Early Serum Infliximab Levels in Pediatric Ulcerative Colitis.

Background: Data on serum infliximab concentrations during induction in pediatric ulcerative colitis are limited. The study aim is to evaluate the relationship between serum infliximab concentrations during induction and short-term clinical remission in children with ulcerative colitis. Methods: We carried out a prospective, multi-center cohort study in pediatric patients with ulcerative colitis. Serum infliximab concentrations were collected at peak dose #1, week 1, trough pre-dose #2, and trough pre-dose #3. Infliximab dosing was left to investigator discretion. Clinical remission was defined by pediatric ulcerative colitis activity index <10 at week 8. Results: Twenty-four of thirty-four subjects (71%) achieved clinical remission at week 8. The median infliximab concentrations were 33.0 µg/mL (interquartile range: 26.5-52.1 µg/mL) pre-dose #2 and 22.5 µg/mL (interquartile range:15.9-32.3 µg/mL) pre-dose #3. Trough pre-dose #2 infliximab concentration yielded area under receiver operator characteristic curve 0.7, 95% CI: 0.5-0.9 in predicting week 8 clinical remission; a cut-off of 33.0 µg/mL yielded 62.5% sensitivity, 66.7% specificity. Trough pre-dose #3 infliximab concentrations were lower for subjects <10 years compared to ≥ 10 years [median 15.9 µg/mL, interquartile range (IQR) 8.5-21.8 µg/mL vs. 27.7 µg/mL, IQR 17.2-46.7 µg/mL, p = 0.01] and correlated with baseline weight (Spearman's rank correlation coefficient 0.45, p = 0.01). The median half-life following first IFX dose was 6.04 days (IQR 5.3-7.9 days). Conclusions: Infliximab concentrations ≥33 µg/mL prior to the second dose were associated with week 8 clinical remission. As young age and low body weight impact infliximab concentration, prospective studies with proactive adjustment in pediatric patients with ulcerative colitis should be carried out. Clinicians caring for children with UC should diligently adjust and monitor infliximab to optimize response.

Serologic Status of Routine Childhood Vaccines, Cytomegalovirus, and Epstein-Barr Virus in Children With Inflammatory Bowel Disease.

BACKGROUND: Data on the serologic status of childhood vaccines, cytomegalovirus (CMV) and Epstein-Barr virus (EBV), are limited in inflammatory bowel disease (IBD). Therefore, we evaluated vaccine coverage and seroprotection, along with CMV and EBV seropositivity, in pediatric IBD. METHODS: In a cross-sectional study, demographic data, IBD history, vaccine records, and serum for antibodies against measles, mumps, rubella, diphtheria, tetanus, varicella, hepatitis B (HBV), CMV, and EBV were collected from children with IBD. We evaluated potential factors associated with serologic status. RESULTS: Of 156 subjects, vaccine coverage was up to date for age in 93.5% for measles, mumps, rubella, 95.6% for diphtheria, tetanus, pertussis, polio, hemophilus influenza B, 75.8% for HBV, and 93.5% for varicella, including past infection and vaccination. Seroprotection was present in 65.8% for measles, 60.5% for mumps, 79.1% for rubella, 79.5% for diphtheria, 80.8% for tetanus, 70.5% for varicella, and 62.8% for HBV of subjects. Older age at diagnosis was associated with seroprotection among subjects with complete HBV (odds ratio [OR], 1.20; 95% confidence interval [CI], 1.03-1.39) and rubella series (OR, 1.18; 95% CI, 1.02-1.37). Older age at serum collection was associated with seroprotection among subjects with prior varicella vaccination or infection (OR, 1.69; 95% CI, 1.33-2.15). Only 25.2% and 37.8% demonstrated seropositivity to CMV and EBV, respectively. Among subjects on immunosuppressive medications, 75.3% and 62.4% were seronegative for CMV and EBV, respectively. CONCLUSIONS: Children with IBD have low serologic protection to childhood vaccines in spite of high vaccine coverage and universal vaccinations. Children with IBD, including a large proportion on immunosuppressive medications, have low seropositivity to CMV and EBV.

