Acute cytomegalovirus infection modulates the intestinal microbiota and targets intestinal epithelial cells.

Primary and recurrent cytomegalovirus (CMV) infections frequently cause CMV colitis in immunocompromised as well as inflammatory bowel disease (IBD) patients. Additionally, colitis occasionally occurs upon primary CMV infection in patients who are apparently immunocompetent. In both cases, the underlying pathophysiologic mechanisms are largely elusive - in part due to the lack of adequate access to specimens. We employed the mouse cytomegalovirus (MCMV) model to assess the association between CMV and colitis. During acute primary MCMV infection of immunocompetent mice, the gut microbial composition was affected as manifested by an altered ratio of the Firmicutes to Bacteroidetes phyla. Interestingly, these microbial changes coincided with high-titer MCMV replication in the colon, crypt hyperplasia, increased colonic pro-inflammatory cytokine levels, and a transient increase in the expression of the antimicrobial protein Regenerating islet-derived protein 3 gamma (Reg3γ). Further analyses revealed that murine and human intestinal epithelial cell lines, as well as primary intestinal crypt cells and organoids represent direct targets of CMV infection causing increased cell death. Accordingly, in vivo MCMV infection disrupted the intestinal epithelial barrier and increased apoptosis of intestinal epithelial cells. In summary, our data show that CMV transiently induces colitis in immunocompetent hosts by altering the intestinal homeostasis.

Intestinal Ultrasound Is Accurate to Determine Endoscopic Response and Remission in Patients With Moderate to Severe Ulcerative Colitis: A Longitudinal Prospective Cohort Study.

BACKGROUND & AIMS: Intestinal ultrasound (IUS) is noninvasive, cost-effective, and accurate to determine disease activity in ulcerative colitis (UC). In this study, we prospectively evaluated IUS for treatment response in a longitudinal cohort by using endoscopy and histology as gold standards. METHODS: Consecutive patients with moderate to severe UC (endoscopic Mayo score [EMS] ≥2) starting tofacitinib treatment were included. Patients were evaluated at baseline and after 8 weeks of tofacitinib induction by means of clinical, biochemical, endoscopic (EMS and UC endoscopic index for severity), histologic (Robarts Histopathologic Index) and IUS assessments. Readers of IUS, endoscopy, and histology were blinded for all other outcomes. The primary outcome was difference in bowel wall thickness (BWT) for endoscopic improvement vs no endoscopic improvement. Endoscopic remission was defined as EMS = 0, improvement as EMS ≤1, and response as a decrease of EMS ≥1. RESULTS: Thirty patients were included, with 27 patients completing follow-up. BWT correlated with EMS (ρ = 0.68, P < .0001), UC endoscopic index for severity (ρ = 0.73, P < .0001) and Robarts Histopathologic Index (ρ = 0.49, P = .002) at both time points. BWT in the sigmoid was lower in patients with endoscopic remission (1.4 mm vs 4.0 mm, P = .016), endoscopic improvement (1.8 mm vs 4.5 mm, P < .0001) and decrease in BWT was more pronounced in patients with endoscopic response (-58.1% vs -13.4%, P = .018). The most accurate cutoff values for BWT were 2.8 mm (area under the curve [AUC] 0.87) for endoscopic remission, 3.9 mm (AUC 0.92) for improvement, and decrease of 32% (AUC 0.87) for response. The submucosa was the most responsive wall layer. CONCLUSION: IUS, importantly BWT as the single most important parameter, is highly accurate to detect treatment response when evaluated against endoscopic outcomes.

Increased Proportion of Colorectal Cancer in Patients With Ulcerative Colitis Undergoing Surgery in the Netherlands.

