Development of antifibrotic therapy for stricturing Crohn's disease: lessons from randomized trials in other fibrotic diseases.

Intestinal fibrosis is considered an inevitable complication of Crohn's disease (CD) that results in symptoms of obstruction and stricture formation. Endoscopic or surgical treatment is required to treat the majority of patients. Progress in the management of stricturing CD is hampered by the lack of effective antifibrotic therapy; however, this situation is likely to change because of recent advances in other fibrotic diseases of the lung, liver, and skin. In this review, we summarize data from randomized controlled trials (RCTs) of antifibrotic therapies in these conditions. Multiple compounds have been tested for antifibrotic effects in other organs. According to their mechanisms, they were categorized into growth factor modulators, inflammation modulators, 5-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase inhibitors, intracellular enzymes and kinases, renin-angiotensin system (RAS) modulators, and others. From our review of the results from the clinical trials and discussion of their implications in the gastrointestinal tract, we have identified several molecular candidates that could serve as potential therapies for intestinal fibrosis in CD.

Special issue "The advance of solid tumor research in China": Prediction of Sunitinib efficacy using computed tomography in patients with pancreatic neuroendocrine tumors.

Clinically effective methods to predict the efficacy of sunitinib, for patients with metastatic or locally advanced pancreatic neuroendocrine tumors (panNET) are scarce, making precision treatment difficult. This study aimed to develop and validate a computed tomography (CT)-based method to predict the efficacy of sunitinib in patients with panNET. Pretreatment CT images of 171 lesions from 38 patients with panNET were included. CT value ratio (CT value of tumor/CT value of abdominal aorta from the same patient) and radiomics features were extracted for model development. Receiver operating curve (ROC) with area under the curve (AUC) and decision curve analysis (DCA) were used to evaluate the proposed model. Tumor shrinkage of >10% at first follow-up after sunitinib treatment was significantly associated with longer progression-free survival (PFS; P < .001) and was used as the major treatment outcome. The CT value ratio could predict tumor shrinkage with AUC of 0.759 (95% confidence interval [CI], 0.685-0.833). We then developed a radiomics signature, which showed significantly higher AUC in training (0.915; 95% CI, 0.866-0.964) and validation (0.770; 95% CI, 0.584-0.956) sets than CT value ratio. DCA also confirmed the clinical utility of the model. Subgroup analysis showed that this radiomics signature had a high accuracy in predicting tumor shrinkage both for primary and metastatic tumors, and for treatment-naive and pretreated tumors. Survival analysis showed that radiomics signature correlated with PFS (P = .020). The proposed radiomics-based model accurately predicted tumor shrinkage and PFS in patients with panNET receiving sunitinib and may help select patients suitable for sunitinib treatment.

Upadacitinib as induction and maintenance therapy for moderately to severely active ulcerative colitis: results from three phase 3, multicentre, double-blind, randomised trials.

