Fecal calprotectin in pediatric inflammatory bowel disease: a systematic review

Performance of fecal S100A12 as a novel non-invasive diagnostic biomarker for pediatric inflammatory bowel disease: a systematic review and meta-analysis

OBJECTIVE

The incidence and prevalence of inflammatory bowel disease (IBD) in pediatric patients are increasing. Currently, the diagnostic method for IBD is inconvenient, expensive, and difficult. S100A12, a type of calcium-binding protein, detected in the feces of patients with IBD has recently been suggested as a promising diagnostic tool. Hence, the authors aimed to evaluate the accuracy of fecal S100A12 in diagnosing IBD in pediatric patients by performing a meta-analysis.

METHODS

The authors performed a systematic literature search in five electronic databases for eligible studies up to July 15, 2021. Pooled diagnostic accuracies of fecal S100A12 were analyzed as the primary outcomes. Secondary outcomes were standardized mean difference (SMD) of fecal S100A12 levels between IBD and non-IBD groups and a comparison of diagnostic accuracies between fecal S100A12 and fecal calprotectin.

RESULTS

Seven studies comprising 712 children and adolescents (474 non-IBD controls and 238 IBD cases) were included. Fecal S100A12 levels were higher in the IBD group than in the non-IBD group (SMD = 1.88; 95% confidence interval [CI] = 1.19-2.58; p < 0.0001). Fecal S100A12 could diagnose IBD in pediatric patients with a pooled sensitivity of 95% (95% CI = 88%-98%), specificity of 97% (95% CI = 95%-98%), and area under the receiver operating summary characteristics (AUSROC) curve of 0.99 (95% CI = 0.97-0.99). Fecal S100A12 specificity and AUSROC curve values were higher than those of fecal calprotectin (p < 0.05).

CONCLUSION

Fecal S100A12 may serve as an accurate and non-invasive tool for diagnosing pediatric IBD.

The use of calgranulin-C (S100A12) and fecal zonulin as possible non-invasive markers in children with inflammatory bowel disease: a clinical study

Calgranulin-C (S100A12) and zonulin are considered markers of intestinal inflammation. Our aim was to evaluate fecal S100A12 (f-S100A12) and fecal zonulin (f-zonulin) in children with inflammatory bowel disease (IBD), compared to fecal calprotectin (FC) and serum inflammatory markers. We enrolled children with a previous diagnosis of Crohn's disease (CD) and ulcerative colitis (UC). F-S100A12, f-zonulin, and FC were determined by enzyme-linked immunosorbent assay (ELISA). Endoscopic examination was considered in the patients who underwent ileocolonoscopy within 2 weeks from the enrollment. One hundred seventeen children, 39.3% with CD and 60.7% with UC were enrolled. In both CD and UC, there was a significant direct correlation between FC and f-S100A12 levels. In children with CD and UC, both FC and f-S100A12 correlated with markers of serum inflammation. We found difference in FC and f-S100A12 levels between patients in clinical relapse and remission (FC: mean 1027 ± 818 mcg/ml vs 580 ± 695 mcg/ml respectively, p = 0.028; f-S100A12: mean 66.4 ± 48.2 mcg/ml vs 42.7 ± 40 mcg/ml, respectively p = 0.02). Moreover, we found difference in FC between children with endoscopic inflammation and remission (mean 825 ± 779 mcg/ml vs 473.3 ± 492 mcg/ml, respectively p = 0.048), as well as for f-S100A12 (53 ± 43 mcg/ml vs mean 31 ± 33 mcg/ml vs, respectively p = 0.019). No significant results were found for f-zonulin.

CONCLUSION

Our data suggest that f-S100A12 and FC are both useful non-invasive biomarkers in the management of pediatric IBD in follow up and in monitoring endoscopic and clinical relapse.

WHAT IS KNOWN

• Fecal calprotectin (FC), fecal S100A12 (f- S100A12), and fecal zonulin represent potential noninvasive markers of gut inflammation. • Since S100A12 is predominantly expressed by granulocytes, high levels of f-S100A12 should be more specific for inflammation than FC.

WHAT IS NEW

• FC and f-S100A12 were correlated to each other and despite the lack of correlation with disease location, they were associated with endoscopic inflammation and clinical relapse in children with IBD. • No significant correlations were found between f-zonulin and the inflammatory parameters.

Poor Concordance Between Clinical Activity and Endoscopic Severity in Pediatric Crohn's Disease: Before and After Induction Therapy

OBJECTIVES AND STUDY

Endoscopic assessments of disease activity are important to diagnose and evaluate treatment responses in patients with Crohn's disease (CD). However, the invasiveness of endoscopy limits the application of this technique in routine examination. Thus, interest has been increasing in identifying noninvasive surrogate markers to predict endoscopic CD activity.

METHODS

We retrospectively analyzed pediatric patients with new-onset CD from January 2013 to December 2018 at Zhejiang University Affiliated Children's Hospital. The disease severity was scored according to the Crohn's Disease Endoscopic Index of Severity (CDEIS). Routine blood tests were determined individually. Clinical activity was assessed based on the Pediatric Crohn's Disease Activity Index (PCDAI).

RESULTS

A total of 91 patients with CD had undergone one or more ileocolonoscopies (n = 146), the mean CDEIS for all the pediatric patients with CD was 7.0 (95% CI 5.7-8.2), and the mean PCDAI was 20.9 (95% CI 18.3-23.5). Pearson's linear analysis of the CDEIS and PCDAI in pediatric patients with CD showed a moderate correlation (r = 0.508, P < 0.001). Weak correlations were found between the PCDAI and CDEIS at the first diagnosis (r = 0.408, P < 0.001) and after completing induction therapy (r = 0.286, P < 0.05). Routine blood tests also did not correlate well with the CDEIS.

CONCLUSIONS

This study identified weak correlations between the PCDAI and CDEIS in assessing pediatric patients with CD severity both at first diagnosis and after induction therapy. A comprehensive assessment of PCDAI, CDEIS and multiple laboratory factors should be performed at diagnosis and during the follow-up of patients with CD.

