Fibrostricturing Crohn's disease is marked by an increase in active eosinophils in the deeper layers.

INTRODUCTION: Approximately 50% of Crohn's disease (CD) patients develop intestinal strictures necessitating surgery. The immune cell distribution in these strictures remains uncharacterized. We aimed to identify the immune cells in intestinal strictures of CD patients. METHODS: During ileocolonic resections, transmural sections of terminal ileum were sampled from 25 CD patients and 10 non-inflammatory bowel disease (IBD) controls. Macroscopically, unaffected, fibrostenotic and inflamed ileum was collected and analysed for immune cell distribution (flow cytometry) and protein expression. Collagen deposition was assessed via a Masson's Trichrome staining. Eosinophil and fibroblast co-localization was assessed through immunohistochemistry. RESULTS: The Masson's Trichrome staining confirmed augmented collagen deposition in both the fibrotic as the inflamed region, though with a significant increased collagen deposition in fibrotic compared to inflamed tissue. Distinct Th1, Th2, regulatory T cells, dendritic cells and monocytes were identified in fibrotic and inflamed CD ileum compared to unaffected ileum of CD patients as non-IBD controls. Only minor differences were observed between fibrotic and inflamed tissue, with more active eosinophils in fibrotic deeper layers and increased Eosinophil Cationic Protein (ECP) protein expression in inflamed deeper layers. Lastly, no differences in eosinophil and fibroblast co-localization was observed between the different regions. CONCLUSION: This study characterized immune cell distribution and protein expression in fibrotic and inflamed ileal tissue of CD patients. Immunologic, proteomic and histological data suggest inflammation and fibrosis are intertwined, with large overlap between both tissue types. However strikingly, we did identify an increased presence of active eosinophils only in the fibrotic deeper layers, suggesting their potential role in fibrosis development.

Efficacy and Safety of Ustekinumab for Chronic Pouchitis: A Prospective Open-label Multicenter Study.

BACKGROUND & AIMS: Seventeen percent of patients with ulcerative colitis that undergo proctocolectomy with pouch surgery will develop chronic pouchitis. We evaluated the efficacy of ustekinumab for these patients. METHODS: We performed a prospective study of patients with chronic pouchitis receiving ustekinumab intravenously at baseline (∼6 mg/kg) and 90 mg ustekinumab subcutaneously every 8 weeks thereafter. The Modified Pouchitis Disease Activity Index (mPDAI) was assessed at baseline and weeks 16 and 48. The primary endpoint was the proportion of patients achieving steroid-free remission (mPDAI <5 and reduction by ≥2 points) at week 16. Secondary endpoints included the proportion of patients achieving remission at week 48, the proportion of patients achieving response (reduction of mPDAI by ≥2 points) at weeks 16 and 48, and change in mPDAI. RESULTS: We enrolled 22 patients (59% male; median age, 42.2 years). Remission was achieved in 27.3% at week 16 and 36.4% at week 48. Response was achieved in 54.5% both at weeks 16 and 48. The median mPDAI decreased from 8 (interquartile range [IQR], 7-10) to 7 (IQR, 4-9) at week 16 (P = .007) and 4 (IQR, 1.75-7.25) at week 48 (P < .001). The clinical mPDAI subscore decreased from 3.5 (IQR, 2-4) to 2 (IQR, 1-3) at week 16 (P = .009) and 1 (IQR, 0-2.25) at week 48 (P = .001). The endoscopic mPDAI subscore decreased from 5.5 (IQR, 4-6) to 4 (IQR, 3-6) at week 16 (P = .032) and 3 (IQR, 1.75-4.25) at week 48 (P = .001). CONCLUSION: Ustekinumab was efficacious in one-half of the patients suffering from chronic pouchitis. Ustekinumab should therefore be positioned in the treatment algorithm of chronic pouchitis. (ClinicalTrials.gov Number NCT04089345).

Constitutional mismatch repair deficiency mimicking Lynch syndrome is associated with hypomorphic mismatch repair gene variants.

