The Xenobiotic Transporter Mdr1 Enforces T Cell Homeostasis in the Presence of Intestinal Bile Acids.

CD4+ T cells are tightly regulated by microbiota in the intestine, but whether intestinal T cells interface with host-derived metabolites is less clear. Here, we show that CD4+ T effector (Teff) cells upregulated the xenobiotic transporter, Mdr1, in the ileum to maintain homeostasis in the presence of bile acids. Whereas wild-type Teff cells upregulated Mdr1 in the ileum, those lacking Mdr1 displayed mucosal dysfunction and induced Crohn's disease-like ileitis following transfer into Rag1-/- hosts. Mdr1 mitigated oxidative stress and enforced homeostasis in Teff cells exposed to conjugated bile acids (CBAs), a class of liver-derived emulsifying agents that actively circulate through the ileal mucosa. Blocking ileal CBA reabsorption in transferred Rag1-/- mice restored Mdr1-deficient Teff cell homeostasis and attenuated ileitis. Further, a subset of ileal Crohn's disease patients displayed MDR1 loss of function. Together, these results suggest that coordinated interaction between mucosal Teff cells and CBAs in the ileum regulate intestinal immune homeostasis.

Healthy First-Degree Relatives From Multiplex Families vs Simplex Families Have a Higher Subclinical Intestinal Inflammation, a Distinct Fecal Microbial Signature, and Harbor a Higher Risk of Developing Crohn's Disease.

BACKGROUND & AIMS: Unaffected first-degree relatives (FDRs) from families with ≥2 affected FDRs with Crohn's disease (CD, multiplex families) have a high risk of developing CD, although the underlying mechanisms driving this risk are poorly understood. We aimed to identify differences in biomarkers between FDRs from multiplex vs simplex families and investigate the risk of future CD onset accounting for potential confounders. METHODS: We assessed the Crohn's and Colitis Canada Genetic Environmental Microbial cohort of healthy FDRs of patients with CD. Genome-wide CD-polygenic risk scores, urinary fractional excretion of lactulose-to-mannitol ratio, fecal calprotectin (FCP), and fecal 16S ribosomal RNA microbiome were measured at recruitment. Associations between CD multiplex status and baseline biomarkers were determined using generalized estimating equations models. Cox models were used to assess the risk of future CD onset. RESULTS: There were 4051 participants from simplex families and 334 from CD multiplex families. CD multiplex status was significantly associated with higher baseline FCP (P = .026) but not with baseline CD-polygenic risk scores or the lactulose-to-mannitol ratio. Three bacterial genera were found to be differentially abundant between both groups. CD multiplex status at recruitment was independently associated with an increased risk of developing CD (adjusted hazard ratio, 3.65; 95% confidence interval, 2.18-6.11, P < .001). CONCLUSION: Within FDRs of patients with CD, participants from multiplex families had a 3-fold increased risk of CD onset, a higher FCP, and an altered bacterial composition, but not genetic burden or altered gut permeability. These results suggest that putative environmental factors might be enriched in FDRs from multiplex families.

Whole-genome sequencing of African Americans implicates differential genetic architecture in inflammatory bowel disease.

Whether or not populations diverge with respect to the genetic contribution to risk of specific complex diseases is relevant to understanding the evolution of susceptibility and origins of health disparities. Here, we describe a large-scale whole-genome sequencing study of inflammatory bowel disease encompassing 1,774 affected individuals and 1,644 healthy control Americans with African ancestry (African Americans). Although no new loci for inflammatory bowel disease are discovered at genome-wide significance levels, we identify numerous instances of differential effect sizes in combination with divergent allele frequencies. For example, the major effect at PTGER4 fine maps to a single credible interval of 22 SNPs corresponding to one of four independent associations at the locus in European ancestry individuals but with an elevated odds ratio for Crohn disease in African Americans. A rare variant aggregate analysis implicates Ca2+-binding neuro-immunomodulator CALB2 in ulcerative colitis. Highly significant overall overlap of common variant risk for inflammatory bowel disease susceptibility between individuals with African and European ancestries was observed, with 41 of 241 previously known lead variants replicated and overall correlations in effect sizes of 0.68 for combined inflammatory bowel disease. Nevertheless, subtle differences influence the performance of polygenic risk scores, and we show that ancestry-appropriate weights significantly improve polygenic prediction in the highest percentiles of risk. The median amount of variance explained per locus remains the same in African and European cohorts, providing evidence for compensation of effect sizes as allele frequencies diverge, as expected under a highly polygenic model of disease.

