The diagnostic accuracy of faecal calprotectin and small bowel capsule endoscopy and their correlation in suspected isolated small bowel Crohn's disease

Advancements in Gastrointestinal System Biomarkers

The requirement for diagnostic surgical operations of gastrointestinal system diseases significantly decreases with the help of proper diagnostic tools. These modalities are also beneficial for identifying postoperative complications, allowing us to diagnose them in earlier stages, and increasing the postoperative survival rates. Biomarkers are considered an integral part of diagnostic examinations. Developments of biomarkers used for diagnosing and treating abdominal diseases are essential for improving our capabilities in non-invasive monitoring. In this chapter, we review both the novel and the routine biomarkers in the diagnosis and follow-up of gastrointestinal system diseases.

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.

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 role of small-bowel endoscopy in inflammatory bowel disease: an updated review on the state-of-the-art in 2021

The impact of small-bowel (SB) capsule endoscopy and device-assisted enteroscopy on clinical practice, since their introduction 2 decades ago, has been remarkable. These disruptive technologies have transformed the investigation and management of SB pathology and now have a firmly established place in guidelines and clinical algorithms. Furthermore, recent years have witnessed innovations, driven by the demand of new goals in the management of inflammatory bowel disease (IBD), such as mucosal healing and evolving strategies based on tight monitoring and accelerated escalation of care. These developments in SB endoscopy have also been paralleled by refinement in dedicated radiological SB imaging technologies. This updated review highlights the current state of the art and more recent innovations with a focus on their role in IBD.

From terminal ileitis to Crohn's disease: how capsule endoscopy is crucial to diagnosis

BACKGROUND AND AIMS

Terminal ileitis is a common condition and may be associated with a wide variety of diseases, mostly Crohn's disease. Although small bowel capsule endoscopy (SBCE) is a valuable diagnostic tool for small-bowel diseases, data regarding its diagnostic impact on isolated terminal ileitis are sparse. The aim of this study was to evaluate the diagnostic value of SBCE for isolated terminal ileitis detected during ileocolonoscopy and to assess predictive factors for Crohn's disease diagnosis.

METHODS

This is a retrospective study including consecutive patients undergoing SBCE after diagnosis of terminal ileitis without colonic mucosal abnormalities on ileocolonoscopy between January 2016 and September 2019.

RESULTS

This included 102 patients with isolated terminal ileitis on ileocolonoscopy. Positive findings on SBCE were found in 82.4% of patients. After performing SBCE, 61.8% of patients had a final diagnosis, being Crohn's disease the most common (34.3%), followed by NSAIDs enteropathy (12.7%). Extraintestinal manifestations (P = 0.003), weight loss (P = 0.02), abnormal imaging (P = 0.04) and positive SBCE findings (P = 0.001) were independently associated with Crohn's disease diagnosis. Regarding SBCE, presence of proximal small-bowel disease (P = 0.02), diffuse findings (P = 0.002) and moderate to severe inflammatory activity (Lewis score ≥ 790) (P < 0.001) were independently associated with Crohn's disease diagnosis.

CONCLUSION

SBCE is a valuable tool that should be systematically used in patients with isolated terminal ileitis on ileocolonoscopy, since it revealed a high diagnostic yield, supporting a definite diagnosis in almost two-thirds of patients, and Crohn's disease diagnosis in approximately one-third of patients. A diagnosis of Crohn's disease should be considered when a patient with terminal ileitis on ileocolonoscopy shows proximal involvement, diffuse findings and/or moderate to severe inflammatory activity on SBCE.

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.

Characterization of Mucosal Lesions in Crohn's Disease Scored With Capsule Endoscopy: A Systematic Review

Background and Aims: There is little agreement on the nomenclature and description of Crohn's disease (CD) lesions that can be found in the small and large bowel using capsule endoscopy (CE). We performed a systematic review to identify mucosal lesions that have been described using CE in CD, in both the small bowel and colon, with the aim to make propositions to homogenize such descriptions.

Methods: A systematic literature search was conducted using Embase, Medline (OvidSP), and Cochrane Central on August 6, 2019. Clinical studies providing nomenclature and descriptions for small bowel and colonic inflammatory lesions using CE in CD were selected for data collection.

Results: In total, 851 articles were included for abstract screening out of which 219 were analyzed for full-text review. Twenty-two articles were selected for data extraction. Seven items, accompanied by clear descriptions, were found for the small bowel: i.e., ulcer, erosion, aphthoid lesion, edema, fissure, cobblestone appearance, and villous atrophy. No studies were found describing inflammatory items using CE in colonic CD.

Conclusions: The most frequently described CD lesions using CE were ulcers and erosions. Subjective interpretation of CE inflammatory findings plays an important role. Based on our findings, a range of suggestions regarding items and descriptions is made that might form the basis of a pan-enteric CE activity index.

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.

Fecal Calprotectin as a Selection Tool for Small Bowel Capsule Endoscopy in Suspected Crohn's Disease

BACKGROUND

Small bowel capsule endoscopy (SBCE) is a firstline examination in patients with suspected Crohn's disease (CD) after negative ileocolonoscopy. Fecal calprotectin (FC) is a noninvasive marker of intestinal inflammation. The aim of this study was to evaluate the predictive value of FC in inflammatory activity detected by SBCE in patients with suspected CD.

METHODS

This is a retrospective study including patients who underwent SBCE for suspected CD between March 2015 and October 2016. FC was measured within 1 week of SBCE. Inflammatory activity at SBCE was considered significant when the Lewis score (LS) was ≥135. FC correlation with LS was assessed using the Spearman correlation. The diagnostic accuracy of FC for significant inflammatory activity at SBCE was calculated by the area under the receiver operating characteristic curve (AUC).

