasing use of magnetic resonance imaging (MRI). The aim of the present study was to compare BaFT and a new abdominal MRI protocol in a paediatric IBD population. METHODS: All consecutive patients with a new diagnosis of IBD or requiring reassessment from September 2008 to December 2010 were investigated with both abdominal MRI and BaFT in accordance with a specific local paediatric IBD protocol. The studies were reported by nonblinded radiologists with an interest in gastrointestinal imaging. The reports were compared in conjunction with case note review. RESULTS: Eighty-seven patients underwent both BaFT and MRI abdomen. Thirty-one percent of patients had additional pathology on MRI, not seen on the BaFT. Sixty-seven percent of patients (n=59) had an MRI finding equivalent to BaFT. Using histology as a criterion standard for detecting terminal ileal disease, BaFT had a sensitivity and specificity of 76% and 67%, and MRI had a sensitivity and specificity of 83% and 95%, respectively. CONCLUSIONS: This is the largest series of small bowel MRI in a paediatric population. MRI reports were at least equivalent to BaFT. MRI had higher sensitivity and, particularly, specificity in detecting terminal ileal pathology. These findings suggest that MRI should become the criterion standard investigation in children with IBD in centres with appropriate expertise, with zero radiation exposure being highly advantageous.

Use of faecal immunochemical testing as an alternative to faecal calprotectin in children.

BACKGROUND: Faecal calprotectin has been widely used as a non-invasive marker of intestinal inflammation in children. Measurement of faecal haemoglobin using faecal immunochemical test is well established in adults for detection of colorectal cancer. In adults, faecal haemoglobin has been recommended as a reliable tool to aid identification of those at low risk of significant bowel disease and has also been used in inflammatory bowel disease to assess mucosal healing. AIMS: We aimed to evaluate the performance of faecal haemoglobin in the paediatric population and compare it with faecal calprotectin. METHODS: Children being assessed in the paediatric gastroenterology clinic for bowel symptoms had a sample sent for both faecal calprotectin and faecal haemoglobin. Samples were collected over a 10-month period from November 2018 to September 2019. Faecal haemoglobin was measured using an OC-Sensor. Faecal calprotectin was measured using Liason®Calprotectin. RESULTS: One hundred forty three samples were returned for faecal haemoglobin and in 107 a paired faecal calprotectin was also available. Faecal haemoglobin correlated with faecal calprotectin, Spearman's rank coefficient 0.656 (P < 0.0001). There were 35 patients with faecal haemoglobin >20 µg/g and in 32 of these patients faecal calprotectin was >200 µg/g; 74 patients with faecal haemoglobin and 38 patients with faecal calprotectin underwent colonoscopy. Patients with normal histology had faecal haemoglobin <4 µg/g; faecal haemoglobin >20 µg/g was associated with signification inflammation. CONCLUSION: Our study is the first to compare faecal haemoglobin and faecal calprotectin in a paediatric population. Results suggest that faecal haemoglobin correlates with faecal calprotectin and, as in adults, may be useful to rule out significant bowel disease. A faecal haemoglobin >20 µg/g was consistent with significant histological inflammation.

Staphylococcal enterotoxins G and I, a cause of severe but reversible neonatal enteropathy.

BACKGROUND & AIMS: Staphylococcus aureus is recognized to produce toxins A-E and toxic shock syndrome toxin-1 associated with food poisoning and toxic shock syndrome. Enterotoxins G and I co-exist in the same S aureus strains (staphylococcal enterotoxin G and staphylococcal enterotoxin I) and are implicated in scarlet fever and toxic shock. We report these enterotoxins as causative agents of 2 cases of neonatal intractable diarrhea with enteropathy. METHODS: We used a note review for this study. Stool culture, multiplex polymerase chain reaction for enterotoxin, duodenal biopsy specimens for H&E, periodic acid-Schiff staining, and electron microscopy were used. RESULTS: Infant 1 had diarrhea from age 2 weeks and was referred at age 5 weeks with weight less than the 0.4th percentile. Infant 2 was referred at age 7 weeks with 4 weeks' of diarrhea, weight less than the 0.4th percentile. Both infants were severely malnourished. Elemental feeds were not tolerated and total parenteral nutrition was required. S aureus producing staphylococcal enterotoxin G and staphylococcal enterotoxin I was isolated in stools from both infants. Clinical improvement occurred after intravenous flucloxacillin and parenteral nutrition. Histology showed subtotal villous atrophy (H&E) with abnormal brush border (periodic acid-Schiff). Electron microscopy showed severe microvilli destruction, dilated mitochondria, and lysosomes containing cellular debris. Repeat histology was normal in infant 2, age 3 months, off parenteral nutrition, showed return to normal. Currently, both infants are 2 years of age and are thriving on a normal diet. CONCLUSIONS: Staphylococcal enterotoxin G- and I-induced enteropathy is a life-threatening condition, causing reversible disruption of enterocyte ultrastructure that responds well to supportive treatment with flucloxacillin and parenteral nutrition This condition should be a differential diagnosis of neonatal early onset diarrhea.

