Improved assay for fecal calprotectin

Fecal Calprotectin for the Diagnosis and Management of Inflammatory Bowel Diseases

Calprotectin is a heterodimeric calcium- and zinc-binding protein mainly derived from the cytoplasm of neutrophils that has direct antimicrobial functions and a role in the regulation of the innate immune response. It can be found in various biological compartments, in particular, the stool, with concentrations related to the level of mucosal inflammation. The measurement of fecal calprotectin has thus been recognized as a useful surrogate marker to distinguish patients with inflammatory bowel disease from those with irritable bowel syndrome. Moreover, it allows the monitoring of intestinal inflammation with a high negative predictive value, making it possible to exclude the diagnosis of inflammatory bowel disease for symptomatic patients. It also shows high sensitivity for the identification of patients requiring additional examinations for diagnosis, such as colonoscopy, and the evaluation of therapeutic responses, providing evidence of relapse or mucosal healing, which can lead to the intensification or reduction of treatment. As calprotectin levels are a measure of mucosal inflammation, high fecal concentrations are also found in other diseases with an inflammatory component, such as infectious enteritis or colorectal cancer. Interpretation of the concentration must therefore always take into account the clinical history and symptoms specific to each patient.

Fecal Calprotectin in Gastrointestinal Disease

BACKGROUND

Inflammatory bowel disease (IBD) comprises a group of chronic conditions characterized by relapsing and remitting inflammation of the gastrointestinal tract. The incidence is increasing worldwide, and the therapeutic options for management are expanding. Endoscopy is the gold standard investigation for diagnosis of IBD and for assessing mucosal healing, which is increasingly being used as a measure of disease control. However, it is an invasive procedure that is unpleasant for patients and expensive and time-consuming for hospitals. Fecal calprotectin has been shown to be an accurate surrogate marker of gastrointestinal inflammation in IBD.

CONTENT

Fecal calprotectin was initially used for the diagnosis of IBD but is now recognized as having a role in assisting in assessment of disease activity, prediction of relapse, and informing decisions around therapy and may help to minimize requirement for endoscopy. However, there are various preanalytical and analytical factors that can affect interpretation of the results; these need to be understood to optimize clinical care.

SUMMARY

Preanalytical and analytical factors that can potentially influence fecal calprotectin concentrations are examined, and an overview is provided of clinical situations in which fecal calprotectin is commonly measured.

The Reliability of Patient-Performed Fecal Calprotectin Testing in Inflammatory Bowel Disease

BACKGROUND

Home use of a buffer-containing extraction device for fecal calprotectin determination can bypass the labor-intensive extraction procedure and potentially prevent degradation at room temperature.

METHODS

In this prospective cross-sectional observational study, 2 CALiaGold tubes (extraction device) and one native tube were filled from the same bowel movement by patients with inflammatory bowel disease. Afterwards patients completed a questionnaire including whether they preferred the extraction device or the normal sampling method. All tubes were sent to the laboratory and when they arrived, 2 more CALiaGold tubes were filled at the laboratory from the native sample. The fecal calprotectin concentrations in all tubes were measured by a particle-enhanced turbidimetric immunoassay.

RESULTS

Fifty-three patients were included in the study. Fecal calprotectin levels were significantly higher in samples extracted by the patient compared to the analyst-performed extractions. When patients were divided into 3 groups (i.e., fecal calprotectin levels <50 ug/g, 50 to 200 µg/g, and >200 µg/g) a substantial concordance was found (Cohen kappa 0.654). Patients sampling imprecision was higher (P < 0.018, median CV 16%) compared to the analyst. Most patients preferred this extraction device.

CONCLUSIONS

Patient-performed fecal calprotectin extraction seems a realistic alternative sampling method and is preferred by most patients.

Mobile genetic elements from the maternal microbiome shape infant gut microbial assembly and metabolism

The perinatal period represents a critical window for cognitive and immune system development, promoted by maternal and infant gut microbiomes and their metabolites. Here, we tracked the co-development of microbiomes and metabolomes from late pregnancy to 1 year of age using longitudinal multi-omics data from a cohort of 70 mother-infant dyads. We discovered large-scale mother-to-infant interspecies transfer of mobile genetic elements, frequently involving genes associated with diet-related adaptations. Infant gut metabolomes were less diverse than maternal but featured hundreds of unique metabolites and microbe-metabolite associations not detected in mothers. Metabolomes and serum cytokine signatures of infants who received regular-but not extensively hydrolyzed-formula were distinct from those of exclusively breastfed infants. Taken together, our integrative analysis expands the concept of vertical transmission of the gut microbiome and provides original insights into the development of maternal and infant microbiomes and metabolomes during late pregnancy and early life.

Can dysplasia surveillance be better targeted in ulcerative colitis by using faecal calprotectin?

Background: In the inflammatory bowel diseases, chronic inflammation predisposes to dysplasia and colorectal carcinoma, leading to the need of surveillance colonoscopies. The most-used marker of colonic inflammation is faecal calprotectin. Its correlation with endoscopic and histological findings is well-documented. In this study, we evaluated the role of sequential faecal calprotectin measurements in predicting colorectal dysplasia, to identify patients with increased risk of dysplasia or colonic malignancy in ulcerative colitis.Methods: We collected the faecal calprotectin measurements and colorectal histology reports of patients with ulcerative colitis treated in Helsinki University Hospital (Helsinki, Finland) between 2007 and 2017, with a focus on IBD-associated neoplasia, inflammatory activity, and sporadic adenomas. Using the time-weighted AUC of faecal calprotectin as a marker of inflammatory burden, we tested the performance of faecal calprotectin to predict the risk for colorectal neoplasia.Results: In total, 982 patients with ulcerative colitis were included. Of them, 845 had pancolitis and 127 concomitant primary sclerosing cholangitis. Forty-one patients (4%) had IBD-associated colorectal dysplasia and seven (0.7%) developed adenocarcinoma. In patients with constantly elevated faecal calprotectin level (>500 µg/g), colorectal neoplasia was more frequent compared to those with low (<200 µg/g) calprotectin (13% and 4%, p < 0.05). Histological inflammatory activity was also related to more frequent dysplastic changes.Conclusions: Colon dysplasia and adenocarcinoma are more common among ulcerative colitis patients with constantly elevated faecal calprotectin than in patients in remission. The role of inflammatory activity in inducing neoplastic changes in colon is further supported by histology, as histological inflammatory activity correlates with dysplasia.

Clinical evaluation of the OC-Sensor Pledia calprotectin assay

Objectives

Faecal calprotectin (f-Cal) and faecal haemoglobin (f-Hb) are important tests for evaluation of gastrointestinal disease. Samples for measurement of f-Hb are taken by the patient directly into a specimen collection device containing stabilising buffer, which can be placed directly onto the analyser in the laboratory. Samples for f-Cal are usually sent in screw top pots and often require time-consuming extraction procedures prior to analysis. OC-FCa calprotectin is a new assay which uses the same specimen collection device and analyser as our current f-Hb assay. Analytical evaluation has already shown it to perform well but to have a positive bias. This study was a clinical evaluation to investigate the diagnostic test performance and cut-off suitable for its use in the diagnosis of IBD.

Methods

OC-FCa calprotectin was measured in a convenience sample of 603 patients in whom f-Hb had been requested and was found to be ≥10 μg/g. Clinical outcomes were obtained from notes, radiological reports and endoscopy and histology reports.

Results

A total of 425 patients completed clinical investigations; IBD was diagnosed in 49 and other colorectal pathology in 161. Median f-Cal in patients with IBD was 1,660 μg/g, significantly different (p<0.01) from those with other colorectal pathology (192 μg/g) or normal findings (157 μg/g). ROC curve analysis showed AUC of 0.898 with sensitivity of 91.8% and specificity of 79.3% at a cut-off of 600 μg/g.

Conclusions

The new OC-FCa calprotectin assay performed well for the diagnosis of IBD using a cut-off of 600 μg/g.

Impact of Preanalytical Factors on Calprotectin Concentration in Stool: A Multiassay Comparison

Background

Measuring calprotectin concentration in stool is increasingly important in monitoring disease activity and treatment response in inflammatory bowel disease. This study evaluates the impact of preanalytical storage conditions on reliability of calprotectin testing using 5 different calprotectin immunoassays.

