Serum Leucine-Rich α2 Glycoprotein: A Novel Biomarker for Transmural Inflammation in Crohn's Disease.

INTRODUCTION: Leucine-rich alpha-2 glycoprotein (LRG) is a newly studied biomarker for inflammatory diseases. This study aimed to investigate whether LRG can be used for evaluating transmural activity in patients with Crohn's disease (CD). METHODS: We performed magnetic resonance enterography (MRE) in 227 consecutive patients with CD from June 2020 to August 2021. We prospectively compared MRE findings with clinical and laboratory data including LRG. MRE was evaluated using 2 validated scoring systems, and transmural inflammation was defined as having a maximum simplified magnetic resonance index of activity (sMaRIA) score of ≥4 and a 5-point classification score of ≥9, respectively. RESULTS: The correlation between LRG and the total MRE score showed a positive correlation ( r = 0.576 for the sMaRIA score, P < 0.01, and r = 0.633 for the 5-point score, P < 0.01). Serum concentrations of LRG significantly increased as MRE scores increased ( P < 0.01). The area under the curve of LRG for a sMaRIA score of ≥4 and a 5-point score of ≥9 was 0.845 and 0.869, respectively, which was significantly higher than that of CDAI ( P < 0.01) or C-reactive protein ( P < 0.01). LRG levels of ≥14 µg/mL had a 67% sensitivity and 90% specificity for a sMaRIA score of ≥4 and a 73% sensitivity and 89% specificity for a 5-point score of ≥9. Patients with high LRG levels were also strongly associated with CD-related hospitalization, surgery, and clinical relapse compared with those with low LRG levels ( P < 0.01 for all). DISCUSSION: LRG is a highly accurate serum biomarker for detecting transmural activity in patients with CD. Results need to be validated in further multicenter studies.

Serum Leucine-Rich α2 Glycoprotein: A Novel Biomarker For Small Bowel Mucosal Activity in Crohn's Disease.

Active lesions in the small bowel (SB) have been independently associated with poorer prognoses in patients with Crohn's disease (CD)1; however, there has been a lack of accurate and convenient screening methods. Past studies have found that serum levels of the glycoprotein leucine-rich α2 glycoprotein (LRG) correlates with endoscopic activity in ulcerative colitis,2,3 and this is now available for routine clinical use as a biomarker in patients with inflammatory bowel disease in Japan. LRG has not yet been thoroughly verified in CD, and we investigated whether it can be used as a serum biomarker for detecting SB mucosal activity in patients with CD.

Mucosal healing of small intestinal stricture is associated with improved prognosis post-dilation in Crohn's disease.

BACKGROUND: Small intestinal stricture is a major cause for surgery in Crohn's disease (CD). Endoscopic balloon dilation (EBD) is performed for small intestinal strictures to avoid surgery, often repeatedly. However, factors that are associated with prognosis after EBD of small intestinal strictures remain poorly investigated. Mucosal healing is the therapeutic target in CD. We aimed to investigate the impact of mucosal healing defined by the presence of ulcers at the small intestinal stricture site on the prognosis of EBD in CD patients. METHODS: We retrospectively included patients with CD who underwent initial EBD for endoscopically impassable small intestinal strictures from January 2012 to March 2020 at a single center. The association between presence of ulcer at the stricture site and surgery after EBD was examined by Cox proportional hazards model. RESULTS: Of the 98 patients included, 63 (64.3%) had ulcer at the stricture site. 20 (31.7%) of these patients underwent surgery for the stricture in due course, whereas 4 (11.4%) of the patients without ulcer of the stricture underwent surgery. In multivariate analysis, patients with ulcer of the stricture had a significantly higher risk for surgery than those without ulcer (hazard ratio 4.84; 95% confidence interval 1.58-14.79). CONCLUSION: Mucosal healing at the stricture site indicated a favorable prognosis after EBD for small intestinal strictures in CD.

Intestinal phenotype is maintained by Atoh1 in the cancer region of intraductal papillary mucinous neoplasm.

