Factors Associated with Fibrosis during Colorectal Endoscopic Submucosal Dissection: Does Pretreatment Biopsy Potentially Elicit Submucosal Fibrosis and Affect Endoscopic Submucosal Dissection Outcomes?

BACKGROUND: Submucosal fibrosis observed during colorectal endoscopic submucosal dissection (ESD) is an important factor related to incomplete resection. Biopsy is generally accepted as having the potential to elicit submucosal fibrosis, but few reports have presented definitive proof. This study investigated the relation between submucosal fibrosis and colorectal ESD outcomes and assessed factors related to fibrosis, including pretreatment biopsy. METHODS: After reviewing 369 records of colorectal ESD performed between January 2011 and December 2016, we assessed the relation between fibrosis and ESD outcomes. Multiple logistic regression analysis revealed fibrosis risk factors. RESULTS: Severe fibrosis was related significantly to ESD outcomes such as the mean procedure time (p < 0.001), en bloc resection rate (p < 0.001), and R0 resection rate (p = 0.011). Multivariate analyses indicated residual lesions (ORs 175.4, p < 0.001), pretreatment biopsy (ORs 8.30, p = 0.002), nongranular-type laterally spreading tumors (LST-NG; ORs 5.86, p = 0.025), and invasive carcinoma (ORs 5.83, p = 0.03) as independent risk factors of severe fibrosis. In each macroscopic type, LST-NG was more strongly related to fibrosis induced by pretreatment than granular-type laterally spreading tumors with adjust ORs of 50.8 and 4.69. CONCLUSIONS: Pretreatment biopsy causes submucosal fibrosis resulting in prolonged procedure times and incomplete resection. These findings suggest important benefits of avoiding biopsy before ESD.

Comprehensive Analysis of microRNA Profiles in Organoids Derived from Human Colorectal Adenoma and Cancer.

INTRODUCTION: Exosomes are membrane-enclosed nanovesicles, which are increasingly being recognized as important cell communication components for their role in transmitting microRNAs (miRNAs). No previous study has addressed the exosomal miRNA profile in colorectal adenomas (CRAs) because the long-term culture of CRA is challenging. This study aimed to identify the miRNA signature in organoid exosomes derived from human CRA and colorectal cancer (CRC) samples. METHODS: Organoid cultures were developed from resected colorectal tissues of patients with CRA or CRC undergoing surgery or endoscopic mucosal resection. Exosomes were prepared from the conditioned medium of the organoids. miRNAs were prepared from the exosomes and their source organoids. The miRNA expression profiles were compared using microarray analysis. The impact of alteration of miRNA expression on cell proliferation was examined using miRNA mimics or inhibitors in HT-29 human CRC cells. RESULTS: We established 6 organoid lines from CRC and 8 organoid lines from CRA. Exosomal miRNA signatures were different between the organoids derived from CRA and CRC. Both exosomal and cellular miR-1246 expressions were upregulated in CRC-derived organoids compared to their expression in CRA-derived organoids. Alteration of miR-1246 expression by the miR-1246 mimic or inhibitor increased or decreased cell proliferation in HT-29 cells, respectively. CONCLUSIONS: We report for the first time the miRNA profiles of exosomes in CRA- and CRC-derived organoids. The upregulation of miR-1246 might play a role in increased cell proliferation in the process of CRA-carcinoma transition.

Myeloid ATG16L1 Facilitates Host-Bacteria Interactions in Maintaining Intestinal Homeostasis.

