The gut-brain axis: Correlation of choroid plexus volume and permeability with inflammatory biomarkers in Crohn's disease.

BACKGROUND: The dysregulation of the gut-brain axis in chronic inflammatory bowel diseases can cause neuro-psychological disturbances, but the underlying mechanisms are still not fully understood. The choroid plexus (CP) maintains brain homeostasis and nourishment through the secretion and clearance of cerebrospinal fluid. Recent research has demonstrated the existence of a CP vascular barrier in mice which is modulated during intestinal inflammation. This study investigates possible correlations between CP modifications and inflammatory activity in patients with Crohn's disease (CD). METHODS: In this prospective study, 17 patients with CD underwent concomitant abdominal and brain 3 T MRI. The volume and permeability of CP were compared with levels of C-reactive protein (CRP), fecal calprotectin (FC), sMARIA and SES-CD scores. RESULTS: The CP volume was negatively correlated with CRP levels (R = -0.643, p-value = 0.024) and FC (R = -0.571, p-value = 0.050). DCE metrics normalized by CP volume were positively correlated with CRP (K-trans: R = 0.587, p-value = 0.045; Vp: R = 0.706, p-value = 0.010; T1: R = 0.699, p-value = 0.011), and FC (Vp: R = 0.606, p-value = 0.037). CONCLUSIONS: Inflammatory activity in patients with CD is associated with changes in CP volume and permeability, thus supporting the hypothesis that intestinal inflammation could affect the brain through the modulation of CP vascular barrier also in humans.

An international multicentre study of SwiTching from Intravenous to subcutaneous inflixiMab and vEdolizumab in inflammatory bowel diseases: The TIME study.

BACKGROUND AND AIMS: Subcutaneous (SC) formulations of infliximab (IFX) and vedolizumab (VDZ) are approved for the treatment of inflammatory bowel diseases (IBDs). Our aim was to evaluate the effectiveness of switching from intravenous (IV) to SC formulations of IFX and VDZ in IBDs. METHODS: This multicentre, retrospective study collected data of adult patients with Crohn's disease (CD) or ulcerative colitis (UC) switched to SC IFX or VDZ. The primary endpoint was clinical remission at 12 months stratified based on timing of switch. A composite endpoint consisting of therapy discontinuation, reverse-switch, need for steroids, and drug optimization was evaluated. A multivariate analysis investigated the association between patients' characteristics and outcomes. RESULTS: Two hundred and thirty-one patients (59% UC, 53% male, mean age 44 ± 15 years, 68% IFX) from 13 centres were included. The switch occurred at Week 6 in a third of cases (36%). Median time to switch was 13 months. Most patients switched to SC IFX and VDZ were in clinical remission at 3 (87% and 77%), 6 (86% and 83%) and 12 (63% and 60%) months. In the multivariate analysis, there was no difference in clinical remission rate at 12 months; however, patients switched at Week 6 had a higher rate of experiencing any therapeutic changes at 3 (false discovery rate (FDR) = .002), 6 (FDR <1 × 10-10) or 12 months (FDR = .08). Clinical disease activity at baseline (only in UC) (FDR = .07) and previous exposure to biologics (FDR = .001) were risk factors for composite endpoint at 6 and 12 months. CONCLUSION: SC IFX and VDZ are effective in daily clinical practice in IBD patients. Switching patients in remission reduces the risk of negative outcomes.

Gut virome-colonising Orthohepadnavirus genus is associated with ulcerative colitis pathogenesis and induces intestinal inflammation in vivo.

