Simple Endoscopic Score of Crohn Disease and Magnetic Resonance Enterography in Children: Report From ImageKids Study.

OBJECTIVES: We aimed to explore the ability of magnetic resonance enterography (MRE) to impute the simple endoscopic score of Crohn disease (SES-CD) in children with CD, in whom failure of ileal intubation is common and may impair SES-CD calculation in clinical studies. METHODS: This is a substudy of the prospective ImageKids study in which children with CD underwent ileocolonoscopy (scored by SES-CD) and MRE (scored on a 100 mm visual analogue scale [VAS] and by MaRIA). Mucosal healing (MH) was defined as SES-CD <3, MRE-VAS <20 mm, and/or MaRIA <7. RESULTS: A total of 237 children (22 centers, age 11.5 ±â€Š3.3 years), were enrolled. Ileal intubation has failed in 40 of 237 (17%). The agreement between SES-CD and MRE was 75% (k = 0.508, P < 0.001) in the ileum, and 68% to 85% in the colonic segments (k = 0.21-0.50, P < 0.001). The sensitivity and specificity of ileal MRE-VAS for MH were 91.7% (95% confidence interval 0.84-0.96) and 53.1% (95% confidence interval 0.43-0.63), respectively. The ileal MaRIA score (calculated in 33/40) was higher in the children without ileal intubation than in the others (20.5 ±â€Š7.1 vs 15.1 ±â€Š10.8, respectively, P = 0.0018). In 7% (16/237) of children, isolated active ileal disease would have been missed when considering SES-CD only. A multivariable model predicted the ileal SES-CD subscore from the MaRIA: SES-CDileum = 1.145 + 0.169 × MaRIAileum rounded to the nearest whole number (R = 0.17). Applying this model to the children without ileal intubation revealed that 29 of 33 (88%) had ileal disease; 8 of 29 patients (28%) with normal colonic SES-CD had imputed ileal SES-CD ≥3. CONCLUSIONS: MRE is useful for imputing the ileal disease in pediatric clinical studies, overcoming the problem of ileal nonintubation.

Durability of Infliximab Is Associated With Disease Extent in Children With Inflammatory Bowel Disease.

OBJECTIVES: The aim of the study was to evaluate infliximab (IFX) dosing and treatment durability relative to luminal disease burden in patients with inflammatory bowel disease. METHODS: Records from 98 pediatric patients treated with IFX between 2012 and 2014 were reviewed. Disease extent was classified as "limited," "moderate," or "extensive" based on cumulative assessment of mucosal involvement. Patients started taking standard 5 mg/kg dosing were compared with those initiated taking 10 mg/kg with regard to treatment durability. RESULTS: Overall, 26.4%, 58.3%, and 70% with limited, moderate, or extensive disease, respectively, started taking a standard IFX dose of 5 mg/kg required therapy escalation. Patients with moderate and extensive disease, started taking the 5 mg/kg per dose, showed statistically significant shorter times to escalation than those with limited disease. The percentage of patients remaining on their initial 5 mg/kg per dose at 12 months was 80.1%, 56.9%, and 40.0% for limited, moderate, and extensive disease, respectively. Among patients started taking 10 mg/kg, 100% remained on this dose. All the patients with limited disease who required dose escalation continued on the higher dose at the time of analysis; however, among those with the most extensive disease, 43% failed escalation because of nonresponse or infusion reaction. CONCLUSIONS: Patients with extensive disease started taking 5 mg/kg of IFX were more likely to require dose escalation compared to those with limited or moderate disease. All of the patients with moderate and extensive disease started taking 10 mg/kg of IFX remained on this dose. These results suggest that patients with more extensive disease may benefit from higher initial IFX dosing as it relates to durability of the treatment.

Associative interference and nonreinforcement in human contingency learning.

This article reports three experiments comparing the impact on contingency assessment of associative cue interference (proactive, interspersed, and retroactive) and nonreinforcement (latent inhibition, partial reinforcement, and extinction). All three experiments used variants of the rapid trial streaming procedure developed by Allan and collaborators. Participants were exposed to stimulus streams and then asked how likely it was for a target cue to be accompanied (Experiment 1) or to be followed (Experiments 2 and 3) by a target outcome. Experiments 1 and 2 looked at interference and found that when the objective target cue-outcome contingency is positive, interspersed interference is more effective than either proactive or retroactive interference. Experiment 2 additionally showed that this conclusion was a function of the target cue-outcome contingency: when the number of cue-outcome pairings was low, retroactive interference was more efficient than interspersed interference. Experiment 3 examined nonreinforcement and found that the efficacies of latent inhibition, partial reinforcement, and extinction are also a function of the target cue-outcome contingency, but the pattern differed greatly from what was observed in Experiment 2. When the number of cue-outcome pairings was high, there was no difference between latent inhibition, partial reinforcement, and extinction. When the number of cue-outcome pairings was low, extinction did not lower the contingency judgement, whereas latent inhibition and partial reinforcement did.

Feasibility of using MR enterography for the assessment of terminal ileitis and inflammatory activity in children with Crohn disease.

BACKGROUND AND OBJECTIVE: Radiation exposure increases cancer risk in children with Crohn disease (CD). Magnetic resonance enterography (MRE) can image the gastrointestinal tract without exposure to radiation. The aim of the present study was to determine whether our MRE protocol could diagnose terminal ileitis and the degree of inflammatory activity in children with CD. METHODS: Retrospective review of patients 18 years of age or younger who underwent MRE for known or suspected CD from June 15, 2007 to April 1, 2010. MRE was performed with Volumen and water as oral contrast and gadolinium-based intravenous contrast. No antiperistaltic agent was used. Each MRE was compared with ileal biopsies obtained within 90 days. Severity of inflammation on MRE was scored and compared with the Pediatric Crohn Disease Activity Index (PCDAI). RESULTS: Seventy-two patients underwent 80 MREs during the study period. Forty-two of the 72 patients (58.3%) underwent colonoscopy within 90 days of MRE, and the terminal ileum was intubated in 33. Compared with histology, MRE had a sensitivity of 71.4% and a specificity of 100% for terminal ileitis. The positive and negative predictive values were 100% and 70%, respectively. PCDAI was calculated in 39 of the 72 patients (54.2%) and had a statistically significant positive correlation with MRE score of 0.37 (P = 0.020426). CONCLUSIONS: In children with known or suspected CD, our MRE protocol has a high specificity and positive predictive value for terminal ileitis. Severity of inflammation on MRE had a statistically significant positive correlation with PCDAI.