Noninvasive Tests for Inflammatory Bowel Disease: A Meta-analysis

Diagnosis and management of inflammatory bowel disease

Inflammatory bowel disease (IBD) is a chronic and relapsing immune-mediated disease of the gastrointestinal tract with a gradually increasing global incidence and prevalence. A prolonged course of IBD leads to a decline in patient quality of life and the creation of a substantial economic burden on society. Owing to the lack of specific diagnostic markers, the diagnosis of IBD still needs a gold standard based on a combination of clinical manifestations, imaging, laboratory, and endoscopic results. Accordingly, the current goals of IBD treatment are to alleviate clinical symptoms and reduce recurrence rates. Therefore, it is imperative to develop a standard set of procedures to diagnose and treat IBD. In this review, we summarize prominent and emerging studies, outline classical and contemporary approaches to diagnosing and managing IBD, and integrate multiple guidelines. Furthermore, we propose the possibility of establishing an early and comprehensive diagnostic workflow and personalized management strategy in the future. We aim to enhance the quality and standardization of diagnostic and treatment procedures for IBD.

Inflammatory bowel disease biomarkers

Inflammatory bowel disease (IBD) is characterized as chronic inflammation in the gastrointestinal tract, which includes two main subtypes, Crohn's disease and ulcerative colitis. Endoscopy combined with biopsy is the most effective way to establish IBD diagnosis and disease management. Imaging techniques have also been developed to monitor IBD. Although effective, the methods are expensive and invasive, which leads to pain and discomfort. Alternative noninvasive biomarkers are being explored as tools for IBD prognosis and disease management. This review focuses on novel biomarkers that have emerged in recent years. These serological biomarkers and microRNAs could potentially be used for disease management in IBD, thereby decreasing patient discomfort and morbidity.

Association between body mass index and fecal calprotectin levels in children and adolescents with irritable bowel syndrome

Irritable bowel syndrome (IBS) is a common pediatric functional gastrointestinal disorder. It is characterized by recurrent abdominal pain and changes in bowel habits and is more prevalent in obese patients. We investigated the association between obesity and IBS in pediatric patients through fecal calprotectin testing. Patients under 18 years of age with IBS who underwent fecal calprotectin testing from January 2015 through April 2020 were retrospectively investigated. The patients were divided into groups based on body mass index (BMI): group I (BMI < 85th percentile) and group II (BMI ≥ 85th percentile). Group II was divided into group IIa, overweight (85th percentile ≤ BMI < 95th percentile), and group IIb, obese (BMI ≥ 95th percentile). Among 277 included patients, 202 (72.9%) were in group I, and 75 (27.1%) were in group II (mean calprotectin levels, 75.60 ± 103.48 vs 45.89 ± 66.57 µg/g, respectively; P = .006). There were significant differences in mean calprotectin levels between groups I and IIa (75.60 ± 103.48 vs 45.45 ± 63.38 µg/g, respectively; P = .028) and groups I and IIb (75.60 ± 103.48 vs 46.22 ± 69.59 µg/g, respectively; P = .025). There was a significant difference in mean calprotectin levels between groups I and II (85.69 ± 142.13 vs 32.04 ± 28.17 µg/g, respectively; P = .029) among patients between 6 and 12 years of age but not among adolescents aged between 12 and 18 years (P = .139). Fecal calprotectin was lower when moderate-to-severe fatty livers were observed by ultrasound compared with normal livers (68.52 ± 97.22 vs 18.53 ± 18.56 µg/g, respectively; P = .017). Fecal calprotectin levels were higher in normal-weight pediatric IBS patients than in their obese counterparts, and this difference was more prominent in younger patients. In young children, IBS symptoms are thought to be influenced more by factors other than intestinal inflammation.

Diagnostic Utility of Non-invasive Tests for Inflammatory Bowel Disease: An Umbrella Review

Background

This study aims to consolidate evidence from published systematic reviews and meta-analyses evaluating the diagnostic performances of non-invasive tests for inflammatory bowel disease (IBD) in various clinical conditions and age groups.

Methods

Two independent reviewers systematically identified and appraised systematic reviews and meta-analyses assessing the diagnostic utility of non-invasive tests for IBD. Each association was categorized as adults, children, and mixed population, based on the age ranges of patients included in the primary studies. We classified clinical scenarios into diagnosis, activity assessment, and predicting recurrence.

Results

In total, 106 assessments from 43 reviews were included, with 17 non-invasive tests. Fecal calprotectin (FC) and fecal lactoferrin (FL) were the most sensitive for distinguishing IBD from non-IBD. However, anti-neutrophil cytoplasmic antibodies (ANCA) and FL were the most specific for it. FC and FL were the most sensitive and specific tests, respectively, to distinguish IBD from irritable bowel syndrome (IBS). Anti-Saccharomyces cerevisiae antibodies (ASCA), IgA, were the best test to distinguish Crohn’s disease (CD) from ulcerative colitis (UC). Interferon-γ release assay was the best test to distinguish CD from intestinal tuberculosis (ITB). Ultrasound (US) and magnetic resonance enterography (MRE) were both sensitive and specific for disease activity, along with the high sensitivity of FC. Small intestine contrast ultrasonography (SICUS) had the highest sensitivity, and FC had the highest specificity for operative CD recurrence.

Conclusion

In this umbrella review, we summarized the diagnostic performance of non-invasive tests for IBD in various clinical conditions and age groups. Clinicians can use the suggested non-invasive test depending on the appropriate clinical situation in IBD patients.

A Healthcare Physician Can Be Trained to Perform Intestinal Ultrasound in Children With Inflammatory Bowel Disease

OBJECTIVES

Training healthcare physicians to perform intestinal ultrasound (IUS) during outpatient visits with equal accuracy as radiologists could improve clinical management of IBD patients. We aimed to assess whether a healthcare-physician can be trained to perform IUS, with equal accuracy compared with experienced radiologists in children with iBD, and to assess inter-observer agreement.