Long-term Outcomes of Infliximab Use for Pediatric Crohn Disease: A Canadian Multicenter Clinical Practice Experience.

BACKGROUND: Data on long-term real-world outcomes of infliximab in pediatric Crohn disease are limited. AIM: The aim of the study was to evaluate infliximab optimization and durability in children with Crohn disease. METHODS: We performed a retrospective review of children with Crohn disease who started infliximab from January 2008 to December 2012 in 4 Canadian tertiary care centers. A priori factors associated with optimization and discontinuation from loss of response were evaluated using logistic regression and Cox proportional hazards model, respectively. RESULTS: One hundred eighty children (54.4% boys) started infliximab; all completed induction. Median age at infliximab start was 14.3 years (Q1, Q3: 12.8, 15.9 years) and median time from diagnosis to infliximab start was 1.5 years (Q1, Q3: 0.6, 3.5 years). At last follow-up, 87.1% were maintained on infliximab (median duration follow-up 85.9 weeks [Q1, Q3: 43.8, 138.8 weeks]). Infliximab optimization occurred in 57.3% (dose escalation 15.2%, interval shortening 3.9%, both 38.2%), primarily due to loss of response. Younger age at diagnosis (<10 years old) and nonstricturing, nonpenetrating behavior were associated with optimization (odds ratio 6.5, 95% confidence interval [CI] 2.0-21.1 and odds ratio 2.1, 95% CI 1.0-4.2, respectively). The 1- and 2-year durability of infliximab (percentage in follow-up who were continuing on infliximab) were 95.5% (95% CI 90.4-98.3) and 91.0% (95% CI 82.4-96.3), respectively. Annual discontinuation due to loss of response occurred at 3.2% per year (95% CI 1.1-5.2). CONCLUSIONS: Children with Crohn disease maintain a durable response to infliximab. Optimization occurs frequently and allows for continued use. Younger age at diagnosis and nonstricturing, nonpenetrating behavior are associated with increased need for infliximab optimization.

Immunogenicity of Influenza Vaccine for Patients with Inflammatory Bowel Disease on Maintenance Infliximab Therapy: A Randomized Trial.

BACKGROUND: In patients with inflammatory bowel disease (IBD) on infliximab, data are limited on immune response to influenza vaccine and the impact of vaccine timing. The study aims were to evaluate immune responses to the influenza vaccine in IBD patients on infliximab and the impact of vaccine timing on immune responses. METHODS: In this randomized study, 137 subjects with IBD on maintenance infliximab therapy were allocated to receive the 2012/2013 inactivated influenza vaccine at the time of infliximab infusion (n = 69) or midway between infusions (n = 68). Serum was collected before and after vaccination for hemagglutination inhibition titers. Serologic protection was defined by postvaccine titer of ≥1:40. RESULTS: Comparing subjects vaccinated at the time of infliximab with those vaccinated midway, serologic protection was achieved in 67% versus 66% to H1N1 (P = 0.8), in 43% versus 49% to H3N2 (P = 0.5), and in 69% versus 79% to influenza B (P = 0.2). Although solicited adverse events were common (60%), no subject experienced a serious adverse event requiring additional medical attention. Only 6% of subjects had a clinically significant increase in disease activity score, not impacted by vaccine timing. CONCLUSIONS: Serologic protection to influenza vaccine is achieved in only approximately 45% to 80% of IBD patients on maintenance infliximab therapy varying by antigen. Yet, importantly, vaccine timing relative to infliximab infusion does not affect the achievement of serologic protection, and the influenza vaccine is well tolerated. Therefore, influenza vaccination at any point during infliximab scheduling is recommended for patients with IBD and opportunities to broaden the availability and convenience of influenza vaccine to optimize coverage should be explored.

Rising post-colectomy complications in children with ulcerative colitis despite stable colectomy rates in United States.

