Fecal Calprotectin Assay Research Articles

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.

Diagnostic Performance of a Fecal Calprotectin Assay as a Biomarker for Mayo Endoscopic Subscore in Ulcerative Colitis: Result From a Tertiary Referral Center.

Fecal calprotectin (FC) is a promising biomarker for assessing ulcerative colitis (UC) endoscopic activity. However, the optimal FC cutoff to identify each Mayo endoscopic subscore (MES) remains inconclusive. The electronic medical records of 177 adult UC patients evaluated at Mayo Clinic Rochester from January 2017 to March 2023 were retrospectively reviewed, obtaining clinical data and US-based Werfen Diagnostics FC levels collected within 30 days before colonoscopy or flexible sigmoidoscopy. Three independent inflammatory bowel disease specialist endoscopists blindly reviewed the most severe endoscopic images for grading MES. The median interval between FC collection and endoscopy was 2 days. Fecal calprotectin showed strong positive correlations with MES (Spearman's r = 0.709; P < .01) and other clinical parameters. Fecal calprotectin cutoff of 60 mcg/g effectively distinguished MES 0 from MES 1-3 (sensitivity, 0.78; specificity, 0.97; area under the receiver operating characteristic curve [AUC], 0.901) and predicted clinical remission (Total Mayo Score ≤2 and no subscore >1; sensitivity, 0.83; specificity, 0.98; AUC, 0.921). Fecal calprotectin cutoff of 110 mcg/g effectively differentiated MES 0-1 from MES 2-3 (sensitivity, 0.86; specificity, 0.87; AUC, 0.915), while a cutoff of 310 mcg/g distinguished MES 0-2 from MES 3 (sensitivity, 0.80; specificity, 0.76; AUC, 0.820). This study supports the reliability and applicability of FC as a valuable marker of endoscopic inflammation, particularly in distinguishing MES 0 from MES 1-3 using the FC cutoff of 60 mcg/g. Sensitivity analysis demonstrated robust results.

UNAFFECTED RELATIVES WITH HIGH IBD POLYGENIC RISK SCORES FROM MULTIPLEX CROHN’S DISEASE FAMILIES CARRY MICROBIOMES THAT PROTECT IL-10 DEFICIENT MICE AGAINST INTESTINAL INFLAMMATION

Abstract Genetic and environmental influences contribute to Crohn’s disease (CD) development. However, the relationship between these two factors is unclear, limiting insights into CD pathophysiology, as well as interventions to prevent disease. To address this knowledge gap, we performed a longitudinal study of entire multiplex families to identify relatives discordant between their genetic risk for disease, as calculated by an IBD polygenic risk score (PRS), and their CD status. Fecal specimens were collected quarterly (up to 32 months) for assessment of intestinal inflammation by fecal calprotectin assays and gut microbiome composition by 16S sequencing. We evaluated 8 candidate IBD PRS, and the best performing score across all families was used to rank each subject by genetic risk. Untargeted fecal metabolomic analysis was performed on a single specimen chosen from each of the 5 subjects that best represented the following categories: CD+/high PRS, CD-/high PRS, CD+/low PRS, and CD-/low PRS. To avoid potential confounders, we excluded the following specimens: elevated calprotectin, collected &amp;lt; 3 months since antibiotic use, or from pediatric subjects, who may still develop CD. From these 20 samples, 12 fecal specimens (3 from each category) were each gavaged into 5 germ-free IL-10 deficient mice (male, SvEv129, 7.5-12 weeks old). As a control, 4 other mice were gavaged with a fecal slurry from age- and sex-matched Murine Pathogen Free 129S6/SvEvTac mice. Mice were maintained in isolator cages with sterile food, water, and bedding. A score evaluating weight loss, pellet consistency, and fecal blood was used to measure disease activity over time. We studied 396 fecal specimens from 52 subjects across four multigenerational families. We found low microbiome diversity and an altered microbial composition based on 16S sequencing of 12 CD-affected subjects compared to unaffected relatives. Among subjects with CD, we observed an inverse correlation between microbiome diversity and PRS that included CD-relevant genetic variants. There was no relationship between PRS and microbiome diversity among unaffected relatives or with a PRS using ulcerative colitis-specific genetic variants. Among relatives with high PRS, those protected from disease (i.e., CD-/high PRS) had high relative abundance of multiple fecal metabolites (Figure 1). Germ-free IL-10 deficient mice gavaged with these fecal specimens showed reduced disease activity - on par with mice treated with human inocula from those with no CD or low PRS (Figure 2). In contrast, mice colonized with CD+/high PRS inocula displayed high disease activity immediately following gavage. In conclusion, our findings suggest the presence of a CD-protective factor within the gut microbiome of unaffected relatives with high PRS that is transferable and that mitigates disease activity in an IBD mouse model. Figure 1 Fecal small molecules that characterize Crohn’s disease risk in multiplex families. 10 subjects with high genetic risk for CD, half with disease and half without, underwent untargeted metabolomic analysis by hybrid liquid chromatography-mass spectrometry. For each subject, the single optimal specimen was identified from longitudinal sampling to avoid sampling near antibiotic use or with intestinal inflammation (determined by the biomarker, fecal calprotectin). Unsupervised clustering analysis of the 460 differentially abundant metabolites (p Figure 2 Disease activity index (DAI) over time by different inocula. DAI differs based on treatment inocula (p=0.001) as determined by two-way ANOVA testing. Pairwise t-tests show that this difference is driven primarily by the DAI induced by the CD, high PRS inocula compared to other human inocula groups (p=0.002-0.009). DAI in the CD-protected group (no CD, high PRS) is on par with mice treated with No CD and Low PRS inocula.