OBJECTIVES: Ulcerative colitis (UC) is a chronic inflammatory disorder of unknown aetiology. Gut virome dysbiosis is fundamental in UC progression, although its role in the early phases of the disease is far from fully understood. Therefore, we sought to investigate the role of a virome-associated protein encoded by the Orthohepadnavirus genus, the hepatitis B virus X protein (HBx), in UC aetiopathogenesis. DESIGN: HBx positivity of UC patient-derived blood and gut mucosa was assessed by RT-PCR and Sanger sequencing and correlated with clinical characteristics by multivariate analysis. Transcriptomics was performed on HBx-overexpressing endoscopic biopsies from healthy donors.C57BL/6 mice underwent intramucosal injections of liposome-conjugated HBx-encoding plasmids or the control, with or without antibiotic treatment. Multidimensional flow cytometry analysis was performed on colonic samples from HBx-treated and control animals. Transepithelial electrical resistance measurement, proliferation assay, chromatin immunoprecipitation assay with sequencing and RNA-sequencing were performed on in vitro models of the gut barrier. HBx-silencing experiments were performed in vitro and in vivo. RESULTS: HBx was detected in about 45% of patients with UC and found to induce colonic inflammation in mice, while its silencing reverted the colitis phenotype in vivo. HBx acted as a transcriptional regulator in epithelial cells, provoking barrier leakage and altering both innate and adaptive mucosal immunity ex vivo and in vivo. CONCLUSION: This study described HBx as a contributor to the UC pathogenesis and provides a new perspective on the virome as a target for tailored treatments.

Noninvasive Assessment of Postoperative Disease Recurrence in Crohn's Disease: A Multicenter, Prospective Cohort Study on Behalf of the Italian Group for Inflammatory Bowel Disease.

BACKGROUND & AIMS: Colonoscopy (CS) is the gold standard to assess postoperative recurrence (POR) in Crohn's disease (CD). However, CS is invasive and may be poorly tolerated by patients. The aim of this study was to prospectively assess the diagnostic accuracy of a noninvasive approach in detecting POR, using the endoscopic Rutgeerts' score (RS) as the reference standard. METHODS: Consecutive patients with CD who underwent ileo-cecal resection were prospectively enrolled in 3 referral Italian centers. Patients underwent CS and bowel ultrasound within 1 year of surgery. Uni- and multivariable analyses were used to assess the correlation between noninvasive parameters and endoscopic recurrence, defined by a RS ≥2. RESULTS: Ninety-one patients were enrolled. Sixty patients (66%) experienced endoscopic POR. The multivariable analysis identified bowel wall thickness (BWT) per 1-mm increase (odds ratio [OR], 2.43; 95% confidence interval [CI], 1.21-4.89; P = .012), the presence of mesenteric lymph nodes (OR, 15.63; 95% CI, 1.48-164.54; P = .022), and fecal calprotectin (FC) values ≥50 mcg/g (OR, 8.58; 95% CI, 2.45-29.99; P < .001) as independent predictors for endoscopic recurrence. The presence of lymph nodes or the combination of BWT ≥3 mm and FC values ≥50 mcg/g correctly classified 56% and 75% of patients, with less than 5% of patients falsely classified as having endoscopic recurrence. Conversely, the combination of BWT <3 mm and FC <50 mcg/g correctly classified 74% of patients with only 4.5% of patients falsely classified as not having endoscopic recurrence. CONCLUSIONS: A noninvasive approach combining bowel ultrasound and FC can be used with confidence for detecting POR in patients with CD without the requirement for CS.

Predictive Value of Bowel Ultrasound in Crohn's Disease: A 12-Month Prospective Study.

BACKGROUND & AIMS: Mucosal healing is associated with better outcomes in Crohn's disease (CD). Colonoscopy is invasive and poorly tolerated. Bowel ultrasound (US) is a noninvasive tool that increasingly is being used for CD assessment. We assessed the predictive role of baseline bowel US findings on disease course in a large prospective cohort of CD patients for 12 months. METHODS: Ileocolonic CD consecutive patients were followed up for 12 months after performing bowel US. The negative course of CD, defined as the need for steroids and/or change of therapy and/or hospitalization and/or the need for surgery, was assessed. We evaluated this composite end point and subsequently considered each individual end point separately. Predictors of negative disease course were analyzed by logistic regression analysis. RESULTS: There were 225 ileal and/or colonic CD consecutive patients included in the study. We analyzed the association between baseline bowel US parameters and endoscopic activity (defined as a Simplified Endoscopic Activity score for CD > 2) to set up a noninvasive quantitative ultrasound-based score (bowel ultrasound score). The multivariable analysis identified the following independent predictors of a worse outcome throughout the 12-month period as follows: bowel ultrasound score greater than 3.52 (odds ratio [OR], 6.97; 95% CI, 2.87-16.93; P < .001), presence of at least 1 disease complication (stricture, fistula, abscess) at baseline bowel US (OR, 3.90; 95% CI, 1.21-12.53; P = .021), fecal calprotectin value of 250 µg/g or greater at baseline (OR, 5.43; 95% CI, 2.25-13.11; P < .001), and male sex (OR, 2.60; 95% CI, 1.12-6.02; P = .025). CONCLUSIONS: Bowel US predicts the 12-month course in CD.