BACKGROUND: There is a great unmet need for advanced therapies that provide rapid, robust, and sustained disease control for patients with ulcerative colitis. We assessed the efficacy and safety of upadacitinib, an oral selective Janus kinase 1 inhibitor, as induction and maintenance therapy in patients with moderately to severely active ulcerative colitis. METHODS: This phase 3, multicentre, randomised, double-blind, placebo-controlled clinical programme consisted of two replicate induction studies (U-ACHIEVE induction [UC1] and U-ACCOMPLISH [UC2]) and a single maintenance study (U-ACHIEVE maintenance [UC3]). The studies were conducted across Europe, North and South America, Australasia, Africa, and the Asia-Pacific region at 199 clinical centres in 39 countries (UC1), 204 clinical centres in 40 countries (UC2), and 195 clinical centres in 35 countries (UC3). Patients aged 16-75 years with moderately to severely active ulcerative colitis (Adapted Mayo score 5-9; endoscopic subscore 2 or 3) for at least 90 days were randomly assigned (2:1) to oral upadacitinib 45 mg once daily or placebo for 8 weeks (induction studies). Patients who achieved clinical response following 8-week upadacitinib induction were re-randomly assigned (1:1:1) to upadacitinib 15 mg, upadacitinib 30 mg, or placebo for 52 weeks (maintenance study). All patients were randomly assigned using web-based interactive response technology. The primary endpoints were clinical remission per Adapted Mayo score at week 8 (induction) and week 52 (maintenance). The efficacy analyses in the two induction studies were based on the intent-to-treat population, which included all randomised patients who received at least one dose of treatment. In the maintenance study, the primary efficacy analyses reported in this manuscript were based on the first 450 (planned) clinical responders to 8-week induction therapy with upadacitinib 45 mg once daily. The safety analysis population in the induction studies consisted of all randomised patients who received at least one dose of treatment; in the maintenance study, this population included all patients who received at least one dose of treatment as part of the primary analysis population. These studies are registered at ClinicalTrials.gov, NCT02819635 (U-ACHIEVE) and NCT03653026 (U-ACCOMPLISH). FINDINGS: Between Oct 23, 2018, and Sept 7, 2020, 474 patients were randomly assigned to upadacitinib 45 mg once daily (n=319) or placebo (n=155) in UC1. Between Dec 6, 2018, and Jan 14, 2021, 522 patients were randomly assigned to upadacitinib 45 mg once daily (n=345) or placebo (n=177) in UC2. In UC3, a total of 451 patients (21 from the phase 2b study, 278 from UC1, and 152 from UC2) who achieved a clinical response after 8 weeks of upadacitinib induction treatment were randomly assigned again to upadacitinib 15 mg (n=148), upadacitinib 30 mg (n=154), and placebo (n=149) in the primary analysis population. Statistically significantly more patients achieved clinical remission with upadacitinib 45 mg (83 [26%] of 319 patients in UC1 and 114 [34%] of 341 patients in UC2) than in the placebo group (seven [5%] of 154 patients in UC1 and seven [4%] of 174 patients; p<0·0001; adjusted treatment difference 21·6% [95% CI 15·8-27·4] for UC1 and 29·0% [23·2-34·7] for UC2). In the maintenance study, clinical remission was achieved by statistically significantly more patients receiving upadacitinib (15 mg 63 [42%] of 148; 30 mg 80 [52%] of 154) than those receiving placebo (18 [12%] of 149; p<0·0001; adjusted treatment difference 30·7% [21·7-39·8] for upadacitinib 15 mg vs placebo and 39·0% [29·7-48·2] for upadacitinib 30 mg vs placebo). The most commonly reported adverse events in UC1 were nasopharyngitis (15 [5%] of 319 in the upadacitinib 45 mg group vs six [4%] of 155 in the placebo group), creatine phosphokinase elevation (15 [4%] vs three [2%]), and acne (15 [5%] vs one [1%]). In UC2, the most frequently reported adverse event was acne (24 [7%] of 344 in the upadacitinib 45 mg group vs three [2%] of 177 in the placebo group). In both induction studies, serious adverse events and adverse events leading to discontinuation of treatment were less frequent in the upadacitinib 45 mg group than in the placebo group (serious adverse events eight [3%] vs nine (6%) in UC1 and 11 [3%] vs eight [5%] in UC2; adverse events leading to discontinuation six [2%] vs 14 [9%] in UC1 and six [2%] vs nine [5%] in UC2). In UC3, the most frequently reported adverse events (≥5%) were worsening of ulcerative colitis (19 [13%] of 148 in the upadacitinib 15 mg group vs 11 [7%] of 154 in the upadacitinib 30 mg group vs 45 [30%] of 149 in the placebo group), nasopharyngitis (18 [12%] vs 22 [14%] vs 15 [10%]), creatine phosphokinase elevation (nine [6%] vs 13 [8%] vs three [2%]), arthralgia (nine [6%] vs five [3%] vs 15 [10%]), and upper respiratory tract infection (seven [5%] vs nine [6%] vs six [4%]). The proportion of serious adverse events (ten [7%] vs nine [6%] vs 19 [13%]) and adverse events leading to discontinuation (six [4%] vs ten [6%] vs 17 [11%]) was lower in both upadacitinib groups than in the placebo group. Events of cancer, adjudicated major adverse cardiac events, or venous thromboembolism were reported infrequently. There were no treatment-related deaths. INTERPRETATION: Upadacitinib demonstrated a positive efficacy and safety profile and could be an effective treatment option for patients with moderately to severely active ulcerative colitis. FUNDING: AbbVie.

Efficacy of Biologic Drugs in Short-Duration Versus Long-Duration Inflammatory Bowel Disease: A Systematic Review and an Individual-Patient Data Meta-Analysis of Randomized Controlled Trials.

BACKGROUND AND AIMS: Starting biologic treatment early in the course of inflammatory bowel disease (IBD) may be associated with higher efficacy, especially in Crohn's disease (CD). METHODS: This was a systematic review and individual-patient data meta-analysis of all placebo-controlled trials of biologics approved for IBD at study inception (October 2015), using Vivli data-sharing platform. The primary outcome was the proportional biologic/placebo treatment effect on induction of remission in patients with short-duration (≤18 months) vs long-duration disease (>18 months) analyzed separately for CD and ulcerative colitis (UC). We used meta-regression to examine the impact of patients' characteristics on the primary outcome. RESULTS: We included 25 trials, testing infliximab, adalimumab, certolizumab, golimumab, natalizumab, or vedolizumab (6168 patients with CD and 3227 patients with UC). In CD, remission induction rates were higher in pooled placebo and patients in active arms with short-duration disease of ≤18 months (41.4% [244 of 589]) compared with disease duration of >18 months (29.8% [852 of 2857], meta-analytically estimated odds ratio, 1.33; 95% confidence interval, 1.09-1.64). The primary outcome, proportional biologic/placebo treatment effect on induction of remission, was not different in short-duration disease of ≤18 months (n = 589, odds ratio, 1.47; 95% confidence interval, 1.01-2.15) compared with longer disease duration (n = 2857, odds ratio, 1.43; 95% confidence interval, 1.19-1.72). In UC trials, both the proportional biologic/placebo remission-induction effect and the pooled biologic-placebo effect were stable, regardless of disease duration. Primary outcome results remained unchanged when tested using alternative temporal cutoffs and when modeled for individual patient's covariates, including prior anti-tumor necrosis factor exposure. CONCLUSIONS: There are higher rates of induction of remission with biologics and with placebo in early CD, resulting in a treatment to placebo effect ratio that is similar across disease durations. No such relationships between disease duration and outcomes was found in UC. PROSPERO registration: CRD42018041961.

