Clinical utility of fecal biomarkers for the diagnosis and management of inflammatory bowel disease

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

BACKGROUND

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

AIM

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

METHODS

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

RESULTS

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

CONCLUSION

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

Characterization of physical and chemical properties of dietary fiber from grain bran and its regulation of gut microbiota and metabolite to prevent colitis

Grain bran dietary fiber (DF) has the effect of promoting intestinal health and is worth being studied. In the present study, the physicochemical properties and prevention effect of DF on ulcerative colitis (UC) were investigated. The results showed that the optimal extraction conditions were determined as α-amylase (350 U/g, 70 °C, pH 7.0, 2.5 h) and papain (100 U/g, 60 °C, pH 7.0, 1.5 h), resulting in a yield of 83.81% for DF. Moreover, DF exhibited unique physicochemical properties contributing to its preventive effects, as evidenced by its ability to mitigate symptoms such as hematochezia, immune inflammation, and impaired intestinal barrier in UC mice. The underlying mechanism can be attributed to the regulation of phenylalanine, tyrosine and tryptophan biosynthesis pathway and maintenance of intestinal microbial homeostasis. Therefore, our study suggests that grain bran DF holds potential for the prevention of UC, providing a basis for the development and utilization of grain bran.

Imaging of Ulcerative Colitis: The Role of Diffusion-Weighted Magnetic Resonance Imaging

Magnetic resonance imaging (MRI) has emerged as a promising and appealing alternative to endoscopy in the objective assessment of patients with inflammatory bowel disease (IBD). Diffusion-weighted imaging (DWI) is a specialized imaging technique that enables the mapping of water molecule diffusion within biological tissues, eliminating the need for intravenous gadolinium contrast injection. It is expanding the capability of traditional MRI sequences in Ulcerative Colitis (UC). Recently, there has been growing interest in the application of intravoxel incoherent motion (IVIM) imaging in the field of IBD. This technique combines diffusion and perfusion information, making it a valuable tool for assessing IBD treatment response. Previous studies have extensively studied the use of DWI techniques for evaluating the severity of activity in IBD. However, the majority of these studies have primarily focused on Crohn's disease (CD), with only a limited number of reports specifically examining UC. Therefore, this review briefly introduces the basics of DWI and IVIM imaging and conducts a review of relevant studies that have investigated its application in UC to show whether these techniques are useful techniques for evaluating patients with UC in terms of detection, characterization, and quantification of disease activity. Through the extensive literature survey, most of these studies indicate that DWI proves valuable in the differential diagnosis of UC and could be used as an effective modality for staging UC.

Comprehensive profiling of the human fecal proteome from IBD patients with DIA-MS enables evaluation of disease-relevant proteins

PURPOSE

Inflammatory bowel disease (IBD), which includes ulcerative colitis (UC) and Crohn's disease (CD), is characterized by chronic gastrointestinal inflammation. A high unmet need exists for noninvasive biomarkers in IBD to monitor changes in disease activity and guide treatment decisions. Stool is an easily accessed, disease proximal matrix in IBD, however the composition of the IBD fecal proteome remains poorly characterized.

EXPERIMENTAL DESIGN

A data-independent acquisition LC-MS/MS approach was used to profile the human fecal proteome in two independent cohorts (Cohort 1: healthy n = 5, UC n = 5, CD n = 5, Cohort 2: healthy n = 20, UC n = 10, and CD n = 10) to identify noninvasive biomarkers reflective of disease activity.

RESULTS

688 human proteins were quantified, with 523 measured in both cohorts. In UC stool 96 proteins were differentially abundant and in CD stool 126 proteins were differentially abundant compared to healthy stool (absolute log2 fold change > 1, p-value < 0.05). Many of these fecal proteins are associated with infiltrating immune cells and ulceration/rectal bleeding, which are hallmarks of IBD pathobiology. Mapping the identified fecal proteins to a whole blood single-cell RNA sequencing data set revealed the involvement of various immune cell subsets to the IBD fecal proteome.

CONCLUSIONS AND CLINICAL RELEVANCE

Findings from this study not only confirmed the presence of established fecal biomarkers for IBD, such as calprotectin and lactoferrin, but also revealed new fecal proteins from multiple pathways known to be dysregulated in IBD. These novel proteins could serve as potential noninvasive biomarkers to monitor specific aspects of IBD disease activity which could expedite clinical development of novel therapeutic targets.

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.

Diagnostic Procedures for Inflammatory Bowel Disease: Laboratory, Endoscopy, Pathology, Imaging, and Beyond

Diagnosing inflammatory bowel disease (IBD) can often be challenging, and differentiating between Crohn's disease and ulcerative colitis can be particularly difficult. Diagnostic procedures for IBD include laboratory tests, endoscopy, pathological tests, and imaging tests. Serological and stool tests can be easily performed in an outpatient setting and provide critical diagnostic clues. Although endoscopy is an invasive procedure, it offers essential diagnostic information and allows for tissue biopsy and therapeutic procedures. Video capsule endoscopy and device-assisted enteroscopy are endoscopic procedures used to evaluate the small bowel. In addition to endoscopy, magnetic resonance imaging, computed tomography, and ultrasound (US) are valuable tools for small bowel assessment. Among these, US is noninvasive and easily utilized, making its use highly practical in daily clinical practice. Endoscopic biopsy aids in the diagnosis of IBD and is crucial for assessing the histological activity of the disease, facilitating a thorough evaluation of disease remission, and aiding in the development of treatment strategies. Recent advances in artificial intelligence hold promise for enhancing various aspects of IBD management, including diagnosis, monitoring, and precision medicine. This review compiles current procedures and promising future tools for the diagnosis of IBD, providing comprehensive insights.

Inflammatory Bowel Disease: A Comprehensive Analysis of Molecular Bases, Predictive Biomarkers, Diagnostic Methods, and Therapeutic Options

In inflammatory bowel diseases (IBDs), such as Crohn's disease (CD) and ulcerative colitis (UC), the immune system relentlessly attacks intestinal cells, causing recurrent tissue damage over the lifetime of patients. The etiology of IBD is complex and multifactorial, involving environmental, microbiota, genetic, and immunological factors that alter the molecular basis of the organism. Among these, the microbiota and immune cells play pivotal roles; the microbiota generates antigens recognized by immune cells and antibodies, while autoantibodies target and attack the intestinal membrane, exacerbating inflammation and tissue damage. Given the altered molecular framework, the analysis of multiple molecular biomarkers in patients proves exceedingly valuable for diagnosing and prognosing IBD, including markers like C reactive protein and fecal calprotectin. Upon detection and classification of patients, specific treatments are administered, ranging from conventional drugs to new biological therapies, such as antibodies to neutralize inflammatory molecules like tumor necrosis factor (TNF) and integrin. This review delves into the molecular basis and targets, biomarkers, treatment options, monitoring techniques, and, ultimately, current challenges in IBD management.

Core microbiome-associated proteins associated with ulcerative colitis interact with cytokines for synergistic or antagonistic effects on gut bacteria

Inflammatory bowel disease (IBD), including Crohn's disease (CD) and ulcerative colitis (UC), is associated with a loss or an imbalance of host-microorganism interactions. However, such interactions at protein levels remain largely unknown. Here, we applied a depletion-assisted metaproteomics approach to obtain in-depth host-microbiome association networks of IBD, where the core host proteins shifted from those maintaining mucosal homeostasis in controls to those involved in inflammation, proteolysis, and intestinal barrier in IBD. Microbial nodes such as short-chain fatty-acid producer-related host-microbial crosstalk were lost or suppressed by inflammatory proteins in IBD. Guided by protein-protein association networks, we employed proteomics and lipidomics to investigate the effects of UC-related core proteins S100A8, S100A9, and cytokines (IL-1β, IL-6, and TNF-α) on gut bacteria. These proteins suppressed purine nucleotide biosynthesis in stool-derived in vitro communities, which was also reduced in IBD stool samples. Single species study revealed that S100A8, S100A9, and cytokines can synergistically or antagonistically alter gut bacteria intracellular and secreted proteome, with combined S100A8 and S100A9 potently inhibiting beneficial Bifidobacterium adolescentis. Furthermore, these inflammatory proteins only altered the extracellular but not intracellular proteins of Ruminococcus gnavus. Generally, S100A8 induced more significant bacterial proteome changes than S100A9, IL-1β, IL-6, and TNF-α but gut bacteria degrade significantly more S100A8 than S100A9 in the presence of both proteins. Among the investigated species, distinct lipid alterations were only observed in Bacteroides vulgatus treated with combined S100A8, S100A9, and cytokines. These results provided a valuable resource of inflammatory protein-centric host-microbial molecular interactions.