Intact ATG16L1 plays an essential role in Paneth cell function and intestinal homeostasis. However, the functional consequences of ATG16L1 deficiency in myeloid cells, particularly macrophages, are not fully characterized. We generated mice with Atg16l1 deficiency in myeloid and dendritic cells and showed that mice with myeloid Atg16l1 deficiency had exacerbated colitis in two acute and one chronic model of colitis with increased proinflammatory to anti-inflammatory macrophage ratios, production of proinflammatory cytokines, and numbers of IgA-coated intestinal microbes. Mechanistic analyses using primary murine macrophages showed that Atg16l1 deficiency led to increased reactive oxygen species production, impaired mitophagy, reduced microbial killing, impaired processing of MHC class II Ags, and altered intracellular trafficking to the lysosomal compartments. Increased production of reactive oxygen species and reduced microbial killing may be general features of the myeloid compartment, as they were also observed in Atg16l1-deficient primary murine neutrophils. A missense polymorphism (Thr300Ala) in the essential autophagy gene ATG16L1 is associated with Crohn disease (CD). Previous studies showed that this polymorphism leads to enhanced cleavage of ATG16L1 T300A protein and thus reduced autophagy. Similar findings were shown in primary human macrophages from controls and a population of CD patients carrying the Atg16l1 T300A risk variant and who were controlled for NOD2 CD-associated variants. This study revealed that ATG16L1 deficiency led to alterations in macrophage function that contribute to the severity of CD.

Clinical and genetic risk factors for decreased bone mineral density in Japanese patients with inflammatory bowel disease.

BACKGROUND AND AIM: Patients with inflammatory bowel disease (IBD) are at a high risk of low bone mineral density (BMD). Reportedly, clinical and genetic factors cause low BMD in Caucasians; however, studies in non-Caucasian populations remain scarce. METHODS: Clinical risk factors for low BMD were investigated in 266 Japanese patients with IBD, and a genome-wide association analysis (GWAS) was performed using linear regression with associated clinical factors as covariates. Genotyping was performed using a population-optimized genotyping array (Japonica array® ). After quality control, the genotype data of 4 384 682 single-nucleotide polymorphisms (SNPs) from 254 patients with IBD were used for GWAS. RESULTS: Body mass index, age, and disease duration were independently associated with the BMD of the femoral neck (P = 1.41E - 13, 1.04E - 5, and 1.58E - 3, respectively), and body mass index and sex were associated with the BMD of the lumbar spine (P = 6.90E - 10 and 6.84E - 3, respectively). In GWAS, 118 and 42 candidate SNPs of the femoral neck and lumbar spine, respectively, were identified. Among 118, 111 candidate SNPs of the femoral neck were located within the SLC22A23 gene, which is a known IBD susceptibility gene (minimum P = 1.42E - 07). Among 42, 18 candidate SNPs of the lumbar spine were located within the MECOM gene, which is associated with osteopenia (minimum P = 5.86E - 07). Interestingly, none of the known loci showed a significant association with BMD. CONCLUSIONS: Although clinical risk factors for low BMD in IBD were similar to those in the general population, genetic risk factors were rather different.

Tacrolimus Dose Optimization Strategy for Refractory Ulcerative Colitis Based on the Cytochrome P450 3A5 Polymorphism Prediction Using Trough Concentration after 24 Hours.

BACKGROUND: In the tacrolimus treatment for refractory ulcerative colitis (UC), dose adjustment is necessary because the required doses to keep appropriate drug concentrations are significantly different among individuals. Cytochrome P450 (CYP) 3A5 polymorphism affects tacrolimus blood concentrations. However, it is difficult to obtain genetic information in real clinical practice. In the present study, we investigated possible factors that may predict CYP3A5 polymorphism and proposed a dose optimization strategy based on the obtained predicting factors. SUMMARY: We retrospectively analyzed 41 patients who underwent remission induction therapy with tacrolimus for UC in our hospital. First, we performed a correlation analysis of CYP3A5 polymorphism and pharmacokinetics. In the CYP3A5 non-expressers, the dose of tacrolimus (mg/kg) was lower and dose-adjusted trough levels (ng/mL per mg/kg) were higher compared with those in expressers. Next, we investigated factors that could predict CYP3A5 polymorphism. Trough concentration 24 h following tacrolimus administration was extracted as a significant factor. When the trough cutoff value at 24 h was set to 2.6 ng/mL, sensitivity and specificity for estimation of CYP3A5 polymorphism were 63 and 96% respectively. Therefore, when the trough concentration 24 h after administration is ≤2.6 ng/mL, the patient can be estimated as a CYP3A5 expresser and an increase in dose should be proposed. Key Message: The trough concentration 24 h after the first tacrolimus administration appears to be a useful predictor of -CYP3A5 polymorphism. Performing dose optimization strategy based on the prediction of CYP3A5 polymorphism can lead to earlier and safer remission induction.

