Diagnostic Accuracy Of Fecal Calprotectin Research Articles

Non-invasive tools for inflammatory bowel disease: A systematic review and meta-analysis of biochemical markers and intestinal ultrasound compared to endoscopy

Despite endoscopy's gold standard status, non-invasive tools are revolutionizing Inflammatory Bowel Disease (IBD) management. This systematic review and meta-analysis compared the diagnostic accuracy of biochemical markers, intestinal ultrasound (US), and endoscopy in adults with IBD. This systematic review and meta-analysis aimed to compare the diagnostic accuracy of fecal calprotectin, C-Reactive Protein (CRP), Erythrocyte Sedimentation Rate (ESR), and bowel wall thickness measured by US with endoscopy in IBD patients. We searched electronic databases for most recent studies published between 2012 and 2023, identifying 25 studies comparing at least one non-invasive tool with endoscopy. We pooled sensitivity and specificity for relevant outcomes and conducted subgroup analyses to explore heterogeneity. 25 studies (n=5872 patients) met inclusion criteria. Fecal calprotectin emerged as a powerful diagnostic tool, with pooled sensitivity of 92.5% and specificity of 85.1% for IBD. But it’s performance was less consistent in differentiating active vs. inactive disease and predicting flares. Intestinal US proved reliable for diagnosis, particularly in Crohn's disease (pooled sensitivity 86.3%, specificity 78.9%), and showed promise in assessing activity and predicting treatment response. C-Reactive Protein and Erythrocyte Sedimentation Rate, though less accurate, provided additional information about disease status. Combining calprotectin and US further enhanced prediction accuracy, while decision tree analysis incorporating clinical data and both tools maximized prediction in ulcerative colitis. Non-invasive tools offer invaluable insights for IBD management, complementing and potentially reducing reliance on endoscopy. Standardizing methodologies and developing more specific markers, potentially aided by AI, holds immense potential for personalized, effective IBD care. This evolving landscape paves the way for a future where patients actively participate in their journey, empowered by the growing arsenal of non-invasive tools.

Diagnostic Accuracy of Fecal Calprotectin in Discriminating Organic-Inflammatory Gastrointestinal Diseases and Functional Gastrointestinal Disorders in Older Patients.

Fecal calprotectin (FC) has been largely recognized as a surrogate marker of intestinal neutrophilic inflammation, very reliable in distinguishing between inflammatory bowel diseases and functional gastrointestinal (GI) disorders. Aging has been suggested to influence FC results and their diagnostic accuracy; however, no studies are specifically targeted on this focus. In a retrospective study, we evaluated the eventual age-differences of the diagnostic accuracy of FC in discriminating between organic-inflammatory GI diseases and functional GI disorders. In 573 younger and 172 older (≥65 years) subjects undergoing an FC assay, we found that the latter showed higher median FC values, 72 (25-260) µg/g vs. 47 (25-165) µg/g (p < 0.01). Younger patients were more commonly affected by IBDs, while colorectal cancer and high-risk polyps, infective colitis, and diverticular disease represented the most common findings in the older subgroup. However, the estimated optimum FC threshold in discriminating between organic-inflammatory GI diseases and functional GI disorders was quite similar between the two groups (109 μg/g for the younger subgroup and 98 μg/g for the older subgroup), maintaining a very high specificity. In conclusion, we show that FC also represents a very specific test for intestinal inflammation in older patients, at similar threshold levels to younger subjects.