The role of quantitative tumor burden based on [68 Ga]Ga-DOTA-NOC PET/CT in well-differentiated neuroendocrine tumors: beyond prognosis.

PURPOSE: We aimed to elucidate the role of quantitative tumor burden based on PET/CT of somatostatin receptors in well-differentiated neuroendocrine tumors (NETs). METHODS: This study enrolled patients with [68 Ga]Ga-DOTA-NOC PET/CT-positive advanced NETs who did not receive medical treatment prior to PET/CT. Tumor burden was calculated using methods based on the background threshold and relative fixed threshold values (30%, 40%, and 50%). The prognostic value of the measured tumor burden in reference to overall survival (OS) and progression-free survival (PFS) on treatment with octreotide long-acting repeatable (LAR) was assessed using Cox regression analysis, Harrell's C-index, and survival analysis. A classification and regression tree (CART) was used to determine the optimal threshold for tumor burden. RESULTS: A total of 204 patients were included. Somatostatin receptor-expressing tumor volume (SRETV) and liver SRETV derived from a relative fixed threshold of 30% (SRETV30 and liver SRETV30) were statistically significantly associated with OS (C-index: 0.802 [95% confidence interval (CI), 0.658-0.946] and 0.806 [95% CI, 0.664-0.948], respectively). Extrahepatic tumor burden was not correlated with OS (hazard ratio: 0.617, 95% CI: 0.241-1.574, P = 0.312). Among 155 patients with non-functional NETs with a ki-67 index of ≤ 10%, those with a high SRETV30 (P = 0.016) or high liver SRETV30 (P = 0.014) showed statistically significantly worse PFS on treatment with octreotide LAR. Patients receiving a higher dose of octreotide LAR normalized by SRETV30 or liver SRETV30 (a normalized dose or a liver normalized dose) showed prolonged PFS on treatment with octreotide LAR and a prolonged OS. CONCLUSION: Quantitative tumor burden based on [68 Ga]Ga-DOTA-NOC PET/CT was correlated with OS and PFS in patients with non-functional NETs with a ki-67 index of ≤ 10% who received octreotide LAR. Calculating normalized and liver normalized doses may help in selecting the starting dose of octreotide LAR.

Asia-Pacific guidelines for managing functional dyspepsia overlapping with other gastrointestinal symptoms.

Contemporary systems for the diagnosis and management gastrointestinal symptoms not attributable to organic diseases (Functional GI Disorders, FGID, now renamed Disorders of Gut-Brain Interaction, DGBI) seek to categorize patients into narrowly defined symptom-based sub-classes to enable targeted treatment of patient cohorts with similar underlying putative pathophysiology. However, an overlap of symptom categories frequently occurs and has a negative impact on treatment outcomes. There is a lack of guidance on their management. An Asian Pacific Association of Gastroenterology (APAGE) working group was set up to develop clinical practice guidelines for management of patients with functional dyspepsia (FD) who have an overlap with another functional gastrointestinal disorder: FD with gastroesophageal reflux (FD-GERD), epigastric pain syndrome with irritable bowel syndrome (EPS-IBS), postprandial distress syndrome with IBS (PDS-IBS), and FD-Constipation. We identified putative pathophysiology to provide a basis for treatment recommendations. A management algorithm is presented to guide primary and secondary care clinicians.

Chinese Consensus Report on Family-Based Helicobacter pylori Infection Control and Management (2021 Edition).

OBJECTIVE: Helicobacter pylori infection is mostly a family-based infectious disease. To facilitate its prevention and management, a national consensus meeting was held to review current evidence and propose strategies for population-wide and family-based H. pylori infection control and management to reduce the related disease burden. METHODS: Fifty-seven experts from 41 major universities and institutions in 20 provinces/regions of mainland China were invited to review evidence and modify statements using Delphi process and grading of recommendations assessment, development and evaluation system. The consensus level was defined as ≥80% for agreement on the proposed statements. RESULTS: Experts discussed and modified the original 23 statements on family-based H. pylori infection transmission, control and management, and reached consensus on 16 statements. The final report consists of three parts: (1) H. pylori infection and transmission among family members, (2) prevention and management of H. pylori infection in children and elderly people within households, and (3) strategies for prevention and management of H. pylori infection for family members. In addition to the 'test-and-treat' and 'screen-and-treat' strategies, this consensus also introduced a novel third 'family-based H. pylori infection control and management' strategy to prevent its intrafamilial transmission and development of related diseases. CONCLUSION: H. pylori is transmissible from person to person, and among family members. A family-based H. pylori prevention and eradication strategy would be a suitable approach to prevent its intra-familial transmission and related diseases. The notion and practice would be beneficial not only for Chinese residents but also valuable as a reference for other highly infected areas.

