Host transcriptome signatures in human faecal-washes predict histological remission in patients with IBD

BACKGROUND

Colonoscopy is the gold standard for evaluation of inflammation in inflammatory bowel diseases (IBDs), yet entails cumbersome preparations and risks of injury. Existing non-invasive prognostic tools are limited in their diagnostic power. Moreover, transcriptomics of colonic biopsies have been inconclusive in their association with clinical features.

AIMS

To assess the utility of host transcriptomics of faecal wash samples of patients with IBD compared with controls.

METHODS

In this prospective cohort study, we obtained biopsies and faecal-wash samples from patients with IBD and controls undergoing lower endoscopy. We performed RNAseq of biopsies and matching faecal-washes, and associated them with endoscopic and histological inflammation status. We also performed faecal mass-spectrometry proteomics on a subset of samples. We inferred cell compositions using computational deconvolution and used classification algorithms to identify informative genes.

RESULTS

We analysed biopsies and faecal washes from 39 patients (20 IBD, 19 controls). Host faecal-transcriptome carried information that was distinct from biopsy RNAseq and faecal proteomics. Transcriptomics of faecal washes, yet not of biopsies, from patients with histological inflammation were significantly correlated to one another (p=5.3×10-12). Faecal-transcriptome had significantly higher statistical power in identifying histological inflammation compared with transctiptome of intestinal biopsies (150 genes with area under the curve >0.9 in faecal samples vs 10 genes in biopsy RNAseq). These results were replicated in a validation cohort of 22 patients (10 IBD, 12 controls). Faecal samples were enriched in inflammatory monocytes, regulatory T cells, natural killer-cells and innate lymphoid cells.

CONCLUSIONS

Faecal wash host transcriptome is a statistically powerful biomarker reflecting histological inflammation. Furthermore, it opens the way to identifying important correlates and therapeutic targets that may be obscured using biopsy transcriptomics.

Immune function in newborns with in-utero exposure to anti-TNFα therapy

BACKGROUND AND AIM

Anti-TNFα is measurable in infants exposed in utero up to 12 months of age. Data about the exposure effect on the infant's adaptive immunity are limited. We aimed to prospectively evaluate the distribution and function of T and B cells, in infants of females with inflammatory bowel disease, in utero exposed to anti-TNFα or azathioprine.

METHODS

A prospective multi-center study conducted 2014-2017. Anti-TNFα levels were measured in cord blood, and at 3 and 12 months. T-cell repertoire and function were analyzed at 3 and 12 months by flow-cytometry, expression of diverse T cell receptors (TCR) and T-cell receptor excision circles (TREC) quantification assay. Serum immunoglobulins and antibodies for inactivated vaccines were measured at 12 months. Baseline clinical data were retrieved, and 2-monthly telephonic interviews were performed regarding child infections and growth.

RESULTS

24 pregnant females, age 30.6 (IQR 26.5-34.5) years were recruited, 20 with anti-TNFα (infliximab 8, adalimumab 12), and 4 with azathioprine treatment. Cord blood anti-TNFα was higher than maternal blood levels [4.3 (IQR 2.3-9.2) vs. 2.5 (IQR 1.3-9.7) mcg/ml], declining at 3 and 12 months. All infants had normal number of B-cells (n = 17), adequate levels of immunoglobulins (n = 14), and protecting antibody levels to Tetanus, Diphtheria, Hemophilus influenza-B and hepatitis B (n = 17). All had normal CD4+, CD8+ T-cells, and TREC numbers. TCR repertoire was polyclonal in 18/20 and slightly skewed in 2/20 infants. No serious infections requiring hospitalization were recorded.

CONCLUSION

We found that T-cell and B-cell immunity is fully mature and immune function is normal in infants exposed in utero to anti-TNFα, as in those exposed to azathioprine. Untreated controls and large-scale studies are needed to confirm these results.

Predictors of Immunogenicity to Infliximab among Patients with Inflammatory Bowel Disease: Does Ethnicity Matter?