Protein tyrosine phosphatase SAP-1 protects against colitis through regulation of CEACAM20 in the intestinal epithelium.

Intestinal epithelial cells contribute to regulation of intestinal immunity in mammals, but the detailed molecular mechanisms of such regulation have remained largely unknown. Stomach-cancer-associated protein tyrosine phosphatase 1 (SAP-1, also known as PTPRH) is a receptor-type protein tyrosine phosphatase that is localized specifically at microvilli of the brush border in gastrointestinal epithelial cells. Here we show that SAP-1 ablation in interleukin (IL)-10-deficient mice, a model of inflammatory bowel disease, resulted in a marked increase in the severity of colitis in association with up-regulation of mRNAs for various cytokines and chemokines in the colon. Tyrosine phosphorylation of carcinoembryonic antigen-related cell adhesion molecule (CEACAM) 20, an intestinal microvillus-specific transmembrane protein of the Ig superfamily, was greatly increased in the intestinal epithelium of the SAP-1-deficient animals, suggesting that this protein is a substrate for SAP-1. Tyrosine phosphorylation of CEACAM20 by the protein tyrosine kinase c-Src and the consequent association of CEACAM20 with spleen tyrosine kinase (Syk) promoted the production of IL-8 in cultured cells through the activation of nuclear factor-κB (NF-κB). In addition, SAP-1 and CEACAM20 were found to form a complex through interaction of their ectodomains. SAP-1 and CEACAM20 thus constitute a regulatory system through which the intestinal epithelium contributes to intestinal immunity.

ATP-binding cassette subfamily B member 1 1236C/T polymorphism significantly affects the therapeutic outcome of tacrolimus in patients with refractory ulcerative colitis.

BACKGROUND AND AIM: Tacrolimus is now considered to be one of the main therapeutic options for refractory ulcerative colitis. Both cytochrome P-450 3A5 (CYP3A5) and ATP-binding cassette subfamily B member 1 (ABCB1) associated with tacrolimus metabolism are known to have several genetic polymorphisms. However, it remains controversial whether these polymorphisms affect the therapeutic efficacy for ulcerative colitis. We aimed to investigate the influence of both CYP3A5 and ABCB1 polymorphisms on the efficacy of tacrolimus in ulcerative colitis treatment under the tight dose-adjusting strategy. METHODS: Sixty-one Japanese patients with ulcerative colitis treated with tacrolimus were enrolled retrospectively. Tacrolimus treatment was performed using the tight dose-adjusting strategy. Genotyping for CYP3A5*3, ABCB1 1236C>T, 2677G>A,T, and 3435C>T were performed, and the clinical outcomes at 12 weeks after the initiation of tacrolimus were compared among the genotypes. RESULTS: There was no association between the CYP3A5 genotypes and therapeutic efficacy. In contrast, a significant association was observed with the ABCB1 1236C > T polymorphism and therapeutic efficacy. The ABCB1 1236CC+CT groups (n = 41) had a significantly higher response rate (73% vs 35%; P = 0.004) and remission rate (61% vs 20%; P = 0.002) than the TT group (n = 20). The multivariate logistic regression analysis also revealed that ABCB1 1236C>T was identified as an independent factor associated with remission. CONCLUSIONS: ABCB1 1236C>T polymorphism significantly affects the therapeutic efficacy of tarcolimus at 12 weeks under the tight dose-adjusting treatment for ulcerative colitis.

Usefulness of a peripherally inserted central catheter for total parenteral nutrition in patients with inflammatory bowel disease.