Efficacy of keverprazan for duodenal ulcer: A phase II randomized, double-blind, parallel-controlled trial.

BACKGROUND AND AIM: Considering the limitation of varying acid suppression of proton pump inhibitors, this study was aimed to assess the efficacy, safety, and dose-effect relationship of keverprazan, a novel potassium-competitive acid blocker, in the treatment of duodenal ulcer (DU) compared with lansoprazole. METHODS: A randomized, double-blind, double-dummy, multicenter, low-dose, high-dose, and positive-drug parallel-controlled study was conducted to verify the non-inferiority of keverprazan (20 or 30 mg) to lansoprazole of 30 mg once daily for 4 to 6 weeks and dose-effect relationship of keverprazan in the treatment of patients with active DU confirmed by endoscopy. RESULTS: Of the 180 subjects randomized, including 55 cases in the keverprazan_20 mg group, 61 cases in the keverprazan_30 mg group, and 64 cases in the lansoprazole_30 mg group, 168 subjects (93.33%) completed the study. The proportions of healed DU subjects in the keverprazan_20 mg, keverprazan_30 mg, and lansoprazole_30 mg groups were respectively 87.27%, 90.16%, and 79.69% at week 4 (P = 0.4595) and were respectively 96.36%, 98.36%, and 92.19% at week 6 (P = 0.2577). The incidence of adverse events in the keverprazan_20 mg group was lower than that in the lansoprazole_30 mg (P = 0.0285) and keverprazan_30 mg groups (P = 0.0398). CONCLUSIONS: Keverprazan was effective and non-inferior to lansoprazole in healing DU. Based on the comparable efficacy and safety data, keverprazan of 20 mg once daily is recommended for the follow-up study of acid-related disorders. (Trial registration number: ChiCTR2100043455.).

Cost-efficient snare-assisted peroral endoscopic myotomy in comparison of conventional endoscopic knife for treatment of achalasia: results of a randomized controlled trial.

BACKGROUND: To date, the ideal endoscopic knife for peroral endoscopic myotomy (POEM) with good performance and cost-effectiveness is still under investigation. The present study was aimed to evaluate the efficacy, safety, and cost-effectiveness of snare-assisted POEM, compared with the conventional endoscopic knife approach. METHODS: From May 2017 to December 2018, patients with achalasia presenting for POEM without previous endoscopic or surgical therapy were prospectively recruited in this randomized controlled trial. Patients were randomly allocated to receive POEM using either the snare (snare group) or HookKnife (conventional group). The primary outcome was clinical success (Eckardt score ≤ 3) at 12-month follow-up, powered for noninferiority with a margin of -15%. The secondary outcomes included adverse events (AEs), procedure-related parameters, clinical outcomes, and cost-effectiveness. RESULTS: A total of 75 patients with similar baseline characteristics between the snare (N = 37) and conventional (N = 38) groups were included. Clinical success at 12-month follow-up was achieved in 94.6% of patients in the snare group and 92.1% of patients in the conventional group (difference, 2.5% [95% CI, -8.7% to 13.7%]; P < 0.001 for noninferiority). No severe AEs occurred in both groups. The use of snare is associated with comparable procedure time (40.6 minutes vs. 42.5 minutes, P = 0.337), a lower frequency of hemostatic forceps use (27.0% vs. 68.4%, P < 0.001), and lower hospital costs ($4271.1 vs. $5327.3, P < 0.001). The cost-effectiveness plane revealed that 96.9% of snare-assisted POEM procedures offered more cost-savings and health utility benefits. CONCLUSIONS: The snare-assisted POEM was noninferior to the conventional endoscopic knife approach in terms of clinical efficacy, with comparable safety outcomes and cost-effective benefits.

Development of a novel scoring system based on endoscopic appearance for management of rectal neuroendocrine tumors.

BACKGROUND: The clinical significance of the endoscopic appearance of rectal neuroendocrine tumors (NETs) is poorly understood. We aimed to develop a novel scoring system based on endoscopic appearances to predict endoscopically advanced disease in patients with rectal NETs when initially diagnosed. METHODS: Patients diagnosed with well-differentiated rectal NETs between January 2005 and December 2019 were retrospectively included. Logistic regression analyses were applied to study the relationship between endoscopic appearance and advanced disease. The whole dataset was randomly divided into training and validation sets, which were used to develop and validate a novel scoring system, respectively. RESULTS: 309 patients were included. The endoscopic appearance of rectal NETs was significantly associated with advanced disease (P < 0.001). A novel scoring system was developed based on endoscopic appearance, including tumor size, tumor shape, and mucosal surface, using the training set. The area under curve (AUC) of the scoring system to predict advanced disease was 0.953 (95 % confidence interval [CI] 0.915 - 0.991; P < 0.001) and 0.960 (95 %CI 0.905 - 1.000; P < 0.001) in the training and validation sets, respectively. Furthermore, the scoring system was significantly associated with tumor grade. Patients with high scores had significantly worse disease-free and overall survival than patients with low scores (P < 0.001). CONCLUSION: This novel scoring system based on the endoscopic appearance of the primary tumor can help to accurately identify patients with endoscopically advanced disease who are not suitable for endoscopic resection. In addition, it is of great value in monitoring tumor recurrence and overall survival in patients with rectal NETs.

