Early Ultrasound Response and Progressive Transmural Remission After Treatment With Ustekinumab in Crohn's Disease

Intestinal ultrasound in Crohn’s disease: A systematic review of its role in diagnosis, monitoring, and treatment response

BACKGROUND

Intestinal ultrasound (IUS) has gained prominence as a safe, non-invasive imaging technique for managing Crohn’s disease (CD), offering real-time evaluation without radiation exposure.

AIM

To systematically review the role of IUS in diagnosing, monitoring disease progression, assessing treatment response, and managing complications in CD.

METHODS

A literature search of PubMed and Embase databases was conducted, identifying 207 original research articles published between 1953 and June 2024. The review focused on diagnostic accuracy, disease monitoring, therapeutic utility, and advancements in IUS applications.

RESULTS

IUS has shown high diagnostic accuracy for detecting inflammation, particularly in the ileum and colon, with limitations in jejunal and rectal regions. It is effective in assessing disease activity using parameters like bowel wall thickness (BWT) and vascularity and correlates well with endoscopy and magnetic resonance enterography. IUS can predict early response to biologics, with reductions in BWT serving as an important marker. In known CD, IUS influences clinical decisions during remission, flares, and therapy evaluations. It reliably detects strictures, fistulas, and therapy-related complications. Small intestinal contrast ultrasound (SICUS) can improve the detection of strictures particularly proximal ones. Techniques such as CE-IUS and elastography enhance stricture characterization but require further validation. IUS is also useful in special scenarios like perianal fistulas, pregnancy, post-operative CD, and guiding endoscopic therapy.

CONCLUSION

IUS is a patient-friendly, cost-effective imaging tool that significantly impacts CD management across various stages. Its integration into clinical practice supports early diagnosis, disease monitoring, and therapeutic adjustments. Further studies are warranted to refine advanced techniques and standardize its application for broader use.

IL-12 family cytokines and autoimmune diseases: A potential therapeutic target?

In recent years, the discovery of IL-12 family cytokines, which includes IL-12, IL-23, IL-27, IL-35, and IL-39, whose biological functions directly or indirectly affect various autoimmune diseases. In autoimmune diseases, IL-12 family cytokines are aberrantly expressed to varying degrees. These cytokines utilize shared subunits to influence T-cell activation and differentiation, thereby regulating the balance of T-cell subsets, which profoundly impacts the onset and progression of autoimmune diseases. In such conditions, IL-12 family members are aberrantly expressed to varying degrees. By exploring their immunomodulatory functions, researchers have identified varying therapeutic potentials for each member. This review examines the physiological functions of the major IL-12 family members and their interactions, discusses their roles in several autoimmune diseases, and summarizes the progress of clinical studies involving monoclonal antibodies targeting IL-12 and IL-23 subunits currently available for treatment.

Ustekinumab in the Treatment of Crohn's Disease-A Narrative Review on Clinical Efficacy and Safety Profile

Crohn's disease (CD) is a chronic inflammatory disorder of the gastrointestinal tract that leads to significant deterioration in patients' quality of life. Biologic therapy, including the use of ustekinumab (UST), is a modern approach to treating the moderate to severe form of CD, especially in patients refractory to traditional treatments. UST, which acts as an interleukin IL-12 and IL-23 antagonist, has shown high efficacy in reducing inflammation, improving quality of life, and promoting mucosal regeneration and fistula healing. However, the use of biologic therapies, such as UST, has challenges related to the timing of treatment and patient response, including the problem of immunogenicity. To determine the clinical efficacy and safety profile of UST in the treatment of CD, a review of the literature published in the PubMed database over the last 5 years was conducted. After excluding articles that did not meet the inclusion criteria, we analyzed 42 clinical studies. The review discusses the available data on the efficacy and safety of UST, as well as its comparison with other biologic therapies, such as infliximab and adalimumab. UST, although not significantly greater to adalimumab, has lower immunogenicity and higher treatment retention. The therapeutic value of UST is also confirmed by biosimilars such as ABP 65 and FYB202, which show comparable efficacy and safety profile. The analysis of predictive biomarkers, such as serum drug levels and baseline eosinophil levels, could be an important element in the future personalization of CD treatment. The review's findings point to the importance of further research to improve the tailoring of therapies to individual patients and improve long-term treatment outcomes.

Anti-IL-12/23p40 antibodies for induction of remission in Crohn's disease

BACKGROUND

Crohn's disease (CD) is a chronic inflammatory bowel disease leading to symptoms such as abdominal pain, diarrhea, weight loss, fatigue, and complications such as strictures and fistulas. Ustekinumab (CNTO 1275) and briakinumab (ABT-874) are monoclonal antibodies that target the standard p40 subunit of the cytokines interleukin-12 and interleukin-23 (IL-12/23p40), which are involved in the pathogenesis of CD. Briakinumab has been withdrawn for the treatment of CD, making ustekinumab the only available antibody against the p40 subunit of interleukin-12 and interleukin-23 approved for this purpose.

OBJECTIVES

To assess the benefits and harms of anti-IL-12/23p40 antibodies for induction of remission in CD, as compared to no treatment, placebo, other drug treatment, or varying dosing schedules.

SEARCH METHODS

We searched the following databases: Cochrane Central Register of Controlled Trials (CENTRAL), PubMed, and MEDLINE (from inception to 2 February 2024) and Embase (from inception until 12 August 2022). We also searched ClinicalTrials.gov, WHO ICTRP, references, and conference abstracts to identify additional studies.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) of at least four weeks' duration in which monoclonal antibodies against IL-12/23p40 were compared to placebo, no treatment, or another active comparator in people with active CD. We also included trials examining different doses of antibodies against IL-12/23p40.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened studies for inclusion and extracted data. We assessed the methodological quality of the included studies using Cochrane's RoB 2 tool. The primary outcome was failure to induce clinical remission by week 8, or 6 to 12 as available. Secondary outcomes included failure to induce clinical improvement (clinical response), induction of endoscopic remission, quality of life, and adverse events, serious adverse events, and withdrawals due to adverse events. We calculated the risk ratio (RR) or risk difference (RD) and 95% confidence intervals (95% CI) for each outcome unless substantial heterogeneity was detected. We analyzed data on an intention-to-treat basis. We assessed the certainty of the evidence using the GRADE approach.

MAIN RESULTS

Eight RCTs involving a total of 3224 participants with CD met the inclusion criteria. All studies were double-blinded. We assessed the risk of bias for most outcomes as either low risk of bias or some concerns. Based on a pooled analysis of three trials, ustekinumab decreased the number of participants failing to achieve clinical remission at eight weeks when compared to placebo. Seventy-four per cent (693/938) of participants in the ustekinumab group and 87% (421/483) of those in the placebo group did not enter clinical remission (RR 0.85, 95% CI 0.81 to 0.89; 3 studies; 1421 participants; high-certainty evidence). Treatment with ustekinumab likely did not lead to more serious adverse events when compared to placebo, with 5% (48/966) and 6% (30/505) of participants affected in the ustekinumab and placebo groups, respectively (RD -0.01, 95% CI -0.03 to 0.01; 3 studies; 1471 participants; moderate-certainty evidence). A single small study in children compared two different induction doses of ustekinumab. The evidence for this outcome is very uncertain due to wide CIs. Eighty-one per cent (17/21) of participants receiving the higher induction dose (9 mg/kg or 390 mg) did not enter clinical remission at eight weeks, compared to 78% (18/23) of participants receiving the lower induction dose of 3 mg/kg or 130 mg (RR 1.03, 95% CI 0.77 to 1.39; 1 study; 44 participants; very low-certainty evidence). Separate safety data for the eight-week time point were not available for this comparison. Based on one trial comparing ustekinumab to adalimumab, the evidence is very uncertain about which is the more beneficial drug. Fifty per cent (95/191) of participants receiving ustekinumab did not enter remission compared to 52% (101/195) of participants receiving adalimumab (RR 0.96, 95% CI 0.79 to 1.17; 1 study; 386 participants; very low-certainty evidence). Separate results on adverse events at eight weeks were not reported for this comparison.