P473 Comparison of clinical performance of fecal calprotectin of laboratory methods with lateral flow based POC and home tests

Abstract Background To confirm an IBD diagnosis and manage IBD patients, endoscopy is the gold standard to assess mucosal inflammation. Fecal calprotectin (fCAL) is a reliable biomarker of intestinal inflammation that highly correlates with endoscopic and histological findings. Fecal calprotectin testing is recommended in most IBD guidelines for diagnosis and disease course evaluation. Different assay technologies exist that need to measure fecal calprotectin comparably. These range from classic enzyme linked immunosorbent assays (ELISA), particle enhance turbidimetric immuno assays (PETIA), and rapid lateral flow assays (LFIA). LFIA[AL1] [RC2] s can be read by conventional tabletop readers or by everyday smartphone applications using the phone’s camera to acquire an image, detect the test cassette and calculate a quantitative result. As there is no international standard to date, fecal calprotectin assay manufacturers rely on their own internal calprotectin standardization. This study compared four different assays measuring the same clinical samples. Methods The 128 raw stool samples that were analyzed in this study were obtained from patients that presented with signs and symptoms suggesting intestinal inflammation and underwent endoscopic evaluation to establish or exclude an IBD diagnosis. Samples were extracted with the BÜHLMANN CALEX® Cap stool extraction device. Each extract was then measured on the BÜHLMANN fCAL® ELISA, fCAL® turbo (PETIA), Quantum Blue® fCAL extended lateral flow assay and smartphone based IBDoc® fCAL home test. For the home test, two phones, iPhone 11 and Samsung Galaxy S7, were used to measure the lateral flow test cassettes. Each sample was measured one time on each assay and Receiver Operating Characteristic (ROC) curve analysis was performed and total agreement between each method was calculated. Results ROC curves were generated to assess the ability of each assay to differentiate between IBS and IBD with area under the curve (AUC) values ranging from 0.827 (Samsung Galaxy S7 to 0.835 (fCAL turbo). There was no significant difference between the methods. Commonly used cut-offs in the assessment of IBD patients are 100 and 250 µg/g, respectively. Positive and negative percent agreement (PPA/NPA) between the smartphone-based home test and the laboratory assays was calculated. The PPA was above 90% for all methods while the NPA was above 88% for all methods. Conclusion The results presented here show that the four BÜHLMANN assays measure fecal calprotectin extremely comparably and show an excellent clinical performance. This allows for the use of the methods interchangeably, depending on the needs of the patients and their care team.