Intraductal papillary mucinous neoplasm (IPMN) is a precancerous lesion of pancreatic cancer. Although there are 4 types of IPMN, among which intestinal-type IPMN is likely to progress into invasive cancer known as colloid carcinoma, no information regarding the involvement of the intestinal phenotype in the carcinogenesis of IPMN exists. The present study was conducted to explore how the intestinal differentiation system is maintained during the tumor progression of intestinal-type IPMN using surgical resection specimens. Results showed that Atoh1, a critical transcriptional factor for intestinal differentiation toward the secretory lineages of intestinal epithelial cells, was expressed in an invasive-grade IPMN. To determine the function of Atoh1 in pancreatic cancer, we generated a pancreatic ductal adenocarcinoma (PDAC) cell line overexpressing Atoh1. In a xenograft model, we successfully induced an IPMN phenotype in PDAC cells via Atoh1 induction. Finally, for the first time, we discovered that GPA33 is expressed in intestinal-type IPMN, thereby suggesting a novel target for cancer therapy. In conclusion, the intestinal differentiation system might be maintained during tumor progression of intestinal-type IPMN. Further analysis of the function of Atoh1 in IPMN might be useful for understanding the molecular mechanism underlying the malignant potential during the tumor progression of IPMN.

Intravenous tacrolimus is a superior induction therapy for acute severe ulcerative colitis compared to oral tacrolimus.

BACKGROUND: Intravenous corticosteroid is the mainstay for managing acute severe ulcerative colitis, but one-third of patients do not respond to intravenous corticosteroid. Tacrolimus, a salvage therapy before colectomy, is usually orally administered, though its bioavailability is low compared intravenous administration. The efficacy of intravenous tacrolimus has not been widely studied. AIM: To determine the efficacy and safety of intravenous tacrolimus for the treatment of acute severe ulcerative colitis. METHODS: Eighty-seven hospitalized acute severe ulcerative colitis patients were enrolled for a prospective cohort study between 2009 and 2017. Sixty-five patients received intravenous tacrolimus and 22 received oral tacrolimus. The primary outcome was the achievement of clinical remission within 2 weeks. Relapse and colectomy incidence and adverse events were assessed at 24 weeks. RESULTS: Response rates of both treatments exceeded 50% but were not significantly different. The remission rate was higher in intravenous tacrolimus compared with oral tacrolimus. At 24 weeks, oral and intravenous tacrolimus showed similar relapse-free survival rates; however, colectomy-free survival rates were higher in intravenous tacrolimus compared with oral tacrolimus. CONCLUSIONS: Patients receiving intravenous tacrolimus achieved superior remission and colectomy-free survival rates compared with patients receiving oral tacrolimus. Safety was similar between the two treatments.

Small Bowel Healing Detected by Endoscopy in Patients With Crohn's Disease After Treatment With Antibodies Against Tumor Necrosis Factor.

BACKGROUND & AIMS: It is important to objectively assess Crohn's disease (CD) activity in patients treated with antibodies against tumor necrosis factor (anti-TNF). Detection of healing by endoscopy (endoscopic healing) associates with patient outcome, based on evidence from studies of ileocolonoscopy. We assessed endoscopic healing after treatment, based on findings from balloon-assisted enteroscopy (BAE), in patients with CD. METHODS: We performed a post-hoc analysis of data from a clinical trial from 116 patients with CD (46 with ileal and 70 with ileocolonic type) who received induction and then maintenance therapy with anti-TNF agents from January 2013 through March 2018 at a single center in Japan. We compared findings from BAE before induction therapy and then again during maintenance therapy (median 13 months later). Endoscopic healing was defined as the modified simple endoscopic score for CD below 5. We also collected data on previous treatments, makers of inflammation, and disease type. RESULTS: Before treatment, small bowel ulcerations were present in 114 patients (98%); 42 patients (60%) with ileocolonic disease had colon ulcerations. During maintenance therapy, 41/114 patients (36%) had small bowel endoscopic healing; all the patients with small bowel endoscopic healing also had colonic endoscopic healing. Colonic endoscopic healing was observed in 33/42 patients (79%). The proportion of patients with small bowel endoscopic healing was significantly lower than that of colonic endoscopic healing (P < .001). Among all patients, failure to achieve small bowel endoscopic healing was significantly associated with structuring or penetrating disease (P = .014), lack of concomitant treatment with immunomodulators (P = .015), and having received previous treatment with an anti-TNF agents (P = .018). CONCLUSIONS: In a post-hoc analysis of patients with CD treated with anti-TNF agents, we found small bowel ulcerations, detected by BAE, to be more difficult to heal than colon ulcerations.