Impact of COVID-19 outbreak on the care of patients with inflammatory bowel disease: A comparison before and after the outbreak in South China.

BACKGROUND AND AIMS: Epidemics pose a great challenge to health care of patients. However, the impact of unprecedented situation of COVID-19 outbreak on health care of inflammatory bowel disease (IBD) patients in real-world setting has seldom been investigated. METHODS: We performed an observational study in a tertiary referral IBD center in China. The mode of health care and medication use was compared before and after COVID-19 outbreak. Electronic questionnaire surveys were performed among gastroenterologists and IBD patients to investigate the impact of COVID-19 outbreak on their attitudes towards telemedicine. RESULTS: COVID-19 outbreak resulted in substantial decrease of patients participating in standard face-to-face visit during 1 month post-outbreak (n = 51) than pre-outbreak (n = 249), whereas the participation in telemedicine was significantly higher than comparable period in 2019 (414 vs 93). During the 1 month after COVID-19 outbreak, 39 (39/56, 69.6%) patients had their infliximab infusion postponed with the mean delay of 3 weeks. The immunomodulator use was similar between pre-outbreak and post-outbreak. Six elective surgeries were postponed for a median of 43 days. In post-outbreak period, 193 (193/297, 64.98%) of the surveyed physicians have used telemedicine with an increase of 18.9% compared with 46.13% (137/292) in the pre-outbreak period (P < 0.001); 331 (331/505, 65.54%) of the surveyed IBD patients supported that the use of telemedicine should be increased in future health care. CONCLUSION: COVID-19 outbreak resulted in a great change in health-care access among IBD patients including decrease in standard face-to-face visit and delay of biologics use. There was an increased use and need of telemedicine after COVID-19 outbreak.

Magnetisation transfer imaging adds information to conventional MRIs to differentiate inflammatory from fibrotic components of small intestinal strictures in Crohn's disease.

OBJECTIVES: Identifying inflammation- or fibrosis-predominant strictures in Crohn's disease (CD) is crucial for treatment strategies. We evaluated the additive value of magnetisation transfer (MT) to conventional MRI for differentiating CD strictures using surgical histopathology as a reference standard. METHODS: Twenty-eight consecutive CD patients who underwent MRI preoperatively were recruited. MRI parameters included T2-weighted imaging (T2WI) hyperintensity, bowel wall thickness, enhancement pattern changes over time, enhancement pattern and gain ratio in dynamic contrast-enhanced phases, and MT ratio. Correlation analysis was performed using Spearman's rank test. Receiver operating characteristic curve analysis and Cohen's κ were used. A model with combined MRI variables characterising intestinal strictures was proposed and validated in 14 additional CD patients. RESULTS: Significant correlations with histological inflammation scores were shown for wall thickness (r = 0.361, p = 0.001) and T2WI hyperintensity (r = 0.396, p < 0.001), whereas histological fibrosis scores were significantly correlated with MT ratio (r = 0.681, p < 0.001) and wall thickness (r = 0.461, p < 0.001). T2WI hyperintensity could differentiate mild from moderate-to-severe inflammation with a sensitivity of 0.871 and a specificity of 0.800. MT ratio could discriminate mild from moderate-to-severe fibrosis with a sensitivity and a specificity of 0.913 and 0.923, respectively. Combining MT ratio and T2WI hyperintensity, the MRI classification moderately agreed with the pathological stricture classification (p < 0.01, κ = 0.549). In the validation set, the diagnostic accuracy of T2WI hyperintensity and MT ratio were 86% and 89%, with good agreement between MRI and histopathological classification (p < 0.01, κ = 0.665). CONCLUSIONS: MT ratio combined with conventional MRI improves the differentiation of fibrotic from inflammatory components of small-bowel strictures in CD patients. KEY POINTS: • MT ratio from magnetisation transfer imaging combined with T2WI from conventional MRI can simultaneously characterise bowel fibrosis and inflammation in adult Crohn's disease.

Ability of DWI to characterize bowel fibrosis depends on the degree of bowel inflammation.

