Associations Among Mucosal and Transmural Healing and Fecal Level of Calprotectin in Children With Crohn's Disease

Advancements in the management of pediatric inflammatory bowel disease

INTRODUCTION

The management of pediatric inflammatory bowel disease (PIBD) has drastically changed in the last decade. The limited availability of new biologics or small molecule therapies, and concerns about durability in children has necessitated the development of other advances in management to optimize care.

AREAS COVERED

This review covers guidance for management targets and advances in optimizing biologic therapies, new medical therapies, adjuvant therapies, precision medicine and mental health concerns in PIBD. This review focused on recent advances and was not intended as a complete overview of the investigations and management of pediatric IBD.

EXPERT OPINION

Advancements include standardization of treatment goals via a treat-to-target strategy, optimizing anti-TNF biologics through combination therapy or proactive drug monitoring, earlier initiation of treatment for Crohn's disease, the emergence of new biologic/advanced therapies and a growing focus on adjuvant therapies targeting the microbiome. Future progress relies on the inclusion of children/adolescents in clinical trials to facilitate faster regulatory approval for pediatric therapies and the integration of precision medicine and mental health screening to improve patient care and outcomes.

Computed tomography enterography-based deep learning radiomics to predict stratified healing in patients with Crohn's disease: a multicenter study

OBJECTIVES

This study developed a deep learning radiomics (DLR) model utilizing baseline computed tomography enterography (CTE) to non-invasively predict stratified healing in Crohn's disease (CD) patients following infliximab (IFX) treatment.

METHODS

The study included 246 CD patients diagnosed at three hospitals. From the first two hospitals, 202 patients were randomly divided into a training cohort (n = 141) and a testing cohort (n = 61) in a 7:3 ratio. The remaining 44 patients from the third hospital served as the validation cohort. Radiomics and deep learning features were extracted from both the active lesion wall and mesenteric adipose tissue. The most valuable features were selected using univariate analysis and least absolute shrinkage and selection operator (LASSO) regression. Multivariate logistic regression was then employed to construct the radiomics, deep learning, and DLR models. Model performance was evaluated using receiver operating characteristic (ROC) curves.

RESULTS

The DLR model achieved an area under the ROC curve (AUC) of 0.948 (95% CI: 0.916-0.980), 0.889 (95% CI: 0.803-0.975), and 0.938 (95% CI: 0.868-1.000) in the training, testing, and validation cohorts, respectively in predicting mucosal healing (MH). Furthermore, the diagnostic performance of DLR model in predicting transmural healing (TH) was 0.856 (95% CI: 0.776-0.935).

CONCLUSIONS

We have developed a DLR model based on the radiomics and deep learning features of baseline CTE to predict stratified healing (MH and TH) in CD patients following IFX treatment with high accuracies in both testing and external cohorts.

CRITICAL RELEVANCE STATEMENT

The deep learning radiomics model developed in our study, along with the nomogram, can intuitively, accurately, and non-invasively predict stratified healing at baseline CT enterography.

KEY POINTS

Early prediction of mucosal and transmural healing in Crohn's Disease patients is beneficial for treatment planning. This model demonstrated excellent performance in predicting mucosal healing and had a diagnostic performance in predicting transmural healing of 0.856. CT enterography images of active lesion walls and mesenteric adipose tissue exhibit an association with stratified healing in Crohn's disease patients.

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.

Liver enzyme profiles after initiating biological treatment in children with inflammatory bowel diseases

OBJECTIVES

Biological treatments (BTs) are essential in managing pediatric inflammatory bowel diseases (PIBDs). Elevated liver enzymes sometimes succeed BT, yet elucidating studies are scarce. We addressed liver biochemistry after introducing BT and searched for their determinants.

METHODS

We identified PIBD patients receiving infliximab, adalimumab, vedolizumab, or ustekinumab at the Children's Hospital, University of Helsinki, Finland, in 2000-2023, and followed their alanine transaminase (ALT) and γ-glutamyl transpeptidase (GT) levels for 24 months. ALT was categorized based on the age- and sex-specific upper limit of normal. We disregarded 46 patients with underlying primary sclerosing cholangitis with/without autoimmune hepatitis (AIH), pretreatment AIH diagnosis, and elevated liver enzymes at the beginning of BT from the analyses.

RESULTS

Of 618 BT episodes in 403 patients, 22.2% exhibited increased ALT or GT (ALT in 117, GT in 4, and both ALT/GT in 16 episodes). Of all ALT elevations (n = 133), 41.4% occurred within the first 3 months. ALT elevation was more common after infliximab (representing 59.5% of BTs) than other BTs (25.9% vs. 14.2%, adjusted odds ratio [OR]: 2.41, 95% confidence interval [CI]: 1.23-4.72). AIH followed 1.5% (n = 9) of BT episodes. Ninety-five percent of ALT elevations resolved within 6 months. Antibiotic exposure (particularly to metronidazole) was associated with ALT elevation in general (adjusted OR: 5.76, 95% CI: 2.40-13.9) and short disease duration before starting BT with notable ALT elevation (adjusted OR: 1.10, 95% CI: 1.01-1.22).

CONCLUSIONS

Benign ALT elevation is common within 3 months after starting BT (especially infliximab) and scarcely led to cessation of the treatment. AIH is a rare finding during the first year of BT.

Comparison of an Endoscopic Scoring System and the Simplified Magnetic Resonance Index of Activity in Patients with Small Bowel Crohn's Disease

Background/Aims

The newly derived simplified magnetic resonance index of activity (MARIAs) has not been verified in comparison to balloon-assisted enteroscopy (BAE) for patients with small bowel Crohn's disease (CD). We studied the correlation of MARIAs with simple endoscopic scores for CD (SES-CD) of the ileum based on magnetic resonance enterography (MRE) and BAE in patients with small bowel CD.

Methods

Fifty patients with small bowel CD who underwent BAE and MRE concurrently within 3 months from September 2020 to June 2021 were enrolled in the study. The primary outcome was the correlation between the active score of ileal SES-CD (ileal SES-CDa)/ileal SES-CD and MARIAs based on BAE and MRE. The cutoff value for MARIAs identifying endoscopically active/severe disease, defined as ileal SES-CDa/ileal SES-CD of 5/7 or more, was analyzed.

Results

Ileal SES-CDa/ileal SES-CD and MARIAs showed strong associations (R=0.76, p<0.001; R=0.78, p<0.001). The area under the receiver operating characteristic curve of MARIAs for ileal SES-CDa ≥5 and ileal SES-CD ≥7 was 0.92 (95% confidence interval, 0.88 to 0.97) and 0.92 (95% confidence interval, 0.87 to 0.97). The cutoff value of MARIAs for detecting active/severe disease was 3. A MARIAs index value of ≥3 identified ileal SES-CDa ≥5 with a sensitivity of 85% and specificity of 87% and detected ileal SES-CD ≥7 with a sensitivity of 87% and specificity of 86%.

Conclusions

This study validated the applicability of MARIAs compared to BAE-based ileal SES-CDa/SES-CD.

Drug levels of VEDOLIZUMAB in patients with pediatric-onset inflammatory bowel disease in a real-life setting

Vedolizumab (VDZ) is used off-label in pediatric inflammatory bowel disease (PIBD). There are less data on drug levels to achieve and maintain remission in children. We aimed to study vedolizumab (VDZ) trough levels in a pediatric population in a real-life setting. We traced 50 patients with PIBD receiving VDZ treatment at our hospital, reviewed their treatment protocol, trough levels, and antidrug antibodies, and compared those to fecal calprotectin (FC) levels and achievement of corticosteroid-free maintenance therapy (CF). VDZ trough level was available from 198 samples during a median follow- up of 12.6 months. Proceeding to maintenance therapy was associated with a decline in FC but not with VDZ trough levels that were comparable between patients with FC < 100 μg/g (remission), 100-1000 μg/g, or > 1000 μg/g at 3 months (mean levels of 36.8, 28.6, and 27 μg/mL, respectively p = 0.188). At 3 months, patients achieving CF (41%) and those on corticosteroids had comparable VDZ trough levels (33 vs. 27.5 μg/mL, respectively). At 6 months, the trough level was similar in groups with FC < 100 μg/g or FC > 1000 μg/g (31.5 and 27.6 μg/mL, p = 0.859). Treatment intensification did not improve the achieved CF at 12 months. None developed drug antibodies nor discontinued the therapy for an adverse event.   Conclusion: VDZ was a well-tolerated and safe biologic treatment. A positive response on gut inflammation after induction predicted proceeding to maintenance therapy whereas trough levels did not. A VDZ trough level associated with clinical remission or continuing with VDZ treatment could not be determined. What is Known: • In pediatric inflammatory bowel disease, vedolizumab is still in off-label use. • The results on the relationship between drug levels of vedolizumab and clinical remission in pediatric patients are contradictory. What is New: • This real-life setting in pediatric-onset inflammatory bowel disease showed no benefit of therapy enhancement during a median follow-up of one year. • Trough levels of vedolizumab were not associated with therapy outcomes.