Association between autism spectrum disorder and inflammatory bowel disease: A systematic review and meta-analysis

Children with autism spectrum disorder (ASD) are frequently diagnosed with co-occurring medical conditions including inflammatory bowel disease (IBD). To investigate the association, we conducted a systematic review registered in PROSPERO (ID:CRD42021236263) with a random-effects meta-analysis. We searched PubMed, Embase, and PsycInfo (last search on January 25, 2021), and manually searched relevant publications. We included observational studies measuring the association between ASD and IBD. The primary outcome was the association (odds ratio, OR) between ASD and later development of IBD. Sensitivity analyses were conducted by quality, confounding adjustment, and study design. We performed meta-regression analyses and assessed heterogeneity, publication bias, and quality of studies with the Newcastle-Ottawa Scale. Overall, we included six studies consisting of eight datasets, including over 11 million participants. We found that ASD was significantly associated with subsequent incident IBD (any IBD, OR = 1.66, 95% confidence interval[CI] = 1.25-2.21, p < 0.001; ulcerative colitis, OR = 1.91, 95%CI = 1.41-2.6, p < 0.001; Crohn's disease, OR = 1.47, 95%CI = 1.15-1.88, p = 0.002). ASD and IBD were also associated regardless of temporal sequence of diagnosis (any IBD, OR = 1.57, 95%CI = 1.28-1.93, p < 0.001; ulcerative colitis, OR = 1.7, 95%CI = 1.36-2.12, p < 0.001; Crohn's disease, OR = 1.37, 95%CI = 1.12-1.69, p = 0.003). Sensitivity analyses confirmed the findings of the main analysis. Meta-regression did not identify any significant moderators. Publication bias was not detected. Quality was high in four datasets and medium in four. In conclusion, our findings highlight the need to screen for IBD in individuals with ASD, and future research should identify who, among those with ASD, has the highest risk of IBD, and elucidate the shared biological mechanisms between ASD and IBD.

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.

Guidance on the interpretation of faecal calprotectin levels in children

BACKGROUND

Faecal calprotectin (FCP) is a powerful tool to predict inflammatory bowel disease (IBD) in patients with gastrointestinal symptoms. In the paediatric patient population, the reference value of < 50 μg/g and the influence of age on FCP levels result in a high number of redundant investigations and specialist referrals. We assessed paediatric FCP levels, their diagnostic value and corresponding referral pathways from primary and secondary care.

METHODS

We analysed two cohorts from a precisely defined catchment area: one consisted of all FCPs measured in this area (n = 2788). The second cohort-a subset of the first cohort-consisted of FCP values and corresponding clinical data from children who were referred for possible IBD to our department (n = 373).

RESULTS

In the first cohort, 47% of FCP levels were > 50 μg/g, 15% were ≥ 250 μg/g. Children < 1y had significantly (p < 0.001) higher FCP than older children. In the second cohort, 6.7% of children with an FCP of < 250 μg/g (or 8.6% with an FCP of < 600 μg/g) had IBD-all featured symptoms suggestive of IBD (e.g. bloody diarrhoea, nocturnal abdominal pain, weight loss) or abnormal blood tests. 76% of patients in whom raised FCP (> 50 μg/g) was the sole reason for being referred for suspected IBD did not have IBD.

CONCLUSION

Children with an FCP < 600 μg/g and without matching symptoms suggestive of IBD are unlikely to have IBD. A higher FCP reference value may provide cost-effective improvement that could avoid redundant investigations and specialist referrals. A guideline for specialist referrals is proposed.

Laboratory Assessment of Disease Activity in Pediatric Patients with Inflammatory Bowel Disease: What’s New?

Laboratory tests are an integral part of both the diagnostic and follow-up algorithm of patients with inflammatory bowel disease (IBD). Their advantages over other non-invasive methods for assessing disease activity are greater objectivity than clinical activity indices and imaging studies. This review aims to analyze shortly the most common laboratory tests used to assess disease activity in pediatric patients with IBD. In addition to the conventional blood and serum markers that are not specific for gut inflammation, although routinely used, we also reviewed the established fecal markers such as calprotectin, lactoferrin, M2-pyruvate kinase, osteoprotegerin, HMGB1, chitinase 3-like 1, and the promising non-coding microRNA. In conclusion, neither marker is unique to the pediatric IBD. More clinical data are required to assess biomarkers’ full potential for diagnosis, management, and follow-up of pediatric IBD patients.

Faecal calprotectin in inflammatory bowel diseases: a review focused on meta-analyses and routine usage limitations

A growing body of evidence has been published about the usefulness of measuring calprotectin in faecal samples (FCAL) in inflammatory bowel disease (IBD) assessment, including diagnosis, monitoring of disease activity and relapse prediction. Several systematic reviews with meta-analyses compiling studies for each particular clinical setting have been carried out in recent years. Most of these were focused on the use of FCAL in IBD diagnosis and showed a relevant role for this marker in selecting patients with gastrointestinal symptoms who would not need a further examination by endoscopy. Although a lesser number of meta-analyses have been performed on the use of FCAL as a surrogate marker of disease activity, a close correlation between FCAL and endoscopic activity of IBD has been shown. With respect to the predictive capacity of FCAL for IBD relapse, a single meta-analysis published indicates that this role is more limited. Furthermore, FCAL thresholds vary considerably depending on the clinical setting and, what is more concerning, among different commercially available assays due to a lack of FCAL concentration interchangeability. Here, we summarise recent publications about the role and limitations of FCAL in IBD, with a special focus on meta-analyses, and give an overview of alternative faecal biomarkers.