Reproducibility of the electronic chromoendoscopy PICaSSO score (Paddington International Virtual ChromoendoScopy ScOre) in ulcerative colitis using multiple endoscopic platforms: a prospective multicenter international study (with video).

BACKGROUND AND AIMS: Endoscopic and histologic remission (HR) are key therapeutic targets in the management of ulcerative colitis (UC). The aim of this study was to evaluate the reproducibility of the Paddington International virtual ChromoendoScopy ScOre (PICaSSO), a virtual chromoendoscopy score originally validated by use of the iSCAN platform, with the narrow-band imaging (NBI), linked-color imaging (LCI), and blue-laser imaging (BLI) platforms. METHODS: We evaluated endoscopic activity using the Mayo Endoscopic Score (MES), the Ulcerative Colitis Endoscopic Index of Severity (UCEIS), and PICaSSO in 159 UC patients (78 NBI and 81 BLI/LCI) who underwent colonoscopy in 2 tertiary referral centers. HR was defined by the Robarts Histopathology Index (RHI) and the Nancy Histologic Index (NHI). Receiver operating characteristic curves were plotted to evaluate endoscopic scores for the prediction of HR. Intraclass correlation coefficients (ICC) between endoscopists were evaluated. RESULTS: PICaSSO had an ICC of 0.825 when the NBI and BLI/LCI cohorts were combined, higher than MES and UCEIS. The correlation between PICaSSO and RHI and NHI was 0.83 and 0.79 in the NBI cohort and between 0.63 and 0.65 in LCI/BLI. In the NBI cohort, the accuracy of MES, UCEIS, and PICaSSO was 0.936, 0.897, and 0.808 for HR measured by RHI and 0.897, 0.885, and 0.821 by NHI, respectively. In the BLI/LCI cohort, the accuracy of MES, UCEIS, LCI PICaSSO and BLI PICaSSO was 0.765, 0.778, 0.827, and 0.79 to predict HR with RHI and NHI, respectively. CONCLUSIONS: The PICaSSO score can be consistently and accurately reproduced with NBI and LCI/BLI and therefore can be applied to all virtual electronic chromoendoscopy platforms.

Incidence and Patterns of COVID-19 Among Inflammatory Bowel Disease Patients From the Nancy and Milan Cohorts.

The first cases of COVID-19 infection were reported in December, 2019, in Wuhan, China. Italy (in particular Lombardy) and France (in particular Northeast) have been gravely hit. Both physicians and inflammatory bowel disease (IBD) patients are deeply concerned that immunosuppressants or biologics may increase the risk of COVID-19 infection. IOIBD has put in place an international registry, SECURE-IBD, for tracking all the cases with IBDs infected by COVID-19 (SECURE-IBD registry: http://www.covidibd.org). It will describe the outcomes of infected patients and the association between IBD-related medications and these outcomes.

Maintaining the Quality Standards of Care for Inflammatory Bowel Disease Patients During the COVID-19 Pandemic.

Since February 20, 2020, the SARS-COV2 infection has spread in Lombardy, and in the rest of the Italian regions, forcing our government to impose a national lockdown.1 Hospitals have been forced to adapt and to restructure their units to cope with this urgent new critical situation.2 Alternative solutions have been found to manage patients with inflammatory bowel disease (IBD), including remote monitoring, drug home delivery, limitations for infusion units, and patient education on measures to prevent infection,3 to maintain high-quality care.4.