METHODS

Consecutive children, 6 to 18 years with IBD or suspicion of IBD, who underwent ileo-colonoscopy were enrolled. iUS was performed independently by a trained healthcare-physician and a radiologist in 1 visit. Training existed of an international training curriculum for IUS. Operators were blinded for each other's IUS, and for the ileocolonoscopy. Difference in accuracy of IUS by the healthcare-physician and radiologist was assessed using areas under the ROC curve (AUROC). Inter-observer variability was assessed in terminal ileum (TI), transverse colon (TC) and descending-colon (DC), for disease activity (ie, bowel wall thickness [BWT] >2 mm with hyperaemia or fat-proliferation, or BWT >3 mm).

RESULTS

We included 73 patients (median age 15, interquartile range [IQR]:13-17, 37 [51%] female, 43 [58%] with Crohn disease). AUROC ranged between 0.71 and 0.81 for the healthcare-physician and between 0.67 and 0.79 for radiologist (P  > 0.05). Inter-observer agreement for disease activity per segment was moderate (K: 0.58 [SE: 0.09], 0.49 [SE: 0.12], 0.52 [SE: 0.11] respectively for TI, TC, and DC).

CONCLUSIONS

A healthcare- physician can be trained to perform IUS in children with IBD with comparable diagnostic accuracy as experienced radiologists. The interobserver agreement is moderate. Our findings support the usage of IUS in clinical management of children with IBD.

Association between autism spectrum disorder and inflammatory bowel disease: A systematic review and meta-analysis

Children with autism spectrum disorder (ASD) are frequently diagnosed with co-occurring medical conditions including inflammatory bowel disease (IBD). To investigate the association, we conducted a systematic review registered in PROSPERO (ID:CRD42021236263) with a random-effects meta-analysis. We searched PubMed, Embase, and PsycInfo (last search on January 25, 2021), and manually searched relevant publications. We included observational studies measuring the association between ASD and IBD. The primary outcome was the association (odds ratio, OR) between ASD and later development of IBD. Sensitivity analyses were conducted by quality, confounding adjustment, and study design. We performed meta-regression analyses and assessed heterogeneity, publication bias, and quality of studies with the Newcastle-Ottawa Scale. Overall, we included six studies consisting of eight datasets, including over 11 million participants. We found that ASD was significantly associated with subsequent incident IBD (any IBD, OR = 1.66, 95% confidence interval[CI] = 1.25-2.21, p < 0.001; ulcerative colitis, OR = 1.91, 95%CI = 1.41-2.6, p < 0.001; Crohn's disease, OR = 1.47, 95%CI = 1.15-1.88, p = 0.002). ASD and IBD were also associated regardless of temporal sequence of diagnosis (any IBD, OR = 1.57, 95%CI = 1.28-1.93, p < 0.001; ulcerative colitis, OR = 1.7, 95%CI = 1.36-2.12, p < 0.001; Crohn's disease, OR = 1.37, 95%CI = 1.12-1.69, p = 0.003). Sensitivity analyses confirmed the findings of the main analysis. Meta-regression did not identify any significant moderators. Publication bias was not detected. Quality was high in four datasets and medium in four. In conclusion, our findings highlight the need to screen for IBD in individuals with ASD, and future research should identify who, among those with ASD, has the highest risk of IBD, and elucidate the shared biological mechanisms between ASD and IBD.

Study of the changes in immune indexes, pathogenic characteristics and related risk factors in children with viral diarrhea

BACKGROUND

Infectious diarrhea is a serious hazard to children under 5 years old. The causative microorganisms are mostly viruses and bacteria, with different treatment required for each. Currently, early clinical differential diagnosis is difficult with the available testing methods. Therefore, new and more sensitive indicators of viral infection reflect the early stage of infection are needed.

METHODS

We collected blood samples and fresh fecal samples from 100 children diagnosed with viral diarrhea who were treated in the outpatient clinic at Changzhou Tumor Hospital Affiliated to Soochow University from January 2018 to December 2020. The levels of interleukin-2 (IL-2), IL-6, tumor necrosis factor-α (TNF-α), and C-reactive protein (CRP) in serum, the erythrocyte sedimentation rate (ESR) and enterovirus were measured and compared with those in a matched healthy control group. Patients' demographic and risk factor data were collected by interviewing parents.

RESULTS

The mean levels of IL-2, IL-6, TNF-α, ESR, and CRP in the viral diarrhea group were higher than those in the healthy control group. Except for IL-6, the differences in inflammatory factors between groups were statistically significant (P<0.05). Human rotavirus (HRV) infection was the highest. Children's hand-washing habits, weekly disinfection of toys, and vaccination were protective factors for viral diarrhea, and indoor flies were an important risk factor (P<0.05).

CONCLUSIONS

The serum levels of markers were significantly increased in the children with viral diarrhea. HRV was the main pathogen, and mixed infections existed. Infection control requires hand washing, regular disinfection of toys, vaccination and preventing indoor flies.

Effect of faecal calprotectin testing on referrals for children with chronic gastrointestinal symptoms in primary care: study protocol for a cluster randomised controlled trial

INTRODUCTION

Children with chronic gastrointestinal symptoms are frequently seen in primary care, yet general practitioners (GPs) often experience challenges distinguishing functional gastrointestinal disorders (FGID) from organic disorders. We, therefore, aim to evaluate whether a test strategy that includes point-of-care testing (POCT) for faecal calprotectin (FCal) can reduce the referral rate to paediatric specialist care among children with chronic gastrointestinal symptoms. The study findings will contribute to improving the recommendations on FCal use among children in primary care.

METHODS AND ANALYSIS

In this pragmatic cluster randomised controlled trial, we will randomise general practices into intervention and control groups. The intervention group will use FCal-POCT when indicated, after completing online training about its indication, interpretation and follow-up as well as communicating an FGID diagnosis. The control group will test and treat according to Dutch GP guidelines, which advise against FCal testing in children. GPs will include children aged 4-18 years presenting to primary care with chronic diarrhoea and/or recurrent abdominal pain. The primary outcome will be the referral rate for children with chronic gastrointestinal symptoms within 6 months after the initial assessment. Secondary outcomes will be evaluated by questionnaires completed at baseline and at 3- and 6-month follow-up. These outcomes will include parental satisfaction and concerns, gastrointestinal symptoms, impact of symptoms on daily function, quality of life, proportion of children with paediatrician-diagnosed FGID referred to secondary care, health service use and healthcare costs. A sample size calculation indicates that we need to recruit 158 GP practices to recruit 406 children.

