Large-scale sequencing identifies multiple genes and rare variants associated with Crohn's disease susceptibility

Genome-wide association studies (GWASs) have identified hundreds of loci associated with Crohn's disease (CD). However, as with all complex diseases, robust identification of the genes dysregulated by noncoding variants typically driving GWAS discoveries has been challenging. Here, to complement GWASs and better define actionable biological targets, we analyzed sequence data from more than 30,000 patients with CD and 80,000 population controls. We directly implicate ten genes in general onset CD for the first time to our knowledge via association to coding variation, four of which lie within established CD GWAS loci. In nine instances, a single coding variant is significantly associated, and in the tenth, ATG4C, we see additionally a significantly increased burden of very rare coding variants in CD cases. In addition to reiterating the central role of innate and adaptive immune cells as well as autophagy in CD pathogenesis, these newly associated genes highlight the emerging role of mesenchymal cells in the development and maintenance of intestinal inflammation.

Interactions between the intestinal microbiota and epigenome in individuals with autism spectrum disorder

Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized by variable impairment of cognitive function and interpersonal relationships. Furthermore, some individuals with ASD have gastrointestinal disorders that have been correlated with impairments in intestinal microbiota. Gut microbiota are important not only for intestinal health, but also for many other functions including food digestion, energy production, immune system regulation, and, according to current data, behavior. Disruption of the indigenous microbiota, microbial dysbiosis (imbalance between microorganisms present in the gut), overgrowth of potentially pathogenic microorganisms, a less diverse microbiome, or lower levels of beneficial bacteria in children with ASD can affect behavior. Metabolome analysis in children with ASD has identified perturbations in multiple metabolic pathways that might be associated with cognitive functions. Recent studies have shown that the intestinal microbiome provides environmental signals that can modify host response to stimuli by modifying the host epigenome, which affects DNA methylation, histone modification, and non-coding RNAs. The most studied microbiota-produced epigenetic modifiers are short-chain fatty acids, although other products of intestinal microbiota might also cause epigenetic modifications in the host's DNA. Here we review evidence suggesting that epigenetic alterations caused by modification of gene expression play an important role in understanding ASD.

Lymphoma in Pediatric-Onset Inflammatory Bowel Disease Treated with Infliximab Monotherapy: A Case Series

BACKGROUND

Inflammatory bowel diseases (IBD) are often treated with anti-tumor necrosis factor alpha (anti-TNFα) medications. Concomitant treatment of IBD with anti-TNFα agents and immunomodulators appears to be associated with an increased risk for lymphoma.

METHODS

Patients who developed lymphoma while on monotherapy with an anti-TNFα agent were identified at three centers. Institutional Review Board approval was obtained.

RESULTS

Five adolescents and young adult patients with pediatric-onset IBD who were treated with infliximab (IFX) without exposure to thiopurines were subsequently diagnosed with lymphoma. Three of the five patients had bone involvement at presentation. Epstein-Barr virus was positive in 2 cases. Median time from diagnosis of IBD and exposure to IFX prior to diagnosis of lymphoma was 5 and 4.3 years, respectively.

CONCLUSIONS

This case series reports long-term follow-up for young patients with IBD who were treated with IFX monotherapy and developed lymphoma. Three of the five patients had bone involvement. In general, the risk of lymphoma following exposure to anti-TNFα medications alone remains low, but the incidence of primary bone lymphomas in IBD has not been reported. Studies examining longer exposure times may be needed to determine the true lymphoma risk in patients treated with IFX monotherapy.

Importance of early detection of infantile inflammatory bowel disease with defective IL-10 pathway: A case report

RATIONALE

Infantile inflammatory bowel disease (IBD) is an extremely rare subgroup of IBD that includes patients whose age of onset is younger than 2 years old. These patients can have more surgical interventions, and a severe and refractory disease course with higher rates of conventional treatment failure. Monogenic defects play an important role in this subgroup of IBD, and identification of the underlying defect can guide the therapeutic approach.

PATIENT CONCERNS

In 2007, a 4-month-old girl from a nonconsanguineous family presenting with anal fistula, chronic diarrhea, and failure to thrive. She underwent multiple surgical repairs but continued to have persistent colitis and perianal fistulas.

DIAGNOSIS

Crohn's disease was confirmed by endoscopic and histologic finding.

INTERVENTION

Conventional pediatric IBD therapy including multiple surgical interventions and antitumor necrosis factor alpha agents were applied.

OUTCOMES

The patient did not respond to conventional pediatric IBD therapy. Interleukin-10 (IL-10) receptor mutation was discovered by whole-exome sequencing and defective IL-10 signaling was proved by functional test of IL-10 signaling pathway by the age of 12. The patient is currently awaiting hematopoietic stem cell transplantation.

LESSONS

Early detection of underlying genetic causes of patients with infantile-IBD is crucial, since it may prevent patients from undergoing unnecessary surgeries and adverse effects from ineffective medical therapies. Moreover, infantile-IBD patients with complex perianal disease, intractable early onset enterocolitis and extraintestinal manifestations including oral ulcers and skin folliculitis, should undergo genetic and functional testing for IL-10 pathway defect.

Bacterial dysbiosis predicts the diagnosis of Crohn's disease in Saudi children

BACKGROUND

Studies have reached different conclusions regarding the accuracy of dysbiosis in predicting the diagnosis of Crohn's disease (CD). The aim of this report is to assess the utility of mucosal and fecal microbial dysbiosis as predictors in the diagnosis of this condition in Saudi children.

METHODS

Tissue and fecal samples were collected prospectively from children with final diagnosis of CD and from controls. Bacterial DNA was extracted and sequenced using Illumina MiSeq chemistry. The abundance and diversity of bacteria in tissue and fecal samples were determined in relation to controls. Sparse logistic regression was calculated to predict the diagnosis of CD based on subject's microbiota profile.

RESULTS

There were 17 children with CD and 18 controls. All children were Saudis. The median age was 13.9 and 16.3 years for children with CD and controls respectively. Sex distribution showed that 11/17 (65%) of the CD and 12/18 (67%) of the control subjects were boys. The mean area under the curve (AUC) was significantly higher in stool (AUC = 0.97 ± 0.029) than in tissue samples (AUC = 0.83 ±0.055) (P < 0.001).

CONCLUSIONS

We found high AUC in mucosal and fecal samples. The higher AUC for fecal samples suggests higher accuracy in predicting the diagnosis of CD.

Additional Intestinal Mucosal Biopsy Sampling for Research Is Safe During Pediatric Endoscopic Procedures

Advancing the understanding of inflammatory bowel disease (IBD) pathogenesis has been facilitated by mechanistic studies that require human intestinal tissue. Enrolling pediatric subjects into these studies improves our knowledge of IBD in this underserved population. Given the additional research protections granted to children, institutional review boards (IRBs) must weigh the benefit of obtaining research biopsies against perceived risks. Although obtaining clinical biopsies from children is generally considered safe, there are only limited data on the safety of obtaining research biopsies in children.^1-6.

Gut Microbiota and Gender in Autism Spectrum Disorders

Gender dimorphism in autism spectrum disorders (ASD) is well known; however, the reasons for gender differences in autism are poorly understood. There are several hypotheses that might explain male prevalence in ASD, including increased levels of androgens, "extreme male brain," and a combination of elevated levels of prenatal testosterone in conjunction with prenatal stress. In this comprehensive review, differences in the gut microbiome and metabolome in humans and animals are described to explain gender differences in individuals with ASD, effects on behavior and social interactions and the impact of antibiotics, probiotics and fecal transplants. The bidirectional relationship between sex hormones and intestinal microbiota could also be relevant. Such interactions have been described in autoimmune diseases, but thus far, are not implicated in ASD. Since intestinal microbiota may affect behavior, it is possible that the prevalence of ASD in boys may be associated with more significant changes in the intestinal microbiome than in affected girls.

Long-term Outcomes of Paediatric Patients Admitted With Acute Severe Colitis- A Multicentre Study From the Paediatric IBD Porto Group of ESPGHAN

BACKGROUND AND AIM

Acute severe colitis [ASC] is associated with significant morbidity in paediatric patients with ulcerative colitis [UC]. Most outcome studies in ASC since tumour necrosis factor alpha [TNFα] antagonists became available have focused on the first year after admission. The aim of this study was to characterise the longer-term outcomes of paediatric patients admitted with ASC.