AUTHORS' CONCLUSIONS

Ustekinumab reduces the risk of people with CD failing to enter clinical remission at eight weeks. It probably does not lead to more serious adverse events when compared to placebo. There were inadequate data to conclude the more effective induction dose of ustekinumab in children. No studies evaluated adverse events at eight weeks for this comparison. There may be little to no difference between ustekinumab and other biologics, such as adalimumab or guselkumab, in inducing clinical remission at week 8, but the evidence is very uncertain, and separate data on adverse events at eight weeks were not available.

Small bowel ultrasound: friend or foe?

PURPOSE OF REVIEW

Crohn's disease (CD), requires accurate diagnosis and regular monitoring to manage disease activity, prevent complications, and improve outcomes. Intestinal ultrasound (IUS) has emerged as a noninvasive, real-time imaging modality, offering a valuable alternative to traditional diagnostic techniques such as magnetic resonance enterography (MRE), endoscopy and capsule endoscopy (CE). This review examines recent advances in IUS for the diagnosis and monitoring of small bowel CD, with a focus on its applications, benefits, and limitations.

RECENT FINDINGS

Recent studies have demonstrated that IUS provides high sensitivity and specificity in detecting key markers of disease activity, including bowel wall thickness (BWT), bowel wall flow (BWF), and bowel wall stratification (BWS). Advances in IUS techniques, such as elastography and contrast-enhanced ultrasound (CEUS), have expanded its diagnostic and prognostic capabilities, potentially enabling differentiation between inflammation and fibrosis. However, challenges remain, including operator dependency, variability in scoring systems, and reduced sensitivity for superficial mucosal abnormalities. Efforts to standardize parameters and improve training have shown promise in addressing these limitations.

SUMMARY

IUS is a critical complementary tool for assessing disease activity, transmural healing, and postoperative recurrence in small bowel CD. Its noninvasiveness, cost-effectiveness, and real time assessment make it well suited for routine clinical use. Nonetheless, further multicentre studies are needed to validate scoring systems, optimize integration with other modalities, and improve consistency across clinical settings. IUS holds significant potential for advancing personalized care in small bowel CD, though ongoing research is required to refine its applications and maximize its clinical utility.

Comparative Effectiveness of Infliximab vs Ustekinumab for Endoscopic and Transmural Remission in Biologic Naïve Crohn's Disease

BACKGROUND & AIMS

Active-comparator studies are important to clinical decision-making. We compared the effectiveness of infliximab vs ustekinumab for endoscopic and transmural remission in biologic-naïve Crohn's disease (CD).

METHODS

This was a prospective real-world cohort study that included biologic-naïve patients with CD initiating infliximab or ustekinumab therapy. We compared endoscopic remission, endoscopic response, transmural remission, transmural response, clinical remission, and C-reactive protein (CRP) remission at weeks 14 to 26 and 44 to 56, using multiple logistic regression and propensity score matching to adjust for confounders.

RESULTS

In total, 429 patients were included (283 infliximab and 146 ustekinumab). At weeks 14 to 26 and 44 to 56, no significant differences were found between infliximab and ustekinumab groups in the rates of endoscopic remission (37.5% vs 30.8%; adjusted odds ratio [aOR], 1.42; 95% confidence interval [CI], 0.89-2.25; 37.5% vs 35.6%; aOR, 1.10; 95% CI, 0.71-1.72), endoscopic response (60.8% vs 55.5%; aOR, 1.27; 95% CI, 0.83-1.95; 52.7% vs 49.3%; aOR, 1.14; 95% CI, 0.75-1.76), transmural remission (16.7% vs 14.7%; aOR, 1.23; 95% CI, 0.64-2.38; 30.0% vs 28.7%; aOR, 1.10; 95% CI, 0.65-1.87), transmural response (40.1% vs 34.1%; aOR, 1.23; 95% CI, 0.76-2.00; 47.6% vs 42.6%; aOR, 1.19; 95% CI, 0.75-1.90), and clinical remission (73.2% vs 62.3%; aOR, 1.54; 95% CI, 0.96-2.48; 73.5% vs 71.2%; aOR, 1.14; 95% CI, 0.71-1.85). The infliximab group had a higher CRP remission rate at weeks 14 to 26 (60.1% vs 61.6%; aOR, 1.85; 95% CI, 1.17-2.93), but rates were similar at weeks 44 to 56 (72.8% vs 71.4%; aOR, 0.99; 95% CI, 0.65-1.52). By week 56, treatment discontinuation rates were also comparable between the infliximab and ustekinumab groups (24.4% vs 20.5%; P = .372). Similar results were replicated in the propensity-matched cohort.

CONCLUSIONS

Infliximab and ustekinumab demonstrated similar effectiveness in achieving clinical, endoscopic, and transmural remission in biologic-naïve patients with CD.

Novel outcomes in inflammatory bowel disease

Inflammatory bowel diseases (IBD), Crohn's disease (CD), and ulcerative colitis (UC) are lifelong chronic, relapsing, and remitting conditions that culminate in disease progression in many patients. Effective management of CD and UC requires consideration of both short- and long-term treatment outcomes. Historically, short-term outcomes such as clinical and endoscopic remission and symptom relief have been evaluated in clinical trials. With the expansion of treatments targeting underlying disease pathophysiology, there is the opportunity to develop management strategies that improve disease control and patients' lives in both the short and the long term. Researchers have been examining novel outcomes for assessing the efficacy of CD and UC treatments that are important to patients, and also those that go beyond symptomatic improvements or clinical remission. These include new patient-reported outcomes for symptoms, as well as transmural/histological healing and disease clearance that can be more reflective of deeper remission states and disease modification. This review analyses published clinical studies involving patients with UC and CD treated with biologics or small molecule therapies. It highlights novel IBD endpoints employed in published clinical trials and discusses their likely value for assessing disease activity and disease modification, and as predictors of reduced risk of complications and morbidities.

Clinical Trial: The Effects of Emulsifiers in the Food Supply on Disease Activity in Crohn's Disease: An Exploratory Double-Blinded Randomised Feeding Trial

BACKGROUND

Advice to avoid dietary emulsifiers in Crohn's disease (CD) is based on preclinical data.

AIMS

To examine the effect of diets high (HED) and low (LED) in emulsifiers in the food supply on disease activity in CD.

METHODS

In a double-blinded, randomised feeding study, we randomised adults with symptomatic, sonographically active CD with ileal involvement on ≥ 2 months' stable medical therapy to 4 weeks of a HED or LED modelled on Australian healthy eating guidelines. We measured the Harvey-Bradshaw Index (HBI), sonographic indices (IBUS-SAS, bowel wall thickness), quality of life (QOL) and fatigue at baseline and study completion.

RESULTS

We randomised 24 patients, mean age 37 (95% CI 32, 41) years, 12 male, HBI 6 (6, 8), bowel wall thickness 6.0 (5.5-6.6) mm. Adherence was > 95%. Clinical remission (HBI < 5) occurred in 9/12 on HED and 7/12 on LED; 2 and 3, respectively, withdrew early with increasing gastrointestinal symptoms. IBUS-SAS fell from 51 (35, 68) to 33 (15, 51) on HED (p = 0.014) and from 57 (38, 76) to 44 (29, 59) on LED (p = 0.01). Bowel wall thickness reduced by 34% on HED and 15% on LED in those who completed the study. QOL and fatigue improved on both diets (p ≤ 0.05). There were no statistically significant differences in outcomes between diets.

CONCLUSIONS

In the context of a healthy diet, the emulsifier content had no influence over disease activity over 4 weeks in patients with CD. Recommendations to avoid emulsifiers in patients with active CD are not supported. Australian New Zealand Clinical Trials Registry (ACTRN12619001099112).

Accuracy of superb microvascular imaging (SMI) in predicting endoscopic Crohn's disease activity

BACKGROUND

Treat-to-target therapy in inflammatory bowel disease requires longitudinal assessment of disease activity and intestinal ultrasound (IUS) is a promising non-invasive and cheap technology to provide objective read-outs. Vascularization of the bowel wall is one key parameter on IUS. While this is conventionally done with Color doppler imaging, it is currently unclear whether microvascular flow imaging techniques might improve the diagnostic performance of IUS.

