[This retracts the article DOI: 10.1016/j.omto.2021.01.013.].

Background/Objectives There is no predictive model available to address early stage malignant intraductal papillary mucinous neoplasm (IPMN) including high grade dysplasia (HGD) and pT1a (invasive component≤0.5 cm). The aim of this study was to establish an objective and sufficient model to predict the degree of malignancy in patients with IPMN, which can be easily applied in daily practice and adopted for any type of lesion. Methods A retrospective cohort study of 309 patients who underwent surgical resection for IPMN was performed. Members of the cohort were randomly allocated to the training or testing set. A detection tree model and random forest model were used for a 3-class classification to distinguish low grade dysplasia (LGD), HGD/pT1a IPMN, and invasive intraductal papillary mucinous cancer (I-IPMC) beyond pT1a. Results Of the 309 patients, 54 (17.4%) had early stage malignancy (19 HGD, 35 pT1a), 49 (15.9%) had I-IPMC beyond pT1a, and 206 (66.7%) had LGD IPMN. We proposed a 3-class classification model using a random forest algorithm, and the model had an accuracy of 99.5% with the training set, and displayed an accuracy of 96.0% with the testing set. We used SHAP for interpretation of the model and showed the top five factors (mural nodule size, main pancreatic duct diameter, CA19-9 levels, lesion edge and common bile duct dilation) were most likely to influence the 3-class classification results in terms of interpretation of the random forest model. Conclusions This predictive model will help assess an individual’s risk for different stages of IPMN malignancy and may help identify patients with IPMN who require surgery.

Microbiota-induced tumorigenesis is well established in solid tumors of the gastrointestinal tract but rarely explored in hematologic malignancies. To determine the role of gut microbiota in lymphoma progression, we performed metagenomic sequencing on human primary gastrointestinal B cell lymphomas. We identified a distinct microbiota profile of intestinal lymphoma, with significantly decreased symbiotic microbes, particularly the genus Eubacterium and notably butyrate-producing Eubacterium rectale. Transfer of E. rectale-deficit microbiota of intestinal lymphoma patients to mice caused inflammation and tumor necrosis factor (TNF) production. Conversely, E. rectale treatment reduced TNF levels and the incidence of lymphoma in sensitized E mu-Myc mice. Moreover, lipopolysaccharide from the resident microbiota of lymphoma patients and mice synergizes with TNF signaling and reinforces the NF-kappa B pathway via the MyD88-dependent TLR4 signaling, amalgamating in enhanced intestinal B cell survival and proliferation. These findings reveal a mechanism of inflammationassociated lymphomagenesis and a potential clinical rationale for therapeutic targeting of gut microbiota.

This article has been retracted. Please see the Retraction Notice for more detail: https://doi.org/10.1186/s13046-019-1098-y.

目的:了解活动性肛瘘(active anal fistula,AAF)的缓解是否直接影响克罗恩病(Crohn's disease,CD)患者的生活质量(quality of life,QoL)、自尊和身体形象,以及英夫利昔单抗(infliximab,IFX)治疗是否可以改善其社会心理障碍.方法:回顾性收集我院炎症性肠病(inflammatory bowel disease,IBD)数据库中AAF的CD患者的基线信息、CD相关临床特征、肛瘘类型、肛周CD活动指数、IBD简化问卷、身体形象量表、罗森伯格自尊量表,以及6～12个月的治疗和随访数据.评估IFX治疗对改善心理社会状况的影响.结果:297例CD患者中103例(34.7％)存在AAF.IFX治疗AAF患者的缓解率为64.0％,显著高于未接受IFX治疗AAF患者的缓解率(38.5％,P=0.010).此外,与未接受IFX治疗的AAF患者相比,接受IFX治疗的AAF患者的QoL、身体形象满意度和自尊的改善更显著(均P<0.05).结论:肛瘘缓解可改善AAF CD患者的自卑心理、形象满意度和QoL.IFX通过显著改善CD患者的肛瘘病情,促进患者身心健康,提高患者QoL.