Stool titanium dioxide is positively associated with stool alpha-1 antitrypsin and calprotectin in young healthy adults

Titanium dioxide (TiO2/E171) is used widely in foods, primarily as a food additive. Animal models have shown that chronic TiO2 exposure may disturb homeostasis of the gastrointestinal tract by increasing gut permeability, inducing gut inflammation, and increasing the likelihood of microbial infection. Adults have a wide range of ingested TiO2,which span two to three orders of magnitude, with a small portion of individuals consuming near gram quantities of TiO2/day. However, research on the health effects of chronic ingestion of TiO2/E171 in humans is limited. We hypothesized that regularly ingested TiO2/E171 is associated with increased gut inflammation and gut permeability in healthy adults. We tested this hypothesis in a cross-sectional design by measuring clinically established stool markers of gut inflammation (calprotectin, lactoferrin) and gut permeability (alpha-1 antitrypsin; A1AT) in 35 healthy adults, and comparing these markers between relatively high and low TiO2 exposure groups. Participants were stratified by TiO2 stool content (high dry stool TiO2 content: 0.95-9.92 μg/mg, n = 20; low content: 0.01-0.04 μg/mg; n = 15). Differences in gut health markers were tested between high and low exposure groups by independent samples t-test or Mann-Whitney U test. Multivariable linear regression was used to assess the association between TiO2 in dry stool and measured stool alpha-1 antitrypsin (A1AT). Participants in the high stool TiO2 group had greater stool A1AT (42.7 ± 21.6 mg/dL; median: 38.3; range: 1.0-49.2 mg/dL), compared to the low TiO2 group (22.8 ± 13.6 mg/dL; median: 20.9; range: 8.7-93.0 mg/dL), P = 0.003. There was also greater stool calprotectin in the high TiO2 group (51.4 ± 48.6 μg/g; median 29.2 μg/g; range: 15.3-199.0 μg/g) than in the low group (47.5 ± 63.3 μg/g; median 18.8 μg/g; range: 1.6-198.1 μg/g), P = 0.04. No clear difference was observed for lactoferrin (high TiO2 group 1.6 ± 2.1 μg/g; median: 0.68 μg/g; range: 0.01-7.7 μg/g, low TiO2 group: 1.3 ± 2.6 μg/g; median: 0.2; range: 0.01-7.6 μg/g) (P = 0.15). A1AT concentration was positively associated with stool TiO2, after adjusting for confounders (β ± SE: 19.6 ± 7.2; P = 0.01) R2 = 0.38). Community dwelling, healthy adults with the highest TiO2 stool content had higher stool A1AT and calprotectin, compared to those with the lowest TiO2 stool content. Ongoing research is needed to validate these observations in larger groups, and to determine the long-term effects of ingested TiO2 on human gut health, using these and additional health endpoints.

Alteration of stool pH and its association with biomarkers of gut enteropathy among slum-dwelling women of reproductive age in Bangladesh

BACKGROUND

Recent evidence suggests that measures of maternal gut enteropathy are associated with unfavorable fetal outcomes. It is, therefore, crucial to identify and treat the features of intestinal enteropathy among reproductive-age women living in areas where enteropathy is highly prevalent. However, there is a lack of non-invasive diagnostic tests to determine EED, making it difficult to identify the disease in field settings. In this study, we tested the potential of fecal pH as a biomarker of gut enteropathy and investigated its relationship with fecal biomarkers of intestinal enteropathy in reproductive-age women living in resource-limited environments.

METHODS

Data on socio-demographic information, anthropometry, and biological samples were collected from 78 apparently healthy women aged between 20 and 27 years from November 2018 to December 2019. The association of stool pH with two fecal biomarkers of gut enteropathy (i.e., intestinal alkaline phosphatase [IAP] and fecal lipocalin-2 [LCN-2] was investigated using multiple linear regression models after adjusting for relevant covariates.

RESULTS

In the adjusted models, alkaline stool pH (pH > 7.2) was found to be significantly associated with a decrease in the fecal IAP level by 1.05 unit (95% CI: -1.68, -0.42; p < 0.001) in the log scale, and acidic stool pH (pH < 6) was found to be significantly associated with an increase in the fecal LCN-2 level by 0.89 units (95% CI: 0.12, 1.67; p < 0.025) in the log scale.

CONCLUSIONS

The study findings demonstrated an association of fecal pH with biomarkers of gut enteropathy indicating its applicability as a simple tool for understanding intestinal enteropathy among reproductive-age women living in resource-limited settings.

Validation of the fCAL turbo immunoturbidimetric assay for measurement of calprotectin in porcine and bovine fecal samples

The concentration of calprotectin in feces is a well-studied marker of gastrointestinal inflammation in humans. However, little is known about fecal calprotectin in farm animals. In this work, we have validated an immunoturbidimetric method for fecal calprotectin (Bühlmann fCAL® turbo assay, Schönenbuch, Switzerland) in porcine and bovine fecal samples. Linearity was evaluated by serial dilution (R2 > 0.97 was obtained for both species). Accuracy was assessed by a recovery study, with results between 80 and 120% for low, medium, and high samples in both species. Intra- and inter-assay variability was <20%. Limit of detection was 6.4 μg/g in pig and 5.3 μg/g in cow. Limit of quantification was 13.4 μg/g (pig) and 11.1 μg/g (cow). Additionally, clinical validation has been included to evaluate the ability of the assay to detect inflammatory status in the intestine under different management conditions. In experiments with porcine, it was found that piglets treated with ZnO had lower concentrations of fecal calprotectin. In a second experiment in bovine, calves with diarrhea had higher concentration of fecal calprotectin. The Bühlmann fCAL® turbo assay is suitable for measurement of calprotectin in porcine and bovine fecal samples. Moreover, fecal calprotectin could be a good biomarker of intestinal inflammation in both species.

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

RATIONALE AND OBJECTIVES

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSION

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

Performance of fecal S100A12 as a novel non-invasive diagnostic biomarker for pediatric inflammatory bowel disease: a systematic review and meta-analysis

OBJECTIVE

The incidence and prevalence of inflammatory bowel disease (IBD) in pediatric patients are increasing. Currently, the diagnostic method for IBD is inconvenient, expensive, and difficult. S100A12, a type of calcium-binding protein, detected in the feces of patients with IBD has recently been suggested as a promising diagnostic tool. Hence, the authors aimed to evaluate the accuracy of fecal S100A12 in diagnosing IBD in pediatric patients by performing a meta-analysis.

METHODS

The authors performed a systematic literature search in five electronic databases for eligible studies up to July 15, 2021. Pooled diagnostic accuracies of fecal S100A12 were analyzed as the primary outcomes. Secondary outcomes were standardized mean difference (SMD) of fecal S100A12 levels between IBD and non-IBD groups and a comparison of diagnostic accuracies between fecal S100A12 and fecal calprotectin.

RESULTS

Seven studies comprising 712 children and adolescents (474 non-IBD controls and 238 IBD cases) were included. Fecal S100A12 levels were higher in the IBD group than in the non-IBD group (SMD = 1.88; 95% confidence interval [CI] = 1.19-2.58; p < 0.0001). Fecal S100A12 could diagnose IBD in pediatric patients with a pooled sensitivity of 95% (95% CI = 88%-98%), specificity of 97% (95% CI = 95%-98%), and area under the receiver operating summary characteristics (AUSROC) curve of 0.99 (95% CI = 0.97-0.99). Fecal S100A12 specificity and AUSROC curve values were higher than those of fecal calprotectin (p < 0.05).

CONCLUSION

Fecal S100A12 may serve as an accurate and non-invasive tool for diagnosing pediatric IBD.