Methods

Aliquots of homogenized fresh fecal samples in untreated or extracted form were stored at room temperature or 4°C. Calprotectin concentration was measured day 0 to 4 and 8. Five different immunoassays and accompanying extraction buffers were used (CALiaGold, Phadia EliA, Bühlmann fCal turbo, ELISA Bühlmann, Inova Quanta Flash). Repeated measurements of change from baseline calprotectin levels over time were analyzed using a mixed model analysis.

Results

Calprotectin concentrations declined over time under all preanalytical conditions with all assays, except for extracted feces stored at 4°C. The rate of decline was greatest in untreated stool kept at room temperature, reaching significant difference from baseline already after 1 day (P &lt; 0.001). In extracted feces kept at room temperature, significant difference from baseline was reached after 2 days, and in untreated feces at 4°C, after 4 days. However, the results differed significantly between assays. After 4 days of storage at room temperature, the mean calprotectin decline from baseline differed between 30% and 60%, dependent on the assay used.

Conclusions

Fecal calprotectin concentration in stool samples declines over time, and the rate of decline is greater at higher temperatures. In extracted feces stored at 4°C, calprotectin is most stable. It is assay-dependent how long extracted feces stored at 4°C give reliable test results.

Therapeutic Potential of Quercetin Loaded Nanoparticles: Novel Insights in Alleviating Colitis in an Experimental DSS Induced Colitis Model

Oxidative stress is considered the main etiologic factor involved in inflammatory bowel disease (IBD). Integration of nanocarriers for natural therapeutic agents with antioxidant and anti-inflammatory potential is a novel promising candidate for curing IBD. Herein, the colonic antioxidant and anti-inflammatory effects of different concentrations of quercetin nanoparticles (QT-NPs) were evaluated using a dextran sulfate sodium (DSS)-induced colitis model. Following colitis induction, the efficacy and mechanistic actions of QT-NPs were evaluated by assessing lesion severity, molecular aids controlling oxidative stress and inflammatory response, and histopathological and immunohistochemistry examination of colonic tissues. Administration of QT-NPs, especially at higher concentrations, significantly reduced the disease activity index and values of fecal calprotectin marker compared to the colitic group. Colonic oxidant/antioxidant status (ROS, H₂O₂, MDA, SOD, CAT, GPX and TAC) was restored after treatment with higher concentrations of QT-NPs. Moreover, QT-NPs at levels of 20 mg/kg and, to a lesser extent, 15 mg/kg reduced Nrf2 and HO-1 gene expression, which was in line with decreasing the expression of iNOS and COX2 in colonic tissues. Higher concentrations of QT-NPs greatly downregulated pro-inflammatory cytokines; upregulated genes encoding occludin, MUC-2 and JAM; and restored the healthy architectures of colonic tissues. Taken together, these data suggest that QT-NPs could be a promising alternative to current IBD treatments.

Estimation of Titanium Dioxide Intake by Diet and Stool Assessment among US Healthy Adults

BACKGROUND

Titanium dioxide (TiO2/E171) is used in foods primarily as a whitening agent. Little is known regarding TiO2 exposure in the United States.

OBJECTIVES

To quantify stool TiO2 content among US adults and evaluate its association with estimated intake.

METHODS

Adults participated in phase 1 [three 24-h dietary recalls (DRs) and stool TiO2 measured from 3 matched samples (n = 52)] and/or phase 2 [tailored FFQ and stool TiO2 measured from 3 samples over 3 mo (n = 61)]. TiO2 in foods was estimated from a database, and concentration in 49 additional foods and 339 stool samples were quantified using inductively coupled plasma mass spectrometry. Associations between dietary and stool TiO2 were assessed by log-linear multivariable regression. USDA food groups (n = 49, servings/d) were related to stool TiO2 by stepwise regression.

RESULTS

TiO2 food content varied by brand. Mean TiO2 intake from three 24-h DRs [0.19 ± 0.31 mg/(kg body weight · d)] was lower than from the FFQ [0.30 ± 0.21 mg/(kg body weight · d)]. Dietary TiO2 was not predictive of stool TiO2, in phase 1 or phase 2, 10^(β) per 10 times higher dietary TiO2: 1.138 [10^(95% CI): 0.635, 2.037, P = 0.66] and 0.628 [10^(95% CI): 0.206, 1.910, P = 0.41], respectively. Food groups related to stool TiO2 were 1) milk desserts, sauces, and gravies [10^(β) per servings/d: 3.361; 10^(95% CI): 0.312, 36.163; P = 0.002] and 2) yeast breads [10^(β): 1.430; 10^(95% CI): 0.709, 2.884; P = 0.002] in phase 1 and 1) cream and cream substitutes [10^(β) = 10.925; 10^(95% CI): 1.952, 61.137; P = 0.01] and 2) milk and milk drinks [10^(β) = 0.306; 10^(95% CI): 0.086, 1.092, P = 0.07] in phase 2.

CONCLUSIONS

Intake of certain foods was associated with higher stool TiO2 content. There is a need for valid estimation of TiO2 intakes via the improvement of a dietary assessment method and a TiO2 food composition database. Future research should assess whether high stool TiO2 content is related to adverse health outcomes.

Multi-Strain-Probiotic-Loaded Nanoparticles Reduced Colon Inflammation and Orchestrated the Expressions of Tight Junction, NLRP3 Inflammasome and Caspase-1 Genes in DSS-Induced Colitis Model

Gut modulation by multi-strain probiotics (MSPs) is considered an effective strategy for treating inflammatory bowel disease (IBD). The combination of nanomaterial-based MSPs can improve their viability and resistance and can allow their targeted release in the gastrointestinal tract to be achieved. Thus, our aim is to investigate the prospective role of MSP integration into nanomaterials (MSPNPs) and the underlying molecular mechanisms supporting their application as an alternative therapy for IBD using a colitis rat model. To induce the colitis model, rats received 5% DSS, and the efficacy of disease progression after oral administration of MSPNPs was assessed by evaluating the severity of clinical signs, inflammatory response, expressions of tight-junction-related genes and NLRP3 inflammasome and caspase-1 genes, microbial composition and histopathological examination of colonic tissues. The oral administration of MSPNPs successfully alleviated the colonic damage induced by DSS as proved by the reduced severity of clinical signs and fecal calprotectin levels. Compared with the untreated DSS-induced control group, the high activities of colonic NO and MPO and serum CRP levels were prominently reduced in rats treated with MSPNPs. Of note, colonic inflammation in the group treated with MSPNPs was ameliorated by downstreaming NLRP3 inflammasome, caspase-1, IL-18 and IL-1β expressions. After colitis onset, treatment with MSPNPs was more effective than that with free MSPs in restoring the expressions of tight-junction-related genes (upregulation of occludin, ZO-1, JAM, MUC and FABP-2) and beneficial gut microbiota. Interestingly, treatment with MSPNPs accelerated the healing of intestinal epithelium as detected in histopathological findings. In conclusion, the incorporation of MPSs into nanomaterials is recommended as a perspective strategy to overcome the challenges they face and augment their therapeutic role for treating of colitis.

Impact of Extensively Hydrolyzed Infant Formula on Circulating Lipids During Early Life

Background

Current evidence suggests that the composition of infant formula (IF) affects the gut microbiome, intestinal function, and immune responses during infancy. However, the impact of IF on circulating lipid profiles in infants is still poorly understood. The objectives of this study were to (1) investigate how extensively hydrolyzed IF impacts serum lipidome compared to conventional formula and (2) to associate changes in circulatory lipids with gastrointestinal biomarkers including intestinal permeability.

Methods

In a randomized, double-blind controlled nutritional intervention study (n = 73), we applied mass spectrometry-based lipidomics to analyze serum lipids in infants who were fed extensively hydrolyzed formula (HF) or conventional, regular formula (RF). Serum samples were collected at 3, 9, and 12 months of age. Child’s growth (weight and length) and intestinal functional markers, including lactulose mannitol (LM) ratio, fecal calprotectin, and fecal beta-defensin, were also measured at given time points. At 3 months of age, stool samples were analyzed by shotgun metagenomics.