BACKGROUND

Up to 60% of inflammatory bowel disease (IBD) patients treated with infliximab develop antibodies to infliximab (ATI), which are associated with low drug levels and loss of response (LOR). Hence, mapping out predictors of immunogenicity toward infliximab is essential for tailoring patient-specific therapy. Jewish Sephardi ethnicity, in addition to monotherapy, has been previously identified as a potential risk factor for ATI formation and infliximab failure.

OBJECTIVES

To explore the association between Jewish sub-group ethnicity among patients with IBD and the risk of infliximab immunogenicity and therapy failure. To confirm findings of a previous cohort that addressed the same question.

METHODS

This retrospective cohort study included all infliximab-treated patients of Jewish ethnicity with regular prospective measurements of infliximab trough levels and ATI. Drug and ATI levels were prospectively measured, clinical data was retrieved from medical charts.

RESULTS

The study comprised 109 Jewish patients (54 Ashkenazi, 55 Sephardi) treated with infliximab. There was no statistically significant difference in proportion of ATI between Sephardi and Ashkenazi patients with IBD (32% Ashkenazi and 33% Sephardi patients developed ATI, odds ratio [OR] 0.944, P = 0.9). Of all variables explored, monotherapy and older age were the only factors associated with ATI formation (OR 0.336, 95% confidence interval 0.145-0.778, P = 0.01, median 34 vs. 28, interquartile range 28-48, 23-35 years, P = 0.02, respectively).

CONCLUSIONS

Contrary to previous findings, Sephardi Jewish ethnicity was not identified as a risk factor for ATI formation compared with Ashkenazi Jewish ethnicity. Other risk factors remained unchanged.

Machine learning for prediction of intra-abdominal abscesses in patients with Crohn's disease visiting the emergency department

BACKGROUND

Intra-abdominal abscess (IA) is an important clinical complication of Crohn's disease (CD). A high index of clinical suspicion is needed as imaging is not routinely used during hospital admission. This study aimed to identify clinical predictors of an IA among hospitalized patients with CD using machine learning.

METHODS

We created an electronic data repository of all patients with CD who visited the emergency department of our tertiary medical center between 2012 and 2018. We searched for the presence of an IA on abdominal imaging within 7 days from visit. Machine learning models were trained to predict the presence of an IA. A logistic regression model was compared with a random forest model.

RESULTS

Overall, 309 patients with CD were hospitalized and underwent abdominal imaging within 7 days. Forty patients (12.9%) were diagnosed with an IA. On multivariate analysis, high C-reactive protein (CRP) [above 65 mg/l, adjusted odds ratio (aOR): 16 (95% CI: 5.51-46.18)], leukocytosis [above 10.5 K/μl, aOR: 4.47 (95% CI: 1.91-10.45)], thrombocytosis [above 322.5 K/μl, aOR: 4.1 (95% CI: 2-8.73)], and tachycardia [over 97 beats per minute, aOR: 2.7 (95% CI: 1.37-5.3)] were independently associated with an IA. Random forest model showed an area under the curve of 0.817 ± 0.065 with six features (CRP, hemoglobin, WBC, age, current biologic therapy, and BUN).

CONCLUSION

In our large tertiary center cohort, the machine learning model identified the association of six clinical features (CRP, hemoglobin, WBC, age, BUN, and biologic therapy) with the presentation of an IA. These may assist as a decision support tool in triaging CD patients for imaging to exclude this potentially life-threatening complication.

Epidemiology of Inflammatory Bowel Diseases in Israel: A Nationwide Epi-Israeli IBD Research Nucleus Study

BACKGROUND

There are currently no nationwide data on the epidemiology of inflammatory bowel diseases (IBD) in Israel. We aimed to determine the population-based epidemiological trends of IBD in the diverse Israeli population.

METHODS

Health-administrative data were retrieved from all 4 Israeli health maintenance organizations, insuring 98% of the population, using validated identification algorithms. National trends were determined using Joinpoint regression analysis calculating annual percent change and average annual percent change (AAPC).