INTRODUCTION: The aim of the current study was to assess whether there is an indication shift for surgery in patients with ulcerative colitis (UC) from refractory disease to malignant degeneration over the past 3 decades. METHODS: All patients with histologically confirmed UC who underwent a colorectal resection between 1991 and 2020 were extracted from the nationwide Dutch Pathology Registry. The primary outcome was the proportion of colorectal cancer (CRC) in the colon specimens. Outcomes were compared between 3 periods (P1: 1991-2000, P2: 2001-2010, and P3: 2011-2020). RESULTS: Overall, 6,094 patients with UC were included of which 4,854 underwent a (procto)colectomy and 1,240 a segmental resection. In 1,031 (16.9%) patients, CRC was demonstrated in the pathological resection specimen after a median disease duration of 11 years (IQR 3.0-19.0). The proportion of CRC increased from 11.3% in P1, to 16.1% in P2, and 22.8% in P3 ( P < 0.001). Median disease duration at the time of resection increased from 4 years in P1, to 10 years in P2, and 17 years in P3 ( P < 0.001). The proportion of patients diagnosed with advanced malignancy (pT3/T4) (P1: 61.2% vs P2: 65.2% vs P3: 62.4%, respectively, P = 0.633) and lymph node metastasis (N+) (P1: 33.0% vs P2: 41.9% vs P3: 38.2%, respectively, P = 0.113) did not change over time. DISCUSSION: This nationwide pathology study demonstrated an increased proportion of surgery for CRC over the past 3 decades. We hypothesize that the expanding therapeutic armamentarium for UC leads to exhausting medical options and hence postponed colectomy. This, however, might be at the expense of an increased risk of CRC in the long term.

Prognostic Value of T-Cell Density in the Tumor Center and Outer Margins in Gastric Cancer.

Tumor-infiltrating lymphocytes are associated with the survival of gastric cancer patients. T-cell densities in the tumor and its periphery were previously identified as prognostic T-cell markers for resectable gastric cancer. Immunohistochemistry for 5 T-cell markers, CD3, CD45RO, CD8, FOXP3, and granzyme B was performed on serial sections of N = 251 surgical resection specimens of patients treated with surgery only in the D1/D2 trial. Positive T cells were digitally quantified into tiles of 0.25 mm2 across 3 regions: the tumor center (TC), the inner invasive margin, and the outer invasive margin (OIM). A classification and regression tree model was employed to identify the optimal combination of median T-cell densities per region with cancer-specific survival (CSS) as the outcome. All statistical tests were 2-sided. CD8OIM was identified as the most dominant prognostic factor, followed by FOXP3TC, resulting in a decision tree containing 3 prognostically distinct subgroups with high (Hi) or low (Lo) density of the markers: CD8OIMHi, CD8OIMLo/FOXP3TCHi, and CD8OIMLo/FOXP3TCLo. In a multivariable Cox regression analysis, which included pathological T and N stages, Lauren histologic types, EBV status, microsatellite instability, and type of surgery, the immune subgroups were independent predictors for CSS. CSS was lower for CD8OIMLo/FOXP3TCHi (HR: 5.02; 95% CI: 2.03-12.42) and for CD8OIMLo/FOXP3TCLo (HR: 7.99; 95% CI: 3.22-19.86), compared with CD8OIMHi (P < .0001). The location and density of both CD8+ and FOXP3+ T cells in resectable gastric cancer are independently associated with survival. The combination of CD8OIM and FOXP3TC T-cell densities is a promising stratification factor that should be validated in independent studies.

Pathologist Computer-Aided Diagnostic Scoring of Tumor Cell Fraction: A Swiss National Study.

Tumor cell fraction (TCF) estimation is a common clinical task with well-established large interobserver variability. It thus provides an ideal test bed to evaluate potential impacts of employing a tumor cell fraction computer-aided diagnostic (TCFCAD) tool to support pathologists' evaluation. During a National Slide Seminar event, pathologists (n = 69) were asked to visually estimate TCF in 10 regions of interest (ROIs) from hematoxylin and eosin colorectal cancer images intentionally curated for diverse tissue compositions, cellularity, and stain intensities. Next, they re-evaluated the same ROIs while being provided a TCFCAD-created overlay highlighting predicted tumor vs nontumor cells, together with the corresponding TCF percentage. Participants also reported confidence levels in their assessments using a 5-tier scale, indicating no confidence to high confidence, respectively. The TCF ground truth (GT) was defined by manual cell-counting by experts. When assisted, interobserver variability significantly decreased, showing estimates converging to the GT. This improvement remained even when TCFCAD predictions deviated slightly from the GT. The standard deviation (SD) of the estimated TCF to the GT across ROIs was 9.9% vs 5.8% with TCFCAD (P < .0001). The intraclass correlation coefficient increased from 0.8 to 0.93 (95% CI, 0.65-0.93 vs 0.86-0.98), and pathologists stated feeling more confident when aided (3.67 ± 0.81 vs 4.17 ± 0.82 with the computer-aided diagnostic [CAD] tool). TCFCAD estimation support demonstrated improved scoring accuracy, interpathologist agreement, and scoring confidence. Interestingly, pathologists also expressed more willingness to use such a CAD tool at the end of the survey, highlighting the importance of training/education to increase adoption of CAD systems.