Background and Aims Sarcopenia is a prognostic factor of outcomes for various diseases, but reports on sarcopenia in patients with Crohn's disease (CD) are few. We aim to determine the prevalence of sarcopenia and assess the role of sarcopenia in postoperative complications in patients with CD at a tertiary referral center. Methods Patients who underwent intestinal surgery for CD from January 2013 to October 2019 were retrospectively enrolled. The L3 skeletal muscle mass index (SMI) was used to identify sarcopenia. Demographic data, preoperative laboratory data, surgical details, and hospital outcomes were recorded. The factors associated with postoperative complications were evaluated through univariate and multivariate analyses. Results One hundred and twenty-four patients were enrolled. Thirty-four of them (27.4%), including 11 males, were diagnosed with sarcopenia. Compared with patients without sarcopenia, sarcopenic patients had a significantly lower BMI (P < 0.001); lower preoperative serum albumin (P = 0.006), prealbumin (P = 0.030), and hemoglobin levels (P < 0.001); longer hospital stay (34.4 ± 26.8 days vs. 22.8 ± 15.6 days, P = 0.003); and more occurrences of complications (41.2% vs. 23.3%, P = 0.049). The overall incidence of postoperative complications was 28.2%. Infection (51.4%) and intestinal fistula (22.9%) were the most common among such complications. Through the multivariate analysis, sarcopenia was identified as an independent risk factor for major postoperative complications (odds ratio = 3.974, 95%CI = 1.171–13.489, P = 0.027). Conclusion Sarcopenia is common in patients with CD requiring bowel resection, and it significantly increases the risk of major postoperative complications.

Background: The epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor erlotinib, in combination with gemcitabine, has been shown to be a promising therapy in the treatment of pancreatic cancer. Our previous study showed that DJ-1 promotes invasion and metastasis of pancreatic cancer cells by activating SRC/ERK/uPA. The aim of this study was to evaluate whether silencing DJ-1 expression can sensitize pancreatic cancer cells to erlotinib treatment. METHODS: Knockdown of DJ-1 expression, combined with erlotinib treatment, was performed in the pancreatic cancer cell lines BxPC-3, PANC-1 and MiaPACa-2. Cell proliferation was assessed with the CCK-8 assay and BrdU incorporation, while apoptosis was measured using terminal deoxynucleotidyl ransferase (TdT)-mediated dUTP nick-end labeling. RAS activity and activation of the downstream pathways involving AKT and ERK1/2 were explored to determine the underlying mechanism. RESULTS: Knockdown of DJ-1 expression accelerated erlotinib-induced cell apoptosis, and improved the inhibitory effect of erlotinib on pancreatic cancer cell proliferation in vitro and in xenograft tumor growth in vivo . Knockdown of DJ-1 decreased K-RAS expression, membrane translocation, and activity in BxPC-3 cells. Knockdown of DJ-1 also decreased K-RAS, H-RAS, and N-RAS expression in PANC-1 and MiaPACa-2 cells. Knockdown of DJ-1 synergistically inhibited AKT and ERK1/2 phosphorylation with erlotinib in pancreatic cancer cells. CONCLUSIONS: DJ-1 may activate the RAS pathway, reinforcing erlotinib drug resistance. Blocking DJ-1 in combination with the EGFR tyrosine kinase inhibitor erlotinib may be an attractive therapeutic target in pancreatic cancer.