Optimizing maternal and neonatal outcomes through tight control management of inflammatory bowel disease during pregnancy: a pilot feasibility study

A home point-of care FCP test (IBDoc) and a self-reported clinical disease activity program (IBD Dashboard) may improve routine monitoring of IBD activity during pregnancy. We aimed to evaluate the feasibility of tight control management using remote monitoring in pregnant patients with IBD. Pregnant patients (< 20 weeks) with IBD were prospectively enrolled from Mount Sinai Hospital between 2019 and 2020. Patients completed the IBDoc and IBD Dashboard at three core time points. Disease activity was measured clinically using the Harvey-Bradshaw Index (mHBI) for CD and partial Mayo (pMayo) for UC, or objectively using FCP. A feasibility questionnaire was completed in the third trimester. Seventy-seven percent of patients (24 of 31) completed the IBDoc and IBD Dashboard at all core time points. Twenty-four patients completed the feasibility questionnaires. All survey respondents strongly preferred using the IBDoc over standard lab-based testing and would use the home kit in the future. Exploratory analysis identified discordance rates of more than 50% between clinical and objective disease activity. Tight control management using remote monitoring may be feasible among pregnant patients with IBD. A combination of both clinical scores and objective disease markers may better predict disease activity.

Capsule endoscopy in Crohn's disease surveillance: A monocentric, retrospective analysis in Italy

Background

Crohn's disease (CD) is a potentially debilitating condition that burdens Italian healthcare substantially. The symptomatic management relies on prompt therapy adjustment to reduce flares and follow-up diagnostic inputs to maximise remission. Capsule endoscopy (CE) has introduced advantages in CD diagnostics, allowing the direct inspection of the entire gastrointestinal mucosa. The diagnostic procedure is comparable in effort to standard ileocolonoscopy (IC) but requires no anaesthesia. Whether CE follow-up improves clinical outcomes remains to be defined.

Objectives

To provide a preliminary evaluation of CE in terms of clinical outcomes with respect to the standard of care ileocolonoscopy/MRE in Italy.

Methods

This retrospective analysis utilises anonymised, monocentric data from the S. Orsola-Malpighi Hospital IBD database in Bologna, Italy, collected between 1999 and 2019. Out of 421 adult patient records, 100 were included in the analysis (50 per arm, matched per demographic and clinical characteristics). The CE represented the intervention arm, whereas ileocolonoscopy/magnetic resonance enterography was the standard of care. The use of biologics, symptomatology course, and surgery were the outcomes.

Results

The two techniques performed similarly overall. In general, no significant difference emerged in the use of biologics. The use of biologics appears reduced in the CE group, only in L4 patients after the first follow-up year. Similarly, surgery was seemingly less frequent among L4 patients in the CE group. No difference was found between groups in flare occurrence and duration. CE patients might have experienced longer and earlier first remissions, but no long-term difference persisted.

Conclusions

The CE group showed an apparent reduction in biologics and surgery, limiting to L4 diagnoses. More extensive, prospective, multicentre, randomised studies must corroborate these preliminary findings.

Fecal Calprotectin for Small Bowel Crohn's Disease: Is It a Cutoff Issue?

(1) Background: Fecal calprotectin (FC) correlates well with colonic inflammatory activity of Crohn’s disease (CD); data about relation of FC and small bowel (SB) lesions are still contradictory. The main aim was to analyze the relationship between FC levels and SB inflammatory activity in patients with established or suspected Crohn’s disease, assessed by small bowel capsule endoscopy (SBCE) or magnetic resonance enterography (MRE). (2) Methods: Two cohorts of patients were included: 1. Prospective data were collected from patients with established or suspected CD who underwent SBCE and FC (Cohort A); 2. A retrospective cohort of patients who underwent MRE and FC determination (Cohort B). Different cutoffs for FC were tested in both cohorts. (3) Results: 83 patients were included and 66 were finally analyzed. A total of 69.6% had SB lesions seen by SBCE (n = 25) or MRE (n = 21). FC mean levels were 605.74 + 607.07 μg/g (IQ range: 99.00−878.75), being significantly higher in patients with SB lesions compared to patients without lesions (735.91 + 639.70 μg/g (IQ range: 107.75−1366.25) vs. 306.35 + 395.26 μg/g (IQ range: 78.25−411.0), p < 0.005). For cohort A, 25 out of 35 patients had SB lesions and a significant correlation between Lewis Score and FC levels was achieved (R2: 0.34; p = 0.04). FC sensitivity (S), specificity (E), positive predictive value (PPV), and negative predictive values (NPV) for predicting SB lesions were 80%, 50%, 80%, and 50%, respectively, for FC > 100 µg/g. For cohort B, inflammatory SB activity, measured by MaRIA score, was detected in 21 out of 31 patients (67.7%). Patients with positive findings in MRE had significantly higher values of FC than those with no lesions (944.9 + 672.1 µg/g vs. 221 + 212.2 µg/g, p < 0.05). S, E, PPV, and NPV of FC were 89%, 50%, 77.2%, and 71.4% for FC levels > 100 µg/g. The higher sensitivity and specificity of the FC levels for the detection of SB lesions with SBCE and MRE was obtained for an FC cutoff >265 μg/g and >430 μg/g, respectively. (4) Conclusions: FC has a good correlation with the presence of SB lesions, assessed by SBCE and MRE, in patients with established or suspected Crohn’s disease. However, the ideal cutoff is here proven to be higher than previously reported. Multicenter and large prospective studies are needed in order to establish definitive FC cutoff levels.

Non-invasive Monitoring of Pouchitis After Total Proctocolectomy Using Fecal Calprotectin Levels

BACKGROUND

Fecal calprotectin (FC) is the most widely used marker for evaluating the disease activity of ulcerative colitis (UC). However, studies on FC in pouchitis after total proctocolectomy are scarce. We aimed to examine the correlations between the FC level and clinical findings and Pouchitis Disease Activity Index (PDAI) in UC patients who underwent total proctocolectomy (TP) with ileal pouch-anal canal anastomosis (IPAA) or ileal pouch-anal canal anastomosis (IACA).

METHODS

Between April 2008 and March 2018, 15 patients, consisting of 8 males and 7 females, with an average age at operation of 46.5 years, participated in this study. The average observation period was 68.3 months. The subjects underwent FC level measurements and endoscopic examinations.

RESULTS

The mean FC level was 418.69 μg/g (range: 10-1650 μg/g). Pouchitis was found in one (6.6%) patient, as detected by endoscopy. Among the 15 cases, FC levels were positively correlated with white blood cell count as well as albumin and C-reactive protein levels. There was a significant positive correlation between the PDAI score and FC levels (p<0.05). The median FC level was 111 mg/g in those with pouchitis, which was significantly higher than the 16 mg/g in those without pouchitis (p<0.05). Moreover, a significant positive correlation was found between the endoscopic findings of inflammation and FC levels (p<0.00005).

CONCLUSION

FC levels were correlated with the PDAI score, blood testing data, and endoscopic findings, suggesting that the FC level could be a useful index of postoperative pouchitis and ileal pouch condition in patients undergoing TP with IPAA as UC treatment.

Comparative Efficacy of Infliximab vs Ustekinumab for Maintenance of Clinical Response in Biologic Naïve Crohn's Disease

BACKGROUND

There is a need to better understand the positioning of biologic therapies for long-term outcomes in biologic-naïve Crohn's disease (CD). We assessed the comparative effectiveness of infliximab and ustekinumab among induction responders for 1-year outcomes.

METHODS

This post hoc analysis included data from 220 biologic-naïve CD participants with response to induction therapy from 2 clinical trial programs. Participants achieving 1-year clinical remission (CR) (Crohn's disease activity index <150), corticosteroid-free CR, normalization of fecal calprotectin (FC), endoscopic response (Simple Endoscopic Score for CD decrease ≥50% from baseline), and endoscopic remission (ER) (Simple Endoscopic Score for CD <3) were compared. Multivariate logistic regression evaluated the likelihood of achieving the outcomes adjusted for confounders. Propensity score matching created a cohort with similar distribution of baseline covariates.

RESULTS

One-year CR and corticosteroid-free CR rates were similar between infliximab-treated and ustekinumab-treated patients (CR, 66 of 110 [60.0%] vs 63 of 110 [57.3%]; adjusted odds ratio [aOR], 1.15; 95% CI, 0.67-1.98; P = .681; corticosteroid-free CR, 11 of 28 (39.3%) vs 27 of 51 [52.9%]; aOR, 0.58; 95% CI, 0.23-1.47; P = .251). Compared with ustekinumab-treated patients, infliximab-treated participants were more likely to achieve 1-year endoscopic response (43 of 92 [46.7%] vs 6 of 30 [20.0%], aOR, 3.59; 95% CI, 1.34-9.66; P = .011) and ER (31 of 92 [33.7%] vs 4 of 30 [13.3%]; aOR, 3.35; 95% CI, 1.07-10.49; P = .038). Among patients with FC ≥250 mg/kg at baseline, normalization (<250 mg/kg) at 1-year was similar between groups. Similar results were observed within the propensity matched population for all analyses.