BACKGROUNDS AND AIMS: Peripherally inserted central catheters (PICC) have been widely used as a blood access route for total parenteral nutrition (TPN) in recent years. However, there have been few reports that evaluated the usefulness of PICC for patients with inflammatory bowel disease (IBD). In this study, we compared the clinical courses in patients with IBD who received TPN during their hospitalization by conventional central venous catheters (CVC) and PICC. PATIENTS AND METHODS: A total of 137 IBD patients were enrolled. The CVC group and the PICC group included 56 and 81 patients, respectively. The clinical courses in both groups were compared retrospectively. RESULTS: As a complication of the puncture, pneumothorax occurred in two patients (3.6%) in the CVC group, but in none (0%) in the PICC group. The PICC group had significantly higher rates of achieving the scheduled TPN without removing the catheter, lower rates of catheter-related blood stream infection (CRBSI) and longer periods without CRBSI than the CVC group. CONCLUSION: PICC might be more useful than CVC in terms of safety and the ability to deliver scheduled TPN for IBD patients.

Dendritic cell-specific ablation of the protein tyrosine phosphatase Shp1 promotes Th1 cell differentiation and induces autoimmunity.

Dendritic cells (DCs) promote immune responses to foreign Ags and immune tolerance to self-Ags. Deregulation of DCs is implicated in autoimmunity, but the molecules that regulate DCs to protect against autoimmunity have remained unknown. In this study, we show that mice lacking the protein tyrosine phosphatase Shp1 specifically in DCs develop splenomegaly associated with more CD11c(+) DCs. Splenic DCs from the mutant mice showed upregulation of CD86 and CCR7 expression and of LPS-induced production of proinflammatory cytokines. The mice manifested more splenic Th1 cells, consistent with the increased ability of their DCs to induce production of IFN-γ by Ag-specific T cells in vitro. The number of splenic CD5(+)CD19(+) B-1a cells and the serum concentrations of Igs M and G2a were also increased in the mutant mice. Moreover, aged mutant mice developed glomerulonephritis and interstitial pneumonitis together with increased serum concentrations of autoantibodies. Shp1 is thus a key regulator of DC functions that protects against autoimmunity.

FCGR3A-158 polymorphism influences the biological response to infliximab in Crohn's disease through affecting the ADCC activity.

An association between FCGR3A-158 V/F polymorphism and biological responses to infliximab has been reported in Crohn's disease (CD) in Western countries. However, little is known about the mechanism by which gene polymorphism affects the responses to infliximab. The aims of this study were to confirm the association in Japanese CD patients and to reveal the effect of gene polymorphism on biological responses to infliximab. Japanese CD patients were examined retrospectively at weeks 8 and 30. Clinical and biological responses were assessed by the Crohn's disease activity index and C-reactive protein levels, respectively. The infliximab-binding affinity of natural killer (NK) cells from FCGR3A-158 V/V, V/F and F/F donors was examined. Infliximab-mediated antibody-dependent cell-mediated cytotoxicity (ADCC) activities were also determined using transmembrane TNF-α-expressing Jurkat T cells as target cells and peripheral blood mononuclear cells (PBMCs) from V/V, V/F and F/F donors as effector cells. Biological responses at week 8 were statistically higher in V/V patients, whereas no significant differences were observed in either clinical responses at weeks 8 and 30 or biological responses at week 30 among the three genotypes. NK cells and PBMCs from V/V patients also showed higher infliximab-binding affinity and infliximab-mediated ADCC activity, respectively. Our results suggest that FCGR3A-158 polymorphism is a predicting factor of biological responses to infliximab in the early phases. FCGR3A-158 polymorphism was also found to affect the infliximab-binding affinity of NK cells and infliximab-mediated ADCC activity in vitro, suggesting that an effect on ADCC activity influences biological responses to infliximab in CD patients.

Signal regulatory protein α regulates the homeostasis of T lymphocytes in the spleen.

The molecular basis for formation of lymphoid follicle and its homeostasis in the secondary lymphoid organs remains unclear. Signal regulatory protein α (SIRPα), an Ig superfamily protein that is predominantly expressed in dendritic cells or macrophages, mediates cell-cell signaling by interacting with CD47, another Ig superfamily protein. In this study, we show that the size of the T cell zone as well as the number of CD4(+) T cells were markedly reduced in the spleen of mice bearing a mutant (MT) SIRPα that lacks the cytoplasmic region compared with those of wild-type mice. In addition, the expression of CCL19 and CCL21, as well as of IL-7, which are thought to be important for development or homeostasis of the T cell zone, was markedly decreased in the spleen of SIRPα MT mice. By the use of bone marrow chimera, we found that hematopoietic SIRPα is important for development of the T cell zone as well as the expression of CCL19 and CCL21 in the spleen. The expression of lymphotoxin and its receptor, lymphotoxin ß receptor, as well as the in vivo response to lymphotoxin ß receptor stimulation were also decreased in the spleen of SIRPα MT mice. CD47-deficient mice also manifested phenotypes similar to SIRPα MT mice. These data suggest that SIRPα as well as its ligand CD47 are thus essential for steady-state homeostasis of T cells in the spleen.