Background The lesion of primary gastric non-Hodgkin’s lymphoma (PGL) originates from the submucosa, so conventional gastroscopy has limited diagnostic potential. This study evaluated the diagnosis and follow-up value of endoscopic ultrasonography (EUS) in PGL. Methods Seventy-nine patients diagnosed with PGL either by EUS and biopsy pathology or by postoperative pathology were included in the study. All subjects underwent EUS with deep targeted biopsy and regular follow-up. Results We found sensitivity and specificity of EUS combined with deep targeted biopsy for PGL as 87.3% (69/79) and 80.0% (20/25) respectively, and the diagnostic accuracy as 85.6% (89/104). EUS combined with deep targeted biopsy had significantly greater diagnostic accuracy than gastroscopy [85.6% (89/104) vs. 57.7% (60/104); (P<0.001)]. The diagnostic accuracy of T tumor staging and N tumor staging of EUS were 13/13 and 11/13 respectively compared with postoperative staging. The mean time of complete remission of lymphoma after eradication treatment in the H. pylori-negative (successful eradication) group (3.2±0.7 months) was shorter than that in H. pylori-positive patients (failed eradication) group (4.5±0.8 months), there was statistically significant difference between the two groups (t=4.3, P<0.001). Conclusions This study demonstrated that EUS combined with deep targeted biopsy was associated with increased detection of Primary gastric non-Hodgkin’s lymphoma (PGL), in terms of depth and extent of the lesion to guide treatment selection and to evaluate treatment efficacy.

Background/Aims: To determine the characteristics of small bowel tumors (SBTs) in patients underwent double balloon endoscopy (DBE) and to compare the clinical value of DBE with other diagnostic tools. Materials and Methods: A retrospective study was conducted in patients underwent DBE procedures from March 2008 to April 2017.The demographic, clinical and pathological characteristics of patients with SBTs were recorded, while the diagnosis of SBTs was achieved either by DBE biopsy or surgical specimens. Results: One thousand one hundred and two patients (761 males, range 3-85 years) were enrolled in this study, with 1140 procedures completed in total. 99/1102 patients (9.0%) had SBTs, including benign polyps (20, 20.2%), gastrointestinal stromal tumors (GISTs) (24, 24.2%), lymphomas (13, 13.1%), adenocarcinoma (39, 39.4%), and neuroendocrine tumors (3, 3.0%). The most common clinical symptom for benign polyps was obscure gastrointestinal bleeding (OGIB) (75.0%). But among patients with malignant SBTs, the main indication for DBE was chronic abdominal pain (43.8%), followed by OGIB (36.3%), vomit (10.0%), abnormal images (6.3%) and diarrhea (3.8%) (P<0.001). Moreover, SBTs were primarily located in the jejunum alone (40/99, 40.4%). DBE had better sensitivity (89.2%), specificity (95.2%), positive predictive value (PPV) (90.0%), and negative predictive value (NPV) (94.8%) than other tools for suspected SBTs. Conclusion: Small bowel tumor is mainly located in jejunum and with OGIB and abdominal pain as major complaints. DBE is a reliable method for the diagnosis of SBTs compared with other diagnostic tools.

BACKGROUND Patients with Crohn's disease (CD) experience physical impairments, poor quality of life and negative body image. These factors are exacerbated in CD patients with active perianal fistulas. MATERIAL AND METHODS Baseline characteristics were compared in retrospectively enrolled CD patients with and without active perianal fistulas. The relationships between improvements in perianal fistulas and quality of life, body image, and self-esteem were determined. The effects of infliximab treatment on improvement of psychological-social status were assessed in CD patients with active perianal fistulas. RESULTS Of the 301 CD patients included in our institution's database. 91 (30.2%) had active perianal fistulas. After adjustment by propensity score matching, CD patients with active perianal fistulas had lower self-esteem and more severe body image dissatisfaction than CD patients without active perianal fistulas (P<0.01 each). Perianal fistula response was closely associated with improvements in quality of life, body image dissatisfaction and self-esteem (P<0.01 each). Patients with perianal fistula treated with infliximab showed a response rate of 68.3%, significantly higher than the rate in patients with perianal fistula not treated with infliximab (P=0.005). Furthermore, improvements of life quality, body image and self-esteem were significantly greater in patients with perianal fistula who were than were not treated with infliximab (P<0.05 each). CONCLUSIONS CD patients with active perianal fistulas experience body image dissatisfaction, low self-esteem and poor quality of life. Treatment of these patients with infliximab could improve their body image, self-esteem and quality of life.