RESULTS

Seventy-five patients were included: 52 females (69.3%), with a mean age of 37 years. SBCE detected significant inflammatory activity (LS ≥ 135) in 42 patients (56%), and FC was positively correlated to LS (rank correlation = 0.56; P < 0.001). The AUC of FC was 0.854 for significant inflammatory activity (LS ≥ 135). For values of FC ≥100 µg/g, an LS ≥135 was found in 33 of 37 patients (89.2%, P < 0.001), corresponding to a sensitivity, specificity, positive predictive value, and negative predictive value of 78.6%, 87.9%, 89.2%, and 76.3%, respectively.

CONCLUSIONS

FC has shown a good ability to predict significant inflammatory activity in SBCE in patients with suspected CD. Thus, FC proved to be a useful tool to select patients with suspected CD for SBCE.

Unsuspected Small-Bowel Crohn's Disease in Elderly Patients Diagnosed by Video Capsule Endoscopy

Background

Video capsule endoscopy (VCE) is increasingly performed among the elderly for obscure bleeding. Our aim was to report on the utility of VCE to uncover unsuspected Crohn's disease (CD) in elderly patients.

Methods

Retrospective review of VCE performed in elderly patients (≥70 y) at a tertiary hospital (2010-2015). All underwent prior negative bidirectional endoscopies. CD diagnosis was based on consistent endoscopic findings, exclusion of other causes, and a Lewis endoscopic score (LS) > 790 (moderate-to-severe inflammation). Those with lower LS (350-790) required histological confirmation. Known IBD cases were excluded.

Results

197 VCE were performed (mean age 78; range 70-93). Main indications were iron deficiency anemia (IDA), occult GI bleeding (OGIB), chronic abdominal pain, or diarrhea. Eight (4.1%) were diagnosed as CD based on the aforementioned criteria. Fecal calprotectin (FCP) was elevated in 7/8 (mean 580 μg/g). Mean LS was 1824. Small-bowel CD detected by VCE led to a change in management in 4/8. One patient had capsule retention secondary to NSAID induced stricture, requiring surgical retrieval.

Conclusions

VCE can be safely performed in the elderly. A proportion of cases may have unsuspected small-bowel CD despite negative endoscopies. FCP was the best screening test. Diagnosis frequently changed management.

Monitoring and detection of disease recurrence after resection for Crohn's disease: the role of non-invasive fecal biomarkers

Ileocolonoscopy is the gold standard for the diagnosis and assessment of postoperative recurrence in Crohn's disease (CD). Nevertheless, endoscopy is time-consuming and invasive. A minimally invasive and simple screening test would improve patient adherence to examination and provide greater clinical benefit. A number of fecal biomarkers have been evaluated for their utility for the diagnosis and monitoring of inflammatory bowel disease as alternative tests to endoscopy. Area covered: In this review, we focused on the utility of fecal biomarkers in the management of postoperative CD. Our major endeavor was to present an evidence-based assessment of the results of clinical trials on the available data. A literature search was conducted using the Medline. Expert commentary: Calprotectin and lactoferrin, both neutrophil-derived proteins, are the two most frequently used fecal biomarkers in clinical trials and practice. Several studies evaluated the role of these fecal biomarkers in patients with postoperative CD. These studies suggest that fecal calprotectin, and to a lesser degree lactoferrin, are useful in assessing endoscopic severity and in predicting future clinical recurrence after resection for CD. However, large scale, well-designed studies are necessary to rigorously evaluate the role of fecal biomarkers in postoperative CD.

Faecal biomarkers for screening small bowel inflammation in patients with Crohn's disease: a prospective study

BACKGROUND

The value of faecal biomarkers for screening small bowel inflammation in patients with Crohn's disease (CD) remains to be elucidated. This prospective study was to evaluate the utility of faecal biomarkers for detecting small intestinal inflammation.

METHODS

A total of 122 consecutive patients with a diagnosis of CD in the small intestine were screened for eligibility. Computed tomography enterography (CTE) was undertaken to evaluate small bowel inflammation followed by colonoscopy to confirm no large bowel involvement. Seventy eligible patients with inflammation confined to the small intestine were included. Faecal samples were collected for assaying calprotectin, lactoferrin and haemoglobin. For assessing the degree of small bowel inflammation, a semi-quantitative scoring system (CTE0, normal; CTE1, mild; CTE2, moderate; CTE3, severe) was applied.

RESULTS

The median calprotectin, lactoferrin and haemoglobin levels were significantly higher in patients with small bowel inflammation, CTE scores 1-3 (n = 42) versus 0 (n = 28): calprotectin, 330 versus 40 ng/ml, p < 0.0001; lactoferrin, 14 versus 3 ng/ml, p < 0.0001; haemoglobin, 29.5 versus 6.5 ng/ml, p = 0.005. There was a strong positive relationship between the faecal biomarkers and CTE score: calprotectin, p < 0.0001; lactoferrin, p < 0.0001; haemoglobin, p = 0.0004. A cutoff value of 140 ng/ml for calprotectin had a sensitivity of 69% and a specificity of 82% with an area under the receiver operating characteristic curve (AUC) of 0.82 to detect small bowel inflammation (CTE scores 1-3), while lactoferrin 6 ng/ml had a sensitivity of 69% and a specificity of 79% with an AUC of 0.83, and haemoglobin 9 ng/ml showed a sensitivity of 71% and a specificity of 39% with an AUC of 0.70.

CONCLUSIONS

Faecal calprotectin, lactoferrin, and to a lesser degree haemoglobin are relevant biomarkers for screening small bowel inflammation in CD patients without large bowel involvement. Further well-designed large-scale studies in this clinical setting should strengthen our findings.