OBJECTIVES: Although diffusion-weighted imaging (DWI) is reported to be accurate in detecting bowel inflammation in Crohn's disease (CD), its ability to assess bowel fibrosis remains unclear. This study assessed the role of DWI in the characterization of bowel fibrosis using surgical histopathology as the reference standard. METHODS: Abdominal DWI was performed before elective surgery in 30 consecutive patients with CD. The apparent diffusion coefficients (ADCs) in pathologic bowel walls were calculated. Region-by-region correlations between DWI and the surgical specimens were performed to determine the histologic degrees of bowel fibrosis and inflammation. RESULTS: ADCs correlated negatively with bowel inflammation (r = - 0.499, p < 0.001) and fibrosis (r = - 0.464, p < 0.001) in 90 specimens; the ADCs in regions of nonfibrosis and mild fibrosis were significantly higher than those in regions of moderate-severe fibrosis (p = 0.008). However, there was a significant correlation between the ADCs and bowel fibrosis (r = - 0.641, p = 0.001) in mildly inflamed segments but not in moderately (r = - 0.274, p = 0.255) or severely (r = - 0.225, p = 0.120) inflamed segments. In the mildly inflamed segments, the ADCs had good accuracy with an area under the receiver-operating characteristic curve of 0.867 (p = 0.004) for distinguishing nonfibrosis and mild fibrosis from moderate-severe fibrosis. CONCLUSIONS: ADC can be used to assess bowel inflammation in patients with CD. However, it only enables the accurate detection of the degree of bowel fibrosis in mildly inflamed bowel walls. Therefore, caution is advised when using ADC to predict the degree of intestinal fibrosis. KEY POINTS: • Diffusion-weighted imaging was used to assess bowel inflammation in patients with Crohn's disease. • The ability of diffusion-weighted imaging to evaluate bowel fibrosis decreased with increasing bowel inflammation. • Diffusion-weighted imaging enabled accurate detection of the degree of fibrosis only in mildly inflamed bowel walls.

IVIM with fractional perfusion as a novel biomarker for detecting and grading intestinal fibrosis in Crohn's disease.

OBJECTIVES: Intravoxel incoherent motion (IVIM) diffusion-weighted magnetic resonance imaging (MRI) provides information on both perfusion and diffusion and has been used to evaluate Crohn's disease (CD) activity and fibrosis in children; however, there are no reports on its use in adults. We aimed to determine its value for detecting and grading intestinal fibrosis in adults with CD compared with contrast-enhanced imaging and traditional diffusion-weighted imaging using surgical histopathology as a reference standard. METHODS: Twenty-four adults with CD underwent preoperative IVIM, traditional diffusion-weighted, and contrast-enhanced imaging. Region-by-region correlations between MRI findings and histologic findings of the surgical specimens were performed. Imaging parameters including fractional perfusion, perfusion coefficient, and diffusion coefficient for IVIM and apparent diffusion coefficient value for traditional diffusion-weighted imaging and contrast-enhanced parameter of 95 bowel lesions were measured. Intestinal fibrosis was histologically scored from 0 to 3. RESULTS: The fractional perfusion (r = - 0.629, p < 0.001) and apparent diffusion coefficient values (r = - 0.495, p < 0.001) were significantly correlated with fibrosis scores. Fractional perfusion decreased following increases in fibrosis severity from mild, to moderate, to severe (p < 0.001). The area under the receiver operating characteristic curve for distinguishing moderate-severe from mild fibrosis was 0.876 (p < 0.001) for fractional perfusion, followed by 0.802 for apparent diffusion coefficient value (p < 0.001). Perfusion coefficient, diffusion coefficient, and contrast-enhanced parameter were uncorrelated with histological fibrosis. CONCLUSIONS: IVIM diffusion-weighted magnetic resonance imaging outperforms traditional diffusion-weighted and contrast-enhanced imaging in grading bowel fibrosis, and fractional perfusion may be a promising biomarker for fibrosis severity in adults with CD. KEY POINTS: • Intravoxel incoherent motion diffusion-weighted MRI outperforms contrast-enhanced imaging and traditional diffusion-weighted MRI for detecting and grading intestinal fibrosis in adult Crohn's disease. • The parameter fractional perfusion, a promising biomarker for fibrosis severity, may be beneficial for treatment planning and monitoring of bowel fibrosis in adult Crohn's disease. • Perfusion coefficient, diffusion coefficient, and the percentage of enhancement gain between 70 s and 7 min were uncorrelated with histological fibrosis.

Low 6-thioguanine nucleotide level: Effective in maintaining remission in Chinese patients with Crohn's disease.

