Fecal Calprotectin as Predictor of Relapse in Patients With Inflammatory Bowel Disease Under Maintenance Infliximab Therapy

The Influence of Subclinical Active Inflammation on IFX Pharmacokinetic Modeling and Disease Progression Assessment: Findings from a Prospective Real-World Study in Inflammatory Bowel Disease Patients

BACKGROUND AND AIMS

Effective management of inflammatory bowel disease (IBD) relies on a comprehensive understanding of infliximab (IFX) pharmacokinetics (PK). This study's primary goal was to develop a robust PK model, identifying key covariates influencing IFX clearance (CL), while concurrently evaluating the risk of disease progression during the maintenance phase of IBD treatment.

METHODS

The multicenter, prospective, real-world DIRECT study was conducted in several care centers, which included 369 IBD patients in the maintenance phase of IFX therapy. A two-compartment population PK model was used to determine IFX CL and covariates. Logistic and Cox regressions were applied to elucidate the associations between disease progression and covariates embedded in the PK model.

RESULTS

The PK model included the contributions of weight, albumin, antidrug antibody (ADA), and fecal calprotectin (FC). On average, higher ADA, FC concentration and weight, and lower albumin concentration resulted in higher IFX CL. In the multivariate regression analyses, FC levels influenced the odds of disease progression in the majority of its definitions, when adjusted for several confounding factors. Additionally, alongside FC, both IFX and CL demonstrated a significant impact on the temporal aspect of disease progression.

CONCLUSION

In this 2-year real-world study, readily available clinical covariates, notably FC, significantly impacted IFX availability in IBD patients. We demonstrated that subclinical active inflammation, as mirrored by FC or CRP, substantially influenced IFX clearance. Importantly, FC emerged as a pivotal determinant, not only of IFX pharmacokinetics but also of disease progression. These findings underscore the need to integrate FC into forthcoming IFX pharmacokinetic models, amplifying its clinical significance.

The role of fecal biomarkers in individuals with inflammatory bowel disease

INTRODUCTION

Inflammatory bowel disease (IBD), encompassing Crohn's disease (CD) and Ulcerative Colitis (UC), is a relapsing and remitting condition. Noninvasive biomarkers have an increasingly important role in the diagnosis of IBD and in the prediction of future disease course in individuals with IBD. Strategies for the management of IBD increasingly rely upon close monitoring of gastrointestinal inflammation.

AREAS COVERED

This review provides an update on the current understanding of established and novel stool-based biomarkers in the diagnosis and management of IBD. It also highlights key gaps, identifies limitations, and advantages of current markers, and examines aspects that require further study and analysis.

EXPERT OPINION

Current noninvasive inflammatory markers play an important role in the diagnosis and management of IBD; however, limitations exist. Future work is required to further characterize and validate current and novel markers of inflammation. In addition, it is essential to better understand the roles and characteristics of noninvasive markers to enable the appropriate selection to accurately determine the condition of the intestinal mucosa.

Diagnostic Accuracy of Fecal Calprotectin for Predicting Relapse in Inflammatory Bowel Disease: A Meta-Analysis

Fecal calprotectin (FC) levels correlate with the disease activity of inflammatory bowel diseases (IBD); however, the utility of FC in predicting IBD relapse remains to be determined. We aim to evaluate the efficacy of fecal calprotectin in predicting the relapse of inflammatory bowel disease. We searched Pubmed (MEDLINE), Embase, Web of Science, and the Cochrane library databases up to 7 July 2021. Our study estimated the pooled sensitivity and specificity, summary receiver operating characteristic (SROC) curve, and the optimal cut-off value for predicting IBD relapse using a multiple threshold model. A total of 24 prospective studies were included in the meta-analysis. The optimal FC cut-off value was 152 μg/g. The pooled sensitivity and specificity of FC was 0.720 (0.528 to 0.856) and 0.740 (0.618 to 0.834), respectively. FC is a useful, non-invasive, and inexpensive biomarker for the early prediction of IBD relapse. An FC value of 152 μg/g is an ideal threshold to identify patients with a high relapse probability.

Improved comprehensive evaluation of Crohn's disease activity by intestinal computed tomography enterography combined with endoscopy and biochemical indicators

BACKGROUND AND STUDY AIMS

The treatment approach for Crohn's disease (CD) is focused on mucosal healing and resolution of transmural inflammation. The aim of this study is to evaluate the correlation between computed tomography enterography (CTE) and other treatments, in particular, endoscopy and biochemical indicators, in newly diagnosed patients with CD.

PATIENTS AND METHODS

One hundred twenty-three patients with CD who received CTE in Xiangya Hospital, Central South University, China, from April 2017 to April 2019 were included. The clinical case data and imaging results were retrospectively reviewed. The clinical activity of CD was determined by the Crohn's disease activity index (CDAI) score and biochemical indicators. The relationships between CTE and endoscopy, CDAI score, and inflammatory markers were evaluated.

RESULTS

The diagnostic rate of CTE of the 123CD patients was 68.3% (84/123). Logistic regression analysis showed that the specific CTE manifestations related to CD activity were intestinal wall stratification, comb sign, and abdominal abscesses (P < 0.05). Spearman's rank correlation analysis showed that inflammatory markers positively correlated with different CTE imaging manifestations.

CONCLUSION

Intestinal CTE combined with endoscopy and biochemical indicators is both comprehensive and effective in evaluating the condition of CD patients.

Increased monocyte abundance as a marker for relapse after discontinuation of biologics in inflammatory bowel disease with deep remission

Monocytes are involved in the upstream inflammatory process in the immune reaction in inflammatory bowel disease (IBD). Patients with IBD who discontinued biologics have been found to relapse, even after checking for deep remission. This study investigated whether monocytes could act as a predictor of relapse in patients who experienced relapse after the discontinuation of biologics. To this end, pediatric patients (<19 years old, n = 727) diagnosed with IBD from January 2003 to December 2021 were retrospectively reviewed. Clinical features, monocytes, and disease activity at the time of discontinuing biologics were evaluated by dividing patients into a relapsed group and a non-relapsed group after discontinuing biologics. The percentage of monocytes (8.65% vs. 6.42%, P < 0.001), the absolute monocyte count (614.79 cells/μL vs. 381.70 cells/μL, P < 0.001), and the monocyte/polymorphonuclear leukocyte (PMN) ratio (0.18 vs. 0.11, P < 0.001) at the time of discontinuation were significantly higher in patients who experienced relapse. As a result of multivariate analysis, the monocyte percentage (odds ratio: 2.012, P < 0.001) and monocyte/PMN ratio (odds ratio: 4.320E+14, P = 0.002) were evaluated as risk factors for relapse. Diagnostic capability was confirmed using area under operating characteristic curve (0.782) of the monocyte percentage for assessing the relapse within 6 months with cutoff value of 8.15% (P < 0.001). The findings presented in this study indicate that the patients with high monocyte counts experienced relapse after the discontinuation of biologics. A monocyte percentage of over 8.15% in the blood at the time of discontinuation was found to be associated with a high probability of relapse within 6 months, even in deep remission.

Endoscopy for assessment of mucosal healing in ulcerative colitis: time bound or response guided?