METHODS

This retrospective study was conducted in 25 centres across Europe and North America. Data on patients with UC aged <18 years, admitted with ASC (defined as paediatric ulcerative colitis activity index [PUCAI] score ≥65) between 2009 and 2011, were collected at discharge and 1, 3 and 5 years after admission. The primary outcome was colectomy-free rates at each time point.

RESULTS

Of the 141 patients admitted with ASC, 137 [97.1%] were treated with intravenous corticosteroids. Thirty-one [22.6%] patients were escalated to second-line therapy, mainly to infliximab. Sixteen patients [11.3%] underwent colectomy before discharge. Long-term follow-up showed colectomy-free rates were 71.3%, 66.4% and 63.6% at 1, 3 and 5 years after initial ASC admission, respectively, and were similar across different age groups. Sub-analysis of colectomy rates in patients with new-onset disease [42.5% of the cohort] yielded similar results. In a multivariate analysis, use of oral steroids in the 3 months before admission, erythrocyte sedimentation rate >70 mm/h, and albumin <2.5 g/dL, were significantly associated with 5-year colectomy risk.

CONCLUSIONS

High colectomy rates were demonstrated in paediatric UC patients admitted with ASC. Additional studies are required to determine whether intensification of anti-TNFα treatment, close therapeutic drug monitoring, and use of new drugs alter this outcome.

Multi-omics of the gut microbial ecosystem in inflammatory bowel diseases

Inflammatory bowel diseases, which include Crohn’s disease and ulcerative colitis, affect several million individuals worldwide. Crohn’s disease and ulcerative colitis are complex diseases that are heterogeneous at the clinical, immunological, molecular, genetic, and microbial levels. Individual contributing factors have been the focus of extensive research. As part of the Integrative Human Microbiome Project (HMP2 or iHMP), we followed 132 subjects for one year each to generate integrated longitudinal molecular profiles of host and microbial activity during disease (up to 24 time points each; in total 2,965 stool, biopsy, and blood specimens). Here we present the results, which provide a comprehensive view of functional dysbiosis in the gut microbiome during inflammatory bowel disease activity. We demonstrate a characteristic increase in facultative anaerobes at the expense of obligate anaerobes, as well as molecular disruptions in microbial transcription (for example, among clostridia), metabolite pools (acylcarnitines, bile acids, and short-chain fatty acids), and levels of antibodies in host serum. Periods of disease activity were also marked by increases in temporal variability, with characteristic taxonomic, functional, and biochemical shifts. Finally, integrative analysis identified microbial, biochemical, and host factors central to this dysregulation. The study’s infrastructure resources, results, and data, which are available through the Inflammatory Bowel Disease Multi’omics Database (http://ibdmdb.org), provide the most comprehensive description to date of host and microbial activities in inflammatory bowel diseases.

The Inflammatory Bowel Disease Multi’omics Database includes longitudinal data encompassing a multitude of analyses of stool, blood and biopsies of more than 100 individuals, and provides a comprehensive description of host and microbial activities in inflammatory bowel diseases.

Development of a Brief Parent-Report Screen for Common Gastrointestinal Disorders in Autism Spectrum Disorder

Gastrointestinal dysfunction in children with autism spectrum disorder (ASD) is common and associated with problem behaviors. This study describes the development of a brief, parent-report screen that relies minimally upon the child's ability to report or localize pain for identifying children with ASD at risk for one of three common gastrointestinal disorders (functional constipation, functional diarrhea, and gastroesophageal reflux disease). In a clinical sample of children with ASD, this 17-item screen identified children having one or more of these disorders with a sensitivity of 84%, specificity of 43%, and a positive predictive value of 67%. If found to be valid in an independent sample of children with ASD, the screen will be useful in both clinical practice and research.

Microbiota profile in new-onset pediatric Crohn's disease: data from a non-Western population

Background

The role of microbiota in Crohn’s disease (CD) is increasingly recognized. However, most of the reports are from Western populations. Considering the possible variation from other populations, the aim of this study was to describe the microbiota profile in children with CD in Saudi Arabia, a non-Western developing country population.

Results

Significantly more abundant genera in children with CD included Fusobacterium, Peptostreptococcus, Psychrobacter, and Acinetobacter; whereas the most significantly-depleted genera included Roseburia, Clostridium, Ruminococcus, Ruminoclostridium, Intestinibacter, Mitsuokella, Megasphaera, Streptococcus, Lactobacillus, Turicibacter, and Paludibacter. Alpha diversity was significantly reduced in stool (p = 0.03) but not in mucosa (p = 0.31). Beta diversity showed significant difference in community composition between control and CD samples (p = 0.03).

Conclusion

In this developing country, we found a pattern of microbiota in children with CD similar to Western literature, suggesting a role of recent dietary lifestyle changes in this population on microbiota structure.

Fungal dysbiosis predicts the diagnosis of pediatric Crohn’s disease

AIM

To investigate the accuracy of fungal dysbiosis in mucosa and stool for predicting the diagnosis of Crohn’s disease (CD).

METHODS

Children were prospectively enrolled in two medical centers: one university hospital and one private gastroenterology clinic in the city of Riyadh, Kingdom of Saudi Arabia. The children with confirmed diagnosis of CD by standard guidelines were considered cases, and the others were considered non-inflammatory bowel disease controls. Mucosal and stool samples were sequenced utilizing Illumina MiSeq chemistry following the manufacturer’s protocols, and abundance and diversity of fungal taxa in mucosa and stool were analyzed. Sparse logistic regression was used to predict the diagnosis of CD. The accuracy of the classifier was tested by computing the receiver operating characteristic curves with 5-fold stratified cross-validation under 100 permutations of the training data partition and the mean area under the curve (AUC) was calculated.

RESULTS

All the children were Saudi nationals. There were 15 children with CD and 20 controls. The mean age was 13.9 (range: 6.7-17.8) years for CD children and 13.9 (3.25-18.6) years for controls, and 10/15 (67%) of the CD and 13/20 (65%) of the control subjects were boys. CD locations at diagnosis were ileal (L1) in 4 and colonic (L3) in 11 children, while CD behavior was non-stricturing and non-penetrating (B1) in 12 and stricturing (B2) in 3 children. The mean AUC for the fungal dysbiosis classifier was significantly higher in stools (AUC = 0.85 ± 0.057) than in mucosa (AUC = 0.71 ± 0.067) (P < 0.001). Most fungal species were significantly more depleted in stools than mucosal samples, except for Saccharomyces cerevisiae and S. bayanus, which were significantly more abundant. Diversity was significantly more reduced in stools than in mucosa.

CONCLUSION

We found high AUC of fungal dysbiosis in fecal samples of children with CD, suggesting high accuracy in predicting diagnosis of CD.

Genetic Variation Affects C-Reactive Protein Elevations in Crohn's Disease

BACKGROUND

C-reactive protein (CRP) is a serum marker that is used to measure disease activity in Crohn's disease (CD). However, a subset of CD patients have normal CRP during flares. In rheumatoid arthritis and lupus, genetic variants can restrict CRP elevations during flares. This study sought to determine if common CRP genetic variants affect CRP values during active CD.

METHODS

Subjects with CD who participated in the Partners HealthCare BioBank were genotyped for 5 common CRP genetic variants (rs2794520, rs3122012, rs3093077, rs2808635, and rs1800947). Medical records were reviewed to determine disease activity and the highest CRP value during active CD. CRP values during active infection or malignancy at the time of the test were excluded. CRP values were compared by genotype using the Mann-Whitney test.

RESULTS

The study included 199 subjects with active CD (21 to 86 years of age). Subjects with the rs2794520 TT genotype had a lower CRP than subjects with the CC genotype (58.3 mg/L vs 28.4 mg/L, P = 0.008). Subjects with the rs1800947 CG genotype had a lower CRP than those with the CC genotype (54.3 mg/L vs 22.4 mg/L, P < 0.0001); 41.6% of TT subjects had a normal CRP compared with 24.1% of CT subjects and 16.5% of CC subjects (P = 0.041).

CONCLUSIONS

This study demonstrates that rs2794520 and rs1800947 are associated with a restriction of CRP elevations during active CD. While CRP is typically a reliable biomarker in CD, there is a subset of CD patients with a genetically determined restriction of CRP in whom other disease markers should be utilized.