Labordiagnostik bei chronisch‑entzündlichen Darmerkrankungen

Die Labordiagnostik hat sowohl im empfohlenen initialen „work up“ bei Verdacht auf eine chronisch entzündliche Darmerkrankung (CED) wie auch für das Monitoring des Krankheitsverlaufs und des Therapieansprechens einen klar umrissenen Stellenwert: Mithilfe der „Basislaborparameter“ wie z. B. Blutkörperchensenkungsgeschwindigkeit (BSG) können krankheitsspezifische Aktivitätsindizes erstellt werden, und neue serologische Marker (u. a. ANCA [„antineutrophil cytoplasmic antibodies“], ASCA [„anti-saccharomyces cerevisiaeantibodies“]) dienen der ergänzenden Differenzierung der CED-Entitäten. Derzeit dürfte das Stuhl-Calprotectin – als am weitreichendsten untersuchter fäkaler Inflammationsmarker – v. a. aufgrund der hohen Sensitivität initial und zur Einschätzung der Krankheitsaktivität der relativ beste Surrogatmarker sein. Nach wie vor ist aber die endoskopisch-histopathologische Evaluierung nicht nur für die Diagnose unabdingbar, sondern auch bezüglich des erklärten Therapieziels des „mucosal healing“, also im Rahmen der präzisen Verlaufsdokumentation. Der Entwicklung weniger invasiver „Biomarker“, die möglichst gut mit dem Schleimhautbefund korrelieren, kommt besondere Bedeutung zu, um die derzeit oft noch notwendige invasive Reevaluierung verringern zu helfen. Wie die Wertigkeit sowohl in der Routine etablierter, aber auch neuer, teils experimentell angewandter serologischer, fäkaler und funktioneller Laborparameter bzw. -tests einzuschätzen ist, und welche diagnostischen Methoden in Erprobung sind, wird im vorliegenden Beitrag erläutert.

S100 family proteins in inflammation and beyond

The S100 family proteins possess a variety of intracellular and extracellular functions. They interact with multiple receptors and signal transducers to regulate pathways that govern inflammation, cell differentiation, proliferation, energy metabolism, apoptosis, calcium homeostasis, cell cytoskeleton and microbial resistance. S100 proteins are also emerging as novel diagnostic markers for identifying and monitoring various diseases. Strategies aimed at targeting S100-mediated signaling pathways hold a great potential in developing novel therapeutics for multiple diseases. In this chapter, we aim to summarize the current knowledge about the role of S100 family proteins in health and disease with a major focus on their role in inflammatory conditions.

Fecal calprotectin as a factor that supports the pathogenicity of Dientamoeba fragilis

Calprotectin is a protein that is mostly released from neutrophils, monocytes, macrophages and submucosal epithelial cells. Fecal calprotectin (f-CP) is a marker of intestinal inflammation. There are some discussions about the pathogenicity of D. fragilis in the gastrointestinal tract. In this study, we investigated whether f-CP level is a factor supporting the pathogenicity of D. fragilis. The f-CP levels were evaluated in patients with only D. fragilis positive in comparison with healthy controls. Moreover, the levels of f-CP were investigated in fecal samples of D. fragilis negative patients with gastrointestinal complaints. The fecal samples were collected from three groups. Three groups of fecal samples were examined directly microscopy, trichrome staining, cultivation, enzyme immunoassay (EIA) and real-time PCR assay. In the first group (Group 1, n = 34), patient stool samples with gastrointestinal symptoms (without other pathogens) found only with D. fragilis were included. In the second group (Group 2, n = 31), there were patients' stool samples with gastrointestinal symptoms that D. fragilis was negative (but there may be other pathogenic agents). In the control group (Group 3, n = 23), we used fecal samples collected from healthy volunteers without any infection or gastrointestinal complaints. The collected fecal samples were stored at -20 °C until analysis. Levels of f-CP were determined by using human calprotectin ELISA kits. Total of 88 patients were enrolled in three different groups. We obtained f-CP levels as follows: 33.40 ng/mg protein in the group 1, 15.99 ng/mg protein in the group 2 and 1.54 ng/mg protein in the group 3. Statistically significant difference in f-CP levels of the group 1 and the group 2 were obtained when compared with healthy controls (p < 0.0001). However, the f-CP levels of the group 1 were not significantly different from the group 2 (p > 0.99). In conclusion, increased levels of f-CP are shown as a marker of an inflammatory disease of the lower gastrointestinal tract in infected humans. There is continues controversy about the pathogenicity of D. fragilis in symptomatic and asymptomatic patients. The findings of this study contribute to the ongoing debate about the pathogenicity of D. fragilis. In our study, the potential pathogenicity of D. fragilis is associated with increased f-CP concentrations with parasite detection in the fecal samples and therefore we assume that the parasite is not only a harmless commensal. In summary, higher levels of f-CP found in D. fragilis positive patients suggest the importance of researches that support the pathogenicity of indicated parasite.

Ca2+-Binding Proteins of the EF-Hand Superfamily: Diagnostic and Prognostic Biomarkers and Novel Therapeutic Targets

A multitude of Ca²⁺-sensor proteins containing the specific Ca²⁺-binding motif (helix-loop-helix, called EF-hand) are of major clinical relevance in a many human diseases. Measurements of troponin, the first intracellular Ca-sensor protein to be discovered, is nowadays the "gold standard" in the diagnosis of patients with acute coronary syndrome (ACS). Mutations have been identified in calmodulin and linked to inherited ventricular tachycardia and in patients affected by severe cardiac arrhythmias. Parvalbumin, when introduced into the diseased heart by gene therapy to increase contraction and relaxation speed, is considered to be a novel therapeutic strategy to combat heart failure. S100 proteins, the largest subgroup with the EF-hand protein family, are closely associated with cardiovascular diseases, various types of cancer, inflammation, and autoimmune pathologies. The intention of this review is to summarize the clinical importance of this protein family and their use as biomarkers and potential drug targets, which could help to improve the diagnosis of human diseases and identification of more selective therapeutic interventions.

Noninvasive testing in the management of children with suspected inflammatory bowel disease

Objective: To assess the accuracy of noninvasive parameters, fecal calprotectin (FC), increased bowel wall thickening (BWT) at intestinal ultrasound (IUS) and blood inflammatory indexes (BII), alone or in combination, as diagnostic tools for inflammatory bowel disease (IBD) in pediatric patients. Methods: Retrospective data were collected on consecutive children (age 2-18 years) referred to our pediatric gastroenterology clinic, for recurrent abdominal pain and/or altered bowel habit from 2007 to 2013. Subjects who had diagnostic workup: laboratory tests (FC, BII, white blood cell (WBC), C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR)) and IUS as initial assessment were eligible. Subjects with known gastrointestinal (GI) diseases, or signs or symptoms highly suggestive for organic diseases necessitating prompt endoscopy (e.g., perianal disease or rectal bleeding), or who had recently performed endoscopy were excluded. The accuracy of noninvasive tests for detecting IBD was assessed using endoscopic and/or radiological investigations, performed in subsequent clinical follow up, as reference gold standard. Results: Seventy-seven patients (mean age 11.3, 44 males) were included, 23 (29.9%) with a final diagnosis of IBD. As single tests, FC gave the highest sensitivity (96%) but lower specificity (72%) and IUS highest specificity (96%) with lower sensitivity (70%). The combination of FC + IUS showed excellent accuracy for detecting children with IBD with positive predictive value: 100%; negative predictive value: 88.5%. The probability of IBD in children with normal FC, BII and IUS was 0.09%. Conclusions: FC and increased BWT at IUS are accurate to guide reassurance or proceeding with further invasive procedures for detecting IBD in children with mild GI symptoms.