Lynch syndrome (LS) and constitutional mismatch repair deficiency (CMMRD) are distinct cancer syndromes caused, respectively, by mono- and bi-allelic germline mismatch repair (MMR) variants. LS predisposes to mainly gastrointestinal and genitourinary cancers in adulthood. CMMRD predisposes to brain, haematological, and LS-spectrum cancers from childhood. Two suspected LS patients with first cancer diagnosis aged 27 or 38 years were found to be homozygous for an MMR (likely) pathogenic variant, MSH6 c.3226C>T (p.(Arg1076Cys)), or variant of uncertain significance (VUS), MLH1 c.306G>A (p.(Glu102=)). MLH1 c.306G>A was shown to cause leaky exon 3 skipping. The apparent genotype-phenotype conflict was resolved by detection of constitutional microsatellite instability in both patients, a hallmark feature of CMMRD. A hypomorphic effect of these and other variants found in additional late onset CMMRD cases, identified by literature review, likely explains a LS-like phenotype. CMMRD testing in carriers of compound heterozygous or homozygous MMR VUS may find similar cases and novel hypomorphic variants. Individualised management of mono- and bi-allelic carriers of hypomorphic MMR variants is needed until we better characterise the associated phenotypes.

Multilevel Analysis of the Neovascularization and Integration Process of a Nonvascularized Rectus Fascia Transplantation.

Background: Failure to close the abdominal wall after intestinal transplantation (ITx) or multivisceral Tx remains a surgical challenge. An attractive method is the use of nonvascularized rectus fascia (NVRF) in which both layers of the donor abdominal rectus fascia are used as an inlay patch without vascular anastomosis. How this graft integrates over time remains unknown. The study aims to provide a multilevel analysis of the neovascularization and integration process of the NVRF. Methods: Three NVRF-Tx were performed after ITx. Clinical, radiological, histological, and immunological data were analyzed to get insights into the neovascularization and integration process of the NVRF. Moreover, cryogenic contrast-enhanced microfocus computed tomography (microCT) analysis was used for detailed reconstruction of the vasculature in and around the NVRF (3-dimensional histology). Results: Two men (31- and 51-y-old) and 1 woman (49-y-old) underwent 2 multivisceral Tx and 1 combined liver-ITx, respectively. A CT scan showed contrast enhancement around the fascia graft at 5 days post-Tx. At 6 weeks, newly formed blood vessels were visualized around the graft with Doppler ultrasound. Biopsies at 2 weeks post-Tx revealed inflammation around the NVRF and early fibrosis. At 6 months, classical 2-dimensional histological analysis of a biopsy confirmed integration of the fascia graft with strong fibrotic reaction without signs of rejection. A cryogenic contrast-enhanced microCT scan of the same biopsy revealed the presence of microvasculature, enveloping and penetrating the donor fascia. Conclusions: We showed clinical, histological, and microCT evidence of the neovascularization and integration process of the NVRF after Tx.

Histologic assessments in ulcerative colitis: the evidence behind a new endpoint in clinical trials.

INTRODUCTION: Treatment goals for ulcerative colitis (UC) are evolving from the achievement of clinical remission to more rigorous goals defined by endoscopic and histologic healing. Achievement of deeper remission targets aims to reduce the risk of colectomy, hospitalizations, and colorectal cancer. AREAS COVERED: This review covers histologic assessments, histologic remission as a clinical trial endpoint, and the association between histologic disease activity and clinical outcomes. Future directions are also discussed, including the use of advanced imaging and artificial intelligence technologies, as well as potential future treatment targets beyond histologic remission. EXPERT OPINION: Histologic assessments are used for their sensitivity in measuring mucosal inflammatory changes in UC. Due to correlation with disease activity, histologic assessments may support clinical decision-making regarding treatment decisions as such assessments can be associated with rates of clinical relapse, hospitalization, colectomy, and neoplasia. While histologic remission is limited by varying definitions and multiple histologic indices, work is ongoing to create a consensus on the use of histologic assessments in clinical trials. As research advances, aspirational targets beyond histologic remission, such as molecular healing and disease clearance, are being explored.

Ulcerative colitis (UC) is the most common inflammatory bowel disease and often results in bloody diarrhea, frequent bowel movements, and bowel urgency. Patients with UC are at greater risk for hospitalization, surgery, and colorectal cancer. To reduce these risks, the goals of UC treatment are changing from mainly addressing symptoms to reducing inflammation at a deeper histologic, or microscopic, level. The inflammation in UC causes distinct microscopic changes in the colon, which can be assessed after collecting biopsies or tissue samples. This review provides an overview of histologic remission (when no signs of inflammation are seen in tissue samples viewed under a microscope) as a treatment goal in UC.Histologic remission has been shown to be associated with lower rates of relapse, hospitalization, surgical removal of the colon, and colorectal cancer. However, using histologic remission as a treatment target can be difficult due to varying definitions and the many different scoring assessments available to healthcare providers. Updated guidance from regulatory agencies and academic organizations has helped align definitions of histologic remission and how to assess histologic healing in clinical trials.The introduction of targeted advanced therapies has allowed for deeper healing with the potential for histologic resolution. This enables clinicians and researchers to aim for treatment targets that are harder to achieve but have a greater impact for patients in the course of their disease. New technologies such as artificial intelligence, high-resolution endoscopy, and digital pathology have also led to targets beyond histologic healing, aiming to restore the function of the colon's mucosal barrier and disease clearance.