Results

Concentrations of sphingomyelins were higher in the HF group as compared to the RF group. Triacylglycerols (TGs) containing saturated and monounsaturated fatty acyl chains were found in higher levels in the HF group at 3 months, but downregulated at 9 and 12 months of age. LM ratio was lower in the HF group at 9 months of age. In the RF group, the LM ratio was positively associated with ether-linked lipids. Such an association was, however, not observed in the HF group.

Conclusion

Our study suggests that HF intervention changes the circulating lipidome, including those lipids previously found to be associated with progression to islet autoimmunity or overt T1D.

Clinical Trial Registration

[Clinicaltrials.gov], identifier [NCT01735123].

The role of faecal calprotectin in diagnosis and staging of colorectal neoplasia: a systematic review and meta-analysis

Introduction

The presence of inflammation is a key hallmark of cancer and, plays an important role in disease progression and survival in colorectal cancer (CRC). Calprotectin detected in the faeces is a sensitive measure of colonic inflammation. The role of FC as a diagnostic test that may categorise patients by risk of neoplasia is poorly defined. This systematic review and meta-analysis aims to characterise the relationship between elevations of FC and colorectal neoplasia.

Methods

A systematic review was performed using the keywords (MESH terms) and a statistical and meta-analysis was performed.

Results

A total of 35 studies are included in this review. CRC patients are more likely than controls to have an elevated FC OR 5.19, 95% CI 3.12–8.62, p < 0.001 with a heterogeneity (I² = 27%). No tumour characteristics significantly correlated with FC, only stage of CRC shows signs that it may potentially correlate with FC.

Conclusion

FC levels are significantly higher in CRC, with high sensitivity. Its low specificity prevents it from being used to diagnose or screen for CRC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12876-022-02220-1.

Comparison of Next-Generation Assays for Fecal Calprotectin vs the PhiCal Assay

OBJECTIVES

To compare the PhiCal assay (CALPRO), the first US Food and Drug Administration-approved assay for fecal calprotectin, to 4 next-generation assays.

METHODS

Stool samples from 50 patients were selected, and relevant clinical information was collected. Comparisons were performed using the PhiCal, fCAL turbo (BÜHLMANN), LIAISON Calprotectin (DiaSorin), QUANTA Lite Calprotectin ELISA (Inova Diagnostics), and Calprotectin Chemiluminescence ELISA (ALPCO) assays.

RESULTS

All 4 assays had acceptable agreement with PhiCal when qualitatively categorizing results. Within the PhiCal reportable range of 16 to 1,250 μg/g, the DiaSorin, Inova Diagnostics, and ALPCO assays had Spearman correlation coefficients of 0.98, 0.97, and 0.95 and positive biases of 17%, 20%, and 15%, respectively. The BÜHLMANN assay ran approximately 2-fold higher than the PhiCal assay but had a correlation coefficient of 0.98, with similar result categorization.

CONCLUSIONS

Our results demonstrate good comparison between PhiCal and 4 next-generation assays. Laboratories performing fecal calprotectin assays may have compelling reasons to adopt next-generation fecal calprotectin testing, such as greater automation, a decreased number of replicates needed per test, and the use of stool-extraction devices. These benefits could decrease turnaround times and lower costs. Although the results of the assays correlated, they are not standardized. Laboratories adopting the newer assays will need to further investigate their performance through validation studies.

Coculture Strategy for Developing Lactobacillus paracasei PS23 Fermented Milk with Anti-Colitis Effect

Few studies have documented the effects of fermented milk on intestinal colitis, which are mediated by regulating various microbial and inflammatory processes. Here, we investigated the effects of fermented milk with Lactobacillus paracasei PS23 on intestinal epithelial cells in vitro and dextran sulfate sodium (DSS)-induced colitis in vivo. As L. paracasei PS23 grew poorly in milk, a coculture strategy with yogurt culture was provided to produce fermented milk (FM). The results indicated that the coculture exhibited a symbiotic effect, contributing to the better microbial and physicochemical property of the fermented milk products. We further evaluated the anti-colitis effect of fermented milk with L. paracasei PS23 in vitro. Both PS23-fermented milk (PS23 FM) and its heat-killed counterpart (HK PS23 FM) could protect or reverse the increased epithelial permeability by strengthening the epithelial barrier function in vitro by increasing transepithelial electrical resistance (TEER). In vivo analysis of the regulation of intestinal physiology demonstrated that low-dose L. paracasei PS23-fermented ameliorated DSS-induced colitis, with a significant attenuation of the bleeding score and reduction of fecal calprotectin levels. This anti-colitis effect may be exerted by deactivating the inflammatory cascade and strengthening the tight junction through the modification of specific cecal bacteria and upregulation of short-chain fatty acids. Our findings can clarify the role of L. paracasei PS23 in FM products when cocultured with yogurt culture and can elucidate the mechanisms of the anti-colitis effect of L. paracasei PS23 FM, which may be considered for therapeutic intervention.

Immunomodulatory assessment of Portulaca oleracea L. extract in a mouse model of colitis

Ulcerative colitis (UC) is a gastrointestinal inflammatory disease with a multifactorial pathophysiology. This study aims to investigate the immunomodulatory effect of Portulaca oleracea leaf ethanolic extract (POE) on acetic acid (AA)-induced UC in mice. Experimental animals received oral doses of POE (200 mg/kg for 7 days) after an induction of colitis by intrarectal AA administration. In mice with AA-induced UC treated with POE, the results revealed a significant modulation in body weight and colon length. Moreover, treatment with POE downregulated the interleukin 1, 6, and 17, tumor necrosis factor-alpha, gamma interferon, and nuclear factor-kappa B levels compared with the colitis group. Furthermore, POE markedly inhibited histological damage, decreased myeloperoxidase activity and reduced fecal calprotectin level compared with the colitis group. These data are consistent with the reduction in total bacterial content in the colon. Taken together, treatment with POE may reduce colonic inflammation by alleviating the immune response and inhibiting the severity of colitis. The HPLC analysis of POE resulted in the identification of seven medicinal compounds comprising two phenolic acids (ferulic and caffeic acids) and five flavonoids (kaempferol, quercetin, rutin, narenginin and hesperidin). Subsequent analysis of POE by GC-MS revealed ten phytocomponents; the major percentages were hexadecenoic acid, methyl ester (29.8119%), α-linolenic acid (25.8431%), 16-octadecenoic acid, methyl ester (15.1578%) and α-tocopherol (10.7848%). Delta-lactams and alkanes were the minor components. Such natural plant-derived substances and their probable synergistic action appear to contribute to a promising therapeutic protocol for colitis.

Investigation of asymptomatic intestinal inflammation in ankylosing spondylitis by fecal calprotectin

BACKGROUND AND STUDY AIMS

This study aimed to investigate the prevalence of intestinal inflammation in patients with ankylosing spondylitis (AS) by assessing fecal calprotectin (FC) levels and comparing them with those in patients with rheumatoid arthritis (RA) and non-inflammatory rheumatic diseases. Our secondary aim was to correlate FC levels with antirheumatic treatment, nonsteroidal anti-inflammatory drug (NSAID) usage, and disease activity measures.

PATIENTS AND METHODS

This cross-sectional study included 97 patients with AS fulfilling the modified New York criteria, 48 patients with RA fulfilling the American College of Rheumatology criteria, and 49 patients with non-inflammatory rheumatic diseases. All patients were questioned about intestinal complaints, and symptomatic patients were excluded. Disease activity was measured in the AS and RA patient groups.

RESULTS

The AS group had a significantly higher FC test positivity rate than the RA group (p = 0.016). Furthermore, the AS group had FC levels that were negatively correlated with disease duration (p = 0.04). FC levels were not correlated with any disease activity index, erythrocyte sedimentation rate, C-reactive protein, uveitis, or peripheral arthritis. Patients with AS who used NSAIDs had significantly higher FC levels than nonusers (p = 0.001).