Consecutive fecal calprotectin measurements for predicting relapse in pediatric Crohn’s disease patients

BACKGROUND

Asymptomatic children with Crohn’s disease (CD) require ongoing monitoring to ensure early recognition of a disease exacerbation.

AIM

In a cohort of pediatric CD patients, we aimed to assess the utility of serial fecal calprotectin measurements to detect intestinal inflammatory activity and predict disease relapse.

METHODS

In this prospective longitudinal cohort study, children with CD on infliximab therapy in clinical remission were included. Fecal calprotectin levels were assessed at baseline and at subsequent 2-5 visits. Clinical and biochemical disease activity were assessed using the Pediatric Crohn’s Disease Activity Index, C-reactive protein and erythrocyte sedimentation rate at baseline and at visits over the following 18 mo.

RESULTS

53 children were included and eighteen patients (34%) had a clinical disease relapse during the study. Baseline fecal calprotectin levels were higher in patients that developed symptomatic relapse [median (interquartile range), relapse 723 μg/g (283-1758) vs 244 μg/g (61-627), P = 0.02]. Fecal calprotectin levels > 250 μg/g demonstrated good predictive accuracy of a clinical flare within 3 mo (area under the receiver operator curve was 0.86, 95% confidence limits 0.781 to 0.937).

CONCLUSION

Routine fecal calprotectin testing in children with CD in clinical remission is useful to predict relapse. Levels > 250 μg/g are a good predictor of relapse in the following 3 mo. This information is important to guide monitoring standards used in this population.

Fecal Calprotectin to Detect Inflammatory Bowel Disease in Juvenile Idiopathic Arthritis

Objective.

This study aimed to test fecal calprotectin (FC) as a screening tool to identify inflammatory bowel disease (IBD) among patients with juvenile idiopathic arthritis (JIA).

Methods.

FC level < 100 g/kg was considered normal. Patients with 2 consecutive FC dosage ≥ 100 g/kg underwent endoscopic evaluation.

Results.

There were 113 patients with JIA enrolled. FC was raised in 7 patients out of 113. All patients had IBD. In 3/7 patients, high FC levels were the only sign consistent with IBD.

Conclusion.

FC is a useful, economical, and noninvasive diagnostic tool to identify JIA patients with underlying IBD.

Autoinhibitory regulation of S100A8/S100A9 alarmin activity locally restricts sterile inflammation

Autoimmune diseases, such as psoriasis and arthritis, show a patchy distribution of inflammation despite systemic dysregulation of adaptive immunity. Thus, additional tissue-derived signals, such as danger-associated molecular patterns (DAMPs), are indispensable for manifestation of local inflammation. S100A8/S100A9 complexes are the most abundant DAMPs in many autoimmune diseases. However, regulatory mechanisms locally restricting DAMP activities are barely understood. We now unravel for the first time, to our knowledge, a mechanism of autoinhibition in mice and humans restricting S100-DAMP activity to local sites of inflammation. Combining protease degradation, pull-down assays, mass spectrometry, and targeted mutations, we identified specific peptide sequences within the second calcium-binding EF-hands triggering TLR4/MD2-dependent inflammation. These binding sites are free when S100A8/S100A9 heterodimers are released at sites of inflammation. Subsequently, S100A8/S100A9 activities are locally restricted by calcium-induced (S100A8/S100A9)2 tetramer formation hiding the TLR4/MD2-binding site within the tetramer interphase, thus preventing undesirable systemic effects. Loss of this autoinhibitory mechanism in vivo results in TNF-α-driven fatal inflammation, as shown by lack of tetramer formation in crossing S100A9-/- mice with 2 independent TNF-α-transgene mouse strains. Since S100A8/S100A9 is the most abundant DAMP in many inflammatory diseases, specifically blocking the TLR4-binding site of active S100 dimers may represent a promising approach for local suppression of inflammatory diseases, avoiding systemic side effects.

Practical guidance on the use of faecal calprotectin

Differentiation between inflammatory bowel disease (IBD) and functional gut disorders, and the determination of mucosal disease activity in established cases of IBD remain the cornerstones of disease diagnosis and management. Non-invasive, accurate biomarkers of gut inflammation are needed due to the variability of symptoms, the inaccuracies of currently available blood markers and the cost and invasive nature of endoscopy. Numerous biomarkers have been used and/or considered with some in current use. This article reviews the current evidence base around the indications for using biomarkers and their limitations, with a particular focus on faecal calprotectin.

Inflammatory bowel disease and patterns of volatile organic compounds in the exhaled breath of children: A case-control study using Ion Molecule Reaction-Mass Spectrometry