Sarcopenia assessed by computed tomography or magnetic resonance imaging is associated with the loss of response to biologic therapies in adult patients with Crohn's disease

Sarcopenia occurs in patients with Crohn's disease (CD). However, the association between sarcopenia and loss of response (LOR) to biologic agents remains unclear. This study explored such an association in CD patients. This retrospective study included 94 CD patients who received biologic therapy. The skeletal muscle cross-sectional area at the third lumbar was assessed by computed tomography or magnetic resonance imaging for sarcopenia evaluation. A LOR was defined by fecal calprotectin (FC) < 250 μg/g or >50% reduction from baseline levels or other factors, such as the used agent being replaced by other biologic agents. The association between sarcopenia and LOR was assessed by logistic regression analysis. LOR was observed in 54 patients (57.4%). The prevalence of sarcopenia in the LOR group was higher than that in response group (70.4% vs. 40.0%, p = 0.003). Sarcopenia (odds ratio [OR] = 3.89, 95% confidence interval [CI]: 1.31-11.54), Montreal L1 type (OR = 0.20, 95% CI: 0.06-0.60), perianal lesions (OR = 4.08, 95% CI: 1.31-12.70), and monocytes percentage (OR = 1.27, 95% CI: 1.02-1.57) at baseline were independent associated factors for LOR. Sarcopenia was also associated with LOR in patients who received infliximab (OR = 3.31, 95% CI: 1.11-9.87). Montreal L1 type, perianal lesions, and monocytes percentage (Model 1), and with additional consideration of sarcopenia (Model 2), were developed to predict LOR. Model 2 showed better performance than Model 1 (area under the curve [AUC] 0.82 vs. 0.75). Sarcopenia was associated with the LOR to biological agents or infliximab in adult patients with CD.

Different levels of healing in inflammatory bowel diseases: mucosal, histological, transmural, barrier and complete healing

Mucosal healing on endoscopy has emerged as a key prognostic parameter in the management of patients with IBD (Crohn's disease, ulcerative colitis/UC) and can predict sustained clinical remission and resection-free survival. The structural basis for this type of mucosal healing is a progressive resolution of intestinal inflammation with associated healing of ulcers and improved epithelial barrier function. However, in some cases with mucosal healing on endoscopy, evidence of histological activity in mucosal biopsies has been observed. Subsequently, in UC, a second, deeper type of mucosal healing, denoted histological healing, was defined which requires the absence of active inflammation in mucosal biopsies. Both levels of mucosal healing should be considered as initial events in the resolution of gut inflammation in IBD rather than as indicators of complete transmural healing. In this review, the effects of anti-inflammatory, biological or immunosuppressive agents as well as small molecules on mucosal healing in clinical studies are highlighted. In addition, we focus on the implications of mucosal healing for clinical management of patients with IBD. Moreover, emerging techniques for the analysis of mucosal healing as well as potentially deeper levels of mucosal healing such as transmural healing and functional barrier healing of the mucosa are discussed. Although none of these new levels of healing indicate a definitive cure of the diseases, they make an important contribution to the assessment of patients' prognosis. The ultimate level of healing in IBD would be a resolution of all aspects of intestinal and extraintestinal inflammation (complete healing).

The Role of Noninvasive Surrogates of Inflammation in Monitoring Pediatric Inflammatory Bowel Diseases: The Old and the New

Effectiveness of limited available therapies for pediatric inflammatory bowel disease has reached stagnation. Previous non-invasive monitoring strategies have relied upon cumbersome tools to evaluate clinical symptoms and biochemical markers that do not reflect endoscopic activity or respond quickly to treatments. Novel, patient-centric, and highly accurate, monitoring strategies with a focus on intestinal ultrasound for a direct, precise monitoring of activity to achieve disease modification are now possible. Ultimately, research on the optimal tight control monitoring strategies, individualized to each pediatric inflammatory bowel disease patient, are in development and offer a hope to potential therapeutic ceiling breakthrough on the horizon.

CTE-Based Radiomics Models Can Identify Mucosal Healing in Patients with Crohn's Disease

RATIONALE AND OBJECTIVES

To develop computed tomography enterography (CTE)-based radiomics models to assess mucosal healing (MH) in patients with Crohn's disease (CD).

MATERIALS AND METHODS

CTE images were retrospectively collected from 92 confirmed cases of CD at the post-treatment review. Patients were randomly divided into developing (n = 73) and testing (n = 19) groups. Radiomics features were extracted from the enteric phase images, and the least absolute shrinkage and selection operator (LASSO) logistic regression was applied for feature selection using 5-fold cross-validation on the developing group. The selected features were further identified from the top-ranked features and used to create improved radiomics models. Machine learning models were constructed to compare radiomics models with different radiomics features. The area under the ROC curve (AUC) was calculated to assess the predictive performance for identifying MH in CD.

RESULTS

Among the 92 CD patients included in our study, 36 patients achieved MH. The AUC of the radiomics model 1, which was based on the 26 selected radiomics features, was 0.976 for evaluating MH in the testing cohort. The AUCs of radiomics models 2 and 4, based on the top 10 and top 5 positive and negative radiomics features, were 0.974 and 0.952 in the testing cohort, respectively. The AUC of the radiomics model 3, built by removing features with r > 0.5, was 0.956 in the testing cohort. The clinical utility of the clinical radiomics nomogram was confirmed by the decision curve analysis (DCA).

CONCLUSION

The CTE-based radiomics models have demonstrated favorable performance in assessing MH in patients with CD. Radiomics features can be used as a promising imaging biomarker for MH.

Induction of Remission With Exclusive Enteral Nutrition in Children With Crohn's Disease: Determinants of Higher Adherence and Response

BACKGROUND

Exclusive enteral nutrition (EEN) is the first choice to induce remission and promote mucosal healing in pediatric Crohn's disease (CD). However, full adherence to EEN treatment may be problematic for children with CD.

METHODS

The goal of the current multicenter retrospective study was to define predictive factors of nonadherence to treatment and nonremission at the end of induction treatment. Those data together were analyzed with the ultimate goal of trying to define an individualized induction treatment for children with CD.

RESULTS

Three hundred seventy-six children with CD from 14 IBD pediatric referral centers were enrolled in the study. The rate of EEN adherence was 89%. Colonic involvement and fecal calprotectin >600 μg/g at diagnosis were found to be associated with a reduced EEN adherence. Exclusive enteral nutrition administered for 8 weeks was effective for inducing clinical remission in 67% of the total cohort. Factors determining lower remission rates were age >15 years and Pediatric Crohn's Disease Activity Index >50.

CONCLUSION

Although EEN is extremely effective in promoting disease remission, several patients' related factors may adversely impact EEN adherence and response. Personalized treatments should be proposed that weigh benefits and risks based on the patient's disease location, phenotype, and disease activity and aim to promote a rapid control of inflammation to reduce long-term bowel damage.

Managing pediatric Crohn's disease: recent insights

INTRODUCTION

Children and adolescents with Crohn's disease present unique challenges due to extensive disease at diagnosis and the effect of bowel inflammation on growth. Historical approaches with corticosteroids and immunomodulators are far less effective than early treatment with anti-TNF biologics.

AREAS COVERED

This review covers recent literature delineating the crucial role of early anti-TNF therapy in the treatment of moderate- to- severe Crohn's disease in children and adolescents. The potential risks and benefits of concomitant immunomodulators are discussed, along with therapeutic anti-TNF drug monitoring, and reassessment by endoscopy and cross-sectional imaging to evaluate success beyond symptom control.

EXPERT OPINION

Standard of care therapy for moderate-to-severe pediatric Crohn's disease now entails precision dosing of anti-TNF therapy with periodic reassessment of bowel inflammation. The role of dietary modification continues to evolve. Current and future efforts need to be directed to elucidating ways to predict response to anti-TNF therapy and quickly changing to agents with other mechanisms of action when needed. Inordinate regulatory delays in approval of new therapies approved for adults continue to handicap pediatric clinicians and frequently limits their treatment choices, or forces them to give medications "off label." Only a concerted effort by clinicians, pharma, and regulators will improve this situation.

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.

Machine and deep learning in inflammatory bowel disease

PURPOSE OF REVIEW

The Management of inflammatory bowel disease (IBD) has evolved with the introduction and widespread adoption of biologic agents; however, the advent of artificial intelligence technologies like machine learning and deep learning presents another watershed moment in IBD treatment. Interest in these methods in IBD research has increased over the past 10 years, and they offer a promising path to better clinical outcomes for IBD patients.