Response to neoadjuvant chemotherapy and survival in molecular subtypes of resectable gastric cancer: a post hoc analysis of the D1/D2 and CRITICS trials.

BACKGROUND: Epstein-Barr virus positivity (EBV+) and microsatellite instability (MSI-high) are positive prognostic factors for survival in resectable gastric cancer (GC). However, benefit of perioperative treatment in patients with MSI-high tumors remains topic of discussion. Here, we present the clinicopathological outcomes of patients with EBV+, MSI-high, and EBV-/MSS GCs who received either surgery only or perioperative treatment. METHODS: EBV and MSI status were determined on tumor samples collected from 447 patients treated with surgery only in the D1/D2 trial, and from 451 patients treated perioperatively in the CRITICS trial. Results were correlated to histopathological response, morphological tumor characteristics, and survival. RESULTS: In the D1/D2 trial, 5-year cancer-related survival was 65.2% in 47 patients with EBV+, 56.7% in 47 patients with MSI-high, and 47.6% in 353 patients with EBV-/MSS tumors. In the CRITICS trial, 5-year cancer-related survival was 69.8% in 25 patients with EBV+, 51.7% in 27 patients with MSI-high, and 38.6% in 402 patients with EBV-/MSS tumors. Interestingly, all three MSI-high tumors with moderate to complete histopathological response (3/27, 11.1%) had substantial mucinous differentiation. No EBV+ tumors had a mucinous phenotype. 115/402 (28.6%) of EBV-/MSS tumors had moderate to complete histopathological response, of which 23/115 (20.0%) had a mucinous phenotype. CONCLUSIONS: In resectable GC, MSI-high had favorable outcome compared to EBV-/MSS, both in patients treated with surgery only, and in those treated with perioperative chemo(radio)therapy. Substantial histopathological response was restricted to mucinous MSI-high tumors. The mucinous phenotype might be a relevant parameter in future clinical trials for MSI-high patients.

Utility of gastric and duodenal biopsy sampling in adult eosinophilic esophagitis patients to rule out other gastrointestinal disorders.

RATIONALE: According to consensus guidelines, if eosinophilic esophagitis (EoE) is suspected, not only esophageal but also gastric and duodenal biopsy specimens should be sampled in order to exclude other generalized or eosinophilic gastrointestinal (GI) disorders, such as eosinophilic gastroenteritis or celiac disease. However, the diagnostic yield for this remains unclear. AIM: To assess the diagnostic yield of biopsy sampling from the stomach and duodenum in adult EoE patients to rule out generalized or eosinophilic GI disorders. METHODS: A retrospective chart-review was conducted in untreated adult EoE patients that underwent upper endoscopy with biopsies sampled from the esophagus, stomach and duodenum. Standardized (electronic) case-report forms were used to extract clinical, endoscopic and histologic data. RESULTS: In total, 93 adults (71% males, age 36.4 (interquartile range 28.4 - 49.1) years) with untreated EoE (≥15 eosinophils/high-power-field) were included. Symptoms of dysphagia and food impaction were reported in 93% and 58%, respectively of the patients. Typical endoscopic EoE-features were present in 77 (85%) patients. The yield of routinely sampled gastric and duodenal biopsy specimens in our cohort was 3.6% (95% confidence interval: 2.6-4.8%) (n/N = 1/93) for a relevant other generalized or eosinophilic GI diagnosis and 30% for other histological diagnosis such as non-specific or H. Pylori gastritis. In total, 62 (67%) patients presented with other GI symptoms and/or endoscopic abnormalities of the stomach and/or duodenum - which both may be suggestive for other relevant GI conditions. The diagnostic yield for a relevant generalized or eosinophilic GI disorder in this subgroup was, 4.8% (95%CI 3.4 - 6.7%) (n/N = 1/62). CONCLUSION: Gastric and duodenal biopsy specimens seem to have limited diagnostic value for the exclusion of generalized or eosinophilic GI disorders in adults with EoE.KEY POINTSEvidence is lacking on the diagnostic value of additional biopsies sampled form the stomach and duodenum to rule out other relevant generalized or eosinophilic gastrointestinal (GI) disorders.The yield of gastric and duodenal biopsies routinely sampled in our cohort was 3.6% for a relevant other generalized or eosinophilic GI diagnosis and 30% for other histological diagnosis such as non-specific or H. Pylori gastritis.The diagnostic yield for a relevant generalized or eosinophilic GI disorder in the subgroup of patients (67%) presenting with other GI symptoms and/or endoscopic abnormalities of the stomach and/or duodenum - which both may be suggestive for other relevant GI conditions was, 4.8%.Gastric and duodenal biopsy specimens seem to have limited diagnostic value for the exclusion of generalized or eosinophilic GI disorders in adults with EoE.