IDH1-mutated Crohn's disease-associated small bowel adenocarcinomas: Distinctive pathological features and association with MGMT methylation and serrated-type dysplasia.

AIMS: Patients with Crohn's disease (CrD) have an elevated risk for the development of small bowel adenocarcinomas (SBAs). Actionable isocitrate dehydrogenase 1 (IDH1) mutations have been reported to be more frequent in CrD-SBAs than in sporadic SBAs. The present study aimed to investigate the clinicopathological and immunophenotypical features, as well as methylation profiles, of IDH1-mutated CrD-SBAs. METHODS AND RESULTS: An international multicentre series of surgically resected CrD-SBAs was tested for IDH1 mutation. Clinicopathological features, immunophenotypical marker expression and O6-methylguanine-DNA methyltransferase (MGMT) and long interspersed nuclear element-1 (LINE-1) methylation were compared between IDH1-mutated and IDH1 wild-type CrD-SBAs. Ten (20%) of the 49 CrD-SBAs examined harboured an IDH1 mutation and all the mutated cancers harboured the R132C variant. Compared to IDH1 wild-type cases, IDH1-mutated CrD-SBAs showed significantly lower rates of cytokeratin 7 expression (P = 0.005) and higher rates of p53 overexpression (P = 0.012) and MGMT methylation (P = 0.012). All three dysplastic growths associated with IDH1-mutated SBAs harboured the same IDH1 variant (R132C) of the corresponding invasive cancer, and all were of non-conventional subtype (two serrated dysplastic lesions and one goblet cell-deficient dysplasia). In particular, non-conventional serrated dysplasia was significantly associated with IDH1-mutated CrD-SBAs (P = 0.029). No significant cancer-specific survival difference between IDH1-mutated CrD-SBA patients and IDH1 wild-type CrD-SBA patients was found (hazard ratio = 0.55, 95% confidence interval = 0.16-1.89; P = 0.313). CONCLUSIONS: IDH1-mutated CrD-SBAs, which represent approximately one-fifth of total cases, are characterised by distinctive immunophenotypical features and methylation profiles, with potential therapeutic implications. Moreover, IDH1-mutated non-conventional, serrated dysplasia is likely to represent a precursor lesion to such CrD-SBAs.

CD40 Ligand-CD40 Interaction Is an Intermediary between Inflammation and Angiogenesis in Proliferative Diabetic Retinopathy.

We aimed to investigate the role of the CD40-CD40 ligand (CD40L) pathway in inflammation-mediated angiogenesis in proliferative diabetic retinopathy (PDR). We analyzed vitreous fluids and epiretinal fibrovascular membranes from PDR and nondiabetic patients, cultures of human retinal microvascular endothelial cells (HRMECs) and Müller glial cells and rat retinas with ELISA, immunohistochemistry, flow cytometry and Western blot analysis. Functional tests included measurement of blood-retinal barrier breakdown, in vitro angiogenesis and assessment of monocyte-HRMEC adherence. CD40L and CD40 levels were significantly increased in PDR vitreous samples. We demonstrated CD40L and CD40 expression in vascular endothelial cells, leukocytes and myofibroblasts in epiretinal membranes. Intravitreal administration of soluble (s)CD40L in normal rats significantly increased retinal vascular permeability and induced significant upregulation of phospho-ERK1/2, VEGF, intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1). sCD40L induced upregulation of VEGF, MMP-9, MCP-1 and HMGB1 in cultured Müller cells and phospo-ERK1/2, p65 subunit of NF-ĸB, VCAM-1 and VEGF in cultured HRMECS. TNF-α induced significant upregulation of CD40 in HRMECs and Müller cells and VEGF induced significant upregulation of CD40 in HRMECs. sCD40L induced proliferation and migration of HRMECs. We provide experimental evidence supporting the involvement of the CD40L-CD40 pathway and how it regulates inflammatory angiogenesis in PDR.

Single cell dynamics of tumor specificity vs bystander activity in CD8+ T cells define the diverse immune landscapes in colorectal cancer.