CONCLUSIONS

Treatment with infliximab and ustekinumab among induction responders achieved 1-year CR with similar efficacy, but infliximab may confer greater benefit for endoscopic outcomes. Findings should be interpreted with caution as our analyses were unpowered.

The value of fecal calprotectin in Clostridioides difficile infection: A systematic review

As a marker of inflammation, calprotectin has potential application value in a variety of inflammatory diseases, such as arthritis and bacterial infections. Clostridioides difficile infection (CDI) is an infectious disease that causes intestinal damage and inflammation. This systematic review aims to determine whether fecal calprotectin has application value in CDI. Nine databases were searched from inception to 6 June 2022, and 17 studies were included. These studies were divided into four groups according to their content. Generally speaking, fecal calprotectin is not an ideal indicator for the diagnosis and prognosis prediction of CDI but may serve as a potential indicator for assessing disease severity and as a readily detectable marker for CDI screening. In addition, patients in need of treatment or with detectable toxins in stool may tend to have higher levels of fecal calprotectin. In summary, fecal calprotectin has some potential application value in CDI. However, further studies are needed to verify these findings and determine the reliability of calprotectin as a biomarker for CDI.

Fecal Calprotectin Is Increased in Pouchitis and Progressively Increases With More Severe Endoscopic and Histologic Disease

BACKGROUND & AIMS

Data regarding fecal calprotectin (FC), commonly used for noninvasive monitoring in inflammatory bowel diseases, are scarce in patients with ileal pouch-anal anastomosis (IPAA). We aimed to assess the association between FC levels and pouch inflammation in patients with ulcerative colitis who underwent IPAA.

METHODS

A cross-sectional study of adults with ulcerative colitis who underwent IPAA with J-pouch formation prospectively followed in a dedicated pouch clinic. Patients had clinical, endoscopic, and histologic assessments within 90 days of FC sampling. Each patient encounter was evaluated separately. Pouchitis was defined as a Pouchitis Disease Activity Score of ≥7 (maximum score: 18).

RESULTS

Overall, 156 patients had 296 encounters that met inclusion criteria. A total of 52% of patients were male, median age at evaluation was 43 (IQR, 35-58) years, and median pouch age was 10 (interquartile range [IQR], 2.5-15) years. Median FC values were significantly lower in patients without compared with those with pouchitis (208 [IQR, 96-478] μg/g vs 550 [IQR, 250-1051] μg/g; P < .0001). Mean FC values increased among patients with higher endoscopic and histologic scores. FC performed better than C-reactive protein as a predictor of pouchitis. FC of >460 μg/g had >80% specificity for predicting significant endoscopic disease (Pouchitis Disease Activity Score endoscopic subscore ≥5), while an FC of <125 μg/g had over 80% specificity in predicting endoscopic remission.

CONCLUSIONS

FC levels are increased in patients with endoscopic and histologic inflammation of the pouch. FC may be a useful tool in the management of patients following IPAA.

Disease Monitoring in Inflammatory Bowel Disease: Evolving Principles and Possibilities

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

Gut Microbiota Is a Potential Biomarker in Inflammatory Bowel Disease

Inflammatory bowel disease (IBD), which includes ulcerative colitis (UC) and Crohn's disease (CD), is characterized by relapse and remission alternately. It remains a great challenge to diagnose and assess disease activity during IBD due to the lack of specific markers. While traditional biomarkers from plasma and stool, such as C-reactive protein (CRP), fecal calprotectin (FC), and S100A12, can be used to measure inflammation, they are not specific to IBD and difficult to determine an effective cut-off value. There is consensus that gut microbiota is crucial for intestinal dysbiosis is closely associated with IBD etiopathology and pathogenesis. Multiple studies have documented differences in the composition of gut microbiota between patients with IBD and healthy individuals, particularly regarding microbial diversity and relative abundance of specific bacteria. Patients with IBD have higher levels of Proteobacteria and lower amounts of Bacteroides, Eubacterium, and Faecalibacterium than healthy individuals. This review summarizes the pros and cons of using traditional and microbiota biomarkers to assess disease severity and treatment outcomes and addresses the possibility of using microbiota-focused interventions during IBD treatment. Understanding the role of microbial biomarkers in the assessment of disease activity and treatment outcomes has the potential to change clinical practice and lead to the development of more personalized therapies.

Evaluation of Serum Calprotectin Levels in Patients with Inflammatory Bowel Disease

BACKGROUND

Fecal calprotectin has been proposed as a useful biomarker of disease activity in inflammatory bowel disease (IBD). However, the role of calprotectin in systemic circulation is not well established. Thus, this study aimed to quantify serum calprotectin levels to identify a potential inflammatory marker for IBD.

METHODS

Ninety-eight patients with ulcerative colitis (UC) and 105 patients with Crohn's disease (CD) were prospectively enrolled and clinically scored. Ninety-two healthy, age-matched subjects served as controls. Blood samples from UC and CD patients and controls were analyzed for serum calprotectin levels and routine laboratory parameters. Disease activity was assessed by partial Mayo score and Harvey-Bradshaw index for UC and CD, respectively.

RESULTS

Serum calprotectin levels were higher in CD and UC patients than in controls and were higher during active disease than during inactive disease in CD but not in UC. In UC, serum calprotectin levels were correlated with C-reactive protein (CRP) but not with other laboratory parameters or disease activity. In CD, serum calprotectin levels were positively correlated with disease activity, serum CRP, and platelet count. In UC and CD, serum calprotectin and CRP levels increased during the acute phase and decreased towards remission.

CONCLUSIONS

Serum calprotectin is an inflammatory marker in IBD but might be more effective in evaluating patients with CD than those with UC. Further studies are needed to confirm these findings and to better determine the specific uses of serum calprotectin in routine practice.

Histologic Features of Colon Biopsies (Geboes Score) Associated With Progression of Ulcerative Colitis for the First 36 Months After Biopsy

BACKGROUND & AIMS

In addition to findings from endoscopy, histologic features of colon biopsies have been associated with outcomes of patients with ulcerative colitis (UC). We investigated associations between Geboes scores (a system to quantify structural changes and inflammatory activity in colon biopsies) and UC progression, and the time period over which this association is valid.

METHODS

We analyzed data from 399 asymptomatic patients with UC enrolled in the ACERTIVE study, followed at 13 inflammatory bowel disease (IBD) centers in Portugal through 31 December 2019. Blood and stool samples were collected and analyzed, and all patients underwent sigmoidoscopy within 24 h of sample collection. We assessed baseline endoscopic status (Mayo endoscopic subscore), histologic features of 2 sigmoid and 2 rectal biopsies (Geboes score), and concentration of fecal calprotectin (FC). The primary outcome was UC progression (surgical, pharmacologic, and clinical events). We generated survival curves for 36 months or less and more than 36 months after biopsy according to Geboes score using the Kaplan-Meier method and compared findings with those from a log rank test. Cox regression was adjusted for Mayo endoscopic subscore, Geboes score, and level of FC; results were expressed as adjusted hazard ratios (HR) with 95% CIs.

RESULTS

Patients with Geboes scores >2B.0, Geboes scores >3.0, or Geboes scores >4.0 had a higher frequency of, and a shorter time to UC progression, than patients with Geboes scores ≤2B.0, Geboes scores ≤3.0, or Geboes score ≤4.0 (P < .001). Disease progression occurred earlier in patients with Geboes scores >2B.0, Geboes scores >3.0, or Geboes scores >4.0 compared with patients with Geboes scores ≤2B.0 (HR, 2.021; 95% CI, 1.158-3.526), Geboes scores ≤3.0 (HR, 2.007; 95% CI, 1.139-3.534), or Geboes scores ≤4.0 (HR, 2.349; 95% CI, 1.269-4.349), respectively, in the first 36 months after biopsy. Similar results were found for patients with concentrations of FC below 150 μg/g.

CONCLUSIONS

We found histologic features of colon biopsies (Geboes score) to be an independent risk factor for progression of UC in the first 36 months after biopsy.

