Elevated Faecal Calprotectin Levels are a Reliable Non-Invasive Screening Tool for Small Bowel Crohn's Disease in Patients Undergoing Capsule Endoscopy

Faecal calprotectin increases the diagnostic yield in patients with suspected small bowel disease - a multicenter retrospective cohort study

AIM OF THE STUDY

Diagnosing small bowel pathology is challenging, and the diagnostic yield of small bowel capsule endoscopy is highly variable. Faecal calprotectin is a non-invasive intestinal inflammation marker that could be used as a selection tool to identify patients who might benefit from small bowel capsule endoscopy and increase its diagnostic yield. This study aimed to investigate the value of faecal calprotectin in detecting small bowel lesions in an unselected patient population.

METHODS

We performed a retrospective analysis of consecutive patients who underwent small bowel capsule endoscopy at the University Hospital Basel and the University Medical Clinic Cantonal Hospital Baselland, Switzerland, between 2010 and 2018. Patients without faecal calprotectin testing were excluded from the analysis. The primary endpoint was the presence of a clinically significant small bowel finding.

RESULTS

Patients with positive faecal calprotectin results were more likely to have small bowel findings (66.7% vs 39.4%; P = 0.007). The optimal faecal calprotectin cut-off to identify clinically significant small bowel lesions was 63 μg/g with 78.3% (95% confidence interval: 66.7-87.9) sensitivity, 47.9% (33.3-62.8) specificity, 1.50 (1.1-2.0) positive and 0.45 (0.3-0.8) negative likelihood ratios, 68.4% (61.6-74.4) positive and 60.5% (47.3-72.4) negative predictive values, and 65.0% overall accuracy. Faecal calprotectin performed best in patients with suspected inflammatory bowel disease, with 66.7% (48.2-82.0) sensitivity, 70.6% (44.0-89.7) specificity, 2.27 (1.0-4.9) positive and 0.47 (0.3-0.8) negative likelihood ratios, 81.5% (67.0-90.5) positive and 54.5% (39.7-68.6) negative predictive values, and 71.4% overall accuracy.

CONCLUSION

Faecal calprotectin testing increases the diagnostic yield of small bowel capsule endoscopy and may help identify patients at risk of small bowel disease.

Usefulness of ultrasonography for small intestinal evaluations in pediatric Crohn's disease

BACKGROUND

Small bowel capsule endoscopy (SBCE) for Crohn's disease is useful; however, its use has some limitations, such as invasiveness when endoscopic assistance is required in patients who cannot swallow the capsule, and the burden of interpretation on a physician. In contrast, intestinal ultrasonography (IUS) is a non-invasive modality for children. The purpose of this study is to evaluate the accuracy of IUS for pediatric patients with established Crohn's disease.

METHODS

Small bowel capsule endoscopy and IUS findings from the same period in pediatric patients with established Crohn's disease were analyzed retrospectively. First, we compared the Lewis score (LS), small bowel endoscopic activity, and IUS findings by small bowel wall thickness (SBWT) and mesenteric lymph node size (MLNS). Second, we compared the performance of IUS findings with those of some biomarkers.

RESULTS

In 22 procedures, SBWT and MLNS were correlated with LS (r = 0.52, P < 0.05, and r = 0.45, P < 0.05, respectively). Small bowel wall thickness, erythrocyte sedimentation rate, and fecal calprotectin levels had the highest accuracy (81.8%, 81.8%, and 81.8%, respectively). The combination of SBWT and MLNS had the highest positive predictive value and negative predictive value (100% and 83.3%, respectively).

CONCLUSIONS

Intestinal ultrasonography findings, including SBWT and MLNS, are useful for monitoring small bowel lesions in pediatric patients with established Crohn's disease. We suggest first evaluating small bowel inflammation by IUS in pediatric patients with Crohn's disease before SBCE because IUS is less invasive than SBCE.

Small-Bowel Capsule Endoscopy-Optimizing Capsule Endoscopy in Clinical Practice

The small bowel is the longest organ within the gastrointestinal tract. The emergence of small bowel capsule endoscopy (SBCE) over the last 20 years has revolutionized the investigation and diagnosis of small bowel pathology. Its utility as a non-invasive and well-tolerated procedure, which can be performed in an outpatient setting, has made it a valuable diagnostic tool. The indications for SBCE include obscure gastrointestinal bleeding, small bowel Crohn's disease, and, less frequently for screening in polyposis syndromes, celiac disease, or other small bowel pathology. Currently, there are several small bowel capsules on the market from different manufacturers; however, they share many technological features. The European Society of Gastrointestinal Endoscopy (ESGE) only recently developed a set of key quality indicators to guide quality standards in this area. Many of the technical aspects of capsule endoscopy still feature a degree of uncertainty in terms of optimal performance. Incomplete studies due to slow transit through the bowel, poor imaging secondary to poor preparation, and the risk of capsule retention remain frustrations in its clinical utility. Capsule review is a time-consuming process; however, artificial intelligence and machine learning offer opportunities to improve this. This narrative review examines our current standing in a number of these aspects and the potential to further the application of SBCE in order to maximize its diagnostic utility.