Higher Intra-Abdominal Visceral Adipose Tissue Mass Is Associated With Lower Rates of Clinical and Endoscopic Remission in Patients With Inflammatory Bowel Diseases Initiating Biologic Therapy: Results of the Constellation Study.

BACKGROUND & AIMS: We sought to assess the association between intra-abdominal visceral adipose tissue (IA-VAT) and response to 3 different biologic drugs in patients with inflammatory bowel disease (IBD) and to investigate its effects on inflammatory cytokine expression, pharmacokinetics, and intestinal microbiota. METHODS: We prospectively enrolled subjects with active IBD initiating infliximab, vedolizumab, or ustekinumab and a healthy control group. Baseline body composition (including IA-VAT as percent of total body mass [IA-VAT%]) was measured using GE iDXA scan. Primary outcome was corticosteroid- free deep remission at weeks 14-16, defined as Harvey Bradshaw Index <5 for Crohn's disease and partial Mayo score <2 for ulcerative colitis, with a normal C-reactive protein and fecal calprotectin. Secondary outcomes were corticosteroid-free deep remission and endoscopic remission (Endoscopic Mayo Score ≤1 in ulcerative colitis or Simple Endoscopic Score for Crohn's disease ≤2) at weeks 30-46. RESULTS: A total of 141 patients with IBD and 51 healthy controls were included. No differences in body composition parameters were seen between the IBD and healthy control cohorts. Patients with higher IA-VAT% were less likely to achieve corticosteroid-free deep remission (P < .001) or endoscopic remission (P = .02) vs those with lower IA-VAT%. Furthermore, nonresponders with high IA-VAT% had significantly higher serum interleukin-6 and tumor necrosis factor at baseline compared with responders and patients with low IA-VAT%. Drug pharmacokinetic properties and microbiota diversity were similar when comparing high and low IA-VAT% groups. CONCLUSIONS: Higher IA-VAT% was independently associated with worse outcomes. This association could be driven at least partially by discrete differences in inflammatory cytokine expression.

Early Life and Childhood Environmental Exposures, More Than Genetic Predisposition, Influence Age of Diagnosis in a Diverse Cohort of 2952 Patients With IBD.

BACKGROUND AND AIMS: Inflammatory bowel disease (IBD) develops from a combination of genetic and environmental factors. The aim of this study was to determine the contribution of established environmental risk factors and genetic risk on age of IBD diagnosis in a diverse cohort. METHODS: IBD patients in clinic completed detailed questionnaires. Blood was drawn for genetic analysis. Environmental risk factors and age of diagnosis were analyzed by ethnicity (Hispanic/Latinx or non-Hispanic White [NHW] individuals) and IBD subtype (ulcerative colitis or Crohn's disease [CD]). Weighted genetic risk scores and environmental risk scores were developed. We examined the relationship between environmental risk scores, genetic risk scores, and age of diagnosis. RESULTS: A total of 2952 patients were included: 58.9% had CD. A total of 46.83% were of Hispanic background. Early life exposures like cesarean delivery and being born in a developed country were associated with a younger age of IBD diagnosis. Childhood exposures such as frequent plastic water bottle use and having more than 1 bathroom at home were associated with a younger age of IBD. Hispanic and NHW individuals shared similar susceptibilities to environmental exposures. Environmental factors explained 21% of the variance in age of CD diagnosis and 39% in ulcerative colitis. In models incorporating genetic risk score and environmental risk score, the environment was the only significant factor associated with younger age of IBD diagnosis in all groups. CONCLUSIONS: Early life and childhood exposures impact IBD diagnosis and influence Hispanic and NHW individuals similarly. A cumulative environmental risk score contributes more to age of IBD diagnosis than genetic risk.

Ancestral Diversity in Pharmacogenomics Affects Treatment for Hispanic/Latine Populations With Inflammatory Bowel Disease.