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

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

Methods

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

Results

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

Conclusions

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

Capsule Endoscopy in Crohn's Disease-From a Relative Contraindication to Habitual Monitoring Tool

Crohn’s disease (CD) is a chronic inflammatory disorder that may involve the gastrointestinal tract from the mouth to the anus. Habitual disease monitoring is highly important during disease management, aiming to identify and treat disease exacerbations, in order to avoid immediate and future complications. Currently, ilio-clonoscopy is the gold standard for mucosal assessment. However, the procedure is invasive, involves sedation and allows for visualization of the colon and only a small part of the terminal ileum, while most of the small bowel is not visualized. Since CD may involve the whole length of the small bowel, the disease extent might be underestimated. Capsule endoscopy (CE) provides a technology that can screen the entire bowel in a non-invasive procedure, with minimal side effects. In recent years, this technique has gained in popularity for CD evaluation and monitoring. When CE was first introduced, two decades ago, the fear of possible capsule retention in the narrowed inflamed bowel lumen limited its use in CD patients, and a known CD located at the small bowel was even regarded as a relative contraindication for capsule examination. However, at present, as experience using CE in CD patients has accumulated, this procedure has become one of the accepted tools for disease diagnosis and monitoring. In our current review, we summarize the historic change in the indications and contraindications for the usage of capsule endoscopy for the evaluation of CD, and discuss international recommendations regarding CE’s role in CD diagnosis and monitoring.

Monitoring established Crohn's disease with pan-intestinal video capsule endoscopy in Europe: clinician consultation using the nominal group technique

OBJECTIVE

Monitoring established Crohn's disease (CD) through a "treat-to-target" strategy aims to reduce and prevent long-term bowel damage and disability. Despite the availability of different monitoring techniques, there is a current lack of integrated evidence to guide optimal monitoring in terms of appropriate tools and timing. Pan-intestinal video capsule endoscopy (PCE) enables non-invasive and direct visualization of the entire intestinal tract with proven safety and efficacy. This study aims to generate insights on the value of PCE for monitoring established CD from the physician's perspective.

METHODS

The Nominal Group Technique (NGT) was used to create discussion around pre-defined research questions aimed at identifying target patient populations for PCE, benefits of PCE in terms of improving disease management, comparative benefits of PCE over standard of care, research priorities to ratify the use of PCE, and hurdles to PCE utilization. A NGT panel was held in Brussels, Belgium in October 2018 with 9 gastroenterology experts. Data were collected from multiple rankings of statements to the research questions and analyzed descriptively.

RESULTS

Consensus indicated that PCE is differentiated from other diagnostic tools, allowing for non-invasive and direct visualization of the luminal intestinal tract in one single procedure. Participants agreed that PCE is beneficial for mapping and grading established CD in all patients, enabling individual and tailored treatment decision-making. Time required to read PCE results was identified as the main utilization hurdle by participants. Well-designed studies are needed to confirm improved outcomes amongst patients with CD managed through a PCE-guided approach.

CONCLUSIONS

This study, using the NGT, generated expert opinion on the value of PCE for monitoring established CD in terms of target patient populations and benefits compared to other diagnostic modalities. Participants perceived PCE to facilitate a "treat-to-target" strategy for CD management. Further research is needed to support this value perception.

A comparison of diagnostic performance between two quantitative rapid fecal calprotectin assays in detecting active inflammatory bowel disease

Background

Fecal calprotectin (FC) is widely used for the diagnosis and monitoring disease activity of inflammatory bowel disease (IBD). Quantitative rapid assays can be a reliable alternative to the time-consuming assay. This study aimed to evaluate and compare the diagnostic performance of two quantitative rapid FC assays (Ichroma calprotectin, and Buhlmann Quantum blue).

Methods

A total of 192 patients were included in this study; 84 patients with IBD (67 ulcerative colitis and 17 Crohn’s disease) and 108 patients with non-IBD. We compared quantitative FC levels in different disease statuses and evaluated the correlation between the FC results of the two FC kits. Diagnostic performances in predicting active IBD were evaluated in reference to different cut-off levels.

Results

The FC levels in 45 patients with active IBD as defined by endoscopic score were significantly higher compared to the inactive IBD and other diseases (P<0.05). Although the two assays’ results correlated (r = 0.642, P < 0.001), a significant deviation was observed (y (Buhlmannn) = -45.2 +8.9X (Ichroma)). The Diagnostic performances in predicting active IBD were comparable as area under the curve (AUC), 0.812, cut-off, 50, sensitivity, 64.4%, and specificity, 85.0% for iChroma assay and AUC, 0.826, cut-off, 100, sensitivity, 84.4%, and specificity 61.9% for Buhlmann Quantum Blue assay. FC levels using a cut-off of > 250 μg/g confirmed 85.7% (iChroma) and 64.1% (Buhlmann) of active IBD patients.

Conclusion

The results of the two rapid FC assays iChroma and Buhlmann showed a significant correlation, but the two test results were not interchangeable. With optimized cut-off values, rapid FC tests could be helpful in the diagnosis of IBD and differentiating active IBD from inactive or organic bowel disease.

Lewis score on capsule endoscopy can predict the prognosis in patients with small bowel lesions of Crohn's disease

BACKGROUND AND AIM

Endoscopic evaluation of disease activity, including mucosal healing, is poorly established in Crohn's disease. We previously reported that patients with a Lewis score (LS) on capsule endoscopy < 270 had a lower risk of exacerbation without additional treatment. This study investigated prognostic predictors in patients undergoing capsule endoscopy and determined the optimal LS cut-off value.

METHODS

In a retrospective single-center study, 102 patients with Crohn's disease who underwent capsule endoscopy were reviewed. We reviewed the clinical course and the patients' characteristics, Crohn's Disease Activity Index, laboratory findings, LS, and Prognostic Nutritional Index (PNI) for factors potentially associated with Crohn's disease-related emergency hospitalization. Subsequently, we prospectively enrolled 66 patients with Crohn's disease and analyzed clinical outcomes according to these factors.

RESULTS

In the retrospective study, LS ≥ 270 and PNI < 45 were identified as independent predictors of Crohn's disease-related emergency hospitalization with hazard ratios of 9.48 and 3.01, respectively. Even in patients with LS ≥ 270, cumulative hospitalization rates decreased after intervention based on capsule endoscopy findings. The prospective study confirmed that patients with LS ≥ 270 or PNI < 45 had a significantly higher risk of Crohn's disease-related emergency hospitalization and that additional treatment reduced the risk of relapse.

CONCLUSIONS

LS and PNI are the best available prognostic predictors in patients with Crohn's disease without gastrointestinal stenosis and can guide decisions on treatment escalation. Patients with LS ≥ 270 and PNI < 45 were at increased risk for exacerbation, and additional treatments should be considered for this group.

The Diagnostic Usefulness of Circulating Profile of Extracellular Matrix Components: Sulfated Glycosaminoglycans (sGAG), Hyaluronan (HA) and Extracellular Part of Syndecan-1 (sCD138) in Patients with Crohn's Disease and Ulcerative Colitis

The described research focused on the diagnostic usefulness of sulfated glycosaminoglycans (sGAG), hyaluronan (HA), and extracellular part of syndecan-1 (sCD138) as new markers related to extracellular matrix (ECM) remodeling in the intestine during the two most common forms of inflammatory bowel diseases (IBD), i.e., ulcerative colitis (UC) and Crohn’ disease (CD). Inflammatory markers belonging to ECM components were assessed in serum of patients with IBD using an immunoenzymatic method (HA and sCD138) and a method based on the reaction with dimethylmethylene blue (sulfated GAG). Measurements were carried out twice: at baseline and after one year of therapy with prednisone (patients with CD) or adalimumab (patients with UC). No quantitative changes were observed in serum sGAG, HA, and sCD138 concentrations between patients newly diagnosed with CD and the healthy group. In the case of patients with UC, the parameter which significantly differentiated healthy subjects and patients with IBD before biological therapy was HA. Significant correlation between serum HA level and inflammation activity, expressed as Mayo score, was also observed in patients with UC. Moreover, the obtained results have confirmed that steroid therapy with prednisone significantly influenced the circulating profile of all examined ECM components (sGAG, HA, and sCD138), whereas adalimumab therapy in patients with UC led to a significant change in only circulating sGAG levels. Moreover, the significant differences in serum HA levels between patients with UC and CD indicate that quantification of circulating HA may be useful in the differential diagnosis of CD and UC.