Absence of COVID-19 Infection in Patients Accessing IBD Unit at Humanitas, Milan: Implications for Postlockdown Measures.

INTRODUCTION: The risk of coronavirus disease-19 infection for healthcare professionals and patients in hospitals remains unclear. METHODS: We investigated whether precautions adopted in our inflammatory bowel disease (IBD) unit have minimized the risks of infection for all patients accessing our facilities in a 1-month period by assessing the rate of coronavirus disease-19 infection in the follow-up period. RESULTS: Three hundred-twenty patients with IBD were included. None were infected from severe acute respiratory syndrome-coronavirus 2 in the follow-up period. None of the IBD team members were infected. DISCUSSION: Neither pharmacological immunosuppression nor access to the hospital seem to be risk factors for infection in patients with IBD.

Advanced endoscopic techniques in the assessment of inflammatory bowel disease: new technology, new era.

Endoscopic assessment of inflammation and mucosal healing is crucial for appropriate management in IBD. Current definition of endoscopic mucosal healing has been derived using previous generation of standard white light endoscopes. New endoscopy technologies widely available provide much more detailed images of mucosal and vascular patterns. Novel endoscopic techniques with high definition image, optical and digital enhancement have enhanced the quality and fine details of vascular and mucosal pattern so that endoscopic images have started to reflect histological changes for lesions and inflammation/healing. These technologies can now define subtle inflammatory changes and increase detection and characterisation of colonic lesions in patients with IBD. The best endoscopic technique to detect dysplasia in IBD is still debated. Dye chromoendoscopy with targeted biopsies is considered by Surveillance for Colorectal Endoscopic Neoplasia Detection and Management in inflammatory Bowel Disease Patients: International Consensus Recommendations (SCENIC consensus the standard of care and recommended for adoption by gastroenterologists in practice. In future, it is possible that well-trained colonoscopists using high definition equipment with image enhancements may be able to obtain equivalent yield without pan-colonic dye spraying and characterise lesions. Finally, SCENIC introduced endoscopic resectability of some dysplastic colonic lesions-new techniques may now better characterise endoscopic resectability and limit the number of colectomies. In this review, we will provide a state-of-the-art opinion on the direction of technological advances in the assessment of IBD and how new concepts will refine clinical practice.

MFSD2A Promotes Endothelial Generation of Inflammation-Resolving Lipid Mediators and Reduces Colitis in Mice.

BACKGROUND & AIMS: Alterations in signaling pathways that regulate resolution of inflammation (resolving pathways) contribute to pathogenesis of ulcerative colitis (UC). The resolution process is regulated by lipid mediators, such as those derived from the ω-3 docosahexaenoic acid (DHA), whose esterified form is transported by the major facilitator superfamily domain containing 2A (MFSD2A) through the endothelium of brain, retina, and placenta. We investigated if and how MFSD2A regulates lipid metabolism of gut endothelial cells to promote resolution of intestinal inflammation. METHODS: We performed lipidomic and functional analyses of MFSD2A in mucosal biopsies and primary human intestinal microvascular endothelial cells (HIMECs) isolated from surgical specimens from patients with active, resolving UC and healthy individuals without UC (controls). MFSD2A was knocked down in HIMECs with small hairpin RNAs or overexpressed from a lentiviral vector. Human circulating endothelial progenitor cells that overexpress MFSD2A were transferred to CD1 nude mice with dextran sodium sulfate-induced colitis, with or without oral administration of DHA. RESULTS: Colonic biopsies from patients with UC had reduced levels of inflammation-resolving DHA-derived epoxy metabolites compared to healthy colon tissues or tissues with resolution of inflammation. Production of these metabolites by HIMECs required MFSD2A, which is required for DHA retention and metabolism in the gut vasculature. In mice with colitis, transplanted endothelial progenitor cells that overexpressed MFSD2A not only localized to the inflamed mucosa but also restored the ability of the endothelium to resolve intestinal inflammation, compared with mice with colitis that did not receive MFSD2A-overexpressing endothelial progenitors. CONCLUSIONS: Levels of DHA-derived epoxides are lower in colon tissues from patients with UC than healthy and resolving mucosa. Production of these metabolites by gut endothelium requires MFSD2A; endothelial progenitor cells that overexpress MFSD2A reduce colitis in mice. This pathway might be induced to resolve intestinal inflammation in patients with colitis.

