Genetic coding variant in complement factor B (CFB) is associated with increased risk for perianal Crohn's disease and leads to impaired CFB cleavage and phagocytosis.

OBJECTIVE: Perianal Crohn's disease (pCD) occurs in up to 40% of patients with CD and is associated with poor quality of life, limited treatment responses and poorly understood aetiology. We performed a genetic association study comparing CD subjects with and without perianal disease and subsequently performed functional follow-up studies for a pCD associated SNP in Complement Factor B (CFB). DESIGN: Immunochip-based meta-analysis on 4056 pCD and 11 088 patients with CD from three independent cohorts was performed. Serological and clinical variables were analysed by regression analyses. Risk allele of rs4151651 was introduced into human CFB plasmid by site-directed mutagenesis. Binding of recombinant G252 or S252 CFB to C3b and its cleavage was determined in cell-free assays. Macrophage phagocytosis in presence of recombinant CFB or serum from CFB risk, or protective CD or healthy subjects was assessed by flow cytometry. RESULTS: Perianal complications were associated with colonic involvement, OmpC and ASCA serology, and serology quartile sum score. We identified a genetic association for pCD (rs4151651), a non-synonymous SNP (G252S) in CFB, in all three cohorts. Recombinant S252 CFB had reduced binding to C3b, its cleavage was impaired, and complement-driven phagocytosis and cytokine secretion were reduced compared with G252 CFB. Serine 252 generates a de novo glycosylation site in CFB. Serum from homozygous risk patients displayed significantly decreased macrophage phagocytosis compared with non-risk serum. CONCLUSION: pCD-associated rs4151651 in CFB is a loss-of-function mutation that impairs its cleavage, activation of alternative complement pathway, and pathogen phagocytosis thus implicating the alternative complement pathway and CFB in pCD aetiology.

Advanced endoscopic resection for colorectal dysplasia in inflammatory bowel disease: a meta-analysis.

Background and study aims Little is known about outcomes of advanced endoscopic resection (ER) for patients with inflammatory bowel disease (IBD) with dysplasia. The aim of our meta-analysis was to estimate the safety and efficacy of endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD) for dysplastic lesions in patients with IBD. Methods We performed a systematic review through Jan 2021 to identify studies of IBD with dysplasia that was treated by EMR or ESD. We estimated the pooled rates of complete ER, adverse events, post-ER surgery, and recurrence. Proportions were pooled by random effect models. Results Eleven studies including 506 patients and 610 lesions were included. Mean lesion size was 23 mm. The pooled rate of complete ER was 97.9 % (95 % confidence interval [CI]: 95.3 % to 99.7 %). The pooled rate of endoscopic perforation was 0.8 % (95 % CI:0.1 % to 2.2 %) while bleeding occurred in 1.6 % of patients (95 %CI:0.4 % to 3.3 %). Overall, 6.6 % of patients (95 %CI:3.6 % to 10.2 %) underwent surgery after an ER. Among 471 patients who underwent surveillance, local recurrence occurred in 4.9 % patients (95 % CI:1.0 % to 10.7 %) and metachronous lesions occurred in 7.4 % patients (95 %CI:1.5 % to 16 %) over a median follow-up of 33 months. Metachronous colorectal cancer (CRC) was detected in 0.2 % of patients (95 %CI:0 % to 2.2 %) during the surveillance period. Conclusions Advanced ER is safe and effective in the management of large dysplastic lesions in IBD and warrants consideration as first-line therapy. Although the risk of developing CRC after ER is low, meticulous endoscopic surveillance is crucial to monitor for local or metachronous recurrence of dysplasia.

Targeted next-generation sequencing supports serrated epithelial change as an early precursor to inflammatory bowel disease-associated colorectal neoplasia.