Leaflet Mechanical Properties of Carpentier-Edwards Perimount Magna Pericardial Aortic Bioprostheses.

BACKGROUND: Transcatheter aortic valve replacement (TAVR) has recently been shown to be equivalent to surgical aortic valve replacement (SAVR) in intermediate-risk patients. As TAVR expands towards the traditionally SAVR population, TAVR versus SAVR durability becomes increasingly important. While the durability of TAVR is unknown, valve design - particularly with regards to leaflet stress - impacts on valve durability. Although leaflet stress cannot be measured directly, it can be determined using finite element modeling, with such models requiring the mechanical properties of the leaflets. Balloon-expandable TAVR involves the use of bovine pericardial leaflets treated in the same manner as surgical bioprosthetic leaflets. The study aim was to determine the leaflet mechanical properties of Carpentier-Edwards bioprostheses for future TAVR and SAVR computational models. METHODS: A total of 35 leaflets were excised from 12 Carpentier-Edwards Model 3000TFX Perimount Magna aortic bioprostheses (21 mm, 23 mm, and 25 mm) and subjected to displacement-controlled equibiaxial stretch testing. The stress-strain data acquired were fitted to a Fung constitutive model to describe the material properties in circumferential and radial directions. Leaflet stiffness was calculated at specified physiological stress, corresponding to zero pressure, systemic pressure, and between zero and systemic pressure. RESULTS: The 21-mm bioprostheses had significantly thinner leaflets than the larger bioprostheses. A non-linear stress-strain relationship was observed in all leaflets along the circumferential and radial directions. No significant difference in leaflet stiffness at systemic pressure, or between zero and systemic pressure, was found among the three bioprosthesis sizes. However, the leaflets from the 23 mm bioprosthesis were significantly more compliant than those of the 21 mm and 25 mm bioprostheses at zero pressure in the circumferential direction. No differences were observed in leaflet stiffness in circumferential versus radial directions. CONCLUSIONS: The bovine pericardial leaflets from Carpentier-Edwards Perimount Magna bioprostheses showed no differences in material properties among different valve sizes at systemic pressure. The thinner 21 mm leaflets did not show any corresponding differences in leaflet stiffness, which suggests that the thinner TAV leaflets may have a similar stiffness to their thicker SAV counterparts.

Bicuspid Aortic Valve-Associated Ascending Thoracic Aortic Aneurysm: Patient-Specific Finite Element Analysis.

BACKGROUND: Elective repair of bicuspid aortic valve (BAV)-associated ascending thoracic aortic aneurysm (aTAA) is recommended at lower size limits than tricuspid aortic valve (TAV)-associated aTAA. Rupture/dissection can occur when wall stress exceeds wall strength. Previously, a validated computational method was developed for determining aTAA wall stress, but to date this method has not applied to a patient-specific BAV aTAA. The study aim was to develop a patient-specific BAV aTAA computational model to determine regional wall stress, using the required zero-pressure geometry, wall thickness, material properties, and residual stress. METHODS: A BAV aTAA specimen was excised intact during elective repair, and zero-pressure geometry generated using micro-computed tomography. Residual stress was determined from the aTAA opening angle. aTAA material properties determined using biaxial stretch testing were incorporated into an Ogden hyperelastic model. Finite element analyses (FEAs) were performed in LS-DYNA to determine wall stress distribution and magnitudes at systemic pressure. RESULTS: The left aTAA region had the highest stiffness, followed by the right, and then anterior/posterior walls, suggesting regional variability in mechanical properties. During systole, the mean principal wall stresses were 108.8 kPa (circumferential) and 59.9 kPa (longitudinal), while peak wall stresses were 789.4 kPa (circumferential) and 618.8 kPa (longitudinal). Elevated wall stress pockets were seen in anatomic left aTAA regions. CONCLUSIONS: To the present authors' knowledge, this was the first patient-specific BAV aTAA model based on surgical specimens to be developed. Surgical specimens serve as the 'gold standard' for determining wall stress to validate models based on in-vivo imaging data alone. Regions of maximal wall stress may indicate sites most prone to rupture, and are crucial for evaluating rupture risk based on the wall stress/strength relationship.