RESULTS

By 2019, there were 46,074 patients with IBD in Israel, corresponding to a national prevalence of 519/100,000 (0.52%), of whom 54.1% had Crohn disease (CD) and 45.9% had ulcerative colitis (UC). The number of Jewish patients doubled from 18,701 in 2005 (354/100,000) to 38,950 (589/100,000) in 2018 (AAPC, +4.0%; P < 0.05), and the number of Arab patients increased 3-fold from 1096 (102.1/100,000) to 3534 (240.7/100,000; AAPC, +6.8%; P < 0.05) during the same years. However, the increase rate has gradually decelerated over time (annual percent change during 2005-2008, 2009-2014, and 2005-2018 was +6.7%, +4.2%, and +2.3%, respectively; P < 0.05). Pediatric prevalence increased from 37.4 to 52.2/100,000, with CD predominating in both Jews and Arabs. The incidence of CD remained stable (from 15.9/100,000 to 14.9/100,000) and the incidence of UC decreased (15.4/100,000 to 10.5/100,000 (AAPC, -3.2%; P < 0.001)). In contrast, pediatric incidence of CD increased from 7.3/100,000 to 8.3/100,000 (AAPC, +1.9%; P < 0.05) and that of UC increased from 2.6 to 4.4/100,000 (AAPC, +5.8%; P < 0.05).

CONCLUSIONS

The IBD prevalence rate in Israel is still increasing but gradually decelerating, probably due to the decreasing overall IBD incidence. Nonetheless, incidence rate in children is still increasing. Ongoing narrowing in the rates between Jews and Arabs over time may indicate shared environmental factors.

Association of Infliximab and Vedolizumab Trough Levels with Reported Rates of Adverse Events: A Cross-Sectional Study

Infliximab and vedolizumab are effective treatments for inflammatory bowel disease (IBD), although associated with adverse events (AE). While low or non-existent drug levels and positive antidrug antibodies have been associated with therapeutic failure, there is no clear association between higher drug levels and AE. A cross-sectional study consisting of Crohn’s disease (CD) and ulcerative colitis (UC) patients receiving infliximab or vedolizumab at the Sheba Medical Center was performed. Patients completed a questionnaire regarding AEs related to biological therapy. Serum trough levels obtained on the same day were analyzed. Objective measures of outcomes were retrieved from medical records. Questionnaires were completed by infliximab (n = 169) and vedolizumab (n = 88)-treated therapy patients. Higher infliximab levels were only numerically associated with the occurrence of at least one AE (p = 0.08). When excluding fatigue and abdominal pain, higher infliximab levels were statistically associated with the occurrence of at least one AE (p = 0.03). Vedolizumab drug levels > 18 μg/mL were also linked with the occurrence of more AEs. No specific association was observed between the increased levels of either infliximab or vedolizumab and specific AEs (neurological symptoms, upper GI symptoms, infectious complications, and musculoskeletal symptoms). As significant AEs are very rare, additional multi-center studies are required.

A Convolutional Neural Network Deep Learning Model Trained on CD Ulcers Images Accurately Identifies NSAID Ulcers

Background and Study Aims: Deep learning (DL) for video capsule endoscopy (VCE) is an emerging research field. It has shown high accuracy for the detection of Crohn's disease (CD) ulcers. Non-steroidal anti-inflammatory drugs (NSAIDS) are commonly used medications. In the small bowel, NSAIDs may cause a variety of gastrointestinal adverse events including NSAID-induced ulcers. These ulcers are the most important differential diagnosis for small bowel ulcers in patients evaluated for suspected CD. We evaluated a DL network that was trained using CD VCE ulcer images and evaluated its performance for NSAID ulcers. Patients and Methods: The network was trained using CD ulcers and normal mucosa from a large image bank created from VCE of diagnosed CD patients. NSAIDs-induced enteropathy images were extracted from the prospective Bifidobacterium breve (BIf95) trial dataset. All images were acquired from studies performed using PillCam SBIII. The area under the receiver operating curve (AUC) was used as a metric. We compared the network's AUC for detecting NSAID ulcers to that of detecting CD ulcers. Results: Overall, the CD training dataset included 17,640 CE images. The NSAIDs testing dataset included 1,605 CE images. The DL network exhibited an AUC of 0.97 (95% CI 0.97-0.98) for identifying images with NSAID mucosal ulcers. The diagnostic accuracy was similar to that obtained for CD related ulcers (AUC 0.94-0.99). Conclusions: A network trained on VCE CD ulcers similarly identified NSAID findings. As deep learning is transforming gastrointestinal endoscopy, this result should be taken into consideration in the future design and analysis of VCE deep learning applications.