The Use of Fecal Calprotectin Testing in Paediatric Disorders: A Position Paper of the European Society for Paediatric Gastroenterology and Nutrition Gastroenterology Committee

OBJECTIVES

The aim of the study was to review the evidence regarding the clinical use and value of fecal calprotectin (FC) measurements in different gastrointestinal disorders in children.

METHODS

A literature search was conducted in the PubMed, MEDLINE, EMBASE, and Cochrane databases until October 31, 2019. Subtopics were identified and each assigned to individual authors.

RESULTS

A total of 28 recommendations were voted on using the nominal voting technique. Recommendations are given related to sampling, measurement methods, and results interpretation. The 14 authors anonymously voted on each recommendation using a 9-point scale (1 strongly disagree to 9 fully agree). Consensus was considered achieved if at least 75% of the authors voted 6, 7, 8, or 9.

CONCLUSIONS

Consensus was reached for all recommendations. Limitations for the use of FC in clinical practice include variability in extraction methodology, performance of test kits as well as the need to establish local reference ranges because of the influence of individual factors, such as age, diet, microbiota, and drugs. The main utility of FC measurement at present is in the diagnosis and monitoring of inflammatory bowel disease (IBD) as well as to differentiate it from functional gastrointestinal disorders (FAPDs). FC, however, has neither utility in the diagnosis of infantile colic nor to differentiate between functional and organic constipation. A rise in FC concentration, may alert to the risk of developing necrotizing enterocolitis and help identifying gastrointestinal involvement in children with Henoch-Schönlein purpura. FC measurement is of little value in Cow's Milk Protein Allergy, coeliac disease (CD), and cystic fibrosis. FC does neither help to distinguish bacterial from viral acute gastroenteritis (AGE), nor to diagnose Helicobacter Pylori infection, small intestinal bacterial overgrowth (SIBO), acute appendicitis (AA), or intestinal polyps.

A Review of Selected IBD Biomarkers: From Animal Models to Bedside

Inflammatory bowel disease (IBD) is a dysregulated inflammatory condition induced by multiple factors. The etiology of IBD is largely unknown, and the disease progression and prognosis are variable and unpredictable with uncontrolled disease behavior. Monitoring the status of chronic colitis closely is challenging for physicians, because the assessment of disease activity and severity require invasive methods. Using laboratory biomarkers may provide a useful alternative to invasive methods in the diagnosis and management of IBD. Furthermore, patients with ulcerative colitis or Crohn’s disease are also at risk of developing cancer. Annual colonoscopies can help lower the risk for developing colorectal cancer. However, laboratory biomarkers may also be helpful as non-invasive indicators in predicting treatment responses, improving prognosis, and predicting possible tumors. This review addresses selected laboratory biomarkers (including ANCA, chitinase 3-like 1, S100A12/RAGE, calprotectin, and TNF/TNFR2), which are identified by utilizing two well-accepted animal models of colitis, dextran sodium sulfate-induced and T cell receptor alpha knockout colitis models. In addition to being useful for monitoring disease severity, these biomarkers are associated with therapeutic strategies. The factors may regulate the initiation and perpetuation of inflammatory factors in the gut.

Ustekinumab Pharmacokinetics and Exposure Response in a Phase 3 Randomized Trial of Patients With Ulcerative Colitis

BACKGROUND & AIMS

The efficacy of antibody-based therapeutics depends on their pharmacokinetics. The pharmacokinetic and exposure response profiles of ustekinumab, a monoclonal antibody against interleukin 12/interleukin 23, are known in patients with Crohn's disease, yet there are few data from patients with ulcerative colitis. We characterized ustekinumab's pharmacokinetics, exposure response, and optimal serum concentrations in patients with ulcerative colitis.

METHODS

We collected data from 2 phase 3 trials (1 induction and 1 maintenance), in which patients with moderate to severe ulcerative colitis received an intravenous induction dose of ustekinumab (130 mg, n = 320; or approximately 6 mg/kg, n = 322). Responders were assigned randomly to groups that received subcutaneous maintenance ustekinumab (90 mg) every 8 weeks (n = 176) or 12 weeks (n = 172), or placebo (n = 175). We evaluated the association between ustekinumab concentration and efficacy, serum based on clinical effects (Mayo score), histologic features, and inflammation (measurement of C-reactive protein, fecal calprotectin, and fecal lactoferrin), as well as safety (infections, serious infections, and serious adverse events), during induction and maintenance therapy. Optimal serum concentrations of ustekinumab were identified using receiver operating characteristic curve analyses.

RESULTS

In patients with ulcerative colitis, dose-proportional serum concentrations of ustekinumab, unaffected by prior biologic or concomitant immunomodulator therapy, reached steady state by the second maintenance dose; the median trough concentration for dosing every 8 weeks was approximately 3-fold that of dosing every 12 weeks. Serum concentrations were associated with clinical and histologic features of efficacy and normalization of inflammation markers. The week-8 concentration threshold for induction of response was 3.7 μg/mL. A steady-state trough serum concentration of 1.3 μg/mL or higher was associated with a higher rate of clinical remission compared with patients who had lower serum concentrations. Serum concentrations of ustekinumab were not associated with infections, serious infections, or serious adverse events.

CONCLUSIONS

In an analysis of data from 2 phase 3 trials of patients with ulcerative colitis, we found that serum concentrations of ustekinumab were proportional to dose, unaffected by prior biologic or concomitant immunomodulator therapies, associated with clinical and histologic efficacy and markers of inflammation, and were not associated with safety events at doses evaluated. Ustekinumab pharmacokinetics are consistent between patients with Crohn's disease vs ulcerative colitis.

Faecal calprotectin in inflammatory bowel diseases: a review focused on meta-analyses and routine usage limitations

A growing body of evidence has been published about the usefulness of measuring calprotectin in faecal samples (FCAL) in inflammatory bowel disease (IBD) assessment, including diagnosis, monitoring of disease activity and relapse prediction. Several systematic reviews with meta-analyses compiling studies for each particular clinical setting have been carried out in recent years. Most of these were focused on the use of FCAL in IBD diagnosis and showed a relevant role for this marker in selecting patients with gastrointestinal symptoms who would not need a further examination by endoscopy. Although a lesser number of meta-analyses have been performed on the use of FCAL as a surrogate marker of disease activity, a close correlation between FCAL and endoscopic activity of IBD has been shown. With respect to the predictive capacity of FCAL for IBD relapse, a single meta-analysis published indicates that this role is more limited. Furthermore, FCAL thresholds vary considerably depending on the clinical setting and, what is more concerning, among different commercially available assays due to a lack of FCAL concentration interchangeability. Here, we summarise recent publications about the role and limitations of FCAL in IBD, with a special focus on meta-analyses, and give an overview of alternative faecal biomarkers.

Comparison of the Nancy Index With Continuous Geboes Score: Histological Remission and Response in Ulcerative Colitis

BACKGROUND AND AIMS

Evidence has been supporting that histological activity of ulcerative colitis [UC] has relevance for the prediction of clinical outcomes in UC patients, such as clinical relapse. In this study, we aimed to compare two histological indexes-the continuous Geboes score [GS] and the Nancy index [NI] -regarding their definitions of histological remission and response, and to determine the ability of faecal calprotectin [FC] levels to discriminate between these histological statuses according to the NI.

METHODS

A large cohort of UC patients [N = 422] who were previously enrolled in other studies was analysed.

RESULTS

GS and NI were shown to be strongly correlated [correlation coefficient: 0.882, p <0.001], indicating high accordance in the classification of patients as having/not having histological remission and response. FC levels moderately correlated with NI regarding these histological statuses [correlation coefficient: 0.481, p <0.001], moderately predicted the absence of remission defined by NI >0 {area under the curve (AUC) 0.667 (95% confidence interval [CI] 0.609-0.724)}, and were good predictors of the absence of histological response defined by NI >1 (AUC 0.825 [95% CI 0.777-0.872]). The optimal FC cut-offs determined to predict the NI-defined histological remission and response were 91 μg/g and 106 μg/g, when maximising the negative predictive value [NPV].

CONCLUSIONS

Due to the higher applicability of the NI, this study encourages the systematic use of this histological index to assess histological remission and response in UC patients.