P275 Fecal calprotectin, intestinal ultrasound, and their combination for the diagnosis of Crohn’s disease

Abstract Background The diagnosis of inflammatory bowel disease (IBD) is often challenging in clinical practice and performed by ileocolonoscopy, an invasive and costly procedure. We aimed to evaluate the diagnostic accuracy of fecal calprotectin (FC) and intestinal ultrasound (IUS),independently and in combination, as screening tools for adults with suspected IBD to reduce the number of unnecessary endoscopic procedures. Methods We conducted a retrospective monocentric study that included consecutive adult patients with (i) ileocolonoscopy for suspected IBD between January 2021 and June 2023 who had either (ii) IUS and/or (iii) a FC test within three months. Bowel wall thickness (BWT) (normal value ≤ 3mm) and the color Doppler signal (CDS) was evaluated for all segments. The presence of lymphadenopathy, loss of stratification, stricture, and fistula was also recorded. Results In total, 119 patients (69% females) with a median age of 32 years (IQR, 24.0-41.0) were included. The most common symptoms were abdominal pain (n=88, 75%) and chronic diarrhea (n=89, 75%). Among the 119 patients, 74 (62%) had IUS, 101 (82%) had a FC test, and 56 (47%) had both. Forty patients (34%) had a diagnosis of IBD, including 31 (26%) withCD and 9 (8%) with UC. By ROC curve analysis, the best threshold of FC to diagnose IBD was117 ug/g (Se 97%, Sp 73%, PPV 67%, NPV 98%, AUC 0.88, 95%CI [0.81; 0.94], p=0.006).Using this threshold, only 3% of patients were misclassified as non-IBD. Screening by measuring FC levels would result in a 48% reduction in the number of adults requiring endoscopy. Abnormal IUS was significantly associated with a diagnosis of IBD (OR 5.6, 95%IC[2.1; 16.2], P=0.0008). The association of a BWT &amp;gt; 3 mm and a positive CDS was associated with a Se, Sp, PPV, and NPV of 48%, 100%, 100%, and 75%, respectively, but 52% of patients were misclassified as non-IBD. The combination of a BWT &amp;gt; 3 mm, CDS, and FC &amp;gt; 117 ug/ghad a Se, Sp, PPV, and NPV of 44%, 100%, 100%, and 69%, respectively. For patients with anormal IUS and FC &amp;lt; 117 ug/g, 4% were misclassified as non-IBD. Conclusion The combination of FC and IUS is a useful screening strategy to identify patients who truly require endoscopy for suspected IBD. Calprotectin is a highly effective test for ruling out IBD. Conversely, relying solely on IUS lacks the discriminative power to safely rule out IBD.However, it shows a high PPV and is a potent tool for diagnosing IBD.

Diagnostic value of fecal calprotectin in primary care patients with gastrointestinal symptoms: A retrospective Swedish cohort study.

To investigate the diagnostic accuracy of fecal calprotectin (FC) for inflammatory bowel disease (IBD) and organic gastrointestinal disease (OGID) in primary care. To examine the association with demographic factors, symptoms and concomitant medical therapy. A retrospective analysis of data on all semiquantitative FC tests from individuals ≥18 years conducted in primary care in Östergötland County in 2010. A 5-year follow-up with inclusion of new gastrointestinal diagnoses. A total of 1293 eligible patients were included. IBD was found in 8.8% and other OGID in 30.8% of patients with positive FC. Positive FC was associated with diarrhea, age >60 years, duration <3 months, use of nonsteroidal anti-inflammatory drug (NSAID), and proton pump inhibitor (PPI). Predictors of IBD were positive FC, diarrhea, rectal bleeding, and male sex; predictors of OGID positive FC, age >35 years, abnormal clinical findings, and duration <3 months. FC yielded the highest sensitivity and negative predictive value compared with demographic factors, symptoms, and duration. Use of NSAID and PPI showed a marginal increase in the sensitivity, positive predictive value, and decrease in the specificity of FC. Within 5 years, 4.0% had a new gastrointestinal diagnosis among patients with positive FC (0.6% IBD). FC reliably rules out IBD and contradicts the presence of other OGID in primary care patients. Positive FC test together with other predictors, such as diarrhea, rectal bleeding, short duration, or age >35 years, should encourage a prioritized investigation. Use of NSAID, PPI, and ASA may affect the diagnostic accuracy of FC for IBD and OGID.