OBJECTIVE:Medication adherence is crucial in the management of Crohn's disease (CD), and yet the adherence remains low. This study aimed to develop machine learning models that can help predict CD patients of nonadherence to azathioprine (AZA), and thus assist caregivers to streamline the intervention process.METHODS:This single-centered, cross-sectional study recruited 446 CD patients who have been prescribed AZA between Sep 2005 and Sep 2018. Questionnaires of medication adherence, anxiety and depression, beliefs of medication necessity and concerns, and medication knowledge were provided to patients, while other data were extracted from the electronic medical records. Two machine learning models of back-propagation neural network (BPNN) and support vector machine (SVM) were developed and compared with logistic regression (LR), and assessed by accuracy, recall, precision, F1 score and the area under the receiver operating characteristic curve (AUC).RESULTS:The average classification accuracy and AUC of the three models were 81.6% and 0.896 for LR, 85.9% and 0.912 for BPNN, and 87.7% and 0.930 for SVM, respectively. Multivariate analysis identified four risk factors associated with AZA nonadherence: medication concern belief (OR=3.130, p<0.001), education (OR=2.199, p<0.001), anxiety (OR=1.549, p<0.001) and depression (OR=1.190, p<0.001), while medication necessity belief (OR=0.004, p<0.001) and medication knowledge (OR=0.805, p=0.013) were protective factors.CONCLUSION:We developed three machine learning models and proposed an SVM model with promising accuracy in the prediction of AZA nonadherence in Chinese CD patients. The study also reconfirmed that education, psychologic distress, and medication beliefs and knowledge are correlated to AZA nonadherence.

Aim . To determine the risk factors of nonadherence to azathioprine (AZA) maintenance therapy for Crohn’s disease (CD) and to evaluate the influence of patients’ educational program on adherence to AZA maintenance therapy. Methods . Patients receiving AZA as maintenance therapy for CD were enrolled. Demographic data, clinical data, and usage information were collected. Univariate and multivariate analyses were performed to identify the risk factors of nonadherence. Then, patients’ educational program was conducted. One year after the program, the improvements in adherence and relapse rates were compared between educational and noneducational groups. Results . A total of 378 CD patients receiving AZA as maintenance therapy were enrolled from September 2008 to September 2018. Nonadherence occurred in 43.9% (166/378) of patients. Univariate analysis revealed that young age, education, alcoholism, anxiety, depression, concern belief, and lack of necessity belief and AZA knowledge were risk factors of nonadherence (P<0.05). Multivariate logistic regression showed that anxiety (OR 6.244, 95% CI 2.563–15.213), depression (OR 3.801, 95% CI 1.281–11.278), and concern belief (OR 19.531, 95% CI 3.393–120.732) were independent risk factors of nonadherence. Necessity belief (OR 0.961, 95% CI 0.925–0.999) and AZA knowledge (OR 0.823, 95% CI 0.758–0.903) were protective factors of adherence. One year after the AZA educational program, the necessity belief, AZA knowledge, and adherence of the educational group significantly improved (P<0.05). Concern belief was significantly lower in the educational group than that in the noneducational group (P<0.05). Moreover, the noneducational group suffered significantly higher endoscopic relapse rates than that the educational group (15.9% vs. 30.1%, P=0.035). Conclusions . Nonadherence occurred frequently in CD patients receiving AZA maintenance therapy. Educational programs could improve patients’ adherence mainly by promoting their beliefs and knowledge of AZA and could reduce relapse rates during treatment.

