Small bowel Crohn's disease(CD)is a multi-ulcerative lesion that tends to occur in the small intestine,which leads to intestinal obstruction,stricture,and bleeding easily.With the clinical application of capsule endoscopy and balloon-assisted enteroscopy,the detection rate of small bowel CD has increased significantly.However,the treatment of small bowel CD is still a difficult issue which troubles clinical practice.It is of great significance to standardize the diagnosis and treatment process,optimize the diagnosis and treatment strategy,and further improve the diagnosis and treatment efficiency.Therefore,it is necessary to formulate an expert consensus on the endoscopic diagnosis and treatment of small bowel CD.Based on the evidence-based medicine and expert experience,the consensus focus on the clinical issues including the epidemiology,endoscopic and imaging diagnosis,enteroscopy treatment,drug treatment and follow-up of small bowel CD,and formulated relevant recommendations,so as to standardize the diagnosis and treatment process of small bowel CD and improve the prognosis of patients.

Small bowel Crohn's disease(CD)is a multi-ulcerative lesion that tends to occur in the small intestine,which leads to intestinal obstruction,stricture,and bleeding easily.With the clinical application of capsule endoscopy and balloon-assisted enteroscopy,the detection rate of small bowel CD has increased significantly.However,the treatment of small bowel CD is still a difficult issue which troubles clinical practice.It is of great significance to standardize the diagnosis and treatment process,optimize the diagnosis and treatment strategy,and further improve the diagnosis and treatment efficiency.Therefore,it is necessary to formulate an expert consensus on the endoscopic diagnosis and treatment of small bowel CD.Based on the evidence-based medicine and expert experience,the consensus focus on the clinical issues including the epidemiology,endoscopic and imaging diagnosis,enteroscopy treatment,drug treatment and follow-up of small bowel CD,and formulated relevant recommendations,so as to standardize the diagnosis and treatment process of small bowel CD and improve the prognosis of patients.

The small intestine is essential for digestion, nutrient absorption, immune regulation, and microbial balance. Its epithelial lining, containing specialized cells like Paneth cells and tuft cells, is crucial for maintaining intestinal homeostasis. Paneth cells produce antimicrobial peptides and growth factors that support microbial regulation and intestinal stem cells, while tuft cells act as chemosensors, detecting environmental changes and modulating immune responses. Along with immune cells such as intraepithelial lymphocytes, innate lymphoid cells, T cells, and macrophages, they form a strong defense system that protects the epithelial barrier. Disruptions in this balance contribute to chronic inflammation, microbial dysbiosis, and compromised barrier function-key features of inflammatory bowel disease, celiac disease, and metabolic syndromes. Furthermore, dysfunctions in the small intestine and immune cells are linked to systemic diseases like obesity, diabetes, and autoimmune disorders. Recent research highlights promising therapeutic strategies, including modulation of epithelial and immune cell functions, probiotics, and gene editing to restore gut health and address systemic effects. This review emphasizes the pivotal roles of small intestinal epithelia and immune cells in maintaining intestinal homeostasis, their involvement in disease development, and emerging treatments for intestinal and systemic disorders.