TNF-Alpha Blockers in Inflammatory Bowel Diseases: Practical Recommendations and a User's Guide: An Update

BACKGROUND

Anti-tumour necrosis factor-alpha (anti-TNF) antagonists have been the mainstay in the treatment of inflammatory bowel diseases (IBDs) for over 20 years.

SUMMARY

This review article aimed to provide an update on recent advances in TNF antagonist therapy for IBDs. Key Messages: Their position in the treatment algorithm has evolved to "rapid step-up therapy" or "top-down therapy" according to disease severity and patients' characteristics. Limitations of anti-TNF antagonists include loss of response in up to 30-50% of patients with or without the development of antibodies. Therapeutic drug monitoring should provide a tailored, personalized approach to this scenario. Recently, biosimilar agents have been approved for IBDs and are considered equivalent in efficacy to the originator.

Randomized Controlled Trial: Subcutaneous vs Intravenous Infliximab CT-P13 Maintenance in Inflammatory Bowel Disease

BACKGROUND & AIMS

This study compared pharmacokinetics, symptomatic and endoscopic efficacy, safety, and immunogenicity of a subcutaneous formulation of the infliximab biosimilar CT-P13 (CT-P13 SC) vs intravenous CT-P13 (CT-P13 IV) in patients with inflammatory bowel disease (IBD).

METHODS

This randomized, multicenter, open-label, parallel-group, phase 1 study enrolled tumor necrosis factor inhibitor-naïve patients with active ulcerative colitis (total Mayo score 6-12 points with endoscopic subscore ≥2) or Crohn's disease (Crohn's Disease Activity Index 220-450 points) at 50 centers. After CT-P13 IV induction at Week (W) 0/W2, patients were randomized (1:1) to receive CT-P13 SC every 2 weeks (q2w) from W6 to W54 or CT-P13 IV every 8 weeks from W6 to W22. At W30, all patients receiving CT-P13 IV switched to CT-P13 SC q2w until W54. The primary endpoint was noninferiority of CT-P13 SC to CT-P13 IV for observed predose CT-P13 concentration at W22 (C_trough,W22), concluded if the lower bound of the 2-sided 90% confidence interval (CI) for the ratio of geometric least-squares means exceeded 80%.

RESULTS

Overall, 66 and 65 patients were randomized to CT-P13 SC and CT-P13 IV, respectively. The primary endpoint of noninferiority was met with a geometric least-squares means ratio for C_trough,W22 of 1154.17% (90% CI 786.37-1694.00; n = 59 [CT-P13 SC]; n = 57 [CT-P13 IV]). W30/W54 clinical remission rates were comparable between arms. Other efficacy, safety, and immunogenicity assessments were also broadly comparable between arms, including after switching.

CONCLUSIONS

The pharmacokinetic noninferiority of CT-P13 SC to CT-P13 IV, and the comparable efficacy, safety, and immunogenicity profiles, support the potential suitability of CT-P13 SC treatment in IBD. ClinicalTrials.gov ID: NCT02883452.

Automated Detection of Crohn's Disease Intestinal Strictures on Capsule Endoscopy Images Using Deep Neural Networks

BACKGROUND AND AIMS

Passable intestinal strictures are frequently detected on capsule endoscopy [CE]. Such strictures are a major component of inflammatory scores. Deep neural network technology for CE is emerging. However, the ability of deep neural networks to identify intestinal strictures on CE images of Crohn's disease [CD] patients has not yet been evaluated.