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

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

Diagnostic accuracy of fecal calprotectin in predicting significant gastrointestinal diseases.

Background and AimIt is often unreliable to triage patients for timely endoscopic investigations based on symptoms alone. We need an objective assessment to differentiate between organic gastrointestinal diseases and functional bowel symptoms. We evaluated the diagnostic accuracy of fecal calprotectin (FC) in predicting organic gastrointestinal diseases.MethodsIn a prospective observational study, consecutive patients referred for colonoscopy to the Department of Medicine and Geriatrics at the Kwong Wah Hospital in Hong Kong were recruited. Stool samples were collected within 24 h before colonoscopy. FC was measured by a commercial kit. Upper endoscopy investigations were then proceeded if normal colonoscopy but elevated FC.ResultsTwo hundred and seventy out of 429 patients had FC above 50 μg/g. Eighty‐six out of 270 with elevated FC had significant colonoscopy pathological findings. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of FC test for diagnosing a significant organic colonoscopy or upper endoscopy disease were 91.7, 55.6, 57.0, and 91.2%, respectively. The NPV of FC for colorectal cancer, high risk polyp, and colon inflammation were 98.7, 96.2, and 98.1%, respectively. The NPV of FC in the condition of altered bowel habit or abdominal pain in predicting colorectal cancer and inflammation were 93.8 and 100%, respectively.ConclusionsFC is a reliable marker of ruling out organic bowel diseases. A single negative FC test could be used as a triage tool to prioritize the need and urgency of further investigation, particularly in the setting of altered bowel habits and abdominal pain.

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/AimsThe 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.MethodsWe 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.ResultsFourteen 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.ConclusionsFC 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. (Gut Liver 2021;15-741)

Diagnostic accuracy of faecal calprotectin in a symptom-based algorithm for early diagnosis of inflammatory bowel disease adjusting for differential verification bias using a Bayesian approach

Background Diagnostic delay in IBD is a major problem and diagnosis is frequently arrived when irreversible damage has already occurred. This study evaluated accuracy of faecal calprotectin (fCAL) integrated with diagnostic criteria for early diagnosis of IBD in a primary care setting. Methods General practitioners (GPs) were trained to recognize alarm symptoms for IBD classified as major and minor criteria. Fulfilment of one major or at least two minor criteria was followed by free fCAL testing and a visit by an IBD specialist and follow-up over 12 months. All patients with positive fCAL testing, i.e., ≥70 μg/g underwent colonoscopy. The diagnostic accuracy of fCAL was estimated after adjusting for differential-verification bias following a Bayesian approach. Results Thirty-four GPs participated in the study and 133 patients were tested for fCAL between July 2016 and August 2017. Positivity of fCAL was seen in 45/133 patients (34%) and a final IBD diagnosis was made in 10/45 (22%). According to the threshold of 70 μg/g, fCAL achieved a sensitivity of 74.8% (95%CI: 39.10–96.01%), a specificity of 70.4% (95%CI: 61.76–78.16%) and an overall diagnostic accuracy of 70.6% (95%CI: 61.04–78.37%). As for prognostic accuracy, despite positive predictive value being low, 21.9% (95%CI: 11.74–35.18%), the negative predictive value was definitely higher: 96.2% (95%CI: 84.96–99.51%). Conclusions fCAL with a threshold set at 70 μg/g seems to represent a potentially reliable negative test to be used in primary care settings for patients with symptoms suggestive of IBD.