Intestinal gas and liver steatosis: a casual association? A prospective multicentre assessment.

BACKGROUND & AIMS: Excessive intestinal gas and liver steatosis are frequent sonographic findings. Both of these appear to be caused by variations of the gut microflora. We assessed the relationship between ultrasonographic detection of intestinal gas and liver steatosis. METHODS: This study included 204 consecutive patients (99 male; mean age 53.0 ± 15.6 years), who underwent ultrasonography for abdominal complaints or follow-up of benign lesions. Body mass index, biochemical liver markers, sonographic presence of liver steatosis and/or degree of intestinal gas interfering with the examination were collected. Both sonographic findings were assessed based on standardized criteria. The association between liver steatosis and intestinal gas was evaluated by means of univariate and multivariate analyses. RESULTS: Eighty (39.2%) of patients showed moderate to large amounts of gas preventing an accurate evaluation of the liver or pancreas and 90 (44.1%) had liver steatosis. A significant correlation between the degree of intestinal gas and liver steatosis both in obese (r=.603; P<.001) and in nonobese patients (r=.555; P<.001) was found. Univariate analysis showed that intestinal gas, body mass index, aspartate transaminase, alanine transaminase, gamma-GT, age and sex were predictors of liver steatosis; only intestinal gas (OR 7.4; 95% CI 3.4-16.1) and body mass index (OR; 1.4, 95% CI 1.2-1.5), however, were independent predictors at multivariate analysis. The presence of excessive gas was also significantly correlated with liver steatosis coupled with elevated ALT (P = .001). CONCLUSION: This study shows a significant correlation between excessive intestinal gas and liver steatosis. The reasons of this finding and its clinical implications remain to be defined.

Effectiveness of Mesalazine, Thiopurines and Tumour Necrosis Factor Antagonists in Preventing Post-Operative Crohn's Disease Recurrence in a Real-Life Setting.

BACKGROUND: Most Crohn's disease (CD) patients develop endoscopic recurrence within one year of intestinal resection. The best treatment method to prevent post-operative CD recurrence remains uncertain. METHODS: A total of 155 CD patients from 2 referral centres, who were undergoing intestinal resection with ileo-colonic anastomosis (January 2004-January 2015), were included. All subjects received preventive therapy with tumour necrosis factor antagonists (anti-TNFs), thiopurinesor mesalazine. The primary outcome was the rate of endoscopic recurrence (Rutgeerts score ≥i2) in the 3 treatment groups. RESULTS: Patients treated with anti-TNFs were at significantly lower risk of endoscopic recurrence during the follow-up than those receiving thiopurines or mesalazine (incidence rates of 2.2, 3.0 and 4.8 per 100 person-months, respectively, log-rank, p = 0.011). The median time to recurrence was significantly longer in patients treated with anti-TNFs than in those who received thiopurines or mesalazine (37.0, 13.7, and 16.8 months, respectively, log-rank, p = 0.011). Anti-TNFs were more effective than mesalazine (univariable analysis, hazard ratio [HR] 0.45, 95% CI 0.26-0.77, p = 0.004; multivariable analysis, HR 0.45, 95% CI 0.26-0.77, p = 0.004), and non-significantly superior over thiopurines. CONCLUSION: Anti-TNF therapy was the most effective strategy for the prevention of endoscopic CD recurrence.

Discontinuation of Infliximab in Patients With Ulcerative Colitis Is Associated With Increased Risk of Relapse: A Multinational Retrospective Cohort Study.