BACKGROUND AND AIM: Measuring 6-thioguanine nucleotide (6-TGN) level is useful in optimizing dose of azathioprine (AZA) and monitoring for toxicity. Lower dose of AZA was suggested for maintenance of clinical remission in Asian patients than Caucasian patients with Crohn's disease (CD). However, the optimal 6-TGN threshold required in Asian patients is undetermined. Therefore, the aim of the current study is to explore the optimal 6-TGN threshold required in Asian patients with CD for maintenance of clinical remission. METHODS: A retrospective cohort study in a tertiary referral center recruited 252 CD patients. The primary endpoint was disease relapse. The levels of 6-TGN and AZA dose were compared in remission group and relapse group. Remission rate was compared across the increased 6-TGN level and dose range. RESULTS: Patients with 6-TGN range of 0-180.94 pmol/8 × 108 red blood cells (RBC) had lower remission rate compared with those with 180.94-255.50 pmol/8 × 108 RBC (P = 0.020). Quartile analysis showed that increasing 6-TGN level beyond 180 pmol/8 × 108 RBC produced negligible gain in rate of remission. Frequency of adverse events significantly increased in patients with 6-TGN level > 355 pmol/8 × 108 RBC (8.0% with 6-TGN > 355 pmol/8 × 108 RBC vs 2.7% with 6-TGN < 355 pmol/8 × 108 RBC, P = 0.035). CONCLUSION: Our study suggested that optimal 6-TGN threshold required to maintain clinical remission in Chinese patients was 180-355 pmol/8 × 108 RBC.

Best practices on immunomodulators and biologic agents for ulcerative colitis and Crohn's disease in Asia.

The Asia-Pacific Working Group on Inflammatory Bowel Disease was established in Cebu, Philippines, under the auspices of the Asia-Pacific Association of Gastroenterology with the goal of improving inflammatory bowel disease care in Asia. This consensus is carried out in collaboration with Asian Organization for Crohn's and Colitis. With biologic agents and biosimilars becoming more established, it is necessary to conduct a review on existing literature and establish a consensus on when and how to introduce biologic agents and biosimilars in conjunction with conventional treatments for ulcerative colitis and Crohn's disease in Asia. These statements also address how pharmacogenetics influences the treatments of ulcerative colitis and Crohn's disease and provides guidance on response monitoring and strategies to restore loss of response. Finally, the review includes statements on how to manage treatment alongside possible hepatitis B and tuberculosis infections, both common in Asia. These statements have been prepared and voted upon by members of inflammatory bowel disease workgroup employing the modified Delphi process. These statements do not intend to be all-encompassing, and future revisions are likely as new data continue to emerge.

Characterization of Degree of Intestinal Fibrosis in Patients with Crohn Disease by Using Magnetization Transfer MR Imaging.

Purpose To evaluate the role of magnetization transfer (MT) magnetic resonance (MR) imaging for the characterization of intestinal fibrosis compared with contrast material-enhanced and diffusion-weighted MR imaging and its capability for differentiating fibrotic from inflammatory strictures in humans with Crohn disease (CD) by using surgical histopathologic analysis as the reference standard. Materials and Methods Institutional review board approval and informed consent were obtained for this prospective study. Abdominal MT imaging, contrast-enhanced imaging, and diffusion-weighted imaging of 31 consecutive patients with CD were analyzed before elective surgery. The bowel wall MT ratio normalized to skeletal muscle, the apparent diffusion coefficient (ADC), and the percentage of enhancement gain were calculated; region-by-region correlations with the surgical specimen were performed to determine the histologic degree of fibrosis and inflammation. The performance of MT imaging was validated in five new patients. One-way analysis of variance test, Spearman rank correlation, and receiver operating characteristic curve were used for statistical analysis. Results Normalized MT ratios strongly correlated with fibrosis scores (r = 0.769; P = .000) but did not correlate with inflammation scores (r = -0.034; P = .740). Significant differences (F = 49.002; P = .000) in normalized MT ratios were found among nonfibrotic, mildly, moderately, and severely fibrotic walls. The normalized MT ratios of mixed fibrotic and inflammatory bowel walls were significantly higher than those of bowel walls with only inflammation present (t = -8.52; P = .000). A high accuracy of normalized MT ratios was shown with an area under the receiver operating characteristic curve (AUC) of 0.919 (P = .000) for differentiating moderately to severely fibrotic bowel walls from nonfibrotic and mildly fibrotic bowel walls, followed by ADC (AUC, 0.747; P = .001) and the percentage of enhancement gain (AUC, 0.592; P = .209). The sensitivity, specificity, and AUC of MT imaging for diagnosing moderate to severe fibrosis in the validation data set were 80% (12 of 15), 100% (three of three), and 0.9 (P = .033), respectively. Conclusion MT imaging outperforms ADC and contrast-enhanced imaging in detecting and distinguishing varying degrees of bowel fibrosis with or without coexisting inflammation. MT imaging could potentially be used as a method to differentiate fibrotic from inflammatory intestinal strictures in patients with CD. © RSNA, 2018 Online supplemental material is available for this article.

Prolonged azathioprine treatment reduces the need for surgery in early Crohn's disease.