Faecal calprotectin and ultrasonography as non-invasive screening tools for detecting colorectal polyps in children with sporadic rectal bleeding: a prospective study

BackgroundColorectal polyps are reported in 6,1% of paediatric colonoscopies and in 12% of those performed for lower gastrointestinal bleeding. Although colonoscopy is widely used in paediatric patients, it requires bowel preparation and general anaesthesia or deep sedation, and in rare cases, it can cause complications. Non-invasive screening techniques able to predict polyps in children with isolated and sporadic rectal bleeding may play a key role in the selection of patients needing colonoscopy.MethodsWe enrolled all children undergoing colonoscopy for isolated and sporadic rectal bleeding to determine the diagnostic accuracy of faecal calprotectin, ultrasonography (US) and digital rectal examination as diagnostic methods for screening colorectal polyps.ResultsA total of 26 of 59 enrolled patients (44.1%) had colonic polyps, one patient had multiple polyps, and 23% of children had polyps proximal to the splenic flexure. The diagnostic accuracy of faecal calprotectin for detecting colorectal polyps was 96.6%, with a sensitivity of 100%. False-positive faecal calprotectin was shown in 2 patients with non-steroidal anti-inflammatory drug-related lesions. The diagnostic accuracy of ultrasound was 77.9%. Polyps not seen with ultrasound tended to be relatively smaller (1.5 vs 2.3, p = 0.001) and located in the rectum. The combined use of FC, US and digital rectal examination obtained a specificity and PPV of 100%.ConclusionsFC combined with US and digital rectal examination is a good and promising non-invasive screening test for detecting colorectal polyps in children with isolated and sporadic rectal bleeding.

Diagnostic accuracy of faecal calprotectin in patients with active perianal fistulas.

BackgroundFaecal calprotectin (FC) is a marker of mucosal inflammation.ObjectiveThe aim of this study was to determine the diagnostic accuracy of FC to (a) differentiate between perianal fistulizing Crohn's disease (pCD) and cryptoglandular perianal fistulas; and (b) detect mucosal inflammation in pCD.MethodsPatients with active perianal fistulas who had FC measured and a complete ileocolonoscopy within 10 weeks were retrospectively included.ResultsFifty-six patients were included (pCD, n = 37) of whom 19 pCD patients exhibited ulcers. FC was significantly higher in pCD compared to cryptoglandular fistulas (µg/g) (708.0 (207.0–1705.0) vs 32.0 (23.0–77.0), p < 0.001). Area-under-the-curve (AUC) value for FC receiver operating characteristic (ROC) statistics was 0.900. Optimal FC cut-off was ≥ 150 µg/g. To differentiate pCD from cryptoglandular fistulas in the absence of luminal inflammation, optimal cut-off remained ≥ 150 µg/g (AUC = 0.857, sensitivity = 0.81, specificity = 0.89, positive predictive value (PPV) = 93.8% and negative predictive value (NPV) = 70.8%). In pCD, FC was significantly increased in the presence of ulcers (1672.0 vs 238.0, p = 0.004). Optimal cut-off was ≥ 250 µg/g (AUC = 0.776; sensitivity = 0.89, specificity = 0.56, PPV - 68.0% and NPV = 83.0%).ConclusionFC discriminates pCD from cryptoglandular fistulas, even in the absence of intestinal ulcers. In active pCD, an elevated FC does not accurately predict the presence of ulcers and should be interpreted with caution.

Does fecal calprotectin equally and accurately measure disease activity in small bowel and large bowel Crohn's disease?: a systematic review.

Fecal calprotectin (FC) is a highly sensitive disease activity biomarker in inflammatory bowel disease. However, there are conflicting reports on whether the diagnostic accuracy in Crohn’s disease is influenced by disease location. The aim of this study was to undertake a systematic review of the published literature. Relevant databases were searched from inception to November 8, 2016 for cohort and case control studies which had data on FC in patients with isolated small bowel (SB) and large bowel (LB) Crohn’s disease. Reference standards for disease activity were endoscopy, magnetic resonance imaging, computed tomography or a combination of these. The QUADAS-2 research tool was used to assess the risk of bias. There were 5,619 records identified at initial search. The 2,098 duplicates were removed and 3,521 records screened. Sixty-one full text articles were assessed for eligibility and 16 studies were included in the final review with sensitivities and specificities per disease location available from 8 studies. Sensitivities of FC at SB and LB locations ranged from 42.9% to 100% and 66.7% to 100% respectively while corresponding specificities were 50% to 100% and 28.6% to 100% respectively. The sensitivities and specificities of FC to accurately measure disease activity in Crohn’s disease at different disease locations are diverse and no firm conclusion can be made. Better studies need to be undertaken to categorically answer the effect of disease location on the diagnostic accuracy of FC.