Colonic Inhibition of Phosphatase and Tensin Homolog Increases Colitogenic Bacteria, Causing Development of Colitis in Il10-/- Mice

Background

Phosphatase and tensin homolog (Pten) is capable of mediating microbe-induced immune responses in the gut. Thus, Pten deficiency in the intestine accelerates colitis development in Il10-/- mice. As some ambient pollutants inhibit Pten function and exposure to ambient pollutants may increase inflammatory bowel disease (IBD) incidence, it is of interest to examine how Pten inhibition could affect colitis development in genetically susceptible hosts.

Methods

With human colonic mucosa biopsies from pediatric ulcerative colitis and non-IBD control subjects, we assessed the mRNA levels of the PTEN gene and the gene involved in IL10 responses. The data from the human tissues were corroborated by treating Il10-/-, Il10rb-/-, and wild-type C57BL/6 mice with Pten-specific inhibitor VO-OHpic. We evaluated the severity of mouse colitis by investigating the tissue histology and cytokine production. The gut microbiome was investigated by analyzing the 16S ribosomal RNA gene sequence with mouse fecal samples.

Results

PTEN and IL10RB mRNA levels were reduced in the human colonic mucosa of pediatric ulcerative colitis compared with non-IBD subjects. Intracolonic treatment of the Pten inhibitor induced colitis in Il10-/- mice, characterized by reduced body weight, marked colonic damage, and increased production of inflammatory cytokines, whereas Il10rb-/- and wild-type C57BL/6 mice treated with the inhibitor did not develop colitis. Pten inhibitor treatment changed the fecal microbiome, with increased abundance of colitogenic bacteria Bacteroides and Akkermansia in Il10-/- mice.

Conclusions

Loss of Pten function increases the levels of colitogenic bacteria in the gut, thereby inducing deleterious colitis in an Il10-deficient condition.

Genetic variants in cellular transport do not affect mesalamine response in ulcerative colitis

Background and aims

Mesalamine is commonly used to treat ulcerative colitis (UC). Although mesalamine acts topically, in vitro data suggest that intracellular transport is required for its beneficial effect. Genetic variants in mucosal transport proteins may affect this uptake, but the clinical relevance of these variants has not been studied. The aim of this study was to determine whether variants in genes involved in cellular transport affect the response to mesalamine in UC.

Methods

Subjects with UC from a 6-week clinical trial using multiple doses of mesalamine were genotyped using a genome-wide array that included common exome variants. Analysis focused on cellular transport gene variants with a minor allele frequency >5%. Mesalamine response was defined as improvement in Week 6 Physician’s Global Assessment (PGA) and non-response as a lack of improvement in Week 6 PGA. Quality control thresholds included an individual genotyping rate of >90%, SNP genotyping rate of >98%, and exclusion for subjects with cryptic relatedness. All included variants met Hardy-Weinberg equilibrium (p>0.001).

Results

457 adults with UC were included with 280 responders and 177 non-responders. There were no common variants in transporter genes that were associated with response to mesalamine. The genetic risk score of responders was similar to that of non-responders (p = 0.18). Genome-wide variants demonstrating a trend towards mesalamine response included ST8SIA5 (p = 1x10^-5).

Conclusions

Common transporter gene variants did not affect response to mesalamine in adult UC. The response to mesalamine may be due to rare genetic events or environmental factors such as the intestinal microbiome.

Identification and characterization of a novel DGAT1 missense mutation associated with congenital diarrhea

Acyl-CoA:diacylglycerol acyltransferase (DGAT)1 and DGAT2 catalyze triglyceride (TG) biosynthesis in humans. Biallelic loss-of-function mutations in human DGAT1 result in severe congenital diarrhea and protein-losing enteropathy. Additionally, pharmacologic inhibition of DGAT1 led to dose-related diarrhea in human clinical trials. Here we identify a previously unknown DGAT1 mutation in identical twins of South Asian descent. These male patients developed watery diarrhea shortly after birth, with protein-losing enteropathy and failure to thrive. Exome sequencing revealed a homozygous recessive mutation in DGAT1, c.314T>C, p.L105P. We show here that the p.L105P DGAT1 enzyme produced from the mutant allele is less abundant, resulting in partial loss of TG synthesis activity and decreased formation of lipid droplets in patient-derived primary dermal fibroblasts. Thus, in contrast with complete loss-of-function alleles of DGAT1, the p.L105P missense allele partially reduces TG synthesis activity and causes a less severe clinical phenotype. Our findings add to the growing recognition of DGAT1 deficiency as a cause of congenital diarrhea with protein-losing enteropathy and indicate that DGAT1 mutations result in a spectrum of diseases.

Improving Clinical Remission Rates in Pediatric Inflammatory Bowel Disease with Previsit Planning

Inflammatory Bowel Disease (IBD) is a chronic autoimmune inflammatory disease of the intestine which can lead to malnutrition, poor quality of life, and colon cancer.(1-4) Although there is no cure for the disease, clinical remission is the primary goal.(5) The Center for Inflammatory Bowel Disease at MassGeneral Hospital for Children (MGHfC) adopted a Previsit Planning (PVP) model to identify and discuss symptomatic patients prior to their appointments to identify specific issues that impact disease management.(6-8) The Registry from ImproveCareNow (ICN), the international Quality Improvement Collaborative for the management of Crohn's Disease and Ulcerative Colitis in pediatric and adolescent patients, was used to capture information from each ambulatory visit and hospitalization. Using the Model for Improvement framework, the team began a weekly review and made care recommendations of patients with active disease who were cared for by one physician. Interventions were modified over multiple Plan-Do-Study-Act (PDSA) improvement cycles to increase the number of providers and to include patients with mild or moderate disease activity.(9) Feedback from the providers regarding this process was elicited via a REDCap survey and the clinical remission rate was tracked using the ICN Registry. The clinical remission rate for the Center's patients increased from 77% (n=597) in September 2014 to 83% (n=585) in August 2015 and has been maintained. 78% of responding providers indicated that they found the PVP recommendations helpful "all of the time". One hundred percent who responded to the survey said that they have used at least one recommendation provided to them. PVP for management of a chronic disease in pediatrics is feasible, even in a high volume practice. This process at MGHfC has resulted in the improvement of clinical remission rate. PDSA cycles were used to document successes and failures to help guide the work. Ongoing expansion of this PVP practice to all providers continues with the anticipation of including input from patients and their families, as well.

Health Care Infrastructure for Financially Sustainable Clinical Genomics

Next-generation sequencing has evolved technically and economically into the method of choice for interrogating the genome in cancer and inherited disorders. The introduction of procedural code sets for whole-exome and genome sequencing is a milestone toward financially sustainable clinical implementation; however, achieving reimbursement is currently a major challenge. As part of a prospective quality-improvement initiative to implement the new code sets, we adopted Agile, a development methodology originally devised in software development. We implemented eight functionally distinct modules (request review, cost estimation, preauthorization, accessioning, prebilling, testing, reporting, and reimbursement consultation) and obtained feedback via an anonymous survey. We managed 50 clinical requests (January to June 2015). The fraction of pursued-to-requested cases (n = 15/50; utilization management fraction, 0.3) aimed for a high rate of preauthorizations. In 13 of 15 patients the insurance plan required preauthorization, which we obtained in 70% and ultimately achieved reimbursement in 50%. Interoperability enabled assessment of 12 different combinations of modules that underline the importance of an adaptive workflow and policy tailoring to achieve higher yields of reimbursement. The survey confirmed a positive attitude toward self-organizing teams. We acknowledge the individuals and their interactions and termed the infrastructure: human pipeline. Nontechnical barriers currently are limiting the scope and availability of clinical genomic sequencing. The presented human pipeline is one approach toward long-term financial sustainability of clinical genomics.

Detecting Microbial Dysbiosis Associated with Pediatric Crohn Disease Despite the High Variability of the Gut Microbiota

The relationship between the host and its microbiota is challenging to understand because both microbial communities and their environments are highly variable. We have developed a set of techniques based on population dynamics and information theory to address this challenge. These methods identify additional bacterial taxa associated with pediatric Crohn disease and can detect significant changes in microbial communities with fewer samples than previous statistical approaches required. We have also substantially improved the accuracy of the diagnosis based on the microbiota from stool samples, and we found that the ecological niche of a microbe predicts its role in Crohn disease. Bacteria typically residing in the lumen of healthy individuals decrease in disease, whereas bacteria typically residing on the mucosa of healthy individuals increase in disease. Our results also show that the associations with Crohn disease are evolutionarily conserved and provide a mutual information-based method to depict dysbiosis.