An unusual case of seronegative, 16S PCR positive Brucella infection.

INTRODUCTION: Brucella is a zoonotic infection commonly diagnosed by isolation of the organism from blood culture or positive serological testing. It is an uncommon cause of a pyrexia of unknown origin in the United Kingdom. CASE PRESENTATION: We describe the case of a 14-year-old girl with no history of travel who presented with pyrexia, weight loss, arthralgia, multiple splenic abscesses and a subsequent pleural effusion, the latter of which isolated a Brucella species on 16S rRNA PCR. The patient responded well to initiation of treatment for brucellosis and on repeat imaging, after 3 months, the splenic abscesses had resolved. CONCLUSION: This unique case demonstrates uncommon complications of brucellosis and the challenges of diagnosing the organism, the latter of which can be alleviated by the utilization of molecularbased technologies. This patient had a negative serology result for brucellosis, which highlights the need to interpret serology results with caution in non-endemic regions for brucellosis.

Epidemiology and clinical features of childhood chronic hepatitis B infection diagnosed in England.

BACKGROUND: This study aimed to estimate the prevalence of childhood chronic hepatitis B (CHB) infection diagnosed in England using capture-recapture analysis of 2 independent data sources and to describe the clinical and epidemiological characteristics, management, complications and outcome of children with CHB. METHODS: Pediatric specialists were contacted to report all CHB cases in children aged <16 years and complete a standardized questionnaire. Capture-recapture analysis of cases diagnosed during 2001-2009 using 2 independent data sources was performed to estimate the prevalence of childhood CHB. RESULTS: Capture-recapture analysis estimated 448 diagnosed CHB cases (prevalence, 4.6/100,000) in England, of whom only 44% had been referred for specialist follow up. Clinical information for 325 cases under specialist care revealed that half the cases (n = 164, 50%) had been born overseas, mainly Sub-Saharan Africa and Eastern Europe, whereas half the UK-born children were either Pakistani (25%) or Chinese (25%). Most children (n = 216, 66%) were asymptomatic, with only 60 (18.5%) ever receiving any antiviral therapy, although 2 developed cirrhosis in childhood and 1 hepatocellular carcinoma. Horizontal transmission among UK-born children was identified in only 3 children born since 2001, when universal antenatal hepatitis B virus screening was introduced. Most children born to antenatally diagnosed hepatitis B virus-positive mothers (49/51, 96%) had received at least 1 hepatitis B vaccine dose after birth. CONCLUSIONS: In England, the prevalence of diagnosed childhood CHB is low, although the potential number of undiagnosed cases is difficult to estimate. Further efforts are required to strengthen the current antenatal screening program and newly diagnosed cases should be referred for specialist follow up.

Prevalence and management of anemia in children, adolescents, and adults with inflammatory bowel disease.

BACKGROUND: Children and adolescents with inflammatory bowel disease (IBD) are more likely to have Crohn's disease (CD) than ulcerative colitis (UC) and their disease tends to be more extensive and severe than in adults. We hypothesized that the prevalence of anemia would therefore be greater in children and adolescents than in adults attending IBD outpatient clinics. METHODS: Using the WHO age-adjusted definitions of anemia we assessed the prevalence, severity, type, and response to treatment of anemia in patients attending pediatric, adolescent, and adult IBD clinics at our hospital. RESULTS: The prevalence of anemia was 70% (41/59) in children, 42% (24/54) in adolescents, and 40% (49/124) in adults (P < 0.01). Overall, children (88% [36/41]) and adolescents (83% [20/24]) were more often iron-deficient than adults (55% [27/49]) (P < 0.01). Multivariate logistic regression showed that both active disease (odds ratio [OR], 4.7 95% confidence interval [CI], 2.5, 8.8) and attending the pediatric clinic (OR 3.7; 95% CI, 1.6, 8.4) but not the adolescent clinic predicted iron deficiency anemia. Fewer iron-deficient children (13% [5/36]) than adolescents (30% [6/20]) or adults (48% [13/27]) had been given oral iron (P < 0.05); none had received intravenous iron compared with 30% (6/20) adolescents and 41% (11/27) adults (P < 0.0001). CONCLUSIONS: Anemia is even more common in children than in older IBD patients. Oral iron was given to half of adolescents and adults but, despite similar tolerance and efficacy, only a quarter of children with iron-deficient anemia. Reasons for the apparent underutilization of iron therapy include a perceived lack of benefit and concerns about side effects, including worsening of IBD activity.