P029 ACCURACY OF FECAL CALPROTECTIN IN DETECTING SMALL BOWEL CROHN’S DISEASE: A META-ANALYSIS AND SYSTEMATIC REVIEW

Identifying active small bowel Crohn’s Disease (CD) is often challenging due various reasons. The location of Crohn’s disease and often the disease process itself make direct visualization difficult. Fecal calprotectin (FCP) is a well-established marker of mucosal inflammation. Several studies have confirmed FCP’s utility in colonic inflammation; however, the diagnostic accuracy in active small bowel inflammation had yet to be established. The aim of the present study is to update the previous meta-analysis of FCP and its diagnostic accuracy in detecting active small bowel Crohn’s disease. A comprehensive search was performed using PubMed/OVID studies. Studies from 2010 until 2018 addressing patients with suspected or known CD and evaluated with noninvasive testing with FCP and confirming disease with video capsule endoscopy or imaging were included. Studies in which a 2 X 2 table with true positives, false negatives, false positives and true negative values could be constructed were included. Meta-analysis for the diagnostic accuracy of fecal calprotectin in diagnosing active small bowel CD was performed by calculating pooled estimates of sensitivity, specificity, likelihood rations, and diagnostic odds ratios. Pooling was conducted by both fixed and random effects models. Data was extracted from 17 studies which met the inclusion criteria. In CD patients, pooled sensitivity of fecal calprotectin was 76.50% (95% CI: 73.00 – 79.00) in diagnosing small bowel Crohn’s disease. Fecal calprotectin had a pooled specificity of 71.10% (95% CI: 68.00 – 73.00) for detecting active small bowel Crohn’s disease. The diagnostic odds ratio, of having active small bowel disease with elevated FCP was 12.28 (95% CI: 6.55 – 23.01). The positive likelihood ratio of FCP was 3.093 (95% CI: 2.16 – 4.41), and the negative likelihood ratio was 0.30 (95% CI: 0.21 – 0.43). Fecal calprotectin has moderate diagnostic accuracy for detecting active small bowel CD. Our results suggest a fecal calprotectin of at least 50 µg/g has moderate sensitivity and specificity. These values are proportional to the fecal calprotectin level.

Diagnostic accuracy of fecal calprotectin for screening patients with colorectal cancer: A meta-analysis.

Fecal calprotectin (FC) is reported to have a broad diagnostic accuracy for colorectal cancer (CRC). Therefore, we explored the diagnostic value of FC for CRC using meta-analytical techniques to substantiate the assertion. An electronic search of the MEDLINE and Embase databases was conducted to identify studies that assessed the diagnostic accuracy of FC for CRC. The sensitivities and specificities of the eligible studies were summarized using a bivariable random-effects model. In total, 20 studies were included in the final analysis. The pooled sensitivity, specificity, positive likelihood ratio, and negative likelihood ratio of FC for CRC detection were 0.83 (95% confidence interval CI, 0.77-0.88), 0.61 (95% CI, 0.54-0.68), 2.15 (95% CI, 1.82-2.55), and 0.28 (95% CI, 0.21-0.37), respectively. The overall diagnostic odds ratio of FC for CRC was 7.76 (95% CI, 5.41-11.12) with an area under the curve of 0.81 (95% CI, 0.77-0.84), whereas the diagnostic value of FC for colorectal adenoma was relatively inferior (area under the curve, 0.55; 95% CI, 0.51-0.59; diagnostic odds ratio, 1.27; 95% CI, 0.91-1.78). The results imply that the FC test, as currently implemented, cannot be recommended for CRC detection.