Inflammatory bowel diseases (IBD) profoundly affect quality of life and have been gradually increasing in incidence, prevalence and severity in many areas of the world, and in children in particular. Patients with suspected IBD require careful history and clinical examination, while definitive diagnosis relies on endoscopic and histological findings. The aim of the present study was to investigate whether the alveolar air of pediatric patients with IBD presents a specific volatile organic compounds’ (VOCs) pattern when compared to controls. Patients 10–17 years of age, were divided into four groups: Crohn’s disease (CD), ulcerative colitis (UC), controls with gastrointestinal symptomatology, and surgical controls with no evidence of gastrointestinal problems. Alveolar breath was analyzed by ion molecule reaction mass spectrometry. Four models were built starting from 81 molecules plus the age of subjects as independent variables, adopting a penalizing LASSO logistic regression approach: 1) IBDs vs. controls, finally based on 18 VOCs plus age (sensitivity = 95%, specificity = 69%, AUC = 0.925); 2) CD vs. UC, finally based on 13 VOCs plus age (sensitivity = 94%, specificity = 76%, AUC = 0.934); 3) IBDs vs. gastroenterological controls, finally based on 15 VOCs plus age (sensitivity = 94%, specificity = 65%, AUC = 0.918); 4) IBDs vs. controls, built starting from the 21 directly or indirectly calibrated molecules only, and finally based on 12 VOCs plus age (sensitivity = 94%, specificity = 71%, AUC = 0.888). The molecules identified by the models were carefully studied in relation to the concerned outcomes. This study, with the creation of models based on VOCs profiles, precise instrumentation and advanced statistical methods, can contribute to the development of new non–invasive, fast and relatively inexpensive diagnostic tools, with high sensitivity and specificity. It also represents a crucial step towards gaining further insights on the etiology of IBD through the analysis of specific molecules which are the expression of the particular metabolism that characterizes these patients.

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.

Selecting children with suspected inflammatory bowel disease for endoscopy with the calgranulin C or calprotectin stool test: protocol of the CACATU study

INTRODUCTION

The introduction of the faecal calprotectin (FC) test to screen children with chronic gastrointestinal complaints has helped the clinician to decide whether or not to subject the patient to endoscopy. In spite of this, a considerable number of patients without inflammatory bowel disease (IBD) is still scoped. Faecal calgranulin C (S100A12) is a marker of intestinal inflammation that is potentially more specific for IBD than FC, as it is exclusively released by activated granulocytes.

OBJECTIVE

To determine whether the specificity of S100A12 is superior to the specificity of FC without sacrificing sensitivity in patients with suspected IBD.

METHODS

An international prospective cohort of children with suspected IBD will be screened with the existing FC stool test and the new S100A12 stool test. The reference standard (endoscopy with biopsies) will be applied to patients at high risk of IBD, while a secondary reference (clinical follow-up) will be applied to those at low risk of IBD. The differences in specificity and sensitivity between the two markers will be calculated.

ETHICS AND DISSEMINATION

This study is submitted to and approved by the Medical Ethics Review Committee of the University Medical Center Groningen (the Netherlands) and the Antwerp University Hospital (Belgium). The results will be disseminated through a peer-reviewed publication, conference presentation and incorporation in the upcoming National Guideline on Diagnosis and Therapy of IBD in Children.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT02197780 .

Fecal biomarkers in inflammatory bowel disease: how, when and why?

Over the last thirty years knowledge on fecal biomarkers (FM) has substantially increased. Nowadays these non-invasive inflammation markers are used in the daily management of inflammatory bowel disease (IBD). The interest in investigating FM was motivated by the need of a simple, quick, disposable and less invasive marker of disease activity, which might remove the need for endoscopy when following up with patients. Areas covered: Current literature was reviewed for articles regarding the role of FM in IBD diagnosis, activity, flare prediction, medication and surgical treatment response as well as how FM may differ in adult and paediatric IBD patient populations. Expert commentary: Although FM is relevant in IBD patient follow-up, there isn't enough data regarding FM reference values for different ages, different disease subtypes, disease localization/extension or response to therapy. Serial measurements of FM for each patient may be useful in accessing relapse in most patients. FM presented more consistent results when used as a predictive tool of relapse after ileocecal surgery in Crohn's disease. Ongoing research will clarify FM role in decision-making IBD daily practice.

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.

Fecal biomarkers in inflammatory bowel disease

Over the last two decades, knowledge on fecal biomarkers has substantially increased. Nowadays, these non-invasive markers of inflammation have significant clinical utility in the management of inflammatory bowel disease. Their use informs the decision to perform endoscopy before diagnosis is made right through to influencing therapeutic choices and the need for interval endoscopic assessment. In this review, the roles of two S100 proteins, calprotectin, and S100A12 are described along with that of lactoferrin, in the context of inflammatory bowel disease.

Calprotectin Induces IL-6 and MCP-1 Production via Toll-Like Receptor 4 Signaling in Human Gingival Fibroblasts

Calprotectin, a heterodimer of S100A8 and S100A9 molecules, is associated with inflammatory diseases such as inflammatory bowel disease. We have reported that calprotectin levels in gingival crevicular fluids of periodontitis patients are significantly higher than in healthy subjects. However, the functions of calprotectin in pathophysiology of periodontitis are still unknown. The aim of this study is to investigate the effects of calprotectin on the productivity of inflammatory cytokines in human gingival fibroblasts (HGFs). The HGFs cell line CRL-2014® (ATCC) were cultured, and total RNAs were collected to examine the expression of TLR2/4 and RAGE mRNA using RT-PCR. After the cells were treated with S100A8, S100A9, and calprotectin, supernatants were collected and the levels of IL-6 and MCP-1 were measured using ELISA methods. To examine the intracellular signals involved in calprotectin-induced cytokine production, several chemical inhibitors were used. Furthermore, after the siRNA-mediated TLR4 down-regulated cells were treated with S100A8, S100A9, and calprotectin, the levels of IL-6 and MCP-1 were also measured. HGFs showed greater expression of TLR4 mRNA, but not TLR2 and RAGE mRNA compared with human oral epithelial cells. Calprotectin increased significantly the production of MCP-1 and IL-6 in HGFs, and the cytokine productions were significantly suppressed in the cells treated with MAPKs, NF-κB, and TLR4 inhibitors. Furthermore, calprotectin-mediated MCP-1 and IL-6 production were significantly suppressed in TLR4 down-regulated cells. Taken together, calprotectin induces IL-6 and MCP-1 production in HGFs via TLR4 signaling that involves MAPK and NF-κB, resulting in the progression of periodontitis. J. Cell. Physiol. 232: 1862-1871, 2017. © 2016 Wiley Periodicals, Inc.