Caudal type homeobox 2 expression induced by leukocytapheresis might be associated with mucosal healing in ulcerative colitis.

BACKGROUND AND AIM: Ulcerative colitis (UC) is a chronic inflammatory disease of the colon with an intractable, recurrent course. Although the goal of UC therapy has recently been to target mucosal healing, the molecular mechanism of mucosal healing remains unknown. In this study, we aimed to elucidate the molecular dynamics related to the proliferation and differentiation of intestinal epithelial cells during cytapheresis therapy in a short duration. METHODS: Endoscopy was performed in 26 patients with UC in multicentre hospitals, and biopsy specimens were collected from the rectum before and within two weeks after leukocytapheresis (LCAP). The expression of representative proteins in intestinal epithelial cells and pathological findings was compared before and after LCAP. RESULTS: The expression of caudal type homeobox 2 (CDX2) and a hes family bHLH transcription factor 1(HES1) markedly increased after LCAP. Patients with endoscopic improvement after LCAP showed the expression of CDX2 before LCAP. Moreover, the number of goblet cells significantly increased after LCAP. Patients without endoscopic improvement after LCAP did not show the expression of CDX2 before LCAP. However, the expression of CDX2 markedly increased after LCAP. CONCLUSION: This study suggests that cytapheresis might induce CDX2 expression without affecting the cell proliferation, thus resulting in mucosal healing with goblet cell restoration.

Atonal homolog 1 protein stabilized by tumor necrosis factor α induces high malignant potential in colon cancer cell line.

Patients with inflammatory bowel disease (IBD) have an increased risk of developing colitis-associated colorectal cancer (CAC). CAC cells often develop chemoresistance, resulting in a poorer prognosis than that of sporadic colorectal cancer (CRC). The mechanism by which CAC enhances malignant potential remains unknown. We have previously reported that the proteasomal degradation of the transcription factor Atonal homolog 1 (Atoh1) protein results in the non-mucinous form of CRC. It also remains unknown whether Atoh1 protein is expressed in CAC. Therefore, in the present study, we investigated whether Atoh1 protein stabilizes in CAC. Consequently, the treatment with TNF-α stabilized Atoh1 protein through the inactivation of GSK-3ß via Akt, resulting in the mucinous form of CRC cell lines. Atoh1 protein also enriched cancer stem cells with upregulated Lgr5 expression and cells in G0/G1 cell cycle phase, resulting in both the chemoresistance to 5-fluorouracil and oxaliplatin and the promotion of cell migration. Immunofluorescence of the human mucinous CAC specimens showed the accumulation of NF-κB p65 at nuclei with the expression of Atoh1 in mucinous cancer. In conclusion, the inflammation associated with carcinogenesis may preserve the differentiation system of intestinal epithelial cell (IEC), resulting in the acquisition of both the mucinous phenotype and high malignant potential associated with the enrichment of cancer stem cell.

Hes1 promotes the IL-22-mediated antimicrobial response by enhancing STAT3-dependent transcription in human intestinal epithelial cells.

Notch signaling plays an essential role in the proliferation and differentiation of intestinal epithelial cells (IECs). We have previously shown that Notch signaling is up-regulated in the inflamed mucosa of ulcerative colitis (UC) and thereby plays an indispensable role in tissue regeneration. Here we show that in addition to Notch signaling, STAT3 signaling is highly activated in the inflamed mucosa of UC. Forced expression of the Notch target gene Hes1 dramatically enhanced the IL-22-mediated STAT3-dependent transcription in human IECs. This enhancement of STAT3-dependent transcription was achieved by the extended phosphorylation of STAT3 by Hes1. Microarray analysis revealed that Hes1-mediated enhancement of IL-22-STAT3 signaling significantly increased the induction of genes encoding antimicrobial peptides, such as REG1A, REG3A and REG3G, in human IECs. Conversely, the reduction of Hes1 protein levels with a γ-secretase inhibitor significantly down-regulated the induction of those genes in IECs, resulting in a markedly poor response to IL-22. Our present findings identify a new role for the molecular function of Hes1 in which the protein can interact with cytokine signals and regulate the immune response of IECs.