Serrated epithelial change (SEC) manifests in patients with long-standing inflammatory bowel disease (IBD) and is characterized by disorganized crypt architecture, irregular serrations, and goblet cell-rich epithelium. The serrated nature of SEC is reminiscent of serrated colorectal polyps, which frequently harbor KRAS/BRAF mutations. SEC is, however, not only histologically distinct from sporadic serrated polyps but also associated with colorectal neoplasia. Whether SEC is a precursor to IBD-associated neoplasia remains unclear. To further define the relationship of SEC with serrated colorectal polyps and IBD-associated neoplasia, we performed targeted next-generation sequencing on colorectal specimens to include the following: SEC without dysplasia/neoplasia (n = 10), SEC with separate foci of associated dysplasia/adenocarcinoma from the same patients (n = 17), and uninvolved mucosa (n = 10) from 14 patients. In addition, we molecularly profiled sessile serrated lesion (SSL)-like or serrated lesion, not otherwise specified (SL-NOS), specimens, from 11 patients who also had IBD. This control cohort included SSL-like/SL-NOS without dysplasia/neoplasia (n = 11), SSL-like/SL-NOS with associated low-grade dysplasia (n = 2), and uninvolved mucosa (n = 8). By next-generation sequencing, the most frequently mutated gene in SEC without neoplasia and associated dysplasia/adenocarcinoma from separate foci in the same patients was TP53. Recurrent TP53 mutations were present in 50% of SEC specimens without dysplasia/neoplasia. In addition, alterations in TP53 were detected at a prevalence of 71% in low-grade dysplasia, 83% in high-grade dysplasia, and 100% in adenocarcinoma. Paired sequencing of SEC and associated neoplasia revealed identical TP53 missense mutations for 3 patients. In contrast, 91% of SSL-like/SL-NOS specimens without dysplasia/neoplasia harbored KRAS/BRAF mutations, which were conserved in associated low-grade dysplasia. No genomic alterations were found in uninvolved mucosa from either patients with SEC or patients with SSL-like/SL-NOS. Based on our findings, we conclude SEC is distinct from SSL-like serrated colorectal lesions in patients with IBD and an early precursor to IBD-associated neoplasia that warrants colonoscopic surveillance.

Serrated Epithelial Change Is Associated With High Rates of Neoplasia in Ulcerative Colitis Patients: A Case-controlled Study and Systematic Review With Meta-analysis.

BACKGROUND: Patients with long-standing ulcerative colitis (UC) are at an increased risk of colorectal cancer. Risk stratification is important to identify patients who require more frequent endoscopic surveillance. Serrated epithelial change (SEC) found in patients with long-standing colitis may be associated with neoplasia and serve as a marker to stratify patients at higher risk of colorectal cancer (CRC). METHODS: A case-control study was performed to compare the rates of neoplasia between UC patients with SEC and UC patients without SEC who were matched for age, disease duration, and disease extent. Paired tests, conditional logistic regression, and Kaplan-Meier analyses were used to compare groups. A systematic review with meta-analysis was performed, combining our local data with previously published data. RESULTS: This study included 196 UC patients without prior neoplasia, 98 with SEC and 98 without SEC. Ulcerative colitis patients with SEC had a significantly higher rate of synchronous or metachronous neoplasia than UC patients without SEC (26.5% vs 3.1%; P < 0.001). Synchronous or metachronous high-grade dysplasia and CRC were found more frequently in UC patients with SEC than UC patients without SEC (11.2% vs 2.0%; P = 0.02). A meta-analysis was consistent with these findings, showing a higher rate of neoplasia in patients with SEC compared with those without SEC (16.4% vs 3.9%; P < 0.001). CONCLUSION: Serrated epithelial change is associated with a significantly increased risk of synchronous and metachronous neoplasia including high-grade dysplasia and CRC in patients with UC. Histopathological findings of SEC should warrant closer endoscopic surveillance for CRC.

Refractory inflammatory bowel disease: is there a role for Epstein-Barr virus? A case-controlled study using highly sensitive Epstein-Barr virus-encoded small RNA1 in situ hybridization.