Diagnostic Accuracy of Fecal Calprotectin for the Detection of Small Bowel Crohn's Disease through Capsule Endoscopy: An Updated Meta-Analysis and Systematic Review

Background/Aims

The diagnosis of small bowel Crohn's disease with negative ileocolonoscopic findings has been challenging. Fecal calprotectin (FC) has been used to detect colonic inflammation, but its efficacy for detecting small bowel inflammation is less established. We performed an updated meta-analysis to evaluate the diagnostic accuracy of FC to detect active small bowel inflammation observed during capsule endoscopy.

Methods

We conducted a systematic literature search for studies that evaluated the correlation between small bowel inflammation and FC in patients with suspected/established Crohn's disease. We calculated the pooled sensitivity, specificity, and diagnostic odds ratios (DORs) and constructed hierarchical summary receiver operating characteristic curves for FC cutoffs of 50, 100, and 200 μg/g.

Results

Fourteen studies were eligible for the final analysis. The DORs of all FC cutoffs were significant. The highest DOR was observed at 100 μg/g (sensitivity, 0.73; specificity, 0.73; and DOR, 7.89) and was suggested as the optimal diagnostic cutoff. If we analyzed only studies that included patients with suspected Crohn's disease, the DOR was 8.96. If we analyzed only studies that included patients with a Lewis score ≥135 as a diagnostic criterion for active disease, the DOR was 10.90.

Conclusions

FC has significant diagnostic accuracy for detecting small bowel inflammation, and an FC cutoff of 100 μg/g can be used as a tool to screen for small bowel Crohn's disease.

The utility of faecal and urine biomarkers for small bowel diseases

PURPOSE OF REVIEW

Small bowel diseases pose a unique diagnostic and management challenge and often requires tertiary specialist referral. The use of biomarkers may provide a cheap, noninvasive tool to assess the small bowel in terms of diagnosis, offering a better way to triage referrals and select patients for early management. This review looks at the most recent evidence behind the use of several faecal and urine biomarkers for small bowel diseases.

RECENT FINDINGS

Faecal calprotectin shows the most promise, with evidence to support its role in predicting relapse postsurgery and monitoring treatment response in patients with Crohn's disease. A faecal calprotectin less than 50 μg/g may also be used as a cut-off to triage further investigation. Faecal lactoferrin also appears promising as a marker of small bowel inflammation. A positive faecal immunohistochemistry test precapsule may help to prioritize referrals for obscure bleeding.

SUMMARY

The use of biomarkers in the diagnosis and management of small bowel disease is still controversial and remains unclear. More studies are required to further develop their potential and before societal guidelines can be developed to direct their appropriate use in clinical practice.

Capsule endoscopy - Recent developments and future directions

INTRODUCTION

Capsule endoscopy (CE) is an established modality in the diagnostic algorithm of small bowel (SB) pathology. Its use has expanded for investigation of upper and lower gastrointestinal diseases with similar prototypes.

AREAS COVERED

This review covers the role and recent advances of CE, as a non-invasive investigative tool.

EXPERT OPINION

The use of upper gastrointestinal CE is useful in patients who require surveillance for varices particularly in the current era of the COVID-19 pandemic. It has also shown high accuracy in the detection of upper gastrointestinal hemorrhage in patients presenting with a suspicion of hemorrhage. Findings on CE help to guide further management by device-assisted enteroscopy. The data on colon CE suggest comparable diagnostic accuracy to colonoscopy for polyp detection; however, more evidence is required in the high-risk group. Crohn's CE has become an integral part of the management of patients with Crohn's disease offering a comparative assessment tool post escalation of therapy. Artificial intelligence within CE has demonstrated similar if not better diagnostic yield compared to the human with a significantly shorter reading time. Artificial intelligence is likely to be in-built within CE reading platforms over the next few years minimizing reporting time and human error.

Small bowel capsule endoscopy: where do we stand after 20 years of clinical use?

Small bowel capsule endoscopy (SBCE) was introduced into clinical practice almost 20 years ago and, nowadays, it is an essential tool for the study of the small bowel. SBCE allows a radiation-free examination of the entire mucosal surface of the small bowel with high-quality images, limited invasivity and a good safety profile. Nevertheless, the main limitation of SBCE is the lack of any possible direct therapeutic intervention. Indications for SBCE have evolved throughout the years, from "old" ones such as suspected small bowel bleeding (still the main indication for SBCE) to newer ones such as refractory celiac disease, hereditary polyposis syndromes and Crohn's disease. Thus, nowadays SBCE has a key role in the diagnostic algorithms in many conditions. Furthermore, the introduction in the SBCE field of cutting-edge technologies, as artificial intelligence systems, is likely to shorten the reading time making SBCE even more effective and easy to perform. Preliminary data are extremely promising and solid evidence is being gathered by current studies.