Humans ; Intestinal Mucosa/cytology* ; Intestine, Small/cytology* ; Animals ; Inflammatory Bowel Diseases/immunology* ; Celiac Disease/immunology* ; Paneth Cells/immunology*

Objective:To compare the efficacy of ustekinumab (UST) and vedolizumab (VDZ) in achieving transmural healing in active Crohn′s disease (CD).Methods:From March 1, 2020 to November 30, 2024, 112 patients with active CD treated with UST or VDZ at the Department of Gastroenterology, Tenth People′s Hospital of Tongji University were retrospectively enrolled. According to the medication regimen, the 112 patients were divided into UST group (61 cases) and VDZ group (51 cases). Collected the data at baseline, such as the disease phenotype, other medication history, and clinical indicators including C-creative protein (CRP), etc. Clinical disease activity and endoscopic disease activity were assessed by Harvey-Bradshaw index (HBI) and simplified endoscopic score for Crohn′s disease (SES-CD), respectively. Transmural healing was evaluated according to the intestinal wall thickness measured by intestinal imaging examination of the affected intestinal segment. Transmural healing was defined as bowel wall thickness <0.3 cm and 110 obvious signs of inflammation, clinical remission was defined as HBI≤4, and endoscopic remission was defined as a reduction in SES-CD ≥50% or a score of ≤2. The primary endpoint was transmural healing rate within one year after treatment. The secondary endpoints were endoscopic healing rate and clinical remission rate at 13 to 24th week and 30 to 52nd week after treatment. Chi-square test or Fisher′s exact test was used to compare the efficacy of the 2 medications.Results:There was no significant difference in transmural healing rate between UST group and VDZ group within 1 year after treatment (16.4% (10/61) vs. 23.5% (12/51), χ2=0.90, P=0.344). There were no significant differences in the healing rate between UST group and VDZ group in patients with specific baseline characteristics before treatment, including CD with stenosis, with perianal disease, no history of glucocorticoid use, secondary loss of response to anti-tumor necrosis factor (TNF)-α, SES-CD 7 to 15, decreased body mass index, and increased CRP (18.2%(6/33) vs. 19.4%(7/36), 17.9%(7/39) vs. 19.4%(6/31), 17.1%(6/35) vs. 24.2%(8/33), 20.0%(8/40) vs. 3/18, 14.3%(5/35) vs. 19.2%(5/26), 15.0%(3/20) vs. 3/10, 21.4%(6/28) vs. 5/16), all P>0.05). There was no significant difference in the clinical remission rate or endoscopic remission rate between the UST group and the VDZ group from 13 to 24th week (7/14 vs. 9/18, 3/14 vs. 7/18, RR=1.000 and 0.551, 95% confidence interval: 0.497to 2.011, 0.173to 1.755, χ2=<0.01, Fisher′s exact test, both P>0.05). There was no significant difference in clinical remission rate or endoscopic remission rate between UST group and VDZ group from week 30 to week 52 after treatment (68.5% (37/54) vs. 74.4% (32/43), 27.8% (15/54) vs. 32.6% (14/43), RR=0.921 and 0.853, 95% confidence interval: 0.716 to 1.184, 0.464 to 1.568, χ2=0.41 and 0.26, both P>0.05). In UST group, the proportion of patients with normal hemoglobin after transmural healing was higher than that of patients without transmural healing (9/10 vs. 45.1% (23/51), and the difference was statistically significant ( χ2=5.08, P=0.024). However, there were no significant differences in the proportion of patients with normal body mass index, CRP, platelet count, prealbumin, albumin, interleukin-6 or TNF-α levels after treatment between those who achieved transmural healing and those who did not in either UST group or VDZ group (all P>0.05). And in VDZ group there was no significant difference in the proportion of patients with normal hemoglobin between those who achieved transmural healing and who did not (all P>0.05). Conclusion:UST and VDZ exhibit similar efficacy in transmural healing within one year of treatment in patients with active CD.