Verification of the Bühlmann fCAL turbo faecal calprotectin assay on the Binding Site Optilite benchtop analyser

ObjectivesInflammatory bowel disease (IBD) and irritable bowel syndrome (IBS) are increasingly prevalent disorders. Faecal calprotectin is useful in the differential diagnosis of IBD from IBS and monitoring IBD activity. We verified the Bühlmann fCAL turbo faecal calprotectin assay on the Binding Site, Optilite benchtop analyser. DesignAccuracy, precision, lower limit of quantitation (LLoQ), and linearity of the Bühlmann fCAL turbo faecal calprotectin assay on the Binding Site, Optilite benchtop analyser were ascertained. Comparison with the Bühlmann Quantum Blue fCAL extended and DiaSorin, Liaison calprotectin assays were also undertaken. Difference between assays was evaluated using the Wilcoxon signed-rank test and method comparison was undertaken using Spearman’s rank correlation (rs), difference plots and Passing-Bablok regression analyses. ResultsThe fCAL turbo assay was linear between 25 and 10,000 μg/g, and the LLoQ was 25 μg/g. Intra-, and inter-assay imprecision was <5%. There was a good agreement (rs = 0.96) and no significant bias (3%, p = 0.10) present between the fCAL turbo and Quantum Blue extended assays. Between the fCAL turbo and DiaSorin, liaison assays there was a good agreement (rs = 0.97), but a significant bias (53%, p = <0.01) was present. ConclusionsThe fCAL turbo assay performs well on the Binding Site, Optilite benchtop analyser. Calprotectin results are commutable between with Bühlmann fCAL turbo and Quantum Blue fCAL extended assays, but not between Bühlmann and DiaSorin calprotectin assays.

High levels of fecal calprotectin and C-reactive protein in patients with colitis.

Inflammatory bowel disease (IBD) with a poor prognosis may be due to persistent colitis. According to the latest guidelines, monitoring has become a part of the treatment process for colitis. Adequate monitoring of the patient's condition is necessary to determine the course of the disease to prevent the worsening of the condition and suppress the subclinical inflammatory process. This analytical study with a cross-sectional design was conducted to evaluate the activity of colitis using the results of C-reactive protein (CRP) and fecal calprotectin (FC) assays. FC levels were analyzed by ELISA, while CRP levels were analyzed using Siemens Flex particle-enhanced turbidimetric immunoassay. In 30 subjects with endoscopy and biopsy of colitis, 16 men and 14 women had a median age of 52.5 (18-70) years. The median FC value increased by 67 (7.3-722 g/g) and was positive (≥50 g/g) in 20 subjects (66.7%), and the mean CRP value was 13.64 mg/L, positive (10-15 mg/L) in 13 subjects (43.33%), and negative (<10 mg/L) in 17 subjects (56.67%). This study demonstrated that FC had a significant relationship with CRP (r=0.57; p<0.001) in patients with colitis. Assessing the levels of FC and CRP among patients with colitis can be useful to assess the worsening of symptoms early and reduce mortality and morbidity.

New Faecal Calprotectin Assay by IDS: Validation and Comparison to DiaSorin Method.

Background: The faecal calprotectin (FC) measurement is used for inflammatory bowel disease (IBD) diagnosis and follow-up. The aim of this study was to validate for the first time the new IDS FC extraction device and immunoassay kit, and to compare it with the DiaSorin test in patients with and without IBD. Methods: First, the precision of the IDS assay and its stability were assessed. Then, 379 stool extracts were analysed with the IDS kit on iSYS and compared with a DiaSorin Liaison XL assay. Results: The intra- and inter-assay CVs did not exceed 5%. The stool samples were stable up to 4 weeks at −20 °C. Lot-to-lot comparison showed a good correlation (Lot1 = 1.06 × Lot2 + 0.60; p > 0.05). The Passing and Bablok regression showed no significant deviation from linearity between the two methods (IDS = 1.06 × DiaSorin − 0.6; p > 0.05; concordance correlation coefficient = 0.93). According to the recommended cut-offs, the IDS assay identified more IBD and irritable bowel syndrome patients than DiaSorin, which had more borderline results (16 vs. 20%, respectively). Conclusions: The IDS faecal calprotectin had good analytical validation parameters. Compared to the DiaSorin method, it showed comparable results, but slightly outperformed it in the identification of more IBD patients and active disease.

Associations Between Maternal Microbiome and Incidence of Low-Birth Weight in Four Low- and Middle-Income Countries