ETHICS AND DISSEMINATION

The Medical Research Ethics Committee (MREC) of the University Medical Center Groningen (The Netherlands) approved this study (MREC number: 201900309). The study results will be made available to patients, GPs, paediatricians and laboratories via peer-reviewed publications and in presentations at (inter)national conferences.

TRIAL REGISTRATION NUMBER

The Netherlands Trial Register: NL7690 (Pre-results).

Fecal Calprotectin Is Elevated in HIV and Related to Systemic Inflammation

BACKGROUND

Fecal calprotectin (FC), a biomarker of gastrointestinal (GI) inflammation, is used in the diagnosis and management of inflammatory bowel disease. HIV infection severely damages gut-associated lymphoid and epithelial tissues leading to GI inflammation that drives systemic inflammation and increases subsequent risk of comorbidities. For the first time, we compared FC concentrations by HIV and antiretroviral therapy (ART) status and determined the relationship to systemic inflammation.

METHODS

People with and without HIV were enrolled and underwent a comprehensive clinical and laboratory assessment. Stool samples were collected, and FC was measured by enzyme-linked immunosorbent assay ELISA. Plasma biomarkers of inflammation were also measured.

RESULTS

One hundred one participants with HIV (83 ART-treated and 18 ART-naive) and 89 uninfected controls were enrolled. There were no significant differences between ART-naive and ART-treated participants, but both HIV groups had significantly higher FC concentrations than controls when FC was considered as a continuous variable or by cut-offs used in inflammatory bowel disease. The highest median and largest proportion of participants with FC >100 µg/g were seen in ART-naive, followed by ART-treated and then controls. Among HIV participants, FC concentrations were positively associated with high-sensitivity C-reactive protein, soluble tumor necrosis factor receptor II, and soluble vascular cellular adhesion molecule and inversely associated with CD4 counts.

CONCLUSIONS

FC concentrations are elevated in HIV regardless of ART status. ART and immune reconstitution seem to reduce FC but not to concentrations seen in uninfected controls. Our results suggest a role for FC as a noninvasive surrogate measurement of GI inflammation and associated systemic inflammation in HIV.

A Practical Guide for Faecal Calprotectin Measurement: Myths and Realities

BACKGROUND AND AIMS

Faecal calprotectin [FC] is a valid and non-invasive marker of mucosal inflammation. It is widely used both in clinical trials and in daily clinical practice for patients with inflammatory bowel diseases, but currently no accepted standardization for FC testing is available. Our primary aim here was to provide a clinician's guide containing all the practical information on FC measurement in order to avoid any confounding factors, to minimize intra- and inter-individual variability in dosage, and to ensure a better and adequate interpretation of the results.

METHODS

We conducted a detailed search of the scientific literature in the PubMed/MEDLINE, EMBASE and Cochrane databases up to January 2020 to find all relevant and available articles on pre-analytical and analytical phases of FC measurement.

RESULTS

FC testing is a multi-step procedure consisting of a pre-analytical phase aimed to collect and process the stool sample and a subsequent analytical phase of FC measurement. Several factors can influence test results determining false positives or false negatives. Importantly, this faecal marker is mostly used for patient follow-up and as a predictor of treatment response. For this reason, any altered data may affect the physicians' decisions, negatively impacting on patient management.

CONCLUSIONS

This review provides for the first time practical advice to minimize dosage variability, although further dedicated studies are needed to compare commercially available tests and identify the best tools for the most precise and accurate FC measurement.

Primary care faecal calprotectin testing in children with suspected inflammatory bowel disease: a diagnostic accuracy study

OBJECTIVE

To determine the diagnostic accuracy of calprotectin to diagnose inflammatory bowel disease (IBD) in children in whom general practitioners (GPs) suspected IBD.

DESIGN

Prospective observational cohort study of a new calprotectin-based primary care referral pathway.

SETTING

48 GP practices and gastroenterology secondary care services at the Royal Devon and Exeter NHS Foundation Trust in the South-West of England, UK.

PATIENTS

195 children aged between 4 and 18 years referred on the pathway between January 2014 and August 2017 for investigation of gastrointestinal symptoms were included.

INTERVENTIONS

Primary-care-driven faecal calprotectin testing. Primary and secondary care records over 12 months from the point of calprotectin testing were used as the reference standard.

MAIN OUTCOME MEASURES

Diagnostic accuracy of calprotectin testing to detect IBD.

RESULTS

7% (13/195) tested patients were diagnosed with IBD. Using our prespecified cut-off of 100 µg/g, calprotectin had a diagnostic accuracy of 91% (95% CI 86% to 95%) with a sensitivity for distinguishing IBD from non-IBD of 100% (95% CI 75% to 100%), a specificity of 91% (95% CI 85% to 94%), a positive predictive value of 43% (95% CI 25% to 63%) and a negative predictive value of 100% (95% CI 98% to 100%). Calprotectin testing had no effect on the time to diagnosis, but a negative test contributed to saved referrals and was associated with fewer diagnostic tests in secondary care.

CONCLUSIONS

Calprotectin testing of children with suspected IBD in primary care accurately distinguishes IBD from a functional gut disorder, reduces secondary care referrals and associated diagnostic healthcare utilisation.

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.

Test Strategies to Predict Inflammatory Bowel Disease Among Children With Nonbloody Diarrhea

OBJECTIVES

We evaluated 4 diagnostic strategies to predict the presence of inflammatory bowel disease (IBD) in children who present with chronic nonbloody diarrhea and abdominal pain.