BACKGROUND AND AIMS: In children with ulcerative colitis, data on temporal colectomy trends and in-hospital post-colectomy complications are limited. Thus, we evaluated time trends in colectomy rates and post-colectomy complications in children with ulcerative colitis. METHODS: We identified all children (≤18years) with a diagnosis code of ulcerative colitis (ICD-9: 556.X) and a procedure code of colectomy (ICD-9: 45.8 and 45.7) in the Kids' Inpatient Database for 1997, 2000, 2003, 2006 and 2009. The incidence of colectomies for pediatric ulcerative colitis was calculated and Poisson regression analysis was performed to evaluate the change in colectomy rates. In-hospital postoperative complication rates were assessed and predictors for postoperative complications were evaluated using multivariate logistic regression. RESULTS: The annual colectomy rate in pediatric ulcerative colitis was 0.43 per 100,000person-years, which was stable throughout the study period (P>.05). Postoperative complications were experienced in 25%, with gastrointestinal (13%) and infectious (9.3%) being the most common. Postoperative complication rates increased significantly by an annual rate of 1.1% from 1997 to 2009 (P=.01). However, other independent predictors of postoperative complications were not identified. Patients with postoperative complications had significantly longer median length of stay (14.3days vs 8.2days; P<.001) and higher median hospital charges per patient (US $81,567 vs US $55,461; P<.001) compared to those without complications. CONCLUSION: Colectomy rates across the United States in children with ulcerative colitis have remained stable between 1997 and 2009; however, in-hospital postoperative complication rates have increased.

Nationwide temporal trends in incidence of hospitalization and surgical intestinal resection in pediatric inflammatory bowel diseases in the United States from 1997 to 2009.

BACKGROUND: Data are limited on temporal trends in outcomes of hospitalization and surgery in pediatric Crohn's disease (CD) and ulcerative colitis (UC). Thus, we evaluated the U.S. nationwide temporal trends for incidence of hospitalization and intestinal resection along with associated resource utilization. METHODS: We used the Kids' Inpatient Database (1997, 2000, 2003, 2006, and 2009) to identify all admissions for children aged 18 years or younger with a primary CD (International Classification of Diseases, Ninth Revision [ICD-9]: 555.X) or UC (ICD-9: 556.X) diagnosis or a secondary CD or UC diagnosis and procedural code of intestinal resection. Poisson regression analysis was performed to evaluate time trends in the incidence of hospitalization, intestinal resection, and hospital resource utilization. RESULTS: The annual incidence of hospitalization was 5.7 and 3.5 per 100,000 children for CD and UC, respectively, with significant increases over time for CD (annual percent increase [API], 3.8%; 95% confidence interval [CI], 3.0%-4.5%) and UC (API, 4.5%; 95% CI, 4.3%-4.7%). Median hospital days per hospitalization for CD and UC remained stable, whereas median charge per hospitalization increased for CD (API, 4.1%; 95% CI, 2.6%-5.6%) and UC (API, 4.7%; 95% CI, 3.5%-5.9%). The annual incidence of intestinal resection remained stable for UC at 0.6 per 100,000 children but climbed for CD (API, 2.1%; 95% CI, 0.1-4.2). CONCLUSIONS: The annual incidence of hospitalization is climbing in pediatric inflammatory bowel diseases, accompanied by rising intestinal resection rates for CD and stable colectomy rates for UC. With escalating resource utilization, the economic and health burden of pediatric inflammatory bowel diseases is substantial.

Multidimensional prognostic risk assessment identifies association between IL12B variation and surgery in Crohn's disease.