ObjectivesRecent studies suggest that maternal inflammation in pregnancy may be associated with poor obstetric and perinatal outcomes. The goal of this study was to examine relationships between maternal microbiome (taxonomic and functional abundance), maternal anthropometry and markers of inflammation on birth weight and incidence of low birth weight (<2500 g) in resource-limited settings. MethodsThis was secondary analysis from the Women First trial conducted in semi-rural regions of Guatemala, Pakistan, India and the DRC. Maternal weight was measured at 12 and 34 wk of pregnancy. Infant measures were collected within 48 h of delivery. Fecal samples at 12 and 34 wk were used for microbiome analysis (16S rRNA gene amplicon sequencing) and fecal calprotectin and myeloperoxidase assays. Sample sizes for microbiome data at 34 wk were n = 96–249 depending on the site. Linear mixed models using the MaAslin2 package were utilized to assess changes in microbiome associated with birth weight or LBW. Predictive models using gradient boosted machines (XGBoost) were developed using the H2o.ai engine. ResultsMicrobiome composition (β-diversity) was significantly different between sites and between 12 and 34 wk pregnancy within each site (p < .0.05). No differences in β-diversity were observed at either time point between mothers with LBW infants relative to non-LBW infants. Shannon diversity at 12 wk in Pakistan was lower in mothers with LBW infants. Notable differences in genus-level abundance between LBW and non-LBW mothers (p < 0.05) were observed in Klebsiella and Rothia (Pakistan); Phascolarctobacterium (India); Howardella (DRC); and Bacteroides (Guatemala). However, no overlap in differentially abundant taxa was observed between sites suggesting distinct alterations associated with birth weight. Classification models to predict LBW among all sites including maternal anthropometry, inflammation and predicted microbial functions showed moderate performance (72% accuracy, 77% sensitivity and 47% specificity on 20% test data). ConclusionsCollectively, the findings indicate population-specific alterations in the maternal microbiome associated with infant LBW. A more granular analysis of microbiome, metabolome and maternal anthropometry has the potential for more robust prediction. Funding SourcesBill & Melinda Gates Foundation, NIH/NICHD/ODS.

Comparison of fecal calprotectin and pancreatic elastase assays based on proficiency testing results

BackgroundFecal calprotectin and fecal pancreatic elastase assays are not standardized because of a lack of suitable reference material. Laboratories may have difficulty in switching assays because different manufacturers do not compare well with each other despite having similar reference intervals. Data from proficiency testing performed in Germany (Fecal Diagnostics 01 Survey, INSTAND eV) were investigated to understand how results differed across eight calprotectin and five pancreatic elastase manufacturers. MethodsData were collected from participating laboratories in external quality assessment schemes from 2015 to 2020 for calprotectin and 2017 to 2020 for pancreatic elastase. The manufacturer group mean values and standard deviations were calculated. Reference points were created for each external quality assessment scheme by calculating the average of all manufacturer group means. Deming regression analyses were used to observe the differences across manufacturers. ResultsThe slopes of the Deming regression spanned 0.37–1.91 for calprotectin and 0.84–1.33 for pancreatic elastase. The calprotectin assays had a high degree of variability in quantitative results by manufacturer. However, pancreatic elastase assays appear to be harmonized across the different manufacturer when considering the qualitative interpretation. ConclusionsBoth calprotectin and pancreatic elastase assays could be improved by standardization efforts. Given the clinical utility and our data demonstrating high inter-manufacturer variability, calprotectin should be prioritized over pancreatic elastase in standardization efforts.

Analytical and clinical evaluation of DiaSorin Liaison® Calprotectin fecal assay adapted for serum samples.

BackgroundCalprotectin is a calcium‐binding protein that can be measured in serum, plasma, and feces. Increased serum and plasma calprotectin concentrations have been found in chronic inflammatory rheumatic disorders. An analytical and clinical evaluation of the DiaSorin Liaison® fecal Calprotectin assay using LIAISON® XL was performed.MethodsThe protocol included an analytical and clinical evaluation in which imprecision, the linearity of dilution, differences between serum and plasma samples and method comparison with CalproLab™ ELISA kit were assessed. Serum calprotectin concentrations in active (n = 26) and remission (n = 23) rheumatoid arthritis (RA) patients were compared.ResultsThe intra‐day and inter‐day analytical imprecision CVs ranged from 2.9% to 4.0% and 2.7% to 10.4%, respectively. Correlation between measured and expected values was high (R > 0.99), indicating good linearity. The Wilcoxon signed‐rank test showed that serum and plasma matched samples presented statistically significant differences (p < 0.001) being the highest concentrations of calprotectin observed in serum samples. Deming regression equation was as follows: Diasorin calprotectin (μg/ml) = −0.32 (95% CI: −0.65 ‐ −0.05) +1.58 (95% CI: 1.42–1.79).* Calprolab calprotectin (μg/ml). Significantly higher serum calprotectin levels were found in RA patients with active disease when compared to patients with low disease activity or in clinical remission (mean ± SD) [(3.35 μg/ml ± 1.55) vs. (1.63 μg/ml ± 0.52), p < 0.001] and these levels correlated well with all disease activity indices.ConclusionsThe DiaSorin Liaison® fecal Calprotectin assay adapted for serum samples showed adequate technical performances and the clinical performances were similar to other assays.