BACKGROUND AND AIMS: The prevalence of inflammatory bowel disease among Hispanic/Latine communities is increasing. Pharmacogenomic studies reveal genetic markers that influence treatment decisions. The aim of our study was to examine the frequency and impact of genetic polymorphisms on thiopurine-associated leukopenia (NUDT15, TPMT) and anti-tumor necrosis factor (TNF) immunogenicity (HLA-DQA1∗05) in a cohort of Hispanic patients of diverse ancestral backgrounds. METHODS: We performed a multicenter, retrospective cohort study comprising 2225 Hispanic participants. We measured the frequency of variation affecting drug response in NUDT15, TPMT, and HLA-DQA1∗05; their ancestral origin (European, African, or Amerindian); and the rate of development of myelosuppression and immunogenicity to thiopurines and anti-TNFs, in exposed patients. RESULTS: NUDT15 and TPMT variants were rare, except for rs116855232 in NUDT15, which was common only in alleles of Amerindian origin. All NUDT15 variant alleles were inherited on an Amerindian haplotype, and among the Amerindian allele subset, the variant frequency of NUDT15∗4 (rs147390019) was a remarkable 23% in patients with leukopenia but only 3% in patients without leukopenia. HLA-DQA1∗05 and its European tagging variant rs2097432 were common in alleles from all ancestral origins and demonstrated association with immunogenicity to anti-TNFs. However, rs2097432 was only correlated with HLA-DQA1∗05 in the European allele subset. CONCLUSIONS: These findings indicate that NUDT15 testing should become standard clinical practice before prescribing thiopurines in individuals with Amerindian/Alaska Native ancestry, including Hispanic individuals. Additionally, rs2097432 should not be used as a surrogate for HLA-DQA1∗05 testing for diverse populations. Ultimately, incorporating ancestry in personalized therapeutic approaches is important for treatment of Hispanic patients with inflammatory bowel disease.

Environmental Factors Associated With Risk of Crohn's Disease Development in the Crohn's and Colitis Canada - Genetic, Environmental, Microbial Project.

BACKGROUND & AIMS: To date, it is unclear how environmental factors influence Crohn's disease (CD) risk and how they interact with biological processes. This study investigates the association between environmental exposures and CD risk and evaluates their association with pre-disease biomarkers. METHODS: We studied 4289 healthy first-degree relatives (FDRs) of patients with CD from the Crohn's and Colitis Canada - Genetic, Environmental, Microbial (CCC-GEM) project. Regression models identified environmental factors associated with future CD onset and their association with pre-disease biological factors, including altered intestinal permeability measured by urinary fractional excretion of lactulose to mannitol ratio (LMR); gut inflammation via fecal calprotectin (FCP) levels; and fecal microbiome composition through 16S rRNA sequencing. RESULTS: Over a 5.62-year median follow-up, 86 FDRs developed CD. Living with a dog between ages 5 and 15 (hazard ratio [HR], 0.62; 95% confidence interval [CI], 0.40-0.96; P = .034), and living with a large family size in the first year of life (HR, 0.43; 95% CI, 0.21-0.85; P = .016) were associated with decreased CD risk, whereas having a bird at the time of recruitment (HR, 2.78; 95% CI, 1.36-5.68; P = .005) was associated with an increased CD risk. Furthermore, living with a dog was associated with reduced LMR, altered relative abundance of multiple bacterial genera, and increased Chao1 diversity, whereas bird owners had higher FCP levels. Large family during participants' first year of life was associated with altered microbiota composition without affecting FCP or LMR. CONCLUSION: This study identifies environmental variables associated with CD risk. These variables were also associated with altered barrier function, subclinical inflammation, and gut microbiome composition shifts, suggesting potential roles in CD pathogenesis.

Efficacy and Safety of Ustekinumab for Ulcerative Colitis Through 4 Years: Final Results of the UNIFI Long-Term Maintenance Study.