How Do We Treat Inflammatory Bowel Diseases to Aim For Endoscopic Remission?

Crohn's disease and ulcerative colitis are heterogeneous conditions which may manifest with 1 or more of a constellation of abnormal symptoms, elevated biomarkers, and/or objective evidence of inflammation on endoscopic or cross-sectional evaluation. Whilst resolution of symptoms and restoration of quality of life is the primary goal for patients following a disease flare, there may be discordance between resolution of symptoms, biomarkers, and endoscopy. Increased emphasis is placed on the achievement of endoscopic remission, given it is associated with improved outcomes and reduction in hospitalization and surgeries. As the therapeutic armamentarium for inflammatory bowel disease does not achieve remission in all patients, there is greater emphasis on repetitive interval-based assessment of disease activity with sequential algorithmic treatment adjustments until endoscopic remission is achieved, in a so-called treat-to-target approach. We review the role of symptoms, biomarkers, imaging and endoscopy within treat-to-target algorithms and provide a practical guidance to their use in clinical practice.

Is fecal calprotectin an accurate marker in the management of Crohn's disease?

Although lacking validated cutoff values, fecal calprotectin (FC), besides C-reactive protein, is considered the standard test for assessing disease activity in Crohn's disease (CD). The aim of the present review is to provide a general overview of the literature addressing the role of FC in the clinical and endoscopic assessment of disease activity in CD, seeking correlations with capsule endoscopy, response to therapy, prediction of relapse, and postoperative recurrence. A systematic search of the literature up to September 2019 was performed using Medline, Embase, and the Cochrane Library. Only papers written in English concerning FC in adult patients affected by CD were included. Pediatric studies, in vitro studies, animal studies, studies on blood/serum samples, and studies analyzing FC in ulcerative colitis or in both CD and ulcerative colitis were excluded. Out of 713 citations, 65 eligible studies were identified. FC showed high accuracy in the assessment of intestinal inflammation and response to therapy, in particular in colonic disease, thus proving a good surrogate marker for these aims. FC is useful in identifying patients at high risk for endoscopic relapse or postoperative recurrence, for optimizing or downstage therapy. Unfortunately, FC performs less well in small bowel CD. FC is an effective fecal marker in the management of CD patients, optimizing the use of endoscopic procedures. Owing to its diagnostic accuracy, FC may represent a cornerstone of the "treat-to-target" management strategy of CD patients.

Should We Divide Crohn's Disease Into Ileum-Dominant and Isolated Colonic Diseases?

Crohn's disease (CD) is an inflammatory bowel disease that can involve any region of the gastrointestinal tract. First described in 1932 as terminal ileitis or regional enteritis, it predominately involves the ileum with or without colonic involvement. Isolated colonic CD was first described in 1960 and since then the phenotypic classification of CD has evolved to stratify patients into isolated ileal, ileocolonic, or isolated colonic involvement. In the current review we evaluate the published literature regarding differences in epidemiology, natural history, pathogenesis, response to therapy, and disease monitoring, when stratified by disease location. Based on the available evidence consideration could be given to a new classification for CD, which splits it into ileum dominant (isolated ileal and ileocolonic) and isolated colonic disease. This may allow for a more optimized approach to clinical care and scientific research for CD.

The role of small bowel endoscopy for Crohn's disease

PURPOSE OF REVIEW

The review discusses the roles of small bowel capsule endoscopy and deep enteroscopy in patients with Crohn's disease. It highlights recent advances in the field and identifies areas where evidence is lacking.

RECENT FINDINGS

Small bowel capsule endoscopy has an important role in the follow-up of patients with Crohn's disease after escalation of therapy and in the postoperative assessment period following surgical resection. Device-assisted enteroscopy offers the therapeutic advantage of small bowel dilatation, which may result in a reduction in the number of surgical resections required, thus avoiding long-term complications, such as short bowel syndrome and malabsorption.

SUMMARY

Capsule endoscopy has an established role in the diagnosis and management of small bowel Crohn's disease. It is used in the setting of suspected Crohn's disease when ileocolonoscopy is negative and for the assessment of extent of small bowel disease in established Crohn's disease. It is relatively well tolerated because of the provision of patency capsule endoscopy to minimize the risk of inadvertent capsule retention. Device-assisted enteroscopy aids with the diagnosis of Crohn's disease as it enables histology to be taken from inflamed areas within the small bowel. Therapeutic procedures can be carried out during device-assisted enteroscopy including dilatation of Crohn's disease-related strictures and retrieval of retained capsules.

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.