Pre-operative visceral adipose tissue radiodensity is a potentially novel prognostic biomarker for early endoscopic post-operative recurrence in Crohn's disease.

BACKGROUND: Evidence suggests inflammatory mesenteric fat is involved in post-operative recurrence (POR) of Crohn's disease (CD). However, its prognostic value is uncertain, in part, due to difficulties studying it non-invasively. AIM: To evaluate the prognostic value of pre-operative radiographic mesenteric parameters for early endoscopic POR (ePOR). METHODS: We conducted a retrospective cohort study of CD subjects ≥ 12 years who underwent ileocecal or small bowel resection between 1/1/2007 to 12/31/2021 with computerized tomography abdomen/pelvis ≤ 6 months pre-operatively and underwent ileocolonoscopy ≤ 15 months post-operatively. Visceral adipose tissue (VAT) volume (cm3), ratio of VAT:subcutaneous adipose tissue (SAT) volume, VAT radiodensity, and ratio of VAT:SAT radiodensity were generated semiautomatically. Mesenteric lymphadenopathy (LAD, largest lymph node > 10 mm) and severe vasa recta (VR) engorgement (diameter of the VR supplying diseased bowel ≥ 2 × VR supplying healthy bowel) were derived manually. The primary outcome was early ePOR (Rutgeert's score ≥ i2 on first endoscopy ≤ 15 months post-operatively) and the secondary outcome was ePOR severity (Rutgeert's score i0-4). Regression analyses were performed adjusting for demographic and disease-related characteristics to calculate adjusted odds ratio (aOR) and 95% confidence interval (CI). RESULTS: Of the 139 subjects included, 45% of subjects developed early ePOR (n = 63). VAT radiodensity (aOR 0.59, 95%CI: 0.38-0.90) and VAT:SAT radiodensity (aOR 8.54, 95%CI: 1.48-49.28) were associated with early ePOR, whereas, VAT volume (aOR 1.23, 95%CI: 0.78-1.95), VAT:SAT volume (aOR 0.80, 95%CI: 0.53-1.20), severe VR engorgement (aOR 1.53, 95%CI: 0.64-3.66), and mesenteric LAD (aOR 1.59, 95%CI: 0.67-3.79) were not. Similar results were observed for severity of ePOR. CONCLUSION: VAT radiodensity is potentially a novel non-invasive prognostic imaging marker to help risk stratify CD patients for POR.

T cell protein tyrosine phosphatase protects intestinal barrier function by restricting epithelial tight junction remodeling.

Genome-wide association studies revealed that loss-of-function mutations in protein tyrosine phosphatase non-receptor type 2 (PTPN2) increase the risk of developing chronic immune diseases, such as inflammatory bowel disease (IBD) and celiac disease. These conditions are associated with increased intestinal permeability as an early etiological event. The aim of this study was to examine the consequences of deficient activity of the PTPN2 gene product, T cell protein tyrosine phosphatase (TCPTP), on intestinal barrier function and tight junction organization in vivo and in vitro. Here, we demonstrate that TCPTP protected against intestinal barrier dysfunction induced by the inflammatory cytokine IFN-γ by 2 mechanisms: it maintained localization of zonula occludens 1 and occludin at apical tight junctions and restricted both expression and insertion of the cation pore-forming transmembrane protein, claudin-2, at tight junctions through upregulation of the inhibitory cysteine protease, matriptase. We also confirmed that the loss-of-function PTPN2 rs1893217 SNP was associated with increased intestinal claudin-2 expression in patients with IBD. Moreover, elevated claudin-2 levels and paracellular electrolyte flux in TCPTP-deficient intestinal epithelial cells were normalized by recombinant matriptase. Our findings uncover distinct and critical roles for epithelial TCPTP in preserving intestinal barrier integrity, thereby proposing a mechanism by which PTPN2 mutations contribute to IBD.

Anti-SARS-CoV-2 antibody responses are attenuated in patients with IBD treated with infliximab.