Objective:To evaluate the efficacy and safety of adalimumab (ADA) originator and biosimilars in the treatment of Crohn′s disease (CD).Methods:From January 2020 to January 2023, the clinical data of 73 patients who were diagnosed as CD and received ADA treatment at the Department of Gastroenterology, the Tenth People′s Hospital of Tongji University were retrospectively analyzed. Among them, 30 patients received ADA originator treatment (National Medicine Approval Number SJ20181019; originator group), 23 patients received biosimilar A treatment (Medicine Medicine Approval Number S20190038; biosimilar A group), and 20 patients received biosimilar B (Medicine Medicine Approval Number S20190043; biosimilar B group). At 12 and 48 weeks after treatment, the clinical data of clinical remission (Crohn′s disease activity index(CDAI) score <150), clinical response (CDAI score decreased ≥ 70 from baseline), endoscopic remission (simple endoscopic score for Crohn′s disease (SES-CD) ≤ 2 or Rutgeerts score ≤ 1), endoscopic response (SES-CD decreased > 50% from baseline), and adverse drug reaction (ADR) were collected. Chi-square test or Fisher′s exact test was used for statistical analysis.Results:After 12 weeks of ADA treatment, the overall clinical remission rate was 69.9% (51/73), which of the biosimilar A group was 69.6% (16/23), the biosimilar B group was 75.0% (15/20), and the originator group was 66.7% (20/30). The overall clinical response rate was 83.6% (61/73), which of the biosimilar A group was 82.6% (19/23), the biosimilar B group was 80.0% (16/20), and the originator group was 86.7% (26/30). The overall endoscopic remission rate was 42.5% (31/73), which of the biosimilar A group was 52.2% (12/23), the biosimilar B group was 45.0% (9/20), and the originator group was 33.3% (10/30). The overall endoscopic response rate was 63.0% (46/73), which of the biosimilar A group was 73.9% (17/23), the biosimilar B group was 70.0% (14/20), and the originator group was 50.0% (15/30). And in the above data, there were no statistically significant differences among the 3 groups (all P>0.05). After 48 weeks of treatment, the overall clinical remission rate was 54.2% (32/59), which of the biosimilar A group was 8/18, the biosimilar B group was 9/15, and the originator group was 57.7% (15/26). The overall clinical response rate was 71.2% (42/59), which of the biosimilar A group was 10/18, the biosimilar B group was 12/15, and the originator group was 76.9% (20/26). The overall endoscopic remission rate was 25.4% (15/59), which of the biosimilar A group was 5/18, the biosimilar B group was 3/15, and the originator group was 26.9% (7/26). The overall endoscopic response rate was 40.7% (24/59), which of the biosimilar A group was 7/18, the biosimilar B group was 5/15, and the originator group was 46.2% (12/26). And in the above data, there were no statistically significant differences among the 3 groups (all P>0.05). The overall incidence of ADR was 32.9% (24/73), which of the biosimilar A group was 30.4% (7/23), the biosimilar B group was 30.0% (6/20), and the originator group was 36.7% (11/30); and there was no statistically significant difference among the 3 groups ( P=0.847). Conclusion:ADA biosimilars A and B demonstrate comparable efficacy and safety to the originator medication in the treatment of CD.

Objective:To compare and analyze the clinical efficacy and safety of ferric derisomaltose injection (FDI) and iron sucrose injection (ISI) in the treatment of iron deficiency anemia (IDA) in patients with inflammatory bowel disease (IBD).Methods:From January 1, 2023 to August 31, 2024, 89 IBD patients complicated with IDA hospitalized and treated at the Department of Gastroenterology, Tenth People′s Hospital of Tongji University were enrolled and divided into the FDI group (44 cases) and ISI group (45 cases). Patients in the FDI group and ISI group were treated with FDI and ISI, respectively, and the treatment course were both 8 weeks. The iron supplementation dose, number of injections, and efficacy (response rate) were compared between the 2 groups. Hemoglobin (Hb) levels were measured before treatment and at the 2nd, 4th, and 8th week after treatment. After 8 weeks of treatment, the changes in serum iron, C-reactive protein (CRP), Crohn′s disease activity index (CDAI), modified Mayo score, inflammatory bowel disease questionnaire (IBDQ) score, and serum phosphorus levels were compared with those before treatment. Chi-square test, paired t-test, independent sample t-test, Wilcoxon signed-rank test, and