CD8+ T cell activation via immune checkpoint blockade (ICB) is successful in microsatellite instable (MSI) colorectal cancer (CRC) patients. By comparison, the success of immunotherapy against microsatellite stable (MSS) CRC is limited. Little is known about the most critical features of CRC CD8+ T cells that together determine the diverse immune landscapes and contrasting ICB responses. Hence, we pursued a deep single cell mapping of CRC CD8+ T cells on transcriptomic and T cell receptor (TCR) repertoire levels in a diverse patient cohort, with additional surface proteome validation. This revealed that CRC CD8+ T cell dynamics are underscored by complex interactions between interferon-γ signaling, tumor reactivity, TCR repertoire, (predicted) TCR antigen-specificities, and environmental cues like gut microbiome or colon tissue-specific 'self-like' features. MSI CRC CD8+ T cells showed tumor-specific activation reminiscent of canonical 'T cell hot' tumors, whereas the MSS CRC CD8+ T cells exhibited tumor unspecific or bystander-like features. This was accompanied by inflammation reminiscent of 'pseudo-T cell hot' tumors. Consequently, MSI and MSS CRC CD8+ T cells showed overlapping phenotypic features that differed dramatically in their TCR antigen-specificities. Given their high discriminating potential for CD8+ T cell features/specificities, we used the single cell tumor-reactive signaling modules in CD8+ T cells to build a bulk tumor transcriptome classification for CRC patients. This "Immune Subtype Classification" (ISC) successfully distinguished various tumoral immune landscapes that showed prognostic value and predicted immunotherapy responses in CRC patients. Thus, we deliver a unique map of CRC CD8+ T cells that drives a novel tumor immune landscape classification, with relevance for immunotherapy decision-making.

Early versus Late Use of Vedolizumab in Ulcerative Colitis: Clinical, Endoscopic, and Histological Outcomes.

BACKGROUND AND AIMS: We explored the potential for differential efficacy of vedolizumab between "early" and "late" ulcerative colitis (UC) with evaluation of clinical, endoscopic, and histological endpoints. METHODS: This was a multicentre, multinational open-label study in patients with moderately-to-severely active UC, defining "early" UC by a disease duration <4 years and bio-naïve and "late" UC by a disease duration >4 years and additional exposure to tumour necrosis factor antagonists. Patients received standard treatment with intravenous vedolizumab for 52 weeks (300 mg weeks 0-2-6, every 8 weeks thereafter without escalation). The primary endpoint was corticosteroid-free clinical remission with endoscopic improvement (total Mayo score ≤2 with no subscore >1) at both week 26 and 52. RESULTS: A total of 121 patients were included: in the "early" group 25/59 (42.4%) achieved the primary endpoint versus 19/62 (30.6%) in the "late" group (P = 0.18). There were no significant differences between the two groups in endoscopic improvement (week 26: "early" 32/59 [54.2%] vs. "late" 29/62 [46.8%]; P = 0.412; week 52: 27/59 [45.8%] vs. 25/62 [40.3%]; P = 0.546) or histological remission (Robarts Histopathology Index <3 without neutrophils in the epithelium and lamina propria) (week 26: 24/59 [40.7%] vs. 21/62 [33.9%]; P = 0.439; week 52: 22/59 [37.3%] vs. 22/62 [35.5%]; P = 0.837). CONCLUSIONS: No significant differences in clinical, endoscopic, and histological outcomes were observed between "early" and "late" disease.

INT-767-A Dual Farnesoid-X Receptor (FXR) and Takeda G Protein-Coupled Receptor-5 (TGR5) Agonist Improves Survival in Rats and Attenuates Intestinal Ischemia Reperfusion Injury.

Intestinal ischemia is a potentially catastrophic emergency, with a high rate of morbidity and mortality. Currently, no specific pharmacological treatments are available. Previous work demonstrated that pre-treatment with obeticholic acid (OCA) protected against ischemia reperfusion injury (IRI). Recently, a more potent and water-soluble version has been synthesized: Intercept 767 (INT-767). The aim of this study was to investigate if intravenous treatment with INT-767 can improve outcomes after IRI. In a validated rat model of IRI (60 min ischemia + 60 min reperfusion), three groups were investigated (n = 6/group): (i) sham: surgery without ischemia; (ii) IRI + vehicle; and (iii) IRI + INT-767. The vehicle (0.9% NaCl) or INT-767 (10 mg/kg) were administered intravenously 15 min after start of ischemia. Endpoints were 7-day survival, serum injury markers (L-lactate and I-FABP), histology (Park-Chiu and villus length), permeability (transepithelial electrical resistance and endotoxin translocation), and cytokine expression. Untreated, IRI was uniformly lethal by provoking severe inflammation and structural damage, leading to translocation and sepsis. INT-767 treatment significantly improved survival by reducing inflammation and preserving intestinal structural integrity. This study demonstrates that treatment with INT-767 15 min after onset of intestinal ischemia significantly decreases IRI and improves survival. The ability to administer INT-767 intravenously greatly enhances its clinical potential.