P150 Low diagnostic accuracy of faecal calprotectin to predict mucosal inflammation in Crohn’s disease patients with active perianal fistulas

P150 Low diagnostic accuracy of faecal calprotectin to predict mucosal inflammation in Crohn’s disease patients with active perianal fistulas

P128 Diagnostic accuracy of faecal calprotectin in Crohn's disease – Does disease location matter?

Background: Faecal calprotectin (FC) is a highly sensitive disease activity biomarker in Inflammatory Bowel Disease. However there are conflicting reports on whether the diagnostic accuracy in Crohn's disease (CD) is influenced by disease location. The aim of this study is to undertake a systematic review of published literature to compare the sensitivity and specificity of FC to accurately measure disease activity at small bowel (SB) vs large bowel (LB) location. Methods: Databases (Medline, Embase, Web of Science and Cochrane) were searched from inception to November 8th 2016 for cohort and case control studies which had data on FC in patients with isolated SB and LB CD. Similarly, relevant conference proceedings were searched from 2005–2016. There was neither age nor language restriction. The reference standard for activity was either endoscopy, magnetic resonance imaging, computed tomography, technetium scan or a combination of these. We excluded studies reporting on post-operative CD or on a specific disease location in isolation. Screening was done independently in duplicate (EGS, RW), with any disagreements resolved by 2 other authors (GWM, SS). EGS & GWM independently completed data extraction form. To assess the risk of bias; EGS & GWM used QUADAS-2, a research tool to check the quality of systematic reviews of diagnostic accuracy studies. Any disagreement was resolved by consensus with co-authors. Communication was undertaken with all lead authors in order to obtain missing data sets. Whenever possible, sensitivities and specificities were obtained from the raw data or as reported in the publication. Results: 5619 records were identified at initial search. 2098 duplicates were removed and 3521 records were screened. From the latter, 61 full text articles were then assessed for eligibility. 45 studies were later excluded and 16 studies were included in the final review, with sensitivities and specificities per disease location available from seven studies. The sensitivity of FC in the SB location ranged from 42.9% to 100% with a median of 75%, while that in the LB location ranged from 78.9% to 100% with a median of 94%. FC specificity in the SB location ranged from 50% to 100% while that in the LB location ranged from 28.6% to 100% with similar median specificities of 75% and 71% respectively. Conclusions: The sensitivity of FC to accurately measure disease activity for CD in the SB appears to be lower than that in the LB. Limitations of the study include heterogeneity associated with the cut offs of FC, disease spectrum, study design, gold standard used and quality of studies as well as insufficient raw data.

P214 What is the diagnostic accuracy of faecal calprotectin regarding endoscopic relapse in Crohn's disease patients following ileocecal resection? A tertiary single center experience

Background: There is still some discrepancy about the accuracy of faecal calprotectin (FC) in Crohn's disease (CD) patients after ileocecal resection and data from real daily practise on this topic is still scarce. Methods: For this purpose we prospectively gathered the simultaneous FC results of CD patients who were referred to the endoscopy unit in the postoperative (postop) setting. Patients with upper GI involvement were excluded. Demographic data like age, sex, disease duration, Rutgeerts score, FC, CRP results were all noted. All patients gave a stool sample 24 hours before colonoscopy and FC was determined via ELISA (Quantum Blue Calprotectin, Bühlmann Lab. AG, Switzerland). Results: Seventy-four CD patients [38 female (51%)] with an ileoceal resection were enrolled into the study protocol. Their mean age was 38.56±12 yr. with a mean disease duration of 123.52±84.88 mo. Fourty-four of 74 (60%) patients were in endoscopic remission whereas 30 (40%) had endoscopic relapse [i0- 31 patients (42%); i1- 13 patients (18%), i2- 11 patients (15%), i3- 14 patients (19%), i4- 5 patients (6%)]. Nonparametric Spearman correlation test only revealed that FC using a cut off of 30 μg/g weakly correlated with endoscopic relapse (r=0.329, p=0.004). Diagnostic accuracies of FC using different cut offs is shown in Table 1. Table 1 Diagnostic performance of FC regarding endoscopic relapse using different cut offs Conclusions: According to our results from our daily routine practise, the very low specificity of FC for each cut off in CD patients with an ileocecal resection lets us question the diagnostic utility of this non-invasive marker as an alternative tool to colonoscopy in the postop setting. A speculative explanation for this could either be the presence of unidentified lesions proximal to the ileocolonic anastomosis or ischemic anastomotic ulcers which might have been the reason behind the confusion of the endoscopist and let us judge the value of Rutgeerts score.

