Antonio Quiros

Serum Immune Responses Predict Rapid Disease Progression among Children with Crohn's Disease: Immune Responses Predict Disease Progression

BACKGROUND AND AIM:Crohns 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 ≥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.

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.

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 Crohns 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. (Inflamm Bowel Dis 2007)

A review of activity indices and end points for clinical trials in children with Crohn's disease

&NA; The necessity to include children and adolescents in clinical trials is increasingly recognized. Two recent workshops provided the impetus for pediatric gastroenterologists to develop evidence‐based recommendations concerning end points and outcome assessment in cases of pediatric Crohns disease. The overall goal was to facilitate clinical trial design by standardizing the methodology. This article critically reviews the available assessment tools and provides consensus recommendations for the evaluation of linear growth, disease activity, and health‐related quality of life in clinical trials in pediatric Crohns disease.

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.