INTRODUCTION: Ulcerative colitis (UC) is a chronic condition that may require long-term treatment. We report the final efficacy and safety results of the UNIFI long-term extension study of ustekinumab in patients with UC through 4 years. METHODS: Ustekinumab induction responders who completed 44 weeks of maintenance treatment and agreed to enter the long-term extension continued their subcutaneous maintenance therapy (90 mg ustekinumab every 8 or 12 weeks [q8w or q12w] or placebo). Starting at week 56, randomized patients could receive dose adjustment to 90 mg q8w. Symptoms and adverse events were assessed through the study; endoscopic assessment was conducted at week 200. RESULTS: Of the 348 patients randomized to subcutaneous ustekinumab at maintenance baseline (q8w and q12w combined), 55.2% were in symptomatic remission at week 200. A greater proportion of biologic-naive patients (67.2% [117/174]) were in symptomatic remission than those with a history of biologic failure (41.6% [67/161]). Among patients in symptomatic remission at week 200, 96.4% were corticosteroid-free. Of the 171 patients with endoscopic evaluation at week 200, 81.6% (71/87) in the q12w group and 79.8% (67/84) in the q8w group had endoscopic improvement. From weeks 156 to the final safety visit (up to week 220), no deaths, major adverse cardiovascular events, or tuberculosis occurred in patients receiving ustekinumab. Nasopharyngitis, UC worsening, and upper respiratory tract infections were the most frequently reported adverse events. DISCUSSION: The long-term efficacy of ustekinumab maintenance in patients with UC was confirmed through 4 years. No new safety signals were observed. ClinicalTrials.gov number NCT02407236.

The Relationship Between Loneliness, Social Isolation, and Inflammatory Bowel Disease: A Narrative Review.

BACKGROUND: There is clear evidence that loneliness and social isolation have profound health consequences. Documenting the associations of loneliness and social isolation with inflammatory bowel disease (IBD) symptoms, disease severity, and treatment outcomes could meaningfully improve health and quality of life in patients with IBD. PURPOSE: The purpose of this narrative review was to synthesize the empirical evidence on the associations of loneliness and social isolation with IBD symptoms, disease severity, and treatment outcomes. METHODS: Articles were identified through systematic database searches. Quantitative studies that enrolled patients with IBD were included if they examined one of the following outcomes: (a) loneliness or social isolation or (b) IBD-related symptoms, disease severity, or treatment outcomes. RESULTS: We identified 1,816 articles after removing duplicates. Of the 18 studies that met the inclusion criteria, 15 were cross-sectional and 3 were longitudinal. Overall, studies found that loneliness was associated with greater disease activity, functional gastrointestinal symptoms, IBD illness stigma, depressive symptoms, daily IBD symptom burden, reduced resilience, and poorer quality of life. Social isolation was associated with higher prevalence of IBD hospitalizations, premature mortality, and depression. CONCLUSIONS: Findings suggest that loneliness and social isolation are associated with poorer health and quality of life in patients with IBD. Prospective cohort studies examining the biobehavioral mechanisms accounting for the associations of loneliness and social isolation with IBD-related outcomes are needed to guide the development of psychological interventions for individuals living with IBD.

This article explores the connection between loneliness, social isolation, and health outcomes in people with inflammatory bowel disease (IBD). While loneliness and social isolation are known to negatively impact health in other chronic diseases, their specific effects within IBD have been far less studied. This study conducted a narrative review and found that loneliness is linked to more severe IBD symptoms, including increased disease activity, greater gastrointestinal distress, and lower quality of life. Similarly, social isolation is associated with higher rates of IBD-related hospitalizations, depression, and reduced coping abilities. These findings highlight the importance of addressing loneliness and social isolation in patients with IBD. Doing so may be key to developing psychological interventions that improve the well-being and health of those living with IBD.

Pattern Recognition Receptor Signaling and Cytokine Networks in Microbial Defenses and Regulation of Intestinal Barriers: Implications for Inflammatory Bowel Disease.

Inflammatory bowel disease is characterized by defects in epithelial function and dysregulated inflammatory signaling by lamina propria mononuclear cells including macrophages and dendritic cells in response to microbiota. In this review, we focus on the role of pattern recognition receptors in the inflammatory response as well as epithelial barrier regulation. We explore cytokine networks that increase inflammation, regulate paracellular permeability, cause epithelial damage, up-regulate epithelial proliferation, and trigger restitutive processes. We focus on studies using patient samples as well as speculate on pathways that can be targeted to more holistically treat patients with inflammatory bowel disease.

Combination Therapy With Immunomodulators Improves the Pharmacokinetics of Infliximab But Not Vedolizumab or Ustekinumab.

