It is well established that the intestinal microbiota plays a key role in the pathogenesis of Crohn's disease (CD) and ulcerative colitis (UC) collectively referred to as inflammatory bowel disease ...(IBD). Epidemiological studies have provided strong evidence that IBD patients bear increased risk for the development of colorectal cancer (CRC). However, the impact of the microbiota on the development of colitis-associated cancer (CAC) remains largely unknown. In this study, we established a new model of CAC using azoxymethane (AOM)-exposed, conventionalized-Il10(-/-) mice and have explored the contribution of the host intestinal microbiota and MyD88 signaling to the development of CAC. We show that 8/13 (62%) of AOM-Il10(-/-) mice developed colon tumors compared to only 3/15 (20%) of AOM- wild-type (WT) mice. Conventionalized AOM-Il10(-/-) mice developed spontaneous colitis and colorectal carcinomas while AOM-WT mice were colitis-free and developed only rare adenomas. Importantly, tumor multiplicity directly correlated with the presence of colitis. Il10(-/-) mice mono-associated with the mildly colitogenic bacterium Bacteroides vulgatus displayed significantly reduced colitis and colorectal tumor multiplicity compared to Il10(-/-) mice. Germ-free AOM-treated Il10(-/-) mice showed normal colon histology and were devoid of tumors. Il10(-/-); Myd88(-/-) mice treated with AOM displayed reduced expression of Il12p40 and Tnfalpha mRNA and showed no signs of tumor development. We present the first direct demonstration that manipulation of the intestinal microbiota alters the development of CAC. The TLR/MyD88 pathway is essential for microbiota-induced development of CAC. Unlike findings obtained using the AOM/DSS model, we demonstrate that the severity of chronic colitis directly correlates to colorectal tumor development and that bacterial-induced inflammation drives progression from adenoma to invasive carcinoma.
A subset of patients who undergo total proctocolectomy with ileal pouch-anal anastomosis (IPAA) creation for ulcerative colitis (UC) will later develop Crohn's disease (CD) of the pouch, which has ...been associated with significant morbidity. We aimed to analyze the incidence of CD of the pouch and to review the existing diagnostic criteria utilized.
A systematic search performed through March 1, 2018, identified 12 studies that reported the incidence of CD of the pouch after IPAA for UC or indeterminate colitis (IC). We compiled all diagnostic criteria utilized in these studies and then performed a meta-analysis using random effects modeling to estimate the overall incidence of CD of the pouch in this population.
Among 4843 patients with an IPAA for UC or IC, 10.3% of patients were ultimately diagnosed with CD of the pouch (95% confidence interval CI, 6.1%-15.4%). The most commonly reported diagnostic criteria were (1) presence of fistula/fistulae, (2) stricture involving the pouch or prepouch ileum, and (3) presence of prepouch ileitis. In a secondary analysis, excluding those studies that included patients with a preoperative diagnosis of IC, the incidence of CD of the pouch was 12.4% (95% CI, 9.0%-16.1%).
The estimated incidence of 10.3% will assist gastroenterologists and surgeons in preoperative counseling regarding the potential to develop CD of the pouch. There is an unmet need for common diagnostic criteria for a more standardized approach to the diagnosis of CD of the pouch.
In vitro data suggest that a subgroup of NLR proteins, including NLRP12, inhibits the transcription factor NF-κB, although physiologic and disease-relevant evidence is largely missing. Dysregulated ...NF-κB activity is associated with colonic inflammation and cancer, and we found Nlrp12−/− mice were highly susceptible to colitis and colitis-associated colon cancer. Polyps isolated from Nlrp12−/− mice showed elevated noncanonical NF-κB activation and increased expression of target genes that were associated with cancer, including Cxcl13 and Cxcl12. NLRP12 negatively regulated ERK and AKT signaling pathways in affected tumor tissues. Both hematopoietic- and nonhematopoietic-derived NLRP12 contributed to inflammation, but the latter dominantly contributed to tumorigenesis. The noncanonical NF-κB pathway was regulated upon degradation of TRAF3 and activation of NIK. NLRP12 interacted with both NIK and TRAF3, and Nlrp12−/− cells have constitutively elevated NIK, p100 processing to p52 and reduced TRAF3. Thus, NLRP12 is a checkpoint of noncanonical NF-κB, inflammation, and tumorigenesis.