Appearance of the Bowel and Mesentery During Surgery Is Not Predictive of Postoperative Recurrence After Ileocecal Resection for Crohn's Disease: A Prospective Monocentric Study.

BACKGROUND: Very few risk factors for postoperative recurrence (POR) of Crohn's Disease (CD) after ileocecal resection have been identified. The aim of the present study was to verify the association between an a priori defined list of intraoperative macroscopic findings and POR. METHODS: This was a prospective observational study including patients undergoing primary ileocecal resection for CD. Four intraoperative factors were independently evaluated by 2 surgeons: length of resected ileum, mesentery thickness, presence of areas of serosal fat infiltration, or abnormal serosal vasodilation on normal bowel proximal to the resected bowel. The primary end point was early endoscopic POR at month 6 and defined as modified Rutgeerts score ≥i2b. Secondary end points were clinical and surgical recurrence. RESULTS: Between September 2020 and November 2022, 83 consecutive patients were included. Early endoscopic recurrence occurred in 45 of 76 patients (59.2%). Clinical and biochemical recurrence occurred in 17.3% (95% confidence interval, [CI], 10.4%-28.0%) and 14.6% of the patients after 12 months. The risk of developing endoscopic and clinical recurrence was 1.127 (95% CI, 0.448;2.834, P = .799) and 0.896 (95% CI, 0.324-2.478, P = .832) when serosal fat infiltration was observed, and 1.388 (95% CI, 0.554-3.476, P = .484), and 1.153 (95% CI, 0.417;3.187, P = .783) when abnormal serosal vasodilation was observed. Similarly, length of the resected bowel and mesentery thickness showed no association with POR. A subgroup analysis on patients who received no postoperative medical prophylaxis did not identify any risk factor for endoscopic POR. CONCLUSIONS: The macroscopic appearance of the bowel and associated mesentery during surgery does not seem to be predictive of POR after ileocecal resection for CD.

Prospective studies investigating risk factors for Crohn's disease recurrence after surgery are scarce. In a prospective cohort of 83 patients undergoing primary ileocecal resection, no association between few intraoperative macroscopic findings and postoperative endoscopic/clinical recurrence was observed.

Macrophage-Myofibroblast Transition Contributes to Myofibroblast Formation in Proliferative Vitreoretinal Disorders.

Inflammation and fibrosis are key features of proliferative vitreoretinal disorders. We aimed to define the macrophage phenotype and investigate the role of macrophage-myofibroblast transition (MMT) in the contribution to myofibroblast populations present in epiretinal membranes. Vitreous samples from proliferative diabetic retinopathy (PDR), proliferative vitreoretinopathy (PVR) and nondiabetic control patients, epiretinal fibrovascular membranes from PDR patients and fibrocellular membranes from PVR patients, human retinal Müller glial cells and human retinal microvascular endothelial cells (HRMECs) were studied by ELISA, immunohistochemistry and flow cytometry analysis. Myofibroblasts expressing α-SMA, fibroblast activation protein-α (FAP-α) and fibroblast-specific protein-1 (FSP-1) were present in all membranes. The majority of CD68+ monocytes/macrophages co-expressed the M2 macrophage marker CD206. In epiretinal membranes, cells undergoing MMT were identified by co-expression of the macrophage marker CD68 and myofibroblast markers α-SMA and FSP-1. Further analysis revealed that CD206+ M2 macrophages co-expressed α-SMA, FSP-1, FAP-α and ß-catenin. Soluble (s) CD206 and sFAP-α levels were significantly higher in vitreous samples from PDR and PVR patients than in nondiabetic control patients. The proinflammatory cytokine TNF-α and the hypoxia mimetic agent cobalt chloride induced upregulation of sFAP-α in culture media of Müller cells but not of HRMECs. The NF-Ä¸ß inhibitor BAY11-7085 significantly attenuated TNF-α-induced upregulation of sFAP-α in Müller cells. Our findings suggest that the process of MMT might contribute to myofibroblast formation in epiretinal membranes, and this transition involved macrophages with a predominant M2 phenotype. In addition, sFAP-α as a vitreous biomarker may be derived from M2 macrophages transitioned to myofibroblasts and from Müller cells.