BACKGROUND AND AIMS: The aim of this study was to assess how 6-thioguanine nucleotide (6-TGN) levels and use of oral methotrexate relate to the pharmacokinetics of biologics. METHODS: This was a prospective cohort study including patients with inflammatory bowel diseases on maintenance doses of infliximab, vedolizumab, or ustekinumab on monotherapy or combination with a thiopurine or oral methotrexate. We collected 6-TGN concentrations, biomarker levels, and clinical and endoscopic disease activity. The primary outcomes were infliximab, vedolizumab, and ustekinumab concentrations as well as anti-drug antibodies (ADAs). RESULTS: A total of 369 patients were recruited (113 infliximab, 133 vedolizumab, and 123 ustekinumab). Patients with 6-TGN levels ≥146 pmol per 8 × 108 red blood cells (RBCs), and those receiving combination therapy with thiopurine or oral methotrexate had significantly higher infliximab concentrations when compared with monotherapy (median levels of 17.4 µg/mL on thiopurine with 6-TGN ≥146 pmol per 8 × 108 RBCs, 17.1 on methotrexate, and 3.9 on infliximab monotherapy; P = .001 for both comparisons). However, there was no association between the use of immunomodulators and 6-TGN concentrations with vedolizumab (median levels of 8.8 on thiopurine with 6-TGN ≥152 pmol per 8 × 108 RBCs, 6.8 on methotrexate, and 10.5 on vedolizumab monotherapy; P > .05 for both comparisons) or ustekinumab median concentrations (median levels of 5.0 on thiopurine with 6-TGN ≥154 pmol per 8 × 108 RBCs, 5.2 on methotrexate and 7.0 on ustekinumab monotherapy; P > .05 for both comparisons). Fourteen (12%) patients had anti-infliximab antibodies, while 1 patient had ADAs in each of the other drug cohorts. CONCLUSIONS: Achieving higher 6-TGN levels or the use of methotrexate improved the pharmacokinetics of infliximab. Conversely, these data do not support the use of combination therapy to augment pharmacokinetics with vedolizumab or ustekinumab.

Mediterranean-Like Dietary Pattern Associations With Gut Microbiome Composition and Subclinical Gastrointestinal Inflammation.

BACKGROUND & AIMS: Case-control studies have shown that patients with Crohn's disease (CD) have a microbial composition different from healthy individuals. Although the causes of CD are unknown, epidemiologic studies suggest that diet is an important contributor to CD risk, potentially via modulation of bacterial composition and gut inflammation. We hypothesized that long-term dietary clusters (DCs) are associated with gut microbiome compositions and gut inflammation. Our objectives were to identify dietary patterns and assess whether they are associated with alterations in specific gut microbial compositions and subclinical levels of gut inflammation in a cohort of healthy first-degree relatives (FDRs) of patients with CD. METHODS: As part of the Genetic, Environmental, Microbial (GEM) Project, we recruited a cohort of 2289 healthy FDRs of patients with CD. Individuals provided stool samples and answered a validated food frequency questionnaire reflecting their habitual diet during the year before sample collection. Unsupervised analysis identified 3 dietary and 3 microbial composition clusters. RESULTS: DC3, resembling the Mediterranean diet, was strongly associated with a defined microbial composition, with an increased abundance of fiber-degrading bacteria, such as Ruminococcus, as well as taxa such as Faecalibacterium. The DC3 diet was also significantly associated with lower levels of subclinical gut inflammation, defined by fecal calprotectin, compared with other dietary patterns. No significant associations were found between individual food items and fecal calprotectin, suggesting that long-term dietary patterns rather than individual food items contribute to subclinical gut inflammation. Additionally, mediation analysis demonstrated that DC3 had a direct effect on subclinical inflammation that was partially mediated by the microbiota. CONCLUSIONS: Overall, these results indicated that Mediterranean-like dietary patterns are associated with microbiome and lower intestinal inflammation. This study will help guide future dietary strategies that affect microbial composition and host gut inflammation to prevent diseases.

Altered Gut Microbiome Composition and Function Are Associated With Gut Barrier Dysfunction in Healthy Relatives of Patients With Crohn's Disease.