CONCLUSIONS

This study revealed that 11% of patients with AS without intestinal complaints had elevated FC levels. FC levels were not correlated with disease activity in AS. Subclinical intestinal inflammation was higher in the early stages of AS. The AS group had a significantly higher FC test positivity than the RA group. In the AS group, NSAID users had significantly higher FC levels than nonusers; thus, no statistically significant difference was observed between biological agent users and nonusers.

Fecal calprotectin is a useful biomarker for predicting the clinical outcome of granulocyte and monocyte adsorptive apheresis in ulcerative colitis patients: a prospective observation study

Background

Granulocyte and monocyte adsorptive apheresis (GMA) is widely used as a remission induction therapy for active ulcerative colitis (UC) patients. However, there are no available biomarkers for predicting the clinical outcome of GMA. We investigated the utility of Fecal calprotectin (FC) as a biomarker for predicting the clinical outcome during GMA therapy in active UC patients.

Methods

In this multicenter prospective observation study, all patients received 10 sessions of GMA, twice a week, for 5 consecutive weeks. FC was measured at entry, one week, two weeks, and at the end of GMA. Colonoscopy was performed at entry and after GMA. The clinical activity was assessed based on the partial Mayo score when FC was measured. Clinical remission (CR) was defined as a partial Mayo score of ≤ 2 and endoscopic remission (ER) was defined as Mayo endoscopic subscore of either 0 or 1. We analyzed the relationships between the clinical outcome (CR and ER) and the change in FC concentration.

Result

Twenty-six patients were included in this study. The overall CR and ER rates were 50.0% and 19.2%, respectively. After GMA, the median FC concentration in patients with ER was significantly lower than that in patients without ER (469 mg/kg vs. 3107 mg/kg, p = 0.03). When the cut-off value of FC concentration was set at 1150 mg/kg for assessing ER after GMA, the sensitivity and specificity were 0.8 and 0.81, respectively. The FC concentration had significantly decreased by one week. An ROC analysis demonstrated that the reduction rate of FC (ΔFC) at 1 week was the most accurate predictor of CR at the end of GMA (AUC = 0.852, P = 0.002). When the cut-off value of ΔFC was set at ≤ 40% at 1 week for predicting CR at the end of GMA, the sensitivity and specificity were 76.9% and 84.6%, respectively.

Conclusion

We evaluated the utility of FC as a biomarker for assessing ER after GMA and predicting CR in the early phase during GMA in patients with active UC. Our findings will benefit patients with active UC by allowing them to avoid unnecessary invasive procedures and will help establish new strategies for GMA.

The Use of Fecal Calprotectin Testing in Paediatric Disorders: A Position Paper of the European Society for Paediatric Gastroenterology and Nutrition Gastroenterology Committee

OBJECTIVES

The aim of the study was to review the evidence regarding the clinical use and value of fecal calprotectin (FC) measurements in different gastrointestinal disorders in children.

METHODS

A literature search was conducted in the PubMed, MEDLINE, EMBASE, and Cochrane databases until October 31, 2019. Subtopics were identified and each assigned to individual authors.

RESULTS

A total of 28 recommendations were voted on using the nominal voting technique. Recommendations are given related to sampling, measurement methods, and results interpretation. The 14 authors anonymously voted on each recommendation using a 9-point scale (1 strongly disagree to 9 fully agree). Consensus was considered achieved if at least 75% of the authors voted 6, 7, 8, or 9.

CONCLUSIONS

Consensus was reached for all recommendations. Limitations for the use of FC in clinical practice include variability in extraction methodology, performance of test kits as well as the need to establish local reference ranges because of the influence of individual factors, such as age, diet, microbiota, and drugs. The main utility of FC measurement at present is in the diagnosis and monitoring of inflammatory bowel disease (IBD) as well as to differentiate it from functional gastrointestinal disorders (FAPDs). FC, however, has neither utility in the diagnosis of infantile colic nor to differentiate between functional and organic constipation. A rise in FC concentration, may alert to the risk of developing necrotizing enterocolitis and help identifying gastrointestinal involvement in children with Henoch-Schönlein purpura. FC measurement is of little value in Cow's Milk Protein Allergy, coeliac disease (CD), and cystic fibrosis. FC does neither help to distinguish bacterial from viral acute gastroenteritis (AGE), nor to diagnose Helicobacter Pylori infection, small intestinal bacterial overgrowth (SIBO), acute appendicitis (AA), or intestinal polyps.

Clinical and Analytical Verification of an Automated Fecal Calprotectin Immunoassay with Extraction Device

BACKGROUND

Fecal calprotectin (FC) is a screening test for intestinal inflammation, and often used by clinicians to help identify and monitor patients with inflammatory bowel disease (IBD). Improvements in FC assays include moving to more automated immunoassays compared to ELISAs and simple-to-use extraction devices compared to manual weighing for the extraction process.

METHODS

A method comparison was performed between the PhiCal ELISA and LIAISON immunoassay for 53 stool samples, and the screening results were compared to the gold standard endoscopy with biopsy results. Clinical accuracy was assessed by comparing the FC results from each assay to the presence or absence of inflammation determined from the biopsy report. The performance of the extraction device was compared to manually weighing. Additional studies were completed to verify the manufacturer's claims.

RESULTS

The FC results were compared to the biopsy results for detecting inflammation. PhiCal ELISA had a sensitivity of 86% and specificity of 100%, while the LIAISON immunoassay had a sensitivity of 97% with specificity of 94%. Therefore, the LIAISON immunoassay performed better than the PhiCal ELISA. The extraction device performed well compared to manual weighing if stool samples were <800 μg/g, within Bristol stool types 2-6, and did not contain a significant amount of undigested material, fibrous material, or mucus.

CONCLUSION

The LIAISON immunoassay with extraction device has acceptable performance for clinical use in measuring fecal calprotectin.

Identification of microRNA-16-5p and microRNA-21-5p in feces as potential noninvasive biomarkers for inflammatory bowel disease

BACKGROUND

Inflammatory bowel disease (IBD) is a chronic idiopathic gastrointestinal disease. Increasing evidence suggests that microRNAs (miRNAs) may participate in the pathophysiology of IBD.

METHODS

A miRCURY™ LNA Array and in situ hybridization were employed to screen for differentially expressed miRNAs (DEMs) in fecal specimens from 41 IBD patients (22 ulcerative colitis (UC), 19 Crohn's disease (CD)) and 23 healthy controls (HC). RT-qPCR was performed to confirm the findings. The DEMs target genes and corresponding biological functions were predicted by bioinformatics analysis.

RESULTS

Compared with HC, miR-16-5p in the feces was up-regulated both in UC and CD patients (p < 0.01), while miR-21-5p was up-regulated only in UC patients (p < 0.01). TargetScan 7.2, miRWalk, and miRDB were used to predict 216 public target genes of miR-16-5p and miR-21-5p, and six hub genes (PIK3R1, GRB2, SUZ12, NTRK2, Smurf2, and WWP1) were analyzed using the STRING database and Cytoscape. All the hub genes promote the occurrence and development of IBD-related colorectal cancer.

CONCLUSIONS

The elevated levels of miR-16-5p and miR-21-5p in feces of IBD patients have to guide significance for the noninvasive clinical diagnosis of IBD and have a warning effect on the occurrence of IBD-related colorectal cancer.

Non-IgE- or Mixed IgE/Non-IgE-Mediated Gastrointestinal Food Allergies in the First Years of Life: Old and New Tools for Diagnosis

non-IgE and mixed gastrointestinal food allergies present various specific, well-characterized clinical pictures such as food protein-induced allergic proctocolitis, food protein-induced enterocolitis and food protein-induced enteropathy syndrome as well as eosinophilic gastrointestinal disorders such as eosinophilic esophagitis, allergic eosinophilic gastroenteritis and eosinophilic colitis. The aim of this article is to provide an updated review of their different clinical presentations, to suggest a correct approach to their diagnosis and to discuss the usefulness of both old and new diagnostic tools, including fecal biomarkers, atopy patch tests, endoscopy, specific IgG and IgG4 testing, allergen-specific lymphocyte stimulation test (ALST) and clinical score (CoMiss).