RECENT FINDINGS

Developing new tools to evaluate IBD and inform clinical management is challenging because of the expansive volume of data and requisite manual interpretation of data. Recently, machine and deep learning models have been used to streamline diagnosis and evaluation of IBD by automating review of data from several diagnostic modalities with high accuracy. These methods decrease the amount of time that clinicians spend manually reviewing data to formulate an assessment.

SUMMARY

Interest in machine and deep learning is increasing in medicine, and these methods are poised to revolutionize the way that we treat IBD. Here, we highlight the recent advances in using these technologies to evaluate IBD and discuss the ways that they can be leveraged to improve clinical outcomes.

Infliximab trough levels are associated with endoscopic healing but not with transmural healing at one year treatment with infliximab in pediatric patients with Crohn's disease

Introduction

It is well known that infliximab (IFX) trough levels (TLs) are associated with endoscopic healing (EH) in Crohn's disease (CD). We investigated whether IFX TLs are associated with transmural healing (TH) in pediatric patients with CD following 1-year treatment.

Methods

Pediatric patients with CD treated with IFX were included in this single-center prospective study. IFX TL tests, magnetic resonance enterography (MRE), and colonoscopies were simultaneously conducted after 1-year IFX treatment. TH was defined as a wall thickness of ≤3 mm without inflammatory signs evaluated using MRE. EH was defined as a Simple Endoscopic Score for Crohn's disease of <3 points on colonoscopy.

Results

Fifty-six patients were included. EH and TH were observed in 60.7% (34/56) and 23.2% (13/56) of patients, respectively. IFX TLs were higher in patients with EH (median, 5.6 vs. 3.4 µg/mL, P = 0.002), whereas IFX TLs showed no significant difference in patients with and without TH (median, 5.4 vs. 4.7 µg/mL, P = 0.574). No significant difference was observed in EH and TH between patients whose intervals were shortened or not. Multivariate logistic regression analysis showed that IFX TLs and disease duration to IFX initiation were associated with EH (odds ratio [OR] = 1.82, P = 0.001, and OR = 0.43, P = 0.02, respectively).

Discussion

In pediatric patients with CD, IFX TLs were associated with EH but not with TH. Further studies investigating long-term TH and proactive dosing based on therapeutic drug monitoring may clarify whether an association between IFX TLs and TH exists.

Mucosal healing assessment in Crohn's disease with normalized iodine concentration from dual-energy CT enterography: comparison with endoscopy

OBJECTIVES

Mucosal healing (MH) is an important goal in the treatment of patients with Crohn's disease (CD). Noninvasive assessment of MH with normalized iodine concentration (NIC) is unknown.

METHODS

In this retrospective study, 94 patients with diagnosed CD underwent endoscopy and dual-energy CT enterography (DECTE) at the post-infliximab treatment review. Two radiologists reviewed DECTE images by consensus for assessing diseased bowel segments of the colon or terminal ileum, and the NIC was measured. Patients were divided into transmural healing (TH), MH and non-MH groups. The diagnostic performance of the MH and non-MH groups with clinical factors and NIC was assessed utilizing receiver operating characteristic (ROC) curve analysis.

RESULTS

Of the 94 patients included in our study, 8 patients achieved TH, 34 patients achieved MH, and 52 patients did not achieve MH at the post-IFX treatment review. The area under the ROC curve (AUC), sensitivity, specificity, and accuracy values were 0.929 (95% confidence interval [CI] 0.883-0.967), 0.853, 0.827, and 0.837, respectively, for differentiating MHs from non-MHs, and the optimal NIC threshold was 0.448. The AUC of the combined model for distinguishing MHs from non-MHs in CD patients, which was based on the NIC and calprotectin, was 0.964 (95% CI 0.935-0.987).

CONCLUSIONS

The normalized iodine concentration measurement in DECTE has good performance in assessment MH in patients with CD. Iodine concentration from DECTE can be used as a radiologic marker for MH.

Transmural or mucosal healing in Crohn´s disease. Which is the goal to be pursued?

In their original report of regional ileitis, Crohn, Ginzburg and Oppenheimer already described that inflammation involved not only the ileal mucosa: "the submucosal and, to a much lesser extent, the muscular layers of the bowel are the seat of marked inflammatory hyperplastic and exudative changes", they wrote 1. Ninety years later it is well established that the inflammatory process that characterizes Crohn´s disease (CD) involves all the layers of the intestinal wall; this fact is directly related with the development of progressive digestive tract damage related to disabling complications such as strictures, fistulae, perforation, and perianal or abdominal abscesses.

The treatment principles and targets for intestinal Behcet's disease

Behcet's disease (BD) is a chronic and recurrent systemic vasculitis involving large, medium and small blood vessels as well as arteries and veins. BD with predominant gastrointestinal manifestations is diagnosed as intestinal BD, which is associated with severe complications such as massive gastrointestinal hemorrhage, perforation, and obstruction. Recently, treat-to-target (T2T) strategies have been successfully used in many chronic diseases and been suggested in the management of BD, while there are no related reviews about the global treatment strategy including treatment principles and targets for intestinal BD in detail. Herein, we review the treatment principles from the aspects of departments of Rheumatology and Gastroenterology. In addition, treatment targets of intestinal BD are reviewed from three aspects such as evaluable markers, effective markers and potency-ratio markers. Some definitions and conceptions from inflammatory bowel disease (IBD) bring us reference and enlightenments.

Pediatric inflammatory bowel disease: Fecal calprotectin response to Anti-tumor necrosis factor alpha

BACKGROUND

Fecal calprotectin (FC) is a marker of mucosal inflammation in inflammatory bowel disease (IBD). We aimed to assess the effect of anti-tumor necrosis factor alpha (TNFα) therapy on FC levels in children with IBD.

METHODS

The medical records of pediatric patients treated with anti-TNFα agents (2015-2020) were reviewed retrospectively. 63 patients had FC levels measured prior to anti TNFα induction with sequential measurements during follow-up. The main outcome measures were time to FC response according to cutoffs of 250, 150, 100 and 50 µgr/gr.

RESULTS

Mean age was 13.6 ± 3 years [females 28 (44.4%), Crohn's 55 (87%)]. Outcomes of < 250, < 150, < 100 and < 50 µgr/gr were achieved by 52 (82%), 51 (81%), 44 (70%) and 32 (50%), respectively. The median time for achieving these cutoffs was 4.8 (1.8-15.6), 7.9 (2.6-16.4), 10.0 (3.5-20.5) and 18.5 (7.0-64.7) months, respectively. Shorter time from diagnosis to treatment was associated with achievement of FC < 50 µgr/gr (p = 0.03). There was no association between age, disease type, anti-TNFα type, inflammatory markers, disease activity indices at baseline and induction anti-TNFα trough concentration and FC response.

CONCLUSIONS

FC response was achieved by the majority of patients treated with anti-TNFα within a short period of time. FC normalization in responders required almost one year.

IMPACT

Fecal calprotectin response was achieved by the majority of pediatric patients within a relatively short period of time after anti-TNFα induction and maintenance therapy. Fecal calprotectin normalization required an average period of approximately one year in responders. The faster response of fecal calprotectin is associated with shorter time from diagnosis to anti-TNFα treatment. Inflammatory bowel disease treating physicians should be aware of the relatively prolonged time to fecal calprotectin normalization and to allow enough time for anti-TNFα therapy to express its full potential prior to significant interventions.

Management and monitoring of pediatric inflammatory bowel disease in the Asia-Pacific region: A position paper by the Asian Pan-Pacific Society for Pediatric Gastroenterology, Hepatology, and Nutrition (APPSPGHAN) PIBD Working Group: Surgical management, disease monitoring, and special considerations

Disease phenotype of pediatric inflammatory bowel disease (PIBD) in children from the Asia-Pacific region differs from that of children from the West. Many parts of Asia are endemic for tuberculosis, making diagnosis and management of pediatric Crohn's disease a challenge. Current available guidelines, mainly from Europe and North America, may not be completely applicable to clinicians caring for children with PIBD in Asia due to differences in disease characteristics and regional resource constraints. This position paper is an initiative from the Asian Pan-Pacific Society for Pediatric Gastroenterology, Hepatology and Nutrition (APPSPGHAN) that aims to provide an up-to-date, evidence-based approach to PIBD in the Asia-Pacific region. A group of pediatric gastroenterologists with a special interest in PIBD performed an extensive literature search covering epidemiology, disease characteristics and natural history, management, and monitoring. Attention was paid to publications from the region with special consideration to a resource-limited setting. This current position paper deals with surgical management, disease monitoring, immunization, bone health, and nutritional issues of PIBD in Asia. A special section on differentiating pediatric Crohn's disease from tuberculosis in children is included. This position paper provides a useful guide to clinicians in the surgical management, disease monitoring, and various health issues in children with IBD in Asia-Pacific region.