AIMS

To explore the utility of superb microvascular imaging (SMI) for assessing disease activity in Crohn's disease (CD).

METHODS

We performed a prospective single-center cross-sectional cohort study including 56 patients with CD. IUS was performed on the terminal ileum or sigmoid colon within 30 days of colonoscopy and the International Bowel Ultrasound (IBUS) group Segmental Activity Score (SAS) as well as SMI signals were determined and correlated to established endoscopic, clinical and biochemical read-outs of disease activity.

RESULTS

SMI scores showed superior correlation to endoscopic disease activity than Doppler imaging scores. While this did not further improve the diagnostic performance of the composite IBUS-SAS, SMI scores as a single parameter excellently predicted segmental endoscopic disease activity.

CONCLUSIONS

SMI is a highly promising tool to improve or simplify the non-invasive assessment of disease activity in CD that should further be investigated in real-world and multi-center trials.

Superb Microvascular Imaging Is Superior to Doppler Imaging in Ruling Out Ulcerative Colitis Disease Activity

BACKGROUND

There is an unmet medical need for noninvasive techniques to determine disease activity in inflammatory bowel disease (IBD) and intestinal ultrasound (IUS) has shown promising performance in this regard. In addition to parameters such as bowel wall thickness, stratification, and mesenteric fat, color Doppler signals are used to determine inflammatory activity in the gut. However, whether superb microvascular imaging (SMI), a microvascular flow imaging technique, improves the diagnostic accuracy is currently unclear.

METHODS

We performed a prospective single-center cross-sectional cohort study including 62 patients with ulcerative colitis (UC). IUS was performed on the sigmoid colon within 30 days of colonoscopy and the International Bowel Ultrasound (IBUS) group Segmental Activity Score (SAS) as well as SMI signals were determined and correlated to established endoscopic, clinical, and biochemical read-outs of disease activity.

RESULTS

Semiquantitative scoring of SMI signals had a substantial interobserver agreement between 2 blinded and expert central readers. It showed excellent correlation to endoscopic, clinical, and biochemical disease activity. While SMI did not improve the overall diagnostic performance of the IBUS-SAS to predict endoscopic disease activity, SMI alone was highly precise and superior to Doppler imaging in predicting endoscopic remission.

CONCLUSIONS

IUS is a highly precise noninvasive diagnostic tool to monitor disease activity in UC, in particular for predicting endoscopic remission. Assessing the SMI signals in the bowel wall of patients with IBD seems a promising tool to simplify IUS diagnostics in IBD that warrants further research.

Understanding the learning curve of intestinal ultrasound in inflammatory bowel disease: A comparative study between novice, regular and expert

BACKGROUND

Intestinal ultrasound (IUS) has emerged as a valuable tool for monitoring inflammatory bowel disease (IBD), but its reliability depends on the technical skills of the operator.

AIMS

This study aimed to assess the IUS learning curve of a novice briefly trained to get him familiarized with the ultrasound machine and normal/abnormal IUS images, and a gastroenterologist with formal general ultrasound training and regular IUS experience (> 200 exams), using an expert radiologist as the gold standard.

METHODS

The ULTRA-IBD study was a single-center, prospective study involving 50 consecutive IBD patients. Three successive IUS examinations were performed on each patient by the 3 operators. Inter-rater agreement on IUS disease activity was calculated using the intraclass correlation coefficient.

RESULTS

The experienced gastroenterologist demonstrated consistently good agreement with the radiologist throughout the study, while the novice failed to go beyond poor agreement after 50 examinations, although a faster learning curve was observed in patients without history of IBD surgery.

CONCLUSION

These findings highlight the difficulty of the technical performance of IUS rather than its interpretation. Comprehensive ultrasound training beforehand and between 50 and 200 examinations of experience are necessary before embarking on IUS.

Assessment of activity and severity of inflammatory bowel disease in cross-sectional imaging techniques: a systematic review

BACKGROUND AND AIMS

Cross-sectional imaging techniques, including intestinal ultrasonography (IUS), computed tomography enterography (CTE), magnetic resonance enterography (MRE), are increasingly used for the evaluation of inflammatory bowel diseases (IBD). We aimed to systematically review literature evidence on the assessment of disease activity, and/or severity through cross-sectional imaging in IBD patients, and to offer guidance on their most effective utilization.

METHODS

We performed a systematic review of PubMed, EMBASE, and Scopus to identify citations pertaining to the assessment of disease activity and/or severity at cross-sectional imaging techniques compared to a reference standard (ie, other radiological techniques, endoscopy, histopathology, and surgery) in IBD patients published until December 2023.

RESULTS

Overall, 179 papers published between 1990 and 2023 were included, with a total of 10 988 IBD patients (9304 Crohn's disease [84.7%], 1206 ulcerative colitis [11.0%], 38 IBD-U [0.3%], 440 unspecified [4.0%]). Of the 179 studies, 39 investigated IUS, 22/179 CTE, and 101/179 MRE. In the remaining papers, 2 techniques were addressed together. In 81.6% of the papers, endoscopy (with or without histopathology) was used as a reference standard. All studies included evaluated disease activity, while just over half (100/179, 55.8%) also evaluated disease severity of the addressed cross-sectional methodology. Pooled sensitivity, specificity, and overall accuracy of IUS, MRE, and CTE compared to the reference standard were 60%-99%, 60%-100%, and 70%-99%, respectively.

CONCLUSIONS

All cross-sectional imaging techniques demonstrated moderate-to-good accuracy in assessing disease activity and severity of IBD. This finding highlights the potential, especially for MRE and IUS to be widely utilized in managing IBD in both clinical practice and clinical trials.

Systematic review on definitions of intestinal ultrasound treatment response and remission in inflammatory bowel disease

BACKGROUND

Intestinal ultrasound (IUS) is emerging as a valuable tool to assess treatment response in inflammatory bowel disease (IBD) clinical trials. This study details how IUS defines response and remission to evaluate treatment efficacy in IBD patients.

METHODS

We conducted a comprehensive search of studies from 1984 to March 31, 2024, focusing on IUS use in assessing treatment efficacy in IBD.

RESULTS

A total of 51 studies were included: 31 on Crohn's disease (CD), 12 on ulcerative colitis (UC) and 8 on IBD. Ileocolonoscopy was used as a reference standard in 53% of studies. IUS-defined response was reported in 47% of studies, with the majority (71%) using changes in bowel wall thickness (BWT) and color Doppler signals (CDS) as key indicators. IUS-defined remission was reported in 53% of studies, primarily using normalization of BWT to <3 mm and CDS to grades 0 or 1 as criteria. Ultrasonographic activity scores were used in 16% of studies, including the Bowel Ultrasound Score (BUSS) in two CD studies, the International Bowel Ultrasound Segmental Activity Score (IBUS-SAS) in one CD study, and the Milan Ultrasound Criteria (MUC) in one UC study The remaining four studies used unvalidated scores without clear definitions of response or remission. Assessment times varied, most commonly at weeks 8-16, and at 6, 12, and 24 months.

CONCLUSIONS

This systematic review reveals significant variability in IUS definitions of response and remission in IBD, highlighting the need to standardize eligibility criteria and outcome measures for IUS in IBD clinical trials.

Intestinal ultrasound accurately predicts future therapy failure in Crohn's disease patients in a biologics-induced remission

BACKGROUND

Intestinal ultrasound (IUS) is used to assess disease activity, complications, and treatment follow-up in Crohn's disease (CD). Less is known about the association of disease activity on IUS with the risk of future disease relapse during biologically sustained clinical remission in CD.

AIM

The study aimed to investigate the association between IUS activity parameters and subsequent therapy failure in asymptomatic biologically treated patients with CD.

METHODS

A retrospective cohort study examined the association between IUS parameters and forthcoming therapy failure (drug discontinuation, dose escalation, corticosteroid use, hospitalization, or surgery) in CD patients on biological therapy in remission.