Mann-Whitney U test were used for statistical analysis. Results:The difference between required and actual iron supplementation and number of injections of the FDI group were both less than those of the ISI group ((466±264) mg vs. (571±302) mg, 1.0 (1.0, 1.0) vs. 3.0 (2.0, 5.5)), and the differences were statistically significant ( t=3.69, U=104.50; both P<0.001). After 8 weeks of treatment, the efficacy and increase in serum iron of the FDI group were both higher than those of the ISI group (81.8% (36/44) vs. 60.0% (27/45), 7.35 (4.53, 12.68) μmol/L vs. 3.60 (1.10, 8.20) μmol/L), and the differences were statistically significant ( χ2=5.12, U=545.40; P=0.024, <0.001). After 2, 4, and 8 weeks of treatment, the increase in Hb from before treatment of the FDI group were higher than those of the ISI group (22.5 (8.5, 29.0) g/L vs. 7.0 (2.0, 23.5) g/L; 29.5 (22.0, 49.8) g/L vs. 14.0 (6.0, 32.0) g/L; 36.5 (25.5, 60.5) g/L vs. 21.0 (7.0, 42.0) g/L), and the differences were statistically significant ( U=590.00, 518.00, and 584.00; all P<0.001). The reductions in CDAI, modified Mayo score, and CRP, as well as the improvement in IBDQ score before and after treatment were comparable between the FDI group and the ISI group (130.7±70.3 vs. 128.8±74.6, 7.3±2.3 vs. 5.8±3.2, 26.73 (2.44, 63.44) mg/L vs. 7.41 (1.86, 47.39) mg/L, 38.5±28.4 vs. 37.0±28.1), and the differences were not statistically significant (all P>0.05). In the FDI group serum phosphorus levels after 4 and 8 weeks of treatment were both higher than that before treatment (1.27(1.13, 1.45), 1.23(1.13, 1.40) mmol/L vs. 1.21 (1.03, 1.28) mmol/L), and the differences were statistically significant ( Z=539.00 and 454.00, both P<0.001). During the treatment, mild to moderate adverse reactions occurred in 13.6% (6/44) patients of the FDI group and 11.1% (5/45) patients of the ISI group, there were no serious adverse events. Conclusion:FDI can rapidly, effectively, and safely improve IDA in IBD patients without affecting blood phosphate metabolism.

Objective:To compare the efficacy of ustekinumab (UST) and vedolizumab (VDZ) in achieving transmural healing in active Crohn′s disease (CD).Methods:From March 1, 2020 to November 30, 2024, 112 patients with active CD treated with UST or VDZ at the Department of Gastroenterology, Tenth People′s Hospital of Tongji University were retrospectively enrolled. According to the medication regimen, the 112 patients were divided into UST group (61 cases) and VDZ group (51 cases). Collected the data at baseline, such as the disease phenotype, other medication history, and clinical indicators including C-creative protein (CRP), etc. Clinical disease activity and endoscopic disease activity were assessed by Harvey-Bradshaw index (HBI) and simplified endoscopic score for Crohn′s disease (SES-CD), respectively. Transmural healing was evaluated according to the intestinal wall thickness measured by intestinal imaging examination of the affected intestinal segment. Transmural healing was defined as bowel wall thickness <0.3 cm and 110 obvious signs of inflammation, clinical remission was defined as HBI≤4, and endoscopic remission was defined as a reduction in SES-CD ≥50% or a score of ≤2. The primary endpoint was transmural healing rate within one year after treatment. The secondary endpoints were endoscopic healing rate and clinical remission rate at 13 to 24th week and 30 to 52nd week after treatment. Chi-square test or Fisher′s exact test was used to compare the efficacy of the 2 medications.Results:There was no significant difference in transmural healing rate between UST group and VDZ group within 1 year after treatment (16.4% (10/61) vs. 23.5% (12/51), χ2=0.90, P=0.344). There were no significant differences in the healing rate between UST group and VDZ group in patients with specific baseline characteristics before treatment, including CD with stenosis, with perianal disease, no history of glucocorticoid use, secondary loss of response to anti-tumor necrosis factor (TNF)-α, SES-CD 7 to 15, decreased body mass index, and increased CRP (18.2%(6/33) vs. 19.4%(7/36), 17.9%(7/39) vs. 19.4%(6/31), 17.1%(6/35) vs. 24.2%(8/33), 20.0%(8/40) vs. 3/18, 14.3%(5/35) vs. 19.2%(5/26), 15.0%(3/20) vs. 3/10, 21.4%(6/28) vs. 5/16), all P>0.05). There was no significant difference in the clinical remission rate or endoscopic remission rate between the UST group and the VDZ group from 13 to 24th week (7/14 vs. 9/18, 3/14 vs. 7/18, RR=1.000 and 0.551, 95% confidence interval: 0.497to 2.011, 0.173to 1.755, χ2=<0.01, Fisher′s exact