A Practical Guide for Faecal Calprotectin Measurement: Myths and Realities

BACKGROUND AND AIMS

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Faecal calprotectin and gut microbiota do not predict enteropathy in very preterm infants

Aim

Very preterm birth is associated with a high risk of enteropathies. Diagnosis is challenging, especially in mild forms, leading to unnecessary periods of cessation of enteral feeding. This study aimed at establishing a prognosis score of enteropathy combining clinical parameters and faecal calprotectin concentration.

Methods

This prospective multicentric study included preterm neonates born at a gestational age of 33 weeks or less. Stools were collected weekly until hospital discharge, and daily in case of digestive events for calprotectin measurement (ELISA and immunochromatography) and microbiota analyses (16S rRNA gene sequencing).

Results

Among the 121 neonates included, 21 experienced at least one episode of enteropathy, mainly mild forms. By ELISA testing, median faecal calprotectin was 88 (8‐798) µg/g faeces. No statistically significant association was found between the outset of enteropathy and maternal and neonatal characteristics, and calprotectin levels. The agreement between ELISA and immunochromatography assay was moderate (intra‐class correlation coefficient 0.58, 95%CI [0.47‐0.66]). Comparison of species diversity and relative bacterial abundance profiles between infants with or without enteropathy revealed no specific alterations associated with enteropathy.

Conclusion

The study failed to propose a prognostic score of enteropathy, probably due the large inter‐ and intra‐individual variability of faecal calprotectin in very preterm neonates.

Global Studies of Using Fecal Biomarkers in Predicting Relapse in Inflammatory Bowel Disease

Inflammatory bowel disease (IBD) is a chronic inflammatory condition of the gastrointestinal tract mainly comprising two forms including Crohn's disease (CD) and ulcerative colitis (UC). IBD is a lifelong relapsing remitting disease and relapses occur at random patterns which are unpredictable. Fecal biomarkers have been increasingly used to assess disease activity in IBD due to their positive correlations with intestinal inflammation. Recent studies have also assessed the use of fecal biomarkers in predicting relapse and post-operative recurrence. This review provides information from global studies of using fecal calprotectin, lactoferrin and S100A12 to predict relapse in IBD. Strategies for further studies and the use of these fecal biomarkers for personalized management in IBD are also discussed.

Fecal calprotectin in healthy children aged 4-16 years

Reference values of fecal calprotectin (fCP) have not been convincingly established in children. We aimed to investigate fCP concentrations in a larger population of healthy children aged 4–16 years to analyze more in depth the behavior of fCP in this age range and to determine if cut-off levels could be conclusively recommended. A prospective study was conducted to investigate fCP concentrations of healthy children aged 4–16 years. In 212 healthy children, the median and 95th percentile for fCP were 18.8 mg/kg and 104.5 mg/kg, respectively. We found a statistically significant association between the 95th percentile of fCP concentrations and age (p < 0.001). We propose a nomogram to facilitate the interpretation of fCP results in children aged 4–16 years. Further studies are required to validate the proposed values in clinical practice.

Faecal calprotectin levels during the first year of life in healthy children

AIM

A high faecal calprotectin (FC) level is a non-invasive marker for inflammatory bowel disease. Nevertheless, healthy infants have elevated levels of FC with large variations. The aim of our study was to determine the levels of FC and associated factors in healthy infants aged 0-12 months.

METHODS

Infants younger than 1 year of age were in the follow-up programme of the Well Child Unit. Data on the clinical characteristics, including birth, anthropometric measurements and feeding types of infants in the unit, were obtained from their personal health records. One fresh stool sample was collected from each infant. ELISA was used to measure FC.

RESULTS

We included 84 infants younger than 1 year of age. The median FC value was 313 μg/g. The FC levels were greater in the youngest (0-30 days) group of infants than in the oldest (181-365 days) group (P < 0.001). The FC levels were higher in infants delivered by caesarean section than in those delivered vaginally (P = 0.016). The levels were also higher in infants who were solely breastfed than in those who received mixed feeding (breast milk and formula) during the first 6 months of life (P = 0.030).

CONCLUSION

The FC levels in this group of infants were high, especially in the first month of life. Several birth and environmental factors influenced the FC values. Further studies with a larger cohort of infants and serial assessment of FC over time are required to better understand the patterns of this biomarker during infancy.

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

Objectives

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

Design

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

Results

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

Conclusions

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

•

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

•

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

•

Differences observed between immunoassays are due to lack of standardization.

•

Blood in the stool can effect the calprotectin measurement.

The Accuracy of a Home-performed Faecal Calprotectin Test in Paediatric Patients With Inflammatory Bowel Disease

OBJECTIVES

Owing to the invasiveness of endoscopy, the use of biomarkers, especially faecal calprotectin (FC), has become standard for remission assessment. This study aimed to compare the accuracy for detection of endoscopic activity using recently developed FC home test using smartphone application (FC-IBDoc) against standard enzyme-linked immunosorbent assay (ELISA).

METHODS

In all, 102 consecutive observations (89 participants) were included in prospective observational study. FC-IBDoc was performed parallelly with FC-ELISA in paediatric patients with inflammatory bowel disease indicated for endoscopy. Both tests were performed by trained staff. Mucosal healing was defined using Simple Endoscopic Score for Crohn disease (CD) ≤2 in patients with CD (n = 44), ulcerative colitis (UC) Endoscopic Index of Severity ≤4 in patients with UC (n = 27) and Rutgeerts score i0 and i1 without colon involvement in patients with CD after ileocaecal resection (n = 19).

RESULTS

Out of 102 endoscopic findings 23 were assessed as mucosal healing. We found an association of the mucosal healing scores of the entire group both with FC-ELISA (P = 0.002) and FC-IBDoc (P = 0.001). The area under the receiver operating characteristic curve for FC-ELISA was 0.883 (95% confidence interval 0.807-0.960), with optimal cut-off at 136.5 μg/g. The area under the receiver operating characteristic curve for FC-IBDoc was 0.792 (95% confidence interval 0.688-0.895) with optimal cut-off at 48 μg/g. The FC-ELISA was more accurate than FC-IBDoc when tested by a Delong test (P = 0.023).

CONCLUSIONS

Standard FC-ELISA for FC evaluation is more reliable predictor of mucosal healing than the FC-IBDoc in paediatric patients with inflammatory bowel disease. The cut-off values for both tests were incongruous.

Clinical value of fecal calprotectin

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

Faecal calprotectin determination: impact of preanalytical sample treatment and stool consistency on within- and between-method variability

Introduction

We assessed the differences in faecal calprotectin (FC) concentrations measured by two assays depending on the stool consistency and extraction method.

Materials and methods

Stool samples were extracted using the EliA Stool Extraction Kit, Calex® Cap extraction device and respective weighing methods, while FC concentrations were measured using the EliA^TM Calprotectin and Bühlmann fCAL® Turbo method and checked for within- and between-method variability with regard to extraction method and stool consistency category. Extraction yield was evaluated for impact of different sample incubation time (10 min and 1 h) in extraction buffer for both methods and for impact of different initial sample dilutions (1:50, 1:100, 1:500) for fCAL® Turbo method.

Results

Results determined from Calex® Cap extracts were higher compared to weighing method extracts (mean bias 33.3%; P < 0.001), while no significant difference was found between results obtained with EliA Stool Extraction Kit and weighing method (mean bias 0.1%; P = 0.484), in both cases irrespective of stool consistency. Bühlmann fCAL® Turbo results were higher than EliA^TM Calprotectin results (mean bias 32.3%, P = 0.025 weighing method; and mean bias 53.9%, P < 0.001 extraction devices), the difference is dependent on stool consistency and FC concentration. Significantly higher FC extraction yield was obtained with longer sample incubation time for both methods (P = 0.019 EliA^TM Calprotectin; P < 0.001 fCAL® Turbo) and with increasing initial sample dilution for fCAL® Turbo method (P < 0.001).

Conclusion

Preanalytical stool sample handling proved to be a crucial factor contributing to within- and between-FC assay variability. Standardization is urgently needed in order to assure comparable and reliable FC results.