METHODS

We conducted a prospective cohort study including 193 patients aged 6 to 18 years who underwent a standardized diagnostic workup in secondary or tertiary care hospitals. Each patient was assessed for symptoms, C-reactive protein (>10 mg/L), hemoglobin (<-2 SD for age and sex), and fecal calprotectin (≥250 μg/g). Patients with rectal bleeding or perianal disease were excluded because the presence of these findings prompted endoscopy regardless of their biomarkers. Primary outcome was IBD confirmed by endoscopy or IBD ruled out by endoscopy or uneventful clinical follow-up for 6 months.

RESULTS

Twenty-two of 193 (11%) children had IBD. The basic prediction model was based on symptoms only. Adding blood or stool markers increased the AUC from 0.718 (95% confidence interval [CI]: 0.604-0.832) to 0.930 (95% CI: 0.884-0.977) and 0.967 (95% CI: 0.945-0.990). Combining symptoms with blood and stool markers outperformed all other strategies (AUC 0.997 [95% CI: 0.993-1.000]). Triaging with a strategy that involves symptoms, blood markers, and calprotectin will result in 14 of 100 patients being exposed to endoscopy. Three of them will not have IBD, and no IBD-affected child will be missed.

CONCLUSIONS

Evaluating symptoms plus blood and stool markers in patients with nonbloody diarrhea is the optimal test strategy that allows pediatricians to reserve a diagnostic endoscopy for children at high risk for IBD.

Fecal calprotectin in the pediatric population: a 2020 update

Calprotectin is a calcium and zinc-binding protein, formed by a hetero complex of S100A8 and S100A9 proteins, which belong to the S-100 protein family consisting in more than 20 different proteins with a tissue-specific expression pattern. This protein is secreted extracellularly from stimulated neutrophils or released by cell disruption or death. The presence of calprotectin in feces quantitatively relates to neutrophil migration toward the gastrointestinal (GI) tract; thus, it represents a useful marker of intestinal inflammation. Fecal calprotectin (FC) has been proven largely useful for determining the inflammatory origin of GI symptoms differentiating between organic and non-organic diseases. Indeed, increased FC levels are also seen in gastroenteritis, microscopic colitis, polyps, malignancies and cystic fibrosis. To date, there are many evidences regarding usefulness in the detection of fecal calprotectin for the management of gastrointestinal disorders, both in children and adults but, especially in the pediatric population, still clear indications for its use are lacking. Its incorporation in primary care reduces the risk of missing an organic disease and facilitates the indication for expensive and invasive investigations as colonoscopy. We herein review and discuss the last evidence on the usefulness of FC in children, with its current indications and future prospective.

Analytical and clinical performance of the fully-automated LIAISONXL calprotectin immunoassay from DiaSorin in IBD patients

Objectives

Distinction between inflammatory bowel disease (IBD) and irritable bowel syndrome (IBS) based on clinical symptoms is often difficult. In this study we assessed the performance of the fully-automated calprotectin immunoassay from DiaSorin in IBD diagnosis and follow-up and compared it to the EliA calprotectin 2 immunoassay.

Design

and Methods: The calprotectin immunoassay from DiaSorin run on the LIAISONXL was analytically and clinically validated and compared to the EliA calprotectin 2 immunoassay from Thermo Fisher Scientific run on the ImmunoCAP250. Five patient groups were measured (n ​= ​303): IBD: ulcerative colitis (UC) and Crohn’s disease (CD); non-IBD: IBS, other gastrointestinal diseases and controls (healthy patients with no gastrointestinal disease).

Results

The calprotectin immunoassay of DiaSorin showed good analytical performance with frozen samples. The presence of blood in the stool can interfere with the measurement of calprotectin. Patients suffering from IBD (UC or CD) showed significant higher concentrations of fecal calprotectin compared to controls (UC:710 ​± ​921 ​mg/kg; CD:967 ​± ​1243 ​mg/kg; controls:11±8 ​mg/kg) using DiaSorin’s immunoassay. The remaining non-IBD groups showed no significant difference compared to controls. Follow-up patients (n ​= ​9) showed a significant decrease in fecal calprotectin after treatment. At 50 ​mg/kg cut-off value, the negative predictive value for DiaSorin’s immunoassay was 96% and the positive predictive value 83% (sensitivity of 95% and specificity of 86%).

Conclusions

The lack of standardization contributes to the numerical differences between the two methods, but the qualitative conclusions do not differ. DiaSorin’s calprotectin immunoassay can be used both to distinguish between IBD and non-IBD patients as well as for follow-up of IBD patients.

•

New calprotectin immunoassay has a short sample preparation time and is easy to use.

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DiaSorin’s immunoassay can be used to distinguish between high and low risk IBD patients, as opposed to IBS.

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Differences observed between immunoassays are due to lack of standardization.

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Blood in the stool can effect the calprotectin measurement.

Fecal Calprotectin in Combination With Standard Blood Tests in the Diagnosis of Inflammatory Bowel Disease in Children

Introduction: Fecal calprotectin (FC) is a useful non-invasive screening test but elevated levels are not specific to inflammatory bowel disease (IBD). The study aimed to evaluate the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of FC alone or FC in combination with other standard blood tests in the diagnosis of IBD. Methods: Children aged <17 years who had FC (normal range <50 μg/g) measured and underwent endoscopy over 33 months in Christchurch, New Zealand were identified retrospectively (consecutive sampling). Medical records were reviewed for patient final diagnoses. Results: One hundred and two children were included; mean age was 12.3 years and 53 were male. Fifty-eight (57%) of the 102 children were diagnosed with IBD: 49 with Crohn's disease, eight with ulcerative colitis and one with IBD-unclassified. FC of 50 μg/g threshold provided a sensitivity of 96.6% [95% confident interval (CI) 88.3-99.4%] and PPV of 72.7% (95% CI 61.9-81.4%) in diagnosing IBD. Two children with IBD however were found to have FC <50 μg/g. Sensitivity in diagnosing IBD was further improved to 98.3% (95% CI 90.7-99.1%) when including FC >50 μg/g or elevated platelet count. Furthermore, PPVs in diagnosing IBD improved when FC at various thresholds was combined with either low albumin or high platelet count. Conclusion: Although FC alone is a useful screening test for IBD, a normal FC alone does not exclude IBD. Extending FC to include albumin or platelet count may improve sensitivity, specificity, PPV and NPV in diagnosing IBD. However, prospective studies are required to validate this conclusion.