► Nlrp12−/− mice are significantly more susceptible to colitis-associated colon cancer ► NLRP12 is a negative regulator NIK, CXCL12, CXCL13, ERK, and AKT in vivo ► Hematopoietic and nonhematopoietic compartments contribute to Nlrp12−/− phenotype ► NLRP12 functionally interacts with and alters the balance of NIK and TRAF3
Anastomotic strictures occur in up to 38% of patients after ileal pouch-anal anastomosis (IPAA). We sought to compare the safety, effectiveness, and durability of mechanical dilation using a Hegar ...dilator to endoscopic through-the-scope balloon dilation (EBD) among IPAA patients with a rectal or ileoanal anastomotic stricture.
We identified adult patients with an IPAA for ulcerative colitis (UC) who underwent a pouchoscopy between January 1, 2015, and December 31, 2019, at a single institution. We compared the effectiveness (median maximum diameter of dilation MMD), safety, and durability of mechanical and balloon dilation using standard statistical comparisons.
A total 74 patients had a stricture at the ileoanal anastomosis and underwent at least 1 mechanical or balloon dilation. The MMD with mechanical dilation was 19 (interquartile range IQR, 18-20) mm for the first dilation and 20 (IQR, 18-20) mm for the second and third dilations. With balloon dilation, the MMD was 12 (IQR, 12-18) mm for the first dilation, 15 (IQR, 12-16.5) mm for the second dilation, and 18 (IQR, 15-18.5) mm for the third dilation. Patients undergoing mechanical dilation experienced a longer duration to second dilation (median 191 days vs 53 days: P < .001), with no difference in complications such as bleeding or perforation noted.
Among patients with ileoanal and rectal strictures, mechanical and balloon approaches to dilation demonstrated similar safety profiles and effectiveness. Mechanical dilation with Hegar dilators appears to be an effective and safe approach to the treatment of distal strictures after IPAA.
Colitis-associated cancer (CAC) is a major complication of inflammatory bowel diseases. We show that components of the inflammasome are protective during acute and recurring colitis and CAC in the ...dextran sulfate sodium (DSS) and azoxymethane + DSS models. Mice lacking the inflammasome adaptor protein PYCARD (ASC) and caspase-1 demonstrate increased disease outcome, morbidity, histopathology, and polyp formation. The increased tumor burden is correlated with attenuated levels of IL-1beta and IL-18 at the tumor site. To decipher the nucleotide-binding domain, leucine-rich-repeat-containing (NLR) component that is involved in colitis and CAC, we assessed Nlrp3 and Nlrc4 deficient mice. Nlrp3(-/-) mice showed an increase in acute and recurring colitis and CAC, although the disease outcome was less severe in Nlrp3(-/-) mice than in Pycard(-/-) or Casp1(-/-) animals. No significant differences were observed in disease progression or outcome in Nlrc4(-/-) mice compared with similarly treated wild-type animals. Bone marrow reconstitution experiments show that Nlrp3 gene expression and function in hematopoietic cells, rather than intestinal epithelial cells or stromal cells, is responsible for protection against increased tumorigenesis. These data suggest that the inflammasome functions as an attenuator of colitis and CAC.