BACKGROUND: The ability to identify patients with Crohn's disease (CD) at highest risk of surgery would be invaluable in guiding therapy. Genome-wide association studies have identified multiple IBD loci with unknown phenotypic consequences. The aims of this study were to: (1) identify associations between known and novel CD loci with early resective CD surgery and (2) develop the best predictive model for time to surgery using a combination of phenotypic, serologic, and genetic variables. METHODS: Genotyping was performed on 1,115 subjects using Illumina-based genome-wide technology. Univariate and multivariate analyses tested genetic associations with need for surgery within 5 years. Analyses were performed by testing known CD loci (n = 71) and by performing a genome-wide association study. Time to surgery was analyzed using Cox regression modeling. Clinical and serologic variables were included along with genotype to build predictive models for time to surgery. RESULTS: Surgery occurred within 5 years in 239 subjects at a median time of 12 months. Three CD susceptibility loci were independently associated with surgery within 5 years (IL12B, IL23R, and C11orf30). Genome-wide association identified novel putative loci associated with early surgery: 7q21 (CACNA2D1) and 9q34 (RXRA, COL5A1). The most predictive models of time to surgery included genetic and clinical risk factors. More than a 20% difference in frequency of progression to surgery was seen between the lowest and highest risk groups. CONCLUSIONS: Progression to surgery is faster in patients with CD with both genetic and clinical risk factors. IL12B is independently associated with need and time to early surgery in CD patients and justifies the investigation of novel and existing therapies that affect this pathway.

Immunization history of children with inflammatory bowel disease.

BACKGROUND: Protection against vaccine-preventable diseases is important in children with inflammatory bowel disease (IBD) due to frequent immunosuppressive therapy use. The chronic relapsing nature and treatment regimen of IBD may necessitate modified timing of immunizations. OBJECTIVE: To evaluate the completeness of immunizations in children with IBD. METHODS: Immunization records of all children with IBD followed at the Alberta Children's Hospital (Calgary, Alberta) were reviewed. For children with incomplete immunization according to the province of Alberta schedule, the reasons for such were clarified. Demographic data and age at diagnosis were also collected. RESULTS: Immunization records were obtained from 145 (79%) children with IBD. Fifteen children had incomplete routine childhood immunizations, including two with no previous immunizations. The most common incomplete immunizations included hepatitis B (n=9), diphtheria, tetanus, acellular pertussis at 14 to 16 years of age (n=7), and diphtheria, tetanus, acellular pertussis, inactivated polio at four to six years of age (n=6). The reasons for incomplete immunization included use of immunosuppressive therapy at time of scheduled immunization; IBD-related symptoms at time of scheduled immunization; parental refusal; recent move from elsewhere with different immunization schedule; unawareness of routine immunization; and needle phobia. CONCLUSIONS: Although the majority of children with IBD had complete childhood immunizations, suboptimal immunizations were present in 10%. With increasing use of immunosuppressive therapy in IBD, physicians caring for children with IBD must periodically evaluate immunization status and ensure the completeness of childhood immunizations.

Postoperative complications following colectomy for ulcerative colitis in children.

BACKGROUND AND AIMS: Colectomy rates for ulcerative colitis (UC) and data on postcolectomy complications in children are limited. Thus, we assessed colectomy rates, early postcolectomy complications, and clinical predictors in children with UC undergoing a colectomy. METHODS: Children (18 years old or older) with UC who underwent colectomy from 1983 to 2009 were identified (n=30). All of the medical charts were reviewed. The diagnostic accuracy of International Classification of Diseases codes for UC and colectomy were validated. The primary outcome was postoperative complications defined as Clavien-Dindo classification grade II or higher. The yearly incidence of colectomies for pediatric UC was calculated and temporal trends were evaluated. RESULTS: The sensitivity and positive predictive value of UC and colectomy International Classification of Diseases codes were 96% and 100%, respectively. The median ages at UC diagnosis and colectomy were 10.9 and 12.1 years, respectively. All of the children had pancolitis and 63% underwent emergent colectomy. Postoperatively, 33% experienced at least 1 complication. Patients with emergent colectomy were more likely to have a postoperative complication compared with patients with elective colectomy (90% vs 50%; P=0.03). For emergent colectomy, postoperative complications were associated with a disease flare of ≥2 weeks before admission (60% vs 0%; P=0.03) and >2 weeks from admission to colectomy (78% vs 22%; P=0.04). The average annual rate of pediatric colectomy was 0.059/100,000 person-years and stable from 1983 to 2009 (P>0.05). CONCLUSIONS: Colectomy UC was uncommon and rates have remained stable. Postcolectomy complications were common, especially in patients undergoing emergent colectomy. Optimizing timing of colectomy may reduce postoperative complications.