Comparison of Fecal Calprotectin Methods for Predicting Relapse of Pediatric Inflammatory Bowel Disease

Background. Pediatric inflammatory bowel disease (IBD) is on the rise worldwide. Endoscopies are necessary for IBD assessment but are invasive, expensive, and inconvenient. Recently, fecal calprotectin (FCal) was proposed as a noninvasive and specific marker of gut inflammation. We evaluated the analytical performance of three FCal assays and their clinical performance in predicting relapse in pediatric IBD. Methods. This study used 40 pediatric IBD and 40 random non-IBD patients' fecal samples. Two automated ELISAs (Bühlmann and PhiCal® Calprotectin-EIA) and an EliA (Phadia 250 EliA-Calprotectin) were used to evaluate the analytical performance. The clinical performance was assessed by PhiCal Calprotectin-EIA, EliA-Calprotectin, and Bühlmann immunochromatographic point-of-care test (POCT). Results. All assays displayed acceptable analytical performance below and above the medical decision cut-off [imprecision (CV < 10% intra-assay; <15% interassay); linearity (overall mean % deviation < 16.5%)]. The agreement with PhiCal Calprotectin-EIA was 100% and 78.6% for Bühlmann (95% CI, 87.5-100; Kappa: 1) and EliA-Calprotectin (95% CI, 60.5-89.8; Kappa: 0.32), respectively, and 63.6% between Bühlmann and EliA-Calprotectin (95% CI, 46.6-77.8; Kappa: 0.16). All assays evaluated had similar clinical performance [AUC: 0.84 (EliA-Calprotectin); 0.83 (POCT and PhiCal Calprotectin-EIA)]. Conclusion. FCal levels determined using the same method and assay together with clinical history would be a noninvasive and useful tool in monitoring pediatric IBD.

Fecal Calprotectin in Healthy Children Aged 1-4 Years

Objective

Calprotectin has been well emulated recently in adults as well as in children. The aim of this study was to assess fecal calprotectin concentrations in healthy children aged from 1 to 4 years.

Methods

Volunteers were enlisted from 3 nurseries. A brief questionnaire was used to ensure these children meet the inclusion criteria, and some clinical and sociodemographic factors were collected. Anthro software (version 3.1) was used to calculated Length-for-age Z-scores (LAZ), weight-for-age Z-scores (WAZ), and weight-for-length Z-scores (WLZ) respectively. Fecal calprotectin was detected by a commercially available ELISA.

Results

In total 274 children were recruited, with age ranging from 1 to 4 years old. The median FC concentration was 83.19 μg/g [range 4.58 to 702.50 μg/g, interquartile range (IQR) 14.69–419.45 μg/g] or 1.92 log10 μg/g (range 0.66 log10 to 2.85 log10 μg/g, IQR 1.17 log10-2.62 log10 μg/g). All of the children were divided into three groups, 1–2 years (12–24 months), 2–3 years (24–36 months), 3–4 years (36–48 months), with median FC concentrations 96.14 μg/g (1.98 log10 μg/g), 81.48 μg/g (1.91 log10 μg/g), 65.36 μg/g (1.82 log10 μg/g), respectively. There was similar FC level between boys and girls. FC concentrations showed a downward trend by the growing age groups. A statistic difference was found in FC concentrations among groups 1–2 years, 2–3 years and 3–4 years (P = 0.016). In inter-groups comparison, a significant difference was found between children aged 1–2 years and children aged 3–4 years (P = 0.007). A negative correlation trend was found between age and FC concentration (Spearman's rho = -0.167, P = 0.005) in all the participants. A simple correlation was performed among WLZ, WAZ, birth weight, or birth length with FC, and there was no correlation being observed.

Conclusion

Children aged from 1 to 4 years old have lower FC concentrations compared with healthy infants (<1years), and higher FC concentrations when comparing with children older than 4 years and adults.

Intestinal permeability in children with recurrent respiratory and gastrointestinal symptoms

AIM

Increased intestinal permeability has been reported in asthmatic subjects as well as in patients with gastrointestinal disease, thus suggesting the involvement of all the mucosal immune system. We aimed to assess intestinal permeability according to recurrent respiratory and gastrointestinal symptoms in children with asthma and children with functional gastrointestinal disorders (FGIDs).

METHODS

In 108 outpatients aged 3-14 years (45 asthmatic, 63 with FGIDs), we measured the urinary lactulose/mannitol (L/M) ratio, performed allergy skin prick tests and administered questionnaires for recurrent respiratory and gastrointestinal symptoms starting from at least 2 months which persisted over the previous 4 weeks. L/M ratios were compared with previously reported normal values yielded by our chromatographic method (liquid chromatography-mass spectrometry).

RESULTS

High L/M ratios (>0.030) were less frequent in asthmatic children than in children with FGIDs (9/45: 20% vs. 41/63: 65%, P < 0.001). High L/M ratios were associated with gastrointestinal symptoms in 8/9 asthmatic (P < 0.05) and 39/41 subjects with FGIDs (P < 0.005). L/M ratios were not associated with respiratory symptoms or atopy. In a regression model, a high L/M was predicted by low height, absence of asthma and presence of gastrointestinal symptoms (r = 0.72, P < 0.001).

CONCLUSIONS

Increased intestinal permeability is associated with recurrent gastrointestinal symptoms rather than with recurrent respiratory symptoms in both asthmatic children and those with FGIDs. Our findings do not support the hypothesis of mucosal intestinal damage following an inflammatory stimulus in the respiratory mucosa.

Disease monitoring in inflammatory bowel disease

The optimal method for monitoring quiescent disease in patients with Crohn’s disease (CD) and ulcerative colitis is yet to be determined. Endoscopic evaluation with ileocolonoscopy is the gold standard but is invasive, costly, and time-consuming. There are many commercially available biomarkers that may be used in clinical practice to evaluate disease status in patients with inflammatory bowel disease (IBD), but the most widely adopted biomarkers are C-reactive protein (CRP) and fecal calprotectin (FC). This review summarizes the evidence for utilizing CRP and FC for monitoring IBD during clinical remission and after surgical resection. Endoscopic correlation with CRP and FC is evaluated in each disease state. Advantages and drawbacks of each biomarker are discussed with special consideration of isolated ileal CD. Fecal immunochemical testing, traditionally used for colorectal cancer screening, is mentioned as a potential new alternative assay in the evaluation of IBD. Based on a mixture of information gleaned from biomarkers, clinical status, and endoscopic evaluation, the best treatment decisions can be made for the patient with IBD.