RESULTS

A total of 57 patients with ileal (65%) or ileocolonic (35%) CD on biological therapy were included in the study. Therapy failure occurred in 50.8% [defined as need for dose escalation (31%), drug discontinuation (51.7%), steroid use (10.5%), and hospitalization (6.8%)] during a median follow-up of 5 (SD + 9.5) months after IUS. On univariate analysis, a bowel wall thickness (BWT) of 2.5 vs. 4 mm ( P  = 0.005), the existence of an enlarged lymph node ( P  = 0.02), and the loss of bowel wall stratification ( P  = 0.01) were correlated with therapy failure. On multivariable analysis, only BWT ≥ 4 mm was associated with the risk of future treatment failure (hazard ratio, 3.7; 95% confidence interval, 0.6-15; P  = 0.02).

CONCLUSION

Our findings suggest that BWT ≥4 mm during clinical remission is associated with subsequent treatment failure in patients with CD treated with biologics. Our results support the use of IUS for monitoring CD during remission and may point to a novel threshold for predicting disease reactivation.

Endoscopic diagnosis and management of adult inflammatory bowel disease: a consensus document from the American Society for Gastrointestinal Endoscopy IBD Endoscopy Consensus Panel

Endoscopy plays a key role in diagnosis, monitoring of disease activity, assessment of treatment response, dysplasia surveillance, postoperative evaluation, and interventional therapy for patients with inflammatory bowel disease (IBD). Clinical practice patterns in the endoscopic management of IBD vary. A panel of experts consisting of IBD specialists, endoscopists, and GI pathologists participated in virtual conferences and developed this modified Delphi-based consensus document to address endoscopic aspects of IBD management.

Point-of-Care Ultrasound in Gastroenterology and Hepatology

Point-of-care ultrasound (POCUS) is changing the practice of nearly all specialties and is increasingly being incorporated as a bedside tool by more gastroenterologists and hepatologists. POCUS is most often used to answer focused diagnostic questions, supplement the traditional physical examination, and guide performance of invasive bedside procedures. This review describes several common POCUS applications used in gastroenterology and hepatology, as well as some novel applications that warrant further investigation.

[Treatment of severe flares in Crohn's disease and ulcerative colitis]

BACKGROUND

In chronic inflammatory bowel diseases (IBD), severe flares are characterized by intense inflammatory activity and a high disease burden for patients. Treatment addresses both short-term goals (e.g., symptom reduction, prevention of complications) and long-term goals (sustained clinical steroid-free remission and healing of inflammatory lesions, known as "mucosal healing").

OBJECTIVE OF THE STUDY

To present evidence-based, targeted diagnostics and stepwise treatment of severe flares in Crohn's disease (CD) and ulcerative colitis (UC), in order to prevent complications, including mortality, and to achieve rapid remission.

MATERIALS AND METHODS

Selective literature review, including German and European guidelines for the treatment of severe flares.

RESULTS AND DISCUSSION

After ruling out complications (e.g., infections, strictures, abscesses, toxic megacolon), based on a structured assessment of disease severity, intravenous steroid therapy is indicated in severe acute flares for both CD and UC, which should lead to improvement within the first 72 h. If no improvement occurs, medical therapy must be intensified. Various therapeutics, including biologics targeting tumor necrosis factor (TNF)-α, α4ß7 integrins, interleukin (IL)-12/23 or IL-23, as well as Janus kinase (JAK) inhibitors, sphingosine 1‑phosphate receptor (S1PR) modulators, and calcineurin inhibitors, are available today, but there is no clear algorithm preferring one drug for CD or UC. Instead, treatment should be selected based on approvals, the patient's medical history, prior treatment, risk profile, and potential complications. Surgical options must always be considered as part of close interdisciplinary care.

International expert guidance for defining and monitoring small bowel strictures in Crohn's disease on intestinal ultrasound: a consensus statement

BACKGROUND

Diagnostic imaging using CT enterography, magnetic resonance enterography, and intestinal ultrasound are important tools in evaluating stricturing Crohn's disease. Definitions of strictures have been developed for CT enterography and magnetic resonance enterography. However, expert recommendations for definitions and treatment response of strictures on intestinal ultrasound are not available. The aim of this study was to standardise definitions, diagnosis, and treatment response criteria in small bowel stricturing Crohn's disease on intestinal ultrasound.

METHODS

Using modified RAND-University of California Los Angeles Appropriateness Method, a diverse expert panel of 13 gastroenterologists, seven radiologists, and two patient representatives was assembled. A total of 466 statements on definitions and response to therapy of stricturing Crohn's disease on intestinal ultrasound were generated from a systematic review and from expert opinion, with subsequent rating for appropriateness. Two rounds of voting with an interposed survey result discussion were performed. Statements were classified as inappropriate, uncertain, or appropriate based on the median panel rating and degree of disagreement. Appropriateness was rated using a nine-point Likert scale (1 being inappropriate, 9 being highly appropriate).

FINDINGS

A naive or anastomotic small bowel Crohn's disease stricture on intestinal ultrasound is defined by the combination of bowel wall thickening, luminal narrowing, and pre-stenotic dilation. Bowel wall thickness is defined as being more than 3 mm. Luminal narrowing is defined as either a luminal diameter reduction of more than 50% in the narrowest area and relative to a normal adjacent bowel loop, or a luminal diameter of less than 1 cm. Pre-stenotic dilation is defined as more than 2·5 cm or an increase in bowel diameter relative to a normal adjacent bowel loop. Definitions for grading hyperaemia, inflammatory fat, wall stratification, intestinal ultrasound machine technical parameters, and image acquisition were also devised. Treatment response of strictures was defined as reduction in stricture length, bowel wall thickening, luminal narrowing, pre-stenotic dilation, and motility abnormalities.

INTERPRETATION

To our knowledge, this is the first intestinal ultrasound appropriateness rating exercise conducted for defining, diagnosing, and measuring response to therapy in small bowel stricturing Crohn's disease and informs future clinical use and intestinal ultrasound index development for clinical trials.

FUNDING

Leona M and Harry B Helmsley Charitable Trust.

Dissecting Innate and Adaptive Immunity in Inflammatory Bowel Disease: Immune Compartmentalization, Microbiota Crosstalk, and Emerging Therapies

The intestinal immune system is the largest immune organ in the human body. Excessive immune response to intestinal cavity induced by harmful stimuli including pathogens, foreign substances and food antigens is an important cause of inflammatory diseases such as celiac disease and inflammatory bowel disease (IBD). Although great progress has been made in the treatment of IBD by some immune-related biotherapeutic products, yet a considerable proportion of IBD patients remain unresponsive or immune tolerant to immunotherapeutic strategy. Therefore, it is necessary to further understand the mechanism of immune cell populations involved in enteritis, including dendritic cells, macrophages and natural lymphocytes, in the steady-state immune tolerance of IBD, in order to find effective IBD therapy. In this review, we discussed the important role of innate and adaptive immunity in the development of IBD. And the relationship between intestinal immune system disorders and microflora crosstalk were also presented. We also focus on the new findings in the field of T cell immunity, which might identify novel cytokines, chemokines or anti-cytokine antibodies as new approaches for the treatment of IBD.

Assessment of outcomes in Crohn's disease: A systematic review of randomized clinical trials to inform a multiple outcome framework

Longstanding disease control in Crohn's disease (CD) is challenging and requires understanding treatment efficacy and outcomes assessment. With multiple novel therapeutic options, rigorous evaluation of outcomes in randomized controlled trials (RCTs) is crucial to inform clinical practice. This study systematically reviewed RCTs focusing on CD outcomes to elucidate the breadth and depth of reported outcomes and measurement instruments. A systematic search was conducted on MEDLINE and Scopus for RCTs published from 1 January 2000 to 31 January 2023. Eligible studies included full-text articles with at least 50 adult CD patients. Primary and secondary outcomes, along with their measurement instruments, were categorized according to the Outcome Measures in Rheumatology Filter 2.1 framework. From 88 included studies, 393 outcomes were analyzed. Clinical outcomes, such as clinical remission and response, were the most prevalent (50.6%); biomarkers (11.5%) and patient-reported outcomes (10.2%) were also assessed. Other outcomes included disease behavior and complications (2%), endoscopy (10.4%), histology (0.5%), radiology (1.3%), healthcare utilization (3.8%), and therapy-related safety (6.9%). Composite outcomes showed an increasing trend, reflecting a shift toward comprehensive evaluations. Coprimary endpoints, including clinical symptoms and mucosal inflammation, were reported in 21 of 88 studies. This review highlights the evolving landscape of outcome assessment in CD RCTs, emphasizing the increasing complexity of outcomes. The prominence of composite outcomes underscores efforts to capture the multidimensional nature of CD. These findings will inform the second stage of a two-round e-Delphi aimed at prioritizing key domains and outcomes for developing a multiple-component outcome for RCTs in CD research.