BACKGROUND & AIMS: The gut microbiome has been suggested to play a role in gut barrier hemostasis, but data are scarce and limited to animal studies. We therefore aimed to assess whether alterations in gut microbial composition and functional pathways are associated with gut barrier function in a cohort of healthy first-degree relatives of patients with Crohn's disease. METHODS: We used the Crohn's and Colitis Canada Genetic Environmental Microbial (CCC-GEM) cohort of healthy first-degree relatives of patients with Crohn's disease. Gut barrier function was assessed using the urinary fractional excretion of lactulose-to-mannitol ratio (LMR). Microbiome composition was assessed by sequencing fecal 16S ribosomal RNA. The cohort was divided into a discovery cohort (n = 2472) and a validation cohort (n = 655). A regression model was used to assess microbial associations with the LMR. A random forest classifier algorithm was performed to assess microbial community contribution to barrier function. RESULTS: Individuals with impaired barrier function (LMR >0.025) had reduced alpha-diversity (Chao1 index, P = 4.0e-4) and altered beta-diversity (Bray-Curtis dissimilarity index, R2 = 0.001, P = 1.0e-3) compared with individuals with an LMR ≤0.025. When taxa were assessed individually, we identified 8 genera and 52 microbial pathways associated with an LMR >0.025 (q < 0.05). Four genera (decreased prevalence of Adlercreutzia, Clostridia UCG 014, and Clostridium sensu stricto 1 and increased abundance of Colidextribacter) and 8 pathways (including decreased biosynthesis of glutamate, tryptophan, and threonine) were replicated in the validation cohort. The random forest approach revealed that the bacterial community is associated with gut barrier function (area under the curve, 0.63; P = 1.4e-6). CONCLUSIONS: The gut microbiome community and pathways are associated with changes in gut barrier function. These findings may identify potential microbial targets to modulate gut barrier.

Global Hospitalization Trends for Crohn's Disease and Ulcerative Colitis in the 21st Century: A Systematic Review With Temporal Analyses.

BACKGROUND & AIMS: The evolving epidemiologic patterns of inflammatory bowel disease (IBD) throughout the world, in conjunction with advances in therapeutic treatments, may influence hospitalization rates of IBD. We performed a systematic review with temporal analysis of hospitalization rates for IBD across the world in the 21st century. METHODS: We systematically reviewed Medline and Embase for population-based studies reporting hospitalization rates for IBD, Crohn's disease (CD), or ulcerative colitis (UC) in the 21st century. Log-linear models were used to calculate the average annual percentage change (AAPC) with associated 95% confidence intervals (95% CIs). Random-effects meta-analysis pooled country-level AAPCs. Data were stratified by the epidemiologic stage of a region: compounding prevalence (stage 3) in North America, Western Europe, and Oceania vs acceleration of incidence (stage 2) in Asia, Eastern Europe, and Latin America vs emergence (stage 1) in developing countries. RESULTS: Hospitalization rates for a primary diagnosis of IBD were stable in countries in stage 3 (AAPC, -0.13%; 95% CI, -0.72 to 0.97), CD (AAPC, 0.20%; 95% CI, -1.78 to 2.17), and UC (AAPC, 0.02%; 95% CI, -0.91 to 0.94). In contrast, hospitalization rates for a primary diagnosis were increasing in countries in stage 2 for IBD (AAPC, 4.44%; 95% CI, 2.75 to 6.14), CD (AAPC, 8.34%; 95% CI, 4.38 to 12.29), and UC (AAPC, 3.90; 95% CI, 1.29 to 6.52). No population-based studies were available for developing regions in stage 1 (emergence). CONCLUSIONS: Hospitalization rates for IBD are stabilizing in countries in stage 3, whereas newly industrialized countries in stage 2 have rapidly increasing hospitalization rates, contributing to an increasing burden on global health care systems.

Patients With Inflammatory Bowel Diseases and Higher Visceral Adipose Tissue Burden May Benefit From Higher Infliximab Concentrations to Achieve Remission.

INTRODUCTION: In patients with inflammatory bowel diseases (IBDs), high visceral adipose tissue (VAT) burden is associated with a lower response to infliximab, potentially through alterations in volume distribution and/or clearance. Differences in VAT may also explain the heterogeneity in target trough levels of infliximab associated with favorable outcomes. The aim of this study was to assess whether VAT burden may be associated with infliximab cutoffs associated with efficacy in patients with IBD. METHODS: We conducted a prospective cross-sectional study of patients with IBD receiving maintenance infliximab therapy. We measured baseline body composition parameters (Lunar iDXA), disease activity, trough levels of infliximab, and biomarkers. The primary outcome was steroid-free deep remission. The secondary outcome was endoscopic remission within 8 weeks of infliximab level measurement. RESULTS: Overall, 142 patients were enrolled. The optimal trough levels of infliximab cutoffs associated with steroid-free deep remission and endoscopic remission were 3.9 mcg/mL (Youden Index [J]: 0.52) for patients in the lowest 2 VAT % quartiles (<1.2%) while optimal infliximab level cutoffs associated with steroid-free deep remission for those patients in the highest 2 VAT % quartiles was 15.3 mcg/mL (J: 0.63). In a multivariable analysis, only VAT % and infliximab level remained independently associated with steroid-free deep remission (odds ratio per % of VAT: 0.3 [95% confidence interval: 0.17-0.64], P < 0.001 and odds ratio per µg/mL: 1.11 [95% confidence interval: 1.05-1.19], P < 0.001). DISCUSSION: The results may suggest that patients with higher visceral adipose tissue burden may benefit from achieving higher infliximab levels to achieve remission.