A potential role for viral infections has been implicated in inflammatory bowel disease (IBD) unresponsive to medical treatment. It is well known that Epstein-Barr virus (EBV) infection can elicit a brisk mononuclear response in the gastrointestinal tract. The aim of this study was to further evaluate the role of EBV in patients with refractory IBD and compare them with nonrefractory IBD cases. Surgically resected colonic specimens from 67 patients with refractory IBD (62 with ulcerative colitis, 3 patients with Crohn disease, and 2 patients with indeterminate colitis) were retrieved. Twelve colectomy specimens from patients with ulcerative colitis who had undergone resections for dysplasia or endometriosis were included as controls. Highly sensitive EBV-encoded small RNA1 (EBER-1) in situ hybridization was performed on a representative block from each specimen. EBER-1 reactivity was graded as absent, focal, or diffuse. EBV was detected in 60% (40/67) of patients with refractory IBD compared with 25% (3/12) of the control group (P < .05). Focal EBER-1 positivity was present in 45% of cases of refractory IBD compared with 25% of controls. Diffuse EBER-1 reactivity was seen in 15% of cases of refractory IBD (10/67); none of the samples from the control group contained diffuse EBER-1 positivity. There was a positive correlation between EBER positivity and depth of inflammation and mucosal ulceration in patients with refractory IBD. Our findings suggest a potential role for EBV infection in patients with refractory IBD.

Serrated Colorectal Lesions in Patients With Inflammatory Bowel Disease.

The serrated neoplasia pathway is thought to account for up to 30% of sporadic colorectal cancer, but its role in inflammatory bowel disease (IBD)-related colorectal cancer is still not well elucidated. Hyperplastic polyps are not thought to impart an increased risk of colorectal cancer; however, sessile serrated adenomas/polyps and traditional serrated adenomas may have malignant potential. From the limited research currently available, this appears to hold true for IBD patients as well. IBD patients do not seem to be at a higher risk of typical serrated colorectal lesions than the general population, but it is still not known if they have a quicker progression to colorectal cancer. Serrated epithelial change is a newly described finding in patients with longstanding colitis that may increase the risk of colorectal cancer in IBD patients. Overall, serrated lesions are not uncommon in the IBD population, and further research is needed to understand the role that serrated lesions play in the development of colorectal cancer.

Nearly a Third of High-Grade Dysplasia and Colorectal Cancer Is Undetected in Patients with Inflammatory Bowel Disease.

BACKGROUND: It is unclear whether intensive surveillance protocols have resulted in a decreased incidence of colorectal cancer (CRC) in inflammatory bowel disease (IBD). AIMS: To determine the prevalence and characteristics of IBD associated high-grade dysplasia (HGD) or CRC that was undetected on prior colonoscopy. METHODS: This is a single-center, retrospective study from 1994 to 2013. All participants had a confirmed IBD diagnosis and underwent a colectomy with either HGD or CRC found in the colectomy specimen.The undetected group had no HGD or CRC on prior colonoscopies. The detected group had HGD or CRC identified on previous biopsies. RESULTS: Of 70 participants, with ulcerative colitis (UC) (n = 47), Crohn's disease (CD) (n = 21), and indeterminate colitis (n = 2), 29% (n = 20) had undetected HGD/CRC at colectomy (15 HGD and 5 CRC). In the undetected group, 75% had prior LGD, 15% had indefinite dysplasia, and 10% had no dysplasia (HGD was found in colonic strictures). Patients in the undetected group were more likely to have pancolitis (55 vs. 20%) and multifocal dysplasia (35 vs. 8%). The undetected group was less likely to have CRC at colectomy (25 vs. 62%). There was a trend toward right-sided HGD/CRC at colectomy (40 vs. 20%; p = 0.08). In addition, 84% of the lesions found in the rectum at colectomy were not seen on prior colonoscopy in the undetected group. CONCLUSIONS: The prevalence of previously undetected HGD/CRC in IBD found at colectomy was 29%. The high proportion of undetected rectal and right-sided HGD/CRC suggests that these areas may need greater attention during surveillance.