Fluorescent labelling of intestinal epithelial cells reveals independent long-lived intestinal stem cells in a crypt.

BACKGROUND AND AIMS: The dynamics of intestinal stem cells are crucial for regulation of intestinal function and maintenance. Although crypt stem cells have been identified in the intestine by genetic marking methods, identification of plural crypt stem cells has not yet been achieved as they are visualised in the same colour. METHODS: Intestinal organoids were transferred into Matrigel® mixed with lentivirus encoding mCherry. The dynamics of mCherry-positive cells was analysed using time-lapse imaging, and the localisation of mCherry-positive cells was analysed using 3D immunofluorescence. RESULTS: We established an original method for the introduction of a transgene into an organoid generated from mouse small intestine that resulted in continuous fluorescence of the mCherry protein in a portion of organoid cells. Three-dimensional analysis using confocal microscopy showed a single mCherry-positive cell in an organoid crypt that had been cultured for >1year, which suggested the presence of long-lived mCherry-positive and -negative stem cells in the same crypt. Moreover, a single mCherry-positive stem cell in a crypt gave rise to both crypt base columnar cells and transit amplifying cells. Each mCherry-positive and -negative cell contributed to the generation of organoids. CONCLUSIONS: The use of our original lentiviral transgene system to mark individual organoid crypt stem cells showed that long-lived plural crypt stem cells might independently serve as intestinal epithelial cells, resulting in the formation of a completely functional villus.

Combination of leucine-rich alpha-2 glycoprotein and fecal markers detect Crohn's disease activity confirmed by balloon-assisted enteroscopy.

BACKGROUND/AIMS: Endoscopic activity confirmed by enteroscopy is associated with poor clinical outcome in Crohn's disease (CD). We investigated which of the existing biomarkers best reflects endoscopic activity in CD patients including the small bowel, and whether their combined use can improve accuracy. METHODS: One hundred and four consecutive patients with ileal and ileocolonic type CD who underwent balloon-assisted enteroscopy (BAE) from October 2021 to August 2022 were enrolled, with clinical and laboratory data prospectively collected and analyzed. RESULTS: Hemoglobin, platelet count, C-reactive protein, leucine-rich alpha-2 glycoprotein (LRG), fecal calprotectin, and fecal hemoglobin all showed significant difference in those with ulcers found on BAE. LRG and fecal calprotectin showed the highest areas under the curve (0.841 and 0.853) for detecting ulcers. LRG showed a sensitivity of 78% and specificity of 80% at a cutoff value of 13 µg/mL, whereas fecal calprotectin showed a sensitivity of 91% and specificity of 67% at a cutoff value of 151 µg/g. Dual positivity for LRG and fecal calprotectin, as well as LRG and fecal hemoglobin, both predicted ulcers with an improved specificity of 92% and 100%. A positive LRG or fecal calprotectin/hemoglobin showed an improved sensitivity of 96% and 91%. Positivity for LRG and either of the fecal biomarkers was associated with increased risk of hospitalization, surgery, and relapse. CONCLUSIONS: The biomarkers LRG, fecal calprotectin, and fecal hemoglobin can serve as noninvasive and accurate tools for assessing activity in CD patients confirmed by BAE, especially when used in combination.

Long-term efficacy and safety of tofacitinib in patients with ulcerative colitis: 3-year results from a real-world study.