The timing of colonoscopy in patients with active ulcerative colitis (UC) lacks coherence. The published guidelines and recommendations advocate time-bound colonoscopy in patients with active UC to assess for mucosal healing. However, the practice of performing colonoscopies at fixed time frames lacks reasoning. The time to achieve mucosal healing in UC is not uniform across the patient populations and is influenced by the disease severity and efficacy and time to therapeutic response of the drugs being used. Additionally, with the availability of sensitive noninvasive inflammatory biomarkers such as fecal calprotectin, that parallel the disease activity and correlate with mucosal healing, the notion of performing colonoscopy at fixed intervals sounds unjustifiable. The authors express their view that a response-guided colonoscopy (driven by normalization of clinical symptoms and inflammatory biomarkers), rather than a time-bound colonoscopy, would be more logical, apart from being cost-effective and patient-friendly.

Relative Contribution of Disease Activity and Psychological Health to Prognosis of Inflammatory Bowel Disease During 6.5 Years of Longitudinal Follow-Up

BACKGROUND & AIMS

Symptoms of common mental disorders, such as anxiety or depression, are common in inflammatory bowel disease (IBD) and may affect prognosis. However, unlike clinical or biochemical markers of disease activity, psychological health is not a recommended therapeutic target. We assessed relative contribution of poor psychological health and clinical or biochemical activity to prognosis.

METHODS

Demographic features, IBD subtype, treatments, and anxiety and depression scores were recorded at baseline for 760 adults, with clinical activity determined using validated scoring systems. Fecal calprotectin was analyzed in 379 (49.9%) patients (≥250 μg/g used to define biochemical activity). Glucocorticosteroid prescription or flare, escalation, hospitalization, intestinal resection, or death were assessed during 6.5 years of follow-up. Occurrence was compared using multivariate Cox regression across 4 patient groups according to presence of disease remission or activity, with or without symptoms of a common mental disorder, at baseline.

RESULTS

In total, 718 (94.5%) participants provided data. Compared with clinical remission without symptoms of a common mental disorder at baseline, need for glucocorticosteroid prescription or flare (hazard ratio [HR], 2.36; 95% confidence interval [CI], 1.58-3.54), escalation (HR, 1.65; 95% CI, 1.14--2.40), and death (HR, 4.99; 95% CI, 1.80-13.88) were significantly higher in those with clinical activity and symptoms of a common mental disorder. Rates in those with clinical remission and symptoms of a common mental disorder at baseline or those with clinical activity without symptoms of a common mental disorder were not significantly higher. Similarly, with biochemical activity and symptoms of a common mental disorder, rates of glucocorticosteroid prescription or flare (HR, 2.48; 95% CI, 1.38-4.46), escalation (HR, 2.97; 95% CI, 1.74-5.06), hospitalization (HR, 3.10; 95% CI, 1.43-6.68), and death (HR, 6.26; 95% CI, 2.23-17.56) were significantly higher.

CONCLUSIONS

Psychological factors are important determinants of poor prognostic outcomes in IBD and should be considered as a therapeutic target.

N-Formyl Methionine Peptide-Mediated Neutrophil Activation in Systemic Sclerosis

Exaggerated neutrophil activation and formation of neutrophil extracellular traps (NETs) are reported in systemic sclerosis (SSc) but its involvement in SSc pathogenesis is not clear. In the present study we assessed markers of neutrophil activation and NET formation in SSc patients in relation to markers of inflammation and disease phenotype. Factors promoting neutrophil activation in SSc remain largely unknown. Among the neutrophil activating factors, mitochondrial-derived N-formyl methionine (fMet) has been reported in several autoinflammatory conditions. The aim of the current study is to assess whether SSc patients have elevated levels of fMet and the role of fMet in neutrophil-mediated inflammation on SSc pathogenesis. Markers of neutrophil activation (calprotectin, NETs) and levels of fMet were analyzed in plasma from two SSc cohorts (n=80 and n=20, respectively) using ELISA. Neutrophil activation assays were performed in presence or absence of formyl peptide receptor 1 (FPR1) inhibitor cyclosporin H. Elevated levels of calprotectin and NETs were observed in SSc patients as compared to healthy controls (p<0.0001) associating with SSc clinical disease characteristics. Further, SSc patients had elevated levels of circulating fMet as compared to healthy controls (p<0.0001). Consistent with a role for fMet-mediated neutrophil activation, fMet levels correlated with levels of calprotectin and NETs (r=0.34, p=0.002; r=0.29, p<0.01 respectively). Additionally, plasma samples from SSc patients with high levels of fMet induced de novo neutrophil activation through FPR1-dependent mechanisms. Our data for the first time implicates an important role for the mitochondrial component fMet in promoting neutrophil-mediated inflammation in SSc.

Combined Use of Fecal Biomarkers in Inflammatory Bowel Diseases: Oncostatin M and Calprotectin

Background

Fecal biomarkers have emerged as one of the most useful tools for clinical management of inflammatory bowel disease (IBD). Oncostatin M (OSM), like fecal calprotectin (FC), is highly expressed in the inflamed intestinal mucosa which may have potential usefulness. We aimed to evaluate the additional utility of these two fecal biomarkers for IBD diagnosis, activity, and prediction of infliximab response over FC alone.

Methods

In group 1, 236 IBD patients (145 Crohn’s disease, 91 ulcerative colitis), 50 disease controls, and 32 healthy controls were recruited for IBD diagnosis and activity. In group 2, baseline stool samples were collected from 62 patients to predict infliximab response at week 28 and 52. The performance of fecal biomarkers for IBD management was assessed by the area under the receiver operating characteristic curve (AUC).

Results

Fecal OSM and FC levels were increased in IBD patients and were positively correlated with clinical and endoscopic activity. Their combination showed a better ability for disease diagnosis (AUC = 0.93) and slightly improved the capability to identify mucosal healing (AUC = 0.923). Baseline OSM and FC levels were elevated in non-responders at week 28 and 52. The AUCs of OSM, FC, and their combination to predict therapeutic response were 0.763, 0.834, and 0.859 at week 28, 0.638, 0.661, and 0.704 at week 52, respectively. Combined use of fecal and blood biomarkers improved predictive accuracy with an AUC of 0.919 at week 28 and 0.887 at week 52.

Conclusion

In addition to FC, OSM is a novel fecal biomarker, and their combination is more beneficial for disease diagnosis and prediction of infliximab response but not for disease activity in IBD patients. Further larger-scale studies are required to confirm our findings.

Proactive therapeutic drug monitoring is more effective than conventional management in inducing fecal calprotectin remission in inflammatory bowel disease

BACKGROUND

Proactive therapeutic drug monitoring (pTDM) may improve treatment outcomes in inflammatory bowel disease.

AIMS AND METHODS

We compared 135 patients following a prospective pTDM protocol aiming at an infliximab trough level (IFXTL) between 5 and 10 μg/ml with sequential measurements of Fc, with 108 patients from a retrospective group under conventional management. We evaluated the rates of Fc remission (<250 μg/g) and other clinical outcomes at 2-year of follow-up.