Background & Aims Patients with inflammatory bowel disease (IBD) are at risk for certain malignancies. We aimed to determine the risk of melanoma and nonmelanoma skin cancer (NMSC) in patients with ...IBD and how medications affect these risks. Methods We performed retrospective cohort and nested case-control studies using administrative data from the LifeLink Health Plan Claims Database from 1997 to 2009. The cohort comprised 108,579 patients with IBD, and each was matched to 4 individuals without IBD. The risk of melanoma and NMSC was evaluated by incidence rate ratio (IRR) and by adjusted Cox proportional hazard ratio (HR) modeling. In nested case-control studies, patients with melanoma or NMSC were matched to 4 patients with IBD without melanoma or NMSC. Conditional logistic regression was used to determine associations between medications and both skin cancers. Results In the cohort, IBD was associated with an increased incidence of melanoma (IRR, 1.29; 95% confidence interval CI, 1.09–1.53). Risk was greatest among individuals with Crohn's disease (IRR, 1.45; 95% CI, 1.13–1.85; adjusted HR, 1.28; 95% CI, 1.00–1.64). The incidence of NMSC also increased among patients with IBD (IRR, 1.46; 95% CI, 1.40–1.53) and was greatest among those with CD (IRR, 1.64; 95% CI, 1.54–1.74). In the nested case-control studies, therapy with biologics increased the risk of melanoma (odds ratio OR, 1.88; 95% CI, 1.08–3.29). Patients who had been treated with thiopurines had an increased risk of NMSC (OR, 1.85; 95% CI, 1.66–2.05). Conclusions Immunosuppression increases the risk of melanoma and NMSC among patients with IBD. The risk of melanoma is increased by use of biologics, and the risk of NMSC is increased by use of thiopurines. Patients with IBD should be counseled and monitored for skin cancer.
Crohn's disease (CD) of the pouch and chronic pouchitis occur in approximately 10% of patients after ileal pouch-anal anastomosis (IPAA) for refractory ulcerative colitis (UC) or UC-related ...dysplasia. The efficacy of anti-tumor necrosis factor (anti-TNF) agents and vedolizumab have been reported for the treatment of CD of the pouch and chronic pouchitis, but little is known regarding the use of ustekinumab in these settings. Our primary aim was to evaluate the efficacy of ustekinumab for these conditions.
This is a retrospective, multicenter cohort study evaluating the efficacy of ustekinumab in patients with CD of the pouch and chronic pouchitis. Clinical response or remission was judged by the treating physician's assessment at 6 months.
Fifty-six patients (47 with CD of the pouch and 9 with chronic pouchitis) were included the study. Of these, 73% had previously been treated with either anti-TNF therapy, vedolizumab, or both after IPAA. Among patients with CD of the pouch and chronic pouchitis, 83% demonstrated clinical response 6 months after induction with ustekinumab. Responders demonstrated significantly less pouch inflammation on endoscopy when compared with nonresponders (29% vs 100%; P = 0.023). Higher mean body mass index at induction (26.3 vs 23.7; P = 0.033) and male sex (83% vs 30%; P = 0.014) were significant predictors of nonresponse to ustekinumab in those with CD of the pouch.
In this refractory patient population, ustekinumab appears to be a safe and effective treatment for chronic pouchitis and CD of the pouch in biologic-naïve patients and those with prior anti-TNF or vedolizumab therapy failure. 10.1093/ibd/izx005_video1 izy302.video1 5844889626001.
Current knowledge regarding the epidemiology of pouchitis is based on highly selected, mostly single-center, patient cohorts. Our objective was to prospectively determine the population-based ...incidence of pouchitis in patients with ulcerative colitis in the first 2 years after ileal pouch-anal anastomosis and analyze time trends of the incidence of pouchitis.
Using national registries, we established a population-based cohort of all Danish patients undergoing proctocolectomy with ileal pouch-anal anastomosis for ulcerative colitis between 1996 and 2018. The primary outcome was the development of pouchitis within the first 2 years after surgery, evaluated by time period. We used Kaplan-Meier and Cox proportional hazard modeling to evaluate the time to development of pouchitis.
Overall, 1664 patients underwent an ileal pouch-anal anastomosis. The cumulative incidence of pouchitis in the 2 years after ileal pouch-anal anastomosis increased throughout the study period, from 40% in the period from 1996 to 2000 (95% CI, 35%-46%) to 55% in the period from 2015 to 2018 (95% CI, 48%-63%). Patients undergoing surgery between 2015 and 2018 also showed an increased risk of pouchitis compared with the earliest study period (1996-2000) after adjusting for sex, age, and socioeconomic status (hazard ratio, 1.57; 95% CI, 1.20-2.05).
This population-based study showed a 15% absolute and 38% relative increase in the incidence of pouchitis among patients undergoing surgery between 1996 and 2018, with the greatest cumulative incidence of pouchitis shown in the most recent era (2015-2018). The striking increase in the incidence of pouchitis highlights the need for further research into causes and prevention of pouchitis.
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