The role of fecal calprotectin in pediatric disease

Fecal calprotectin (FC) is a calcium- and zinc-binding protein of the S100 family, mainly expressed by neutrophils and released during inflammation. FC became an increasingly useful tool both for gastroenterologists and for general practitioners for distinguishing inflammatory bowel disease (IBD) from irritable bowel syndrome. Increasing evidences support the use of this biomarker for diagnosis, follow-up and evaluation of response to therapy of several pediatric gastrointestinal diseases, ranging from IBD to nonspecific colitis and necrotizing enterocolitis. This article summarizes the current literature on the use of FC in clinical practice.

Preventive effect of ecabet sodium on low-dose aspirin-induced small intestinal mucosal injury: a randomized, double-blind, pilot study

Background

We aimed to investigate how high-dose ecabet sodium affects low-dose aspirin-induced small intestinal mucosal injury in healthy volunteers.

Methods

Healthy volunteers were enrolled randomly into one of two groups with the following drug regimens for 2 weeks: group A, low-dose aspirin once per day and group B, low-dose aspirin and 4.0 g of ecabet sodium. Small bowel capsule endoscopy was performed before and 2 weeks after low-dose aspirin administration.

Results

A significant difference was found in the median number [range] of small intestinal lesions between baseline and two weeks after low-dose aspirin administration in group A (baseline: 1 [0–5], after: 5 [1–11]; p = 0.0059) but not in group B (baseline: 0.5 [0–9], after: 3 [0–23]; p = 0.0586). In group B, although the median number [range] of lesions in the first tertile of the small intestine did not increase two weeks after low-dose aspirin administration (baseline: 0 [0–4], after: 1.5 [0–8]; p = 0.2969), the number of lesions in the second and third tertiles of the small intestine increased significantly (baseline: 0 [0–5], after: 2 [0–15]; p = 0.0469).

Conclusions

Ecabet sodium had a preventive effect on low-dose aspirin-induced small intestinal mucosal injury in the upper part of the small intestine.

Trial registration

ISRCTN 99322160, 01/10/2018.

Accuracy of Consecutive Fecal Calprotectin Measurements to Predict Relapse in Inflammatory Bowel Disease Patients Under Maintenance With Anti-TNF Therapy: A Prospective Longitudinal Cohort Study

BACKGROUND AND GOAL

Predicting relapse in inflammatory bowel disease (IBD) patients could allow early changes in therapy. We aimed at evaluating the accuracy of consecutive fecal calprotectin (FC) measurements to predict flares in IBD patients under maintenance treatment with anti-tumor necrosis factor (TNF) drugs.

STUDY

A prospective longitudinal cohort study with 16-month follow-up period was designed. IBD patients in clinical remission for at least 6 months under anti-TNF therapy were included. FC was quantified at 4-month intervals for 1 year, and patients were clinically evaluated for relapse at 2-month intervals. Diagnostic accuracy of FC for predicting relapse was evaluated by receiver-operating characteristic curve analysis.

RESULTS

In total, 95 of 106 included patients finalized the study and were analyzed (median age 44 y, 50.5% female, 75% with Crohn's disease). A total of 30 patients (31.6%) had a relapse over follow-up. FC concentration was significantly higher in patients who relapsed (477 μg/g) than in patients who maintained in remission (65 μg/g) (P<0.005). The optimal cutoff to predict remission was 130 μg/g (negative predictive value of 100%), and 300 μg/g to predict relapse (positive predictive value of 78.3%).

CONCLUSIONS

FC is a good predictor of clinical relapse and a particularly good predictor of remission over the following 4 months in patients with IBD on maintenance therapy with anti-TNF drugs. FC levels <130 μg/g is consistently associated with maintained disease remission, whereas concentrations >300 μg/g allow predicting relapse with a high probability at any time over the following 4 months.

Fecal Calprotectin

Calprotectin is a 36kDa member of the S100 family of proteins. It is derived predominantly from neutrophils and has direct antimicrobial effects and a role within the innate immune response. Calprotectin is found in various body fluids in proportion to the degree of any existing inflammation and its concentration in feces is about six times that of plasma. Measurement of fecal calprotectin is a useful surrogate marker of gastrointestinal inflammation. It has a high negative predictive value in ruling out inflammatory bowel disease (IBD) in undiagnosed, symptomatic patients and a high sensitivity for diagnosing the disease making it useful as a tool for prioritising endoscopy. In patients with known IBD, fecal calprotectin can be a useful tool to assist management, providing evidence of relapse or mucosal healing to enable therapy to be intensified or reduced. There are a number of commercial calprotectin assays with marked difference in performance as judged by external quality assessment and at present no standardised reference material exists. Various factors may affect results including age, medication and day to day variation. Laboratories should therefore be mindful of the characteristics of their own assay and factors that may affect results.

Fecal Calprotectin and Eosinophil-derived Neurotoxin in Healthy Children Between 0 and 12 Years

OBJECTIVES

In young children, the use of fecal calprotectin (fCP) as a biomarker is limited because reference values have not been widely accepted up to now. Moreover, reference values for fecal eosinophil-derived neurotoxin (fEDN) in children have not been established. The aim of the present study was to investigate fCP and fEDN levels in young healthy children to establish reference values.

METHODS

Stool samples were obtained from healthy children ages 0 to 12 years. fCP and fEDN levels were analyzed using the EliA Calprotectin 2 assay (Phadia AB) and a novel research assay (on the ImmunoCAP platform), respectively.

RESULTS

In the 174 included children (87 boys), 95th Percentile values ranged from 1519 mg/kg at 0 months to 54.4 mg/kg at 144 months for fCP and from 9.9 mg/kg at 0 months to 0.2 mg/kg at 144 months for fEDN. There was a statistically significant association between age and fCP concentrations (P < 0.001) and age and fEDN concentrations (P < 0.001). We also found a statistically significant association between fEDN and fCP concentrations (rho = 0.52, P < 0.001). According to our results, we provide a nomogram and we suggest 3 different age groups for evaluation of fCP and fEDN concentrations, the 95th percentile being respectively 910.3 and 7.4 mg/kg for 0-12 months, 285.9 and 2.9 mg/kg for >1 to 4 years, and 54.4 and 0.2 mg/kg for >4 to 12 years.

DISCUSSION

By using an improved analytical method, we have confirmed that young healthy children have higher fCP concentrations than healthy adults. We, for the first time, report reference values for fEDN concentrations in a pediatric population. The proposed nomograms and reference values for fCP and fEDN are aimed at facilitating the applicability of biomarkers for both neutrophil- and eosinophil-mediated intestinal inflammation in children in clinical practice.

Analytical and diagnostic performance of two automated fecal calprotectin immunoassays for detection of inflammatory bowel disease

BACKGROUND

We evaluated the (pre-)analytical and diagnostic performance of two automated fecal calprotectin (FC) immunoassays, Liaison® Calprotectin (Diasorin) on Liaison® XL and fCAL™ turbo (Bühlmann laboratories AG) on Cobas C501 (Roche Diagnostics), and compared it with our established Bühlmann ELISA method.

METHODS

Our study comprised 229 consecutive patients with clinical suspicion of inflammatory bowel disease (IBD).

RESULTS

All assay related stool extraction procedures showed excellent correlation with the established method, but the new stool extraction devices tend to give higher results as compared with stool weight methods. Both automated assays demonstrated good performance in terms of precision (CVt≤8.1%), accuracy (bias≤6.7%) and total error (≤16.4%). Method comparison with established enzyme linked immunosorbent assay (ELISA) showed good correlation (rs>0.925), but regression analysis showed significant proportional differences. Diagnostic performance characteristics with regard to diagnosis of IBD were good and in line with other reports. In addition, we were able to show that optimization of manufacturer's cut-off and moreover, the introduction of a gray zone resulted in a significant increase of post-test probability.

CONCLUSIONS

In conclusion, the newly developed stool extraction device protocols showed acceptable and comparable performance to the stool weight method. Overall, the automated Liaison® Calprotectin and fCAL™ turbo assay showed good analytical and diagnostic performance for detection of IBD.