RESULTS

pTDM associated with higher rates of Fc remission (69.6% vs. 50.0%; P = 0.002), and steroid-free clinical remission (78.4% vs. 55.2%, P = 0.028) with a trend for clinical remission (79.3% vs. 68.5%, P = 0.075). There was no difference in treatment discontinuation (P = 0.195), hospitalization (P = 0.156), and surgery (P = 0.110). Higher IFXTL associated with Fc remission at week 14 (6.59 vs. 2.96 μg/ml, P < 0.001), and at the end of follow-up (8.10 vs. 5.03 μg/ml, P = 0.001). In patients reaching Fc remission after week 14, IFXTL increased from week 14 to the end of follow-up (2.71 vs. 8.54 μg/ml, P < 0.001). Fc remission associated with higher rates of clinical (85.8% vs. 56.8% P < 0.001) and steroid-free clinical remission (86.9% vs. 50.0% P < 0.001), lower IFX discontinuation (8.8% vs. 36.8%, P < 0.001), and hospitalization (13.5% vs. 33.7%, P < 0.001), without significance for surgery (6.1% vs. 12.6%, P = 0.101).

CONCLUSION

pTDM was more effective than conventional management in inducing Fc remission which was associated with improved outcomes.

Treatment Targets in Ulcerative Colitis: Is It Time for All In, including Histology?

The main therapeutic goal of ulcerative colitis (UC) is to induce and maintain remission to prevent long-term disease progression. Treat-to-target strategies, first introduced by the STRIDE consensus and updated in 2021, have shifted focus from symptomatic control toward more stringent objective endpoints. Today, patient monitoring should be based on a combination of biomarkers and clinical scores, while patient-reported outcomes could be used as short-term targets in monitoring disease activity and therapeutic response. In addition, endoscopic healing was the preferred long-term goal in UC. A Mayo endoscopic score (MES) ≤ 1 can be recommended as a minimum target. However, recent evidence suggests that more stringent endoscopic goals (MES of 0) are associated with superior outcomes. Recently, emerging data support that histological remission (HR) is a superior prognostic factor to endoscopic healing in predicting long-term remission. Despite not yet being recommended as a target, HR may become an important potential therapeutic goal in UC. However, it remains questionable if histological healing should be used as a routine assessment in addition to clinical, biomarker, and endoscopic targets in all patients. Therefore, in this review, our aim was to discuss the current evidence for the different treatment targets and their value in everyday clinical practice.

Antimicrobial peptides and the gut microbiome in inflammatory bowel disease

Antimicrobial peptides (AMP) are highly diverse and dynamic molecules that are expressed by specific intestinal epithelial cells, Paneth cells, as well as immune cells in the gastrointestinal (GI) tract. They play critical roles in maintaining tolerance to gut microbiota and protecting against enteric infections. Given that disruptions in tolerance to commensal microbiota and loss of barrier function play major roles in the pathogenesis of inflammatory bowel disease (IBD) and converge on the function of AMP, the significance of AMP as potential biomarkers and novel therapeutic targets in IBD have been increasingly recognized in recent years. In this frontier article, we discuss the function and mechanisms of AMP in the GI tract, examine the interaction of AMP with the gut microbiome, explore the role of AMP in the pathogenesis of IBD, and review translational applications of AMP in patients with IBD.

Inflammatory bowel disease manifestations in spondyloarthritis: considerations for the clinician

INTRODUCTION

Spondyloarthropathies (SpA) are a group of inflammatory arthritis that can involve the spine and/or peripheral joints. Extra-articular manifestations, such as inflammatory bowel disease (IBD), are frequently observed within the clinical manifestations of SpA and are part of the SpA classification criteria. Evidence of IBD is observed in about 6-7% of SpA patients, and a silent, microscopic gut inflammation, could be present in up to 50% of patients. From a pathogenetic point of view, dysregulated microbiome and migration of T lymphocytes and other cells from gut to the joint ('gut-joint' axis) has been recognized, in the context of a common genetic background.

AREAS COVERED

The aim of this paper is to narratively review the recent evidences on the epidemiology, classification, clinical findings, pathogenesis, diagnosis, and treatment of IBD in patients with SpA and to provide advices for both rheumatologist and gastroenterologist in the management of IBD in SpA.

EXPERT OPINION

IBD manifestations in SpA frequently increase the burden of the disease and represent a clinical challenge, especially for the diagnosis, assessment, and treatment of patients affected by those conditions. New treatment strategies targeting both articular and intestinal manifestations are now available and may lead to a better outcome.

USEFULNESS OF PERIPHERAL BLOOD MONOCYTE COUNT TO PREDICT RELAPSE IN PATIENTS WITH INFLAMMATORY BOWEL DISEASE: A PROSPECTIVE LONGITUDINAL COHORT STUDY

Monocytes play an important role in the pathogenesis of inflammatory bowel disease but data are scarce as a biomarker of activity, above all, in patients under biologic therapies. The aim was to evaluate the value of monocyte measurements in predicting flares in inflammatory bowel disease patients under maintenance treatment with anti-TNF. A prospective, observational cohort study was designed. Relapse was defined as a Harvey-Bradshaw score >4 in Crohn's disease and a partial Mayo score ≥2 in ulcerative colitis. Monocytes concentration was quantified at 4-month intervals for twelve months. 95 consecutive patients were included. The median age was 42 years, 50.5% female and 75% with Crohn's disease. 65 (68.4%) patients remained in clinical remission. Mean monocyte concentration preceding the relapse was 563 (standard deviation 144) compared to 405 (standard deviation 177) in patients who kept in remission. Final monocytes concentration significantly differentiated between relapse and remission in Crohn's disease (AUC 0.82; 95% CI: 0.71-0.90; P <0.005). In the multivariate analysis, only monocytes and fecal calprotectin related to more relapses. In conclusion, in inflammatory bowel disease patients under anti-TNF therapy, repeated monocytes concentration could help in order to monitoring patients, at least, in Crohn's disease.

Global Studies of Using Fecal Biomarkers in Predicting Relapse in Inflammatory Bowel Disease

Inflammatory bowel disease (IBD) is a chronic inflammatory condition of the gastrointestinal tract mainly comprising two forms including Crohn's disease (CD) and ulcerative colitis (UC). IBD is a lifelong relapsing remitting disease and relapses occur at random patterns which are unpredictable. Fecal biomarkers have been increasingly used to assess disease activity in IBD due to their positive correlations with intestinal inflammation. Recent studies have also assessed the use of fecal biomarkers in predicting relapse and post-operative recurrence. This review provides information from global studies of using fecal calprotectin, lactoferrin and S100A12 to predict relapse in IBD. Strategies for further studies and the use of these fecal biomarkers for personalized management in IBD are also discussed.

First United Arab Emirates consensus on diagnosis and management of inflammatory bowel diseases: A 2020 Delphi consensus

Ulcerative colitis and Crohn's disease are the main entities of inflammatory bowel disease characterized by chronic remittent inflammation of the gastrointestinal tract. The incidence and prevalence are on the rise worldwide, and the heterogeneity between patients and within individuals over time is striking. The progressive advance in our understanding of the etiopathogenesis coupled with an unprecedented increase in therapeutic options have changed the management towards evidence-based interventions by clinicians with patients. This guideline was stimulated and supported by the Emirates Gastroenterology and Hepatology Society following a systematic review and a Delphi consensus process that provided evidence- and expert opinion-based recommendations. Comprehensive up-to-date guidance is provided regarding diagnosis, evaluation of disease severity, appropriate and timely use of different investigations, choice of appropriate therapy for induction and remission phase according to disease severity, and management of main complications.