Colonic ulcerations may predict steroid-refractory course in patients with ipilimumab-mediated enterocolitis.

AIM: To investigate management of patients who develop ipilimumab-mediated enterocolitis, including association of endoscopic findings with steroid-refractory symptoms and utility of infliximab as second-line therapy. METHODS: We retrospectively reviewed all patients at our center with metastatic melanoma who were treated with ipilimumab between March 2011 and May 2014. All patients received a standard regimen of intravenous ipilimumab 3 mg/kg every 3 wk for four doses or until therapy was stopped due to toxicity or disease progression. Basic demographic and clinical data were collected on all patients. For patients who developed grade 2 or worse diarrhea (increase of 4 bowel movements per day), additional data were collected regarding details of gastrointestinal symptoms, endoscopic findings and treatment course. Descriptive statistics were used. RESULTS: A total of 114 patients were treated with ipilimumab during the study period and all were included. Sixteen patients (14%) developed ≥ grade 2 diarrhea. All patients were treated with high-dose corticosteroids (1-2 mg/kg prednisone daily or equivalent). Nine of 16 patients (56%) had ongoing diarrhea despite high-dose steroids. Steroid-refractory patients received one dose of intravenous infliximab at 5 mg/kg, and all but one had brisk resolution of diarrhea. Fourteen of the patients underwent either colonoscopy or sigmoidoscopy with variable endoscopic findings, ranging from mild erythema to colonic ulcers. Among 8 patients with ulcers demonstrated by sigmoidoscopy or colonoscopy, 7 patients (88%) developed steroid-refractory symptoms requiring infliximab. With a median follow-up of 264 d, no major adverse events associated with prednisone or infliximab were reported. CONCLUSION: In patients with ipilimumab-mediated enterocolitis, the presence of colonic ulcers on endoscopy was associated with a steroid-refractory course.

Inflammatory bowel disease associated neoplasia: A surgeon's perspective.

Inflammatory bowel disease (IBD) is associated with increased risk of colorectal cancer (CRC). The risk is known to increase with longer duration of the disease, family history of CRC, and history of primary sclerosing cholangitis. The diagnosis of the neoplastic changes associated with IBD is difficult owing to the heterogeneous endoscopic appearance and inter-observer variability of the pathological diagnosis. Screening and surveillance guidelines have been established which aim for early detection of neoplasia. Several surgical options are available for the treatment of IBD-associated neoplasia. Patients' morbidities, risk factors for CRC, degree and the extent of neoplasia must be considered in choosing the surgical treatment. A multidisciplinary team including the surgeon, gastroenterologist, pathologist, and the patient who has a clear understanding of the nature of their disease is needed to optimize outcomes.

Association between serrated epithelial changes and colorectal dysplasia in inflammatory bowel disease.