Biomarker discovery in inflammatory bowel diseases using network-based feature selection

Reliable identification of Inflammatory biomarkers from metagenomics data is a promising direction for developing non-invasive, cost-effective, and rapid clinical tests for early diagnosis of IBD. We present an integrative approach to Network-Based Biomarker Discovery (NBBD) which integrates network analyses methods for prioritizing potential biomarkers and machine learning techniques for assessing the discriminative power of the prioritized biomarkers. Using a large dataset of new-onset pediatric IBD metagenomics biopsy samples, we compare the performance of Random Forest (RF) classifiers trained on features selected using a representative set of traditional feature selection methods against NBBD framework, configured using five different tools for inferring networks from metagenomics data, and nine different methods for prioritizing biomarkers as well as a hybrid approach combining best traditional and NBBD based feature selection. We also examine how the performance of the predictive models for IBD diagnosis varies as a function of the size of the data used for biomarker identification. Our results show that (i) NBBD is competitive with some of the state-of-the-art feature selection methods including Random Forest Feature Importance (RFFI) scores; and (ii) NBBD is especially effective in reliably identifying IBD biomarkers when the number of data samples available for biomarker discovery is small.

Clinical value of fecal calprotectin

Inflammatory bowel disease (IBD) denotes a group of chronic incurable disorders characterized by relapsing-remitting inflammation of the gastrointestinal tract. IBD represents a growing global burden with a prevalence exceeding 0.3% in the Western world and an accelerating incidence in newly industrialized countries. The target for treating IBD has shifted in recent years from symptom control to mucosal healing (MH), which has been shown to be associated with favorable long-term outcomes. The gold standard for ascertaining MH is endoscopic assessment, but endoscopy is limited by its invasive nature, high cost, and finite availability. Surrogate biomarkers are therefore of great utility. Calprotectin, a cytosolic protein derived predominantly from neutrophils, is now widely used in this capacity. Calprotectin is found in various bodily fluids at concentrations proportional to the degree of inflammation, including in feces at levels roughly six times higher than in the blood. Fecal calprotectin (FCP) therefore reflects intestinal inflammation. Various assays, including point-of-care and home-based tests, are now available for measuring FCP. FCP is used for screening purposes, to aid in distinguishing inflammatory from non-inflammatory gastrointestinal conditions like irritable bowel syndrome (IBS), as well as in the monitoring of known IBD. The aims of this review are to provide an overview of the methods used to measure FCP and to review the evidence supporting the use of FCP in IBD, particularly as it pertains to screening, monitoring and predicting disease relapse.

Clinical usefulness of the faecal calprotectin test in suspected paediatric inflammatory bowel disease

AIM

The faecal calprotectin (FC) test is increasingly being used in clinical practice to help select children with gastrointestinal symptoms who might have inflammatory bowel disease (IBD) and benefit from endoscopies. We provide an overview of the advantages and limitations of the FC test.

METHODS

PubMed was searched for meta-analyses that had investigated the diagnostic accuracy of the FC test and the pooled sensitivity and specificity for distinguishing IBD from non-IBD patients were used to calculate likelihood ratios (LR). These were applied to practical examples to explain how easily clinicians can use the results to modify pre-test probabilities of IBD and generate post-test probabilities for IBD.

RESULTS

The positive LR and negative LR of the FC test were 2.8 and 0.015, respectively. The usefulness of the FC test depended on the pre-test probability of IBD. When the pre-test probability of IBD was low, a positive FC test did not necessarily indicate IBD. However, because of the very small negative LR, a negative FC result virtually ruled out IBD in most cases.

CONCLUSION

The FC test should not be used indiscriminately in children with gastrointestinal symptoms but should be targeted at those who are likely to have IBD.

Combining Rome III criteria with alarm symptoms provides high specificity but low sensitivity for functional gastrointestinal disorders in children

AIM

This study aimed to validate the Rome III criteria and alarm symptoms with regard to their ability to discriminate between organic and functional diagnoses in children with gastrointestinal complaints.

METHODS

We recruited 258 children aged four years to 17 years who consulted a paediatrician in secondary or tertiary care in Stockholm from January 2013 to May 2014 due to gastrointestinal complaints. A symptom questionnaire based on the official Questionnaire on Pediatric Gastrointestinal Symptoms Rome III, including questions on alarm symptoms, was used. A diagnostic review of their medical records was also carried out.

RESULTS

The reference diagnoses were organic (16%), pain-predominant functional gastrointestinal disorders (54%) and other functional diseases (30%). When the reported symptoms that fulfilled the Rome III criteria for pain-predominant functional gastrointestinal disorders were combined with an absence of alarm symptoms, they had a high specificity (0.90) for a functional diagnosis, but a low sensitivity (0.15). Alarm symptoms were equally common in patients with organic (83%) and functional diseases (80%, p = 0.66).

CONCLUSIONS

Combining the Rome III criteria and an absence of alarm symptoms from patient questionnaires had high specificity but low sensitivity when diagnosing pain-predominant functional gastrointestinal disorders in children seeking medical care for gastrointestinal complaints.

Utility of Fecal Calprotectin in Evaluation of Chronic Gastrointestinal Symptoms in Primary Care

Fecal calprotectin (FC) is a marker of intestinal inflammation. Data are limited on utility of routine FC testing in pediatric primary care. Participants 0 to 18 years old who had an FC test in the years 2010-2014 were retrospectively identified. Those with less than a year of follow-up or a prior diagnosis of inflammatory bowel disease (IBD) were excluded. In all, 84% (689/822) had normal FC; no participant with normal FC was diagnosed with IBD in the subsequent 12 months. Also, 16% (133/822) had elevated FC, and 31% of those (42/133) were diagnosed with IBD. FC values for IBD and non-IBD groups were 1084 µg/g (interquartile range [IQR] = 514.4-2000) and 27.05 µg/g (IQR = 15.6-62.6; P < .001), respectively. Abdominal pain was the primary indication. In this cohort, sensitivity of FC for IBD is 100%, and specificity is 88%. The FC test can be an excellent tool in the primary care setting to exclude IBD and avoid unnecessary referrals and colonoscopies.