Immunogenicity and safety of influenza vaccination in children with inflammatory bowel disease.

BACKGROUND: Protection against vaccine-preventable diseases is important in inflammatory bowel disease (IBD) because of increased susceptibility and severity of infection with immunosuppressive therapy. However, immunosuppressive therapy may affect vaccine response. This study aimed to evaluate immunogenicity and safety of influenza vaccination in children with IBD. METHODS: In this prospective cohort study, 60 children with IBD and 53 healthy controls had serum collected for preimmunization hemagglutination-inhibition antibody titers to the 2008 inactivated influenza vaccine components. Three to 5 weeks following vaccine [A/Brisbane/10/2007(H3N2), A/Brisbane/59/2007(H1N1), B/Florida/4/2006] administration, all participants had serum collected for postimmunization titers. A 4-fold or greater increase between pre- and postimmunization titers indicated an immunogenic response; a postimmunization titer ≥1:40 indicated serologic protection. Children with IBD were classified into immunosuppression status by therapy. RESULTS: Seventy percent, 72%, and 53% of children with IBD mounted an immunogenic response to H3N2, H1N1, and influenza B components, respectively. Among children with IBD, serologic protection was achieved in 95%, 98%, and 85% to H3N2, H1N1, and influenza B components, respectively. For influenza B, children with IBD were less likely to mount an immunogenic response compared to controls (53% versus 81%, P = 0.0009), and immunosuppressed children with IBD were less likely to achieve serologic protection compared to nonimmunosuppressed children with IBD (79% versus 100%, P = 0.02). The majority (98%) tolerated the vaccine. CONCLUSIONS: Although children with IBD achieve appropriate immunogenicity to influenza A, immunogenicity to influenza B appears to be diminished, especially with immunosuppressive therapy.

Association of Mycobacterium avium subspecies paratuberculosis with Crohn Disease in pediatric patients.

OBJECTIVES: The aim of the present study was to determine the prevalence of Mycobacterium avium subsp paratuberculosis (MAP) DNA in intestinal biopsies from pediatric patients with granulomatous Crohn disease (CD) or ulcerative colitis (UC), and matched control subjects without inflammatory bowel disease (IBD). PATIENTS AND METHODS: DNA was extracted from formalin-fixed paraffin-embedded colonic and ileal biopsies from patients with CD (n = 22) or UC (n = 20), and from controls without IBD (n = 21). IS900 nested polymerase chain reaction was performed in triplicate to determine the presence of MAP-specific DNA. RESULTS: In mucosal biopsies from terminal ileum, IS900 amplicons were detected in 1 of 19 (5.2%) control subjects, 1 of 20 (5%) patients with UC, and 7 of 20 (35%) patients with CD (P < 0.05 vs controls, odds ratio 9.6). In colonic biopsies, IS900 amplicons were detected in 0 of 19 control subjects, 1 of 19 (5.2%) patients with UC, and 5 of 19 (26.3%) patients with CD (P < 0.05 vs controls, odds ratio 14.8). In patients with CD, there was no correlation between disease activity and the presence of IS900. CONCLUSIONS: Our technique enabled sensitive and specific detection of MAP DNA in archival endoscopic biopsy specimens. Although MAP-specific DNA can be detected in about 5% of intestinal biopsies from children with UC or controls without IBD, its presence was significantly associated with pediatric granulomatous CD, being particularly prevalent in ileal tissue. This easily defined clinical subset of patients may be useful for additional studies to determine the role of MAP in CD.

Real-time tool to display the predicted disease course and treatment response for children with Crohn's disease.