BACKGROUND AND AIM: Whether an early use of azathioprine (AZA) can alter the natural history of Crohn's disease (CD) remains debated. The aim of this study is to evaluate the impact of AZA on disease progression in a cohort of patients with early CD. METHODS: This longitudinal cohort study examined patients with early CD defined as disease duration ≤ 18 months and no previous use of disease-modifying agents according to Paris definition. The primary outcome was the proportion of CD-related intestinal surgery. Cox regression analysis was performed to identify potential predictive factors of CD progression. RESULTS: One-hundred and ninety patients with early CD were enrolled in the study. After a median follow-up of 57 months (interquartile range, 31.3-76.2), 31 patients underwent abdominal surgeries, 48 patients were hospitalized, and 68 patients experienced clinical flares. The cumulative rate of remaining free of CD-related bowel surgery, hospitalization, and flare at 5 years on AZA treatment was 0.65, 0.59, and 0.39, respectively. Three independent predictors of CD-related operations were identified: prior bowel resection (hazard ratio [HR], 9.23; 95% confidence interval [CI] 3.67-23.23), smoker (HR, 4.0; 95% CI 1.38-11.65), and hemoglobin < 110 g/L at the time of initiation of AZA (HR, 4.36; 95% CI 1.80-10.58). Conversely, AZA treatment duration > 36 months (HR, 0.04; 95% CI 0.01-0.15) was associated with reduced CD-related operations. CONCLUSION: Prior bowel resection, smoking, and hemoglobin < 110 g/L at the time of initiation of AZA were risk factors associated with intestinal surgery in patients with early CD. However, prolonged use (≥ 36 months) of AZA was associated with a more favorable disease course of early CD.

Thiopurines prevented surgical recurrence in patients with Crohn's disease after intestinal resection: Strategy based on risk stratification.

BACKGROUND AND AIM: Thiopurines (TPs) are effective in reducing clinical and endoscopic recurrence in postoperative patients with Crohn's disease (CD). However, whether TPs could prevent surgical recurrence (SR) remains unknown. We aimed to explore whether TPs could prevent SR and identify risk factors associated with SR. METHODS: This was a retrospective cohort study of 246 postoperative patients with CD. Cox proportional hazard model was used to identify risk factors for SR. Patients were stratified according to the presence of risk factors. RESULTS: A total of 50 (20.3%) patients suffered SR after a mean follow up of 54.3±46.4 months. Multivariable analysis showed independent risk factors for SR were penetrating disease behavior (HR 8.628; 95% CI 1.573-47.341; P = 0.01), ileocolonic disease location (HR 2.597; 95% CI 1.047-6.445; P = 0.04) and isolated upper gastrointestinal disease (UGID) location (HR 5.082; 95% CI 1.496-17.267; P = 0.009). However, use of TPs after surgery significantly reduced the risk of SR (HR 0.120; 95% CI 0.063-0.231; P < 0.001). When stratifying patients according to risk factors, there was no statistical difference of SR between patients treated or not by TPs (P = 0.08) in low-risk group (n = 46). However, in high risk group (n = 200), patients with TPs use had a lower risk of SR than those without TPs (HR 0.093; 95% CI 0.048-0.178; P < 0.001). CONCLUSIONS: Penetrating disease behavior and ileocolonic/isolated (UGID) location were associated with SR in CD patients. TPs use was beneficial in decreasing risk for SR in CD patients at high risk.

Effects of Combination Therapy With Immunomodulators on Trough Levels and Antibodies Against Tumor Necrosis Factor Antagonists in Patients With Inflammatory Bowel Disease: A Meta-analysis.

BACKGROUND & AIMS: It is not clear whether combination therapy with immunomodulators affects the immunogenicity of tumor necrosis factor (TNF) antagonists in patients with inflammatory bowel disease. We performed a meta-analysis to quantify the effects of combined immunomodulator therapy on the presence of antibodies against TNF antagonists (antidrug antibodies [ADAs]) and trough levels of anti-TNF agents. METHODS: We systematically searched publication databases for studies that reported prevalence of ADAs in patients who received anti-TNF agents. Raw data from studies that met the inclusion criteria were pooled to determine effect estimates. We performed subgroup and metaregression analyses to determine the level of heterogeneity among study outcomes. RESULTS: We analyzed findings from 35 studies that met inclusion criteria (results reported from 6790 patients with inflammatory bowel disease). The pooled risk ratio for formation of ADAs in patients receiving combined therapy with immunomodulators, versus that of patients receiving anti-TNF monotherapy, was 0.49 (95% confidence interval, 0.41-0.59; P < .001). However, the pooled analysis did not demonstrate a significant difference in trough levels of anti-TNF agents between patients with versus without concurrent use of immunomodulators (standardized mean difference, 0.11; 95% confidence interval, 0.19-0.41; P = .47). Subgroup analyses of patients treated with different TNF antagonists revealed no difference in the formation of ADAs (P = .50 for interaction); the protective effect of immunomodulators did not differ with type of drug patients were given (methotrexate vs thiopurines), or assay for ADA. We observed heterogeneity only among studies of patients with ulcerative colitis (I2 = 76%). Funnel plot and Egger test analyses indicated publication bias in the studies (P = .001). CONCLUSIONS: In a meta-analysis of published studies, we associated combined treatment with immunomodulators with reduced risk of formation of antibodies against TNF antagonists in patients with inflammatory bowel disease.