Defining mucosal healing in randomized controlled trials of inflammatory bowel disease: A systematic review and future perspective

BACKGROUND

Mucosal healing (MH) is an established treatment goal in inflammatory bowel disease (IBD). However, various definitions of MH exist. We aimed to identify how MH is defined in randomized controlled trials (RCTs) in ulcerative colitis (UC) and Crohn's disease (CD).

METHODS

We searched MEDLINE, EMBASE, and the Cochrane library from inception to December 2023 for phase 2 and 3 RCTs of advanced therapies in IBD.

RESULTS

One hundred forty-four studies were included, 72 in UC and 72 in CD, published between 1997 and 2023. In UC, 64% (46/72) RCTs reported MH as an endpoint. 12 definitions of MH were found, from endoscopic assessment alone (35/46; 76%) to the more recent combination of histology and endoscopy (10/46; 22%). 96% (44/46) of studies used the Mayo Endoscopic Subscore. In CD, reporting of MH lagged behind UC, with only 12% (9/72) of trials specifically defining MH as an endpoint, 7 as "absence of ulceration," 2 as Simplified Endoscopic Score for CD score ≤2 or 0. Histological assessment was performed in 3 RCTs of CD. Centralized reading of endoscopy was used in 48% (35/72) of RCTs of UC and 22% (16/72) of CD. Only 1 RCT included transmural healing as an endpoint.

CONCLUSIONS

A standard definition of MH in IBD is lacking. Definitions have evolved particularly in UC, which now includes the addition of histological evaluation. Transmural healing holds promise as a future target in CD. We support a greater standardization of definitions as we expect endpoints to become increasingly stringent and multimodal with computers automating the assessment.

Imaging in Inflammatory Bowel Disease

The incidence of inflammatory bowel disease (IBD) is rising globally. We need more tools and techniques in our armamentarium for early diagnosis, tight monitoring, and to assess disease complications of IBD. This article reviews the role of cross-sectional imaging, mainly computed tomography, MRI, and intestinal ultrasound (IUS) in IBD and its advantages, disadvantages, and limitations. While popular in other parts of the world, IUS is underutilized in the United States. It is safe, accurate, can be repeated multiple times and provides quick and actionable results in IBD care without the risk of radiation and contrast.

Baseline and Postinduction Intestinal Ultrasound Findings Predict Long-term Transmural and Mucosal Healing in Patients With Crohn's Disease

BACKGROUND

Intestinal ultrasound (IUS) is becoming a standard assessment tool in Crohn's disease (CD), but limited data exist on its ability to predict long-term objective outcomes. Therefore, we aimed to investigate the predictive value of IUS findings for long-term transmural healing (TH) and mucosal healing (MH) in CD.

METHODS

We prospectively included consecutive CD patients with active endoscopic disease and bowel wall thickness (BWT) >3.0 mm, initiating infliximab. Intestinal ultrasound parameters (ie, BWT, inflammatory mesenteric fat [i-fat], bowel blood flow and stratification) and International Bowel Ultrasound Segmental Activity Score (IBUS-SAS) were collected at baseline, after 14 to 26 weeks (visit 1, postinduction) and 44 to 56 weeks (visit 2). Transmural healing (normalization of all IUS parameters) and MH (SES-CD ≤2) were assessed at visit 2.

RESULTS

One hundred twenty-nine patients were evaluated. At visit 2, 38.0% and 48.1% of patients achieved TH and MH, respectively. All the IUS parameters and IBUS-SAS showed improvement at visit 1 and visit 2 compared with the baseline (all P < .001). Multivariable analysis found that presence of i-fat at baseline (odds ratio [OR], 0.57; P = .008) and greater postinduction BWT (OR, 0.24; P < .001) were negative predictors for TH, while higher baseline (OR, 0.98; P = .013) and postinduction (OR, 0.94; P < .001) IBUS-SAS predicted negatively for MH. Postinduction BWT <4.5mm best predicted TH (AUC 0.85; P < .001), while postinduction IBUS-SAS <25.0 best predicted MH (AUC 0.82; P < .001). Moreover, colonic disease was associated with higher risk of TH (OR, 2.55; P = .027), and disease duration >24 months with lower risk of MH (OR, 0.27; P = .006).

CONCLUSIONS

Baseline and postinduction IUS findings reliably predict long-term TH and MH in patients with CD receiving infliximab.

AGA Clinical Practice Update on the Role of Intestinal Ultrasound in Inflammatory Bowel Disease: Commentary

DESCRIPTION

In the past 3 years, the use of intestinal ultrasound (IUS) for monitoring inflammatory bowel disease in clinical practice has grown substantially in the United States. This American Gastroenterological Association (AGA) Institute Clinical Practice Update (CPU) aims to review the available evidence and guidance regarding the role of intestinal ultrasound in inflammatory bowel disease care.

METHODS

This CPU was commissioned and approved by the AGA Institute Clinical Practice Updates Committee (CPUC) and the AGA Governing Board to provide timely guidance on a topic of high clinical importance to the AGA membership and underwent internal peer review by the CPUC and external peer review through standard procedures of Clinical Gastroenterology and Hepatology. This expert commentary incorporates important and recently published studies in this field, and it reflects the experiences of the multidisciplinary group of authors composed of adult and pediatric gastroenterologists.

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.

Ultrasound Characteristics Can Predict Response to Biologics Therapy in Stricturing Crohn's Disease

INTRODUCTION

Stricture is a common complication in Crohn's disease (CD). Accurate identification of strictures that poorly respond to biologic therapy is essential for making optimal therapeutic decisions. The aim of this study was to determine the association between ultrasound characteristics of strictures and their therapeutic outcomes.

METHODS

Consecutive CD patients with symptomatic strictures scheduled for biologic therapy were retrospectively recruited at a tertiary hospital. Baseline intestinal ultrasound was conducted to assess stricture characteristics, including bowel wall thickness, length, stratification, vascularity, and creeping fat wrapping angle. Patients were followed up for a minimum of 1 year, during which long-term outcomes including surgery, steroid-free clinical remission, and mucosal healing were recorded. Statistical analyses were performed.

RESULTS

A total of 43 patients were enrolled. Strictures were located in the ileocecal region (39.5%), colon (37.2%), anastomosis (20.9%), and small intestine (2.3%). The median follow-up time was 17 months (interquartile range 7-25), with 27 patients (62.8%) undergoing surgery. On multivariant analysis, creeping fat wrapping angle > 180° (odds ratio: 6.2, 95% confidence interval [CI]: 1.1-41.1) and a high Limberg score (odds ratio: 2.3, 95% CI: 1.4-6.0) were independent predictors of surgery, with an area under the curve of 0.771 (95% CI: 0.602-0.940), accuracy of 83.7%, sensitivity of 96.3%, and specificity of 62.5%. On Cox survival analysis, creeping fat >180° was significantly associated with surgery (hazard ratio, 5.2; 95% CI: 1.2-21.8; P = 0.03). In addition, creeping fat was significantly associated with steroid-free clinical remission ( P = 0.015) and mucosal healing ( P = 0.06).

DISCUSSION

Intestinal ultrasound characteristics can predict outcomes in patients with stricturing CD who undertook biologic therapy.