BACKGROUND: Immunomodulators and biologics are effective treatments for children with Crohn's disease (CD). The challenge of communicating the anticipated disease course with and without therapy to patients and parents is a barrier to the timely use of these agents. The aim of this project was to develop a tool to graphically display the predicted risks of CD and expected benefits of therapy. METHODS: Using prospectively collected data from 796 pediatric CD patients we developed a model using system dynamics analysis (SDA). The primary model outcome is the probability of developing a CD-related complication. Input variables include patient and disease characteristics, magnitude of serologic immune responses expressed as the quartile sum score (QSS), and exposure to medical treatments. RESULTS: Multivariate Cox proportional analyses show variables contributing a significant increase in the hazard ratio (HR) for a disease complication include female gender, older age at diagnosis, small bowel or perianal disease, and a higher QSS. As QSS increases, the HR for early use of corticosteroids increases, in contrast to a decreasing HR with early use of immunomodulators, early or late biologics, and early combination therapy. The concordance index for the model is 0.81. Using SDA, results of the Cox analyses are transformed into a simple graph displaying a real-time individualized probability of disease complication and treatment response. CONCLUSIONS: We have developed a tool to predict and communicate individualized risks of CD complications and how this is modified by treatment. Once validated, it can be used at the bedside to facilitate patient decision making.

Common variants at five new loci associated with early-onset inflammatory bowel disease.

The inflammatory bowel diseases (IBD) Crohn's disease and ulcerative colitis are common causes of morbidity in children and young adults in the western world. Here we report the results of a genome-wide association study in early-onset IBD involving 3,426 affected individuals and 11,963 genetically matched controls recruited through international collaborations in Europe and North America, thereby extending the results from a previous study of 1,011 individuals with early-onset IBD. We have identified five new regions associated with early-onset IBD susceptibility, including 16p11 near the cytokine gene IL27 (rs8049439, P = 2.41 x 10(-9)), 22q12 (rs2412973, P = 1.55 x 10(-9)), 10q22 (rs1250550, P = 5.63 x 10(-9)), 2q37 (rs4676410, P = 3.64 x 10(-8)) and 19q13.11 (rs10500264, P = 4.26 x 10(-10)). Our scan also detected associations at 23 of 32 loci previously implicated in adult-onset Crohn's disease and at 8 of 17 loci implicated in adult-onset ulcerative colitis, highlighting the close pathogenetic relationship between early- and adult-onset IBD.

A new genetic subgroup of chronic granulomatous disease with autosomal recessive mutations in p40 phox and selective defects in neutrophil NADPH oxidase activity.

Chronic granulomatous disease (CGD), an immunodeficiency with recurrent pyogenic infections and granulomatous inflammation, results from loss of phagocyte superoxide production by recessive mutations in any 1 of 4 genes encoding subunits of the phagocyte NADPH oxidase. These include gp91(phox) and p22(phox), which form the membrane-integrated flavocytochrome b, and cytosolic subunits p47(phox) and p67(phox). A fifth subunit, p40(phox), plays an important role in phagocytosis-induced superoxide production via a phox homology (PX) domain that binds to phosphatidylinositol 3-phosphate (PtdIns(3)P). We report the first case of autosomal recessive mutations in NCF4, the gene encoding p40(phox), in a boy who presented with granulomatous colitis. His neutrophils showed a substantial defect in intracellular superoxide production during phagocytosis, whereas extracellular release of superoxide elicited by phorbol ester or formyl-methionyl-leucyl-phenylalanine (fMLF) was unaffected. Genetic analysis of NCF4 showed compound heterozygosity for a frameshift mutation with premature stop codon and a missense mutation predicting a R105Q substitution in the PX domain. Parents and a sibling were healthy heterozygous carriers. p40(phox)R105Q lacked binding to PtdIns(3)P and failed to reconstitute phagocytosis-induced oxidase activity in p40(phox)-deficient granulocytes, with premature loss of p40(phox)R105Q from phagosomes. Thus, p40(phox) binding to PtdIns(3)P is essential for phagocytosis-induced oxidant production in human neutrophils and its absence can be associated with disease.

Age of diagnosis influences serologic responses in children with Crohn's disease: a possible clue to etiology?