Background/Aims: The efficacy and safety of tofacitinib for the treatment of refractory ulcerative colitis (UC) has been demonstrated in clinical trials. Although, a series of reports with real-world evidence of its short-term efficacy and safety profiles have already been published, reports of long-term real-world data have been limited. We aimed to show our 3-year evidence on the clinical use of tofacitinib for the treatment of UC, focusing on its efficacy and safety profiles. Methods: A retrospective observational study was conducted on patients who started tofacitinib for active refractory UC at our hospital. The primary outcome was the retention rate until 156 weeks after initiating tofacitinib. The secondary outcomes were short-term efficacy at 4, 8, and 12 weeks; long-term efficacy at 52, 104, and 156 weeks; prognostic factors related to the cumulative retention rate; loss of response; and safety profile, including adverse events. Results: Forty-six patients who were able to be monitored for up to 156 weeks after tofacitinib initiation, were enrolled in this study. Continuation of tofacitinib was possible until 156 weeks in 54.3%, with > 50% response rates and > 40% remission rates. Among patients in whom response or remission was achieved and tofacitinib was deescalated after 8 weeks of induction treatment, 54.3% experienced relapse but were successfully rescued by and retained on reinduction treatment, except for 1 patient. No serious AEs were observed in the study. Conclusions: Tofacitinib is effective and safe as long-term treatment in a refractory cohort of UC patients in real-world clinical practice.

A Continuous Registry of Medical Record, Patient Input, and Epidemiological Data of Patients With Ulcerative Colitis: a Multicentre, Prospective, Observational Clinical Registry Study in Japan.

BACKGROUND: This registry aims to allow for a prospective non-interventional observational study of ulcerative colitis. This will facilitate monitoring of the current state of ulcerative colitis in Japan and improving the long-term disease course and adverse events associated with current treatment options. METHODS: Inclusion of patients from five centres in Japan is planned. The study is expected to take place from July 15, 2020, to November 30, 2024. Background, demographics, and medical history/information will be collected from electronic medical records at enrolment. Medical information including medications, laboratory data, and disease activity will be collected automatically from electronic medical records throughout the study. Patient-reported quality of life data will be collected directly from patients via smartphone. Efficacy endpoints (clinical remission rate, clinical improvement rate, and endoscopic healing rate) and safety endpoints (incidence of adverse events and specific ulcerative colitis-related events) will be collected according to treatment administered. Treatment categories include no treatment, 5-aminosalicylic acids, corticosteroids, immunomodulators, immunosuppressants, anti-tumour necrosis alpha agents, cytapheresis, Janus kinase inhibitors, anti-integrin antibodies, and anti-interleukin-12/23 antibodies. CONCLUSIONS: The dataset will include cross-sectional and longitudinal data and is expected to capture the state of ulcerative colitis in Japan. Patients will be included on a large scale, and the registry will be established automatically from electronic medical records and direct patient input, facilitating the accurate recording of medical information for patients with ulcerative colitis in Japan and minimizing limitations intrinsic to databases that require manual data entry, such as the burden on participating investigators and entry of data with errors/typos.

Early resolution of bowel urgency by budesonide foam enema results in improved quality of life in patients with ulcerative colitis: a multicenter prospective observational study.

Background/Aims: Bowel urgency is an important symptom for quality of life determination in patients with ulcerative colitis (UC). Few clinical studies have focused on bowel urgency as an efficacy endpoint. Budesonide foam enema has shown efficacy for clinical and endoscopic improvement in mild-to-moderate UC. We evaluated the improvement of clinical symptoms (bowel urgency), safety, and treatment impact of twice-daily budesonide foam enema on the quality of life in patients with UC. Methods: This open-label, multicenter, prospective observational study comprised a 4-week observation period assessing the effectiveness and safety of twice-daily budesonide foam enema. Mild-to-moderate UC patients who had bowel urgency were included. Patients collected data daily in an electronic patient-reported outcome system or logbooks. The primary endpoint was the rate of resolution of bowel urgency at the end of the 4-week observation period. The rate of bowel incontinence was also assessed. Results: Sixty-one patients were enrolled. Of patients with a final evaluation, the rate of resolution of bowel urgency was 58.5% (31/53; 95% confidence interval, 44.1%-71.9%). Bowel urgency decreased over time, with a significant difference observed on day 7 versus day 0. Bowel incontinence showed a decreasing trend from day 5, with a significant difference confirmed on day 12 versus day 0. The clinical remission rate was 64.4% (38/59; 95% confidence interval, 50.9%-76.4%). One adverse event not related to budesonide rectal foam occurred. Conclusions: The findings suggest that bowel urgency can be improved early with twice-daily budesonide foam enema. No new safety signals were observed.

