Efficacy of Dose Escalation of Oral 5-Aminosalicylic Acid for Ulcerative Colitis With a Mayo Endoscopic Subscore of 1: An Open Label Randomized Controlled Trial.

BACKGROUND: Endoscopic healing is generally defined as Mayo endoscopic subscore (MES) ≤1 in ulcerative colitis (UC). However, patients with an MES of 1 are at higher relapse risk than those with an MES of 0. This study evaluated the therapeutic efficacy of proactive dose escalation of oral 5-aminosalicylic acid (5-ASA) in UC patients with an MES of 1. METHODS: An open-label, randomized controlled trial was conducted in 5 hospitals between 2018 and 2022. Ulcerative colitis patients in clinical remission under oral 5-ASA therapy and diagnosed as having an MES of 1 were enrolled. Patients receiving maintenance therapy other than 5-ASA and immunomodulator were excluded. Patients were randomly assigned in a 1:1 ratio to receive either a dose-escalated (intervention) or constant dose (control) of 5-ASA. Concomitant immunomodulator was used as the stratification factor in the randomization. The primary end point was relapse within 1 year. The subgroup analysis was stratified for the use of immunomodulators. RESULTS: The full analysis set included 79 patients (39 intervention and 40 control). Immunomodulators were used in 20 (25.3%) patients. Relapse was less in the intervention group (15.4%) than the control group (37.5%; P = .026). In the subgroup with concomitant immunomodulators, relapse was also less in the intervention group (10.0%) than the control group (70.0%; P = .020). In patients without immunomodulators, the difference was not significant between 2 groups (intervention, 17.2%; control, 26.7%; P = .53). CONCLUSIONS: Dose escalation of 5-ASA reduced relapse within 1 year in UC patients in clinical remission with an MES of 1.

Dose escalation of 5-aminosalicylic acid for ulcerative colitis reduced relapse rate in patients in clinical remission with a Mayo endoscopic subscore of 1. The therapeutic efficacy was more evident in those whom immunomodulators were used.

Leucine-Rich Alpha-2 Glycoprotein May Be Predictive of the Adalimumab Trough Level and Antidrug Antibody Development for Patients with Inflammatory Bowel Disease: A Sub-Analysis of the PLANET Study.

INTRODUCTION: The aim of this study was to examine whether biomarkers are predictive of the adalimumab (ADA) trough level and antidrug antibody development in patients with Crohn's disease (CD) and ulcerative colitis (UC). METHODS: Using data obtained in a prospective, multicenter, observational study (PLANET), we assessed serial changes in a novel biomarker - leucine-rich alpha-2 glycoprotein (LRG) - during ADA treatment for patients with active CD and UC. We measured serum LRG, C-reactive protein (CRP), and fecal calprotectin (fCAL) at weeks 0, 12, 24, and 52. The ADA trough level and anti-ADA antibody (AAA) were also measured at weeks 12 and 52. Correlations between the ADA trough level, AAA, and biomarkers were examined. RESULTS: In all, 34 patients with CD and 47 patients with UC were enrolled. The ADA trough level at week 12 or at the time of ADA withdrawal was 8.5 ± 3.9 in the AAA-negative group (n = 70) and 2.9 ± 2.7 µg/mL in the AAA-positive group (n = 8) (p < 0.0001). The ADA trough level at week 12 or at the time of ADA withdrawal was associated with pretreatment LRG (p = 0.0437 and r = -0.23). CONCLUSION: LRG, rather than CRP or fCAL, may be a marker for predicting the trough level of ADA for patients with CD and UC treated with ADA.

Leucine-rich alpha-2 glycoprotein is a potential biomarker to monitor disease activity in inflammatory bowel disease receiving adalimumab: PLANET study.