Exome sequencing analysis reveals variants in primary immunodeficiency genes in patients with very early onset inflammatory bowel disease

BACKGROUND & AIMS

Very early onset inflammatory bowel disease (VEO-IBD), IBD diagnosed at 5 years of age or younger, frequently presents with a different and more severe phenotype than older-onset IBD. We investigated whether patients with VEO-IBD carry rare or novel variants in genes associated with immunodeficiencies that might contribute to disease development.

METHODS

Patients with VEO-IBD and parents (when available) were recruited from the Children's Hospital of Philadelphia from March 2013 through July 2014. We analyzed DNA from 125 patients with VEO-IBD (age, 3 wk to 4 y) and 19 parents, 4 of whom also had IBD. Exome capture was performed by Agilent SureSelect V4, and sequencing was performed using the Illumina HiSeq platform. Alignment to human genome GRCh37 was achieved followed by postprocessing and variant calling. After functional annotation, candidate variants were analyzed for change in protein function, minor allele frequency less than 0.1%, and scaled combined annotation-dependent depletion scores of 10 or less. We focused on genes associated with primary immunodeficiencies and related pathways. An additional 210 exome samples from patients with pediatric IBD (n = 45) or adult-onset Crohn's disease (n = 20) and healthy individuals (controls, n = 145) were obtained from the University of Kiel, Germany, and used as control groups.

RESULTS

Four hundred genes and regions associated with primary immunodeficiency, covering approximately 6500 coding exons totaling more than 1 Mbp of coding sequence, were selected from the whole-exome data. Our analysis showed novel and rare variants within these genes that could contribute to the development of VEO-IBD, including rare heterozygous missense variants in IL10RA and previously unidentified variants in MSH5 and CD19.

CONCLUSIONS

In an exome sequence analysis of patients with VEO-IBD and their parents, we identified variants in genes that regulate B- and T-cell functions and could contribute to pathogenesis. Our analysis could lead to the identification of previously unidentified IBD-associated variants.

Fecal transplant for recurrent Clostridium difficile infection in children with and without inflammatory bowel disease

Ten children at our institution received single-infusion fecal microbiome transplant (FMT) using healthy, related screened donor stool to treat recurrent Clostridium difficile infection (RCDI) via nasogastric tube (2 patients) or colonoscopic delivery. Nine of the 10 (90%) children had resolution of their symptoms after a single-infusion FMT with follow-up of 1 month to 4 years. No concerning related adverse events were recognized during short- or long-term follow-up. Three of these children had concomitant inflammatory bowel disease and 2 of these 3 (66%) patients cleared RCDI with no clinical change in their underlying inflammatory bowel disease clinical activity as assessed by Physician's Global Assessment. All of the patients who had clinical improvement of gastrointestinal symptoms of RCDI while treated with antibiotics had lasting return of baseline health after FMT.

MicroRNA-124 regulates STAT3 expression and is down-regulated in colon tissues of pediatric patients with ulcerative colitis

BACKGROUND & AIMS

Altered levels and functions of microRNAs (miRs) have been associated with inflammatory bowel diseases (IBDs), although little is known about their roles in pediatric IBD. We investigated whether colonic mucosal miRs are altered in children with ulcerative colitis (UC).

METHODS

We used a library of 316 miRs to identify those that regulate phosphorylation of signal transducer and activator of transcription 3 (STAT3) in NCM460 human colonocytes incubated with interleukin-6. Levels of miR-124 were measured by real-time polymerase chain reaction analysis of colon biopsies from pediatric and adult patients with UC and patients without IBD (controls), and of HCT-116 colonocytes incubated with 5-aza-2'-deoxycytidine (5-AZA). Methylation of the MIR124 promoter was measured by quantitative methylation-specific polymerase chain reaction.

RESULTS

Levels of phosphorylated STAT3 and the genes it regulates (encoding vascular endothelial growth factor (VEGF), BCL2, BCLXL, and matrix metallopeptidase 9 [MMP9]) were increased in pediatric patients with UC compared with control tissues. Overexpression of miR-124, let-7, miR-125, miR-26, or miR-101 reduced STAT3 phosphorylation by ≥ 75% in NCM460 cells; miR-124 had the greatest effect. miR-124 was down-regulated specifically in colon tissues from pediatric patients with UC and directly targeted STAT3 messenger RNA (mRNA). Levels of miR-124 were decreased, whereas levels of STAT3 phosphorylation increased in colon tissues from pediatric patients with active UC compared with those with inactive disease. In addition, levels of miR-124 and STAT3 were inversely correlated in mice with experimental colitis. Down-regulation of miR-124 in tissues from children with UC was attributed to hypermethylation of its promoter region. Incubation of HCT-116 colonocytes with 5-AZA up-regulated miR-124 and reduced levels of STAT3 mRNA.

CONCLUSIONS

miR-124 appears to regulate the expression of STAT3. Reduced levels of miR-124 in colon tissues of children with active UC appear to increase expression and activity of STAT3, which could promote inflammation and the pathogenesis of UC in children.

DGAT1 mutation is linked to a congenital diarrheal disorder

Congenital diarrheal disorders (CDDs) are a collection of rare, heterogeneous enteropathies with early onset and often severe outcomes. Here, we report a family of Ashkenazi Jewish descent, with 2 out of 3 children affected by CDD. Both affected children presented 3 days after birth with severe, intractable diarrhea. One child died from complications at age 17 months. The second child showed marked improvement, with resolution of most symptoms at 10 to 12 months of age. Using exome sequencing, we identified a rare splice site mutation in the DGAT1 gene and found that both affected children were homozygous carriers. Molecular analysis of the mutant allele indicated a total loss of function, with no detectable DGAT1 protein or activity produced. The precise cause of diarrhea is unknown, but we speculate that it relates to abnormal fat absorption and buildup of DGAT substrates in the intestinal mucosa. Our results identify DGAT1 loss-of-function mutations as a rare cause of CDDs. These findings prompt concern for DGAT1 inhibition in humans, which is being assessed for treating metabolic and other diseases.

Induction and maintenance therapy with infliximab for children with moderate to severe ulcerative colitis

BACKGROUND & AIMS

We evaluated the efficacy and safety of infliximab for inducing and maintaining benefit in children with moderately to severely active ulcerative colitis (UC).

METHODS

Patients (6-17 years old) who had active UC (Mayo scores of 6-12; endoscopic subscores ≥ 2) and had not responded to or tolerated conventional treatment were given 5 mg/kg infliximab at weeks 0, 2, and 6. The primary end point was response at week 8 (decreases in Mayo scores ≥ 30% and ≥ 3 points and decreases in rectal bleeding subscores of ≥ 1 or an absolute subscore of ≤ 1). At week 8, only responders were randomly assigned to groups given infliximab every 8 or 12 weeks (q8w or q12w) and followed through week 54. Maintenance end points included pediatric UC activity index scores <10 points, defined as remission.

RESULTS

At week 8, infliximab induced a response in 73.3% of patients (44 of 60) (95% confidence interval, 62.1%-84.5%; a positive result was defined by 95% confidence interval lower limit >40%). Among responders, twice as many were in remission at week 54 after q8w (8 of 21, 38.1%) than q12w (4 of 22, 18.2%; P = .146) therapy. Assuming the q8w remission rate for responders, the overall remission rate at week 54 would be 28.6%. Serious adverse events and infusion reactions occurred in similar proportions in the q8w and q12w groups. No deaths, malignancies, opportunistic infections, tuberculosis, or delayed hypersensitivity reactions were reported.

CONCLUSIONS

Infliximab was safe and effective, inducing a response at week 8 in 73.3% of pediatric patients with moderate to severely active UC who did not respond to conventional therapy. The overall remission rate at week 54 for all enrolled patients was 28.6%, assuming the more effective q8w remission rate.

Review of the persistence of gastroesophageal reflux disease in children, adolescents and adults: does gastroesophageal reflux disease in adults sometimes begin in childhood?

OBJECTIVE

Understanding the natural history and outcomes of gastroesophageal reflux disease (GERD) in children could help to identify patients at risk of having GERD complications during adulthood. This review aimed to assess evidence of whether GERD in children or adolescents persists into adulthood.