METHODS

We tested a state-of-the-art deep learning network for detecting CE images of strictures. Images of normal mucosa, mucosal ulcers, and strictures of Crohn's disease patients were retrieved from our previously described CE image bank. Ulcers were classified as per degree of severity. We performed 10 cross-validation experiments. A clear patient-level separation was maintained between training and testing sets.

RESULTS

Overall, the entire dataset included 27 892 CE images: 1942 stricture images, 14 266 normal mucosa images, and 11 684 ulcer images [mild: 7075, moderate: 2386, severe: 2223]. For classifying strictures versus non-strictures, the network exhibited an average accuracy of 93.5% [±6.7%]. The network achieved excellent differentiation between strictures and normal mucosa (area under the curve [AUC] 0.989), strictures and all ulcers [AUC 0.942], and between strictures and different grades of ulcers [for mild, moderate, and severe ulcers-AUCs 0.992, 0.975, and 0.889, respectively].

CONCLUSIONS

Deep neural networks are highly accurate in the detection of strictures on CE images in Crohn's disease. The network can accurately separate strictures from ulcers across the severity range. The current accuracy for the detection of ulcers and strictures by deep neural networks may allow for automated detection and grading of Crohn's disease-related findings on CE.

Evolution of Inflammatory Bowel Disease Research From a Bird's-Eye Perspective: A Text-Mining Analysis of Publication Trends and Topics

BACKGROUND AND AIM

Inflammatory bowel disease (IBD) research is extensive and increasing, with topics varying and shifting foci over time. A comprehensive analysis of the trends in IBD publications may help us grasp knowledge gaps and map future areas of interest. The aim of our study was to create a map of IBD research for the last 25 years using computational text-mining techniques.

METHODS

We retrieved all available MEDLINE/PubMed annual datasets between 1992 and 2016. We categorized article characteristics by using word combination and title match techniques. We also assigned country of origin for each article from the first author's affiliation.

RESULTS

During the study period, 18,653 publications that appeared on PubMed were classified as IBD-related. The annual number of publications increased almost 4-fold (354 to 1361) during the study period. The United States had the highest total number of publications (n = 3179/16,358, 19.4%) and Denmark, Sweden, and Israel had the highest rate of publications per capita. There were 7986 articles successfully assigned with a main subject. Therapeutics, surgical treatment, and endoscopy were the 3 leading topics, with n = 2432/7986 (30%), 1707/7986 (21%), and 981/7986 (12%), respectively. When analyzing trends in topics over time, we found an increase in the proportion of articles on imaging (2.2% in 1992-1996 to 8% in 2012-2016) and a decrease in the proportion of articles on surgical treatment (30% in 1992-1996 to 19% in 2012-2016).

CONCLUSIONS

There is steady increase in the number of IBD-related publications. Although the United States is a world leader in the number of IBD publications, Denmark, Sweden, and Israel publish the most per population size. Medical therapeutics is the most popular topic, yet there is a steady increase in publications devoted to imaging and monitoring.

Infliximab clearance decreases in the second and third trimesters of pregnancy in inflammatory bowel disease

BACKGROUND

Infliximab therapy during pregnancy in inflammatory bowel disease is challenged by a dilemma between maintaining adequate maternal disease control while minimizing fetal infliximab exposure. We investigated the effects of pregnancy on infliximab pharmacokinetics.

METHODS

The study population comprised 23 retrospectively identified pregnancies. Patients with inflammatory bowel disease were generally in clinical remission at pregnancy conception (74%) and received steady infliximab maintenance therapy (5 mg/kg q8w n = 17; q6w n = 4; q10w n = 1; 10 mg/kg q8w n = 1). Trough blood samples had been obtained in the same patients prior to pregnancy (n = 119), the first trimester (n = 16), second trimester (n = 18), third trimester (n = 7), and postpregnancy (n = 12). Data were analyzed using nonlinear mixed-effects population pharmacokinetic modeling.