BACKGROUND: This multicenter prospective study (UMIN000019958) aimed to evaluate the usefulness of serum leucin-rich alpha-2 glycoprotein (LRG) levels in monitoring disease activity in inflammatory bowel disease (IBD). METHODS: Patients with moderate-to-severe IBD initiated on adalimumab therapy were enrolled herein. Serum LRG, C-reactive protein (CRP), and fecal calprotectin (fCal) levels were measured at week 0, 12, 24, and 52. Colonoscopy was performed at week 0, 12, and 52 for ulcerative colitis (UC), and at week 0, 24, and 52 for Crohn's disease (CD). Endoscopic activity was assessed using the Simple Endoscopic Score for Crohn's Disease (SES-CD) for CD and the Mayo endoscopic subscore (MES) for UC. RESULTS: A total of 81 patients was enrolled. Serum LRG levels decreased along with improvements in clinical and endoscopic outcomes upon adalimumab treatment (27.4 ± 12.6 µg/ml at week 0, 15.5 ± 7.7 µg/ml at week 12, 15.7 ± 9.6 µg/ml at week 24, and 14.5 ± 6.8 µg/ml at week 52), being correlated with endoscopic activity at each time point (SES-CD: r = 0.391 at week 0, r = 0.563 at week 24, r = 0.697 at week 52; MES: r = 0.534 at week 0, r = 0.429 at week 12, r = 0.335 at week 52). Endoscopic activity better correlated with LRG compared to CRP and fCal on pooled analysis at all time points (SES-CD: LRG: r = 0.636, CRP: r = 0.402, fCal: r = 0.435; MES: LRG: r = 0.568, CRP: 0.389, fCal: r = 0.426). CONCLUSIONS: Serum LRG is a useful biomarker of endoscopic activity both in CD and UC during the adalimumab treatment.

Significance of endoscopic deep small bowel evaluation using balloon-assisted enteroscopy for Crohn's disease in clinical remission.

BACKGROUND: Small bowel lesions of Crohn's disease (CD) are known to be associated with a poor prognosis; however, endoscopic healing leads to favorable patients' outcome. The aim of this study was to clarify the clinical impact of assessing deep small bowel lesions (DSB) using balloon-assisted enteroscopy (BAE) on CD patients in clinical remission. METHODS: From January 2012 to July 2018, a total of 100 CD patients in clinical remission were enrolled to undergo trans-anal enteroscopy using single-balloon enteroscope. Endoscopic evaluations at the terminal ileum (TI) were performed using a partial Simple Endoscopic Score for CD (pSES-CD). Endoscopic evaluations at the DSB used a modified partial SES-CD (mpSES-CD). We evaluated the factors associated with relapse, and the correlation of endoscopic score between the TI and DSB. For this study, relapse was defined as hospitalization within a year from enteroscopy. RESULTS: 30 patients (30.0%) relapsed within a year from enteroscopy. Multivariate logistic regression analysis revealed that the Harvey-Bradshaw Index (OR 1.77, 95% CI 1.18-2.65; p = 0.003) and an mpSES-CD at DSB (OR 3.10, 95% CI 1.86-5.15; p = 0.001) were independent predictors for relapse, whereas a SES-CD at the TI did not exhibit independence. There was a significant correlation trend between the relapse rate and greater than 5 points of an mpSES-CD at DSB; however, there was no correlation between the relapse rate and pSES-CD at the TI. CONCLUSION: Even when Crohn's disease is in remission, it is important to evaluate DSB using BAE to assess endoscopic mucosal healing.

Mucosal concentrations of N-acetyl-5-aminosalicylic acid related to endoscopic activity in ulcerative colitis patients with mesalamine.