Development of a multimodal machine-learning fusion model to non-invasively assess ileal Crohn's disease endoscopic activity

BACKGROUND AND OBJECTIVE

Recurrent attentive non-invasive observation of intestinal inflammation is essential for the proper management of Crohn's disease (CD). The goal of this study was to develop and evaluate a multi-modal machine-learning (ML) model to assess ileal CD endoscopic activity by integrating information from Magnetic Resonance Enterography (MRE) and biochemical biomarkers.

METHODS

We obtained MRE, biochemical and ileocolonoscopy data from the multi-center ImageKids study database. We developed an optimized multimodal fusion ML model to non-invasively assess terminal ileum (TI) endoscopic disease activity in CD from MRE data. We determined the most informative features for model development using a permutation feature importance technique. We assessed model performance in comparison to the clinically recommended linear-regression MRE model in an experimental setup that consisted of stratified 2-fold validation, repeated 50 times, with the ileocolonoscopy-based Simple Endoscopic Score for CD at the TI (TI SES-CD) as a reference. We used the predictions' mean-squared-error (MSE) and the receiver operation characteristics (ROC) area under curve (AUC) for active disease classification (TI SEC-CD≥3) as performance metrics.

RESULTS

121 subjects out of the 240 subjects in the ImageKids study cohort had all required information (Non-active CD: 62 [51%], active CD: 59 [49%]). Length of disease segment and normalized biochemical biomarkers were the most informative features. The optimized fusion model performed better than the clinically recommended model determined by both a better median test MSE distribution (7.73 vs. 8.8, Wilcoxon test, p<1e-5) and a better aggregated AUC over the folds (0.84 vs. 0.8, DeLong's test, p<1e-9).

CONCLUSIONS

Optimized ML models for ileal CD endoscopic activity assessment have the potential to enable accurate and non-invasive attentive observation of intestinal inflammation in CD patients. The presented model is available at https://tcml-bme.github.io/ML_SESCD.html.

Recent advances in clinical practice: advances in cross-sectional imaging in inflammatory bowel disease

Endoscopy remains the reference standard for the diagnosis and assessment of patients with inflammatory bowel disease (IBD), but it has several important limitations. Cross-sectional imaging techniques such as magnetic resonance enterography (MRE) and intestinal ultrasound (IUS) are better tolerated and safer. Moreover, they can examine the entire bowel, even in patients with stenoses and/or severe inflammation. A variety of cross-sectional imaging activity scores strongly correlate with endoscopic measures of mucosal inflammation in the colon and terminal ileum. Unlike endoscopy, cross-sectional techniques allow complete visualisation of the small-bowel and assess for extraintestinal disease, which occurs in nearly half of patients with IBD. Extramural findings may predict outcomes better than endoscopic mucosal assessment, so cross-sectional techniques might help identify more relevant therapeutic targets. Coupled with their high sensitivity, these advantages have made MRE and IUS the primary non-invasive options for diagnosing and monitoring Crohn's disease; they are appropriate first-line investigations, and have become viable alternatives to colonoscopy. This review discusses cross-sectional imaging in IBD in current clinical practice as well as research lines that will define the future role of these techniques.

Outcomes and Predictors of Sustained Remission After Drug Withdrawal in Pediatric Crohn Disease

OBJECTIVES

The primary aim of this study was to determine the proportion of pediatric Crohn disease (CD) subjects in sustained drug-free remission 52 weeks after stopping pharmacological therapy. We also aimed to explore the effects of the Crohn Disease Exclusion Diet (CDED) and microbiome composition on remission.

METHODS

We performed a prospective study following 18 CD patients ages 13-21 years in deep clinical remission withdrawing from immunomodulator (n = 7) or anti-TNFα (n = 11) monotherapy at two tertiary care centers. Stool for calprotectin and microbiome analyses was collected over 52 weeks. Participants followed either the CDED or free diet after drug withdrawal. The primary endpoint was sustained relapse-free drug-free remission (calprotectin <250 µg/g) at 52 weeks.

RESULTS

Seventeen participants were followed through 52 weeks with 11 (64.7%) in sustained remission. There was no improvement in remission among participants following the CDED (5/9; 55.6%), P = 0.63. By 104 weeks, only 8 (47.1 %) participants remained off immunosuppressive therapies. Analysis of shotgun metagenomic sequence data revealed that taxonomic and gene function abundance in the gut microbiome was relatively stable for participants in remission and relapse. However, a predictive model incorporating gut microbial gene pathway abundance for amino sugar/nucleotide sugar metabolism and galactose metabolism from baseline samples predicted relapse at 52 weeks with 80% accuracy.

CONCLUSIONS

After withdrawal of immunomodulator or anti-TNFα monotherapy among a small cohort of pediatric CD subjects in deep remission, nearly 65% sustained remission at 52 weeks. Baseline microbiome alterations predicted relapse. Large prospective studies are needed to better understand outcomes after treatment de-escalation.

Fecal calprotectin in predicting small bowel capsule endoscopy findings in pediatric patients with known Crohn's disease

Fecal calprotectin (FC) has been proposed as a noninvasive surrogate marker of intestinal inflammation in inflammatory bowel disease. This study aimed to assess the capability of FC in predicting small bowel capsule endoscopy (SBCE) findings in pediatric patients with known Crohn's disease (CD). We retrieved data of consecutive patients aged 2 to 17 years old with established CD who underwent SBCE from Janurary 2017 to April 2020 and had endoscopic remission on ileocolonoscopy. Sixty-eight patients were included in the analysis. There were 13 patients with a weighted pediatric CD activity index ≥ 12.5, 47 patients with FC ≥ 200 µg/g, and 45 patients with significant small bowel (SB) inflammation [Lewis score (LS) ≥ 135]. The LS correlated weakly with FC (R = 0.30, P < .05). The area under the curve of FC as a surrogate diagnostic test for LS ≥ 135 was 0.691, and the optimal FC cutoff values were 242 µg/g with the corresponding sensitivity and specificity of 78% and 65%, respectively. The area under the curve of FC for moderate-to-severe inflammatory activity in the SB was 0.718. In patients with FC level ≥ 670 µg/g, LS ≥ 790 was found in 33% (9/27) of patients, with the sensitivity and specificity of 69% and 67%, respectively. FC may be used to predict SB mucosal inflammation in pediatric patients with confirmed CD having endoscopic remission on ileocolonoscopy.

The Evaluation of Transmural Healing by Low-dose Computed Tomography Enterography in Patients with Crohn's Disease

Objective Transmural healing (TH) has been attracting attention as a new therapeutic target for Crohn's disease, but there are few clinical data on TH in Japan. We introduced low-dose computed tomography enterography (CTE) as a monitoring method for Crohn's disease and retrospectively investigated the accuracy of evaluating TH by CTE. Methods Among Crohn's disease patients who underwent low-dose CTE at our hospital from January 2009 to March 2021, 122 patients who underwent colonoscopy or balloon endoscopy within 2 weeks were included. Results of radiological and endoscopic examinations were reviewed independently by radiologists and gastrointestinal endoscopists, respectively. The concordance rate of the diagnosis between CTE and endoscopy was evaluated. Results Twenty-six patients (21.3%) achieved TH, and the kappa index was 0.743. On comparing the TH and non-TH groups, the Crohn's disease activity index (p=0.02), endoscopic healing rate (p<0.001), serum albumin (p=0.043), and serum C-reactive protein level (p=0.018) showed significant differences. Among the 122 patients, 69 (56.5%) showed concordance between the diagnosis of CTE and endoscopy, and 22 (18.0%) achieved both TH and endoscopic healing. Conclusion This study provides real-world data on Crohn's disease evaluated with low-dose CTE in Japan. The TH criterion used in this study has a high kappa coefficient and can be used reproducibly in many institutions.

Transmural healing evaluated by magnetic resonance enterography in paediatric patients with Crohn's disease receiving maintenance treatment with biologics

BACKGROUND

The optimal treatment goal in Crohn's disease (CD) is endoscopic healing (EH). However, transmural healing (TH) facilitated by the development and increasing performance of magnetic resonance enterography (MRE) is emerging as a potential treatment goal.

AIMS

To assess TH rates after 1 year of treatment by MRE and its relationship with EH in paediatric patients with CD receiving anti-tumour necrosis factor (TNF) agents, and to investigate factors associated with TH after 1 year of treatment.