Calprotectin in inflammatory bowel disease

The term IBD is usually used for referring to a group of inflammatory gastro-intestinal diseases (mainly Crohn's disease and ulcerative colitis). Accordingly, IBD arises as a result of inappropriate immune response to intestinal commensal organisms among genetically susceptible individuals. Performing colonoscopy and histopathologic evaluation on an inflamed bowel biopsy specimen are currently considered as gold standards for diagnosis and management of IBD. Correspondingly, these techniques are known to be invasive and costly. In recent decades, fecal calprotectin, as a biomarker, has received much attention for the diagnosis and non-invasive management of IBD. Up to now, many studies have investigated the efficacy of fecal calprotectin in the areas of IBD differentiation from IBS, prediction of endoscopic and histologic activities of IBD and prediction of disease recurrence. Although some of these studies have reported promising results, some others have shown significant limitations. Therefore, in this paper, we reviewed the most interesting ones of these studies after a brief discussion of the laboratory measurement of fecal calprotectin. Moreover, we attempted to provide an answer for the question of whether fecal-calprotectin could be considered as a potential surrogate marker for colonoscopy.

Calprotectin, an available prognostic biomarker in systemic sclerosis: a systematic review

BACKGROUND

Finding easier and less invasive biologic biomarker in the clinical specimen of systemic sclerosis (SSc) patients can be effective in diagnosing and treating SSc-associated multisystem diseases. The complex of S100A8 and S100A9 (Calprotectin) is an easily available prognostic biomarker that secretes from immune cells and is necessary for initiating the immune response to noninfectious inflammation processes. The present study aims to evaluate the effectiveness of Calprotectin in specimen of SSc patients. We reviewed the evidence for Calprotectin in diagnostic and prognostic of SSc patients.

METHODS

This systematic review was done to identify studies on "Calprotectin" within "SSc" patients. PubMed, Web of knowledge, and Scopus were searched for this purpose. A standardized form was used to extract diseases, sample size, biomarkers identified, source of biomarker, and its effects.

RESULTS

Overall, the 16 articles selected show that the main sources of Calprotectin were plasma, bronchoalveolar lavage fluid, and especially stool.

CONCLUSION

The best source of Calprotectin was fecal Calprotectin that could show the inflammation and small intestinal bacterial overgrowth (SIBO) on SSc patients. Also, the most arguable source is plasma because of its low sample size. Comparing the Calprotectin level in different rheumatic diseases showed the specificity of fecal Calprotectin for SSc disease. Nevertheless, it has to be noted that Calprotectin correlates with some other factors such as age, PIP drug, and nonsteroidal anti-inflammatory drugs.

The Safety, Tolerability, and Pharmacokinetics Profile of BT-11, an Oral, Gut-Restricted Lanthionine Synthetase C-Like 2 Agonist Investigational New Drug for Inflammatory Bowel Disease: A Randomized, Double-Blind, Placebo-Controlled Phase I Clinical Trial

BT-11 is a new oral, gut-restricted, first-in-class investigational drug for Crohn disease (CD) and ulcerative colitis (UC) that targets the lanthionine synthetase C-like 2 (LANCL2) pathway and immunometabolic mechanisms. Oral BT-11 was assessed for safety, tolerability, and pharmacokinetics (PK) in normal healthy volunteers (n = 70) in a randomized, double-blind, placebo-controlled trial. Subjects (n = 70) were randomly assigned to one of five single ascending dose cohorts (up to 100 mg/kg, p.o.) and three multiple ascending dose cohorts [up to 100 mg/kg daily (QD) for seven days, orally]. Safety and tolerability were assessed by adverse event (AE) reporting, vital signs, electrocardiogram, hematology, and clinical chemistry. BT-11 did not increase total or gastrointestinal AE rates, as compared with placebo, and no serious adverse events were observed. Oral BT-11 dosing does not result in any clinically significant findings by biochemistry, coagulation, electrocardiogram, hematology, or urinalysis as compared with placebo. Mean fecal concentrations of BT-11 increased linearly with increasing oral doses, with 2.39 mg/g at 7.7 mg/kg on day 7 of the multiple ascending dose (MAD). Analysis of plasma pharmacokinetics indicates that maximum systemic concentrations are approximately 1/6000th of observed concentrations in feces and the distal gastrointestinal tract. Fecal calprotectin levels were lower in BT-11 treated groups as compared to placebo. BT-11 significantly decreases interferon gamma positive (IFNγ+) and tumor necrosis factor alpha positive (TNFα+) cluster of differentiation 4 positive (CD4+) T cells and increases forkhead box P3 positive (FOXP3+) CD4+ T cells in colonic lamina propria mononuclear cells from patients with CD and patients with UC at concentrations of 0.01 µM when treated ex vivo. BT-11 treatment is well-tolerated with no dose-limiting toxicities up to daily oral doses of 100 mg/kg (16 tablets); whereas the efficacious dose is a single tablet (8 mg/kg). Phase II studies in CD and UC patients are ongoing.

The association among enterobacterial flora, dietary factors, and prognosis in patients with ulcerative colitis

The role of enterobacterial flora in the onset and progression of inflammatory bowel diseases is a topic of considerable interest. Here, we assessed the association among enterobacterial flora, dietary factors, and ulcerative colitis (UC) progression. Forty-six patients with UC who were diagnosed as being in remission were enrolled. We collected each patient's stool sample one or two days before diagnostic colonoscopy. After colonoscopy, we observed the patients for one year and then retrospectively divided them into two groups: remission (n = 39) and relapse (n = 7) groups, depending on whether the relapse occurred during the follow-up period, and analyzed the relationship among patient characteristics, dietary factors, enterobacterial flora, and UC relapse. Overall, there were no significant differences in bacterial community populations between the remission and relapse groups, except that the order Lactobacillales was detected at a significantly higher rate in the relapse than in the remission group (100% vs 71.4%, p<0.05). Vitamin C intake was significantly higher in the remission than in the relapse group (p<0.05). Although there were no obvious differences in enterobacterial flora between the remission and relapse groups, there was a relationship among enterobacterial flora, diet, and UC progression. Given that the enterobacterial flora was only analyzed at the initiation of the study, we conclude that in future analyses, enterobacterial flora should be sampled at numerous time points to examine its role in UC progression. Further long-term longitudinal studies examining enterobacterial flora, dietary factors, and UC progression are also required.

Biomarkers in Inflammatory Bowel Disease-Associated Spondyloarthritis: State of the Art and Unmet Needs

Inflammatory bowel disease-associated spondyloarthritis is a systemic disease characterized by the chronic inflammation of both the gastrointestinal tract and the musculoskeletal system. Since inflammatory bowel disease-associated spondyloarthritis has been associated with a significant diagnostic delay, which may lead to poor quality of life and progression of joint damage, efforts to discover new reliable and noninvasive diagnostic biomarkers have been made. We reviewed the state of the art of biomarker research in inflammatory bowel disease-associated spondyloarthritis, showing that to date it has been largely unsatisfactory. Only a few of the biomarkers that have been investigated are likely to enter the clinical practice upon further validation in independent cohorts. The research of new and innovative biomarkers for inflammatory bowel disease-associated spondyloarthritis is warranted.