Role of Intestinal Ultrasound for IBD Care: A Practical Approach

Intestinal ultrasound (IUS) has recently become the imaging technique of choice for patients with different types of intestinal inflammation. IUS has a high sensitivity, specificity, positive predictive value, and negative predictive value when diagnosing Crohn's disease or ulcerative colitis. Further, it is now the preferred imaging modality for routine IBD reevaluations because of its non-invasiveness, cost-effectiveness, availability (at least in Europe), and reproducibility in all age groups. However, the clinical success of IUS requires IUS training for doctors and technicians who perform IUS with a standardised description of ultrasound findings of the terminal ileum and entire colon. Complications such as abscess formation, fistulae, and stenosis can be detected by either conventional IUS or contrast-enhanced ultrasound (CEUS). Lately, several disease activity scores have been proposed for Crohn's disease, postoperative Crohn's disease, and ulcerative colitis both in adults (including elderly) and in children. IUS was successfully used in randomised clinical trials in order to measure the treatment response. Therefore, IUS now plays a central role in clinical decision making.

Multimodal dynamic ultrasound approach as predictor of response in patients with Crohn's disease treated with ustekinumab

BACKGROUND

The approval of ustekinumab (UST) has opened new options for the treatment of Crohn's disease (CD), but potential markers predicting the efficacy of this interleukin-12/23 inhibitor are lacking. Contrast-enhanced ultrasound (CEUS) is non-invasive alternative to endoscopy, demonstrating early transmural changes after treatment induction.

OBJECTIVES

We conducted a prospective monocentric study aiming to explore the value of multimodal intestinal ultrasound (IUS) in predicting the response to UST in patients with active CD who have been previously exposed to anti-tumour necrosis factor α (TNFα).

DESIGN AND METHODS

Consecutive patients with moderate-to-severe CD involving the terminal ileum who were scheduled to begin UST therapy were enrolled between January 2020 and October 2021 in the inflammatory bowel diseases outpatient centre. A complete IUS evaluation, including B-mode, Doppler, dynamic CEUS and elastography, was performed at the time of induction (T0) and after 8 (T1), 16 (T2), 24 (T3) and 48 (T4) weeks of therapy. Each IUS parameter and their variations from baseline were correlated with endoscopic response and mucosal healing after 1 year.

RESULTS

A total of 52 patients were included, 29 (55.8%) of which reached endoscopic response at T4. The univariate analysis revealed that, between T3 and T0, the percentage changes of bowel wall thickness, Limberg score, mean signal intensity, rise time, wash-in rate, C reactive protein and Harvey-Bradshaw Index were associated with long-term therapeutic outcome. Based on the above parameters, we developed an IUS score that showed a good performance in predicting 1 year-endoscopic response (area under the curve: 0.91).

CONCLUSION

Multimodal ultrasound could be helpful to predict long-term therapeutic outcome in patients with CD treated with UST.

REGISTRATION

NCT05987501.

Challenges in IBD Research 2024: Novel Technologies

Novel technology is one of the five focus areas of the Challenges in Inflammatory Bowel Disease (IBD) Research 2024 document. Building off the Challenges in IBD Research 2019 document, the Foundation aims to provide a comprehensive overview of current gaps in IBD research and deliver actionable approaches to address them with a focus on how these gaps can lead to advancements in interception, remission, and restoration for these diseases. The document is the result of a multidisciplinary collaboration from scientists, clinicians, patients, and funders and represents a valuable resource for patient-centric research prioritization. Specifically, the Novel Technologies section focuses on addressing key research gaps to enable interception and improve remission rates in IBD. This includes testing predictions of disease onset and progression, developing novel technologies tailored to specific phenotypes, and facilitating collaborative translation of science into diagnostics, devices, and therapeutics. Proposed priority actions outlined in the document include real-time measurement of biological changes preceding disease onset, more effective quantification of fibrosis, exploration of technologies for local treatment of fistulas, and the development of drug delivery platforms for precise, location-restricted therapies. Additionally, there is a strong emphasis on fostering collaboration between various stakeholders to accelerate progress in IBD research and treatment. Addressing these research gaps necessitates the exploration and implementation of bio-engineered novel technologies spanning a spectrum from materials to systems. By harnessing innovative ideas and technologies, there's a collective effort to enhance patient care and outcomes for individuals affected by IBD.

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.

Novelties and Perspectives of Intestinal Ultrasound in the Personalised Management of Patients with Inflammatory Bowel Diseases-A Systematic Review

Inflammatory bowel diseases (IBDs) affect over 4.9 million individuals worldwide. Colonoscopy (CS) is the gold-standard technique for diagnosis. The remissive-recurrent pattern of evolution raises the need for non-invasive techniques to monitor disease activity. This review aims to present the advantages of intestinal ultrasound (IUS) in managing IBDs. Our search was conducted on the PubMed, Embase, and Cochrane (CENTRAL) databases, selecting original studies comparing IUS with other imaging and invasive monitoring methods. Our search yielded 8654 results, of which 107 met the inclusion criteria. Increased bowel wall thickness (BWT) and colour Doppler signal (CDS) are discriminative for disease activity. IUS can predict disease outcomes and detect response to treatment or postoperative recurrence. Contrast-enhanced ultrasound (CEUS) and elastography help differentiate fibrotic from inflammatory stenoses. The difficult rectal assessment limits the use of IUS in ulcerative colitis (UC). Transmural healing may develop as a therapeutic target as it is associated with better outcomes. Patients are compliant with this technique, and its results correlate well with CS and other imaging methods. In conclusion, IUS proves to be essential in assessing IBD activity and treatment response, predicting outcomes and detecting complications. CEUS and elastography are researched to improve the diagnostic values of IUS.

Application of Dynamic Contrast-Enhanced Ultrasound in Evaluation the Activity of Crohn's Disease

BACKGROUND AND OBJECTIVE

The dynamic assessment of disease activity during the follow-up of patients with Crohn's disease (CD) remains a significant challenge. In this study, we aimed to identify the role of dynamic contrast-enhanced ultrasound (DCE-US) in the evaluation of activity of CD.

METHODS

In the retrospective study, patients diagnosed with CD in our hospital were included. All the diagnoses were confirmed by clinical symptoms and ileocolonoscopical results. All patients underwent intestinal ultrasound and contrast-enhanced ultrasound (CEUS) examinations within 1 week of the ileocolonoscopy examinations. Acuson Sequoia (Siemens Healthineers, Mountain View, CA, USA) and Resona R9 Elite (Mindray Medical Systems, China) with curved array and Line array transducers were used. The CEUS examination was performed with SonoVue (Bracco SpA, Milan, Italy). DCE-US analysis was performed by UltraOffice (version: 0.3-2010, Mindray Medical Systems, China) software. Two regions of interest (ROIs) were set in the anterior section of the infected bowel wall and its surrounding normal bowel wall 2 cm distant from the inflamed area. Time-intensity curves (TICs) were generated and quantitative perfusion parameters were obtained after curve fittings. The Simple Endoscopic Score for Crohn's disease (SES-CD) was regarded as the reference standard to evaluate the activity of CD. The receiver operating characteristic curve (ROC) analyses were used to determine the diagnostic efficiency of DCE-US quantitative parameters.

RESULTS

From March 2023 to November 2023, 52 CD patients were included. According to SES-CD score, all patients were divided into active group with the SES-CD score > 5 (n = 39) and inactive group SES-CD score < 5 (n = 13). Most of the active CD patients showed bowel wall thickness (BWT) > 4.2 mm (97.4%, 38/39) or mesenteric fat hypertrophy (MFH) on intestinal ultrasound (US) scan (69.2%, 27/39). Color Doppler signal of the bowel wall mostly showed spotty or short striped blood flow signal in active CD patients (56.4%, 22/39). According to CEUS enhancement patterns, most active CD patients showed a complete hyperenhancement of the entire intestinal wall (61.5%, 24/39). The TICs of active CD showed an earlier enhancement, higher peak intensity, and faster decline. Among all CEUS quantitative parameters, amplitude-derived parameters peak enhancement (PE), wash-in area under the curve (WiAUC), wash-in rate (WiR), wash-in perfusion index (WiPI), and wash-out rate (WoR) were significantly higher in active CD than in inactive CD (p < 0.05). The combined AUROC of intestinal ultrasound features and DCE-US quantitative perfusion parameters in the diagnosis of active CD was 0.987, with 97.4% sensitivity, 100% specificity, and 98.1% accuracy.

CONCLUSIONS

DCE-US with quantitative perfusion parameters is a potential useful noninvasive imaging method to evaluate the activity of Crohn's disease.