BACKGROUND & AIMS: Infliximab is a safe and effective therapy for ulcerative colitis (UC). We conducted a multicenter retrospective cohort study that included 7 European countries and Israel to examine whether infliximab discontinuation can be considered for patients who achieve sustained remission. METHODS: We performed a retrospective cohort study, collecting medical records from 13 tertiary care referral inflammatory bowel disease centers of all patients with UC treated with infliximab (n = 193). We compared the disease course of patients with at least 12 months of clinical remission who discontinued infliximab (n = 111) with that of patients who continued scheduled treatment (controls, n = 82). We examined the incidence rates of relapse, hospitalization and colectomy, the comparative effectiveness of different therapeutic strategies after discontinuation, and assessed the rates of response, remission, and adverse effects after infliximab re-initiation. Statistical analyses used time-to-event methods. RESULTS: In the entire cohort, 67 patients (34.7%) relapsed during the follow-up period. The incidence rate of relapse was significantly higher after discontinuation (23.3 per 100 person-years) compared with the control group (7.2 per 100 person-years) in univariable analysis (log-rank P < .001; hazard ratio, 3.41; 95% confidence interval, 1.88-6.20) and multivariable analysis (hazard ratio, 3.70; 95% confidence interval, 2.02-6.77). Rates of hospitalization and colectomy did not differ between groups. Thiopurines appeared to be the best treatment option after infliximab discontinuation (incidence of relapse: 15.0 per 100 person-years for thiopurines, 27.4 per 100 person-years for thiopurines plus aminosalicylates, and 31.2 per 100 person-years for aminosalicylates alone; log-rank P = .032). Response was regained in 77.1% of patients and remission in 51.4% of patients who re-initiated infliximab. However, 17.1% had infusion reactions and 17.1% reported other adverse events. CONCLUSIONS: In a multinational retrospective cohort study of patients with UC in sustained clinical remission, we associated discontinuation of infliximab with an increased risk of relapse. Treatment re-initiation is effective and safe.

Perianal disease is associated with psychiatric co-morbidity in Crohn's disease in remission.

BACKGROUND AND AIM: Crohn's disease is a life-long inflammatory disease which can impair quality of life, in particular in patients with psychiatric co-morbidities such as depression and anxiety. The aim of this prospective cohort study was to assess the prevalence of depression and anxiety and related risk factors in patients with quiescent Crohn's disease. METHODS: A consecutive series of adult patients with confirmed diagnosis of Crohn's disease, in clinical remission, were included and investigated during ambulatory visits using a standard questionnaire assessing demographic and clinical features of the disease. Within 1 month after the ambulatory visit, all patients were interviewed by phone to assess the presence of psychiatric disorders using standardized questionnaires. The questionnaire assessed the development of psychiatric disorders after the diagnosis of Crohn's disease, the use of antidepressant or antianxiety therapy and current anxiety or depression by means of the Hospital Anxiety and Depression Scale. RESULTS: One hundred and ninety-five patients were included. Seventy-two (36.9 %) patients showed anxiety and/or depression symptoms, 46 (23.6 %) patients showed anxiety symptoms, 6 (3.1 %) patients showed depression symptoms and 20 (10.3 %) patients showed both symptoms. Forty-eight of these patients (58 %) were without any antidepressive or antianxiety treatment. Anxiety with or without depression was significantly correlated with female sex (p = 0.017), history of perianal disease (p = 0.003) and perianal surgery (p = 0.042). CONCLUSION: Anxiety is a frequent, often untreated, condition in patient affected by Crohn's disease in clinical remission. Female sex, history of perianal disease and perianal surgery are major risk factors for anxiety.

Immunity in digestive diseases: new drugs for inflammatory bowel disease treatment-insights from Phase II and III trials.