BACKGROUND: Crohn's disease (CD) is often associated with antibodies to microbial antigens. Differences in immune response may offer clues to the pathogenesis of the disease. The aim was to examine the influence of age at diagnosis on the serologic response in children with CD. METHODS: Data were drawn from 3 North American multicenter pediatric inflammatory bowel disease (IBD) research consortia. At or shortly after diagnosis, pANCA, ASCA IgA, ASCA IgG, anti-ompC, and anti-CBir1 were assayed. The results were compared as a function of age at CD diagnosis (0-7 years versus 8-15 years). RESULTS: In all, 705 children (79 <8 years of age at diagnosis, 626 >or=8 years) were studied. Small bowel CD was less frequent in the younger group (48.7% versus 72.6%; P < 0.0001), while colonic involvement was comparable (91.0% versus 86.5%). ASCA IgA and IgG were seen in <20% of those 0-7 years old compared to nearly 40% of those 8-15 years old (P < 0.001), while anti-CBir1 was more frequent in the younger children (66% versus 54%, P < 0.05). Anti-CBir1 detected a significant number of children in both age groups who otherwise were serologically negative. Both age at diagnosis and site of CD involvement were independently associated with expression of ASCA and anti-CBir1. CONCLUSIONS: Compared to children 8-15 years of age at diagnosis, those 0-7 years are more likely to express anti-CBir1 but only half as likely to express ASCA. These age-associated differences in antimicrobial seropositivity suggest that there may be different, and as yet unrecognized, genetic, immunologic, and/or microbial factors leading to CD in the youngest children.

Increased immune reactivity predicts aggressive complicating Crohn's disease in children.

BACKGROUND & AIMS: The ability to identify children with CD who are at highest risk for rapid progression from uncomplicated to complicated phenotypes would be invaluable in guiding initial therapy. The aims of this study were to determine whether immune responses and/or CARD15 variants are associated with complicated disease phenotypes and predict disease progression. METHODS: Sera were collected from 796 pediatric CD cases and tested for anti-Cbir1 (flagellin), anti-outer membrane protein C, anti-Saccharomyces cerevisiae, and perinuclear antineutrophil cytoplasmic antibody by using enzyme-linked immunosorbent assay. Genotyping (Taqman MGB) was performed for 3 CARD15 variants (single nucleotide polymorphisms 8, 12, and 13). Associations between immune responses (antibody sum and quartile sum score, CARD15, and clinical phenotype were evaluated. RESULTS: Thirty-two percent of patients developed at least 1 disease complication within a median of 32 months, and 18% underwent surgery. The frequency of internal penetrating, stricturing, and surgery significantly increased (P trend < .0001 for all 3 outcomes) with increasing antibody sum and quartile sum score. Nine percent of seropositive groups had internal penetrating/stricturing versus 2.9% in the seronegative group (P = .01). Twelve percent of seropositive groups underwent surgery versus 2% in the seronegative group (P = .0001). The highest antibody sum group (3) and quartile sum score group (4) demonstrated the most rapid disease progression (P < .0001). Increased hazard ratio was observed for antibody sum group 3 (7.8; confidence interval, 2.2-28.7), P < .002 and quartile sum score group 4 (11.0; confidence interval, 1.5-83.0, P < .02). CONCLUSIONS: The rate of complicated CD increases in children as the number and magnitude of immune reactivity increase. Disease progression is significantly faster in children expressing immune reactivity.

Biliary atresia: the Canadian experience.

OBJECTIVE: To determine the outcomes of Canadian children with biliary atresia. STUDY DESIGN: Health records of infants born in Canada between January 1, 1985 and December 31, 1995 (ERA I) and between January 1, 1996 and December 31, 2002 (ERA II) who were diagnosed with biliary atresia at a university center were reviewed. RESULTS: 349 patients were identified. Median patient age at time of the Kasai operation was 55 days. Median age at last follow-up was 70 months. The 4-year patient survival rate was 81% (ERA I = 74%; ERA II = 82%; P = not significant [NS]). Kaplan-Meier survival curves for patients undergoing the Kasai operation at age < or = 30, 31 to 90, and > 90 days showed 49%, 36%, and 23%, respectively, were alive with their native liver at 4 years (P < .0001). This difference continued through 10 years. The 2- and 4-year post-Kasai operation native liver survival rates were 47% and 35% for ERA I and 46% and 39% for ERA II (P = NS). A total of 210 patients (60%) underwent liver transplantation; the 4-year transplantation survival rate was 82% (ERA I = 83%, ERA II = 82%; P = NS). CONCLUSIONS: This is the largest outcome series of North American children with biliary atresia at a time when liver transplantation was available. Results in each era were similar. Late referral remains problematic; policies to ensure timely diagnosis are required. Nevertheless, outcomes in Canada are comparable to those reported elsewhere.