Regulation by SIRPα of dendritic cell homeostasis in lymphoid tissues.

The molecular basis for regulation of dendritic cell (DC) development and homeostasis remains unclear. Signal regulatory protein α (SIRPα), an immunoglobulin superfamily protein that is predominantly expressed in DCs, mediates cell-cell signaling by interacting with CD47, another immunoglobulin superfamily protein. We now show that the number of CD11c(high) DCs (conventional DCs, or cDCs), in particular, that of CD8-CD4+ (CD4+) cDCs, is selectively reduced in secondary lymphoid tissues of mice expressing a mutant form of SIRPα that lacks the cytoplasmic region. We also found that SIRPα is required intrinsically within cDCs or DC precursors for the homeostasis of splenic CD4+ cDCs. Differentiation of bone marrow cells from SIRPα mutant mice into DCs induced by either macrophage-granulocyte colony-stimulating factor or Flt3 ligand in vitro was not impaired. Although the accumulation of the immediate precursors of cDCs in the spleen was also not impaired, the half-life of newly generated splenic CD4+ cDCs was markedly reduced in SIRPα mutant mice. Both hematopoietic and nonhematopoietic CD47 was found to be required for the homeostasis of CD4+ cDCs and CD8-CD4- (double negative) cDCs in the spleen. SIRPα as well as its ligand, CD47, are thus important for the homeostasis of CD4+ cDCs or double negative cDCs in lymphoid tissues.

Role of SIRPα in regulation of mucosal immunity in the intestine.

Mononuclear phagocytes such as dendritic cells (DCs) and macrophages in the lamina propria (LP) are thought to be important for both induction of inflammatory responses and maintenance of immunologic tolerance in the mammalian intestine. The molecular mechanisms by which these cells regulate intestinal immunity have remained poorly understood, however. Signal regulatory protein α (SIRPα) is a transmembrane protein that is specifically expressed in DCs, macrophages and neutrophils. Here, we show that SIRPα is abundant in CD11c(+) CD11b(+) LP cells of the mouse intestine. Whereas SIRPα did not appear to be important for the steady-state homeostasis of mucosal immunity in the intestine, the flagellin-stimulated production of IL-17 or interferon (IFN)-γ by LP cells of SIRPα mutant (MT) mice that lack the cytoplasmic region of the protein was markedly decreased compared with that observed with wild-type cells. Moreover, the flagellin-induced production of IL-6 by LP cells from SIRPα MT mice was also greatly reduced. SIRPα MT mice were also resistant to the development of colitis induced by IL-10 deficiency. Our data thus suggest that SIRPα expressed on CD11c(+) LP cells is important for the production of IL-17 or IFN-γ in the LP as well as for the development of colitis induced by IL-10 deficiency.

Liquid Biopsy for Colorectal Adenoma: Is the Exosomal miRNA Derived From Organoid a Potential Diagnostic Biomarker?