Pharmacodynamic Monitoring of Biological Therapies in Chronic Inflammatory Diseases

BACKGROUND

Psoriasis, psoriatic arthritis, spondyloarthritis, rheumatoid arthritis, ulcerative colitis, and Crohn disease share similar underlying pathophysiological processes, providing the opportunity to treat the patients using similar biological therapies. Failure of biological treatments due to underexposure can be managed by therapeutic drug monitoring. Adjusting the treatment based on pharmacokinetic monitoring can be further improved by taking pharmacodynamic parameters such as clinical and molecular markers into account.

METHODS

Here, we critically evaluate the existing evidence, the hurdles to be taken, and the opportunities for a widespread implementation of pharmacodynamic monitoring.

RESULTS

Pharmacodynamic monitoring typically is the monitoring of biochemical markers. A pharmacodynamic marker preferably is specific for the pharmacological action of a drug, but most of the time nonspecific pharmacodynamic markers are used, such as C-reactive protein and the erythrocyte sedimentation rate. Clinical pharmacodynamic markers typically evaluate physical variables or symptoms. Although physician-reported outcomes have been studied for a longer time and often have been shown to correlate well with molecular pharmacodynamic markers and treatment outcomes, the introduction of mobile health or mHealth technologies caused a shift toward patient-reported outcomes, with the associated challenge to consistently reflect the inflammatory state, thereby preventing undertreatment or unnecessary overdosing of patients.

CONCLUSIONS

The primary goal of pharmacodynamic monitoring is to optimize the response, but it can also have an impact on safety, costs, patient adherence, etc. Ideally, the constant remote monitoring of patient-reported disease activity is expected to become the standard, facilitated by mHealth technologies.

Systematic Review with Meta-Analysis: Fecal Calprotectin as a Surrogate Marker for Predicting Relapse in Adults with Ulcerative Colitis

The clinical course of ulcerative colitis (UC) is featured by remission and relapse, which remains unpredictable. Recent studies revealed that fecal calprotectin (FC) could predict clinical relapse for UC patients in remission, which has not yet been well accepted. To detect the predictive value of FC for clinical relapse in adult UC patients based on updated literature, we carried out a comprehensive electronic search of PubMed, Web of Science, Embase, and the Cochrane Library to identify all eligible studies. Diagnostic accuracy including pooled sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), diagnostic odds ratio (DOR), and pooled area under the receiver operating characteristic (AUROC) was calculated using a random effects model. Heterogeneity across studies was assessed by the I 2 metric. Sources of heterogeneity were detected using subgroup analysis. Metaregression was used to test potential factors correlated to DOR. Publication bias was assessed using Deek's funnel plots. In our study, 14 articles enrolling a total of 1110 participants were finally included, and all articles underwent a quality assessment. Pooled sensitivity, specificity, PLR, and NLR with 95% confidence intervals (CIs) were 0.75 (95% CI: 0.70-0.79), 0.77 (95% CI: 0.74-0.80), 3.45 (95% CI: 2.31-5.14), and 0.37 (95% CI: 0.28-0.49) respectively. The area under the summary receiver operating characteristic (sROC) curve was 0.82, and the diagnostic odds ratio was 10.54 (95% CI: 6.16-18.02). Our study suggested that FC is useful in predicting clinical relapse for adult UC patients in remission as a simple and noninvasive marker.

Pre-Treatment Biomarkers of Anti-Tumour Necrosis Factor Therapy Response in Crohn's Disease-A Systematic Review and Gene Ontology Analysis

The most prominent treatment for the serious cases of Crohn’s disease (CD) are biological tumour necrosis factor (TNF) inhibitors. Unfortunately, therapy nonresponse is still a serious issue in ~1/3 of CD patients. Accurate prediction of responsiveness prior to therapy start would therefore be of great value. Clinical predictors have, however, proved insufficient. Here, we integrate genomic and expression data on potential pre-treatment biomarkers of anti-TNF nonresponse. We show that there is almost no overlap between genomic (annotated with tissue-specific expression quantitative trait loci data) and transcription (RNA and protein data) biomarkers. Furthermore, using interaction networks we demonstrate there is little direct interaction between the proposed biomarkers, though a majority do have common interactors connecting them into networks. Our gene ontology analysis shows that these networks have roles in apoptotic signalling, response to oxidative stress and inflammation pathways. We conclude that a more systematic approach with genome-wide search of genomic and expression biomarkers in the same patients is needed in future studies.

Consecutive fecal calprotectin measurements for predicting relapse in pediatric Crohn’s disease patients

BACKGROUND

Asymptomatic children with Crohn’s disease (CD) require ongoing monitoring to ensure early recognition of a disease exacerbation.

AIM

In a cohort of pediatric CD patients, we aimed to assess the utility of serial fecal calprotectin measurements to detect intestinal inflammatory activity and predict disease relapse.

METHODS

In this prospective longitudinal cohort study, children with CD on infliximab therapy in clinical remission were included. Fecal calprotectin levels were assessed at baseline and at subsequent 2-5 visits. Clinical and biochemical disease activity were assessed using the Pediatric Crohn’s Disease Activity Index, C-reactive protein and erythrocyte sedimentation rate at baseline and at visits over the following 18 mo.

RESULTS

53 children were included and eighteen patients (34%) had a clinical disease relapse during the study. Baseline fecal calprotectin levels were higher in patients that developed symptomatic relapse [median (interquartile range), relapse 723 μg/g (283-1758) vs 244 μg/g (61-627), P = 0.02]. Fecal calprotectin levels > 250 μg/g demonstrated good predictive accuracy of a clinical flare within 3 mo (area under the receiver operator curve was 0.86, 95% confidence limits 0.781 to 0.937).

CONCLUSION

Routine fecal calprotectin testing in children with CD in clinical remission is useful to predict relapse. Levels > 250 μg/g are a good predictor of relapse in the following 3 mo. This information is important to guide monitoring standards used in this population.

Fecal calprotectin is not superior to serum C-reactive protein or the Harvey-Bradshaw index in predicting postoperative endoscopic recurrence in Crohn's disease

BACKGROUND

Fecal calprotectin (FC) is a widely used noninvasive marker of gut inflammation that is associated with endoscopic severity in Crohn's disease (CD). However, FC has been inconsistent in predicting postoperative recurrence of CD, and its utility in the postoperative setting remains unclear.

MATERIALS AND METHODS

Blood and fecal samples were collected in consecutively recruited patients with CD who had undergone ileocolonic resection and required a colonoscopy to assess postoperative recurrence, as defined by the Rutgeerts score (RS).