BACKGROUND AND AIMS: Serrated epithelial change (SEC) is a histologic finding in longstanding colitis that may be associated with dysplasia. Our primary aim was to determine the incidence of dysplasia and colorectal cancer (CRC) in inflammatory bowel disease (IBD) patients with SEC. Secondary aims were to determine the rate of location concordance between SEC and dysplasia/CRC and to identify other risk factors associated with dysplasia in IBD patients with SEC. METHODS: A retrospective, descriptive, observational study was performed by searching the Pathology Data System at a single tertiary referral center for a histologic finding of "serrated epithelial change." The patient's first pathology specimen with SEC was designated the index SEC. All subsequent pathology reports were evaluated for the occurrence and location of dysplasia or CRC. Univariable and multivariable logistic regression were performed to identify predictors of dysplasia. RESULTS: There were 187 patients with confirmed IBD and 1 or more histologic findings of SEC without prior dysplasia. Mean IBD duration was 16 years, and median follow-up time was 28 months. The rate of high-grade dysplasia or CRC was 17 per 1000 patient-years. Thirty-nine of 187 patients (21%) had synchronous or metachronous dysplasia or CRC. Location concordance was 68%. Multivariable analysis found SEC on follow-up examinations, older age at IBD diagnosis, male gender, and a first-degree relative with CRC were associated with dysplasia in IBD patients with SEC. CONCLUSIONS: This uncontrolled study describes a high frequency of dysplasia in patients with a histologic finding of SEC. SEC seen on successive endoscopic examinations further increased the risk of dysplasia. Further controlled studies are needed to determine if SEC is a precancerous lesion in IBD patients and if SEC can be endoscopically identified.

Optimizing perioperative Crohn's disease management: role of coordinated medical and surgical care.

AIM: To investigate rates of re-establishing gastroenterology care, colonoscopy, and/or initiating medical therapy after Crohn's disease (CD) surgery at a tertiary care referral center. METHODS: CD patients having small bowel or ileocolonic resections with a primary anastomosis between 2009-2012 were identified from a tertiary academic referral center. CD-specific features, medications, and surgical outcomes were abstracted from the medical record. The primary outcome measure was compliance rates with medical follow-up within 4 wk of hospital discharge and surveillance colonoscopy within 12 mo of surgery. RESULTS: Eighty-eight patients met study inclusion criteria with 92% (n=81) of patients returning for surgical follow-up compared to only 41% (n=36) of patients with documented gastroenterology follow-up within four-weeks of hospital discharge, P<0.05. Factors associated with more timely postoperative medical follow-up included younger age, longer length of hospitalization, postoperative biologic use and academic center patients. In the study cohort, 75.0% of patients resumed medical therapy within 12 mo, whereas only 53.4% of patients underwent a colonoscopy within 12 mo of surgery. CONCLUSION: Our study highlights the need for coordinated CD multidisciplinary clinics and structured handoffs among providers to improve of quality of care in the postoperative setting.

The Bacteroides fragilis toxin gene is prevalent in the colon mucosa of colorectal cancer patients.

BACKGROUND: Enterotoxigenic Bacteroides fragilis (ETBF) produces the Bacteroides fragilis toxin, which has been associated with acute diarrheal disease, inflammatory bowel disease, and colorectal cancer (CRC). ETBF induces colon carcinogenesis in experimental models. Previous human studies have demonstrated frequent asymptomatic fecal colonization with ETBF, but no study has investigated mucosal colonization that is expected to impact colon carcinogenesis. METHODS: We compared the presence of the bft gene in mucosal samples from colorectal neoplasia patients (cases, n = 49) to a control group undergoing outpatient colonoscopy for CRC screening or diagnostic workup (controls, n = 49). Single bacterial colonies isolated anaerobically from mucosal colon tissue were tested for the bft gene with touch-down polymerase chain reaction. RESULTS: The mucosa of cases was significantly more often bft-positive on left (85.7%) and right (91.7%) tumor and/or paired normal tissues compared with left and right control biopsies (53.1%; P = .033 and 55.5%; P = .04, respectively). Detection of bft was concordant in most paired mucosal samples from individual cases or controls (75% cases; 67% controls). There was a trend toward increased bft positivity in mucosa from late- vs early-stage CRC patients (100% vs 72.7%, respectively; P = .093). In contrast to ETBF diarrheal disease where bft-1 detection dominates, bft-2 was the most frequent toxin isotype identified in both cases and controls, whereas multiple bft isotypes were detected more frequently in cases (P ≤ .02). CONCLUSIONS: The bft gene is associated with colorectal neoplasia, especially in late-stage CRC. Our results suggest that mucosal bft exposure is common and may be a risk factor for developing CRC.