OBJECTIVE: Antitumour necrosis factor (anti-TNF) drugs impair protective immunity following pneumococcal, influenza and viral hepatitis vaccination and increase the risk of serious respiratory infections. We sought to determine whether infliximab-treated patients with IBD have attenuated serological responses to SARS-CoV-2 infections. DESIGN: Antibody responses in participants treated with infliximab were compared with a reference cohort treated with vedolizumab, a gut-selective anti-integrin α4ß7 monoclonal antibody that is not associated with impaired vaccine responses or increased susceptibility to systemic infections. 6935 patients were recruited from 92 UK hospitals between 22 September and 23 December 2020. RESULTS: Rates of symptomatic and proven SARS-CoV-2 infection were similar between groups. Seroprevalence was lower in infliximab-treated than vedolizumab-treated patients (3.4% (161/4685) vs 6.0% (134/2250), p<0.0001). Multivariable logistic regression analyses confirmed that infliximab (vs vedolizumab; OR 0.66 (95% CI 0.51 to 0.87), p=0.0027) and immunomodulator use (OR 0.70 (95% CI 0.53 to 0.92), p=0.012) were independently associated with lower seropositivity. In patients with confirmed SARS-CoV-2 infection, seroconversion was observed in fewer infliximab-treated than vedolizumab-treated patients (48% (39/81) vs 83% (30/36), p=0.00044) and the magnitude of anti-SARS-CoV-2 reactivity was lower (median 0.8 cut-off index (0.2-5.6) vs 37.0 (15.2-76.1), p<0.0001). CONCLUSIONS: Infliximab is associated with attenuated serological responses to SARS-CoV-2 that were further blunted by immunomodulators used as concomitant therapy. Impaired serological responses to SARS-CoV-2 infection might have important implications for global public health policy and individual anti-TNF-treated patients. Serological testing and virus surveillance should be considered to detect suboptimal vaccine responses, persistent infection and viral evolution to inform public health policy. TRIAL REGISTRATION NUMBER: ISRCTN45176516.

Interaction between smoking and ATG16L1T300A triggers Paneth cell defects in Crohn's disease.

It is suggested that subtyping of complex inflammatory diseases can be based on genetic susceptibility and relevant environmental exposure (G+E). We propose that using matched cellular phenotypes in human subjects and corresponding preclinical models with the same G+E combinations is useful to this end. As an example, defective Paneth cells can subtype Crohn's disease (CD) subjects; Paneth cell defects have been linked to multiple CD susceptibility genes and are associated with poor outcome. We hypothesized that CD susceptibility genes interact with cigarette smoking, a major CD environmental risk factor, to trigger Paneth cell defects. We found that both CD subjects and mice with ATG16L1T300A (T300A; a prevalent CD susceptibility allele) developed Paneth cell defects triggered by tobacco smoke. Transcriptional analysis of full-thickness ileum and Paneth cell-enriched crypt base cells showed the T300A-smoking combination altered distinct pathways, including proapoptosis, metabolic dysregulation, and selective downregulation of the PPARγ pathway. Pharmacologic intervention by either apoptosis inhibitor or PPARγ agonist rosiglitazone prevented smoking-induced crypt apoptosis and Paneth cell defects in T300A mice and mice with conditional Paneth cell-specific knockout of Atg16l1. This study demonstrates how explicit G+E can drive disease-relevant phenotype and provides rational strategies for identifying actionable targets.

Serological, genetic and clinical associations with increased health-care resource utilization in inflammatory bowel disease.

OBJECTIVE: Inflammatory bowel diseases (IBD) are associated with significant morbidity and economic burden. The variable course of IBD creates a need for predictors of clinical outcomes and health resource utilization (HRU) to guide treatment decisions. We aimed to identify clinical, serological or genetic markers associated with inpatient resource utilization in patients with ulcerative colitis (UC) and Crohn's disease (CD). METHODS: Patients with IBD with available genetic and serological data who had at least one emergency department visit or hospitalization in a 3-year period were included. The primary outcome measure was HRU, as measured by the All Patient Refined Diagnosis Related Group classification system. Univariate and multivariate linear and logistic regression models were used to identify the associations with HRU. RESULTS: Altogether 858 (562 CD and 296 UC) patients were included. Anti-CBir1 seropositivity (P = 0.002, effect size [ES]: 0.762, 95% confidence interval [CI] 0.512-1.012) and low socioeconomic status (P = 0.005, ES: 1.620 [95% CI 1.091-2.149]) were independently associated with a high HRU. CD diagnosis (P = 0.006, ES: -0.701 [95% CI -0.959 to -0.443]) was independently associated with a low inpatient HRU. CONCLUSION: In patients with IBD who required at least one emergency department visit or hospitalization, anti-CBir1 antibody status may be a useful biomarker of HRU when formulating management strategies to reduce disease complications and resource utilization.