Diagnostic accuracy of fecal calprotectin in assessing the severity of inflammatory bowel disease: From laboratory to clinic.

Background:Inflammatory bowel disease (IBD) involves chronic inflammation of the digestive tract. In the past decades, fecal calprotectin has been proposed as a useful biomarker for the differential diagnosis between IBD patients and healthy controls. We designed this study to evaluate the diagnostic ability of fecal calprotectin (FC) and conventional inflammatory markers in IBD patients.Methods:Thirty patients who underwent colonoscopy were cases and thirty healthy subjects undergoing colonoscopy as part of a medical check-up were the controls. These 2 groups were evaluated with regard to age and sex. Severity of the disease was evaluated based on disease endoscopic index. FC, Cross reactive protein (CRP) and Erythrocyte sedimentation rate (ESR) were measured using ELISA, colorimetric and Westergren methods, respectively. The obtained data were analyzed by independent test, correlation test and receiver operating characteristic (ROC) curve analysis. A p<0.05 was considered statistically significant.Results:Fecal calprotectin level in the case group increased compared to control group (p<0.05). Moreover FC has stronger correlation with disease endoscopic activity than conventional inflammatory markers (r=0.847 versus r= -0.44 for CRP and r=0.054 for ESR in Crohn's disease and r=0.798 versus r=0.463 for CRP and r=0.467 for ESR in ulcerative colitis). Receiver operating characteristic (ROC) curve analysis showed FC has larger area under the curve (AUC) than conventional inflammatory markers (1 versus 0.849 for CRP and 0.846 for ESR).Conclusion:Discriminating IBD patients from healthy controls was better for FC than conventional inflammatory markers. Additionally, the results produced by FC correlate with the severity of IBD.

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

Faecal calprotectin (FC) is less accurate at identifying inflammation in the small bowel than in the colon. Small bowel capsule endoscopy (SBCE) is a useful tool to detect small bowel inflammation. We investigated the diagnostic accuracy of FC and SBCE and their correlation in patients with suspected isolated small bowel Crohn's disease. This was performed as a prospective single centre study including patients attending for SBCE with suspected small bowel Crohn's disease. Patient demographics, symptoms, medications and blood parameters were collected. Capsule endoscopy findings were analysed against calprotectin values, final diagnosis and blood parameters. A total of 146 patients were included (99 females and 47 males) with a mean age of 38±14 years. FC of more than 50 mg/kg was not significantly associated with clinically relevant capsule endoscopy findings (P=0.25), correlation coefficient was 0.11. Sensitivity, specificity, positive and negative predictive values for FC at a cut-off of more than 50 mg/kg were 88.9% [95% confidence interval (CI): 65.3-98.6], 25.0% (95% CI: 17.8-33.4), 14.3 (95% CI: 8.4-22.2) and 94.1% (95% CI: 80.3-99.3), respectively. A raised FC was not significantly associated with an elevated C-reactive protein or the presence of anaemia (P=0.19 and 0.10, respectively). FC performs modestly as a screening test to exclude small bowel inflammation. However, we recommend interpretation within the overall clinical context to avoid overlooking the infrequent patient with small bowel inflammation and a negative FC.

