Identification and multimodal characterization of a specialized epithelial cell type associated with Crohn's disease.

Crohn's disease (CD) is a complex chronic inflammatory disorder with both gastrointestinal and extra-intestinal manifestations associated immune dysregulation. Analyzing 202,359 cells from 170 specimens across 83 patients, we identify a distinct epithelial cell type in both terminal ileum and ascending colon (hereon as 'LND') with high expression of LCN2, NOS2, and DUOX2 and genes related to antimicrobial response and immunoregulation. LND cells, confirmed by in-situ RNA and protein imaging, are rare in non-IBD controls but expand in active CD, and actively interact with immune cells and specifically express IBD/CD susceptibility genes, suggesting a possible function in CD immunopathogenesis. Furthermore, we discover early and late LND subpopulations with different origins and developmental potential. A higher ratio of late-to-early LND cells correlates with better response to anti-TNF treatment. Our findings thus suggest a potential pathogenic role for LND cells in both Crohn's ileitis and colitis.

The Comorbidity of Patient-Reported Crohn's Disease Activity and Depression: The Role of Health Behavior Mediators.

Background: Longitudinal research reveals a unidirectional relationship between a nonsomatic symptom of depression, a negative view of the self, and later reported Crohn's disease (CD) activity. We evaluated whether health behaviors mediated this association using a longitudinal design. Methods: We studied 3304 adult volunteers with a self-reported diagnosis of CD who completed a baseline survey that included demographics, CD activity, a symptom-specific index of depression, and measures of physical activity, smoking, and sleep quality. Crohn's disease status and the cognitive index of depression were also measured 6 and 12 months after the baseline evaluation. We specified single-mediator and multiple-mediator models to elucidate the depression-disease activity relationship. Results: Among 2395 females and 909 males, we found a significant mediation effect for activity level (P < .001) after adjusting for age, sex, and body mass index. There was no evidence that sleep quality and smoking are significant single mediators. When we considered multiple mediation models, smoking and less activity partially mediate the depression-CD association. Conclusions: Smoking and lower levels of physical activity are potential mediators of the unidirectional association between a nonsomatic symptom of depression-a negative view of the self-and patient-reported CD activity. Evaluating and treating specific symptoms of depression may reduce the frequency of CD exacerbations.

A Specialized Epithelial Cell Type Regulating Mucosal Immunity and Driving Human Crohn's Disease.

Crohn's disease (CD) is a complex chronic inflammatory disorder that may affect any part of gastrointestinal tract with extra-intestinal manifestations and associated immune dysregulation. To characterize heterogeneity in CD, we profiled single-cell transcriptomics of 170 samples from 65 CD patients and 18 non-inflammatory bowel disease (IBD) controls in both the terminal ileum (TI) and ascending colon (AC). Analysis of 202,359 cells identified a novel epithelial cell type in both TI and AC, featuring high expression of LCN2, NOS2, and DUOX2, and thus is named LND. LND cells, confirmed by high-resolution in-situ RNA imaging, were rarely found in non-IBD controls, but expanded significantly in active CD. Compared to other epithelial cells, genes defining LND cells were enriched in antimicrobial response and immunoregulation. Moreover, multiplexed protein imaging demonstrated that LND cell abundance was associated with immune infiltration. Cross-talk between LND and immune cells was explored by ligand-receptor interactions and further evidenced by their spatial colocalization. LND cells showed significant enrichment of expression specificity of IBD/CD susceptibility genes, revealing its role in immunopathogenesis of CD. Investigating lineage relationships of epithelial cells detected two LND cell subpopulations with different origins and developmental potential, early and late LND. The ratio of the late to early LND cells was related to anti-TNF response. These findings emphasize the pathogenic role of the specialized LND cell type in both Crohn's ileitis and Crohn's colitis and identify novel biomarkers associated with disease activity and treatment response.

Safety and Efficacy of Vedolizumab Versus Tumor Necrosis Factor α Antagonists in an Elderly IBD Population: A Single Institution Retrospective Experience.