Effects of oral vitamin D3 supplementation in Crohn's disease patients: Modulation of clinical active/remission phases by pro-inflammatory cytokines profile and oxidative stress

The 25-hydroxyvitamin D3 (25OHD3) deficiency in Crohn's disease (CD) is associated with the immune system dysfunction and redox status alteration. These two events affect intestinal mucosal function through macrophages cells infiltration and to lead a pro-inflammatory cytokines storm and ROS (reactive oxygen species) overproduction. The objective of this study was to investigate the immunomodulatory and antioxidant effects of vitaminD3 supplementation (DS3) in clinical active phase. A cohort of 262CD patients and vitaminD deficient (<50nmol/L or <20ng/mL) was randomized into 2groups according to the DS3 doses at 200,000IU/month (D200 group) versus 6,000IU/day (D6 group). Serum 25OHD3 levels were assessed before and after 6 and 12months of DS3. The clinical active phase was characterized by the CDAI score (Crohn's Disease Activity Index) and the fecal calprotectin assay. The 25OHD3 profile was analyzed by LC-MS/MS. The pro-inflammatory cytokines (TNFα, IL-6, IL-12, IL-17, IL-23) were assessed by ELISA tests. The serum trace elements (Se, Mn, Cu, Zn) was determined by mass spectrometry. The antioxidant status (TAS, SOD, GPx, GSH) was evaluated by Randox kits. The results showed that the serum 25OHD3 concentrations became normal (>75nmol/L or >30ng/mL) in the 2groups. Our data showed that vitaminD supplementation allowed the clinical remission phase. The DS3 decreased serum levels of CRPus, TNFα, IL-17 and IL-23. The DS3 modulates the trace elements ratio and increased the SOD and GPx activities. The DS3 corrects the denutrition state. The vitaminD supplementation benefits are more significant in D6 group (continuous 6,000IU/day) than in D200 group (intermittent 200,000IU/month). Our study suggests that the serum 25OHD3 profile can be considered a reliable biomarker in the bioclinic CD evolution to prevent the active phase, to extend the remission phase and to avoid the surgical bowel resection.

P250 Clinical validation of a point of care test for fecal calprotectin in distinguishing irritable bowel syndrome from Inflammatory Bowel Disease

Abstract Background Calprotectin is a small calcium-binding protein that when measured in human stool has shown utility in assessing the degree of bowel inflammation in inflammatory bowel disease (IBD) and in distinguishing IBD from irritable bowel syndrome (IBS). However, most fecal calprotectin (FCP) assays are slow and inconvenient. This study examined the analytical agreement and clinical utility of a point of care (POC) assay for FCP. Methods A fast (~5 min.), time-resolved fluorescence resonance energy transfer based immunoassay (Procise FCP™) was developed for the POC measurement of FCP using 15 mg of fecal specimen eluted in collection fluid from the Procise Stool Collection Device™. The analytical agreement between the Procise FCP assay and a commercial ELISA assay: Inova Quanta Lite Calprotectin Extended Range was assessed using 46 leftover deidentified fecal specimens. Clinical performance of the assay was assessed using stored frozen stool specimens from a nested cohort derived from a prospective study of chronic diarrhea patients. Chronic diarrhea was defined as unexplained diarrhea of at least 4 weeks duration. Study subjects were males and females of ages 2 – 70 with no chronic liver disease and were consecutively enrolled. Diagnoses were made by attending physicians, and IBD patients did not necessarily have active disease beyond diarrhea at the time of specimen collection. Primary endpoint: Proportion of patients diagnosed with either IBS or IBD testing positive for FCP. Statistical analysis Method comparison analysis was performed by Deming linear regression. A post hoc analysis of patients from the diarrhea study diagnosed with either IBS or IBD was performed. The significance of the proportion of patients diagnosed with either IBS or IBD testing positive for FCP was calculated using Fisher’s Exact Probability Test. The assay was assessed at cut-offs of 50 µg/g and 120 µg/g. Results Figure 1. Table 1. Table 2. Conclusion The Procise FCP assay shows excellent analytical agreement to another commercial FCP assay and can clinically significantly distinguish between IBD and IBS in chronic diarrhea patients. Thus, the assay can aid in the differentiation of IBD from IBS. Distinguishing IBS from IBD with a convenient POC format test enhances the clinical utility of FCP by enabling faster treatment response

Fecal Calprotectin Assay at an Early Stage of Treatment Can Be Used as a Surrogate Marker to Predict Clinical Remission and Mucosal Healing in Pediatric Crohn's Disease.