MATERIAL AND METHODS

PubMed searches (1966-2010) identified longitudinal studies of GERD extending from childhood/infancy into adulthood, as well as longitudinal studies within pediatric age groups.

RESULTS

In one study, heartburn during childhood was more often recalled by adults with reflux symptoms than by those without (30% vs. 9%; p < 0.001), as was medication or surgery for GERD (both p < 0.01). Another study found that GERD symptoms were more common in adults diagnosed with reflux esophagitis during childhood/adolescence than in those who were not (46% vs. 30%). Regurgitation during infancy increased the risk of feeding problems after 1 year (odds ratio 4.2 (95% confidence interval: 1.4-12.0)) and of reflux symptoms at 9 years of age (relative risk 2.3 (95% confidence interval: 1.3-4.0)). In one study, abnormal esophageal histology persisted in infants after 12 months without reflux symptoms. A proportion (59-100%: three studies) of patients with reflux symptoms and/or reflux esophagitis during the pediatric years still required treatment after 1-8 years. In another study, however, just 7% of patients with healed reflux esophagitis relapsed after 9 months without treatment.

CONCLUSION

The limited available evidence suggests that some infants, children, and adolescents with GERD are more likely than those without GERD to have symptoms later in life.

Intestinal disaccharidase activity in patients with autism: effect of age, gender, and intestinal inflammation

Intestinal disaccharidase activities were measured in 199 individuals with autism to determine the frequency of enzyme deficiency. All patients had duodenal biopsies that were evaluated morphologically and assayed for lactase, sucrase, and maltase activity. Frequency of lactase deficiency was 58% in autistic children ≤ 5 years old and 65% in older patients. As would be expected, patients with autism at age 5 > years demonstrated significant decline in lactase activity (24%, p = .02) in comparison with ≤ 5 years old autistic patients. Boys ≤ 5 years old with autism had 1.7 fold lower lactase activity than girls with autism (p = .02). Only 6% of autistic patients had intestinal inflammation. Lactase deficiency not associated with intestinal inflammation or injury is common in autistic children and may contribute to abdominal discomfort, pain and observed aberrant behavior. Most autistic children with lactose intolerance are not identified by clinical history.

Safety and efficacy of maintenance infliximab therapy for moderate-to-severe Crohn's disease in children: REACH open-label extension

OBJECTIVE

Assess long-term effects of maintenance infliximab therapy in children with moderately-to-severely active Crohn's disease.

RESEARCH DESIGN AND METHODS

One hundred twelve patients with a Pediatric Crohn's Disease Activity Index (PCDAI) score >30 received infliximab 5 mg/kg at weeks 0, 2, and 6 in the REACH study. Patients considered responders at week 10 were randomized to infliximab 5 mg/kg every 8 (q8w) or 12 (q12w) weeks. Patients who completed treatment through week 46, and who the investigator believed would benefit from continued treatment, could enter the open-label extension (OLE) and receive up to three additional years of infliximab. No hypothesis testing was performed.

CLINICAL TRIAL REGISTRATION

www.clinicaltrials.gov, identifier: NCT0020767.

RESULTS

Sixty children entered the OLE: 33, 12, and 15 patients were receiving infliximab 5 mg/kg q8w, 5 mg/kg q12w, and 10 mg/kg q8w, respectively, at extension entry. Patients receiving infliximab for up to 3 years during the OLE maintained clinical benefit, with approximately 80% of patients consistently having no to mild disease activity per the physician's global assessment and very good to fair health in the past 2 weeks per the patient and parent/guardian global assessments. Patients with ≥1-year delay in bone age at baseline trended toward improvement in height during the OLE. Respiratory system disorders, most commonly upper respiratory infections, were the most prevalent adverse events reported; six (10%) patients had serious infections.

CONCLUSIONS

Among children with moderately-to-severely active Crohn's disease who received infliximab for 46 weeks in REACH and then for up to 3 additional years in the REACH OLE, infliximab was effective in maintaining clinical benefit and was generally well-tolerated.

Phase I trial of sargramostim in pediatric Crohn's disease

BACKGROUND

Improving granulocyte function may represent an effective therapy for Crohn's disease (CD). We performed a Phase I-2 trial of sargramostim (SRG) in children with CD.

METHODS

This was multicenter, open-label study in 6-16-year-old patients with moderate to severely active CD. Patients received either 4 or 6 microg/kg SRG subcutaneously daily for 8 weeks, with and without concomitant corticosteroids (CS). The primary endpoint was identification of a safe and tolerable dose in children. The secondary endpoint was establishment of the pharmacokinetics (PK). Efficacy, a tertiary endpoint, was measured by the Pediatric CD Activity Index (PCDAI). Response was defined as a decrease from baseline of > or =12.5 points and remission as absolute PCDAI of < or =10.

RESULTS

In all, 22 patients were enrolled: 12 and 10 received 4 and 6 mg/kg, respectively; 19 completed the course. Both doses were found to be safe and well tolerated. Mild injection-site reactions occurred in 90% of patients. Three patients required dose reductions due to elevated absolute neutrophil counts. Following 4 microg/kg the mean area under the curve (AUC) was 2.64 and 2.80 ngh/mL for the 6-11- and 12-16-year-old groups, respectively. The mean half-life (t(1/2)) was 1.22 and 1.59 hours, respectively. Following 6 microg/kg, the mean AUC was 5.01 ngh/mL for the 12-16-year-old group, a 1.8-fold increase. A total of 16/18 patients (88%) achieved remission or response.

CONCLUSIONS

Sargramostim at both 4 and 6 mg/kg was well tolerated. PK analysis suggested dose proportionality unaffected by CS exposure. Remission and response data are encouraging, but further trials are needed to assess efficacy.

Shortcomings of the inflammatory bowel disease Serology 7 panel

OBJECTIVE

The goal was to compare the predictive values of the Prometheus Inflammatory Bowel Disease (IBD) Serology 7 (IBD7) panel (Prometheus Laboratories, San Diego, CA) with the predictive values of routine blood tests in a population of children referred for initial evaluation of suspected IBD.

METHODS

Medical records of pediatric patients referred for evaluation of IBD for whom IBD7 testing was performed at Prometheus Laboratories between January 2006 and November 2008 were reviewed. Patients underwent diagnosis by pediatric gastroenterologists on the basis of clinical, radiologic, endoscopic, and pathologic evaluations.

RESULTS

A total of 394 records were identified. We excluded 90 records on the basis of age of >21 years, previous diagnosis of IBD, or unclear diagnosis. The prevalence of IBD in this cohort was 38%. The sensitivity, specificity, positive predictive value, negative predictive value, and kappa value for the serological panel were 67%, 76%, 63%, 79%, and 42%, respectively, compared with values for a combination of 3 abnormal routine laboratory test results of 72%, 94%, 85%, 79%, and 47%. The antiflagellin antibody assay, the newest assay added to the panel, had sensitivity of 50% and specificity of 53%. Repeat serological testing failed to produce consistent results for 4 of 10 patients.

CONCLUSION

Despite its recent inclusion of the antiflagellin assay, the IBD7 panel has lower predictive values than routine laboratory tests in pediatric screening for IBD.

Incidence of stricturing and penetrating complications of Crohn's disease diagnosed in pediatric patients

BACKGROUND

The development of disease complications is poorly characterized in pediatric patients with Crohn's disease (CD).

METHODS

We retrospectively determined the cumulative incidence of stricturing and penetrating complications of CD prior to first surgery utilizing data from 989 consecutively enrolled CD patients (age 0-17 years at diagnosis) collected between January 2000 and November 2003 and stored in the Pediatric IBD Consortium Registry.

RESULTS

Mean age at diagnosis was 11.5 +/- 3.8 (standard deviation) years. Median follow-up time was 2.8 years. Prior to first surgery, the cumulative incidence of stricturing or penetrating complications was 27% at 5 years and 38% at 10 years from the diagnosis of inflammatory bowel disease. The cumulative incidence of complicated disease was lowest in isolated colonic disease (P = 0.009). Penetrating complications that followed stricturing complications prior to first surgery occurred within 2 years of stricturing complications (cumulative incidence was 13% at 2 years from diagnosis of stricturing disease). Stricturing complications that followed penetrating complications prior to first surgery occurred within 8 years of penetrating complications (cumulative incidence was 26% at 8 years from diagnosis of penetrating complications).