Contextual effects on perceived contrast: figure-ground assignment and orientation contrast.

Figure-ground segregation is an important step in the path leading to object recognition. The visual system segregates objects ('figures') in the visual scene from their backgrounds ('ground'). Electrophysiological studies in awake-behaving monkeys have demonstrated that neurons in early visual areas increase their firing rate when responding to a figure compared to responding to the background. We hypothesized that similar changes in neural firing would take place in early visual areas of the human visual system, leading to changes in the perception of low-level visual features. In this study, we investigated whether contrast perception is affected by figure-ground assignment using stimuli similar to those in the electrophysiological studies in monkeys. We measured contrast discrimination thresholds and perceived contrast for Gabor probes placed on figures or the background and found that the perceived contrast of the probe was increased when it was placed on a figure. Furthermore, we tested how this effect compared with the well-known effect of orientation contrast on perceived contrast. We found that figure-ground assignment and orientation contrast produced changes in perceived contrast of a similar magnitude, and that they interacted. Our results demonstrate that figure-ground assignment influences perceived contrast, consistent with an effect of figure-ground assignment on activity in early visual areas of the human visual system.

Human pulmonary autograft wall stress at systemic pressures prior to remodeling after the Ross procedure.

BACKGROUND AND AIM OF THE STUDY: Remodeling of the pulmonary autograft upon exposure to systemic pressure can lead to progressive dilatation and aneurysmal pathology. Remodeling is driven by changes in autograft wall stress upon exposure to systemic pressure; however, the magnitude of these changes is unknown. Previously, a porcine autograft finite element model was developed to determine wall stress, but the porcine and human material properties differed significantly. Hence, the study aim was to understand human pulmonary autograft biomechanics that lead to remodeling by determining wall stress magnitudes immediately after the Ross procedure using finite element analysis (FEA). METHODS: Human pulmonary root was scanned by high-resolution microcomputed tomography to construct a realistic three-dimensional geometric mesh. Stress-strain data from biaxial stretch testing was incorporated into an Ogden hyperelastic model to describe autograft mechanical properties for an adult Ross patient. Autograft dilatation and wall stress distribution during pulmonic and systemic pressures prior to remodeling were determined using explicit FEA in LS-DYNA. RESULTS: Human pulmonary autograft demonstrated non-linear material properties, being highly compliant in the low-strain region, and stiffening at high strain. The majority of dilatation occurred with < 20 mmHg pressurization. From pulmonary to systemic pressures, the increases in autograft diameter were up to 17%. Likewise, the maximal wall stress increased approximately 14.6-fold compared to diastolic pressures (from 13.0 to 190.1kPa), and six-fold compared to systolic pressures (from 48.6 to 289.6kPa). CONCLUSION: The first finite element model of the human pulmonary autograft was developed and used to demonstrate how autograft material properties prevent significant dilatation upon initial exposure to systemic pressure. Mild dilatation was noted in the sinuses and sinotubular junction. Autograft wall stress was increased greatly when subjected to systemic pressures, and may trigger biomechanical remodeling of the autograft. Sustained exposure to higher wall stresses, coupled with inadequate remodeling, may lead to future autograft dilatation.

Patient-specific finite element analysis of ascending thoracic aortic aneurysm.