PurposeThis study evaluated the predictive role of fecal calprotectin (FC) measured at an early stage of treatment for monitoring clinical remission (CR) after six months and endoscopic remission (ER) after one year of treatment in pediatric Crohn’s disease (CD).MethodsThis retrospective study included 45 patients who simultaneously underwent ileocolonoscopy and FC testing during follow-up. FC levels were measured before and after six weeks of treatment. CR was assessed after six months of treatment using Pediatric Crohn’ s Disease Activity Index and acute-phase reactants. ER was assessed after one year using the Simple Endoscopic Score for Crohn’s Disease.ResultsTwenty-nine (64.4%) patients used oral prednisolone for remission induction and 16 (35.6%) patients used anti-tumor necrosis factor-alpha. Thirty (66.7%) patients achieved CR, while 24 (53.3%) achieved ER. The FC level measured after six weeks of treatment could predict CR (χ2=9.15, p=0.0025) and ER (χ2=12.31, p=0.0004). The δFC could predict CR (χ2=7.91, p=0.0049), but not ER (χ2=1.85, p=0.1738). With a threshold of ≤950.4 µg/g, FC at week six could predict CR with 76.7% sensitivity and 73.3% specificity. The area under the curve (AUC) was 0.769 (standard error 0.0773, p=0.0005). The same threshold predicted ER with 87.5% sensitivity and 71.4% specificity. The AUC was 0.774 (standard error 0.074, p=0.0002).ConclusionFC assay at an early stage of treatment can be used as a surrogate marker to predict CR and mucosal healing in pediatric CD.

Small intestinal sampling capsule for inflammatory bowel disease type detection and management.

Although serum and fecal biomarkers (e.g., lactoferrin, and calprotectin) have been used in management and distinction between inflammatory bowel disease (IBD) and irritable bowel syndrome (IBS), none are proven to be a differential diagnostic tool between Crohn's disease (CD) and ulcerative colitis (UC). The main challenge with laboratory-based biomarkers in the stool test is the inability to indicate the location of the disease/inflammation in the gastrointestinal (GI) tract due to the homogenous nature of the collected fecal sample. For the first time, we have designed and developed a battery-free smart capsule that will allow targeted sampling of inflammatory biomarkers inside the gut lumen of the small intestine. The capsule is designed to provide a simple and non-invasive complementary tool to fecal biomarker analysis to differentiate the type of IBD by pinpointing the site of inflammatory biomarkers secretion (e.g., small or large bowel) throughout the GI tract. The capsule takes advantage of the rapid change from an acidic environment in the stomach to higher pH levels in the small intestine to dissolve a pH-sensitive polymeric coating as a means to activate the sampling process of the capsule within the small intestine. A swelling polyacrylamide hydrogel is placed inside the capsule as a milieu to collect the sampled GI fluid while also providing the required mechanical actuation to close the capsule once the sampling is completed. The hydrogel component along with the collected GI fluid can be easily obtained from the capsule through the screw-cap design for further extraction and analysis. As a proof of concept, the capsule's performance in sampling and extraction of bovine serum albumin (BSA) and calprotectin - a key biomarker of inflammation - was assessed within the physiologically relevant ranges. The ratio of extracted biomarkers relative to that in the initial sampling environment remained constant (∼3%) and independent of the sampling matrix in both in vitro and ex vivo studies. It is believed that the demonstrated technology will provide immediate impact in more effective IBD type differential diagnostic and treatment strategies by providing a non-invasive assessment of inflammation biomarkers profile throughout the digestive tract.

P226 Does faecal Calprotectin help differentiate inflammatory from fibrous stenosis in Crohn’s disease?