BACKGROUND AND AIM: 5-Aminosalicylic acid (5-ASA) is a fundamental treatment for mild-to-moderate ulcerative colitis (UC). 5-ASA is taken up into the colonic mucosa and metabolized to N-acetyl-5-ASA (Ac-5-ASA). Few studies have assessed whether mucosal 5-ASA and Ac-5-ASA concentrations are associated with endoscopic remission. This study aimed to investigate differences in 5-ASA and Ac-5-ASA concentrations according to endoscopic activity. METHODS: This single-center, prospective, cross-sectional study was conducted between March 2018 and February 2019. UC patients who were administered with 5-ASA medication for at least 8 weeks before sigmoidoscopy were enrolled. Mucosal 5-ASA and Ac-5-ASA concentrations were measured using liquid chromatography with tandem mass spectrometry. The primary endpoint was defined as the difference in mucosal concentrations of 5-ASA and Ac-5-ASA, according to the Mayo endoscopic subscore (MES). RESULTS: Mucosal concentrations were analyzed in 50 patients. In the sigmoid colon, the median 5-ASA concentration in patients with MES of 0 (17.3 ng/mg) was significantly higher than MES ≥ 1 (6.4 ng/mg) (P = 0.019). The median 5-ASA concentrations in patients with Ulcerative Colitis Endoscopic Index of Severity ≤ 1 (16.4 ng/mg) were also significantly higher than in patients with Ulcerative Colitis Endoscopic Index of Severity ≥ 2 (4.63 ng/mg) (P = 0.047). In the sigmoid colon, the concentration of Ac-5-ASA was higher in patients with MES of 0 (21.2 ng/mg) than in patients with MES ≥ 1 (5.81 ng/mg) (P = 0.022). CONCLUSIONS: The present study showed that mucosal Ac-5-ASA concentrations, as well as 5-ASA concentrations, are higher in UC patients with endoscopic remission. Ac-5-ASA may be useful for a biomarker of 5-ASA efficacy.

5-Aminosalicylic acid intolerance is associated with a risk of adverse clinical outcomes and dysbiosis in patients with ulcerative colitis.

BACKGROUND/AIMS: 5-Aminosalicylic acid (ASA) causes intolerance reactions in some patients. This study was performed to examine the prognosis of patients with ulcerative colitis (UC) and 5-ASA intolerance, and to evaluate the potential interaction between 5-ASA intolerance and the intestinal microbiota. METHODS: We performed a retrospective cohort study of patients with UC who visited participating hospitals. The primary endpoint was to compare the incidence of hospitalization within 12 months between the 5-ASA intolerance group and the 5-ASA tolerance group. The secondary endpoint was to compare the risk of adverse clinical outcomes after the start of biologics between the 2 groups. We also assessed the correlation between 5-ASA intolerance and microbial change in an independently recruited cohort of patients with UC. RESULTS: Of 793 patients, 59 (7.4%) were assigned to the 5-ASA intolerance group and 734 (92.5%) were assigned to the 5-ASA tolerance group. The admission rate and incidence of corticosteroid use were significantly higher in the intolerance than tolerance group (P< 0.001). In 108 patients undergoing treatment with anti-tumor necrosis factor biologics, 5-ASA intolerance increased the incidence of additional induction therapy after starting biologics (P< 0.001). The 5-ASA intolerance group had a greater abundance of bacteria in the genera Faecalibacterium, Streptococcus, and Clostridium than the 5-ASA tolerance group (P< 0.05). CONCLUSIONS: In patients with UC, 5-ASA intolerance is associated with a risk of adverse clinical outcomes and dysbiosis. Bacterial therapeutic optimization of 5-ASA administration may be important for improving the prognosis of patients with UC.

A nationwide, multi-center, retrospective study of symptomatic small bowel stricture in patients with Crohn's disease.