CONCLUSIONS

Strictures, abscesses, and fistulas are common in pediatric CD. Earlier aggressive management may be indicated. Prospective study is required to identify genetic and serologic markers that predict a patient's risk for the development of complicated disease and to determine optimal treatment regimens.

Randomized controlled trial of feeding a concentrated formula to infants born to women infected by human immunodeficiency virus

OBJECTIVE

We tested the hypothesis that concentrated formula (CF) begun within the first 2 weeks of life increases growth in infants born to human immunodeficiency virus (HIV)-infected mothers.

MATERIALS AND METHODS

HIV-exposed infants from the United States, the Bahamas, and Brazil were randomized in a double-blind, controlled trial to receive either a CF (87 kcal/100 mL [26 kcal/oz]) or a standard formula (SF; 67 kcal/100 mL [20 kcal/oz]) for 8 weeks. This article presents results for infants who were not determined to be HIV infected based on testing at 4 weeks. Primary outcomes were safety, tolerability, and growth in weight and length.

RESULTS

Two thousand ninety-seven infants were enrolled, of whom 1998 were uninfected and had study formula dispensed. At weeks 4 and 8, uninfected infants receiving CF showed higher energy intake than those who were receiving SF (P < 0.001). By week 8, uninfected infants assigned to CF weighed more than infants receiving SF. There were no consistent differences in measures of tolerability, and rates of discontinuation or perceived formula intolerance were similar between treatment groups.

CONCLUSIONS

A CF is well tolerated and results in increased weight gain compared with SF. Until the HIV status of an infant is reliably determined, early introduction of a CF in HIV-exposed children may have beneficial effects on growth. The role of early nutritional intervention remains to be determined for individuals living in countries with endemic malnutrition for whom formula feeding is a viable option.

Folate concentrations in pediatric patients with newly diagnosed inflammatory bowel disease

BACKGROUND

Folate is postulated to protect against cell injury and long-term risk of cancer. Folate deficiency has been shown to be associated with inflammatory bowel disease (IBD). However, folate concentrations are poorly delineated in children with IBD.

OBJECTIVE

The objective was to compare folate concentrations between children with newly diagnosed IBD and healthy controls.

DESIGN

Red blood cell folate (RBCF) and whole-blood folate (WBF) concentrations were measured in 78 children (mean age: 12.8 +/- 2.7 y): 22 patients with newly diagnosed untreated Crohn disease, 11 patients with ulcerative colitis, 4 patients with indeterminate colitis, and 41 controls. Vitamin supplementation and dietary intakes determined by food-frequency questionnaire were recorded for 20 IBD patients and 28 controls.

RESULTS

RBCF concentrations were 19.4% lower in controls (587.0 +/- 148.6 ng/mL) than in patients (728.7 +/- 185.8 ng/mL; P = 0.0004), and WBF concentrations were 11.1% lower in controls (218.2 +/- 49.7 ng/mL) than in patients (245.3 +/- 59.1 ng/mL; P = 0.031). Total folate intake was 18.8% higher in controls (444.7 +/- 266.7 microg/d) than in IBD patients (361.1 +/- 230.6 microg/d), but this difference was not statistically significant (P = 0.264). Folate intakes were below the Recommended Dietary Allowance (200-400 microg/d), adjusted for age and sex, in 35.4% of study subjects.

CONCLUSIONS

In contrast with previous evidence of folate deficiency in adult IBD patients, our data indicate higher folate concentrations in children with newly diagnosed untreated IBD than in controls. This finding was unexpected, especially in light of the higher dietary folate intakes and hematocrit values in children without IBD. The influence of IBD therapy on folate metabolism and the long-term clinical implications of high RBCF and WBF concentrations at the time of IBD diagnosis should be explored further.

Development of extraintestinal manifestations in pediatric patients with inflammatory bowel disease

BACKGROUND

Extraintestinal manifestations (EIMs) in pediatric patients with inflammatory bowel disease (IBD) are poorly characterized. We examined the prevalence of EIMs at diagnosis, subsequent incidence, and risk factors for EIMs.

METHODS

Data for 1649 patients from the PediIBD Consortium Registry, diagnosed with IBD before 18 years of age (1007 [61%] with Crohn's disease, 471 [29%] with ulcerative colitis, and 171 [10%] with indeterminate colitis), were analyzed using logistic regression, Kaplan-Meier, log rank tests, and Cox models.

RESULTS

EIMs were reported prior to IBD diagnosis in 97 of 1649 patients (6%). Older children at diagnosis had higher rates compared with younger children, and arthritis (26%) and aphthous stomatitis (21%) were most common. Among the 1552 patients without EIM at diagnosis, 290 developed at least 1 EIM. Kaplan-Meier estimates of cumulative incidence were 9% at 1 year, 19% at 5 years, and 29% at 15 years after diagnosis. Incidence did not differ by IBD type (P = 0.20), age at diagnosis (P = 0.22), or race/ethnicity (P = 0.24). Arthritis (17%) and osteopenia/osteoporosis (15%) were the most common EIMs after IBD diagnosis.

CONCLUSIONS

In our large cohort of pediatric IBD patients, 6% had at least 1 EIM before diagnosis of IBD. At least 1 EIM will develop in 29% within 15 years of diagnosis. The incidence of EIMs both before and after diagnosis of IBD differs by type of EIM and may be slightly higher in girls, but is independent of the type of IBD, age at diagnosis, and race/ethnicity.

Inflammatory bowel disease in African American children compared with other racial/ethnic groups in a multicenter registry

BACKGROUND & AIMS

Few epidemiologic investigations characterize inflammatory bowel disease (IBD) in non-Caucasian children. Our study compared IBD characteristics between African Americans and non-African Americans enrolled in a multicenter pediatric IBD registry with endoscopic- and pathology-based diagnosis.

METHODS

The study retrieved data entered from January 2000 to October 2003 on children 1 to 17 years old, inclusive, followed by a consortium of academic and community US pediatric gastroenterology practices. Analyses examined racial/ethnic differences by comparing the proportions of African Americans and non-African Americans in the following categories: each diagnostic disease classification (any IBD, Crohn's disease, ulcerative colitis, indeterminate colitis); age group (<6 y, 6-12 y, or >12 y) at diagnosis or symptom onset; presence of extraintestinal manifestations, Z-scores for height and weight, immunomodulatory therapy, anatomic disease location, and abnormal hemoglobin, albumin, or sedimentation rate at diagnosis.

RESULTS

A total of 1406 patients had complete data, 138 (10%) of whom were African American. African Americans more often were older than 12 years of age at diagnosis (52% vs 37%; odds ratio [OR], 1.82; 95% confidence interval [95% CI], 1.28-2.59) and symptom onset (46% vs 30%; OR, 1.99; 95% CI, 1.40-2.84); had Crohn's disease (78% vs 59%; OR, 2.36; 95% CI, 1.56-3.58); and had a low hemoglobin level at diagnosis (39% vs 17%; OR, 3.15; 95% CI, 1.92-5.17).

CONCLUSIONS

IBD in African American children and adolescents presents more commonly with Crohn's disease and at older ages compared with non-African Americans. Racial/ethnic differences in the epidemiology of IBD, particularly Crohn's disease, among American youths require further investigation.

Growth hormone treatment for growth failure in pediatric patients with Crohn's disease

OBJECTIVE

To investigate the effect of human growth hormone (GH) injections on growth velocity in growth-impaired children with Crohn's disease (CD).

STUDY DESIGN

Ten children and adolescents (mean age, 12.6 +/- 4.5 years; 6 males) with CD and poor height growth were treated with open-label recombinant GH, 0.043 mg/kg/day administered via subcutaneous injection, for 1 year. Patients were retrospectively matched with untreated patients (3 comparisons per case) by race, age, sex, and baseline height. Primary endpoint was height velocity; secondary endpoints were disease activity, body composition, and bone density determined by dual-energy x-ray absorptiometry scan.

RESULTS

Mean height velocity increased by 5.33 +/- 3.40 (mean +/- standard deviation) cm/year in the GH-treated patients during the year of GH treatment, compared with 0.96 +/- 3.52 cm/year in the comparison group (P = .03). Height z-score increased by 0.76 +/- 0.38 in the treated group, compared with 0.16 +/- 0.40 in the comparison group (P < .01), and weight z-score increased by 0.81 +/- 0.89 in the treated group, compared with 0.00 +/- 0.57 in the comparison group (P < .01). Bone density revealed an increase of 0.31 +/- 0.33 in the lumbar spine z-score (P = .03 vs baseline).