Background. Double-balloon enteroscopy (DBE) is widely used worldwide. However, comparisons between the diagnostic yields in adults and the elderly remain scarce. Aim. The aim of this study is to compare the diagnostic yields and safety of DBE between adults and elderly with obscure gastrointestinal bleeding and incomplete small bowel obstruction. Method. We retrospectively reviewed patients who underwent DBE with indication of obscure gastrointestinal bleeding or incomplete small bowel obstruction in Ruijin Hospital and classified them into adults (18–64 years old) and elderly (≥65 years old). Clinical characteristics, diagnostic yields, and postoperative complications were collected and further analyzed. Results. A total of 877 DBE procedures, 729 in adults and 148 in the elderly, were performed. In the patients with OGIB, the adults showed a higher frequency of Meckel’s diverticulum compared with the elderly (4.6% vs. 0.9%, P=0.032). Angioectasia was higher in frequency in the elderly than in the adults (25.9% vs. 17.9%, P=0.048). In patients with incomplete small bowel obstruction, the elderly were more likely to have adenocarcinoma than the adults (19.4% vs. 7.1%, P=0.038). The adults had higher tendency to have Crohn’s disease than the elderly (23.4% vs. 8.3%, P=0.045). Most of the postoperative complications were mild. The adults and elderly displayed comparable tolerance to DBE (P>0.05) Conclusion. DBE has a high diagnostic yield in small bowel disorders, and a slight difference in disease spectrum was observed between the adults and elderly. DBE can be well-tolerated in the elderly.

Background and aim: AZD8055, a new immunosuppressive reagent, a dual TORC1/2 inhibitor, had been used successfully in animal models for heart transplantation. The aim of this study was to evaluate the effects and mechanisms of AZD8055 on chronic intestinal inflammation. Methods: Dextran sulfate sodium (DSS) - induced chronic colitis was used to investigate the effects of AZD8055 on the development of colitis. Colitis activity was monitored by body weight assessment, colon length, histology and cytokine profile analysis. Results: AZD8055 treatment significantly alleviated the severity of colitis, as assessed by colonic length and colonic damage. In addition, AZD8055 treatment decreased the colonic CD4+ T cell numbers and reduced both Th1 and Th17 cell activation and cytokine production. The percentages of Treg cells in the colon were also expanded by AZD8055 treatment. Furthermore, AZD8055 effectively inhibited mTOR downstream proteins and signal transducer and activator of transcription related proteins in CD4+ T cells of intestinal lamina propria. Conclusions: These findings increased our understanding of DSS-induced colitis and shed new lights on mechanisms of digestive tract chronic inflammation. Dual TORC1/2 inhibition showed potent anti-inflammatory and immune regulation effects by targeting critical signaling pathways. The results supported the strategy of using dual mTOR inhibitor to treat inflammatory bowel disease.

Aim. This study aims to analyze factors possibly related to the prognosis of duodenal gastrointestinal stromal tumors (DGISTs). Methods. We collected and retrospectively analyzed clinical and pathological data of 62 patients with primary DGISTs. All the patients were hospitalized and received complete surgical resection at Shanghai Ruijin Hospital from September 2003 to April 2015. We followed up the patients to determine survival outcomes. We also analyzed the effect of clinical and pathological factors on disease-free survival (DFS) and overall survival (OS) of the patients. Results. Kaplan-Meier univariate survival analysis demonstrated that tumor size, mitotic index, Ki-67 index, and pathological risk were correlated with the DFS and OS of the patients (DFS P=0.039, 0.001, <0.001, and 0.005, resp.; OS P=0.027, 0.007, <0.001, and 0.012, resp.). Cox multivariate regression analysis revealed that Ki-67 index was an independent prognostic factor affecting DFS and OS (P=0.007 and 0.028, resp.). Moreover, Kaplan-Meier survival analysis showed that imatinib treatment for patients with recurrence was correlated with prolonged OS (P=0.002). Conclusion. Prognosis for DGIST treated by R0 resection is favorable. High level of Ki-67 can be an independent risk factor of DGIST prognosis. Adjuvant imatinib therapy for patients with tumor recurrence could probably lead to prolonged survival.