Genetic associations with adverse events from anti-tumor necrosis factor therapy in inflammatory bowel disease patients.

AIM: To study the type and frequency of adverse events associated with anti-tumor necrosis factor (TNF) therapy and evaluate for any serologic and genetic associations. METHODS: This study was a retrospective review of patients attending the inflammatory bowel disease (IBD) centers at Cedars-Sinai IBD Center from 2005-2016. Adverse events were identified via chart review. IBD serologies were measured by ELISA. DNA samples were genotyped at Cedars-Sinai using Illumina Infinium Immunochipv1 array per manufacturer's protocol. SNPs underwent methodological review and were evaluated using several SNP statistic parameters to ensure optimal allele-calling. Standard and rigorous QC criteria were applied to the genetic data, which was generated using immunochip. Genetic association was assessed by logistic regression after correcting for population structure. RESULTS: Altogether we identified 1258 IBD subjects exposed to anti-TNF agents in whom Immunochip data were available. 269/1258 patients (21%) were found to have adverse events to an anti-TNF-α agent that required the therapy to be discontinued. 25% of women compared to 17% of men experienced an adverse event. All adverse events resolved after discontinuing the anti-TNF agent. In total: n = 66 (5%) infusion reactions; n = 49 (4%) allergic/serum sickness reactions; n = 19 (1.5%) lupus-like reactions, n = 52 (4%) rash, n = 18 (1.4%) infections. In Crohn's disease, IgA ASCA (P = 0.04) and IgG-ASCA (P = 0.02) levels were also lower in patients with any adverse events, and anti-I2 level in ulcerative colitis was significantly associated with infusion reactions (P = 0.008). The logistic regression/human annotation and network analyses performed on the Immunochip data implicated the following five signaling pathways: JAK-STAT (Janus Kinase-signal transducer and activator of transcription), measles, IBD, cytokine-cytokine receptor interaction, and toxoplasmosis for any adverse event. CONCLUSION: Our study shows 1 in 5 IBD patients experience an adverse event to anti-TNF therapy with novel serologic, genetic , and pathways associations.

LRRK2 but not ATG16L1 is associated with Paneth cell defect in Japanese Crohn's disease patients.

BACKGROUND. Morphological patterns of Paneth cells are a prognostic biomarker in Western Crohn's disease (CD) patients, and are associated with autophagy-associated ATG16L1 and NOD2 variants. We hypothesized that genetic determinants of Paneth cell phenotype in other ethnic CD cohorts are distinct but also involved in autophagy. METHODS. We performed a hypothesis-driven analysis of 56 single nucleotide polymorphisms (SNPs) associated with CD susceptibility or known to affect Paneth cell function in 110 Japanese CD patients who underwent ileal resection. We subsequently performed a genome-wide association analysis. Paneth cell phenotype was determined by defensin-5 immunofluorescence. Selected genotype-Paneth cell defect correlations were compared to a Western CD cohort (n = 164). RESULTS. The average percentage of abnormal Paneth cells in Japanese CD was similar to Western CD (P = 0.87), and abnormal Paneth cell phenotype was also associated with early recurrence (P = 0.013). In contrast to Western CD, ATG16L1 T300A was not associated with Paneth cell defect in Japanese CD (P = 0.20). Among the 56 selected SNPs, only LRRK2 M2397T showed significant association with Paneth cell defect (P = 3.62 × 10-4), whereas in the Western CD cohort it was not (P = 0.76). Pathway analysis of LRRK2 and other candidate genes with P less than 5 × 10-4 showed connections with known CD susceptibility genes and links to autophagy and TNF-α networks. CONCLUSIONS. We found dichotomous effects of ATG16L1 and LRRK2 on Paneth cell defect between Japanese and Western CD. Genes affecting Paneth cell phenotype in Japanese CD were also associated with autophagy. Paneth cell phenotype also predicted prognosis in Japanese CD. FUNDING. Helmsley Charitable Trust, Doris Duke Foundation (grant 2014103), Japan Society for the Promotion of Science (KAKENHI grants JP15H04805 and JP15K15284), Crohn's and Colitis Foundation grant 274415, NIH (grants 1R56DK095820, K01DK109081, and UL1 TR000448).