Abstract Background Digestive stenosis is the most common complication of Crohn’s disease. It can be either inflammatory or fibrous. The clinical, biological and especially morphological characteristics of the stenosis can help differentiate inflammatory stenosis from fibrous stenosis. The aim of our study was to evaluate the performance of fecal calprotectin (FC), a marker of intestinal inflammation, in identifying the type of stenosis. Methods A prospective study including all patients followed for Crohn’s disease in the Gastroenterology Department of Habib Thameur Hospital over a 6-month period from July 2020 to December 2020 was performed. Clinical, biological, endoscopic and radiological data were collected. The inflammatory nature of the stenosis was mainly retained according to radiological activity signs objectified by cross-sectional imaging. All patients were given a FC assay at the time of inclusion. FC was dosed by using the Bulhmann® FCAL ELISA technique. The statistical study was carried out using the SPSS software version 22.0 (p value significant if lower than 0.05). Results Fifty patients were included in our study (mean age 40.54 years [18–67] and sex ratio (M/F) = 1.77). The average evolution time of the disease was 8 years [6 months- 27 years]. The disease was ileal in 16 patients, colic in 4 patients and ileocolic in 30. Twenty patients (40%) had an intestinal stenosis whose location was: ileocaecal anastomosis (n=9), ileal (n=8) and colic (n=3). Multiple stenoses (colic and ileal) were noted in 3 patients. Fifteen patients were on medical treatment at the time of inclusion: 7 patients were on Infliximab, 5 were on azathioprine and 3 were on 5ASA. Digestive symptoms such as diarrhoea or subocclusive syndromes were noted in 7 patients. A biological inflammatory syndrome (CRP &amp;gt;10mg/L) was noted in 8 patients. Of the 20 stenoses included, 8 were of the inflammatory type (40%). In the presence of stenosis, the mean level of FC was 224.9 μg/g. A high level of FC was associated with the inflammatory type of stenosis (p&amp;lt;0.001). A cut-off of 135 µg/g had a sensitivity 100% and a specificity of 90%. CRP did not differentiate between inflammatory stenosis and fibrous stenosis (p=0.4). Conclusion According to our study, FC is a good marker of intestinal inflammation allowing to differentiate an inflammatory from a fibrous stenosis during Crohn’s disease better than the usual biological markers. These results should be confirmed by larger studies.

Analytical characteristics of faecal and serum calprotectin or calprotectin assay: What clinical interest?

Calprotectin is a calcium binding protein expressed at the inflammatory site by neutrophils and monocytes to activate the innate immune system. Thanks to this unique characteristic, it is a good indicator of local inflammation in chronic inflammatory rheumatism. All of the data highlight the key role that calprotectin plays in the inflammatory process in several inflammatory rheumatism. The value of serum and faecal calprotectin assays has been widely studied in recent years, in particular in rheumatoid arthritis, spondyloarthritis, juvenile idiopathic arthritis and vasculitis associated with ANCA but also for chronic inflammatory bowel disease. calprotectin has been identified as a powerful biomarker that allows the evaluation and monitoring of the activity of disease but also to predict structural evolution or response to treatment. Calprotectin is also a predictive biomarker of risk relapse. In this review, we discuss the value of calprotectin in chronic inflammatory affections as a diagnostic, potency or prognostic biomarker.

Analytical characteristics of faecal and serum calprotectin or calprotectin assay: What clinical interest?

Analytical characteristics of faecal and serum calprotectin or calprotectin assay: What clinical interest?

Can 2 Different Fecal Calprotectin Assays be Used Interchangeably in IBD Treatment?

Fecal calprotectin (FC) is a biomarker for inflammation in inflammatory bowel disease (IBD). Interpretation of results can be complicated because of the use of different assays to determine FC. To assess the agreement between 2 different assays for determining FC in patients with IBD. Samples from adults and children with IBD were tested with 2 assays: (1) EliA 2 Calprotectin and (2) EK-Cal. Samples were uniformly tested on the same day. Interassay variability was displayed in a Bland-Altman plot. The difference in categorization of the FC result (1: 0 to 250 mg/kg, 2: 250 to 500 mg/kg, 3: >500 mg/kg) was assessed with the linear weighted κ for adults and children separately. A total of 171 patients [mean age: 33 (range: 7 to 81); 92 (54%) female; 117 (68%) Crohn's disease; 53 (31%) ulcerative colitis] were included. Median (interquartile ranges) FC levels were 281 mg/kg (70 to 971) (EK-Cal) and 159 mg/kg (31 to 778) (EliA 2), and the mean delta FC was 89 mg/kg. In the adult population, there was substantial agreement between the 2 assays (κ: 0.72; SE: 0.06; 95% confidence interval, 0.60-0.83) and for pediatric patients, the agreement was almost perfect (κ: 0.83; SE: 0.06; 95% confidence interval: 0.70-0.95). Five of 171 patients (all aged ≥17 y and all with colonic disease) had a difference of 2 categories (1 vs. 3) between assays. Interassay variability was the highest in category 3. The agreement between the EliA 2 and EK-Cal assay in this cohort of IBD patients is substantial to almost perfect. Interassay variability is higher in the highest FC category.