Background Patients with newly diagnosed Crohn’s disease (CD) are associated with impaired physical and psychological well-being. These psychological characteristics are dynamic with the course of disease and could be influenced by medical treatment. Infliximab is effective and widely used in moderate-to-severe CD patients. The aim of this study was to evaluate the improvement of psychological status after infliximab treatment in patients with newly diagnosed CD. Methods Newly diagnosed moderate-to-severe CD patients were prospectively enrolled in our study. Infliximab 5 mg/kg was administered at weeks 0, 2, 6, 14, 22, and 30. Outcomes including disease severity, illness perceptions, coping strategies, anxiety, depression, and quality of life (QoL) were measured at baseline, week 14, and week 30. Results Eighty-two patients completed our study. The rates of clinical remission at weeks 14 and 30 were 59/82 (72.0%) and 58/82 (70.7%), respectively. Patients who achieved clinical remission at weeks 14 and 30 significantly improved in illness perceptions (P<0.001 and <0.001), maladaptive coping (P=0.005 and 0.004), anxiety (P<0.001 and <0.001), depression (P=0.004 and 0.004), and QoL (P<0.001 and <0.001). However, emotion-focused coping and problem-focused coping remained unchanged. For infliximab nonresponders, no significant changes were seen in illness perceptions, coping strategies, anxiety, depression, or QoL at week 14 or 30. Conclusion Effective infliximab treatment not only led to clinical remission in patients with newly diagnosed moderate-to-severe CD but also improved their psychological status including illness perceptions, maladaptive coping, anxiety, depression, and QoL.

Background Computed tomography enterography (CTE) and double-balloon enteroscopy (DBE) are widely used in diagnosis of small bowel diseases. Both of these examinations bring discomfort to patients. The aim of this study was to compare patients’ tolerance and preference between CTE and DBE. Methods From August 1, 2014 to December 31, 2016, patients with suspected or known small bowel diseases who underwent both CTE and DBE were prospectively enrolled in our study. They were asked to fill out a questionnaire evaluating discomfort of the procedure after each examination. Results One hundred and seven patients completed our study. Abdominal distension, painfulness, tenesmus, general discomfort, prolonged duration, difficulty in completing the test, and discomfort after the examination were significantly lower with CTE than with DBE (P<0.001, respectively). Mannitol intake (47.7%), bowel preparation (31.9%), and radiation exposure (15.0%) were regarded as the three most intolerable burdens in CTE. Painfulness (38.3%), bowel preparation (26.2%), and invasiveness (16.8%) were considered as the three most unacceptable parts of DBE. More patients (61.7%) preferred to repeat CTE rather than DBE (P<0.001). Conclusion Compared to DBE, CTE was a more tolerable and less burdensome examination and enjoyed higher preference by most patients.

Objective Bioagents in combination with immunosuppressors have synergistic effect in the treatment of Crohn′s disease, including clinical remission and mucosal healing. Short-term combination therapy (30 weeks) in the treatment of different CD subtypes was rarely reported. This study aimed to analyze the effect on clinical remission and mucosal healing in ileal CD (L1) and colonic CD (L2). Methods L1 and L2 CD patients diagnosed in Ruijin Hospital, Shanghai Jiao Tong University School of Medicine between Jan 2014 and Jun 2016 were enrolled. They were given Infliximab (5 mg/kg) in combination with azathioprine (1 mg/kg) for 30 weeks. Evaluation and endoscopy were performed in week 38. Clinical remission was judged by CDAI<150 and endoscopic severity was performed by SES-CD (simple endoscopic score for CD). Mucosal healing was judged by disappearance of ulcers under endoscopy. The difference between the two groups was compared. Results Fourty-three patients were enrolled in the study with 19 L1 and 24 L2 cases, the male female ratio was 31∶12 and the onset age is range 15-53 years. The CDAI score were both≥150 in the two groups before diagnosis and no statistical difference was found in CDAI in the two groups. The clinical remission and mucosal healing rate after 30 weeks was 86%(37/43) and 48.8%(21/43) (P>0.05). Clinical remission rates were 89.5%(17/19) and 83.3%(20/24)in L1 and L2 subtypes respectively.The mucosal healing rate was significantly higher in L1 than in L2 CD patients (68.4% vs. 33.3%, P=0.031). Conclusion Short-term combination therapy induced high remission rate in CD patients and half of the patients achieved mucosal healing. There is difference in mucosal healing rate between subtypes of CD patients, which is low in L2 CD compared with L1 CD, indicating longer combinational treatment for CD patients with involvement of colon. Key words: Combination therapy; Ileum CD; Colonic CD; Clinical remission; Mucosal healing