Paneth cell defects in Crohn's disease patients promote dysbiosis.

BACKGROUND: Paneth cell dysfunction has been implicated in a subset of Crohn's disease (CD) patients. We previously stratified clinical outcomes of CD patients by using Paneth cell phenotypes, which we defined by the intracellular distribution of antimicrobial proteins. Animal studies suggest that Paneth cells shape the intestinal microbiome. However, it is unclear whether Paneth cell phenotypes alter the microbiome complexity in CD subjects. Therefore, we analyzed the correlation of Paneth cell phenotypes with mucosal microbiome composition and ileal RNA expression in pediatric CD and noninflammatory bowel disease (non-IBD) patients. METHODS: Pediatric CD (n = 44) and non-IBD (n = 62) patients aged 4 to 18 were recruited prior to routine endoscopic biopsy. Ileal mucosal samples were analyzed for Paneth cell phenotypes, mucosal microbiome composition, and RNA transcriptome. RESULTS: The prevalence of abnormal Paneth cells was higher in pediatric versus adult CD cohorts. For pediatric CD patients, those with abnormal Paneth cells showed significant changes in their ileal mucosal microbiome, highlighted by reduced protective microbes and enriched proinflammatory microbes. Ileal transcriptome profiles showed reduced transcripts for genes that control oxidative phosphorylation in CD patients with abnormal Paneth cells. These transcriptional changes in turn were correlated with specific microbiome alterations. In non-IBD patients, a subset contained abnormal Paneth cells. However, this subset was not associated with alterations in the microbiome or host transcriptome. CONCLUSION: Paneth cell abnormalities in human subjects are associated with mucosal dysbiosis in the context of CD, and these changes are associated with alterations in oxidative phosphorylation, potentially in a feedback loop. FUNDING: The research was funded by Helmsley Charitable Trust (to T.S. Stappenbeck, R.J. Xavier, and D.P.B. McGovern), Crohn's and Colitis Foundation of America (to N.H. Salzman, T.S. Stappenbeck, R.J. Xavier, and C. Huttenhower), and Doris Duke Charitable Foundation grant 2014103 (to T.C. Liu).

Integrative analysis of the microbiome and metabolome of the human intestinal mucosal surface reveals exquisite inter-relationships.

BACKGROUND: Consistent compositional shifts in the gut microbiota are observed in IBD and other chronic intestinal disorders and may contribute to pathogenesis. The identities of microbial biomolecular mechanisms and metabolic products responsible for disease phenotypes remain to be determined, as do the means by which such microbial functions may be therapeutically modified. RESULTS: The composition of the microbiota and metabolites in gut microbiome samples in 47 subjects were determined. Samples were obtained by endoscopic mucosal lavage from the cecum and sigmoid colon regions, and each sample was sequenced using the 16S rRNA gene V4 region (Illumina-HiSeq 2000 platform) and assessed by UPLC mass spectroscopy. Spearman correlations were used to identify widespread, statistically significant microbial-metabolite relationships. Metagenomes for identified microbial OTUs were imputed using PICRUSt, and KEGG metabolic pathway modules for imputed genes were assigned using HUMAnN. The resulting metabolic pathway abundances were mostly concordant with metabolite data. Analysis of the metabolome-driven distribution of OTU phylogeny and function revealed clusters of clades that were both metabolically and metagenomically similar. CONCLUSIONS: The results suggest that microbes are syntropic with mucosal metabolome composition and therefore may be the source of and/or dependent upon gut epithelial metabolites. The consistent relationship between inferred metagenomic function and assayed metabolites suggests that metagenomic composition is predictive to a reasonable degree of microbial community metabolite pools. The finding that certain metabolites strongly correlate with microbial community structure raises the possibility of targeting metabolites for monitoring and/or therapeutically manipulating microbial community function in IBD and other chronic diseases.