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

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. 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. 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). 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.

PTU-012 Faecal Calprotectin as Predictor of Small-Bowel Crohn’s Disease in Capsule Endoscopy – A Systematic Review and Meta-Analysis

Introduction Faecal calprotectin (FC) is a well-established marker of gut inflammation. While the correlation of elevated FC levels with colonic inflammation has been confirmed in several studies,1,2 data regarding the correlation of FC with small-bowel inflammation is either scarce or conflicting.3 Capsule endoscopy (CE) is the modality of choice for detection of small-bowel inflammation and/or small-bowel Crohn’s disease (CD).4 Therefore, we aimed to systematically review and meta-analyse the evidence for the diagnostic accuracy of FC as a predictor of small-bowel CD. Methods A comprehensive literature search of the databases PubMed and Embase was performed, using the search string: “capsule endoscopy” + calprotectin. Studies including patients with suspected and/or established CD evaluated by both FC and CE were retrieved. Corresponding authors were contacted for any missing data. The following FC cut-offs were evaluated: >50, 100 and 200 μg/g, as available in each included study. A diagnostic meta-analysis was performed; pooled diagnostic sensitivity (Se), specificity (Sp) and diagnostic odds ratio (DOR) with 95% confidence intervals (95% CI) were obtained for each of the cut-offs. Bias was evaluated using the quality assessment of studies of diagnostic accuracy in systematic reviews (QUADAS) 2 tool. A minimum of 4 studies was required for each analysis. Results A total of 135 studies were identified; seven (3 prospective, 4 retrospective) studies, including 463 patients, entered the final analysis. Overall, the methodological quality of the studies was high, with 6/7 studies showing low risk of bias. For studies including only patients with suspected CD, the diagnostic accuracy of FC for the cut-off of 50 μg/g was as follows: 5 studies, 305 patients; Se 89% (CI 68%;97%), Sp 55% (CI 36%;73%), DOR 10.3 (CI 3.7;28.6) . For all included studies (suspected and established CD), the DOR was significant for all the evaluated FC cut-offs. FC > 50μg/g: 7 studies, 463 patients; Se 83% (CI 73%;90%), Sp 53% (CI 36%;71%), DOR 5.64 (CI 3.2;10.1). FC > 100μg/g: 5 studies, 379 patients; Se 68% (CI 56%;76%), Sp 71% (CI 46%;88%), DOR 5.01 (CI 2.03;12.07). FC > 200μg/g: 4 studies, 309 patients; Se 42% (CI 26%;64%), Sp 94% (CI 64%;99%), DOR 13.64 (CI 2.01;88.6). Sensitivity analysis based on methodological quality did not change those results significantly. Conclusion This meta-analysis confirms that FC, when used as a predictor of small-bowel CD prior to CE, has high diagnostic accuracy. For patients with suspected CD, a FC cut-off level of 50 μg/g provided high sensitivity and DOR, while for the entire patient cohort (suspected and established CD) FC > 200 μg/g provided the best overall DOR. The likelihood of diagnosing small-bowel CD is extremely low in suspected CD patients with FC References 1 D’Haens G, et al. Faecal calprotectin is a surrogate marker for endoscopic lesions in inflammatory bowel disease. Inflamm Bowel Dis 2012;18:2218–2224. 2 Van Rheenen PF, et al. Faecal calprotectin for screening of patients with suspected inflammatory bowel disease: diagnostic meta-analysis. BMJ 2010;341:c3369. 3 Mao R, et al. Faecal calprotectin in predicting relapse of inflammatory bowel diseases: A meta‐analysis of prospective studies. Inflamm Bowel Dis 2012;18:1894–1899. 4 Annese V, et al. European evidence based consensus for endoscopy in inflammatory bowel disease. J Crohns Colitis 2013;7:982–1018. Disclosure of Interest None Declared