Aim . To evaluate different parameters in differentiating intestinal BD from CD. Methods . The medical records of inpatients with intestinal BD and CD were retrospectively reviewed. The univariate value of different parameters was analyzed, respectively. A differentiation model was established by pooling all valuable parameters together. Diagnostic efficacy was evaluated, and a receiver operating curve (ROC) was plotted. Results . Forty-two BD patients and ninety-seven CD patients were reviewed. Demographic and clinical parameters that showed significant value included diarrhea, fever, perianal disease, oral ulcers, genital ulcers, skin lesions, and musculoskeletal lesions. Endoscopic parameters reaching clinical significance included multiple-site lesions, lesions confined to the ileocecal region, longitudinal ulcers, round or oval ulcers, punch-out ulcers, ulcers with discrete margin, ulcer size>2 cm, stricture of bowel, and anorectal involvement. Radiologic parameters aiding the differentiation included involvement segments≤3, asymmetrical pattern of involvement, intraluminal pseudopolyp formation, target sign, stricture with proximal dilation, comb sign, and fistula. The sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of the differentiation model were 90.5%, 93.8%, 92.8%, 86.4%, and 95.8%, respectively. The cutoff value was 0.5 while the area under the ROC curve was 0.981. Conclusion . The differentiation model that integrated the various parameters together may yield a high diagnostic efficacy in the differential diagnosis between intestinal BD and CD.

Objective To analyze the efficacy and tolerance of methotrexate(MTX)in remission maintenance of Crohn′s disease (CD).Methods From June 2012 to August 2015 ,49 CD patients who received MTX as mainly treatment medication to maintain remission were enrolled.The pre-medication history,efficacy,dosage and side effects of MTX were analyzed.The effects of inducing strategy on disease recurrence were analyzed.Chi-square test and t test were used for statistical analysis.Results Among the 49 patients,34 (69.4%)received steroids for remission inducing,nine (18.4%)received infliximab for remission inducing and six (12.2%)achieved remission after operation.In the 44 patients treated with azathioprine (AZA)before,the median treatment time was one month and the dosage for withdrawal of AZA was (42.0 ± 14.8)mg/d.The most common reason was leucopenia (81 .8%, 36/44).Till the time point of follow-up,46 of the 49 CD patients still took MTX orally with a median treatment time of 16 months,and the weekly dosage was (12.7 ±2.0)mg.Thirty-one cases (67.4%) achieved clinical stability,while 15 cases (32.6%)underwent clinical recurrence.The median Crohn′s disease activity index (CDAI)was 123.5 ± 66.6.The weekly dosage of clinical stability group was (12.5 ±2.1)mg,and that of clinical recurrence group was (13.0 ±1 .7 )mg,there was no statistically significant difference between the two groups (t =0.802,P =0.426 ).The recurrence rate of steroids-induced remission group was 41 .2% (14/34 ),which was higher than that of infliximab and surgery-induced remission group (1/15),and the differnce was statistically significant (χ2 =5 .177,P =0.023 ). The common side effects were gastrointestinal reaction (26.5 %, 13/49 ), impaired liver function (20.4%,10/49)and leukopenia (12.2%,6/49).Only three cases could not tolerate the side effects and underwent medication withdrawal.Conclusions As a second-line immunosuppressant for maintanence remission in CD,MTX is effective and well-tolerated in patients.So it can be an important option during the long course of CD.