INTRODUCTION: MicroRNAs (miRNAs) can serve as tumor biomarkers; however, their role in evaluating colorectal adenoma (CRA) is unclear. Recently, the organoid culture system enabled long-term expansion of human colon epithelium. This study aimed to examine the potential of exosomal miRNAs extracted from CRA organoids as biomarkers in the clinical liquid biopsy CRA test. METHODS: We established organoid cultures from normal colon and CRA using resected specimens. Exosomes were isolated from the conditioned medium organoids. MiRNAs were isolated from the exosomes, and their expression profiles were compared using microarray analysis. To identify miRNA candidates for liquid biopsy, we prospectively compared changes in their expression in serum and exosomes before and after endoscopic resection in 26 patients with CRA. RESULTS: Seven exosomal miRNAs were overexpressed in CRA organoids: miR-4323, miR-4284, miR-1268a, miR-1290, miR-6766-3p, miR-21-5p, and miR-1246. The expression levels of 4 exosomal miRNAs (miR-4323, miR-4284, miR-1290, and miR-1246) and 2 serum miRNAs (miR-1290 and miR-1246) were significantly lower in posttreatment sera. The combined expression of 4 exosomal miRNAs could identify both CRA and large-size (>12.6 cm2) CRA with respective areas under the curve of 0.698 (95% confidence interval [CI] = 0.536-0.823) and 0.834 (95% CI = 0.660-0.929). Combinations of 2-serum miRNA expression values could identify both CRA and large-size CRA with respective area under the curves of 0.691 (95% CI = 0.528-0.817) and 0.834 (95% CI = 0.628-0.938). DISCUSSION: We found that exosomal miRNAs derived from the CRA organoid culture could be potential diagnostic biomarkers for CRA.

Immunoglobulin subtype-coated bacteria are correlated with the disease activity of inflammatory bowel disease.

Immune response involving various immunoglobulin (Ig) isotypes and subtypes to microbiome is involved in the pathogenesis and disease activity of inflammatory bowel diseases (IBDs). To clarify the presence of Ig-coated bacteria in the intestine and its association with disease activity in ulcerative colitis (UC) and Crohn's disease (CD), we extracted and classified Ig-coated bacteria from fecal samples of 42 patients with IBD and 12 healthy controls (HCs) using flow cytometry and 16S ribosomal RNA sequence analysis. The percentage of bacteria coated with IgA and IgM was higher in patients with IBD than in HCs, and IgG-coated bacteria were found only in patients with IBD. Moreover, the percentages of bacteria coated with IgG1, IgG2, IgG3, and IgM in UC samples and IgG3, IgG4, and IgM in CD samples were correlated with disease activities. The proportions of Bacteroides ovatus and Streptococcus increased during the active phase of CD. Hence, the detailed analysis of Ig-coated bacteria and Ig subtypes using flow cytometry could aid in developing useful indicators of disease activity and identifying more disease-related bacteria, which could become novel treatment targets for IBDs.

Localized intestinal AL amyloidosis detected as bright green using autofluorescence endoscopy.

Amyloidosis is classifiable as systemic, with amyloid deposition in organs throughout the body, or localized, involving only one organ. Amyloidosis localized in the intestinal tract is rare. This report describes three cases of localized AL amyloidosis in the intestinal tract and presents their clinical characteristics, endoscopic findings, and prognoses. All three cases were asymptomatic, and were found accidentally during endoscopy for closer examination after a positive fecal occult blood test. Endoscopic findings included patchy redness and meandering dilated vessels of the lesion. Using autofluorescence (AFI) endoscopy, the lesion of amyloid deposition was enhanced as bright green. We used fluorescence microscopy to observe unstained specimens obtained from an amyloid deposition site with excitation light. Autofluorescence was detected with the broad excitation wavelength at amyloid deposition lesion sites of the specimen. Results revealed that AL amyloid has autofluorescence that engenders its detection by AFI endoscopy as bright green. In none of the three cases was systemic amyloidosis or organ failure observed. The long-term course of all the cases was favorable.

Long-Term Prognosis of Japanese Patients with Crohn's Disease Treated by Switching Anti-Tumor Necrosis Factor-α Antibodies.