Ustekinumab as Induction and Maintenance Therapy for Ulcerative Colitis.

BACKGROUND: The efficacy of ustekinumab, an antagonist of the p40 subunit of interleukin-12 and interleukin-23, as induction and maintenance therapy in patients with ulcerative colitis is unknown. METHODS: We evaluated ustekinumab as 8-week induction therapy and 44-week maintenance therapy in patients with moderate-to-severe ulcerative colitis. A total of 961 patients were randomly assigned to receive an intravenous induction dose of ustekinumab (either 130 mg [320 patients] or a weight-range-based dose that approximated 6 mg per kilogram of body weight [322]) or placebo (319). Patients who had a response to induction therapy 8 weeks after administration of intravenous ustekinumab were randomly assigned again to receive subcutaneous maintenance injections of 90 mg of ustekinumab (either every 12 weeks [172 patients] or every 8 weeks [176]) or placebo (175). The primary end point in the induction trial (week 8) and the maintenance trial (week 44) was clinical remission (defined as a total score of ≤2 on the Mayo scale [range, 0 to 12, with higher scores indicating more severe disease] and no subscore >1 [range, 0 to 3] on any of the four Mayo scale components). RESULTS: The percentage of patients who had clinical remission at week 8 among patients who received intravenous ustekinumab at a dose of 130 mg (15.6%) or 6 mg per kilogram (15.5%) was significantly higher than that among patients who received placebo (5.3%) (P<0.001 for both comparisons). Among patients who had a response to induction therapy with ustekinumab and underwent a second randomization, the percentage of patients who had clinical remission at week 44 was significantly higher among patients assigned to 90 mg of subcutaneous ustekinumab every 12 weeks (38.4%) or every 8 weeks (43.8%) than among those assigned to placebo (24.0%) (P = 0.002 and P<0.001, respectively). The incidence of serious adverse events with ustekinumab was similar to that with placebo. Through 52 weeks of exposure, there were two deaths (one each from acute respiratory distress syndrome and hemorrhage from esophageal varices) and seven cases of cancer (one each of prostate, colon, renal papillary, and rectal cancer and three nonmelanoma skin cancers) among 825 patients who received ustekinumab and no deaths and one case of cancer (testicular cancer) among 319 patients who received placebo. CONCLUSIONS: Ustekinumab was more effective than placebo for inducing and maintaining remission in patients with moderate-to-severe ulcerative colitis. (Funded by Janssen Research and Development; UNIFI ClinicalTrials.gov number, NCT02407236.).

Patients With Low Drug Levels or Antibodies to a Prior Anti-Tumor Necrosis Factor Are More Likely to Develop Antibodies to a Subsequent Anti-Tumor Necrosis Factor.

Therapeutic drug monitoring (TDM) with measurement of serum drug and antidrug antibodies (ADAb) is used widely to confirm therapeutic exposure, rule out immunogenicity, and optimize treatment of biologics in patients with inflammatory bowel diseases.1 A recent genome-wide association study found the variant HLA-DQA1∗05 to increase the risk of development of antibodies against infliximab (IFX) and adalimumab (ADM) 2-fold, regardless of concomitant immunomodulator use.2,3 However, there is currently limited evidence showing whether patients who develop antibodies to 1 anti-tumor necrosis factor (TNF) are prone to develop antibodies to the subsequent anti-TNF. Our aim was to investigate the risk of subsequent antibody development in cases (with ADAb to prior anti-TNF) versus control subjects (without ADAb to prior anti-TNF) using a large cohort of patients with inflammatory bowel diseases who underwent TDM with a drug-tolerant assay.