METHODS

This multi-centre, prospective, observational study included Korean paediatric patients with luminal CD diagnosed at age < 19 years who were naïve to anti-TNF treatment. They simultaneously underwent ileocolonoscopy and MRE at baseline and after 1 year of treatment with biologics.

RESULTS

We included 116 patients. At 1 year, EH and TH were achieved in 59.5% (69/116) and 38.8% (45/116) of the patients, respectively. Both EH and TH was observed in 35.3% (41/116), EH without TH in 24.1% (28/116), TH without EH in 3.4% (4/116), and neither EH nor TH in 37.1% (43/116). Moreover, 59.4% (41/69) of patients who achieved EH at 1 year exhibited TH, and 91.1% (41/45) of patients who achieved TH exhibited EH. Baseline MaRIA score was associated with TH according to a multivariate analysis (OR 0.97, 95% CI 0.95-0.99, p = 0.023).

CONCLUSION

TH is a more stringent goal than EH. Regular follow-up evaluation of transmural status, and efforts to achieve TH, may alter the natural course of CD in the era of treat-to-target.

Quantitative Fecal Microbiota Profiles Relate to Therapy Response During Induction With Tumor Necrosis Factor α Antagonist Infliximab in Pediatric Inflammatory Bowel Disease

BACKGROUND

The role of intestinal microbiota in inflammatory bowel diseases is intensively researched. Pediatric studies on the relation between microbiota and treatment response are sparse. We aimed to determine whether absolute abundances of gut microbes characterize the response to infliximab induction in pediatric inflammatory bowel disease.

METHODS

We recruited pediatric patients with inflammatory bowel disease introduced to infliximab at Children's Hospital, University of Helsinki. Stool samples were collected at 0, 2, and 6 weeks for microbiota and calprotectin analyses. We defined treatment response as fecal calprotectin value <100 µg/g at week 6. Intestinal microbiota were analyzed by 16S ribosomal RNA gene amplicon sequencing using the Illumina MiSeq platform. We analyzed total bacterial counts using quantitative polymerase chain reaction and transformed the relative abundances into absolute abundances based on the total counts.

RESULTS

At baseline, the intestinal microbiota in the treatment responsive group (n = 10) showed a higher absolute abundance of Bifidobacteriales and a lower absolute abundance of Actinomycetales than nonresponders (n = 19). The level of inflammation according to fecal calprotectin showed no statistically significant association with the absolute abundances of fecal microbiota. The results on relative abundances differed from the absolute abundances. At the genus level, the responders had an increased relative abundance of Anaerosporobacter but a reduced relative abundance of Parasutterella at baseline.

CONCLUSIONS

High absolute abundance of Bifidobacteriales in the gut microbiota of pediatric patients reflects anti-inflammatory characteristics associated with rapid response to therapy. This warrants further studies on whether modification of pretreatment microbiota might improve the outcomes.

Clinical implication of radiologic complete remission on Crohn's Disease: Compared with endoscopic remission

OBJECTIVES

To determine the clinical implications of radiologic complete remission (CR) in Crohn's disease (CD) evaluated by computed tomography (CT) or magnetic resonance enterography (MRE) in comparison with endoscopic CR.

METHODS

Twenty-five CD patients who achieved endoscopic CR after medical treatment were retrospectively enrolled in this study. All patients underwent ileocolonoscopy, CT, or MRE at baseline, at the time of endoscopic CR, and during follow-up. Two radiologists assessed the mural and perienteric abnormalities on pre- and post-treatment CT or MRE in consensus. Patients were divided into radiologic CR and non-CR groups at the time of endoscopic CR. CD recurrence during subsequent follow-up periods was evaluated using clinical, laboratory, and CT/MRI findings. Statistical analysis was performed to assess whether there were significant differences in patient outcomes between the groups.

RESULTS

At the time of endoscopic CR, nine patients (mean age, 36.6 years) showed normalization of all radiologic features and were designated as the radiologic CR group. However, 16 patients (mean age: 32.9 years) showed residual CT/MRE abnormalities, suggesting persistent active inflammation, and were designated as the radiologic non-CR group. During follow-up, there was a significant difference between the groups regarding clinical outcomes (deep CR, 8/9 vs 5/16, P = 0.011; CD recurrence, 1/9 vs 14/16, P < 0.001). The mean fecal calprotectin level was significantly lower in the radiologic CR group (287.5 ug/g) than in the non-CR group (652.4 ug/g) (P = 0.023).

CONCLUSIONS

Radiologic CR can represent a better therapeutic endpoint in CD, showing superiority over endoscopic CR in predicting both clinical and biochemical outcomes.

Exploring the concept of deep remission in Crohn's disease: correlation between transmural healing and biomarkers

BACKGROUND

While mucosal healing (MH) and transmural healing (TH) predict relevant clinical outcomes in Crohn's disease (CD), little is known about the real significance and clinical impact of deep remission (DR).

OBJECTIVES

To better explore the concept of DR, toward a direct correlation between MH, TH, and biomarkers.

DESIGN

Real-world observational longitudinal study to evaluate the rate of clinical remission (CR), MH and TH, and the fecal calprotectin (FC)/C-reactive protein (CRP) levels in all consecutive CD patients on biologics.

METHODS

A receiver operating characteristic (ROC) curve was constructed to define the best FC and CRP cut-offs associated with MH and TH. Finally, patients achieving CR, MH, and TH, in association with the target FC/CRP values, were considered in DR.

RESULTS

Among 118 CD patients, CR, MH, and TH were achieved in 62.7, 44.1, and 32.2%, respectively. After 2 years, the mean FC levels decreased from 494 ± 15.4 μg/g to 260 ± 354.9 μg/g (p < 0.01). Using the ROC curve analysis, an FC cut-off value of 94 μg/g was associated with both MH [sensitivity: 94.2%, specificity: 84.8%, positive predictive value (PPV): 83.05%, negative predictive value (NPV): 94.92%, area under the curve (AUC): 0.95] and TH (sensitivity: 92.1%, specificity: 70%, PPV: 64.4%, NPV: 94.9%, AUC: 0.88). CRP < 5 mg/L was associated with both MH (sensitivity: 96.1%, specificity: 62.1%, PPV: 66.7%, NPV: 95.35%, AUC: 0.85) and TH (sensitivity: 97.4%, specificity: 52.5%, PPV: 52%, NPV: 95.35%, AUC: 0.78). When considering CD patients with concomitant CR, MH, and TH associated with an FC < 94 μg/g and CRP < 5 mg/L, this association was found identified in 33 patients (27.9%).

CONCLUSION

An FC < 94 μg/g and a normal CRP are associated with CR, MH, and TH and could be included in the definition of DR in association. So by definition, DR could be achieved in approximately 30% of CD patients during maintenance treatment with biologics.

A novel clinical radiomics nomogram at baseline to predict mucosal healing in Crohn's disease patients treated with infliximab

OBJECTIVES

Mucosal healing (MH) is currently the gold standard in Crohn's disease (CD) management. Noninvasive assessment of MH in CD patients is increasingly a concern of clinicians.

METHODS

This retrospective study included 106 patients with confirmed CD who were divided into a training cohort (n = 73) and a testing cohort (n = 33). Patient demographics were evaluated to establish a clinical model. Radiomics features were extracted from computed tomography enterography (CTE) images. A radiomics signature was constructed, and a radiomics score (Rad-score) was calculated by using the radiomics signature-based formula. A clinical radiomics nomogram was then built by incorporating the Rad-score and significant clinical features. The diagnostic performance of the three models was evaluated using receiver operating characteristic (ROC) curve analysis.

RESULTS

Of the 106 patients with CD, 37 exhibited MH after 26 weeks of infliximab (IFX) treatment. The area under the ROC curve (AUC) of the clinical radiomics nomogram for distinguishing MH from non-MH, which was based on the disease duration and Rad-score, was 0.880 (95% confidence interval [CI]: 0.809-0.943) in the training cohort and 0.877 (95% CI: 0.745-0.983) in the testing cohort. Decision curve analysis (DCA) confirmed the clinical utility of the clinical radiomics nomogram.

CONCLUSIONS

This is a preliminary study suggesting that this CTE-based radiomics model has potential value for predicting MH in CD patients. A nomogram constructed by combining radiomics signatures and clinical features can help clinicians select appropriate therapeutic strategies for CD patients.