Effect of faecal calprotectin assay variability on the management of inflammatory bowel disease and potential role of faecal S100A12

Aims

To prospectively evaluate whether between-assay variability of different faecal calprotectin (f-Cp) assays influences diagnostic accuracy for inflammatory bowel disease (IBD) in a cohort of patients with confirmed IBD and irritable bowel syndrome (IBS). To also evaluate the diagnostic accuracy of faecal S100A12 (f-S100A12) against f-Cp in the same patient cohort and assess whether f-S100A12 offers additional diagnostic value.

Methods

F-Cp using four commercially available f-Cp assays, f-S100A12 and blood biomarkers were measured in patients, recruited from the local IBD clinic, who had established IBS or active ulcerative colitis (UC) and Crohn’s disease (CD). Diagnostic sensitivities and specificities for each assay and biomarker were calculated and compared.

Results

Median f-Cp levels in all assays were significantly higher in UC (347–884 µg/g; n=28) and CD (377–838 µg/g; n=15) compared with IBS (6–27 µg/g; n=17). Sensitivities and specificities at 50 µg/g were 94%–100% and 82%–100%, respectively. Median f-S100A12 levels were significantly higher in UC (81.0 µg/g; IQR 38.3–159.8) and CD (47.2 µg/g; IQR 5.3–108.9) compared with IBS (0.7 µg/g; IQR 0.5–0.8). At 2.8 µg/g, f-S100A12 had a sensitivity of 97% and specificity of 94%. The blood biomarkers demonstrated sensitivities and specificities of 44%–63% and 80%–92%, respectively.

Conclusions

The diagnostic sensitivity of the calprotectin assays was similar despite inter-kit variability in absolute values. There is a need for f-Cp assay standardisation, but in its absence assay-specific cut-off values may optimise their diagnostic performance. F-S100A12 demonstrated comparable sensitivity and specificity to f-Cp and although a research tool at present, may have a future role to play in the diagnosis and management of these patients.

Comparison of non-invasive biomarkers faecal BAFF, calprotectin and FOBT in discriminating IBS from IBD and evaluation of intestinal inflammation

Faecal calprotectin and faecal occult blood test (FOBT) were widely used in the diagnosis and assessment of intestinal inflammation in inflammatory bowel disease (IBD). Recently we identified an excellent new biomarker B cell-activating factor (BAFF) for IBD. Here in this study we compared the efficacy of faecal BAFF, calprotectin and FOBT to find the “best non-invasive marker”. Results showed that for discriminating IBD from IBS, BAFF ≥227.3 pg/ml yield 84% sensitivity, 100% specificity, 100% positive predictive value (PPV) and 64% negative predictive value (NPV) while calprotectin ≥50 µg/g yield 76% sensitivity, 93% specificity, 97% PPV and 53% NPV. FOBT yield 65% sensitivity, 93% specificity, 97% PPV and 43% NPV. Combining BAFF with calprotectin tests yield 94% sensitivity, 93% specificity, 98% PPV, 81% NPV. Faecal BAFF level showed the stronger correlation with endoscopic inflammatory score as compared to calprotectin not only in UC (correlation coefficient [r] = 0.69, p < 0.0001 vs. r = 0.58, p < 0.0001), but also in CD (r = 0.58, p < 0.0001 vs. r = 0.52, p = 0.0003). Our results indicating that faecal BAFF is a promising non-invasive biomarker in IBD differential diagnosis and monitoring of intestinal inflammation.

Fecal calprotectin in inflammatory bowel diseases: update and perspectives

Inflammatory bowel diseases (IBDs) are chronic diseases that result from the inflammation of the intestinal wall, suspected in any patient presenting with intestinal symptoms. Until recently, the diagnosis was mainly based on both clinical and endoscopic arguments. The use of an easy, fast, reliable, non-invasive, and inexpensive biological assay is mandatory not only in diagnosis but also in evolutionary and therapeutic monitoring. To date, the fecal calprotectin is the most documented in this perspective. This marker allows the discrimination between functional and organic bowel processes with good performance. The determination of the fecal calprotectin level contributes to the evaluation of the degree of disease activity and to monitoring of therapeutic response.

A prospective study of fecal calprotectin and lactoferrin as predictors of small bowel Crohn's disease in patients undergoing capsule endoscopy

BACKGROUND

Capsule endoscopy (CE) is often used to investigate small bowel Crohn's disease (CD).

AIM

The aim of this study is to prospectively assess the value of fecal calprotectin and lactoferrin to predict CE findings.

PATIENTS AND METHODS

Sixty-eight consecutive patients that were referred for CE were included. Stool samples for calprotectin and lactoferrin and blood samples were collected for relevant parameters. Correlation between fecal markers and CE findings was assessed and receiver operating characteristic (ROC) curves were built to determine the predictive values of fecal markers for the diagnosis of CD.

RESULTS

Fecal calprotectin data was available for all the patients and lactoferrin data for 38. CE findings compatible with CD were found in 23 (33%) patients and 45 (67%) were negative for CD. The average age of the CD group was 34 compared to 46 in the non-CD group (p = .048). Median calprotectin and lactoferrin in the CD group and in the control group were 169 mg/kg vs. 40 (p = .004) and 6.6 mg/kg vs. 1 (p = .051), respectively. The area under the ROC curve was 0.767 for calprotectin and 0.70 for lactoferrin. A fecal calprotectin concentration of 95 mg/kg and fecal lactoferrin of 1.05 mg/kg had a sensitivity, specificity, positive predictive value and negative predictive value of 77 and 73%, 60 and 65%, 50 and 50%, and 84 and 84% in predicting CE findings compatible with CD.

CONCLUSIONS

Fecal markers are simple and noninvasive surrogates for predicting CE findings compatible with CD. Fecal markers can help determine which patients should be referred for CE. ClinicalTrials.gov Identifier: NCT01266629.

Clinical implications of assay specific differences in f-calprotectin when monitoring inflammatory bowel disease activity over time

OBJECTIVE

With several faecal calprotectin (FC) assays on the market, it has been difficult to define a uniform threshold for discriminating between remission and active disease in patients with inflammatory bowel disease (IBD). We aimed to compare the results of different FC-assays in IBD patients, followed over time.

MATERIAL AND METHODS

IBD patients provided faecal samples and reported clinical activity every third month prospectively over a two year period. FC was measured with two ELISA - (Bühlmann and Immunodiagnostik) and one automated fluoroimmunoassay (Phadia).

RESULTS

In total, 13 patients provided 91 faecal samples. The median (IQR) concentration of FC was higher at active disease than at remission for all assays: Bühlmann 845 (1061-226) μg/g versus 62 (224-39) μg/g, Phadia 369 (975-122) μg/g versus 11 (52-11) μg/g, and Immundiagnostik 135 (302-69) μg/g versus 8 (56-4) μg/g. The Bühlmann assay produced the largest absolute difference but the corresponding relative difference seemed to be more pronounced when analysed by the Phadia - (ratio of means 8.5; 95% CI 3.3-21.9) or the Immundiagnostik assay (ratio of means 7.4; 95% CI 3.1-17.6) than by the Bühlmann assay (ratio of means 5.3; 95% CI 2.7-10.6). Consequently, the specificity for discriminating active disease from remission varied between assays (34-75%) when the cut-off 50 μg/g was used, whereas the differences in sensitivity were less pronounced.

CONCLUSIONS

Cross-comparisons revealed overall poor agreement between the assays as well as differences in the dynamics of FC. These findings suggest that standardisation of the method is needed to implement FC as a disease monitoring tool at large-scale.

Patient-performed extraction of faecal calprotectin

BACKGROUND

Faecal (f-) calprotectin is a widely used marker for intestinal inflammation. However, extraction procedure is time consuming and cumbersome. The main aim of this study was to evaluate patient-performed extraction of f-calprotectin compared to extraction performed in the laboratory.

METHODS

A total of 81 adult patients with an established diagnosis of inflammatory bowel disease provided two samples from the same bowel movement, one conventional faeces sample and one sample with a patient administered extraction device. A laboratory technician extracted the conventional faeces sample with the same extraction device.

RESULTS

F-calprotectin results from the laboratory-performed extraction and the patient-performed extraction correlated significantly, with a Spearman rank correlation coefficient of 0.92. Method comparison showed a slope of 1.20 (95% confidence interval 1.08-1.36) with intercept of -0.30 (95% confidence interval -9.00 to 4.62). This demonstrates a small proportional difference between the results from the home extracted samples and the results from the laboratory extracted samples, where the home extracted samples are slightly higher. However, six of the 81 patients had made obvious mistakes in the extraction process and their samples were excluded from the study.