CONCLUSIONS

GH treatment increases height velocity and may enhance bone mineralization in children with CD. A randomized controlled trial in a large cohort of children is needed to evaluate the ultimate impact of GH treatment.

Presentation and disease course in early- compared to later-onset pediatric Crohn's disease

BACKGROUND

The relationship between the age at diagnosis and disease course is poorly defined in children with Crohn's disease (CD). We examined the presentation and course of disease in patients 0-5 compared to 6-17 yr of age at diagnosis.

METHODS

We analyzed uniform data from 989 consecutive CD patients collected between January 2000 and November 2003, and stored in the Pediatric IBD Consortium Registry. The statistical tests account for the length of follow-up of each patient.

RESULTS

In total, 98 patients (9.9%) were of 0-5 yr of age at diagnosis. The mean follow-up time was 5.6 +/- 5.0 yr in the younger group and 3.3 +/- 2.8 yr in the older group (P < 0.001). Race/ethnicity differed by the age group (P= 0.015); a larger proportion of the younger group was Asian/Pacific Islander or Hispanic, and a larger proportion of the older group was African American. The initial classification as ulcerative colitis or indeterminate colitis was more common among the 0-5 yr of age group (P < 0.001). The 6-17 yr of age patients presented with more abdominal pain (P < 0.001), weight loss (P= 0.001), or fever (P= 0.07), while the 0-5 yr of age patients presented with more rectal bleeding (P= 0.008). The 6-17 yr of age patients were more likely to be treated with antibiotics (P < 0.001), 6-mercaptopurine/azathioprine (P < 0.001), infliximab (P= 0.001), or corticosteroids (P= 0.0006). The 6-17 yr of age patients had a higher cumulative incidence of treatment with 5-aminosalicylates (P= 0.009) or methotrexate (P= 0.04). The risk for developing an abscess (P= 0.001), a fistula (P= 0.02), a stricture (P= 0.05), or a perianal fissure (P= 0.06) was greater in the 6-17 yr of age patients.

CONCLUSIONS

The 6-17 yr of age patients with CD appear to have a more complicated disease course compared to 0-5 yr of age children. The 0-5 yr of age group may represent a unique disease phenotype and benefit from different approaches to management. Long-term prospective studies are required to validate these findings.

Reduced intracellular T-helper 1 interferon-gamma in blood of newly diagnosed children with Crohn's disease and age-related changes in Th1/Th2 cytokine profiles

Abnormal cytokine production by T-helper 1 (Th1)/T-helper 2 (Th2) lymphocytes has been implicated in the pathogenesis of inflammatory bowel disease (IBD). Few studies have examined Th1/Th2 cytokine status in pediatric IBD patients, and results have been inconsistent. We used flow cytometric detection of intracellular IFN-gamma/IL-4 cytokine production to investigate CD4+, Th1, and Th2 cells in the peripheral blood of children with untreated, newly diagnosed Crohn's disease (CD) (n = 23) and matched healthy controls (n = 49). Th1 cytokine levels were lower in CD patients compared with controls (p = 0.006) and strongly correlated with levels of albumin and hematocrit (r = 0.51, p = 0.007 and r = 0.35, p = 0.052, respectively). An age-dependent increase in Th1 cells was observed (p < 0.0005); however, no correlation was found between age, clinical end points, %CD4+, or Th2 cell numbers. In conclusion, the Th1 cytokine levels in blood are lower in early onset CD patients than in healthy children and are directly associated with disease-related clinical parameters. In future studies of pediatric IBD patients, it will be critical to consider the effect of age and disease progression on cytokine status in intestinal mucosa and peripheral blood.

Gender differences in presentation and course of disease in pediatric patients with Crohn disease

OBJECTIVE

The objective of this study was to determine gender differences in pediatric patients with Crohn disease.

METHODS

We conducted a retrospective cohort study of 989 consecutive pediatric patients (566 boys, 423 girls) who had Crohn disease (aged 0 to 17 years at diagnosis) by using the Pediatric IBD Consortium Registry. Uniform data were analyzed to compare the presentation and course of disease according to gender.

RESULTS

Median follow-up time was 2.8 years. Mean +/- SD age at diagnosis of inflammatory bowel disease (11.5 +/- 3.8 years) did not differ by gender. Compared with boys, girls had a higher prevalence of mouth sores at symptom onset and a higher prevalence of hypoalbuminemia at the time of diagnosis. Location of disease did not differ by gender. A higher proportion of girls had abnormal anti-outer membrane porin of Escherichia coli levels compared with boys. Girls were at increased risk for erythema nodosum/pyoderma gangrenosum and decreased risk for growth failure compared with boys.

CONCLUSIONS

Girls appear to have an overall more severe course of disease; however, boys are at increased risk for developing growth failure. Disease course and the impact of disease severity on growth according to gender in pediatric Crohn disease require prospective study.

Knowledge, attitudes and practice styles of North American pediatricians regarding gastroesophageal reflux disease

BACKGROUND

The North American Society for Pediatric Gastroenterology, Hepatology and Nutrition launched a provider and public education campaign in 2002 to raise awareness of gastroesophageal reflux disease (GERD). To determine the effectiveness of campaign messages, we conducted a knowledge, attitudes, and practice styles (KAPS) survey of pediatric providers. Understanding the spectrum of management styles of GERD in children is critical to achieve better health outcomes and reduce health care costs.

MATERIALS AND METHODS

The KAPS questionnaire was administered to 6000 randomly selected members of the American Academy of Pediatrics.

RESULTS

A total of 1245 members responded; 82% worked in a primary care setting and 18% in subspecialty practices. Overall, 66% of the members order diagnostic testing in routine practice, 54% start testing for GERD in neonates, and 38% start testing after 1 month of age. The most common tests ordered were barium esophagram (45%) and esophageal pH monitoring (37%). GERD treatment with acid suppression before ordering diagnostic testing was a choice of 82% of the respondents. However, 19% believed acid suppression was best achieved by H2 blockers. If acid suppression was indicated, then only 36% followed guideline recommendations for therapy duration and 52% followed guideline recommendations for dosing. Antireflux surgery was recommended only as a last resort by 92%. Overall, 69% of providers believed the amount of GERD-related information available was not enough. Respondents who were not aware of available GERD practice guidelines ranged from 74% to 92%.

CONCLUSIONS

Pediatric providers appear to frequently order diagnostic testing and treatment for GERD, yet knowledge about evidence-based GERD management among this random sample appeared limited. Moreover, a significant number of providers were not aware of different guideline publications.

Pharmacokinetics and pharmacodynamics of lansoprazole in children 13 to 24 months old with gastroesophageal reflux disease

OBJECTIVES

To evaluate the pharmacokinetics and pharmacodynamics of lansoprazole in children between 13 and 24 months of age with gastroesophageal reflux disease (GERD).

METHODS

From the population of 66 children with symptomatic GERD, erosive esophagitis (> or = grade 2) or esophageal pH < 4 for > 4.2% of the 24-h period who participated in a phase I/II, open-label, multicenter (11 sites) US study, a subanalysis of 8 toddlers between 13 and 24 months of age was performed. All children were treated, based on body weight, with lansoprazole 15 mg once daily for 8 to 12 weeks. If a child were still symptomatic after 2 weeks of treatment, then the dose of lansoprazole could be increased to twice daily at the discretion of the investigator. Pharmacokinetic parameters were assessed at day 5. Twenty-four-hour median intragastric pH and the percentage of time intragastric pH > 3 or > 4 were assessed at baseline and at day 5 of treatment. Symptom response was assessed by investigator interview and daily diary. Safety was monitored by physical examinations including vital signs, adverse event assessments and laboratory evaluations.

RESULTS

Pharmacokinetic analysis of 5 children found a mean time to reach maximum concentration of 1.4 h, maximal plasma concentrations of 894 ng/mL, area under the concentration time curve of 1906 ng * h/mL and a half-life of 0.66 h. Significant (P < or = 0.027) increases from baseline to day 5 were observed in mean 24-h intragastric pH (2.76-3.52) and the percentages of time pH were > 3 (29.46%-55.36%) and pH was > 4 (16.96%-40.77%). Six of the 8 children had improvement in their overall GERD symptom severity on the basis of investigator assessment, and a reduction was seen in the percentage of days with moderate, severe or very severe GERD symptoms compared with baseline. The dosage of lansoprazole was increased in 3 of the 8 children. Median fasting serum gastrin level increased from 65.0 pg/mL at baseline to 136.5 pg/mL at the final visit. Treatment-related events were mild constipation (1 subject) and mild diarrhea (1 subject).