BACKGROUND: Inflammatory bowel disease (IBD), encompassing Crohn's disease (CD) and ulcerative colitis (UC), continues to challenge treatment paradigms. Advancements in therapeutic options have been have been driven by Phase 2 and 3 clinical trials of new drug classes, particularly sphingosine-1-phosphate (S1P) modulators and interleukin-23 (IL-23) inhibitors. METHODS: This review synthesizes findings from Phase 2 and 3 clinical trials conducted up to early 2024, focusing on the impact of S1P modulators and IL-23 inhibitors on IBD management. Drugs such as ozanimod, etrasimod, risankizumab, mirikizumab, guselkumab, and brasikumab were evaluated for their efficacy and safety profiles. RESULTS: S1P modulators, such as ozanimod and etrasimod, effectively regulate immune cell trafficking to reduce inflammation and several trials highlight their clinical effectiveness in both inducing and maintaining remission in IBD, highlighting its long-term safety and sustained therapeutic effects. Additionally, IL-23 inhibitors including risankizumab, mirikizumab, and guselkumab, which disrupt key inflammatory cytokine pathways, have already shown significant effectiveness in inducing and maintaining remission in both CD and UC, with favorable safety profiles across multiple studies, suggesting their potential as critical components in managing IBD. CONCLUSIONS: The clinical trials indicate that both S1P modulators and IL-23 inhibitors offer promising therapeutic benefits and maintain strong safety profiles, positioning them as potential cornerstone treatments for IBD. Despite these advancements, further exploration into long-term safety and the development of personalized treatment strategies is essential for maximizing clinical outcomes.

Ultrasound remission after biologic induction and long-term endoscopic remission in Crohn's disease: a prospective cohort study.

Background: The Bowel Ultrasound Score (BUSS) accurately detects therapy-related changes by using the Simple Endoscopic Score for Crohn's disease (SES-CD) as the reference standard. We aimed to evaluate ultrasound remission as a treatment target and its prediction for long-term endoscopic remission. Methods: This single-centre prospective observational study, based at a tertiary referral centre in Milan, Italy, enrolled, between March 1, 2018, and January 31, 2021, adult patients with active CD (SES-CD >2) who were starting biologics. Colonoscopy and IUS was performed at baseline and at 12 months (mean 12.8 ± 4.2). The primary outcome was the predictive value of ultrasound remission at week 12 (BUSS ≤3.52) for long-term endoscopic remission at 12 months. The International Bowel Ultrasound Segmental Activity Score (IBUS-SAS) was also calculated and optimal cut-point to detect endoscopic remission was identified through ROC analysis. Findings: 93 patients with CD were included. Of these, 22 patients (24%) achieved endoscopic remission. Week 12 ultrasound remission predicted endoscopic remission (59% compared with 41% of the patients who were not in ultrasound remission; OR 9.93, 95% CI 3.10-31.80; p < 0.001), while week 12 calprotectin values (<50, <100, <250 µg/g) did not. Week 12 ultrasound activity was associated with failure to achieve long-term endoscopic remission (NPV 87%, PPV 54%). IBUS-SAS cut-off to discriminate endoscopic remission was 22.8 (AUC 0.906). ROC curve comparison showed no-significant difference between BUSS and IBUS-SAS (p = 0.46) for detecting endoscopic remission. Interpretation: Early ultrasound remission predicts long-term endoscopic remission, making it a valuable early treatment target for clinical practice and in clinical trials. Larger multicentre validation studies are warranted to confirm these findings. Funding: None.

The learning curve for using intestinal ultrasonography.

BACKGROUND AND AIMS: Intestinal ultrasonography (IUS) is challenging to learn. This prospective study examined how the accuracy of IUS increases with operator experience ("learning curve") and if prior abdominal ultrasound experience facilitates the learning process. METHODS: The study included two trainees with limited abdominal ultrasound experience (< 50 exams) and two with extensive experience (> 500 exams). Each trainee performed 99 examinations and reported four IUS findings. An expert sonographer repeated the exam, and concordance (k) between the expert and trainees was assessed in three consecutive testing periods of 33 exams each. RESULTS: A progressive improvement in concordance was observed for all IUS findings from Period 1 to Period 3, overall and for both groups of trainees, although those with experience in abdominal ultrasound had faster learning curves. The minimum number of examinations required to achieve concordance with the expert operator for detecting increased bowel wall thickness was 84 and detecting bowel dilatation was 79. However, a minimum of 97 examinations was necessary to achieve concordance for detecting intra-abdominal complications, considered an advanced IUS competence. CONCLUSION: Basic competence in IUS can be acquired with relatively few examinations, while advanced competence requires more extensive training, particularly for gastroenterologists without abdominal ultrasound experience.