CONCLUSIONS

Patient administered extraction of f-calprotectin can be a realistic alternative for selected patients. However, instructions must be very precise to avoid mistakes.

Diagnosing colorectal cancer and inflammatory bowel disease in primary care: The usefulness of tests for faecal haemoglobin, faecal calprotectin, anaemia and iron deficiency. A prospective study

OBJECTIVE

Abdominal complaints are common reasons to consult primary care but they are seldom caused by colorectal cancer (CRC), high-risk adenomas (HRAs), or inflammatory bowel disease (IBD). Reliable diagnostic aids would be helpful in deciding which patients to refer for bowel imaging. Our aim was to assess the value of a faecal immunochemical test (FIT) and a faecal calprotectin (FC) test in detecting CRC, HRAs and IBD in primary care, and the value of combining these tests with anaemia and iron-deficiency tests.

MATERIALS AND METHODS

This prospective study included 373 consecutive patients that received a FIT or a FC test ordered by a primary care physician. We collected samples for FITs, FC tests, full blood counts and iron-deficiency tests. Physicians were instructed to refer patients with a positive FIT or FC test (cut-off ≥100μg/g) for bowel imaging. The patients' presenting symptoms were recorded. Patients were followed for 2 years.

RESULTS

The best test for detecting CRC and IBD was the combination of the FIT and haemoglobin concentration. This test had a sensitivity, specificity, positive predictive value and negative predictive value of 100%, 61.7%, 11.7% and 100%, respectively. The FIT detected a significantly larger proportion of CRC, HRAs and IBD than the FC test (0.92 versus 0.46, 95% confidence interval 0.22-0.67).

CONCLUSION

A negative FIT combined with a normal haemoglobin concentration could rule out CRC and IBD with a high degree of safety. This could be useful in prioritising referrals for bowel imaging from primary care.

Patients with longstanding ulcerative colitis in remission do not have more irritable bowel syndrome-like symptoms than controls

Background

Irritable bowel syndrome (IBS) is more common in patients with ulcerative colitis (UC) than expected. The prevalence of IBS in patients with UC with longstanding disease is not known. We investigated the prevalence of IBS-like symptoms in patients with UC in remission and longstanding disease in comparison to control subjects.

Methods

Sixty-eight patients with UC and 33 patients with hereditary familiar colon cancer and who underwent colonoscopy surveillance were included. Faecal calprotectin (FC), Gastrointestinal Symptoms Rating Scale-Irritable Bowel Syndrome (GSRS-IBS) and Hospital Anxiety and Depression scale were fulfilled prior to endoscopy. UC in remission was define by steroid-free clinical remission, a Mayo Score ≤ 1 on endoscopy, a FC ≤ 200 μg/g and no significant active inflammation on colon biopsies.

Results

Fifty-five UC patients met the criteria for being in remission. The median disease duration was 17 years. The patients with UC in remission tended to have lower scores on total GSRS-IBS score (6 vs 10.5; p = 0.062) and lower or equal scores on all specific IBS symptoms in comparison to controls. There was a moderate but significant correlation between diarrhoea scores and FC levels (in the span ≤ 200 μg/g) (rs 0.38; p = 0.004) in the UC in remission group.

Conclusion

Patients with UC with longstanding disease and in remission do not have more IBS symptoms than controls. In UC patients in remission the FC level in the lower span showed a moderate correlation to symptoms of diarrhoea.

Electronic supplementary material

The online version of this article (doi:10.1186/s12876-016-0553-x) contains supplementary material, which is available to authorized users.

Usefulness of a rapid faecal calprotectin test to predict relapse in Crohn's disease patients on maintenance treatment with adalimumab

BACKGROUND AND AIM

Predicting relapse in Crohn's disease (CD) patients by measuring non-invasive biomarkers could allow for early changes of treatment. Data are scarce regarding the utility of monitoring calprotectin to predict relapse. The aim of the study was to evaluate the predictive value of a rapid test of faecal calprotectin (FC) to predict for flares in CD patients on maintenance treatment with adalimumab (ADA).

METHODS

A prospective, observational cohort study was designed. Inclusion criteria were CD patients in clinical remission on a standard dose of ADA therapy. Fresh FC was measured using a rapid test.

RESULTS

Thirty patients were included (median age 38 years, 56.7% female). After the 4 months follow-up, 70.0% patients remained in clinical remission and 30.0% had a relapse. FC concentration at inclusion was significantly higher in those patients who relapsed during the follow-up (625 μg/g) compared to those who stayed in remission (45 μg/g). The optimal cut-off for FC to predict relapse was 204 μg/g. The area under the receiver-operating characteristic curve was 0.968. Sensitivity, specificity, positive, and negative predictive value of FC to predict relapse were 100%, 85.7%, 74.1%, and 100%, respectively.

CONCLUSION

In CD patients on ADA maintenance therapy, FC levels measured with a rapid test allow relapse over the following months to be predicted with high accuracy. Low FC levels exclude relapse within at least 4 months after testing, whereas high levels are associated with relapse in three out of every four patients.

Clinical importance of faecal calprotectin variability in inflammatory bowel disease: intra-individual variability and standardisation of sampling procedure

OBJECTIVE

Faecal (f-) calprotectin is a biomarker of intestinal inflammation. Previous studies have described intra-individual day-to-day variability of this biomarker in patients with inflammatory bowel disease (IBD) and morning samples have been suggested for standardisation purposes. With this project, we investigated if day-to-day variability differed from diurnal variability. Additionally, we evaluated a new extraction method for f-calprotectin analysis.

METHODS

Fifty patients provided three faeces samples from morning - evening - morning on two consecutive days. Nineteen patients provided two faeces samples from the same bowel movement, one conventional spot sample, and one sample with a device for patient-administered sampling and extraction.

RESULTS

The two morning samples differentiated between mucosal inflammation and mucosal healing with same level of agreement as the two samples from the same day (kappa 0.76), using an f-calprotectin cut-off level of 259 μg/g. Although large intra-individual variation in f-calprotectin values, there were no significant day-to-day (p = 0.096) or diurnal variation (p = 0.78). Used by laboratory technicians, the new extraction device correlated significantly with the conventional extraction method (p < 0.001), Spearman's rank correlation coefficient 0.95. Of the 19 patients testing patient administered extraction, two patients provided samples leading to considerably higher f-calprotectin levels than conventional sampling procedure.

CONCLUSIONS

The reliability of f-calprotectin morning samples is equal to the reliability of samples from different bowel movements on the same day. The new extraction method is reliable when used by laboratory technicians, but larger studies are recommended to evaluate patient administered extraction.

Determination of the adequate dosage of rebamipide, a gastric mucoprotective drug, to prevent low-dose aspirin-induced gastrointestinal mucosal injury

Small intestinal mucosal injury caused by low-dose aspirin is a common cause of obscure gastrointestinal bleeding. We aimed to investigate the protective effects and optimal dose of rebamipide for low-dose aspirin-induced gastrointestinal mucosal injury. In this prospective randomized trial, 45 healthy volunteers (aged 20–65 years) were included and divided into three groups. The groups received enteric-coated aspirin 100 mg (low-dose aspirin) plus omeprazole 10 mg (Group A: proton pump inhibitor group), low-dose aspirin plus rebamipide 300 mg (Group B: standard-dose group), or low-dose aspirin plus rebamipide 900 mg (Group C: high-dose group). Esophagogastroduodenoscopy and video capsule endoscopy were performed, and the fecal occult blood reaction and fecal calprotectin levels were measured before and two weeks after drug administration. Although the fecal calprotectin levels increased significantly in Group A, they did not increase in Groups B and C. The esophagogastroduodenoscopic and video capsule endoscopic findings and the fecal occult blood test findings did not differ significantly among the three groups. In conclusion, standard-dose rebamipide is sufficient for preventing mucosal injury of the small intestine induced by low-dose aspirin, indicating that high-dose rebamipide is not necessary.