test, both P>0.05). There was no significant difference in clinical remission rate or endoscopic remission rate between UST group and VDZ group from week 30 to week 52 after treatment (68.5% (37/54) vs. 74.4% (32/43), 27.8% (15/54) vs. 32.6% (14/43), RR=0.921 and 0.853, 95% confidence interval: 0.716 to 1.184, 0.464 to 1.568, χ2=0.41 and 0.26, both P>0.05). In UST group, the proportion of patients with normal hemoglobin after transmural healing was higher than that of patients without transmural healing (9/10 vs. 45.1% (23/51), and the difference was statistically significant ( χ2=5.08, P=0.024). However, there were no significant differences in the proportion of patients with normal body mass index, CRP, platelet count, prealbumin, albumin, interleukin-6 or TNF-α levels after treatment between those who achieved transmural healing and those who did not in either UST group or VDZ group (all P>0.05). And in VDZ group there was no significant difference in the proportion of patients with normal hemoglobin between those who achieved transmural healing and who did not (all P>0.05). Conclusion:UST and VDZ exhibit similar efficacy in transmural healing within one year of treatment in patients with active CD.

Objective:To evaluate the efficacy and safety of adalimumab (ADA) originator and biosimilars in the treatment of Crohn′s disease (CD).Methods:From January 2020 to January 2023, the clinical data of 73 patients who were diagnosed as CD and received ADA treatment at the Department of Gastroenterology, the Tenth People′s Hospital of Tongji University were retrospectively analyzed. Among them, 30 patients received ADA originator treatment (National Medicine Approval Number SJ20181019; originator group), 23 patients received biosimilar A treatment (Medicine Medicine Approval Number S20190038; biosimilar A group), and 20 patients received biosimilar B (Medicine Medicine Approval Number S20190043; biosimilar B group). At 12 and 48 weeks after treatment, the clinical data of clinical remission (Crohn′s disease activity index(CDAI) score <150), clinical response (CDAI score decreased ≥ 70 from baseline), endoscopic remission (simple endoscopic score for Crohn′s disease (SES-CD) ≤ 2 or Rutgeerts score ≤ 1), endoscopic response (SES-CD decreased > 50% from baseline), and adverse drug reaction (ADR) were collected. Chi-square test or Fisher′s exact test was used for statistical analysis.Results:After 12 weeks of ADA treatment, the overall clinical remission rate was 69.9% (51/73), which of the biosimilar A group was 69.6% (16/23), the biosimilar B group was 75.0% (15/20), and the originator group was 66.7% (20/30). The overall clinical response rate was 83.6% (61/73), which of the biosimilar A group was 82.6% (19/23), the biosimilar B group was 80.0% (16/20), and the originator group was 86.7% (26/30). The overall endoscopic remission rate was 42.5% (31/73), which of the biosimilar A group was 52.2% (12/23), the biosimilar B group was 45.0% (9/20), and the originator group was 33.3% (10/30). The overall endoscopic response rate was 63.0% (46/73), which of the biosimilar A group was 73.9% (17/23), the biosimilar B group was 70.0% (14/20), and the originator group was 50.0% (15/30). And in the above data, there were no statistically significant differences among the 3 groups (all P>0.05). After 48 weeks of treatment, the overall clinical remission rate was 54.2% (32/59), which of the biosimilar A group was 8/18, the biosimilar B group was 9/15, and the originator group was 57.7% (15/26). The overall clinical response rate was 71.2% (42/59), which of the biosimilar A group was 10/18, the biosimilar B group was 12/15, and the originator group was 76.9% (20/26). The overall endoscopic remission rate was 25.4% (15/59), which of the biosimilar A group was 5/18, the biosimilar B group was 3/15, and the originator group was 26.9% (7/26). The overall endoscopic response rate was 40.7% (24/59), which of the biosimilar A group was 7/18, the biosimilar B group was 5/15, and the originator group was 46.2% (12/26). And in the above data, there were no statistically significant differences among the 3 groups (all P>0.05). The overall incidence of ADR was 32.9% (24/73), which of the biosimilar A group was 30.4% (7/23), the biosimilar B group was 30.0% (6/20), and the originator group was 36.7% (11/30); and there was no statistically significant difference among the 3 groups ( P=0.847). Conclusion:ADA biosimilars A and B demonstrate comparable efficacy and safety to the originator medication in the treatment of CD.