KEY POINTS

• The disease duration (odds ratio (OR) = 0.969, 95% confidence interval (CI) = 0.943-0.995, p = 0.021) was an independent predictor of MH in the clinical model. • The AUC of the radiomics model constructed by the five radiomics features was 0.846 (95% CI: 0.759-0.921) in the training cohort and 0.817 (95% CI: 0.665-0.945) in the testing cohort for differentiating MH from non-MH. • The AUC of the clinical radiomics nomogram was 0.880 (95% CI: 0.809-0.943) in the training cohort and 0.877 (95% CI: 0.745-0.983) in the testing cohort for distinguishing MH from non-MH.

Effect of the Crohn's Disease Exclusion Diet (CDED) on the Fecal Calprotectin Level in Children with Active Crohn's Disease

(1) Background: The CDED + PEN (partial enteral nutrition) is a promising method of nutritional treatment in active Crohn’s disease (CD). An increase in fecal calprotectin (FCP) level—a marker of mucosal inflammation—happens to be the first evidence of Crohn’s disease exacerbation that appears ahead of clinical symptoms and usually co-exists with them. In this study, we present our own experience with using the CDED + PEN in the treatment of children with CD and an increased FCP level. (2) Methods: In total, 48 children (male/female: 27/21) aged 4−17 years (median value = 13.43; IQR = 4.00) were treated with CDED + PEN between June 2019 and July 2021. The main inclusion criteria for the study was active CD defined as an FCP level ≥ 250.00 µg/g. Patients with severe clinical manifestation of CD (PCDAI >40.00), as well as ones who started any new concomitant CD treatment later than at least 4 weeks before the start of dietary intervention, were excluded from the analysis. The PCDAI and fecal calprotectin level were assessed at weeks 0 and 12. The primary endpoint was ITT normalization of FCP level, i.e., a result < 250.00 µg/g at week 12. The Wilcoxon Matched Pairs Test was used for statistical analysis. (3) Results: The normalization of the FCP level was obtained in 17 children (35.42%) and an FCP level decrease of at least 50% occurred in 26 patients (54.17%). The reduction in fecal calprotectin level between week 0 and week 12 was statistically significant with a median value of 1045.00 µg/g; IQR = 1188.00, and 363.00 µg/g; IQR = 665.00, respectively (p < 0.05). Among 29 patients who were not in clinical remission at baseline, 16 (55.17%) achieved clinical remission (PCDAI < 10.00) at week 12 and 20 (68.97%) obtained a clinical response defined as at least a 12.50 point drop in PCDAI or remission. In this group, the reduction in PCDAI between baseline and week 12 was statistically significant (median value = 20.00 points; IQR = 7.50 and 5.00 points; IQR = 5.00, respectively (p < 0.05)). All patients with a normal FCP level at week 12 were in clinical remission and 16 (94.13%) of them had a normal CRP (C-reactive protein) value. In 10 children (20.83%) the full course of 12 weeks with CDED + PEN was not completed or the concomitant therapy had been started before week 12 due to the lack of efficacy/intolerance of nutritional treatment. (4) Conclusions: The 12-week course of treatment with the CDED + PEN has a beneficial effect on the fecal calprotectin level in children with active CD. The dietary intervention led to a significant decrease in the FCP level in the studied group and to the normalization of this parameter in every third patient.

The Impact of Intestinal Ultrasound on the Management of Inflammatory Bowel Disease: From Established Facts Toward New Horizons

Intestinal ultrasound (IUS) plays a crucial role as a non-invasive and accurate tool to diagnose and assess inflammatory bowel disease (IBD). The rationale for using IUS in Crohn’s disease (CD), a transmural disease, is widely acknowledged. While the use of IUS in ulcerative colitis (UC), a mucosal disease, is often underestimated, but, recently, it is increasingly expanding. In the context of a treat-to-target approach, the role of IUS is shifting toward a monitoring tool for predicting response to therapy. Hence, adjusting therapeutic strategies based on IUS response could reduce the burden related to endoscopy and speed the decision process with the ultimate goal to alter the natural course of IBD. Assessment of bowel wall thickness (BWT) is the most reliable IUS measure. However, the development of validated and reproducible sonographic scores to measure disease activity and the identification of parameters of therapeutic response remain relevant issues to implement the daily adoption of IUS in clinical practice. Accordingly, this review focuses on the current literature investigating the impact of IUS on CD with emphasis on the concept of transmural healing (TH) and the main related advantages. We further explore new insights on the role of IUS in UC and its clinical implications.

Both fecal calprotectin and fecal immunochemical tests are useful in children with inflammatory bowel disease

BACKGROUND

Noninvasive biomarkers of intestinal inflammation can reduce the number of endoscopies in children with inflammatory bowel disease (IBD). This study aimed to prospectively investigate the usefulness of fecal calprotectin (FCP) and fecal immunochemical test (FIT) in pediatric IBD.

METHODS

Patients aged 6-17 years who underwent ileocolonoscopy for established or suspected IBD were eligible for this study. Fecal samples for FCP and FIT were collected before colonoscopy.

RESULTS

A total of 251 samples were analyzed: 88 from ulcerative colitis (UC), 74 from Crohn's disease (CD), 75 from healthy controls (HC), and 14 from children with functional gastrointestinal disorders and normal colonoscopy (NC). At IBD diagnosis, both FCP and FIT were significantly higher in the newly diagnosed UC/CD group than in the HC/NC group (P < 0.001). The optimal cutoffs of FCP and FIT to predict IBD diagnosis were 217 mg/kg and 87 ng/mL, respectively. Patients without mucosal healing (MH) showed higher FCP and FIT than those with MH in both UC and CD (P < 0.001). The FCP increased exponentially as the endoscopic activity score increased. The optimal cutoff values of FCP and FIT for predicting MH were 161 mg/kg and 106 ng/mL for UC and 367 mg/kg and 57 ng/mL for CD, respectively. FCP showed better specificity than the FIT. Patients with CD and normal ileocolonoscopy had elevated FCP during active small intestinal inflammation.

CONCLUSIONS

Both FCP and FIT correlate well with endoscopic activity in pediatric patients with IBD. The FCP is a superior marker for predicting MH.

Simplified Magnetic Resonance Index of Activity Is Useful for Terminal Ileal but not Colonic Disease in Pediatric Crohn Disease

BACKGROUND

Ileocolonoscopy (IC) detects mucosal inflammation and magnetic resonance enterography (MRE) detects transmural inflammation in Crohn disease (CD). We aimed to evaluate the relationship between the simplified magnetic resonance index of activity (MARIAs) and measures of inflammation by IC in children with newly diagnosed CD.

METHODS

Retrospective review of 140 patients 6-18 years of age with CD who had baseline IC and MRE within 5 weeks of diagnosis. MARIAs was calculated for each intestinal segment (terminal ileum [TI], ascending colon, transverse colon, descending colon, sigmoid colon, rectum), defined as (1 × thickness > 3 mm) + (1 × edema) + (1 × fat stranding) + (2 × ulcers). Sensitivity and specificity were derived using receiver operating characteristic (ROC) curves to compare MARIAs to IC findings.

RESULTS

Using IC as the reference standard, the cutoff MARIAs ≥1 identified TI segments with active inflammation with 84% sensitivity, 73% specificity, 85% positive predictive value (PPV), 70% negative predictive value (NPV), and area under the curve (AUC) 0.782 (95% confidence interval [CI] 0.689-0.876). The cutoff MARIAs ≥2 identified TI segments with severe lesions with 87% sensitivity, 76% specificity, 87% PPV, 76% NPV, and AUC 0.814 (95% CI 0.712-0.916). There was poor sensitivity for all colonic segments.

CONCLUSION

The MARIAs is feasible and accurate in reflecting disease activity in the TI, but not in the colon, in children with newly diagnosed CD. Although the MARIAs may be useful for monitoring TI disease activity over time, full assessment continues to require both IC and MRE.

The gut fungal and bacterial microbiota in pediatric patients with inflammatory bowel disease introduced to treatment with anti-tumor necrosis factor-α

Pediatric inflammatory bowel disease (PIBD) is a globally increasing chronic inflammatory disease associated with an imbalanced intestinal microbiota and treated with several treatment options, including anti-tumor necrosis factor alpha (TNF-α), such as infliximab (IFX). Up to half of the patients do not respond to the drug and there are no methods for response prediction. Our aim was to predict IFX response from the gut microbiota composition since this is largely unexplored in PIBD. The gut microbiota of 30 PIBD patients receiving IFX was studied by MiSeq sequencing targeting 16S and ITS region from fecal samples collected before IFX and two and six weeks after the start of treatment. The response to IFX induction was determined by fecal calprotectin value < 100 µg/g at week six. The bacterial microbiota differed significantly between response groups, with higher relative abundance of butyrate-producing bacteria in responders compared to non-responders at baseline, validated by high predictive power (area under curve = 0.892) for baseline Ruminococcus and calprotectin. Additionally, non-responders had higher abundance of Candida, while responders had higher abundance of Saccharomyces at the end of the study. The gut microbiota composition in PIBD patients could predict response to IFX treatment in the future.