BACKGROUND: Small bowel stricture is one of the most common complications in patients with Crohn's disease (CD). Endoscopic balloon dilatation (EBD) is a minimally invasive treatment intended to avoid surgery; however, whether EBD prevents subsequent surgery remains unclear. We aimed to reveal the factors contributing to surgery in patients with small bowel stricture and the factors associated with subsequent surgery after initial EBD. METHODS: Data were retrospectively collected from surgically untreated CD patients who developed symptomatic small bowel stricture after 2008 when the use of balloon-assisted enteroscopy and maintenance therapy with anti-tumor necrosis factor (TNF) became available. RESULTS: A total of 305 cases from 32 tertiary referral centers were enrolled. Cumulative surgery-free survival was 74.0% at 1 year, 54.4% at 5 years, and 44.3% at 10 years. The factors associated with avoiding surgery were non-stricturing, non-penetrating disease at onset, mild severity of symptoms, successful EBD, stricture length < 2 cm, and immunomodulator or anti-TNF added after onset of obstructive symptoms. In 95 cases with successful initial EBD, longer EBD interval was associated with lower risk of surgery. Receiver operating characteristic analysis revealed that an EBD interval of ≤ 446 days predicted subsequent surgery, and the proportion of smokers was significantly high in patients who required frequent dilatation. CONCLUSIONS: In CD patients with symptomatic small bowel stricture, addition of immunomodulator or anti-TNF and smoking cessation may improve the outcome of symptomatic small bowel stricture, by avoiding frequent EBD and subsequent surgery after initial EBD.

Indigo naturalis is effective even in treatment-refractory patients with ulcerative colitis: a post hoc analysis from the INDIGO study.

BACKGROUND: We recently reported the efficacy of indigo naturalis (IN) in patients with active ulcerative colitis (UC) in a randomized controlled trial (INDIGO study). However, few studies have been conducted to investigate whether IN is effective even in treatment-refractory cases, such as in those with steroid dependency and anti-TNF refractoriness. METHODS: In the INDIGO study, 86 patients with active UC were randomly assigned to an IN group (0.5-2.0 g daily) or placebo group. The rate of clinical response (CR), mucosal healing (MH), and change in fecal calprotectin (FCP) levels was compared between refractory [patients with steroid-dependent disease, previous use of anti-TNF-α, and concomitant use of immunomodulators (IM)] and non-refractory patients. We also analyzed factors predicting CR and MH at week 8. RESULTS: The rates of CR of IN group were significantly higher than placebo group, even in patients with steroid-dependent disease (p < 0.001), previous use of anti-TNF-α (p = 0.002), and concomitant use of IM (p = 0.013). The rates of MH in IN group were significantly higher than in placebo group in patients with steroid-dependent disease (p = 0.009). In the IN group, median FCP levels, at week 8, were significantly lower than baseline in patients with steroid-dependent disease and patients with the previous use of anti-TNF-α (p < 0.001, respectively). Multivariate analysis indicated that the previous use of anti-TNF-α was not a predictive factor for CR and MH at week 8. CONCLUSIONS: In a sub-analysis of data from a randomized placebo-controlled trial, we found that IN may be useful even in patients with steroid-dependent disease and patients with the previous use of anti-TNF-α.

Development of an Indigo Naturalis Suppository for Topical Induction Therapy in Patients with Ulcerative Colitis.

BACKGROUND: Indigo naturalis (IN) consists of ligands for the aryl hydrocarbon receptor and exhibits anti-inflammatory effects. Previously, we demonstrated that an 8-week treatment with oral IN is effective in inducing a clinical response in patients with ulcerative colitis (UC). Some UC patients with proctitis are refractory to topical mesalamine or corticosteroids and therefore require an alternative topical treatment. OBJECTIVES: We aimed to prospectively evaluate the safety and efficacy of IN suppositories in UC patients. METHOD: We performed an open-label, single-center, prospective pilot study from February 2018 to October 2018. A total of 10 patients with active UC, who had moderate to severe inflammation from the rectum to the sigmoid colon, were enrolled. The patients received a daily dose of 50 mg IN suppository for 4 weeks. The primary endpoint was safety at week 4. RESULTS: Although 1 patient experienced anal pain, no serious adverse events were observed. At week 4, the rates of clinical remission and mucosal healing were 30 and 40%, respectively. Mayo rectal bleeding subscores significantly improved after treatment (1.80 ± 0.13 vs. 0.90 ± 0.28; p = 0.009). Approximately 80% of the patients with a baseline Mayo endoscopic subscore in the rectum (r-MES) of 2 achieved mucosal healing, but those with a baseline r-MES of 3 did not. CONCLUSIONS: We found that 4 weeks of IN suppository can be tolerated by UC patients, but its efficacy was limited by the severity of the disease. Further investigation will be needed in order to confirm the optimum dose of IN suppository for patients with UC.