RESULTS

A total of 86 patients were prospectively recruited at five centers. Overall, 49 (57%) had CD recurrence (RS≥i2). FC concentrations trended to increase with RS severity; FC median (interquartile range) was significantly higher in patients with endoscopic recurrence than those in endoscopic remission [172.5 (75-375) vs. 75 (36.5-180.5) μg/g, respectively]. The same occurred for C-reactive protein (CRP) [0.5 (0.1-0.95) vs. 0.1 (0.02-0.27)] mg/dl and the Harvey-Bradshaw index (HBI) [4 (2-7) vs. 1 (0-3.5)]. The three variables significantly correlated. The area under the curve to discriminate between patients in endoscopic remission and recurrence was 0.698 for FC, with 62 μg/g being the optimal cut-off point. This indicated FC would have 85.7% sensitivity and 45.9% specificity in detecting any recurrence, having positive predictive value and negative predictive value of 67.7 and 70.8%, respectively. Area under the curve for CRP and HBI were both 0.710. The combination of CRP and HBI provided a positive predictive value 95.7 and a diagnostic odds ratio of 30.8.

CONCLUSION

FC is not better than CRP combined with HBI to predict endoscopic postoperative recurrence of CD.

From bench to bedside: Fecal calprotectin in inflammatory bowel diseases clinical setting

Fecal calprotectin (FC) has emerged as one of the most useful tools for clinical management of inflammatory bowel diseases (IBD). Many different methods of assessment have been developed and different cut-offs have been suggested for different clinical settings. We carried out a comprehensive literature review of the most relevant FC-related topics: the role of FC in discriminating between IBD and irritable bowel syndrome (IBS) and its use in managing IBD patients In patients with intestinal symptoms, due to the high negative predictive value a normal FC level reliably rules out active IBD. In IBD patients a correlation with both mucosal healing and histology was found, and there is increasing evidence that FC assessment can be helpful in monitoring disease activity and response to therapy as well as in predicting relapse, post-operative recurrence or pouchitis. Recently, its use in the context of a treat-to-target approach led to a better outcome than clinically-based therapy adjustment in patients with early Crohn’s disease. In conclusion, FC measurement represents a cheap, safe and reliable test, easy to perform and with a good reproducibility. The main concerns are still related to the choice of the optimal cut-off, both for differentiating IBD from IBS, and for the management of IBD patients.

Management of Paediatric Ulcerative Colitis, Part 1: Ambulatory Care-An Evidence-based Guideline From European Crohn's and Colitis Organization and European Society of Paediatric Gastroenterology, Hepatology and Nutrition

BACKGROUND

The contemporary management of ambulatory ulcerative colitis (UC) continues to be challenging with ∼20% of children needing a colectomy within childhood years. We thus aimed to standardize daily treatment of pediatric UC and inflammatory bowel diseases (IBD)-unclassified through detailed recommendations and practice points.

METHODS

These guidelines are a joint effort of the European Crohn's and Colitis Organization (ECCO) and the Paediatric IBD Porto group of European Society of Paediatric Gastroenterology, Hepatology and Nutrition (ESPGHAN). An extensive literature search with subsequent evidence appraisal using robust methodology was performed before 2 face-to-face meetings. All 40 included recommendations and 86 practice points were endorsed by 43 experts in Paediatric IBD with at least an 88% consensus rate.

RESULTS

These guidelines discuss how to optimize the use of mesalamine (including topical), systemic and locally active steroids, thiopurines and, for more severe disease, biologics. The use of other emerging therapies and the role of surgery are also covered. Algorithms are provided to aid therapeutic decision-making based on clinical assessment and the Paediatric UC Activity Index (PUCAI). Advice on contemporary therapeutic targets incorporating the use of calprotectin and the role of therapeutic drug monitoring are presented, as well as other management considerations around pouchitis, extraintestinal manifestations, nutrition, growth, psychology, and transition. A brief section on disease classification using the PIBD-classes criteria and IBD-unclassified is also part of these guidelines.

CONCLUSIONS

These guidelines provide a guide to clinicians managing children with UC and IBD-unclassified management to provide modern management strategies while maintaining vigilance around appropriate outcomes and safety issues.

Faecal calprotectin level for assessing endoscopic activity and predicting future clinical course in patients with moderately active ulcerative colitis undergoing granulomonocytapheresis: a prospective cohort study

Background

Calprotectin is a stable neutrophil protein, which can be measured in faecal samples. The faecal level of calprotectin increases during disease activity in ulcerative colitis (UC). Nonetheless, the relevance of faecal calprotectin (FC) measurement during granulomonocytapheresis (GMA) for UC has not yet been fully evaluated. This prospective study was to investigate the value of FC for assessing disease activity and predicting clinical course in UC patients undergoing GMA therapy.

Methods

One hundred and eighty-four patients with moderately active UC with endoscopic activity (Mayo endoscopic subscore [MES] = 2 or 3) received Adacolumn GMA therapy (10 apheresis sessions over consecutive 5 weeks). Patients who achieved clinical remission were subsequently given maintenance medications for 12 months. FC levels were measured at entry and after treatment.

Results

After GMA, 80 of the 184 patients (43%) achieved clinical remission, and 51 (28%) achieved mucosal healing (MH; MES = 0 or 1). The median FC level significantly decreased in patients who achieved MH (P = 0.02), but not in those without MH. Thirty-four patients (43%) relapsed during the 12-month follow-up. The median FC level at the end of GMA therapy was significantly higher in patients who subsequently relapsed than in those who maintained remission (149.5 vs 45.5 μg/g, P < 0.001). A cut off value of 114 μg/g had a sensitivity of 76% and a specificity of 85% to predict future relapse.

Conclusions

Our findings indicate that FC is a relevant biomarker, which is convenient to measure for assessing endoscopic activity and predicting relapse in patients who achieve remission following a course of GMA therapy.

ACG Clinical Guideline: Management of Crohn's Disease in Adults

Crohn's disease is an idiopathic inflammatory disorder of unknown etiology with genetic, immunologic, and environmental influences. The incidence of Crohn's disease has steadily increased over the past several decades. The diagnosis and treatment of patients with Crohn's disease has evolved since the last practice guideline was published. These guidelines represent the official practice recommendations of the American College of Gastroenterology and were developed under the auspices of the Practice Parameters Committee for the management of adult patients with Crohn's disease. These guidelines are established for clinical practice with the intent of suggesting preferable approaches to particular medical problems as established by interpretation and collation of scientifically valid research, derived from extensive review of published literature. When exercising clinical judgment, health-care providers should incorporate this guideline along with patient's needs, desires, and their values in order to fully and appropriately care for patients with Crohn's disease. This guideline is intended to be flexible, not necessarily indicating the only acceptable approach, and should be distinguished from standards of care that are inflexible and rarely violated. To evaluate the level of evidence and strength of recommendations, we used the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) system. The Committee reviews guidelines in depth, with participation from experienced clinicians and others in related fields. The final recommendations are based on the data available at the time of the production of the document and may be updated with pertinent scientific developments at a later time.

Within-Stool and Within-Day Sample Variability of Fecal Calprotectin in Patients With Inflammatory Bowel Disease: A Prospective Observational Study

BACKGROUND AND GOALS

The use of fecal calprotectin (FC) as a stool biomarker for differentiating inflammatory bowel disease (IBD) from IBS has been well validated, and there is a strong correlation between FC and the presence of endoscopic inflammatory lesions. However, recent studies have demonstrated intraindividual sample variability in patients with IBD, possibly limiting the reliability of using a single sample for monitoring disease activity. Our aim was to assess the within-stool and within-day sample variability of FC concentrations in patients with IBD.