Objective:To compare and analyze the clinical efficacy and safety of ferric derisomaltose injection (FDI) and iron sucrose injection (ISI) in the treatment of iron deficiency anemia (IDA) in patients with inflammatory bowel disease (IBD).Methods:From January 1, 2023 to August 31, 2024, 89 IBD patients complicated with IDA hospitalized and treated at the Department of Gastroenterology, Tenth People′s Hospital of Tongji University were enrolled and divided into the FDI group (44 cases) and ISI group (45 cases). Patients in the FDI group and ISI group were treated with FDI and ISI, respectively, and the treatment course were both 8 weeks. The iron supplementation dose, number of injections, and efficacy (response rate) were compared between the 2 groups. Hemoglobin (Hb) levels were measured before treatment and at the 2nd, 4th, and 8th week after treatment. After 8 weeks of treatment, the changes in serum iron, C-reactive protein (CRP), Crohn′s disease activity index (CDAI), modified Mayo score, inflammatory bowel disease questionnaire (IBDQ) score, and serum phosphorus levels were compared with those before treatment. Chi-square test, paired t-test, independent sample t-test, Wilcoxon signed-rank test, and Mann-Whitney U test were used for statistical analysis. Results:The difference between required and actual iron supplementation and number of injections of the FDI group were both less than those of the ISI group ((466±264) mg vs. (571±302) mg, 1.0 (1.0, 1.0) vs. 3.0 (2.0, 5.5)), and the differences were statistically significant ( t=3.69, U=104.50; both P<0.001). After 8 weeks of treatment, the efficacy and increase in serum iron of the FDI group were both higher than those of the ISI group (81.8% (36/44) vs. 60.0% (27/45), 7.35 (4.53, 12.68) μmol/L vs. 3.60 (1.10, 8.20) μmol/L), and the differences were statistically significant ( χ2=5.12, U=545.40; P=0.024, <0.001). After 2, 4, and 8 weeks of treatment, the increase in Hb from before treatment of the FDI group were higher than those of the ISI group (22.5 (8.5, 29.0) g/L vs. 7.0 (2.0, 23.5) g/L; 29.5 (22.0, 49.8) g/L vs. 14.0 (6.0, 32.0) g/L; 36.5 (25.5, 60.5) g/L vs. 21.0 (7.0, 42.0) g/L), and the differences were statistically significant ( U=590.00, 518.00, and 584.00; all P<0.001). The reductions in CDAI, modified Mayo score, and CRP, as well as the improvement in IBDQ score before and after treatment were comparable between the FDI group and the ISI group (130.7±70.3 vs. 128.8±74.6, 7.3±2.3 vs. 5.8±3.2, 26.73 (2.44, 63.44) mg/L vs. 7.41 (1.86, 47.39) mg/L, 38.5±28.4 vs. 37.0±28.1), and the differences were not statistically significant (all P>0.05). In the FDI group serum phosphorus levels after 4 and 8 weeks of treatment were both higher than that before treatment (1.27(1.13, 1.45), 1.23(1.13, 1.40) mmol/L vs. 1.21 (1.03, 1.28) mmol/L), and the differences were statistically significant ( Z=539.00 and 454.00, both P<0.001). During the treatment, mild to moderate adverse reactions occurred in 13.6% (6/44) patients of the FDI group and 11.1% (5/45) patients of the ISI group, there were no serious adverse events. Conclusion:FDI can rapidly, effectively, and safely improve IDA in IBD patients without affecting blood phosphate metabolism.