Fecal Lactoferrin for Assessment of Inflammatory Bowel Disease Activity: A Systematic Review and Meta-Analysis

OBJECTIVE

Persistent disease activity is associated with a poor prognosis in inflammatory bowel disease (IBD) patients. Therefore, monitoring of IBD activity can avoid the poor prognosis. Serum biomarkers reflect a summation of systemic host responses rather than being specific for intestinal inflammation. And endoscopic monitoring is invasive, costly, and time consuming. The objective of our study was to perform a meta-analysis evaluating the diagnostic accuracy of fecal lactoferrin (FL) in assessing IBD activity.

METHODS

We systematically searched the databases from inception to May 2018 that evaluated IBD activity. The methodological quality of each study was assessed according to the Quality Assessment of Diagnostic Accuracy Studies checklist. The extracted data were pooled using a summary receiver operating characteristic curve model. Random-effects model was used to summarize the diagnostic odds ratio, sensitivity, specificity, positive likelihood ratio, and negative likelihood ratio.

RESULTS

Ten studies comprising 773 IBD patients were included in the meta-analysis. The pooled sensitivity and specificity values for assessing ulcerative colitis (UC) activity were 0.81 [95% confidence interval (CI), 0.64-0.92] and 0.82 (95% CI, 0.61-0.93), respectively. And the pooled sensitivity and specificity values for assessing Crohn's disease (CD) activity were 0.82 (95% CI, 0.73-0.88) and 0.71 (95% CI, 0.63-0.78), respectively. The diagnostic performance of the FL assay in the UC patients appeared to be superior to that in the CD patients.

CONCLUSION

Our meta-analysis has found that FL is an inexpensive, simple, stable, and useful screening marker with high sensitivity and modest specificity for assessing IBD activity, appearing to have greater ability to evaluate UC rather than CD.

Fecal Calprotectin, CRP and Leucocytes in IBD Patients: Comparison of Biomarkers With Biopsy Results

Background

This study aimed to compare fecal calprotectin (FC) levels with other commonly used parameters as part of patient care during evaluation for inflammatory bowel disease (IBD).

Methods

We recruited adult IBD patients with ulcerative colitis (UC) and Crohn's disease (CD) and compared the results of the patient's biopsy results (i.e., inflamed versus noninflamed) for six sites (i.e., ileum, ascending colon, transverse colon, descending colon, sigmoid colon, rectum) with concentrations of C-reactive protein (CRP), total leucocytes and fecal calprotectin (FC).

Results

We found that FC was significantly elevated in a concentration-dependent manner that correlated with the number of active inflammation sites reported in biopsy. Although CRP and leucocyte measurements trended upwards in line with inflammation reported from biopsy, the results were highly variable and highlighted poor reliability of these biomarkers for indicating IBD inflammation.

Conclusions

These results strongly suggest that FC correlates best with biopsy reports and is a superior marker than CRP and leucocytes.

S100A12 in Digestive Diseases and Health: A Scoping Review

Calgranulin proteins are an important class of molecules involved in innate immunity. These members of the S100 class of the EF-hand family of calcium-binding proteins have numerous cellular and antimicrobial functions. One protein in particular, S100A12 (also called EN-RAGE or calgranulin C), is highly abundant in neutrophils during acute inflammation and has been implicated in immune regulation. Structure-function analyses reveal that S100A12 has the capacity to bind calcium, zinc, and copper, processes that contribute to nutritional immunity against invading microbial pathogens. S100A12 is a ligand for the receptor for advanced glycation end products (RAGE), toll-like receptor 4 (TLR4), and CD36, which promote cellular and immunological pathways to alter inflammation. We conducted a scoping review of the existing literature to define what is known about the association of S100A12 with digestive disease and health. Results suggest that S100A12 is implicated in gastroenteritis, necrotizing enterocolitis, gastritis, gastric cancer, Crohn's disease, irritable bowel syndrome, inflammatory bowel disease, and digestive tract cancers. Together, these results reveal S100A12 is an important molecule broadly associated with the pathogenesis of digestive diseases.

Comparing the Continuous Geboes Score With the Robarts Histopathology Index: Definitions of Histological Remission and Response and their Relation to Faecal Calprotectin Levels

BACKGROUND AND AIMS

The histological status of ulcerative colitis [UC] patients in clinical and endoscopic remission has gained space as an important prognostic marker and a key component of disease monitoring. Our main aims were to compare two histological indexes-the continuous Geboes score [GS] and the Robarts Histopathology index [RHI]-regarding their definitions of histological remission and response, and the ability of faecal calprotectin [FC] levels to discriminate between these statuses.

METHODS

This was an analysis of three prospective cohorts including 422 patients previously enrolled in other studies.

RESULTS

The two continuous scores [GS and RHI] were shown to be significantly correlated [correlation coefficient of 0.806, p < 0.001] and particularly close regarding their definition of histological response: 95% and 88% of all patients classified as having/not having [respectively] histological response according to RHI also did so according to GS. Moreover, median FC levels in patients with histological response were lower than those in patients without histological response [GS: 73.00 vs 525.00, p < 0.001; RHI: 73.50 vs 510.00, p < 0.001]; a similar trend was observed when FC levels of patients in histological remission were compared to those of patients with histological activity [GS: 76.00 vs 228.00, p < 0.001; RHI: 73.50 vs 467.00, p < 0.001]. FC levels allowed us to exclude the absence of histological remission [according to RHI] and absence of histological response [according to RHI and GS], with negative predictive values varying from 82% to 96%. However, optimization of the FC cut-off to exclude the absence of histological remission, as for the continuous GS, falls within values that resemble those of the healthy population.

CONCLUSION

The continuous GS and RHI histological scores are strongly correlated in their definitions of histological response. An absence of histological remission could only be excluded at physiological levels of FC.

Faecal calprotectin as a diagnostic marker of inflammatory bowel disease in patients with gastrointestinal symptoms: meta-analysis

Colonoscopy is the standard medical procedure to identify inflammatory bowel disease (IBD) in patients with gastrointestinal symptoms. Noninvasive measurement of faecal calprotectin concentration may replace colonoscopy in this indication. The study aimed to assess efficacy of faecal calprotectin as a diagnostic marker of IBD in patients with symptoms suggestive of such diagnosis. Meta-analysis of diagnostic accuracy studies was performed. Cochrane, EMBASE and MEDLINE databases were searched until December 2018. Inclusion criteria comprised experimental and observational studies, adults with gastrointestinal symptoms, calprotectin as index and colonoscopy as reference test, presence of data on/enabling the calculation of diagnostic accuracy parameters. For each study, sensitivity and specificity of faecal calprotectin were analysed as bivariate data. Nineteen studies were identified. The total number of patients was 5032. Calculated pooled sensitivity and specificity were 0.882 [95% confidence interval (CI), 0.827-0.921] and 0.799 (95% CI, 0.693-0.875), respectively. Following faecal calprotectin incorporation in the diagnostic work-up of 100 people with suspected IBD, 18 non-IBD patients will have a colonoscopy performed and one patient with the disease will not be referred for this examination. Faecal calprotectin concentration measurement is a useful screening test to rule out IBD, at the same time reducing the need for colonoscopy by 66.7%.

Variability of Faecal Calprotectin in Inflammatory Bowel Disease Patients: An Observational Case-control Study

BACKGROUND AND AIMS

Several factors have been reported to affect faecal calprotectin [FC] values, and significant variation in FC concentrations has been observed in inflammatory bowel disease [IBD] patients. We aimed to evaluate FC variability in IBD patients, and to assess the robustness of a single stool punch.

METHODS

This is a single-centre observational case-control study. Disease activity was assessed using endoscopic and clinical activity scores, as well as C-reactive protein levels. Stool samples were collected twice within a 1 to 6 days interval, and FC was measured on punches and homogenates by fluorometric enzyme immunocapture assay.

RESULTS

In all, 260 stool samples were collected from 120 patients. Intrastool variability was low, with an intraclass correlation coefficient for single measures between three punches from a single stool sample of 0.91, and median coefficient of variation [CV] of 17%. CV of two stool samples a few days apart [intra-individual variability] were significantly higher [p <0.01] with median CV of 36%. FC standard deviations correlated with mean FC levels either for intrastool or for intra-individual variability, with a Spearman's coefficient of rank correlation of 0.85 and 0.78, respectively [p <0.01]. Disease type, location, activity, and FC levels did not influence variability.