Efficacy of Novel Ultrathin Single-Balloon Enteroscopy for Crohn's Disease: A Propensity Score-Matched Study.

Background/Aims: The evaluation of small bowel lesions of Crohn's disease (CD) using balloon-assisted enteroscopy (BAE) is crucial because mucosal healing is associated with a good prognosis. However, BAE procedures are invasive, requiring sedation or analgesia to reduce the patient's pain. This study evaluated the clinical usefulness of a novel ultrathin single-balloon enteroscopy (SBE) procedure for CD. Methods: This single-center retrospective study included 102 CD patients who underwent trans-anal SBE between January 2012 and May 2018. Of these patients, 82 underwent enteroscopy using conventional SBE, while 20 underwent ultrathin SBE. Patients were analyzed using propensity score matching, with 20 patients per group. The median duration of the examination, terminal ileum intubation rate, median cecum intubation time, median insertion depth, adverse events, and sedated dose in each group were compared. Results: Before propensity score matching, the conventional SBE group had a larger number of surgical history patients than the ultrathin SBE group (p=0.05). After matching, the two groups did not significantly differ clinically. There were no significant differences in the mean duration of the examination, cecum intubation time, or terminal ileal intubation rate between ultrathin SBE and conventional SBE. The mean insertion depth of ultrathin SBE tended to be deeper than that of conventional SBE (p=0.09). The use of ultrathin SBE also reduced the sedative dose during needed for enteroscopy compared with conventional SBE (p=0.005). Conclusions: Novel ultrathin SBE may be less painful for CD patients than conventional SBE.

Factors contributing to the systemic clearance of infliximab with long-term administration in Japanese patients with Crohn's disease: Analysis using population pharmacokinetics
.

OBJECTIVE: Crohn's disease (CD) is a chronic inflammatory gastrointestinal disease with repeated cycles of exacerbation and remission. Infliximab (IFX), a chimeric anti-TNF-α monoclonal antibody, has been widely used for the treatment of CD. However, no study in Japanese CD patients receiving continuous IFX for more than 1 year has been reported. To avoid therapeutic failure during long-term administration in Japanese CD patients, we evaluated the variable factors of IFX pharmacokinetics and the optimal trough IFX concentration at 8 weeks after administration. MATERIALS AND METHODS: Population pharmacokinetic (PPK) analysis was performed using the nonlinear mixed-effect model based on the IFX serum concentration in 832 samples from 121 patients. A one-compartment model was used to examine interindividual variability in the systemic clearance (CL) of intravenously administered IFX. RESULTS: PPK estimates (estimated value, RSE%) were total clearance (CL: 0.018 L/h, 9.1) and volumes of distribution (Vd: 7.35 L, 12.0). Interindividual variability for CL and Vd of 0.11 and 0.16, respectively, was found. Body weight, antibody to IFX (ATI), and albumin level were factors affecting the IFX CL. IFX CL was greater in the ATI-positive than in the ATI-negative group. CL was also greater in nonremission patients. There was a significant association between the predicted serum IFX trough concentration at 8 weeks and therapeutic response with long-term continuous administration (p < 0.05), with a higher concentration at 8 weeks seen in the remission group. CONCLUSION: Using these variables including body weight, ATI, and albumin level, the IFX dose could be calculated for individual CD patients to achieve the optimal therapeutic range.

Intramucosal poorly differentiated and signet-ring cell components in patients with ulcerative colitis-associated high-grade dysplasia.