Disease Monitoring in Inflammatory Bowel Disease: Evolving Principles and Possibilities

Inflammatory bowel disease is a progressive and debilitating condition. Early and effective treatment using a treat-to-target approach is key to improving patient outcomes. Therefore, proactive monitoring is essential to ensure that treatment strategies are working and targets are being met. In this review we discuss the current monitoring tools available to us and how they can be used. We also discuss the importance of monitoring during key phases of the disease and propose an optimum treat-to-target monitoring strategy for Crohn's disease and ulcerative colitis. Regarding the advent of new technology, we discuss how this may improve our monitoring capabilities and how we envisage future monitoring strategies of inflammatory bowel diseases.

Evolving Short- and Long-Term Goals of Management of Inflammatory Bowel Diseases: Getting It Right, Making It Last

Short- and long-term treatment targets in inflammatory bowel diseases (IBDs) evolved during the last decade, shifting from symptom control to endoscopic healing and patient-centered parameters. The STRIDE-II consensus placed these targets on a timeline from initiating treatment and introduced additional targets, normalization of serum and fecal biomarkers, restoration of quality of life, prevention of disability, and, in children, restoration of growth. Transmural healing in Crohn's disease and histologic healing in ulcerative colitis currently serve as adjunct measures to gauge remission depth. However, whether early treatment according to a treat-to-target paradigm affects the natural course of IBD remains unclear, leading to the need for prospective disease-modification trials. The SPIRIT consensus defined the targets for these trials to assess the long-term impact of early treatment on quality of life, disability, disease complications, risk of neoplastic lesions, and mortality. As further data emerge about the risk-benefit balance of aiming toward deeper healing, the targets in treating IBDs may continue to shift.

Nutrition in Patients with Inflammatory Bowel Diseases: A Narrative Review

Inflammatory bowel diseases (IBD) affect the gastrointestinal tract: they include Crohn's disease (CD) and ulcerative colitis (UC). Each has a different phenotypic spectrum, characterized by gastrointestinal and extra-intestinal manifestations. People living with IBD are very interested in diet, but little is known about the impact of diet on these patients; no guidelines are available yet. In this review, we analyze the dietary patterns of patients with IBD and the approach to the choices of foods both in adults and pediatric patients. Very often, IBD patients report an intentional avoidance of gluten to manage the disease; furthermore, a proportion of IBD patients believe that dairy products worsen their symptoms and that avoidance may help the disease. They have a low compliance with the Mediterranean Diet, which is considered to have potential benefits but is little used in practice. In conclusion, the review underscores the pivotal role of nutritional counselling in IBD patients, and the importance of future clinical studies to evaluate the beneficial effects of dietary recommendations in the management of IBD.

Increased Use of Anti-Tumor Necrosis Factor Following the Implementation of the ECCO-ESPGHAN Guidelines and its Impact on the Outcome of Pediatric Crohn's Disease: A Retrospective Single-Center Study

OBJECTIVES

The first ECCO-ESPGHAN guidelines for the medical management of pediatric Crohn disease (CD) were published in 2014. Whether their implementation, and the consequent increased use of an upfront anti-tumor necrosis factor therapy, have changed the course of the disease has not been investigated yet. We aimed at comparing the evolution of pediatric CD patients diagnosed and treated before and after 2014.

METHODS

Single-center retrospective study including all children diagnosed with CD from January 2010 to December 2018. Patients diagnosed between 2010 and 2014 (group 1) were compared to those diagnosed after 2014 (group 2). For each patient, at baseline and every 6-month, number of relapses, the occurrence of complication, therapy received and biological parameters were noted, as well as any endoscopic or radiologic evaluation.

RESULTS

One hundred and fifty-four patients were included in the analysis, 78 (51%) diagnosed after 2014. The cumulative probability of a relapse-free and surgery-free course was significantly higher for patients treated according to the guidelines (log rank hazard ratio [HR] = 1,818, P = 0.003 and HR = 3,15, 95% confidence interval, P = 0.04, respectively). Mucosal healing rate was significantly higher among patients of group 2 at 1 and 2 years (P = 0.04 and P = 0.05, respectively), while no significant difference was observed for transmural healing rates, as well as for the risk of complications.

CONCLUSIONS

The implementation of the 2014 CD guidelines appears to have a significant impact on disease outcomes, with a significantly lower risk for relapse and surgery, while no effect could be observed on the risk of developing complications.

Therapy outcome related to adalimumab trough levels in pediatric patients with inflammatory bowel disease

OBJECTIVES

We evaluated the relationship between serum concentration and efficacy of adalimumab (ADA), an anti-tumor necrosis factor-alpha agent, in pediatric patients with inflammatory bowel disease (PIBD).

MATERIALS AND METHODS

This retrospective cross-sectional study traced 75 patients with PIBD (Crohn's disease, n = 57) treated with ADA at two tertiary centers in Finland in 2012-2018. Drug levels and drug antibody titers were chart-reviewed, and the treatment continuation rate of ADA therapy was evaluated. We also assessed the impact of trough levels in the first 3 months on the continuation of ADA within one year of therapy.

RESULTS

ADA was introduced at a median age of 13.4 years, and the median disease duration was 2.7 years. During the first year, 22 patients (29%) discontinued ADA due to either loss of response (20%, n = 15) or anti-drug antibody formation (5.3%, n = 4). Regarding trough levels in the first 3 months, 9/16 patients (56%) with trough levels <5 mg/L and 12/20 (60%) with trough levels <7.5 mg/L at 3 months discontinued the therapy by the end of the first year. In comparison, only 8/32 patients (25%) with trough levels >7.5 mg/L at 3 months discontinued treatment during the first year (p = .005). At the last follow-up (median 1.5 years), 52% of the 75 patients were on maintenance therapy and had a median trough level of 8.8 mg/L.

CONCLUSION

Higher trough levels in the first 3 months of adalimumab treatment are associated with lower rates of discontinuation due to loss of response during the first year.

Induction of Remission in Pediatric Crohn's Disease Patients Assessed by the Mucosal Inflammation Noninvasive Index

Mucosal healing (MH) is the main therapeutic goal of Crohn’s disease (CD). The Mucosal Inflammation Noninvasive Index (MINI) appears to be a promising tool for distinguishing MH from its inflammation. This study aims to evaluate MINI in monitoring remissions induced by exclusive enteral nutrition (EEN) in pediatric CD patients. Out of 55 newly diagnosed CD children, 31 who completed 6–8 weeks of EEN were analyzed. Clinical and biochemical data, activity of CD assessed with the Pediatric Crohn’s Disease Activity Index (PCDAI) and MINI were compared within seven days pre- and post-EEN. Response to induction therapy was defined as a decrease of PCDAI by >12.5 points. The follow-up was performed up to 12 months after EEN termination. Out of 31 children who completed 6–8 weeks of EEN, eight required corticosteroids in addition to EEN. Twenty-four patients (77%) responded to induction therapy. In responders, MINI decreased from 19 (Q1:17; Q3:22) to 12 (Q1:6; Q3:14), p < 0.001. The diagnostic accuracy of post-EEN MINI and post-EEN fecal calprotectin (FC) for treatment failure were AUC: 0.899 (95%CI: 0.737–1.000) and 0.762 (95%CI: 0.570–0.954), respectively. In the follow-up of 25 patients (80.6%), the post-EEN MINI of ≥13 points predicted CD relapse (87.5% sensitivity; 64.7% specificity), while FC had no prognostic value. MINI allows for monitoring of EEN and is superior in predicting disease relapse to FC.

Association of Fecal Calprotectin With Endoscopic and Histologic Activity in Pediatric Inflammatory Bowel Disease

Fecal calprotectin (FC) is a noninvasive marker of intestinal inflammation used for screening and ongoing monitoring of inflammatory bowel disease (IBD); it is unclear the association of specific FC values with disease activity. The aim of our study was to examine the association of FC values with endoscopic and histologic severity.

Methods

We performed a retrospective chart review of patients who had FC done between 30 days and 1 day before colonoscopy at our institution. IBD patients were graded using the simple endoscopic score for Crohn's disease or Mayo endoscopic score for ulcerative colitis. Histologic slides were graded using the Geboes method.

Results

Three-hundred thirty-one patients were included in the study and 107 had IBD. For endoscopy, median FC was lowest for all IBD patients with no disease (181 μg/g) and highest in severe disease (921 μg/g), with significant difference between no disease and moderate and severe disease (P = 0.019, 0.003), and between mild and severe disease (P = 0.012). For histology, median FC was lowest with no disease (328 μg/g) and highest in severe disease (895 μg/g), with significant difference between no disease and moderate and severe disease (P = 0.021, 0.018). The control population had a significantly lower median FC than the IBD population in endoscopic remission (35.5 versus 181 μg/g; P = 0.018).