BACKGROUND AND AIM OF THE STUDY: Rupture/dissection of ascending thoracic aortic aneurysm (aTAA) is a cardiovascular emergency. Elective surgical repair is primarily based on maximum diameter, but complications have occurred under the size limits for surgical intervention. aTAA wall stress may be a better predictor of patient-specific rupture risk, but cannot be directly measured in vivo. The study aim was to develop an aTAA computational model associated with tricuspid aortic valve (TAV) to determine patient-specific wall stresses. METHODS: A TAV-associated aTAA was excised intact during surgery. Zero-pressure geometry was generated from microcomputed tomography, and an opening angle was used to calculate residual stress. Material properties determined from stress-strain data were incorporated into an Ogden hyperelastic model. Wall stress distribution and magnitudes at systemic pressure were determined using finite element analyses (FEA) in LS-DYNA. RESULTS: Regional material property differences were noted: the left aTAA region had a higher stiffness compared to the right, and anterior/posterior walls. During systole, the mean principal wall stresses were 172.0 kPa (circumferential) and 71.9 kPa (longitudinal), while peak wall stresses were 545.1 kPa (circumferential) and 430.1 kPa (longitudinal). Elevated wall stress pockets were seen in anatomic left and right aTAA regions. CONCLUSION: A validated computational approach was demonstrated to determine aTAA wall stresses in a patient-specific fashion, taking into account the required zero-stress geometry, wall thickness, material properties and residual stress. Regions of maximal wall stress may indicate the sites most prone to rupture. The creation of a patient-specific aTAA model based on a surgical specimen is necessary to serve as the 'gold standard' for comparing models based on in-vivo data alone. Validated data using the surgical specimen are essential for establishing wall stress and rupture-risk relationships.

Definitions of Histological Abnormalities in Inflammatory Bowel Disease: an ECCO Position Paper.

Histological assessment of endoscopic biopsies in inflammatory bowel disease [IBD] plays an important role in clinical management, investigative studies, and clinical trials. Scoring schemes consisting of multiple histological items and offering considerable precision are widely available. However, definitions of histological abnormalities are often inconsistent. Furthermore, interobserver variability for their recognition and assessment may be high. The European Crohn's and Colitis Organisation [ECCO] formed an expert panel to explore definitions of histological abnormalities in IBD, with the aim of improving the quality of diagnosis and facilitating development of scoring schemes. The process confirmed that the current definitions often have no evidence base and vary between sources. Using available evidence and expert knowledge, the panel produced a series of ECCO consensus position statements on histological features in IBD.

Histological Outcomes And Jak-Stat Signalling In Ulcerative Colitis Patients Treated With Tofacitinib.

BACKGROUND AND AIMS: Histological outcomes and JAK-STAT signaling were assessed in a prospective ulcerative colitis (UC) patient cohort after 8 weeks treatment with tofacitinib, an oral Janus kinase (JAK) inhibitor. METHODS: Forty UC patients received tofacitinib 10 mg twice daily for 8 weeks. Treatment response was defined as histo-endoscopic mucosal improvement (HEMI). Histological remission was defined as a Robarts Histopathology Index (RHI) ≤3 points and histological response as 50% decrease in RHI. Mucosal expression of JAK1-3, Tyrosine kinase 2 (TYK2) and total signal transducer and activator of transcription (STAT) 1-6 were assessed using immunohistochemistry (IHC). RESULTS: At baseline, the median RHI was 14 (interquartile range (IQR) 10-19). Twenty-six of 40 (65%) patients had severe endoscopic disease (endoscopic Mayo score 3) and 31/40 (78%) failed prior anti-TNF treatment. At week 8, 15 patients (38%) had HEMI, 23 patients (58%) histological remission and 34 (85%) histological response. RHI decreased by a median of 14 points (IQR 9-21) in responders (p<0.001) and by 6 points (IQR 0-13) in non-responders (p=0.002). STAT1, STAT3 and STAT5 expression levels decreased significantly in the whole cohort. Responders had lower week 8 STAT1 expression levels compared to non-responders (0.2%, IQR 0.1-2.8 vs 4.3%, IQR 1.2-11.9, p=0.001), suggesting more profound STAT1 blockade. A trend of higher baseline JAK2 expression was observed in tofacitinib non-responders (2.7%, IQR 0.1-7.7) compared to responders (0.4%, IQR 0.1-2.1). CONCLUSIONS: Tofacitinib treatment resulted in histological improvement in the majority of UC patients and a substantial decrease of STAT1, STAT3 and STAT5 expression. HEMI was associated with more profound suppression of STAT1.