A Pathology-based Case Series of Influenza- and COVID-19-associated Pulmonary Aspergillosis: The Proof Is in the Tissue.

Rationale: Invasive pulmonary aspergillosis has emerged as a frequent coinfection in severe coronavirus disease (COVID-19), similarly to influenza, yet the clinical invasiveness is more debated. Objectives: We investigated the invasive nature of pulmonary aspergillosis in histology specimens of influenza and COVID-19 ICU fatalities in a tertiary care center. Methods: In this monocentric, descriptive, retrospective case series, we included adult ICU patients with PCR-proven influenza/COVID-19 respiratory failure who underwent postmortem examination and/or tracheobronchial biopsy during ICU admission from September 2009 until June 2021. Diagnosis of probable/proven viral-associated pulmonary aspergillosis (VAPA) was made based on the Intensive Care Medicine influenza-associated pulmonary aspergillosis and the European Confederation of Medical Mycology (ECMM) and the International Society for Human and Animal Mycology (ISHAM) COVID-19-associated pulmonary aspergillosis consensus criteria. All respiratory tissues were independently reviewed by two experienced pathologists. Measurements and Main Results: In the 44 patients of the autopsy-verified cohort, 6 proven influenza-associated and 6 proven COVID-19-associated pulmonary aspergillosis diagnoses were identified. Fungal disease was identified as a missed diagnosis upon autopsy in 8% of proven cases (n = 1/12), yet it was most frequently found as confirmation of a probable antemortem diagnosis (n = 11/21, 52%) despite receiving antifungal treatment. Bronchoalveolar lavage galactomannan testing showed the highest sensitivity for VAPA diagnosis. Among both viral entities, an impeded fungal growth was the predominant histologic pattern of pulmonary aspergillosis. Fungal tracheobronchitis was histologically indistinguishable in influenza (n = 3) and COVID-19 (n = 3) cases, yet macroscopically more extensive at bronchoscopy in influenza setting. Conclusions: A proven invasive pulmonary aspergillosis diagnosis was found regularly and with a similar histological pattern in influenza and in COVID-19 ICU case fatalities. Our findings highlight an important need for VAPA awareness, with an emphasis on mycological bronchoscopic work-up.

Mismatch repair deficiency as prognostic factor for stage III small bowel adenocarcinoma: A multicentric international study.

BACKGROUND: Small bowel adenocarcinoma (SBA) is a rare cancer with an aggressive behavior. No study has specifically addressed the putative prognostic role of mismatch repair status in stage III SBAs. AIMS: We aimed to investigate whether mismatch repair deficiency is associated with cancer-specific survival in a Western cohort of patients with stage III SBAs. METHODS: In this retrospective multicentric international cohort study, we enrolled 70 patients who underwent surgically resection for stage III SBAs and we analyzed the frequency of mismatch repair deficiency, tested by immunohistochemistry for mismatch repair proteins and by polymerase chain reaction for microsatellite instability, and its association with cancer-specific survival and other clinic-pathologic factors. RESULTS: We found sixteen (23%) patients with mismatch repair deficient adenocarcinoma, without discordance between immunohistochemical and polymerase chain reaction for microsatellite instability analyses. Mismatch repair deficiency proved to be associated with a better outcome both at univariable analysis (hazard ratio: 0.28, 95% confidence interval: 0.08-0.91, p: 0.035) and in bivariable models adjusted for patient age or gender, tumor site, pT4 stage, tumor budding, and perineural invasion. CONCLUSION: This study highlights the importance of testing mismatch repair status to improve prognostic stratification in stage III SBAs.

Artificial Intelligence Enabled Histological Prediction of Remission or Activity and Clinical Outcomes in Ulcerative Colitis.