Conclusions

There was a linear increase in FC values associated with increasing disease severity in the undifferentiated IBD cohort. Values for IBD patients in endoscopic remission were significantly different from our control population. FC may be a useful noninvasive marker to assess disease severity.

Association of Baseline Luminal Narrowing With Ileal Microbial Shifts and Gene Expression Programs and Subsequent Transmural Healing in Pediatric Crohn Disease

BACKGROUND

Transmural healing (TH) is associated with better long-term outcomes in Crohn disease (CD), whereas pretreatment ileal gene signatures encoding myeloid inflammatory responses and extracellular matrix production are associated with stricturing. We aimed to develop a predictive model for ileal TH and to identify ileal genes and microbes associated with baseline luminal narrowing (LN), a precursor to strictures.

MATERIALS AND METHODS

Baseline small bowel imaging obtained in the RISK pediatric CD cohort study was graded for LN. Ileal gene expression was determined by RNASeq, and the ileal microbial community composition was characterized using 16S rRNA amplicon sequencing. Clinical, demographic, radiologic, and genomic variables were tested for association with baseline LN and future TH.

RESULTS

After controlling for ileal location, baseline ileal LN (odds ratio [OR], 0.3; 95% confidence interval [CI], 0.1-0.8), increasing serum albumin (OR, 4; 95% CI, 1.3-12.3), and anti-Saccharomyces cerevisiae antibodies IgG serology (OR, 0.97; 95% CI, 0.95-1) were associated with subsequent TH. A multivariable regression model including these factors had excellent discriminant power for TH (area under the curve, 0.86; positive predictive value, 80%; negative predictive value, 87%). Patients with baseline LN exhibited increased Enterobacteriaceae and inflammatory and extracellular matrix gene signatures, coupled with reduced levels of butyrate-producing commensals and a respiratory electron transport gene signature. Taxa including Lachnospiraceae and the genus Roseburia were associated with increased respiratory and decreased inflammatory gene signatures, and Aggregatibacter and Blautia bacteria were associated with reduced extracellular matrix gene expression.

CONCLUSIONS

Pediatric patients with CD with LN at diagnosis are less likely to achieve TH. The association between specific microbiota, wound healing gene programs, and LN may suggest future therapeutic targets.

Nutritional Therapy in Pediatric Crohn's Disease-Are We Going to Change the Guidelines?

In recent years, there has been a significant increase in the incidence of Crohn’s disease. Despite significant medical progress, the treatment options available today do not meet the needs of all patients. Recent reports indicate that external environmental factors, including diet, are key in the pathomechanism of the disease. It was proven that the so-called Western dietary pattern is associated with an increased risk of disease. In the pediatric population, exclusive enteral nutrition is the only nutritional therapy option recommended today with proven high efficacy in inducing remission. Recent publications that indicate at least comparable efficacy and significantly better tolerability of a specialised elimination diet, the Crohn’s Disease Exclusion Diet (CDED), provide the basis for a change in recommendations. This article discusses the mechanism of action, principles of use, and scientific evidence evaluating the efficacy of CDED in the treatment of children with Crohn’s disease.

Withdrawal of Combination Immunotherapy in Paediatric Inflammatory Bowel Disease-An International Survey of Practice

OBJECTIVES

To assess current practices around the use of combination immunosuppression in paediatric inflammatory bowel disease (PIBD) with a focus on the subsequent withdrawal process.

METHODS

A web-based, 43-question survey.

RESULTS

Surveys were completed by 70 paediatric gastroenterologists (PGs) from 27 nations across Europe, North America, Oceania and Asia from 62 centres covering approximately 15,000 PIBD patients (median of 200 patients [interquartile range (IQR) 130-300] per centre). Routine use of co-immunosuppression was significantly higher with infliximab (IFX) versus adalimumab (ADL) ([61/70, 87.1%] compared with [23/70, 32.9%]; P < 0.01). Thiopurines (azathioprine [AZA] or 6-mercaptopurine) were the preferred option overall for co-immunosuppression. They were favoured with either IFX or ADL (76% and 77%, respectively) and in both ulcerative colitis (UC) and Crohn disease (CD) (84% and 69%) compared with methotrexate (MTX).Immunomodulators were the preferred choice as the initial drug to be withdrawn from the combination therapy rather than anti-tumour necrosis factor-alpha (anti-TNFα) therapy (59/67, 88% [P < 0.01]). The most common withdrawal time was after 6-12 months, with this decision usually based on clinical assessment rather than a scheduled withdrawal time (51/67, 76% vs 16/67, 24%). Indicators of mucosal healing and therapeutic drug monitoring results tended to be the most important "clinical factors" in the withdrawal decision (P = 0.05).

CONCLUSION

Most PG's favour initial withdrawal of immunomodulator (usually thiopurines) rather than biologic therapy in the step-down process, usually after 6-12 months based on sustained clinical remission. This survey precedes an in-depth, multicentre study of clinical outcomes of withdrawal of co-immunosuppression in PIBD.

Scoring Endoscopy in Pediatric Inflammatory Bowel Disease: A Way to Improve Quality

OBJECTIVES AND STUDY

There is a large interobserver variability in evaluating mucosal lesions of inflammatory bowel disease (IBD), especially in pediatric patients. This multicenter prospective observational study aims to evaluate interobserver agreement (IOA) among pediatric endoscopists in assigning validated IBD endoscopic scores in children.

METHODS

Fifteen videos of follow-up ileocolonoscopies in children with IBD were recorded and selected as cases. Eleven pediatric endoscopists from different centers blindly evaluated all videos and calculated scores: either Ulcerative Colitis Endoscopic Index of Severity (UCEIS) or Simple Endoscopic Score for Crohn Disease (SES-CD). Scores from all reviewers were compared in order to calculate IOA for general videos and specific sections. Scores from an expert adult reader were used to calculate possible reviewer's characteristics affecting scores' reliability.

RESULTS

Intraclass correlation was 0.298 (95% confidence interval [CI]: 0.13-0.55) for ulcerative colitis (UC) and 0.266 (0.11-0.52) for Crohn disease (CD). When a disease activity categorization was adopted (remission, mild, moderate, severe activity) Fleiss kappa coefficient was 0.408 (0.29-0.53) for UC and 0.552 (0.43-0.73) for CD. When stratified by item, vascular pattern of UC was the most reliable item IC: 0.624 (0.321-0.854). In multivariable analysis, none of the reviewer's characteristics affected the readers' errors.

CONCLUSIONS

This multicenter study shows low agreement among pediatric endoscopists in evaluating endoscopic scores in children with IBD. By using disease activity categorization, agreement slightly increased, mostly for CD. All readers showed a low-grade concordance with the expert adult gastroenterologist's evaluations. Future-specific training programs should be considered to increase IOA in using IBD endoscopic activity scores.

Clinical Practice Survey of Repeat Endoscopy in Pediatric Inflammatory Bowel Disease in North America

OBJECTIVES

Endoscopic remission has become a standard treatment target in inflammatory bowel disease (IBD). It is unclear how widely this practice has been adopted amongst pediatric gastroenterology providers. This study determines the frequency of repeat endoscopy in pediatric IBD and evaluates for predictive baseline characteristics of providers.

METHODS

We developed a cross-sectional survey, which was distributed via 3 national email listservs to pediatric gastroenterology providers. We obtained baseline characteristics of respondents and assessed motivations and barriers for the practice of repeat endoscopy compared with none.

RESULTS

Two hundred and thirty-eight unique respondents completed the online survey. Response rate was 11% (238 of 2300 possible participants). The majority practice in an academic setting (77%) and reported participation in ImproveCareNow (63%). Overall, 65% of respondents perform repeat endoscopy to assess for endoscopic remission in pediatric IBD as part of routine clinical practice. Fifty-six percent reported repeat endoscopy as individuals in the absence of a departmental protocol. "Symptoms are not sufficient to follow IBD patients" was reported by 82% of those who repeat endoscopy; conversely, "I perform endoscopy based on clinical, biomarker, and/or imaging trends" was reported by 81% of those who do not repeat endoscopy. The establishment of a pediatric-specific guideline was most commonly reported to change current practice, based on rank-order scoring.

CONCLUSIONS

A majority of representative providers repeat endoscopy to assess for endoscopic remission in pediatric IBD. Fewer years in practice favored repeating endoscopy. The need for North American pediatric guidelines with pediatric-specific evidence to support the long-term benefits of endoscopic remission are highlighted in this study.