RESULTS

Dose-normalized infliximab concentrations were significantly higher during the second trimester (median 15 mg/ml/kg, interquartile range 10-21) compared to prepregnancy (7, 2-12; p = 0.003), the first trimester (9, 1-12; p = 0.04), or postpregnancy (6, interquartile range 3-11; p > 0.05) in patients with inflammatory bowel disease. Similar trends were observed in the third trimester (13, 7-36; p > 0.05). A one-compartment model with linear elimination described the pharmacokinetics of infliximab (volume of distribution n = 18.2 L; clearance 0.61 L/day). Maternal infliximab exposure was influenced by the second and third trimester of pregnancy and anti-infliximab antibodies, and not by pregnancy-imposed physiological changes in, for example, body weight or albumin. Infliximab clearance decreased significantly during the second and third trimesters by up to 15% as compared to pre- and postpregnancy and the first trimester. The increased maternal infliximab exposure was weakly associated with lowered clinical disease activity. Pharmacokinetic model simulations of virtual patients indicated the increased maternal infliximab trough concentrations imposed by pregnancy will not completely counteract the decrease in infliximab concentration if therapy is paused in the third trimester.

CONCLUSION

Infliximab clearance decreases significantly in the second and third trimesters, leading to increasing maternal infliximab concentrations in any given regimen. Maternal infliximab levels may thus be maintained as constant in a de-intensified regimen by therapeutic drug monitoring guidance in inflammatory bowel disease.

Barriers to international travel in inflammatory bowel disease patients

BACKGROUND

Inflammatory bowel disease poses substantial challenges to travel. We aimed to investigate inflammatory bowel diseases (IBD)-associated challenges to travel, information-seeking behaviour and associated factors.

METHODS

We collected data on patients' demographics, disease characteristics, travel barriers, information-seeking behaviour and travel outcomes in UK, Australia, New Zealand and Israel (2016-2018). Summary statistics were used to describe the sample, whereas multivariate binary and nominal logistic regression were used to model the outcome variables.

RESULTS

Almost 75.4% (1878/2491) participants' data were analysed with 71.14%, 15.4%, 11.2% and 2.1% from UK, Australia, NZ and Israel, respectively (76.3% females, 48.2% 30-49 years old 58.8% Crohn's disease). About 7.7% of study participants sought medical advice/were hospitalised while overseas. About 43.8% cancelled/changed their plans due to IBD. The most common barriers were worry about toilet facilities (76.3%), cleanliness/sanitation (50.9%) and availability of medical care (41.1%). Only 60.5% sought travel advice; the most popular information source was IBD doctor/nurse (32.6%). Almost 32.6% of study participants did not get travel insurance that covered their IBD. Those who did not receive advice or found obtaining travel insurance difficult, were less likely to obtain travel insurance (P < 0.001). Participants who travelled for work were more likely to be hospitalised/seek medical advice overseas and not obtain travel insurance.

CONCLUSIONS

We report a detailed investigation on the IBD-associated barriers while travelling abroad, common information-seeking behaviours and factors associated with worse outcomes. Importantly, patients from all the surveyed countries provided similar travel barrier and preparation habits, highlighting the consistent nature of the challenge.

Ulcer severity grading in video capsule images of patients with Crohn's disease: an ordinal neural network solution

BACKGROUND AND AIMS

Capsule endoscopy (CE) is an important modality for diagnosis and follow-up of Crohn's disease (CD). The severity of ulcers at endoscopy is significant for predicting the course of CD. Deep learning has been proven accurate in detecting ulcers on CE. However, endoscopic classification of ulcers by deep learning has not been attempted. The aim of our study was to develop a deep learning algorithm for automated grading of CD ulcers on CE.