CONCLUSIONS

Although larger studies are needed to confirm these results, lansoprazole displays pharmacokinetic and pharmacodynamic parameters in children between 13 and 24 months of age that are similar to those results observed in older children as well as adults.

Risk factors for initial surgery in pediatric patients with Crohn's disease

BACKGROUND & AIMS

The cumulative incidence of surgery ranges from 40%-70% at 10 years from the time of diagnosis of Crohn's disease in adults. We retrospectively determined the cumulative incidence of and risk factors for surgery (intestinal resection) in pediatric patients with Crohn's disease.

METHODS

Uniform data from 989 consecutive Crohn's disease patients (age 0-17 years at diagnosis), collected from 6 different pediatric centers between January 2000 and November 2003 and stored in the Pediatric IBD Consortium Registry, were analyzed.

RESULTS

Median follow-up time was 2.8 years (range, 1 day to 16.7 years). One hundred twenty-eight patients underwent surgery. Kaplan-Meier survival estimates of the cumulative incidence of surgery were 17% at 5 years and 28% at 10 years from the diagnosis of inflammatory bowel disease. Univariate Cox proportional hazards models showed leukocytosis (2.85 [hazard ratio]; P = .02), hypoalbuminemia (3.41; P = .05), and anti-Saccharomyces cerevisiae antibody (ASCA) positivity (3.43; P = .05) were associated with increased risk for surgery. Multivariate Cox models showed female gender (1.49; P = .03), initial diagnosis of ulcerative colitis (3.63; P < .0001), poor growth at presentation (2.16; P = .007), and abscess (1.90; P = .009), fistula (2.30; P = .0005), or stricture (3.41; P < .0001) development were associated with increased risk for surgery. Age 3-5 years (0.26; P = .01) or 6-12 years (0.62; P = .01) at diagnosis, fever at presentation (0.50; P = .03), and treatment with infliximab (0.36; P = .0005) or 5-aminosalicylic acid (0.44; P < .0001) were associated with decreased risk for surgery.

CONCLUSIONS

Risk stratification during the course of Crohn's disease in pediatric patients will help to guide therapy that may improve the natural history of disease and decrease the need for surgery.

Age-specific questionnaires distinguish GERD symptom frequency and severity in infants and young children: development and initial validation

Two gastroesophageal reflux disease (GERD) symptom questionnaires were developed and tested prospectively in a pilot study conducted in infants (1 through 11 months) and young children (1 through 4 years) with and without a clinical diagnosis of GERD. A pediatric gastroenterologist made the clinical diagnosis of GERD. Parents or guardians at 4 study sites completed the questionnaires, providing information on the frequency and severity of symptoms appropriate to the 2 age cohorts. In infants, symptoms assessed were back arching, choking or gagging, hiccups, irritability, refusal to feed and vomiting or regurgitation. In young children, symptoms assessed were abdominal pain, burping or belching, choking when eating, difficulty swallowing, refusal to eat and vomiting or regurgitation. Respondents were asked to describe additional symptoms. Symptom frequency was the number of occurrences of each symptom in the 7 days before completion of the questionnaire. Symptom severity was rated from 1 (not at all severe) to 7 (most severe). An individual symptom score was calculated as the product of symptom frequency and severity scores. The composite symptom score was the sum of the individual symptom scores. The mean composite symptom and individual symptom scores were higher in infants (P<0.001 and P<0.05, respectively) and young children (P<0.001 and P<0.05, respectively) with GERD than controls. Vomiting/regurgitation was particularly prevalent in infants with GERD (90%). Both groups with GERD were more likely to experience greater severity of symptoms. We found the GERD Symptom Questionnaire useful in distinguishing infants and young children with symptomatic GERD from healthy children.

Premedication and infusion reactions with infliximab: results from a pediatric inflammatory bowel disease consortium

BACKGROUND

Infusion reactions (IRs) are the most common adverse events associated with the use of infliximab for inflammatory bowel disease (IBD). Antipyretics, antihistamines, and corticosteroids have been used to prevent the development of IRs, but their efficacy is not known. We studied the proportion of pediatric patients receiving infliximab for IBD that developed IRs and the potential effects of premedication on IR.

METHODS

Uniformly collected data from a cohort of pediatric patients with IBD enrolled between January 2000 and May 2003 at 6 pediatric centers were analyzed. Data were retrospectively reviewed and analyzed.

RESULTS

A total of 1652 infusions given to 243 patients in 6 centers was analyzed. Overall, 60 IRs were recorded in 40 patients (3.6% of infusions, 16.5% of patients). Thirty-three of 243 patients received premedication before the first IR (group 1). Two hundred ten patients did not receive premedication until the development of IRs, if at all (group 2). IRs were more common among patients in group 1 than in group 2 (12/33 versus 28/210, P < 0.01). Of the 28 patients in group 2 with IRs, 10 began receiving premedication with each subsequent infusion, 12 continued without premedications, and 6 had no further infusions recorded. Two of 10 who began receiving premedication had a subsequent IR versus 6 of 12 who did not receive premedication (P = 0.15).

CONCLUSIONS

IRs occur in a small proportion of infusions among pediatric patients receiving infliximab for IBD. Premedication does not seem to prevent the development of IRs; however, once an IR has occurred, premedication may be indicated to prevent subsequent IRs.

Children with early-onset inflammatory bowel disease (IBD): analysis of a pediatric IBD consortium registry

OBJECTIVE

To determine the characteristics of inflammatory bowel disease (IBD) in young patients.

STUDY DESIGN

Uniform data were collected from a cohort of patients with IBD who were enrolled from January 2000 to November 2002 at six pediatric centers (Pediatric IBD Consortium).

RESULTS

Of 1370 children in the registry, the mean age at IBD diagnosis was 10.3 +/- 4.4 years; 54% were male, and 86% were white. Diagnosis was confirmed in 87 (6.1%) under 3 years of age, 211 (15.4%) before 6 years, 654 (47.7%) at 6 to 12 years, and 505 (36.9%) at 13 to 17 years. More than 63% of children younger than 8 years of age had isolated colonic disease, whether Crohn disease, ulcerative colitis (UC), or indeterminate colitis. Conversely, only 35% of those 8 years of age or older had isolated colonic disease ( P < .0001). Overall, 29% had one or more family members with IBD. The subgroup of children younger than 3 years of age with UC had the highest prevalence of first-degree relatives with IBD (44%).

CONCLUSIONS

This demographically diverse pediatric IBD cohort revealed age-related variation in the distribution of IBD phenotype, with a high prevalence of isolated colonic disease in young children. Positive family history was especially common in young patients with UC.

CDP571, a humanized anti-tumor necrosis factor-alpha monoclonal antibody in pediatric Crohn's disease

OBJECTIVES

The objectives of this study were to evaluate the safety, pharmacokinetics, and immunogenicity of CDP571 in pediatric patients with Crohn's disease.

METHODS

A single dose of CDP571, 10 mg/kg, was administered by infusion to pediatric patients (aged 6-17 years) with Crohn's disease in a 12-week open-label study. Adverse events were monitored during infusion and throughout the study. Plasma concentrations of CDP571 and standard clinical and laboratory values were assessed. Changes in disease activity were monitored using the Pediatric Crohn's Disease Activity Index (PCDAI).

RESULTS

Twenty patients were enrolled and stratified by age: 6 to 13 (n = 9) and 14 to 17 years (n = 11). Fourteen patients experienced adverse events, which were mainly mild or moderate in intensity. The plasma concentration profile was consistent with a half-life of approximately 2 weeks. At Week 4, 4 patients in the 6- to 13-year-old group and 2 patients in the 14- to 17-year-old group had detectable anti-CDP571 antibodies. By Week 2, 7 patients in the 6- to 13-year-old group and 6 patients in the 14- to 17-year-old group had responded to treatment (reduction in PCDAI score >10 points).

CONCLUSION

In conclusion, CDP571 was well tolerated among pediatric patients with Crohn's disease.