Predicting inflammatory bowel disease in children with abdominal pain and diarrhoea: calgranulin-C versus calprotectin stool tests

OBJECTIVE

Calgranulin-C (S100A12) is a new faecal marker of inflammation that is potentially more specific for inflammatory bowel disease (IBD) than calprotectin, since it is only released by activated granulocytes. We compared calgranulin-C and calprotectin to see which of the two tests best predicted IBD in children with chronic abdominal pain and diarrhoea.

DESIGN

Delayed-type cross-sectional diagnostic study.

SETTING AND PATIENTS

Previously undiagnosed patients aged 6-17 years, who were seen in paediatric clinics in the Netherlands and Belgium, sent in a stool sample for analysis. Patients with a high likelihood of IBD underwent upper and lower endoscopy (ie, preferred reference test), while those with a low likelihood were followed for 6 months for latent IBD to become visible (ie, alternative reference test). We used Bayesian modelling to correct for differential verification bias.

MAIN OUTCOME MEASURES

Primary outcome was the specificity for IBD using predefined test thresholds (calgranulin-C: 0.75 µg/g, calprotectin: 50 µg/g). Secondary outcome was the test accuracy with thresholds based on receiver operating characteristics (ROC) analysis.

RESULTS

IBD was diagnosed in 93 of 337 patients. Calgranulin-C had significantly better specificity than calprotectin when predefined thresholds were used (97% (95% credible interval (CI) 94% to 99%) vs 71% (95% CI 63% to 79%), respectively). When ROC-based thresholds were used (calgranulin-C: 0.75 µg/g, calprotectin: 400 µg/g), both tests performed equally well (specificity: 97% (95% CI 94% to 99%) vs 98% (95% CI 95% to 100%)).

CONCLUSIONS

Both calgranulin-C and calprotectin have excellent test characteristics to predict IBD and justify endoscopy.

TRIAL REGISTRATION NUMBER

NCT02197780.

Serologic and fecal markers to predict response to induction therapy in dogs with idiopathic inflammatory bowel disease

Background

Little information is available of markers that assess the disease course in dogs with idiopathic inflammatory bowel disease (IBD).

Objectives

Evaluate relationship between disease severity and serum and fecal biomarkers in dogs with idiopathic IBD before and after treatment.

Animals

Sixteen dogs with idioptahic IBD and 13 healthy dogs.

Methods

Prospective case control study. Canine IBD activity index (CIBDAI) clinical score, serum concentrations of C‐reactive protein (CRP), perinuclear antineutrophil cytoplasmic antibodies (pANCA), and serum and fecal canine calprotectin (cCP) were measured before and after 21 days of treatment.

Results

Serum CRP (median 3.5 mg/L; range: 0.1‐52.4 mg/L), fecal cCP (median 92.3 μg/g; range: 0.03‐637.5 μg/g), and CIBDAI scores significantly increased in dogs with IBD before treatment compared with serum CRP (median 0.2 mg/L; range: 0.1‐11.8 mg/L; P < .001), fecal cCP (median 0.67 μg/g; range: 0.03‐27.9 μg/g; P < .001) and CIBDAI (P < .001) after treatment. No significant associations between CIBDAI scores and before or after treatment serum biomarkers. There was a significant association between fecal cCP and CIBDAI scores before treatment (rho = 0.60, P = .01). CRP and fecal cCP significantly decreased after treatment (median 3.5 mg/L v. 0.2 mg/L; P < .001 and 92.3 μg/g v. 0.67 μg/g; P = .001, respectively).

Conclusions and Clinical Importance

Our data indicate that measurement of fecal cCP concentration is a useful biomarker for noninvasive evaluation of intestinal inflammation. Dogs with severe signs of GI disease more often have abnormal markers than dogs having less severe disease.

Diagnostic delay in Canadian children with inflammatory bowel disease is more common in Crohn's disease and associated with decreased height

OBJECTIVES

To determine time to diagnosis in a paediatric inflammatory bowel disease (IBD) cohort and the relative contribution of the component intervals, and to identify factors associated with diagnostic delay.

DESIGN

Prospective cohort study SETTING: Single-centre study including children with incident IBD at the Hospital for Sick Children diagnosed between December 2013 and December 2015.

INTERVENTIONS

Time to diagnosis and its subintervals were determined and patient, disease and institutional factors were tested for associations.

RESULTS

Among 111 children, the median overall time to diagnosis was 4.5 (IQR 2.1-8.8) months. Time to diagnosis was longer in Crohn's disease (CD) than ulcerative colitis (UC) (median 6.8 (IQR 2.9-12.5) vs 2.4 (IQR 1.3-5.3) months) and patients with isolated small bowel disease. Twenty per cent of patients were diagnosed≥1 year after symptom onset (86% CD, 14% UC, p=0.003). Time from symptom onset to gastroenterology referral was the greatest contributor to overall time to diagnosis (median 2.9 (IQR 1.6-8.2) months). Height impairment was independently associated with diagnostic delay (OR 0.59, p=0.02, for height-for-age z-score (HAZ), signifying almost 70% increased odds of delay for every 1 SD decrease in HAZ). This height discrepancy persisted 1 year after diagnosis. Bloody diarrhoea was protective against delay (OR 0.28, p=0.02). The subinterval from referral to diagnosis was shorter in patients with laboratory abnormalities, particularly hypoalbuminaemia.

CONCLUSIONS

Diagnostic delay was more common in CD and associated with height impairment that persisted 1 year after presentation. The greatest contributor to time to diagnosis was time from symptom onset to referral.

Diagnostic test strategies in children at increased risk of inflammatory bowel disease in primary care

Background

In children with symptoms suggestive of inflammatory bowel disease (IBD) who present in primary care, the optimal test strategy for identifying those who require specialist care is unclear. We evaluated the following three test strategies to determine which was optimal for referring children with suspected IBD to specialist care: 1) alarm symptoms alone, 2) alarm symptoms plus c-reactive protein, and 3) alarm symptoms plus fecal calprotectin.