STUDY

We examined a cross-sectional cohort of 50 adult IBD patients. Eligible patients were instructed to collect 3 samples from different parts of the stool from their first bowel movement of the day and 3 samples from each of up to 2 additional bowel movements within 24 hours. FC concentrations were measured by a rapid, quantitative point-of-care test using lateral flow technology (Quantum Blue). Descriptive statistics were used to assess FC variability within a single bowel movement and between different movements at different FC positivity cutoffs.

RESULTS

Within a single bowel movement, there was clinically significant sample variability ranging from 8% to 23% depending on the time of the day or on the FC positivity cutoff value. Between bowel movements, there was clinically significant sample variability ranging from 13% to 26% depending on the FC positivity cutoff.

CONCLUSIONS

Considering a single FC sample, the first sample of the day with an FC positivity cutoff of 250 μg/g provided the most reliable indication of disease activity.

Accuracy of Consecutive Fecal Calprotectin Measurements to Predict Relapse in Inflammatory Bowel Disease Patients Under Maintenance With Anti-TNF Therapy: A Prospective Longitudinal Cohort Study

BACKGROUND AND GOAL

Predicting relapse in inflammatory bowel disease (IBD) patients could allow early changes in therapy. We aimed at evaluating the accuracy of consecutive fecal calprotectin (FC) measurements to predict flares in IBD patients under maintenance treatment with anti-tumor necrosis factor (TNF) drugs.

STUDY

A prospective longitudinal cohort study with 16-month follow-up period was designed. IBD patients in clinical remission for at least 6 months under anti-TNF therapy were included. FC was quantified at 4-month intervals for 1 year, and patients were clinically evaluated for relapse at 2-month intervals. Diagnostic accuracy of FC for predicting relapse was evaluated by receiver-operating characteristic curve analysis.

RESULTS

In total, 95 of 106 included patients finalized the study and were analyzed (median age 44 y, 50.5% female, 75% with Crohn's disease). A total of 30 patients (31.6%) had a relapse over follow-up. FC concentration was significantly higher in patients who relapsed (477 μg/g) than in patients who maintained in remission (65 μg/g) (P<0.005). The optimal cutoff to predict remission was 130 μg/g (negative predictive value of 100%), and 300 μg/g to predict relapse (positive predictive value of 78.3%).

CONCLUSIONS

FC is a good predictor of clinical relapse and a particularly good predictor of remission over the following 4 months in patients with IBD on maintenance therapy with anti-TNF drugs. FC levels <130 μg/g is consistently associated with maintained disease remission, whereas concentrations >300 μg/g allow predicting relapse with a high probability at any time over the following 4 months.

Can faecal calprotectin predict relapse in inflammatory bowel disease: a mini review

Crohn's disease and ulcerative colitis are chronic inflammatory disorders affecting the gastrointestinal tract. Faecal calprotectin is a protein complex of the S-100 family of calcium-binding proteins present in inflammatory cells that can be measured in stool samples, which act as a biomarker for bowel inflammation. Elevated faecal calprotectin has been shown to reflect the presence of ongoing mucosal inflammation, which improves with mucosal healing. The aim of this review was to evaluate the available evidence on the ability of faecal calprotectin to predict a relapse in inflammatory bowel disease. Multiple retrospective studies have shown that patients who relapse have significantly higher levels of calprotectin in their stool compared with non-relapsers, especially in ulcerative colitis. Elevated faecal calprotectin postoperatively in Crohn's disease was also shown to be indicative of a relapse. However, the association of a raised faecal calprotectin and relapse is not universal and may be explained by the different patterns of mucosal inflammatory activity that exist. In conclusion, we put forward our hypothesis that changes such as a rise in faecal calprotectin levels may be more predictive of a relapse than absolute values.

Outcomes of limited period of adalimumab treatment in moderate to severe Crohn's disease patients: Taiwan Society of Inflammatory Bowel Disease Study

Background/Aims

In Taiwan, due to budget limitations, the National Health Insurance only allows for a limited period of biologics use in treating moderate to severe Crohn's disease (CD). We aimed to access the outcomes of CD patients following a limited period use of biologics, specifically focusing on the relapse rate and remission duration; also the response rate to second use when applicable.

Methods

This was a multicenter, retrospective, observational study and we enrolled CD patients who had been treated with adalimumab (ADA) according to the insurance guidelines from 2009 to 2015.

Results

A total of 54 CD patients, with follow-up of more than 6 months after the withdrawal of ADA, were enrolled. The average period of treatment with ADA was 16.7±9.7 months. After discontinuing ADA, 59.3% patients suffered a clinical relapse. In the univariate analysis, the reason for withdrawal was a risk factor for relapse (P=0.042). In the multivariate analysis, current smoker became an important risk factor for relapse (OR, 3.9; 95% CI, 1.2−14.8; P=0.044) and male sex was another risk factor (OR, 2.9; 95% CI, 1.1−8.6; P=0.049). For those 48 patients who received a second round of biologics, the clinical response was seen in 60.4%, and 1 anaphylaxis occurred.

Conclusions

Fifty-nine percent of patients experienced a relapse after discontinuing the limited period of ADA treatment, and most of them occurred within 1 year following cessation. Male sex and current smoker were risk factors for relapse. Though 60.4% of the relapse patients responded to ADA again.

Validation of a care pathway for the use of faecal calprotectin in monitoring patients with Crohn's disease

INTRODUCTION

We have previously published an evidence-based care pathway for the use of faecal calprotectin (FC) to monitor patients with Crohn's disease established on therapy. Patients are treated as low, intermediate or high risk of continuing Crohn's disease activity based on their FC, whatever their phenotype and surgical status are. Low-risk patients (FC <100 µg/g) are offered 12 monthly follow-ups or step down of therapy if asymptomatic or initial expectant symptomatic treatment. Intermediate-risk patients (FC 100-250 µg/g) are reviewed at 6 months with a repeat FC. High-risk patients (two consecutive FCs >250 µg/g) are flagged up to the responsible clinician as likely having an active Crohn's disease.

METHODS

To validate this care pathway over a 2-year period, by determining its negative predictive value (NPV) and positive predictive value (PPV).

RESULTS

123 patients were managed by means of the care pathway for a mean of 24.4 months. The NPV and PPV were 0.97 (CI 0.93 to 0.98) and 0.85 (CI 0.80 to 0.94), respectively (sensitivity: 0.92 (0.83 to 0.96) and specificity: 0.95 (0.92 to 0.98)). Importantly 69% of patients with FC >250 µg/g were in clinical remission, the care pathway identifying patients who would benefit from presymptomatic disease modification.

CONCLUSIONS

This validation of a pragmatic clinical care pathway demonstrates a safe and effective mechanism by which to use FC to monitor risk of disease activity in patients with Crohn's disease established on therapy. It provides a framework for prioritising follow-up and for identifying patients at risk of continuing disease activity or those in whom therapy could be stepped down.

Diffusion-weighted imaging in quiescent Crohn's disease: correlation with inflammatory biomarkers and video capsule endoscopy

AIM

To investigate the role of restricted diffusion in quiescent Crohn's disease (CD) patients and its association with inflammatory biomarkers and endoscopic disease.