BACKGROUND & AIMS: Microscopic inflammation has significant prognostic value in ulcerative colitis (UC); however, its assessment is complex with high interobserver variability. We aimed to develop and validate an artificial intelligence (AI) computer-aided diagnosis system to evaluate UC biopsies and predict prognosis. METHODS: A total of 535 digitalized biopsies (273 patients) were graded according to the PICaSSO Histologic Remission Index (PHRI), Robarts, and Nancy Histological Index. A convolutional neural network classifier was trained to distinguish remission from activity on a subset of 118 biopsies, calibrated on 42 and tested on 375. The model was additionally tested to predict the corresponding endoscopic assessment and occurrence of flares at 12 months. The system output was compared with human assessment. Diagnostic performance was reported as sensitivity, specificity, prognostic prediction through Kaplan-Meier, and hazard ratios of flares between active and remission groups. We externally validated the model in 154 biopsies (58 patients) with similar characteristics but more histologically active patients. RESULTS: The system distinguished histological activity/remission with sensitivity and specificity of 89% and 85% (PHRI), 94% and 76% (Robarts Histological Index), and 89% and 79% (Nancy Histological Index). The model predicted the corresponding endoscopic remission/activity with 79% and 82% accuracy for UC endoscopic index of severity and Paddington International virtual ChromoendoScopy ScOre, respectively. The hazard ratio for disease flare-up between histological activity/remission groups according to pathologist-assessed PHRI was 3.56, and 4.64 for AI-assessed PHRI. Both histology and outcome prediction were confirmed in the external validation cohort. CONCLUSION: We developed and validated an AI model that distinguishes histologic remission/activity in biopsies of UC and predicts flare-ups. This can expedite, standardize, and enhance histologic assessment in practice and trials.

A Phase 2b, Randomised, Double-blind, Placebo-controlled, Parallel-arm, Multicenter Study Evaluating the Safety and Efficacy of Tesnatilimab in Patients with Moderately to Severely Active Crohn's Disease.

BACKGROUND AND AIMS: Tesnatilimab, a monoclonal antibody targeting NKG2D, was evaluated in Crohn's disease [CD] patients who had failed or were intolerant to biologic or conventional therapy. METHODS: TRIDENT was a phase 2b, two-part, randomised, double-blind, placebo-controlled, parallel-arm, multicenter study. In Part 1 [proof of concept], 145 patients who were biologic intolerant or refractory [Bio-IR] or had not failed biologic therapy [Bio-NF] were randomised in a 1:1 ratio to placebo subcutaneously [SC] or tesnatilimab 400 mg SC. In Part 2 [dose ranging], 243 Bio-IR and Bio-NF patients were randomised in a 1:1:1:1:1 ratio to placebo, tesnatilimab [50 mg, 150 mg, 400 mg], or intravenous infusion of ustekinumab ~6 mg/kg at Week 0 and 90 mg SC at Weeks 8 and 16. The primary endpoint was mean change from baseline in Crohn's Disease Activity Index [CDAI] at Week 8 [Part 1] and Week 12 [Part 2]. Clinical and endoscopic remission/response were evaluated. Efficacy analyses were also assessed by NKG2D and MICB single nucleotide polymorphism [SNP] status [SNP-positive means positive in at least one of two SNPs]. Safety events were summarised. RESULTS: In Part 1, mean change from baseline in CDAI score was significantly greater with tesnatilimab vs placebo at Week 8 [-103.6 vs -60.0; p < 0.01]. In Part 2, no dose-response signal was detected. Mean changes from baseline in CDAI at Week 12 were -93.2, -72.2, and -84.3 for low, middle, and high doses of tesnatilimab, respectively, vs -59.2 for placebo and -148.8 for ustekinumab. Similar reductions from baseline in CDAI score were observed in patients receiving tesnatilimab, regardless of SNP status. Clinical remission rates were greater with tesnatilimab than placebo in Parts 1 and 2, whereas endoscopic response rates were greater with tesnatilimab only in Part 1. No unexpected safety events occurred. CONCLUSIONS: Tesnatilimab was well tolerated. The efficacy of tesnatilimab in patients with CD was significant for the primary endpoint in Part 1; however, no dose-response signal was detected for the primary endpoint in Part 2. Based on these inconsistent findings, tesnatilimab was not considered an effective treatment for patients with CD and no further development is planned. CLINICALTRIALS.GOV IDENTIFIER: NCT02877134.

Mucorales PCR in blood as an early marker of invasive gastrointestinal mucormycosis might decrease the delay in treatment: A case report.

We describe the fatal case of a patient with gastric perforation due to ischemia and necrosis of the stomach secondary to generalized vascular thrombosis following allogeneic hematopoietic cell transplantation. Histopathological examination of the resected stomach, spleen and omentum unexpectedly showed fungal hyphae suggestive of invasive mucormycosis. We retrospectively performed Mucorales PCR (MucorGenius®, PathoNostics, Maastricht, The Netherlands) in blood and tissue samples of this patient. The PCR was positive 16 days before time of death and 9 days before abdominal pain.