IL-23 receptor (IL-23R) gene protects against pediatric Crohn's disease.

BACKGROUND: The IL-23 receptor (IL-23R) has been found to be associated with small bowel Crohn's disease (CD) in a whole genome association study. Specifically, the rare allele of the R381Q single nucleotide polymorphism (SNP) conferred protection against CD. It is unknown whether IL-23R is associated with IBD in children. The aim was to examine the association of IL-23R with susceptibility to IBD in pediatric patients. METHODS: DNA was collected from 609 subjects (151 CD and 52 ulcerative colitis [UC] trios). Trios were genotyped for the R381Q SNP of the IL-23R gene and SNP8, SNP12, SNP13, of the CARD15 gene using Taqman. The transmission disequilibrium test (TDT) was used for association to disease using GENEHUNTER 2.0. RESULTS: The rare allele of R381Q SNP was present in 2.7% of CD and 2.9% UC probands. The CARD15 frequency was 31.5% (CD) and 18% (UC). The IL-23R allele was negatively associated with inflammatory bowel disease (IBD): the R381Q SNP was undertransmitted in children with IBD (8 transmitted [T] versus 27 untransmitted [UT]; P = 0.001). This association was significant for all CD patients (6 T versus 19 UT; P = 0.009), especially for non-Jewish CD patients (2 T versus 17 UT; P = 0.0006). TDT showed a borderline association for UC (2 T versus 8 UT; P = 0.06). As expected, CARD15 was associated with CD in children by the TDT (58 T versus 22 UT P = 0.00006), but not with UC. CONCLUSIONS: The protective IL-23R R381Q variant was particularly associated with CD in non-Jewish children. Thus, the initial whole genome association study based on ileal CD in adults has been extended to the pediatric population and beyond small bowel CD.

Serum immune responses predict rapid disease progression among children with Crohn's disease: immune responses predict disease progression.

BACKGROUND AND AIM: Crohn's disease (CD) is a heterogeneous disorder characterized by diverse clinical phenotypes. Childhood-onset CD has been described as a more aggressive phenotype. Genetic and immune factors may influence disease phenotype and clinical course. We examined the association of immune responses to microbial antigens with disease behavior and prospectively determined the influence of immune reactivity on disease progression in pediatric CD patients. METHODS: Sera were collected from 196 pediatric CD cases and tested for immune responses: anti-I2, anti-outer membrane protein C (anti-OmpC), anti-CBir1 flagellin (anti-CBir1), and anti-Saccharomyces-cerevisiae (ASCA) using ELISA. Associations between immune responses and clinical phenotype were evaluated. RESULTS: Fifty-eight patients (28%) developed internal penetrating and/or stricturing (IP/S) disease after a median follow-up of 18 months. Both anti-OmpC (p < 0.0006) and anti-I2 (p < 0.003) were associated with IP/S disease. The frequency of IP/S disease increased with increasing number of immune responses (p trend = 0.002). The odds of developing IP/S disease were highest in patients positive for all four immune responses (OR (95% CI): 11 (1.5-80.4); p = 0.03). Pediatric CD patients positive for > or =1 immune response progressed to IP/S disease sooner after diagnosis as compared to those negative for all immune responses (p < 0.03). CONCLUSIONS: The presence and magnitude of immune responses to microbial antigens are significantly associated with more aggressive disease phenotypes among children with CD. This is the first study to prospectively demonstrate that the time to develop a disease complication in children is significantly faster in the presence of immune reactivity, thereby predicting disease progression to more aggressive disease phenotypes among pediatric CD patients.