The acquisition of malignant potential in colon cancer is regulated by the stabilization of Atonal homolog 1 protein.

The transcription factor Atonal homolog 1 (Atoh1) plays crucial roles in the differentiation of intestinal epithelium cells. Although we have reported that the Atoh1 protein was degraded in colon cancer by aberrant Wnt signaling, a recent study has indicated that the Atoh1 protein is expressed in mucinous colon cancer (MC) and signet ring cell carcinoma (SRCC). However, the roles of the Atoh1 protein in MC are unknown. To mimic MC, a mutated Atoh1 protein was stably expressed in undifferentiated colon cancer cells. Microarray analysis revealed the acquisition of not only the differentiated cell form, but also malignant potential by Atoh1 protein stabilization. In particular, Atoh1 enhanced Wnt signaling, resulting in the induction of Lgr5 as a representative stem cell marker with the enrichment of cancer stem cells. Moreover, the fluorescent ubiquitination-based cell cycle indicator system with time-lapse live imaging demonstrated cell cycle arrest in the G0/G1 phase by Atoh1 protein stabilization. In conclusion, the Atoh1 protein regulates malignant potential rather than the differentiation phenotype of MC, suggesting the mechanism by which MC and SRCC are more malignant than non-mucinous adenocarcinoma.

Transmural Remission Characterized by High Biologic Concentrations Demonstrates Better Prognosis in Crohn's Disease.

BACKGROUND: The importance and pathophysiology of transmural healing in patients with Crohn's disease [CD] remains to be verified. We aimed to examine the association between serum concentrations of biologics and transmural remission evaluated via magnetic resonance enterography [MRE]. METHODS: We enrolled patients with CD who received maintenance biologics 1 year after induction and prospectively followed up for at least 1 year after baseline laboratory, endoscopic and MRE examination. We evaluated the relationship between baseline factors including the presence of transmural remission and patient prognosis, as well as between serum concentrations and transmural remission. RESULTS: We included 134 patients, of whom 65, 31, 27 and 11 received infliximab, adalimumab, ustekinumab and vedolizumab, respectively. Those who achieved transmural remission showed a lower risk of hospitalization and surgery than those who did not achieve remission [p < 0.01]. Adjusted hazard ratios of transmural remission for predicting hospitalization and surgery were 0.11 and 0.02, respectively, which were lower than those of clinical remission, biochemical remission and endoscopic remission. Regarding serum concentrations, the median concentration was higher in patients with transmural remission than in patients with transmural activity for all agents [p < 0.01 for infliximab, p = 0.04 for adalimumab, p < 0.01 for ustekinumab, p = 0.08 for vedolizumab]. CONCLUSIONS: Transmural remission was the best predictor for prognosis in CD patients who received maintenance biologic therapy. High drug concentration levels were associated with transmural remission confirmed via MRE.

A case of venous stasis colitis possibly caused by eplerenone.

A 50-year-old man was referred to our hospital for colitis with abdominal pain and diarrhea that had persisted for more than 8 months. 9 months earlier, he had been treated for fulminant eosinophilic myocarditis. During steroid therapy, ulceration appeared in the esophagus, stomach and large intestine. The biopsy results showed cytomegalovirus (CMV) inclusion bodies, and the patient was diagnosed with CMV gastrocolitis and treated with ganciclovir. Colonoscopy 7 months earlier revealed ischemia-like segmental colitis 10 cm in length in the hepatic flexure without evidence of CMV infection. Colonoscopy after 1 month and 3 months showed no improvement. We suspected drug-induced focal ischemic colitis, and discontinued eplerenone. Colonoscopy 2 months after withdrawal of eplerenone showed improvement in colitis, and colonoscopy 8 months later showed ulcer healing. Venous disorders are cautioned as a known side effect of eplerenone, but this is the first report of venous stasis colitis thought to be caused by eplerenone.