Prognostic Value of Colonic Tissue and Blood Eosinophils in Ulcerative Colitis.

BACKGROUND: It has been suggested that eosinophils may be a prognostic marker of disease outcome in ulcerative colitis (UC), but conflicting data exist. The objective was to investigate the extent of mucosal eosinophils and peripheral blood eosinophil count in newly diagnosed UC patients and to investigate its predictive value in short- and long-term disease outcomes. METHODS: The degree of eosinophilia in baseline colonic biopsies and blood of newly diagnosed UC patients was retrospectively analyzed. It was investigated if tissue and blood eosinophilia could be a marker of a severe phenotype of UC, defined as the need for corticosteroids or immunomodulators in the first year or treatment with therapeutic monoclonal antibodies or colectomy during follow-up. Time to therapeutic monoclonal antibodies and time to colectomy were also evaluated as outcomes. RESULTS: There were 103 UC patients (median age 26 years) included. Median tissue peak eosinophil count (PEC) was 70.0 and median peripheral blood eosinophil count was 0.3 × 109/L at diagnosis. Tissue PEC (r = -0.161, P = .104) and blood eosinophil count (r = 0.022, P = .877) were not correlated with the severity of histologic inflammation. Logistic regression analyses did not identify PEC and blood eosinophil count as predictors of more severe disease outcomes. Tissue PEC and peripheral blood eosinophil count did not predict the time the initiation of therapeutic monoclonal antibodies or colectomy. CONCLUSION: Baseline tissue or peripheral blood eosinophils are not markers of disease activity and cannot be used as a predictor of severe disease outcomes in both adults and children with UC.

Baseline tissue or peripheral blood eosinophils are not markers of disease activity and cannot be used as a predictor of severe disease outcomes in both adults and children with ulcerative colitis.

Temperature-triggered in situ forming lipid mesophase gel for local treatment of ulcerative colitis.

Ulcerative colitis is a chronic inflammatory bowel disease that strongly affects patient quality of life. Side effects of current therapies necessitate new treatment strategies that maximise the drug concentration at the site of inflammation, while minimizing systemic exposure. Capitalizing on the biocompatible and biodegradable structure of lipid mesophases, we present a temperature-triggered in situ forming lipid gel for topical treatment of colitis. We show that the gel is versatile and can host and release drugs of different polarities, including tofacitinib and tacrolimus, in a sustained manner. Further, we demonstrate its adherence to the colonic wall for at least 6 h, thus preventing leakage and improving drug bioavailability. Importantly, we find that loading known colitis treatment drugs into the temperature-triggered gel improves animal health in two mouse models of acute colitis. Overall, our temperature-triggered gel may prove beneficial in ameliorating colitis and decreasing adverse effects associated with systemic application of immunosuppressive treatments.

The clinical relevance of an inflamed appendix in Crohn's disease.

BACKGROUND AND AIMS: An appendectomy for appendiceal inflammation has been suggested to ameliorate the clinical course of patients with ulcerative colitis (UC). In contrast, for Crohn's disease (CD) an inverse association has been suggested with a higher incidence of CD and worse prognosis after appendectomy. The aim of this study was to analyse the clinical relevance of an inflamed appendix in CD patients undergoing ileocoecal resection (ICR). METHODS: All consecutive patients undergoing primary ICR between 2007 and 2018 were considered for inclusion. Microscopic data of available appendiceal resection specimens (n=99) were revised by a dedicated IBD-pathologist and scored as inflamed or not inflamed. Eighteen patients had a previous appendectomy. Pathological findings were correlated with disease characteristics and recurrence rates (clinical, endoscopic and intervention-related). RESULTS: In total, 117 patients were included: 77 (65.8%) females with a median age of 30 years [IQR 24 - 43] with a median follow up of 102 months [IQR 76-114]. Of patients without previous appendectomy (n=99), 39% had an inflamed appendix. No significant differences in disease characteristics (e.g. disease location, behaviour, time to surgery) or prognosis could be demonstrated between the two groups. In contrast, previous appendectomy (n=18) was associated with penetrating disease and numerically shorter disease duration at the time of resection. Furthermore, a trend was seen towards a stronger association with postoperative recurrence. CONCLUSION: The current study could not confirm a different prognosis for CD patients with and without an inflamed appendix. In contrast, in patients with a previous appendectomy a trend was seen towards increased postoperative recurrence, which might be related to the higher incidence of penetrating disease.