CONCLUSIONS

A single stool punch is reliable for FC measurement, considering that intrastool variability is low. Intra-individual variability a few days apart is significantly higher. Therefore, decision-making strategies based on single measurements should consider this variability, to determine the minimum optimal variation to be achieved, rather than a cut-off, especially in high FC levels.

Galectin-3 Regulates Indoleamine-2,3-dioxygenase-Dependent Cross-Talk between Colon-Infiltrating Dendritic Cells and T Regulatory Cells and May Represent a Valuable Biomarker for Monitoring the Progression of Ulcerative Colitis

Galectin-3 regulates numerous biological processes in the gut. We investigated molecular mechanisms responsible for the Galectin-3-dependent regulation of colon inflammation and evaluated whether Galectin-3 may be used as biomarker for monitoring the progression of ulcerative colitis (UC). The differences in disease progression between dextran sodium sulphate-treated wild type and Galectin-3-deficient mice were investigated and confirmed in clinical settings, in 65 patients suffering from mild, moderate, and severe colitis. During the induction phase of colitis, Galectin-3 promoted interleukin-1β-induced polarization of colonic macrophages towards inflammatory phenotype. In the recovery phase of colitis, Galectin-3 was required for the immunosuppressive function of regulatory dendritic cells (DCs). Regulatory DCs in Galectin-3:Toll-like receptor-4:Kynurenine-dependent manner promoted the expansion of colon-infiltrated T regulatory cells (Tregs) and suppressed Th1 and Th17 cell-driven colon inflammation. Concentration of Galectin-3 in serum and stool samples of UC patients negatively correlated with clinical, endoscopic, and histological parameters of colitis. The cutoff serum values of Galectin-3 that allowed the discrimination of mild from moderate and moderate from severe colitis were 954 pg/mL and 580 pg/mL, respectively. Fecal levels of Galectin-3 higher than 553.44 pg/mL indicated attenuation of UC. In summing up, Galectin-3 regulates the cross-talk between colon-infiltrating DCs and Tregs and represents a new biomarker for monitoring the progression of UC.

Different pattern of stool and plasma gastrointestinal damage biomarkers during primary and chronic HIV infection

Introduction

Primary HIV infection (PHI) is the initial phase after HIV acquisition characterized by high viral replication, massive inflammatory response and irreversible immune-damage, particularly at the gastrointestinal level. In this study we aimed to characterize the dynamics of gastrointestinal damage biomarkers during the different phases of HIV infection and assess their association with HIV-disease markers and their accuracy to differentiate PHI from chronic HIV infection (CHI).

Methods

PHI-individuals (n = 57) were identified as HIV-seronegative/HIV-RNA positive and were followed up for one year at the Manhiça District Hospital in Mozambique. Ten plasma and 12 stool biomarkers were quantified by Luminex or ELISA and levels were compared to CHI-naive (n = 26), CHI on antiretroviral-treatment (ART; n = 30) and HIV-uninfected individuals (n = 58). Regression models adjusted by time point were used to estimate the association of the biomarkers with HIV-disease markers. Receiver operating curves were compared for the best accuracy to distinguish PHI from CHI.

Results

Soluble (s)CD14 was significantly associated with the CD4/CD8 ratio (P < 0.05) and viremia levels (P < 0.0001) during PHI. Plasma zonulin and stool lactoferrin were significantly higher in PHI as compared to CHI-individuals (P < 0.05). Plasma zonulin demonstrated the best accuracy to identify PHI among HIV-infected individuals (AUC = 0.85 [95% CI 0.75–0.94]). Using a cutoff value of plasma zonulin ≥ 8.75 ng/mL the model identified PHI with 87.7% sensitivity (95% CI 76.3–94.9) and 69.2% specificity (95% CI 48.2–85.7). An adjusted multivariate model including age, plasma zonulin and sCD14 further increased the classification performance (AUC = 0.92 [95% CI 0.86–0.99]).

Conclusions

While the stool biomarkers did not provide any predictive ability to distinguish PHI from CHI-individuals, plasma sCD14 and zonulin were significantly associated with HIV-disease markers and PHI identification, respectively. These inflammatory biomarkers may be useful to monitor changes in gastrointestinal integrity during HIV infection.

Usefulness of transabdominal ultrasonography for assessing ulcerative colitis: a prospective, multicenter study

BACKGROUND

Transabdominal ultrasonography (US) has been reported to be a useful tool for evaluating ulcerative colitis (UC) although with less well-established data than for Crohn's disease. This prospective multicenter study aimed to establish the usefulness of US compared with colonoscopy (CS) for assessing disease extent and activity of UC.

METHODS

Altogether, 173 patients with UC were prospectively enrolled, among whom 156 were eligible for this study. All patients underwent US and CS within 2 days at five facilities. We divided the colon into six segments and examined each segment and the rectum using US and CS. US severity was graded 1-4 regarding bowel wall thickness, stratification, and ulceration. CS severity was also graded 1-4 according to Matts' endoscopic classification. Concordance between US and CS grades for all colonic segments was analyzed using kappa statistics. US and CS findings were also compared with the clinical disease activity index (CAI) and histological grade using Spearman's correlation coefficient.

RESULTS

There was moderate concordance between US and CS grades in all colonic segments (weighted κ = 0.55, p < 0.001). Concordance was rated moderate for each colonic segment but only slight for the rectum. The US grade was significantly correlated with the CAI score (r = 0.40, p < 0.001) and histological grade (r = 0.35, p < 0.001).

CONCLUSIONS

This prospective multicenter study showed moderate concordance between US and CS for assessing the disease activity of UC. Hence, US may be used more generally for evaluating UC in daily clinical practice.

IBDoc Canadian User Performance Evaluation

BACKGROUND

Fecal calprotectin (FC) is a stool biomarker that has been shown to be sensitive and specific for mucosal inflammation in patients with inflammatory bowel disease (IBD). The test is limited by the requirement for patients to collect and return stool samples. A home-based FC test may improve test adherence. The aim of this study is to evaluate the usability of the IBDoc, a home-based FC measuring test, and to determine the accuracy of results compared with traditional lab-based ELISA values.

METHODS

Patients were prospectively enrolled from 3 tertiary sites across Canada between May and August 2017. Patients completed a questionnaire establishing ease-of-use of the IBDoc. Patients completed a FC measurement using the IBDoc, and results were compared with an ELISA-determined FC measurement on the same stool sample.

RESULTS

Sixty-one participants were enrolled in the study (29 CD, 32 UC). Seventy-nine percent of patients (48 of 61) agreed that the IBDoc was easy to use, with 85% (52 of 61) of patients strongly agreeing that they were willing use the home kit in the future. The IBDoc and ELISA measurement comparison showed an 88% agreement across all values. There were no false positives or negatives using qualitative comparison.

CONCLUSIONS

The home-based IBDoc FC measuring test is acceptable to patients and correlates extremely well with the standard ELISA-determined FC value. The IBDoc enables clinicians to more easily adopt a treat-to-target approach, improve long-term outcomes, and patients' quality of life with IBD. This study is registered at ClinicalTrials.gov, number NCT03408249.

Update on C-reactive protein and fecal calprotectin: are they accurate measures of disease activity in Crohn's disease?

'Treat-to-target' paradigms in Crohn's disease (CD) directed at suppressing intestinal inflammation require accurate and reliable measures of disease activity. Although endoscopy has traditionally been considered a gold standard, cost, complexity, resource limitations, and invasiveness are important limitations. Hence, substantial interest exists for non-invasive serum and fecal biomarkers, namely C-reactive protein (CRP) and fecal calprotectin (FC), in the diagnosis, monitoring, and treatment of CD. Areas covered: We review the evidence for using serum CRP and FC in distinguishing patients with CD from those with irritable bowel syndrome, categorizing disease activity among patients with an established diagnosis of CD, predicting the likelihood of treatment response, identifying asymptomatic patients in medically or surgically induced remission who are at risk for disease relapse, and as treatment targets. Expert commentary: Accurate interpretation of CRP and FC is dependent on several factors including the clinical context, the performance characteristics of the assay, the specified test cut-offs, and the pre-test probability of disease. Emerging evidence indicates that CRP and FC are valuable adjuncts for the management of CD in specific circumstances described in this review.