Intestinal Ultrasound and MRI for Monitoring Therapeutic Response in Luminal Crohn's Disease: A Systematic Review

PURPOSE

Cross-sectional imaging facilitates the assessment of transmural healing in patients with Crohn's disease. This systematic review addresses the utility of MRI and intestinal ultrasound (IUS) in the assessment of disease activity in response to drug therapy compared with endoscopy in patients with luminal Crohn's disease.

METHODS

Database searches were undertaken using predefined terms. Studies with ≥10 patients with luminal Crohn's disease with paired endoscopy and imaging (MRI or IUS) after treatment initiation were included. Publications were identified through searches of six bibliographic databases, all run on June 24, 2022. Records were screened on title and abstract, then full text, by two independent reviewers.

RESULTS

In total, 5,760 records were identified, with 24 studies meeting the inclusion criteria. Ten studies examined IUS and found good correlation between IUS and endoscopic remission (κ = 0.63-0.73). Early reduction in bowel wall thickness at 4 to 8 weeks predicted endoscopic response at 12 to 38 weeks (area under the receiver operating characteristic curve [AUROC], 0.77; odds ratio, 10.8; P = .01). Twelve studies examined MRI, with the Magnetic Resonance Index of Activity score having high accuracy for predicting endoscopic remission (AUROC, 0.97; sensitivity, 93%; specificity, 77%). A Simplified Magnetic Resonance Index of Activity score cutoff of ≥1 identifies active endoscopic disease (AUROC, 0.92; 95% confidence interval, 0.88-0.95; P < .0001).

CONCLUSIONS

IUS and MRI are both reliable, noninvasive modalities for assessing transmural healing in patients with Crohn's disease and are accurate in monitoring the response to drug therapy. These modalities can be used to monitor response to biologic induction therapy, with early changes predictive of response to treatment.

Clinical Application of Intestinal Ultrasound in Inflammatory Bowel Disease

PURPOSE OF REVIEW

Intestinal ultrasound (IUS) is a non-invasive, accurate, and well-tolerated tool that provides real-time assessment of inflammatory bowel disease (IBD) activity and is therefore an ideal monitoring tool. This review describes the evolving role of IUS in each phase of clinical management of IBD.

RECENT FINDINGS

Accumulating evidence has demonstrated that IUS is an excellent tool for the assessment of suspected IBD, with a very high negative predictive value. It accurately assesses disease activity, disease complications, and in the pre-treatment phase, provides a benchmark for subsequent follow-up. IUS can detect early therapeutic response and correlates well with other established monitoring modalities with arguably superior predictive capabilities and ability to assess a deeper degree of remission, transmural healing (TH). IUS has a crucial role in the management of IBD and has ushered in a new era of monitoring with more rapid evaluation and the opportunity for early optimization, deeper therapeutic targets, and improved outcomes.

Ultrasound in Pediatric Inflammatory Bowel Disease-A Review of the State of the Art and Future Perspectives

Inflammatory bowel disease (IBD) comprises a group of relapsing, chronic diseases of the gastrointestinal tract that, in addition to adults, can affect children and adolescents. To detect relapses of inflammation, these patients require close observation, frequent follow-up, and therapeutic adjustments. While reference standard diagnostics include anamnestic factors, laboratory and stool sample assessment, performing specific imaging in children and adolescents is much more challenging than in adults. Endoscopic and classic cross-sectional imaging modalities may be invasive and often require sedation for younger patients. For this reason, intestinal ultrasound (IUS) is becoming increasingly important for the non-invasive assessment of the intestine and its inflammatory affection. In this review, we would like to shed light on the current state of the art and provide an outlook on developments in this field that could potentially spare these patients more invasive follow-up procedures.

Effectiveness of Partial Enteral Nutrition as Add-On to Biologics in Patients With Refractory and Difficult-to-Treat Crohn's Disease: A Pilot Study

BACKGROUND

Partial enteral nutrition (PEN) is a well-established treatment for children with Crohn's disease (CD). However, its efficacy in adults with CD remains uncertain. We aimed to assess the effectiveness of PEN as an add-on to escalated biological therapy in adults with CD who have lost response to biologics.

METHODS

We conducted a retrospective observational study including patients who had lost response to biologics and received PEN in combination with escalated treatment, compared to those treated only with escalated therapy. The primary endpoint was steroid-free clinical remission (CR) at 24 weeks. Secondary endpoints included transmural healing (TH) and response (TR) rates along with selected clinical outcomes.

RESULTS

Forty-two patients were screened; 12 (28.6%) were excluded for complicated disease and 30 (71.4%) were included in the final analysis. Fourteen (46.7%) patients completed PEN treatment at 8 weeks, while 16 patients (53.3%) discontinued treatment due to intolerance and continued with escalation of biologic (BT group). At 24 weeks, 9 patients (64.3%) in the PEN group achieved CR, compared to 4 patients (25%) in the BT group (P = .03). The TR rate was 64.9% in the PEN group and 25% in the BT group (P = .03). Patients receiving PEN exhibited an increase in albumin levels compared to those in the BT group (Δ = 0.5; P = .02). A higher rate of therapy changes (68.7%) was observed in the BT group compared to 14.2% in the PEN group (P = .004). Prior failure to 2 lines of biological therapy was associated with adherence to PEN (OR = 1.583; CI = 1.06-2.36; P = .01).

CONCLUSIONS

In patients who had lost response to biologics, PEN in combination with escalated biologics was associated with CR and TR and improved nutritional status. Hence, the addition of PEN should be considered for patients with difficult-to-treat CD.

Automatized Detection of Crohn's Disease in Intestinal Ultrasound Using Convolutional Neural Network

INTRODUCTION

The use of intestinal ultrasound (IUS) for the diagnosis and follow-up of inflammatory bowel disease is steadily growing. Although access to educational platforms of IUS is feasible, novice ultrasound operators lack experience in performing and interpreting IUS. An artificial intelligence (AI)-based operator supporting system that automatically detects bowel wall inflammation may simplify the use of IUS by less experienced operators. Our aim was to develop and validate an artificial intelligence module that can distinguish bowel wall thickening (a surrogate of bowel inflammation) from normal bowel images of IUS.

METHODS

We used a self-collected image data set to develop and validate a convolutional neural network module that can distinguish bowel wall thickening >3 mm (a surrogate of bowel inflammation) from normal bowel images of IUS.

RESULTS

The data set consisted of 1008 images, distributed uniformly (50% normal images, 50% abnormal images). Execution of the training phase and the classification phase was performed using 805 and 203 images, respectively. The overall accuracy, sensitivity, and specificity for detection of bowel wall thickening were 90.1%, 86.4%, and 94%, respectively. The network exhibited an average area under the ROC curve of 0.9777 for this task.

CONCLUSIONS

We developed a machine-learning module based on a pretrained convolutional neural network that is highly accurate in the recognition of bowel wall thickening on intestinal ultrasound images in Crohn's disease. Incorporation of convolutional neural network to IUS may facilitate the use of IUS by inexperienced operators and allow automatized detection of bowel inflammation and standardization of IUS imaging interpretation.

To STRIDE or not to STRIDE: a critique of "treat to target" in Crohn´s disease

INTRODUCTION

The STRIDE consensus suggested to focus on mucosal healing, based on biomarkers and endoscopy, in addition to clinical endpoints as treatment target. This narrative review provides a critique of this concept in Crohn´s disease.

AREAS COVERED

We analyze and discuss the limitations of endpoints as targets, their currently limited achievability, and the controversial evidence relating to 'treat to target.' The relevant publications in Pubmed were identified in a literature review with the key word 'Crohn´s disease.'

EXPERT OPINION

All targets and endpoints have their limitations, and, even if reached, not all have unequivocally been shown to improve prognosis. The major deficiency of STRIDE is not only the lack of validation and agreement upon endpoints but little evidence of their achievability in a sizable proportion of patients by dose or timing adjustments or switching the medication. Above all, the concept should be based on clear evidence that patients indeed benefit from appropriate escalation of treatment and relevant controlled studies in this regard have been controversial. Until the STRIDE approach is proven to be superior to standard treatment focusing on clinical well-being, the field should remain reluctant and expect more convincing evidence before new targets are approved.