MATERIAL AND METHODS

Fifty-two quiescent CD patients prospectively underwent magnetic resonance enterography (MRE) and video capsule endoscopy (VCE) and were tested for the inflammatory biomarkers, faecal calprotectin (FCP) and C-reactive protein (CRP). Restricted diffusion in the distal ileum was qualitatively (absence/presence) and quantitatively (apparent diffusion coefficient [ADC]) assessed by two readers. The VCE-based Lewis score was calculated for the distal ileum. Restricted diffusion sensitivity and specificity for VCE ulcerations were assessed for patients with elevated (>100 μg/g) or normal (<100 μg/g) FCP. Receiver operating characteristic (ROC) curve was used to assess the ability of ADC to identify patients with concurrent VCE ulceration and elevated FCP.

RESULTS

The sensitivity and specificity of restricted diffusion for patients with VCE ulceration were higher in patients with elevated FCP (reader 1: 71.4%, 80%, reader 2: 76.2%, 100%, respectively) compared to patients with normal FCP (reader 1: 46.2%, 61.5%; reader 2: 15.4%, 76.9%, respectively). The ADC had a high diagnostic accuracy for identifying patients that had concurrent VCE ulceration and elevated FCP (reader 1: AUC=0.819, reader 2: AUC=0.832).

CONCLUSION

In quiescent CD patients, the presence of restricted diffusion is suggestive of an active inflammation, associated with elevated FCP. Thus, DWI may serve as a clinical tool in the follow-up of these patients, implying subclinical inflammatory flares.

Clinical implications of assay specific differences in f-calprotectin when monitoring inflammatory bowel disease activity over time

OBJECTIVE

With several faecal calprotectin (FC) assays on the market, it has been difficult to define a uniform threshold for discriminating between remission and active disease in patients with inflammatory bowel disease (IBD). We aimed to compare the results of different FC-assays in IBD patients, followed over time.

MATERIAL AND METHODS

IBD patients provided faecal samples and reported clinical activity every third month prospectively over a two year period. FC was measured with two ELISA - (Bühlmann and Immunodiagnostik) and one automated fluoroimmunoassay (Phadia).

RESULTS

In total, 13 patients provided 91 faecal samples. The median (IQR) concentration of FC was higher at active disease than at remission for all assays: Bühlmann 845 (1061-226) μg/g versus 62 (224-39) μg/g, Phadia 369 (975-122) μg/g versus 11 (52-11) μg/g, and Immundiagnostik 135 (302-69) μg/g versus 8 (56-4) μg/g. The Bühlmann assay produced the largest absolute difference but the corresponding relative difference seemed to be more pronounced when analysed by the Phadia - (ratio of means 8.5; 95% CI 3.3-21.9) or the Immundiagnostik assay (ratio of means 7.4; 95% CI 3.1-17.6) than by the Bühlmann assay (ratio of means 5.3; 95% CI 2.7-10.6). Consequently, the specificity for discriminating active disease from remission varied between assays (34-75%) when the cut-off 50 μg/g was used, whereas the differences in sensitivity were less pronounced.

CONCLUSIONS

Cross-comparisons revealed overall poor agreement between the assays as well as differences in the dynamics of FC. These findings suggest that standardisation of the method is needed to implement FC as a disease monitoring tool at large-scale.

Compliance with the faecal calprotectin test in patients with inflammatory bowel disease

BACKGROUND

We investigated, for the first time, levels of compliance with faecal calprotectin test in inflammatory bowel disease patients.

METHODS

All consecutive adult inflammatory bowel disease patients having been prescribed an faecal calprotectin test between December 2014-July 2015 were included. At their next visit to the hospital, patients had to return a stool sample for the faecal calprotectin test and answer a simple questionnaire: 'Have you brought a stool sample? If not, why not? If so, did you encounter any difficulties when collecting the sample? Were you aware of faecal calprotectin before being asked to take the test?'.

RESULTS

One hundred and one patients were included (50 men; 77 patients with Crohn's disease). The range age was 40 years (19-68). Eighty-nine patients were being treated with infliximab, 10 were on vedolizumab, and two were not being treated with a biologic. Thirty-seven patients (35%) had performed the faecal calprotectin test. Eighty-one patients (80%) had not been aware of faecal calprotectin before being asked to take the test. Of the 64 patients who did not take the test, the prime reasons for non-compliance were forgetfulness (n = 49, 76.6%), a lack of perceived benefit for the test (n = 7, 11%), constipation (n = 5, 7.8%), refusal to handle faeces (n = 2, 3.1%), and difficulty collecting the stool sample (n = 1, 1.5%).

CONCLUSION

Only one-third of the patients performed the faecal calprotectin test. The main reason for non-compliance was forgetfulness. Our present results emphasise the need for better patient education on the importance of complying with faecal calprotectin testing and the future of faecal calprotectin testing at home.

The Value of Fecal Markers in Predicting Relapse in Inflammatory Bowel Diseases

The inflammatory bowel diseases (IBDs) are lifelong chronic illnesses that place an immense burden on patients. The primary aim of therapy is to reduce disease burden and prevent relapse. However, the occurrence of relapses is often unpredictable. Current disease monitoring is primarily by way of clinical indices, with relapses often only recognized once the inflammatory episode is established with subsequent symptoms and gut damage. The window between initial upregulation of the inflammatory response and the recognition of symptoms may provide an opportunity to prevent the relapse and associated morbidity. This review will describe the existing literature surrounding predictive indicators of relapse of IBD with a specific focus on fecal biomarkers. Fecal biomarkers offer promise as a convenient, non-invasive, low cost option for disease monitoring that is predictive of subsequent relapse. To exploit the potential of fecal biomarkers in this role, further research is now required. This research needs to assess multiple fecal markers in context with demographics, disease phenotype, genetics, and intestinal microbiome composition, to build disease behavior models that can provide the clinician with sufficient confidence to intervene and change the long-term disease course.

Usefulness of a rapid faecal calprotectin test to predict relapse in Crohn's disease patients on maintenance treatment with adalimumab

BACKGROUND AND AIM

Predicting relapse in Crohn's disease (CD) patients by measuring non-invasive biomarkers could allow for early changes of treatment. Data are scarce regarding the utility of monitoring calprotectin to predict relapse. The aim of the study was to evaluate the predictive value of a rapid test of faecal calprotectin (FC) to predict for flares in CD patients on maintenance treatment with adalimumab (ADA).

METHODS

A prospective, observational cohort study was designed. Inclusion criteria were CD patients in clinical remission on a standard dose of ADA therapy. Fresh FC was measured using a rapid test.

RESULTS

Thirty patients were included (median age 38 years, 56.7% female). After the 4 months follow-up, 70.0% patients remained in clinical remission and 30.0% had a relapse. FC concentration at inclusion was significantly higher in those patients who relapsed during the follow-up (625 μg/g) compared to those who stayed in remission (45 μg/g). The optimal cut-off for FC to predict relapse was 204 μg/g. The area under the receiver-operating characteristic curve was 0.968. Sensitivity, specificity, positive, and negative predictive value of FC to predict relapse were 100%, 85.7%, 74.1%, and 100%, respectively.

CONCLUSION

In CD patients on ADA maintenance therapy, FC levels measured with a rapid test allow relapse over the following months to be predicted with high accuracy. Low FC levels exclude relapse within at least 4 months after testing, whereas high levels are associated with relapse in three out of every four patients.