Despite the rarity of colorectal poorly differentiated adenocarcinoma (Por) and signet-ring cell carcinoma (Sig), they are more frequent in patients with ulcerative colitis (UC). However, little is known about these components of early colitis-associated cancer due to the difficulty of detection at an early stage. Here, we reviewed colitis-associated high-grade dysplasia/cancer with Por/Sig components within the submucosa among 103 lesions of 79 UC patients who presented between 1997 and 2017. In total, one Sig in situ, three intramucosal and two submucosal carcinomas (8.7%) were identified among 69 lesions within the submucosa. Depressed appearance, loss of crypt architecture and amorphous surface pattern suggested the presence of Por/Sig, rather than submucosal infiltration. All lesions were located in the rectosigmoid colon and included high-grade dysplasia. While the surrounding noncancerous mucosa expressed E-cadherin and MUC5AC, the expression of E-cadherin was reduced and the expression of MUC5AC was negative in all of the carcinomas except for the Sig in situ. The gastric type metaplasia associated with altered MUC5AC profiles may be a sign of the stepwise accumulation of molecular alterations, including TP53 defects and a reduced expression level of E-cadherin.

Endoscopic characteristics of small intestinal malignant tumors observed by balloon-assisted enteroscopy.

BACKGROUND: Capsule endoscopy and balloon-assisted enteroscopy (BAE) enable visualization of rare small bowel conditions such as small intestinal malignant tumors. However, details of the endoscopic characteristics of small intestinal malignant tumors are still unknown. AIM: To elucidate the endoscopic characteristics of small intestinal malignant tumors. METHODS: From March 2005 to February 2017, 1328 BAE procedures were performed at Keio University Hospital. Of these procedures, malignant tumors were classified into three groups, Group 1: epithelial tumors including primary small intestinal cancer, metastatic small intestinal cancer, and direct small intestinal invasion by an adjacent organ cancer; Group 2: small intestinal malignant lymphoma; and Group 3, small intestinal gastrointestinal stromal tumors. We systematically collected clinical and endoscopic data from patients' medical records to determine the endoscopic characteristics for each group. RESULTS: The number of patients in each group was 16 (Group 1), 22 (Group 2), and 6 (Group 3), and the percentage of solitary tumors was 100%, 45.5%, and 100%, respectively (P < 0.001). Patients' clinical background parameters including age, symptoms, and laboratory data were not significantly different between the groups. Seventy-five percent of epithelial tumors (Group 1) were located in the upper small intestine (duodenum and ileum), and approximately 70% of gastrointestinal stromal tumors (Group 3) were located in the jejunum. Solitary protruding or mass-type tumors were not seen in malignant lymphoma (Group 2) (P < 0.001). Stenosis was seen more often in Group 1, (68.8%, 27.3%, and 0%; Group 1, 2, and 3, respectively; P = 0.004). Enlarged white villi inside and/or surrounding the tumor were seen in 12.5%, 54.5%, and 0% in Group 1, 2, and 3, respectively (P = 0.001). CONCLUSION: The differential diagnosis of small intestinal malignant tumors could be tentatively made based on BAE findings.

Difference in the clinical characteristic and prognosis of colitis-associated cancer and sporadic neoplasia in ulcerative colitis patients.

BACKGROUND: Although various studies have been conducted on colitis-associated cancer (CAC), few have assessed the differences in the clinical and endoscopic features, treatment, and prognosis of CAC and sporadic neoplasia (SN) in the inflamed mucosa of ulcerative colitis (UC) patients. AIMS: To compare the characteristics of CAC and SN within the previously or currently inflamed mucosa. METHODS: Between 1997 and 2017, we retrospectively analyzed the endoscopic chart data of 348 colonic lesions from 266 UC patients. Non-dysplastic lesions and lesions located outside the inflamed mucosa were excluded. The diagnosis of CAC or SN was confirmed by conventional histopathological and immunohistochemical evaluation of p53 and Ki67. RESULTS: In total, 74 patients with CAC (97 lesions) and 46 with SN (58) were enrolled. The proportions of patients with a younger age of onset of UC, with chronic persistent UC, and with severe inflamed mucosa were significantly higher in the CAC group. In the SN group, no flat lesions were found, whereas 26% of the lesions in the CAC group were flat. Sixteen patients died during a median follow-up of 6.1 years (interquartile range (IQR) 1.8-11.1)in the CAC group, whereas 1 patient died during a median follow-up 3.2 years(IQR 1.4-4.6) in the SN group. Mortality from colorectal cancer was significantly higher (P = 0.015) in the CAC group (12/68; 17.6%) than in the SN group (1/44; 2.3%). The 5-year survival rate was 100% in the SN group and 97% in the CAC group for lesions located in the mucosa or submucosa. CONCLUSION: Recognizing differences in the characteristics of CAC and SN within the inflamed mucosa is critical to avoid unnecessary total colectomy in patients with SN.