METHODS

We retrospectively collected CE images of CD ulcers from our CE database. In experiment 1, the severity of each ulcer was graded by 2 capsule readers based on the PillCam CD classification (grades 1-3 from mild to severe), and the inter-reader variability was evaluated. In experiment 2, a consensus reading by 3 capsule readers was used to train an ordinal convolutional neural network (CNN) to automatically grade images of ulcers, and the resulting algorithm was tested against the consensus reading. A pretraining stage included training the network on images of normal mucosa and ulcerated mucosa.

RESULTS

Overall, our dataset included 17,640 CE images from 49 patients; 7391 images with mucosal ulcers and 10,249 normal images. A total of 2598 randomly selected pathologic images were further graded from 1 to 3 according to ulcer severity in the 2 different experiments. In experiment 1, overall inter-reader agreement occurred for 31% of the images (345 of 1108) and 76% (752 of 989) for distinction of grades 1 and 3. In experiment 2, the algorithm was trained on 1242 images. It achieved an overall agreement for consensus reading of 67% (166 of 248) and 91% (158 of 173) for distinction of grades 1 and 3. The classification accuracy of the algorithm was 0.91 (95% confidence interval, 0.867-0.954) for grade 1 versus grade 3 ulcers, 0.78 (95% confidence interval, 0.716-0.844) for grade 2 versus grade 3, and 0.624 (95% confidence interval, 0.547-0.701) for grade 1 versus grade 2.

CONCLUSIONS

CNN achieved high accuracy in detecting severe CD ulcerations. CNN-assisted CE readings in patients with CD can potentially facilitate and improve diagnosis and monitoring in these patients.

Novel bio-genetic predictors of response to biologic treatment in inflammatory bowel diseases

Despite the evolving therapeutic armamentarium, the treatment of IBD patients remains challenging and many patients fail to respond to biologic agents. With the limited yield of clinical factors to predict the outcome of biologic treatments, studies have focused on identifying genetic alterations and circulating or tissue biomarkers to identify patients who are likely to respond to therapy. In this review, we examine the current knowledge and status of genetic, expression biomarkers, and microbiome predictors. The search for genetic predictors has yielded many genetic loci variants, but few were reproducible. Expression studies of putative biomarkers show promising results, especially with TREM1, oncostatin M and TNF biomarkers, but confirmatory studies are warranted. Finally, the microbiome is emerging as an important player with specific taxa and functional pathways differentially abundant and enriched in responders versus non-responders to certain biologics. Integrating different factors into a robust predictive model, which is both reproducible, accurate and affordable, remains the main challenge before these individualized strategies can reach clinical use.

Prediction of Recurrent Emergency Department Visits among Patients with Crohn's Disease: A Retrospective Study

Patients with Crohn’s disease (CD) are frequently subject to symptoms causing them to seek medical care in emergency departments (ED). Recurrent ED visits are frequent after initial discharge. We aimed to identify the characteristics of patients with Crohn’s who tend to have recurrent visits to the ED. We created an electronic data repository of all patients with inflammatory bowel diseases who visited the ED in our tertiary medical center during the period 2012–2018. For this study, we retrieved consecutive Crohn’s patients who presented with CD-related symptoms to the ED and were eventually discharged. Patients who returned to the ED in 7 and 30 days were compared with those who did not. Overall, 2299 patients visited our ED with complaints related to Crohn’s disease exacerbation or complication. A total of 1259 (60% of the adult patients) were admitted for hospitalization. Of the 632 (33%) who were discharged from the ED, 53 (8.4%) and 110 (17.4%) re-visited the ED, in 7 and 30 days from discharge, respectively. In multivariable analysis, tachycardia (odds ratio (OR) = 2.19, 95% confidence interval (CI): 1.11–4.33, p value = 0.02), elevated alkaline phosphatase (OR = 2.09, 95% CI: 1.07–4.07, p value = 0.02), and hyponatremia (OR = 2.52, 95% CI: 1.24–5.10, p value = 0.01) were associated with revisiting the ED within 7 days. Tachycardia (OR 2.88 (95% CI 1.33–6.2)), anemia (OR 2.44 (95% CI 1.24–4.8)), and elevated alkaline phosphatase (OR 2.68 (95% CI 1.25–5.78)) were independently associated with ED returns in 30 days. Knowing these risk factors may assist in minimizing the burden of recurrent ED visits among patients with CD.