INTRODUCTION: The long-term prognosis of Japanese patients with Crohn's disease (CD) treated by switching anti-tumor necrosis factor-α (anti-TNFα) antibodies remains unclear. OBJECTIVE: This study aimed to clarify the long-term prognosis and clinical factors that affect the long-term prognosis and outcomes of such patients. METHODS: This retrospective, observational, single-center cohort study analyzed Japanese patients with CD treated by switching between infliximab and adalimumab in the Tohoku University Hospital between March 2003 and December 2017. Cumulative relapse-free survival and cumulative surgery-free survival rates were analyzed using the Kaplan-Meier method. Clinical factors that affected the long-term outcomes were identified using both a log-rank test and the Cox proportional hazards model. RESULTS: The cumulative relapse-free survival rates were 68.6, 33.7, and 22.9% at 1, 3, and 5 years, respectively. The surgery-free survival rates were 91.7, 75.7, and 57.4% at 1, 3, and 5 years, respectively. The cumulative relapse-free survival rate was significantly higher in the group with ileal lesions (HR = 0.12; 95% CI 0.0066-0.64, p = 0.0086), stricture (HR = 0.24; 95% CI 0.0094-0.59, p = 0.0021), and a penetrating type (HR = 0.34; 95% CI 0.14-0.84, p = 0.020). Intolerance (HR = 0.29; 95% CI 0.12-0.63, p = 0.0013) and switching after surgery (HR = 0.41; 95% CI 0.17-0.87, p = 0.019) were clinical factors that reduced the risk of recurrence. The cumulative surgery-free survival rate was significantly higher in the group that switched after surgery (HR = 0.28; 95% CI 0.074-0.91, p = 0.034) and used concomitant thiopurine (HR = 0.32; 95% CI 0.10-0.90, p = 0.030). CONCLUSION: We should clarify the reason for switching anti-TNFα antibodies and investigate bowel complications before switching. Surgical reset of bowel complications including stricture and fistula could reduce the risk of recurrence after switching anti-TNFα antibodies. Concomitant thiopurine administration might reduce the risk of bowel surgery after switching anti-TNFα antibodies.

Endoscopic radial incision and cutting for Crohn's Disease-associated intestinal stricture: a pilot study.

Background and study aims Intestinal stricture associated with Crohn's disease (CD) is usually treated by endoscopic balloon dilation (EBD) or stricture plasty. Although EBD is effective and safe for such strictures, refractory stricture after EBD poses a problem. Hence, other novel approaches for these refractory strictures are required. On the other hand, the efficacy of radial incision and cutting (RIC) method for esophageal stricture after esophagogastric surgery is reported. In this pilot study, we adopted the RIC technique for five CD patients with refractory intestinal stricture to dilate their strictures. We conducted the RIC procedure using an electric needle knife with a ceramic tip on the top of the needle. Four cases were of anastomotic stricture after ileocecal resection and the remaining one case was of stricture due to mucosal healing. The RIC procedure was successful for all five patients. Average procedure time was 18.6 minutes. One patient developed delayed bleeding after RIC. There were no cases of perforation. RIC could be an alternative therapy for intestinal stricture associated with CD. Further studies should be conducted to clarify its efficacy and safety.

Serum C-reactive protein and albumin are useful biomarkers for tight control management of Crohn's disease in Japan.

Tight control management of Crohn's disease (CD) based on biomarkers is more effective than conventional clinical management; however, fecal calprotectin is not allowed in Asian and some Western countries. To investigate whether tight control management based on readily available serum biomarkers results in better outcomes, we retrospectively reviewed treatment courses of consecutive Japanese CD patients treated with anti-tumor necrosis factor agents between 2003 and 2018. The association between failure of tight control (C-reactive protein (CRP) ≥ 0.5 mg/dL or albumin (Alb) < 3.8 g/dL at week 8 or 24) and subsequent major adverse outcomes (MAOs; hospitalization related to CD worsening, surgery, and discontinuation due to treatment failure) were analyzed. Among 223 patients followed for >8 weeks, 88 patients experienced MAOs. Multivariate analysis identified penetrating type, CRP ≥ 0.5 mg/dL and Alb < 3.8 g/dL at week 8 as independent risk factors (hazard ratios: 2.16, 2.06, and 2.08, respectively). Among 204 patients followed for >24 weeks, 80 patients experienced MAOs. Penetrating type, CRP ≥ 0.5 mg/dL, and Alb < 3.8 g/dL at week 24 were identified as independent risk factors (2.39, 1.90, and 2.20, respectively). Even in settings without fecal calprotectin, tight control management based on serum CRP and Alb may help avoid MAOs.