Long-term effect of NUDT15 R139C on hematologic indices in inflammatory bowel disease patients treated with thiopurine.

BACKGROUND AND AIM: A missense variant of the nucleoside diphosphate-linked moiety X-type motif 15 (NUDT15) gene (R139C) predisposes Asian patients with inflammatory bowel disease (IBD) to thiopurine-induced leukopenia. This study evaluates the long-term effect of NUDT15 R139C heterozygosity on hematological parameters during thiopurine administration. METHODS: We enrolled 83 Japanese IBD patients who were on anti-tumor necrosis factor-α agents and had used thiopurine. NUDT15 R139C was genotyped by polymerase chain reaction. We retrospectively reviewed patient clinical charts to collect data on white blood cell (WBC) count, mean corpuscular volume (MCV), hemoglobin, and platelet count during the 24 months following thiopurine initiation. RESULTS: The included patients had either Crohn's disease (54; 65.1%) or ulcerative colitis (29; 34.9%). Genotyping of NUDT15 R139C identified 62 patients (74.7%) of genotype C/C and 21 (25.3%) of genotype C/T. The median dose of thiopurine was lower in the C/T group than in the C/C group after starting thiopurine. At 6 months, the mean WBC count of the C/T group became significantly lower than that of the C/C group (P = 0.008) and remained lower through the 24 months. The C/T group developed grade 2-4 leukopenia by 6 months, which persisted through 12-24 months. The mean MCV in the C/T group became higher than that of the C/C group after 3 months. CONCLUSIONS: NUDT15 R139C heterozygosity affected the WBC count and MCV for 24 months after thiopurine administration. Our results indicate that careful monitoring of leukopenia and dose adjustment are necessary throughout treatment in IBD patients heterozygous for the NUDT15 R139C.

Pharmacological effects of TAK-828F: an orally available RORγt inverse agonist, in mouse colitis model and human blood cells of inflammatory bowel disease.

OBJECTIVE AND DESIGN: To evaluate the potency of RORγt blockade for treatment of Inflammatory Bowel Disease (IBD), the efficacy of TAK-828F, a novel RORγt inverse agonist, in anti-TNF-α mAb non-responsive mouse colitis model and effect of TAK-828F on IL-17 production in peripheral mononuclear blood cells (PBMCs) of anti-TNF-α naive and treatment-failure patients of IBD was investigated. METHODS AND RESULTS: The colitis model showed Th17-dependent pathogenicity and response to anti-IL-12/23p40 monoclonal antibody (mAb), but no response to anti-TNF-α mAb. In the model, TAK-828F, at oral dosages of 1 and 3 mg/kg, inhibited progression of colitis and reduced the immune reaction that characterize Th17 cells. Anti-IL-17A mAb showed neither efficacy nor change in the T cell population and colonic gene expression in the model. In the normal mouse, a 4-week treatment of TAK-828F at 30 mg/kg did not severely reduce lymphocyte cell counts in peripheral and intestinal mucosa, which was observed in RORγ-/- mice. TAK-828F strongly inhibited IL-17 gene expression with IC50 values from 21.4 to 34.4 nmol/L in PBMCs from anti-TNF mAb naive and treatment-failure patients of IBD. CONCLUSIONS: These results indicate that RORγt blockade would provide an effective approach for treating refractory patients with IBD by blocking IL-23/Th17 pathway.