Mercaptopurine for the Treatment of Ulcerative Colitis: A Randomized Placebo-Controlled Trial.

BACKGROUND AND AIMS: Scepticism about the efficacy of thiopurines for ulcerative colitis [UC] is rising. This study aimed to evaluate mercaptopurine treatment for UC. METHODS: In this prospective, randomized, double-blind, placebo-controlled trial, patients with active UC, despite treatment with 5-aminosalicylates [5-ASA], were randomized for therapeutic drug monitoring [TDM]-guided mercaptopurine treatment or placebo for 52 weeks. Corticosteroids were given in the first 8 weeks and 5-ASA was continued. Proactive metabolite-based mercaptopurine and placebo dose adjustments were applied from week 6 onwards by unblinded clinicians. The primary endpoint was corticosteroid-free clinical remission and endoscopic improvement [total Mayo score ≤2 points and no item >1] at week 52 in an intention-to-treat analysis. RESULTS: Between December 2016 and April 2021, 70 patients were screened and 59 were randomized at six centres. In the mercaptopurine group, 16/29 [55.2%] patients completed the 52-week study, compared to 13/30 [43.3%] on placebo. The primary endpoint was achieved by 14/29 [48.3%] patients on mercaptopurine and 3/30 [10%] receiving placebo (Δ = 38.3%, 95% confidence interval [CI] 17.1-59.4, p = 0.002). Adverse events occurred more frequently with mercaptopurine [808.8 per 100 patient-years] compared to placebo [501.4 per 100 patient-years]. Five serious adverse events occurred, four on mercaptopurine and one on placebo. TDM-based dose adjustments were executed in 22/29 [75.9%] patients, leading to lower mercaptopurine doses at week 52 compared to baseline. CONCLUSIONS: Optimized mercaptopurine treatment was superior to placebo in achieving clinical, endoscopic and histological outcomes at 1 year following corticosteroid induction treatment in UC patients. More adverse events occurred in the mercaptopurine group.

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.

Clinical relevance of endoscopic peri-appendiceal red patch in ulcerative colitis patients.

Background: Increasing evidence is suggesting appendectomy as an alternative treatment for ulcerative colitis (UC), especially in case of histological appendiceal inflammation. Therefore, preoperative identification of appendiceal inflammation could be beneficial. This study aimed to assess the prevalence of peri-appendiceal red patch (PARP) on colonoscopy. In addition, prognostic relevance of PARP for disease course and its predictive value for histological appendiceal inflammation in patients undergoing appendectomy was assessed. Methods: UC patients undergoing colonoscopy in 2014/2015 were included to determine PARP-prevalence in a cross-sectional study. Findings were correlated to patient and disease characteristics, upscaling of treatment and colectomy rates after cross-sectional colonoscopy. In patients undergoing appendiceal resection, histopathological inflammation was assessed using the Robarts Histopathology Index (RHI). Results: In total, 249 patients were included of which 17.7% (44/249) had a PARP. Patients with PARP were significantly younger with a shorter disease course. The majority of patients with PARP (61.4%) was in endoscopic remission. Patients with PARP required more upscaling of medical therapy (81.8% vs. 58.0%, p < 0.01), and more PARP patients underwent colectomy (13.6% vs. 4.9%, p = 0.04). Patients with PARP had a higher median RHI in resection specimens (14 vs. 7, p < 0.01). Conclusion: PARP was present during colonoscopy regardless disease activity and was predominantly found in UC patients with younger age and shorter disease duration. PARP patients had a more severe course of UC, and in case of appendectomy, more severe histopathological appendiceal inflammation. Appendectomy as an experimental therapy for UC has been suggested to be predominantly effective in UC patients with appendiceal inflammation. This study demonstrates that presence of a PARP on colonoscopy predicts appendiceal inflammation. After consensus has been reached on the therapeutic effect of appendectomy, assessing PARP presence during colonoscopy could therefore contribute to identifying patients most likely to respond.