Combination Therapy of Adalimumab With an Immunomodulator Is Not More Effective Than Adalimumab Monotherapy in Children With Crohn's Disease: A Post Hoc Analysis of the PAILOT Randomized Controlled Trial

BACKGROUND

The PAILOT trial was a randomized controlled trial aimed to evaluate proactive vs reactive therapeutic drug monitoring in children with Crohn's disease (CD) treated with adalimumab. Our aim in this post hoc analysis of the PAILOT trial was to assess the efficacy and safety of adalimumab combination treatment in comparison with monotherapy at week 72 after adalimumab induction.

METHODS

Participants were children 6-17 years old, biologic naïve, with moderate to severe CD, who responded to adalimumab induction at week 4. Patients receiving immunomodulators at baseline maintained a stable dose until week 24; patients could then discontinue immunomodulators. At each visit, patients were assessed for disease index, serum biomarkers, fecal calprotectin, adalimumab trough concentration, and anti-adalimumab antibodies.

RESULTS

Out of the 78 patients (29% female; mean age, 14.3 ± 2.6 years), 34 patients (44%) received combination therapy. During the study period, there was no significant difference in the rates of sustained corticosteroid-free clinical remission (25/34, 73%, vs 28/44, 63%; P = 0.35) or sustained composite outcome of clinical remission, C-reactive protein ≤0.5 mg/dL, and calprotectin ≤150 µg/g (10/34, 29%, vs 14/44, 32%; P = 0.77) between the combination group and the monotherapy group, respectively. Clinical and biological outcomes did not differ between the proactive and reactive subgroups within the combination and monotherapy groups. Adalimumab trough concentrations and immunogenicity were not significantly different between groups. The rate of serious adverse events was not significantly different between groups but was numerically higher in the monotherapy group.

CONCLUSIONS

Combination therapy of adalimumab and an immunomodulator was not more effective than adalimumab monotherapy in children with CD (ClinicalTrials.gov No. NCT02256462).

Terminal Ileum Thickness During Maintenance Therapy Is a Predictive Marker of the Outcome of Infliximab Therapy in Crohn Disease

BACKGROUND

Mucosal healing has been associated with long-term response to therapy for Crohn disease (CD). However, little is known about the significance of terminal ileum (TI) transmural thickness in predicting clinical outcomes.

METHODS

In this retrospective observational cohort study, we examined the association of an index ultrasonographic assessment of TI thickness during the maintenance phase and the subsequent clinical outcome of CD in a cohort of patients treated with infliximab (IFX). Treatment failure was defined as treatment discontinuation because of lack of efficacy, a need for dose escalation, or surgery. Clinical response was defined as treatment continuation in the absence of any of the aforementioned failure criteria.

RESULTS

Sixty patients with CD receiving IFX therapy were included in the study. The patients were followed for a median of 16 months (5-24 months) after an index intestinal ultrasound. Thirty-eight patients (63.3%) maintained response to the therapy and 22 patients (36.6%) failed the treatment, with a mean follow up of 10.5 months (6.5-17 months) vs 9.25 months (1-10.25 months), respectively. On univariate analysis, the only variables differing between treatment response and failure were a TI thickness of 2.8 vs 5 mm (P < 0.0001) and an IFX trough level of 6.6 vs 3.9 µg/mL (P = 0.008).On multivariable analysis, only a small bowel thickness of ≥4 mm was associated with the risk of treatment failure (odds ratio, 2.9; 95% CI, 1.49-5.55; P = 0.002).

CONCLUSIONS

Our findings suggest that transmural thickness of ≥4 mm can predict subsequent treatment failure in patients with CD treated using IFX, indicating transmural thickness <4 mm as a potential novel valuable therapeutic target.