Low Anti-Tumor Necrosis Factor Levels During Maintenance Phase Are Associated With Treatment Failure in Children With Crohn's Disease.

BACKGROUND: Higher drug levels and combination therapy with low-dose oral methotrexate (LD-MTX) may reduce anti-tumor necrosis factor (TNF) treatment failure in pediatric Crohn's disease. We sought to (1) evaluate whether combination therapy with LD-MTX was associated with higher anti-TNF levels, (2) evaluate associations between anti-TNF levels and subsequent treatment failure, and (3) explore the effect of combination therapy on maintenance of remission among patients with therapeutic drug levels (>5 µg/mL for infliximab and >7.5 µg/mL for adalimumab). METHODS: We conducted a post hoc analysis of the COMBINE trial, which compared anti-TNF monotherapy to combination therapy with LD-MTX. We included participants who entered maintenance therapy and provided a serum sample approximately 4 months from randomization. RESULTS: Among 112 infliximab and 41 adalimumab initiators, median drug levels were similar between combination therapy and monotherapy (infliximab: 8.8 vs 7.5 µg/mL [P = .49]; adalimumab: 11.1 vs 10.5 µg/mL [P = .11]). Median drug levels were lower in patients experiencing treatment failure (infliximab: 4.2 vs 9.6 µg/mL [P < .01]; adalimumab: 9.1 vs 12.3 µg/mL [P < .01]). Among patients treated with infliximab with therapeutic drug levels, we observed no difference in treatment failure between participants assigned monotherapy or combination therapy. Among patients treated with adalimumab, a trend towards reduced treatment failure in the combination therapy arm was not statistically significant (P = .14). CONCLUSIONS: LD-MTX combination was not associated with higher drug levels, but higher drug levels were associated with reduced risk of treatment failure. Among patients with therapeutic drug levels, we observed no benefit of LD-MTX for patients treated with infliximab. A nonsignificant trend towards reduced treatment failure with the addition of LD-MTX patients treated with adalimumab warrants further investigation.

For children with Crohn's disease treated with biologic medications, with and without low-dose methotrexate, the role of drug levels on treatment failure in a recent prospective trial is unclear. These data suggest patients on infliximab with therapeutic drug levels are more likely to continue any therapy, and the effect on patients treated with adalimumab requires more investigation.

Travel Time to Treating Center is Associated With Diagnostic Delay in Pediatric Inflammatory Bowel Disease.

BACKGROUND & AIMS: Delayed diagnosis of inflammatory bowel disease (IBD) leads to prolonged symptoms and worse long-term outcomes. We sought to evaluate whether race, ethnicity, disease type, and social factors are associated with delayed diagnosis of pediatric IBD. METHODS: We performed a cross-sectional study of newly diagnosed pediatric patients with IBD at 22 United States sites from 2019 to 2022. Parents/guardians reported race, ethnicity, time between symptom onset and diagnosis, and other social determinants of health. Through bivariate and multivariable analyses using generalized estimating equations, we evaluated associations between these factors and diagnosis time defined as ≤60 days, 61 to 180 days, 181 to 365 days, and >365 days. RESULTS: We enrolled 869 participants (mean age at diagnosis, 13.1 years; 52% male; 57% Crohn's disease [CD]; 34% ulcerative colitis [UC]; 8% Hispanic; 30% non-White). Overall, the mean time to diagnosis was 265.9 days. After adjustment, factors associated with longer diagnosis time included CD vs UC (odds ratio [OR], 2.6; 95% confidence interval [CI], 1.9-3.5), 2 or more other health conditions (OR, 1.7; 95% CI, 1.1-2.7), and longer travel time to clinic (>1 hour [OR, 1.7; 95% CI, 1.2-2.4], >2 hours (OR, 1.8; 95% CI, 1.2-2.9] each vs <30 minutes). There was no association with race, ethnicity, birth country, gender, parent education, household income, insurance type, health literacy, and health system distrust. CONCLUSIONS: Consistent with prior literature, diagnostic delay is longer for CD than UC. Reassuringly, time to diagnosis is equitable across racioethnic groups. New models of diagnostic care are needed for communities affected by longer travel times.

Ileal Derived Organoids From Crohn's Disease Patients Show Unique Transcriptomic and Secretomic Signatures.

BACKGROUND & AIMS: We used patient-derived organoids (PDOs) to study the epithelial-specific transcriptional and secretome signatures of the ileum during Crohn's disease (CD) with varying phenotypes to screen for disease profiles and potential druggable targets. METHODS: RNA sequencing was performed on isolated intestinal crypts and 3-week-old PDOs derived from ileal biopsies of CD patients (n = 8 B1, inflammatory; n = 8 B2, stricturing disease) and non-inflammatory bowel disease (IBD) controls (n = 13). Differentially expressed (DE) genes were identified by comparing CD vs control, B1 vs B2, and inflamed vs non-inflamed. DE genes were used for computational screening to find candidate small molecules that could potentially reverse B1and B2 gene signatures. The secretome of a second cohort (n = 6 non-IBD controls, n = 7 CD, 5 non-inflamed, 2 inflamed) was tested by Luminex using cultured organoid conditioned medium. RESULTS: We found 90% similarity in both the identity and abundance of protein coding genes between PDOs and intestinal crypts (15,554 transcripts of 19,900 genes). DE analysis identified 814 genes among disease group (CD vs non-IBD control), 470 genes different between the CD phenotypes, and 5 false discovery rate correction significant genes between inflamed and non-inflamed CD. The PDOs showed both similarity and diversity in the levels and types of soluble cytokines and growth factors they released. Perturbagen analysis revealed potential candidate compounds to reverse B2 disease phenotype to B1 in PDOs. CONCLUSIONS: PDOs are similar at the transcriptome level with the in vivo epithelium and retain disease-specific gene expression for which we have identified secretome products, druggable targets, and corresponding pharmacologic agents. Targeting the epithelium could reverse a stricturing phenotype and improve outcomes.

Similar Long-Term Outcomes in Children Presenting With Abscess vs Phlegmon at Diagnosis of Crohn Disease.

Background: Limited data are available for long-term outcomes of pediatric patients with abdominal abscess or phlegmon at diagnosis of Crohn disease. Methods: We performed a retrospective chart review of such children over a recent 6-year period at 5 pediatric inflammatory bowel diseases. Results: Fifty-two patients (mean age 15.9 ± 1.8 years) were reviewed. Thirty-six had an abscess and 27 (75%) required resectional therapy compared to 16 with phlegmon which 10 (63%) requiring surgery. Overall (37/52) 71% had surgery which was performed within 6 months in 32 (86%). Conclusions: A similar high surgical rate exists whether pediatric patients with Crohn disease present with abscess or phlegmon.