Epigenetic regulation of T helper cells and intestinal pathogenicity.

Inflammatory bowel diseases (IBDs) are characterized by relapsing and remitting chronic intestinal inflammation. Previous studies have demonstrated the contributions of genetic background, environmental factors (food, microbiota, use of antibiotics), and host immunity in the development of IBDs. More than 200 genes have been shown to influence IBD susceptibility, most of which are involved in immunity. The vertebrate immune system comprises a complex network of innate and adaptive immune cells that protect the host from infection and cancer. Dysregulation of the mutualistic relationship between the immune system and the gut environment results in IBD. Considering the fundamental role of epigenetic regulation in immune cells, epigenetic mechanisms, particularly in T helper (Th) cells, may play a major role in the complex regulation of mucosal immunity. Epigenetic regulation and dysregulation of Th cells are involved in the maintenance of intestinal homeostasis and its breakdown in IBD.

Clinical utility of novel ultrathin single-balloon enteroscopy: a feasibility study.

BACKGROUND: The advent of balloon-assisted enteroscopy (BAE) has facilitated the examination of the entire digestive tract. However, using a rigid sliding tube during the procedure reduces patient acceptance. This study evaluated the clinical application of a newly developed ultrathin single-balloon enteroscope for BAE. METHODS: 28 outpatients underwent enteroscopy with a novel ultrathin single-balloon enteroscope. None of the subjects required therapeutic procedures, such as balloon dilation or hemostasis. The insertability, efficacy, and safety of the ultrathin single-balloon endoscope were evaluated retrospectively. RESULTS: 7 patients underwent transoral enteroscopy and 21 patients underwent transanal enteroscopy under conscious sedation. No adverse events related to the procedure were reported in any patients. Targeted observation and/or targeted biopsy were achieved in all procedures. All transoral procedures allowed evaluation of the jejunum beyond the ligament of Treitz. All transanal procedures allowed intubation of the terminal ileum, despite several patients having severe stenosis of the colon and ileum. CONCLUSION: A novel ultrathin single-balloon enteroscope showed adequate insertability and safety for outpatient surveillance enteroscopy under conscious sedation.

Efficacy of Therapeutic Intervention for Patients With an Ulcerative Colitis Mayo Endoscopic Score of 1.

BACKGROUND: Mucosal healing (MH) is proposed as a therapeutic target for ulcerative colitis (UC). Recent studies have indicated that the rate of clinical relapse in patients with a Mayo endoscopic score (MES) of 1 is higher than that of patients with an MES of 0. However, no study has yet investigated whether therapeutic intervention prevents clinical relapse in patients with an MES of 1. METHODS: Patients with UC with an MES of 1 and partial Mayo score ≤2 were included in this study. All patients were followed from first colonoscopy (CS) until follow-up CS. Differences in the rate of clinical relapse (requiring additional treatment for UC) or endoscopic exacerbation (MES ≥2 and proximal extension) were compared between the therapeutic intervention (immediately after first CS) group and the nontherapeutic intervention group; risk factors for relapse were also assessed. RESULTS: Among 1523 patients with UC who underwent CS between 2013 and 2016, 220 patients were included in this study. The rate of clinical relapse (P = 0.005) and endoscopic exacerbation (P = 0.11) in patients with therapeutic intervention was lower than that in patients without therapeutic intervention. Multivariable analysis indicated that absence of therapeutic intervention (P = 0.001 for clinical relapse, P = 0.050 for endoscopic exacerbation) and a higher Ulcerative Colitis Endoscopic Index of Severity vascular pattern score immediately after first CS (P = 0.021 for clinical relapse, P = 0.019 for endoscopic exacerbation) were risk factors for both clinical relapse and endoscopic exacerbation. CONCLUSIONS: Therapeutic intervention for patients with UC with an MES of 1 might prevent disease relapse.