Methods

A prospective cohort study was conducted, including children with chronic gastrointestinal symptoms referred to pediatric gastroenterology. Outcome was defined as IBD confirmed by endoscopy, or IBD ruled out by either endoscopy or unremarkable clinical 12 month follow-up with no indication for endoscopy. Test strategy probabilities were generated by logistic regression analyses and compared by area under the receiver operating characteristic curves (AUC) and decision curves.

Results

We included 90 children, of whom 17 (19%) had IBD (n = 65 from primary care physicians, n = 25 from general pediatricians). Adding fecal calprotectin to alarm symptoms increased the AUC significantly from 0.80 (0.67–0.92) to 0.97 (0.93–1.00), but adding c-reactive protein to alarm symptoms did not increase the AUC significantly (p > 0.05). Decision curves confirmed these patterns, showing that alarm symptoms combined with fecal calprotectin produced the diagnostic test strategy with the highest net benefit at reasonable threshold probabilities.

Conclusion

In primary care, when children are identified as being at high risk for IBD, adding fecal calprotectin testing to alarm symptoms was the optimal strategy for improving risk stratification.

Unique Inflammatory Bowel Disease Phenotype of Pediatric Primary Sclerosing Cholangitis: A Single-Center Study

OBJECTIVES

In adults, primary sclerosing cholangitis (PSC), a cholestatic liver disease characterized by inflammation/fibrosis of intra/extrahepatic bile ducts, associates with a milder form of inflammatory bowel disease (IBD), particularly ulcerative colitis (UC). The pediatric PSC-IBD phenotype is less well characterized.

METHODS

We performed a retrospective, single-center study examining patients with PSC-IBD at Texas Children's Hospital between 2000 and 2015. IBD-phenotype (Modified Montreal Classification), medications, laboratory values, endoscopic records, and IBD-based hospital admissions were collected. PSC-UC phenotype was compared to UC, non-PSC patients (n = 95) from Texas Children's Hospital. Elevated gamma-glutamyl transpeptidase levels were compared to calprotectin levels and IBD-flare activity, that is, gastrointestinal symptoms resulting in office/emergency department visits or hospital admission.

RESULTS

Of 39 patients with PSC-IBD, 34 (87.2%) had UC (PSC-UC) and 5 (12.8%) had Crohn disease. Pancolitis was more common in PSC-UC than UC, non-PSC (96.3%, 64%, P = 0.0009). Patients with PSC-UC required less treatment with steroids (76.5%, 91.6%, P = 0.0326) or infliximab (8.8%, 37.9%, P = 0.0011), and fewer had at least 1 IBD-related hospital admission (32.4%, 63.2%, P = 0.0025) than UC, non-PSC. Progression to colectomy was significantly less (5.8%, 24.2%, P = 0.0223) in PSC-UC. Median diagnosis-to-colectomy time tended to be longer in PSC-UC (6.37, 2.5 years, P = 0.0792). In 2 smaller subsets, gamma-glutamyl transpeptidase did not correlate with calprotectin in PSC-UC (n = 11, P = 0.7922) and less strongly associated with IBD-flares in PSC-UC than UC, non-PSC (n = 33, n = 67; 15.2%, 41.8%, P = 0.0120).

CONCLUSIONS

Pediatric PSC appears to associate with milder pancolitic-UC. PSC and IBD activity do not appear to correlate. Our findings may provide useful information toward etiology and management of pediatric PSC-IBD.

Use of Laboratory Markers in Addition to Symptoms for Diagnosis of Inflammatory Bowel Disease in Children: A Meta-analysis of Individual Patient Data

Importance

Blood markers and fecal calprotectin are used in the diagnostic workup for inflammatory bowel disease (IBD) in pediatric patients. Any added diagnostic value of these laboratory markers remains unclear.

Objective

To determine whether adding laboratory markers to evaluation of signs and symptoms improves accuracy when diagnosing pediatric IBD.

Data Sources

A literature search of MEDLINE and EMBASE from inception through September 26, 2016. Studies were identified using indexing terms and free-text words related to child, target condition IBD, and diagnostic accuracy.

Study Selection

Two reviewers independently selected studies evaluating the diagnostic accuracy of more than 1 blood marker or fecal calprotectin for IBD, confirmed by endoscopy and histopathology or clinical follow-up, in pediatric patients with chronic gastrointestinal symptoms. Studies that included healthy controls and/or patients with known IBD were excluded.

Data Extraction and Synthesis

Individual patient data from each eligible study were requested from the authors. In addition, 2 reviewers independently assessed quality with Quality Assessment of Diagnostic Accuracy Studies-2.

Mean Outcomes and Measures

Laboratory markers were added as a single test to a basic prediction model based on symptoms. Outcome measures were improvement of discrimination by adding markers as a single test and improvement of risk classification of pediatric patients by adding the best marker.

Results

Of the 16 eligible studies, authors of 8 studies (n = 1120 patients) provided their data sets. All blood markers and fecal calprotectin individually significantly improved the discrimination between pediatric patients with and those without IBD, when added to evaluation of symptoms. The best marker-fecal calprotectin-improved the area under the curve of symptoms by 0.26 (95% CI, 0.21-0.31). The second best marker-erythrocyte sedimentation rate-improved the area under the curve of symptoms by 0.16 (95% CI, 0.11-0.21). When fecal calprotectin was added to the model, the proportion of patients without IBD correctly classified as low risk of IBD increased from 33% to 91%. The proportion of patients with IBD incorrectly classified as low risk of IBD decreased from 16% to 9%. The proportion of the total number of patients assigned to the intermediate-risk category decreased from 55% to 6%.

Conclusions and Relevance

In a hospital setting, fecal calprotectin added the most diagnostic value to symptoms compared with blood markers. Adding fecal calprotectin to the diagnostic workup of pediatric patients with symptoms suggestive of IBD considerably decreased the number of patients in the group in whom challenges in clinical decision making are most prevalent.