Hemorrhagic gastric ulcer in a patient with Behcet's disease successfully treated with infliximab.

Behcet's disease (BD) is a multisystem immune-mediated inflammatory disorder that occasionally involves the gastrointestinal tract. Reports on gastrointestinal involvement of BD are relatively rare, of which gastroduodenal involvement is particularly rare. Endoscopic features of gastroduodenal lesions are unknown, and treatment strategies have not been established. In this report, we present the case of a 72-year-old female with gastrointestinal BD who presented with extensive gastroduodenal ulcers and hematemesis that were resistant to colchicine and corticosteroid treatment, which were subsequently successfully treated with infliximab. We also review the current literature on the gastroduodenal involvement of BD. Although rare, the case highlights the importance of being aware of upper gastrointestinal manifestations of BD, as well as demonstrating the potential of infliximab to treat corticosteroid-resistant cases.

COVID-19 severity is associated with the risk of gastrointestinal bleeding.

OBJECTIVE: The association between the severity of COVID-19 and gastrointestinal (GI) bleeding is unknown. This study aimed to determine whether the severity of COVID-19 is a risk factor for GI bleeding. DESIGN: A multicentre, retrospective cohort study was conducted on hospitalised patients with COVID-19 between January 2020 and December 2021. The severity of COVID-19 was classified according to the National Institute of Health severity classification. The primary outcome was the occurrence of GI bleeding during hospitalisation. The main analysis compared the relationship between the severity of COVID-19 and the occurrence of GI bleeding. Multivariable logistic regression analysis was performed to evaluate the association between the severity of COVID-19 and the occurrence of GI bleeding. RESULTS: 12 044 patients were included. 4165 (34.6%) and 1257 (10.4%) patients had severe and critical COVID-19, respectively, and 55 (0.5%) experienced GI bleeding. Multivariable analysis showed that patients with severe COVID-19 had a significantly higher risk of GI bleeding than patients with non-severe COVID-19 (OR: 3.013, 95% CI: 1.222 to 7.427). Patients with critical COVID-19 also had a significantly higher risk of GI bleeding (OR: 15.632, 95% CI: 6.581 to 37.130). Patients with severe COVID-19 had a significantly increased risk of lower GI bleeding (OR: 10.349, 95% CI: 1.253 to 85.463), but the risk of upper GI bleeding was unchanged (OR: 1.875, 95% CI: 0.658 to 5.342). CONCLUSION: The severity of COVID-19 is associated with GI bleeding, and especially lower GI bleeding was associated with the severity of COVID-19. Patients with severe or critical COVID-19 should be treated with caution as they are at higher risk for GI bleeding.

Importance of Telomere Shortening in the Pathogenesis of Ulcerative Colitis: A New Treatment From the Aspect of Telomeres in Intestinal Epithelial Cells.

BACKGROUND AND AIMS: Ulcerative colitis [UC] is a chronic inflammatory disease of the colon with frequent relapses. Telomere shortening in intestinal epithelial cells has been reported in severe or longstanding cases. However, its influence on UC pathogenesis remains unelucidated. To this end, we evaluated telomere shortening using a long-term organoid inflammation model that we had originally established. METHODS: A UC model using human colon organoids was established to assess telomere changes chronologically. MST-312 was used for the telomerase inhibition assay. The potential of telomerase activators as a novel UC treatment was evaluated with an in vitro model, including microarray analysis, and histological changes were assessed using xenotransplantation into mouse colonic mucosa. RESULTS: Our UC model reproduced telomere shortening in vitro, which was induced by the continuous suppression of telomerase activity via P53. MST-312-based analysis revealed that telomere shortening was involved in the pathogenesis of UC. Madecassoside [MD] improved the telomere length of the UC model and UC patient-derived organoids, which further promoted cell proliferation in vitro and improved the graft take-rate of xenotransplantation. Moreover, histological analysis revealed that MD induced normal crypt structure with abundant goblet cells. CONCLUSIONS: This study is the first to reveal the mechanism and importance of telomere shortening in the pathogenesis of UC. MD could be a novel candidate for UC treatment beyond endoscopic mucosal healing.