Monitoring of Inflammatory Bowel Disease in Pregnancy: A Review of the Different Modalities

Inflammatory Bowel Disease (IBD) significantly affects women in their reproductive years. Understanding the relationship between IBD and pregnancy is crucial, given its impact across pre-gestational, gestational, and postpartum phases. Monitoring IBD activity during pregnancy involves various modalities. This review discusses these modalities, focusing on the efficacy and safety of Small Intestine Ultrasound (IUS) as a noninvasive and reliable option. While IUS has gained popularity, its technique-sensitive nature necessitates trained staff for optimal usage.

Subcutaneous Infliximab in Refractory Crohn's Disease Patients: A Possible Biobetter?

Background

A subcutaneous formulation of infliximab (IFX-SC) approved to treat patients with inflammatory bowel disease may offer improved efficacy versus intravenous infliximab.

Methods

Patients with refractory Crohn's disease (CD, n = 32) previously treated unsuccessfully with at least 2 biologics were treated with IFX-SC and followed from baseline at Week 0 (W0) to Week 30 (W30). The study's primary endpoint was the treatment's persistence at W30, while secondary goals included the analysis of serum infliximab trough levels (TL IFX), dynamics of anti-IFX antibodies (ATIs), and clinical, serum and fecal markers of CD activity during IFX-SC treatment.

Results

Midterm treatment persistence with the continuation of treatment after W30 was 53%. TL IFX median values showed rapid, significant upward dynamics and exceeded 15.5 μg/mL at W30, whereas median ATI levels significantly declined. Among ATI-negative patients at W0 (n = 15), only one showed IFX immunogenicity with newly developed ATIs at W30. Among ATI-positive patients at W0, ATI seroconversion from ATI-positive to ATI-negative status was observed in 10 of 17 patients (58.8%). Patients who had continued IFX-SC treatment at W30 showed significant decreases in C-reactive protein (P = .0341), fecal calprotectin (P = .0002), and Harvey-Bradshaw index (P = .0029) since W0.

Conclusions

Patients with refractory CD previously treated with at least 2 biologics exhibited clinically relevant improvement with IFX-SC, which showed less immunogenic potential than IFX-IV and highly stable TL IFX.

Predicting Treatment Response in Inflammatory Bowel Diseases: Cross-Sectional Imaging Markers

Therapeutic options for inflammatory bowel diseases (IBD) have largely expanded in the last decades, both in Crohn's disease and ulcerative colitis, including multiple biological drugs targeting different inflammation pathways. However, choosing the best treatment and timing for each patient is still an undeniable challenge for IBD physicians due to the marked heterogeneity among patients and disease behavior. Therefore, early prediction of the response to biological drugs becomes of utmost importance, allowing prompt optimization of therapeutic strategies and thus paving the way towards precision medicine. In such a context, researchers have recently focused on cross-sectional imaging techniques (intestinal ultrasound, computed tomography, and magnetic resonance enterography) in order to identify predictive markers of response or non-response to biologic therapies. In this review, we aim to summarize data about imaging factors that may early predict disease behavior during biological treatment, potentially helping to define more precise and patient-tailored strategies.

Review article: Translating STRIDE-II into clinical reality - Opportunities and challenges

BACKGROUND

With the introduction of novel therapies for inflammatory bowel diseases (IBD), 'treat-to-target' strategies are increasingly discussed to improve short- and long-term outcomes in patients with IBD.

AIM

To discuss opportunities and challenges of a treat-to-target approach in light of the current 'Selecting Therapeutic Targets in Inflammatory Bowel Disease' (STRIDE-II) consensus METHODS: The 2021 update of STRIDE-II encompasses 13 evidence- and consensus-based recommendations for treat-to-target strategies in adults and children with IBD. We highlight the potential implications and limitations of these recommendations for clinical practice.

RESULTS

STRIDE-II provides valuable guidance for personalised IBD management. It reflects scientific progress as well as increased evidence of improved outcomes when more ambitious treatment goals such as mucosal healing are achieved.

CONCLUSIONS

Prospective studies, objective criteria for risk stratification, and better predictors of therapeutic response are needed to potentially render 'treating to target' more effective in the future.

Recent advances in the use of ultrasound in Crohn's disease

INTRODUCTION

A clear consensus exists on the role of IUS for the assessment and monitoring of Crohn's disease (CD) in the 'treat-to-target' strategy.

AREAS COVERED

IUS is an accurate tool for the management of CD. It is noninvasive and well tolerated. IUS has good-to-optimal inter-operator reliability either for assessing disease activity or for evaluating treatment response, especially combining Bowel Wall Thickness (BWT) and Color Doppler Signals (CDS). IUS is able to evaluate transmural remission (TR), the ultimate goal of the 'treat-to-target' strategy. Several studies confirmed its accuracy in the assessment of the post-operative recurrence (POR). Thanks to recent advances in trans-perineal ultrasound technique (TPUS), it allows to characterize peri-anal disease and its complications. Small intestine contrast ultrasound (SICUS) and contrast-enhancement ultrasound (CEUS) may improve IUS performance, particularly in stricturing or penetrating CD. Ultrasound elastography (USE) is raising interest for its accuracy in differentiating CD phenotypes (fibrotic versus inflamed).

EXPERT OPINION

IUS is a pivotal step in the management of CD, in early assessment as in therapeutic monitoring, with advantages of evaluating transmural response. Development and validation of novel ultrasound biomarkers of activity and fibrosis, especially those linked to advanced ultrasound techniques, are expected in the coming years.

Small bowel imaging in inflammatory bowel disease: updates for 2023

INTRODUCTION

Cross-sectional imaging techniques including MR and CT enterography and ultrasound are integral to Crohn's disease management, accurate, responsive, and well tolerated. They assess the full thickness of the bowel wall, perienteric environment, and distant complications. As we strive toward tighter disease control, imaging's role will expand further with transmural healing becoming an increasingly important therapeutic target.

AREAS COVERED

MEDLINE and Web of Science were searched from 2012 to 2023 inclusive. We review the evidence for cross-sectional imaging in assessing disease activity, phenotyping, and therapeutic response assessment. Emerging novel imaging applications such as quantifying enteric motility and fibrosis, prognostication, and potential utility of artificial intelligence will be covered. Recent international consensus statements highlight the need for standardized imaging reporting and definitions of transmural healing and remission. We will discuss how recent advances may be best integrated into patient care and highlight key outstanding research questions.

EXPERT OPINION

Cross-sectional imaging is established in Crohn's disease management. Research emphasis should be placed on optimal integration of imaging modalities in clinical care pathways, workforce training, definitions, and evidence for use of imaging based therapeutic targets such as transmural healing, better phenotyping of stricturing disease, and developing novel techniques, including integration of artificial intelligence.

Prognostic role of intestinal ultrasound in Crohn’s disease

The majority of patients affected by Crohn’s disease (CD) develop a chronic condition with persistent inflammation and relapses that may cause progressive and irreversible damage to the bowel, resulting in stricturing or penetrating complications in around 50% of patients during the natural history of the disease. Surgery is frequently needed to treat complicated disease when pharmacological therapy failes, with a high risk of repeated operations in time. Intestinal ultrasound (IUS), a non-invasive, cost-effective, radiation free and reproducible method for the diagnosis and follow-up of CD, in expert hands, allow a precise assessment of all the disease manifestations: Bowel characteristics, retrodilation, wrapping fat, fistulas and abscesses. Moreover, IUS is able to assess bowel wall thickness, bowel wall stratification (echo-pattern), vascularization and elasticity, as well as mesenteric hypertrophy, lymph-nodes and mesenteric blood flow. Its role in the disease evaluation and behaviour description is well assessed in literature, but less is known about the potential space of IUS as predictor of prognostic factors suggesting response to a medical treatment or postoperative recurrence. The availability of a low cost exam as IUS, able to recognize which patients are more likely to respond to a specific therapy and which patients are at high risk of surgery or complications, could be a very useful instrument in the hands of IBD physician. The aim of this review is to present current evidence about the prognostic role that IUS can show in predicting response to treatment, disease progression, risk of surgery and risk of post-surgical recurrence in CD.