Evaluation of point-of-care test calprotectin and lactoferrin for inflammatory bowel disease among children with chronic gastrointestinal symptoms

BACKGROUND

Faecal calprotectin is considered to be a valid test for ruling out inflammatory bowel disease (IBD) in children with chronic gastrointestinal symptoms in specialist care. In contrast, faecal lactoferrin has higher specificity. The recent availability of both as point-of-care tests (POCTs) makes them attractive for use in primary care.

OBJECTIVE

To evaluate the test characteristics of calprotectin and lactoferrin POCTs for diagnosing IBD in symptomatic children.

METHODS

We defined two prospective cohorts of children with chronic gastrointestinal symptoms: (i) children presenting to primary care (primary care cohort); (ii) children referred for specialist care (referred cohort). Baseline POCT results were compared with the outcome of either endoscopic assessment or 12 months follow-up. Clinicians were blinded to the POCT results.

RESULTS

In the primary care cohort, none of the 114 children had IBD, and the calprotectin and lactoferrin POCTs had specificities of 0.95 (0.89-0.98) and 0.98 (0.93-0.99), respectively. In the referred cohort, 17 of the 90 children had IBD: the sensitivity of POCT calprotectin and POCT lactoferrin were both 0.94 (0.72-0.99); and the specificity was 0.93 (0.84-0.97) and 0.99 (0.92-1.00), respectively. The POCT calprotectin could reduce the referral rate by 76% and POCT lactoferrin by 81%, while missing one child with IBD (6%).

CONCLUSION

A diagnostic test strategy in primary care using a simple POCT calprotectin or lactoferrin has the potential to reduce the need for referral for further diagnostic work-up in specialist care, with a low risk of missing a child with IBD.

Diagnosis and management of inflammatory bowel disease in children

Inflammatory bowel diseases (IBD), including Crohn's disease and ulcerative colitis, are lifelong conditions that often begin in childhood. The implications of IBD are of particular importance in children because of the potential negative effects on growth, development, psychosocial function, and overall wellbeing. The key management strategy is to achieve sustained control of intestinal inflammation and monitor for potential complications of the disease and side effects of therapies. Overall, the evidence on the management of IBD in children is less extensive than in adults, but good quality multicenter studies and various guidelines and society consensus statements are available. This review summarizes the evidence on the pathophysiology, diagnosis, and approaches to management of children and adolescents with IBD.

Selecting children with suspected inflammatory bowel disease for endoscopy with the calgranulin C or calprotectin stool test: protocol of the CACATU study

INTRODUCTION

The introduction of the faecal calprotectin (FC) test to screen children with chronic gastrointestinal complaints has helped the clinician to decide whether or not to subject the patient to endoscopy. In spite of this, a considerable number of patients without inflammatory bowel disease (IBD) is still scoped. Faecal calgranulin C (S100A12) is a marker of intestinal inflammation that is potentially more specific for IBD than FC, as it is exclusively released by activated granulocytes.

OBJECTIVE

To determine whether the specificity of S100A12 is superior to the specificity of FC without sacrificing sensitivity in patients with suspected IBD.

METHODS

An international prospective cohort of children with suspected IBD will be screened with the existing FC stool test and the new S100A12 stool test. The reference standard (endoscopy with biopsies) will be applied to patients at high risk of IBD, while a secondary reference (clinical follow-up) will be applied to those at low risk of IBD. The differences in specificity and sensitivity between the two markers will be calculated.

ETHICS AND DISSEMINATION

This study is submitted to and approved by the Medical Ethics Review Committee of the University Medical Center Groningen (the Netherlands) and the Antwerp University Hospital (Belgium). The results will be disseminated through a peer-reviewed publication, conference presentation and incorporation in the upcoming National Guideline on Diagnosis and Therapy of IBD in Children.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT02197780 .

Difficulties in the Diagnosis and Management of Functional or Recurrent Abdominal Pain in Children

Recurrent abdominal pain is a frequent pathology seen in the pediatric gastroenterology practice. In fact, most children with abdominal pain symptoms have functional disorders of the gastrointestinal tract. A focused medical history, comprehensive physical examination, and minimal testing are often enough to establish the diagnosis. The presence of red flags such as rectal bleeding, bilious vomiting, fever, and arthralgia should alert providers as well as direct further diagnostic and therapeutic plans. When patients show no red flags after a complete physical examination, providing the family with information about the pathophysiology and explaining the psychosocial model of pain can help to decrease anxiety around the pain symptoms. This article discusses the challenges in diagnosing and managing abdominal pain in children. [Pediatr Ann. 2016;45(11):e388-e393.].

Diagnostic Accuracy of Fecal Calprotectin for Pediatric Inflammatory Bowel Disease in Primary Care: A Prospective Cohort Study

PURPOSE

In specialist care, fecal calprotectin (FCal) is a commonly used noninvasive diagnostic test for ruling out inflammatory bowel disease (IBD) in children with chronic gastrointestinal symptoms. The aim of this study was to evaluate the diagnostic accuracy of FCal for IBD in symptomatic children in primary care.

METHODS

We studied 2 prospective cohorts of children with chronic diarrhea, recurrent abdominal pain, or both: children initially seen in primary care (primary care cohort) and children referred to specialist care (referred cohort). FCal (index test) was measured at baseline and compared with 1 of the 2 reference standards for IBD: endoscopic assessment or 1-year follow-up. Physicians were blinded to FCal results, and values greater than 50 μg/g feces were considered positive. We determined specificity in the primary care cohort and sensitivity in the referred cohort.

RESULTS

None of the 114 children in the primary care cohort ultimately received a diagnosis of IBD. The specificity of FCal in the primary care cohort was 0.87 (95% CI, 0.80-0.92). Among the 90 children in the referred cohort, 17 (19%) ultimately received a diagnosis of IBD. The sensitivity of FCal in the referred cohort was 0.99 (95% CI, 0.81-1.00).

CONCLUSIONS

The findings of this study suggest that a positive FCal result in children with chronic gastrointestinal symptoms seen in primary care is not likely to be indicative of IBD. A negative FCal result is likely to be a true negative, which safely rules out IBD in children in whom a primary care physician considers referral to specialist care.