Is faecal calprotectin equally useful in all Crohn's disease locations? A prospective, comparative study

INTRODUCTION

There are data suggesting that the diagnostic usefulness of faecal calprotectin (FC) may vary depending on the Crohn's disease (CD) location. The aim of the study was to compare the diagnostic usefulness of FC in CD patients with different disease locations.

MATERIAL AND METHODS

We prospectively enrolled 120 CD patients in the study. Disease activity was assessed by using Crohn's Disease Activity Index (CDAI), biochemical markers, and endoscopic and radiographic methods. Faecal calprotectin concentration was assessed in single stool samples by using the ELISA method.

RESULTS

Among all patients, 54 (45%) had ileocolonic CD location, 44 (36.5%) had isolated small bowel location, and 22 (18.5%) had colonic CD location. FC correlated significantly with C-reactive protein concentration and endoscopic and radiographic activity among patients with isolated small bowel CD (p = 0.03, r = 0.32; p < 0.0001, r = 0.78; p = 0.03, r = 0.35; respectively) and with C-reactive protein and endoscopic activity in isolated colonic CD (p = 0.0009, r = 0.7; p = 0.0002, r = 0.78; respectively). CDAI and inflammatory biochemical markers did not correlate with endoscopic and radiographic assessment in small bowel CD. In patients with ileocolonic CD, FC correlated significantly with endoscopy (p = 0.006, r = 0.5), radiographic assessment (p = 0.04, r = 0.3), CDAI (p = 0.0006, r = 0.5) and the majority of biochemical markers.

CONCLUSIONS

Faecal calprotectin is a useful diagnostic marker in all CD patients. Although its usefulness in small bowel CD seems to be the lowest, it should be utilized particularly in this disease location because of the lack of other reliable, non-invasive diagnostic methods.

Faecal calprotectin levels in children with Henoch-Schönlein purpura: is this a new marker for gastrointestinal involvement?

AIM

We aimed to investigate the significance of faecal calprotectin (FC) levels in children diagnosed with Henoch-Schönlein purpura (HSP) and examine its relationships with gastrointestinal system (GIS), renal involvement and with clinical findings.

PATIENTS AND METHODS

In total, 66 children diagnosed with HSP for the first time and a control group of 25 healthy children were included. The cases were divided into mild and severe groups on the basis of GIS findings. FC was measured twice in all patients with HSP: within 3 days of onset of disease (FC1) and on day 15 (FC2). These results were compared with those of the control group. Faecal occult blood, gastric wall thickness and duodenal wall thickness were measured at the same time as FC1 in all patients, and the presence of renal involvement was recorded.

RESULTS

Of the 66 patients, 37 (56%) were females (mean age, 7.5±2.9 years; range, 2.5-14.5 years) and were diagnosed with HSP. Renal involvement was detected in 19 (28%) cases and GIS involvement was found in 28 (43%) cases. GIS involvement was mild in 16 (53%) cases and severe in 12 (43%). A significant difference was detected in FC1 levels between the groups with and without GIS involvement (P=0.01). A marked difference was observed in FC1 levels between the groups with and without renal involvement (P=0.017).

CONCLUSION

FC may be a reliable marker for HSP, particularly for identifying GIS and renal involvement as well as disease severity.

Fecal calprotectin in diagnosis and clinical assessment of inflammatory bowel disease

The fecal neutrophil-derived biomarker calprotectin has several features of an ideal noninvasive test for detecting intestinal inflammation: it is simple, reliable, and low in cost. Its utility in differentiating inflammatory bowel diseases (IBDs) from functional conditions such as irritable bowel syndrome is well documented. Fecal calprotectin (FC) correlates closely with endoscopic activity of IBD. Emerging evidence suggest its usefulness in serial monitoring of disease activity and of therapy success in IBD. A low FC concentration predicts persistence of clinical remission especially in non-symptomatic ulcerative colitis and Crohn's colitis. Here, an overview is given to the current role of FC in diagnosis and clinical assessment of IBD.

Proteolysis is a confounding factor in the interpretation of faecal calprotectin

Calprotectin is a 36 kDa calcium and zinc binding protein. An increased level of calprotectin points towards inflammatory bowel disease. However, the biomarker calprotectin shows 14 potential cleavages sites for trypsin. Next to trypsin, also the presence of its inhibitor α

An in vitro model was created. As calprotectin source, leukocytes were isolated and subsequently lysed (1% Triton X-100) and diluted in faecal matrix. Trypsin digestion was carried out by adding trypsin. Incubation occurred for 24 h or 48 h (37 °C). To study the influence of α

In vitro experiments enabled monitoring of the faecal calprotectin digestion, leading to loss of immunoreactivity. Trypsin activity was a potential confounder in the interpretation of calprotectin, in particular for proximal lesions, where exposure of calprotectin to trypsin is prolonged. Relative calprotectin loss was proportional to the amount of trypsin. Decrease of calprotectin was more pronounced after 48 h of incubation in comparison to 24 h of incubation. Analogue experiments also showed stable calprotectin values after adding α

Transit time, trypsin activity and addition of blood as a source of α

Clinical utility of fecal neutrophil-derived biomarkers in evaluating activity of inflammatory bowel disease

Inflammatory bowel disease (IBD) is a group of chronic, idiopathic intestinal diseases characterized by periods of remission and relapses. Evaluating the activity of IBD timely and accurately is crucial to guide treatment. The change of neutrophils in the intestinal tissue is correlated closely with the activity of IBD. This article reviews the clinical utility of fecal neutrophil-derived biomarkers in assessing the activity of IBD.