Wide-area transepithelial sampling with computer-assisted analysis to detect high grade dysplasia and cancer in Barrett's esophagus: a multicenter randomized study.

BACKGROUND: Current surveillance for Barrett's esophagus (BE), consisting of four-quadrant random forceps biopsies (FBs), has an inherent risk of sampling error. Wide-area transepithelial sampling (WATS) may increase detection of high grade dysplasia (HGD) and esophageal adenocarcinoma (EAC). In this multicenter randomized trial, we aimed to evaluate WATS as a substitute for FB. METHODS: Patients with known BE and a recent history of dysplasia, without visible lesions, at 17 hospitals were randomized to receive either WATS followed by FB or vice versa. All WATS samples were examined, with computer assistance, by at least two experienced pathologists at the CDx Diagnostics laboratory. Similarly, all FBs were examined by two expert pathologists. The primary end point was concordance/discordance for detection of HGD/EAC between the two techniques. RESULTS: 172 patients were included, of whom 21 had HGD/EAC detected by both modalities, 18 had HGD/EAC detected by WATS but missed by FB, and 12 were detected by FB but missed by WATS. The detection rate of HGD/EAC did not differ between WATS and FB (P = 0.36). Using WATS as an adjunct to FB significantly increased the detection of HGD/EAC vs. FB alone (absolute increase 10 % [95 %CI 6 % to 16 %]). Mean procedural times in minutes for FB alone, WATS alone, and the combination were 6.6 (95 %CI 5.9 to 7.1), 4.9 (95 %CI 4.1 to 5.4), and 11.2 (95 %CI 10.5 to 14.0), respectively. CONCLUSIONS: Although the combination of WATS and FB increases dysplasia detection in a population of BE patients enriched for dysplasia, we did not find a statistically significant difference between WATS and FB for the detection of HGD/EAC as single modality.

Pleural decortication and hyperthermic intrathoracic chemotherapy for pseudomyxoma.

Aim: Pleural dissemination of pseudomyxoma peritonei (PMP) is an extremely rare diagnosis, for which no standard therapy is available.Methods: We describe the successful treatment of a 67-year-old male diagnosed with left-sided intrapleural dissemination of PMP (low-grade appendiceal mucinous neoplasm), 2 years after treatment of abdominal PMP with cytoreductive surgery (CRS) and hyperthermic intra-peritoneal chemotherapy. Treatment consisted of extended pleural decortication (ePD) and oxaliplatin-based hyperthermic intrathoracic chemotherapy (HITHOC). The patient is doing well without complications or signs of recurrence, 26 months after thoracic surgery.Conclusion: ePD in combination with HITHOC is a valuable treatment for thoracic PMP.

Differential Expression and Localization of ADAMTS Proteinases in Proliferative Diabetic Retinopathy.

We analyzed the expression of ADAMTS proteinases ADAMTS-1, -2, -4, -5 and -13; their activating enzyme MMP-15; and the degradation products of proteoglycan substrates versican and biglycan in an ocular microenvironment of proliferative diabetic retinopathy (PDR) patients. Vitreous samples from PDR and nondiabetic patients, epiretinal fibrovascular membranes from PDR patients, rat retinas, retinal Müller glial cells and human retinal microvascular endothelial cells (HRMECs) were studied. The levels of ADAMTS proteinases and MMP-15 were increased in the vitreous from PDR patients. Both full-length and cleaved activation/degradation fragments of ADAMTS proteinases were identified. The amounts of versican and biglycan cleavage products were increased in vitreous from PDR patients. ADAMTS proteinases and MMP-15 were localized in endothelial cells, monocytes/macrophages and myofibroblasts in PDR membranes, and ADAMTS-4 was expressed in the highest number of stromal cells. The angiogenic activity of PDR membranes correlated significantly with levels of ADAMTS-1 and -4 cellular expression. ADAMTS proteinases and MMP-15 were expressed in rat retinas. ADAMTS-1 and -5 and MMP-15 levels were increased in diabetic rat retinas. HRMECs and Müller cells constitutively expressed ADAMTS proteinases but not MMP-15. The inhibition of NF-κB significantly attenuated the TNF-α-and-VEGF-induced upregulation of ADAMTS-1 and -4 in a culture medium of HRMECs and Müller cells. In conclusion, ADAMTS proteinases, MMP-15 and versican and biglycan cleavage products were increased in the ocular microenvironment of patients with PDR.