Validation of the newly FDA-approved Buhlmann fCal Turbo assay for measurement of fecal calprotectin in a pediatric population

ObjectivesInflammatory bowel disease (IBD) is an increasingly prevalent disorder marked by chronic intestinal inflammation. Fecal calprotectin has emerged as a useful biomarker for differential diagnostics and monitoring IBD activity. We validated the newly FDA-approved fCal Turbo fecal calprotectin assay in our pediatric hospital. Design and methodsThe performance of the fCal Turbo assay was assessed on the Vitros 5600 analyzer (Ortho Clinical Diagnostics, USA), including limit of quantitation, linearity, precision, and interference studies. Method comparison was performed with 20 fecal samples with the Buhlmann fCal ELISA, and reference range verification was performed with 33 fecal samples. ResultsThe fCal Turbo assay on the Vitros 5600 was linear between 33.1 and 14,182.5 ​μg/g, with dilution studies extending the range to 33.1–22,000 ​μg/g, Reproducibility of the assay met acceptability criteria, with intra-assay CV of 0.3–3.2% and inter-assay CV of 5.2–8.9%. Interference studies identified acceptable thresholds for protein, bilirubin, and lipids. We verified a reference range of 33.1–60 ​μg/g in our patient population. Deming regression identified acceptable correlation with minor positive bias (2.7%) between the fCal Turbo and fCal ELISA methods. ConclusionsThe fCal Turbo assay performs well on the Vitros 5600 analyzer in our patient population, with the assay being easy to use in our routine chemistry workflow. We anticipate that the fCal Turbo assay will be useful as a rapid screening method for differential diagnostics and disease monitoring of IBD in our patient population.

A162 THE UTILITY OF FECAL CALPROTECTIN IN PREDICTING SEVERITY OF CLOSTRIDIUM DIFFICILE INFECTION: A SYSTEMATIC REVIEW

Abstract Background Clostridium difficile is an anaerobic, spore-forming, gram-positive bacillus, and a leading cause of infectious diarrhea in hospitalized patients. It is associated with high mortality and morbidity, and places an enormous burden on the healthcare system. Symptoms and severity of CDI vary widely, from illness that resolves with antibiotics, to toxic megacolon, colectomy, and death. The ability to risk-stratify patients to predict severe versus non-severe outcomes at baseline would be clinically useful. The role of fecal calprotectin in predicting severity of CDI has not been well established. Aims To perform a systematic review of the literature on the ability of fecal calprotectin to predict disease severity in patients with CDI. Methods PubMed, OVID (EMBASE/MedLine) and Cochrane Library databases were searched up until October 2, 2019. Publications of pediatric populations, Inflammatory Bowel diseases, and those only published as abstracts were excluded. Results 130 non-duplicate citations were screened; after title/abstract screening, and full-text review, 7 articles were included for analysis. Articles were from 2014 onwards, and varied from 29 to 232 patients/samples analyzed; 832 patients in total were analyzed. Three studies were conducted in the USA, two in Europe, one in Israel and in South Korea. Four studies were prospective, and the remaining three were retrospective cohort studies. There was significant heterogeneity between studies with respect to population size, age (when reported), fecal calprotectin assay and cutoff used, method of diagnosis of CDI, and criteria for defining disease severity. There was wide variation in median fecal calprotectin levels between studies. Four studies demonstrated a statistically significant difference of fecal calprotectin according to disease severity, and three did not, of which two of these demonstrated an overall predictive trend with fecal calprotectin. Conclusions It is unclear whether fecal calprotectin is predictive of severity of CDI in adult patients without IBD. In the existing literature, there seems to be a statistically significant association or trend towards association in most studies, but due to heterogeneity of methods, assays, cutoffs and populations, the data within these studies cannot be pooled in meta-analysis. Further high-powered, well-designed studies are required to clarify this important clinical question. Funding Agencies None