BACKGROUND: Vedolizumab is a monoclonal antibody used to treat inflammatory bowel disease (IBD). There is little known about the safety and comparative efficacy of this agent in the elderly population. AIMS: Here, we present data on the safety and comparative efficacy of vedolizumab versus tumor necrosis factor α antagonists (anti-TNF) in elderly patients with IBD. METHODS: This retrospective cohort study included IBD patients started on vedolizumab or anti-TNF at age 60 or older at a single tertiary IBD center. Safety was evaluated by assessing for the development of serious infection. The comparative needs for IBD-related surgery, IBD-related hospitalization, and drug discontinuation for any reason were obtained. Efficacy was assessed by comparing changes in endoscopic, histologic, and patient-report outcomes. RESULTS: 212 cases were identified-108 patients treated with vedolizumab and 104 patients treated with anti-TNF. There were no significant differences between cohorts in serious infection, surgical intervention, or IBD-hospitalization-free survival (p = NS). Drug discontinuation survival was different between anti-TNF and vedolizumab (p = 0.02) with more patients remaining on vedolizumab at the time of last follow-up (51.9% vs. 25.9%). Endoscopic remission and response rates were higher in the vedolizumab versus anti-TNF group (65.7% vs. 45.2%, p = 0.02; 80.0% vs. 59.3%, p < 0.001). CONCLUSIONS: In a cohort of IBD patients over age 60, vedolizumab showed no statistically significant differences in infection, hospitalization, or surgical intervention-free survival as compared to anti-TNF. Vedolizumab was discontinued less frequently than anti-TNF. Patients on vedolizumab had higher rates of endoscopic remission and response.

Tofacitinib Adherence and Outcomes in Refractory Inflammatory Bowel Disease.

Background: Tofacitinib has been approved for moderate-to-severe ulcerative colitis and studied in Crohn's disease. Understanding medication adherence to oral medications in severe disease is essential. Methods: We retrospectively reviewed adherence and real-world outcomes of inflammatory bowel disease patients who initiated tofacitinib at a single care center. Adherence was measured by proportion of days covered. Results: Sixty-three patients were identified. All patients failed at least one prior biologic therapy. Mean proportion of days covered was 95.7% for ulcerative colitis and 93.1% for Crohn's disease. Significant clinical and endoscopic response was seen. Conclusion: Adherence was high in a cohort with highly refractory disease.

Increased Incidence and Mortality of Gastric Cancer in Immigrant Populations from High to Low Regions of Incidence: A Systematic Review and Meta-Analysis.

BACKGROUND & AIMS: Gastric cancer is the leading cause of infection-related cancer death and the third-leading cause of cancer death worldwide. The effect of immigration on gastric cancer risk is not well-defined but might be helpful for screening or surveillance endeavors. We performed a systematic review and meta-analysis to define the risk of gastric cancer in immigrants from high-incidence regions to low-incidence regions (including Western Europe, Australia, Brazil, Canada, Israel, and the United States). METHODS: We searched MEDLINE and EMBASE databases, from January 1980 to January 2019, for studies that identified immigrants from high-incidence regions of gastric cancer, provided clear definitions of immigrant and reference populations, and provided sufficient data to calculate gastric cancer incidence and gastric cancer-related mortality. We performed meta-analyses of standardized incidence ratios (SIR) for first-generation immigrants from high- to low-incidence regions, stratified by immigrant generation, sex, and anatomic and histologic subtype, when data were available. RESULTS: We identified 38 cohort studies that met our inclusion criteria. All 13 studies of 21 distinct populations reported significantly increased SIRs for gastric cancer in first-generation foreign-born immigrants (men SIR range, 1.24-4.50 and women SIR range, 1.27-5.05). The pooled SIR for immigrants with all types of gastric cancer was 1.66 (95% CI, 1.52-1.80) for men and 1.83 (95% CI, 1.69-1.98) for women. Nine studies from 2 high-incidence populations (the former Soviet Union and Japan) reported an increased gastric cancer standardized mortality ratio in first-generation immigrants who migrated to regions of low incidence (former Soviet Union immigrants, 1.44-1.91 for men and 1.40-2.56 for women). CONCLUSIONS: Immigrants from regions with a high incidence of gastric cancer to regions of low incidence maintain a higher risk of gastric cancer and related mortality, based on a comprehensive systematic review and meta-analysis. Assessment of immigrant generation along with other risk factors might help identify high-risk populations for prevention and therapeutic interventions.