Looking for new treatments of Infantile Colic

Infantile colic is a common disturbance occurring in the first three months of life. It is a benign condition and one of the main causes of pediatric consultation in the early part of life because of its great impact on family life. Some pediatricians are prone to undervalue this issue mainly because of the lack of evidence based medicine guidelines. Up to now, there is no consensus concerning management and treatment. Literature reports growing evidence about the effectiveness of dietary, pharmacological, complementary and behavioral therapies as options for the management of infantile colic. Dietary approach, usually based on the avoidance of cow's milk proteins in breast-feeding mothers and bottle-fed infants, more recently has seen the rise of new special formulas, such as partially hydrolyzed proteins and low lactose added with prebiotics or probiotics: their efficacy needs to be further documented. Investigated pharmacological agents are Simethicone and Cimetropium Bromide: the first is able to reduce bloating while the second could reduce fussing crying, but it has been tested only for severe infantile colic. No other pain relieving agents have been proposed until now, but some clinical trials are ongoing for new drugs.There is limited evidence supporting the use of complementary and alternative treatments (herbal supplements, manipulative approach and acupuncture) or behavioral interventions.Recent studies have focused the role of microbiota in the pathogenesis of this disturb and so new treatments, such as probiotics, have been proposed, but only few strains have been tested.Further investigations are needed in order to provide evidence-based guidelines.

Comparison of three tests for faecal calprotectin in children and young adults: a retrospective monocentric study

OBJECTIVE

Faecal calprotectin is used as a sensitive marker for gastrointestinal mucosal inflammation. We compared the performance of three different assays in a large cohort of symptomatic paediatric patients.

DESIGN

Retrospective monocentric study.

SETTING

Inpatients and outpatients of a tertiary referral centre for paediatric gastroenterology.

PARTICIPANTS

304 symptomatic patients (163 males, aged 2-20 years) with active inflammatory bowel disease (IBD/A, n=130), IBD in clinical remission (IBD/R, n=62), other intestinal diseases (n=45) and controls without identified intestinal disease (n=67).

INTERVENTIONS

Calprotectin was measured in homogenised faecal samples with three tests (A: EliA Calprotectin, Phadia AB, Sweden; B: PhiCal, Calpro AS, Norway; C: EK-Cal, Bühlmann Laboratories, Switzerland).

OUTCOMES

Concordance between tests was calculated using Kendall's τ coefficient.

RESULTS

IBD/A and controls were correctly classified as 97.7%/82.1% (A), 97.7%/85.1% (B) and 98.4%/62.7% (C; not significant). Test C tended to have higher calprotectin values with a lower specificity compared to tests A and B. The concordance between two tests was 0.835 for tests A and B, 0.782 for tests A and C and 0.765 for tests B and C.

CONCLUSIONS

All three tests are very sensitive for detecting mucosal inflammation, but major differences exist between specificity and absolute values. It is highly advisable to use the test of the same manufacturer for follow-up and to monitor for disease activity.

Fecal calprotectin in healthy children

Calprotectin is a protein found in the cytosol of inflammatory cells and is a marker of the presence and the degree of inflammation in the bowel system. Calprotectin in feces has great diagnostic value in the matter of inflammatory bowel disease (IBD). In feces, the protein is stable up to seven days, and since the protein can easily be measured with an ELISA, the use of fecal calprotectin (FC) means no invasive measures. For adults and children over 4 years, a cut-off level of 50 mg/kg has been well established for diagnostic purposes. Because previous studies have proven that children under the age of four in general have higher FC values than older children and adults, there is a need for a cut-off level for this age group. In order to establish that, the normal values for FC in children from 0-4 years were investigated. Some 75 stool samples from healthy children were collected and the levels of FC were analyzed. The results were compared to 157 pediatric cases where FC analysis had been performed for diagnostic purposes. As a result, three cut-off levels were established based on the 97.5% percentiles of FC in different age groups: 538 mg/kg (1 < 6 months), 214 mg/kg (6 months < 3 years) and 75 mg/kg (3 < 4 years).

Diagnostics and prognostics of inflammatory bowel disease with fecal neutrophil-derived biomarkers calprotectin and lactoferrin

Crohn's disease (CD), ulcerative colitis (UC), and colitis unclassified, collectively defined as inflammatory bowel disease (IBD), are the consequence of chronic inflammatory reactions in the gastrointestinal tissue. Endoscopy with biopsies is the mainstay in the diagnosis of this inflammation and is also important in the assessment of disease activity and monitoring of treatment. Furthermore, mucosal healing is increasingly becoming a therapeutic target for treatment of IBD and the golden standard of assessing it is endoscopy. However, due to the costs, invasiveness, and to limited endoscopic capacity, the need is strong for reliable surrogate markers of intestinal inflammation. Bowel contents, being in close contact with intestinal mucosa, can take up molecules that are measurable from stool samples and thus can serve as markers of inflammation. The fecal neutrophil-derived biomarkers, especially calprotectin and lactoferrin, have several features of an ideal test for detecting intestinal inflammation: they are noninvasive, simple, and low in cost. The utility of these biomarkers in distinguishing IBD from noninflammatory conditions such as irritable bowel syndrome is well documented. They correlate closely with endoscopic activity both in CD and UC. They allow serial monitoring of disease activity and of treatment success, and can even serve in predicting clinical relapse in unsymptomatic patients or sustained remission after induction with TNF-α-blocking agents. In this review an overview will be given to the role of fecal neutrophil-derived biomarkers calprotectin and lactoferrin in diagnostics and prognostics of IBD.

The role of calprotectin in pediatric disease

Calprotectin (CP) is a calcium- and zinc-binding protein of the S100 family expressed mainly by neutrophils with important extracellular activity. The aim of the current review is to summarize the latest findings concerning the role of CP in a diverse range of inflammatory and noninflammatory conditions among children. Increasing evidence suggests the implication of CP in the diagnosis, followup, assessment of relapses, and response to treatment in pediatric pathological conditions, such as inflammatory bowel disease, necrotizing enterocolitis, celiac disease, intestinal cystic fibrosis, acute appendicitis, juvenile idiopathic arthritis, Kawasaki disease, polymyositis-dermatomyositis, glomerulonephritis, IgA nephropathy, malaria, HIV infection, hyperzincemia and hypercalprotectinemia, and cancer. Further studies are required to provide insights into the actual role of CP in these pathological processes in pediatrics.

Update in pediatric inflammatory bowel disease

The incidence of inflammatory bowel disease (IBD), Crohn's disease and ulcerative colitis, in children is on the rise. Pediatric patients with IBD are especially vulnerable to the physical and psychosocial morbidities of this disorder. Unique aspects of pediatric IBD patients compared to adult patients warrants an individualized approach to management regardless of age. This review focuses on the special aspects of pediatric IBD and the implications for the diagnosis and management of this disease.