Early Symptomatic Improvement After Ustekinumab Therapy in Patients With Ulcerative Colitis: 16-Week Data From the UNIFI Trial.

BACKGROUND & AIMS: Rapid symptomatic relief is an important treatment goal for patients with ulcerative colitis (UC). We aimed to characterize early response with ustekinumab in patients with moderate-to-severe UC during the initial 16 weeks of treatment. METHODS: We performed a post hoc analysis of data from A Study to Evaluate the Safety and Efficacy of Ustekinumab Induction and Maintenance Therapy in Participants With Moderately to Severely Active Ulcerative Colitis trial. Patients (N = 961) were randomized (1:1:1) to receive intravenous 130 mg ustekinumab, approximately 6 mg/kg ustekinumab, or placebo at week 0. Symptomatic remission, absolute stool number, Mayo stool frequency and rectal bleeding subscores, partial Mayo score, C-reactive protein, and fecal calprotectin were assessed in the overall population and for patients in the biologic-naïve or prior biologic failure subgroups. RESULTS: A significantly greater percentage of patients in the 130-mg ustekinumab (20.0%; P = .015) or approximately 6-mg/kg ustekinumab (20.2%; P = .012) groups achieved symptomatic remission at week 2 vs placebo (12.9%). Mean [SD] changes from baseline in daily stool number on day 7 were greater in the ustekinumab groups (-1.1 [2.6] in 130 mg [P = .065] and -1.2 [2.5] in ∼6 mg/kg [P = .017]) vs placebo (-0.7 [2.7]). The percentage of patients with Mayo stool frequency subscore of 1 or less and rectal bleeding subscore of 0 increased from baseline through week 16 for both ustekinumab groups. Significant improvements in partial Mayo scores were observed by week 2 in both ustekinumab groups vs placebo (P ≤ .001). Significantly more patients in the ustekinumab groups had normalized C-reactive protein levels from week 2 to week 8 vs placebo (P ≤ .05). Similar results were observed with normalized fecal calprotectin levels between week 2 and week 4 (P ≤ .05). CONCLUSIONS: Ustekinumab improved symptoms in patients with UC compared with placebo in as early as 7 days, indicating rapid onset of effect after induction. CLINICAL TRIAL REGISTRY NUMBER: ClinicalTrials.gov: NCT02407236.

Epithelial TLR4 Signaling Activates DUOX2 to Induce Microbiota-Driven Tumorigenesis.

BACKGROUND & AIMS: Chronic colonic inflammation leads to dysplasia and cancer in patients with inflammatory bowel disease. We have described the critical role of innate immune signaling via Toll-like receptor 4 (TLR4) in the pathogenesis of dysplasia and cancer. In the current study, we interrogate the intersection of TLR4 signaling, epithelial redox activity, and the microbiota in colitis-associated neoplasia. METHODS: Inflammatory bowel disease and colorectal cancer data sets were analyzed for expression of TLR4, dual oxidase 2 (DUOX2), and NADPH oxidase 1 (NOX1). Epithelial production of hydrogen peroxide (H2O2) was analyzed in murine colonic epithelial cells and colonoid cultures. Colorectal cancer models were carried out in villin-TLR4 mice, carrying a constitutively active form of TLR4, their littermates, and villin-TLR4 mice backcrossed to DUOXA-knockout mice. The role of the TLR4-shaped microbiota in tumor development was tested in wild-type germ-free mice. RESULTS: Activation of epithelial TLR4 was associated with up-regulation of DUOX2 and NOX1 in inflammatory bowel disease and colorectal cancer. DUOX2 was exquisitely dependent on TLR4 signaling and mediated the production of epithelial H2O2. Epithelial H2O2 was significantly increased in villin-TLR4 mice; TLR4-dependent tumorigenesis required the presence of DUOX2 and a microbiota. Mucosa-associated microbiota transferred from villin-TLR4 mice to wild-type germ-free mice caused increased H2O2 production and tumorigenesis. CONCLUSIONS: Increased TLR4 signaling in colitis drives expression of DUOX2 and epithelial production of H2O2. The local milieu imprints the mucosal microbiota and imbues it with pathogenic properties demonstrated by enhanced epithelial reactive oxygen species and increased development of colitis-associated tumors. The inter-relationship between epithelial reactive oxygen species and tumor-promoting microbiota requires a 2-pronged strategy to reduce the risk of dysplasia in colitis patients.