Use of Laboratory Markers in Addition to Symptoms for Diagnosis of Inflammatory Bowel Disease in Children: A Meta-analysis of Individual Patient Data

Multicenter registry of pediatric inflammatory bowel disease from a developing country

BACKGROUND

Despite the rising incidence of pediatric inflammatory bowel disease (PIBD) globally, multicenter collaborative studies of PIBD children among developing countries remain sparse. We therefore aimed to define the initial presentation and short-term outcomes of Thai children with PIBD from a multicenter registry.

METHODS

Four teaching hospitals participated in this study. A diagnosis of PIBD requires gastrointestinal endoscopy and histopathology in children aged < 19 years. Besides demographics, we collected clinical information and treatment with the data at 1-year follow up.

RESULTS

We included 35 Crohn's disease (CD), one IBD-unclassified, and 36 ulcerative colitis (UC) children (total n = 72 with 60.6% males). The mean age at diagnosis was 7.9 years (SD 4.1) with 38% being very early onset IBD (VEO-IBD). When compared with UC, the CD children were more likely to exhibit fever (42.3 vs. 13.9%), weight loss/failure to thrive (68.6 vs. 33.3%), and hypoalbuminemia (62.9 vs. 36.1%) but less likely to have bloody stools (51.4 vs. 91.7%) (all P < 0.05). No significant differences in demographics, clinical data and medications used with regards to VEO-IBD status. At 1 year after diagnosis (n = 62), 30.7% failed to enter clinical remission and 43.7% remained on systemic corticosteroids. Diarrhea (OR 9.32) and weight issues (OR 4.92) at presentation were independent predictors of failure to enter clinical remission; and females (OR 3.08) and CD (vs. UC) (OR 3.03) were predictors of corticosteroids use at 1-year follow-up.

CONCLUSIONS

A high proportion of VEOIBD is noted, and CD was more likely to present with significant inflammatory burden. Diarrhea and weight issues at presentation were independent predictors of failure to enter clinical remission; and females and CD (vs. UC) were predictors of corticosteroids use at 1-year follow-up.

Management of children with non-acute abdominal pain and diarrhea in Dutch primary care: a retrospective cohort study based on a routine primary care database (AHON)

OBJECTIVE

To describe the testing, prescription, referral, and follow-up management by general practitioners (GPs) for children presenting with non-acute abdominal pain and/or diarrhea in primary care.

DESIGN

Retrospective cohort study with one-year follow-up.

SETTING

Registry data from a Dutch primary care database (AHON) between 2015 and 2019.

SUBJECTS

Children aged 4-18 years old who presented by face-to-face consultation in primary care for non-acute abdominal pain and/or diarrhea (>7 days).

MAIN OUTCOME MEASURES

We recorded the proportions of children who received (1) diagnostic testing, medicine prescriptions, follow-up consultations, and referrals at their first visit and (2) repeat consultations and referrals by one-year of follow-up.

RESULTS

Among the 2200 children (median age, 10.5 years; interquartile range, 7.0-14.6) presenting to a GP with non-acute abdominal pain and/or diarrhea, most reported abdominal pain (78.7%). At the first visit, GPs performed diagnostic testing for 32.2%, provided a prescription to 34.5%, and referred 2.5% to secondary care. Twenty-five percent of the children had a follow-up consultation within four weeks and 20.8% had a repeat consultation between four weeks and one year. Thirteen percent of the children were referred to secondary care by one year. However, only 1% of all children had documentation of an organic diagnosis needing management in secondary care.

CONCLUSION

One-third of children received diagnostic testing or a medicine prescription. Few had a follow-up consultation and >10% was referred to pediatric care. Future research should explore the motivations of GPs why and which children receive diagnostic and medical interventions.

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.

Identification of FCN1 as a novel macrophage infiltration-associated biomarker for diagnosis of pediatric inflammatory bowel diseases

BACKGROUND

The incidence of pediatric inflammatory bowel disease (PIBD) has been steadily increasing globally. Delayed diagnosis of PIBD increases the risk of complications and contributes to growth retardation. To improve long-term outcomes, there is a pressing need to identify novel markers for early diagnosis of PIBD.

METHODS

The candidate biomarkers for PIBD were identified from the GSE117993 dataset by two machine learning algorithms, namely LASSO and mSVM-RFE, and externally validated in the GSE126124 dataset and our PIBD cohort. The role of ficolin-1 (FCN1) in PIBD and its association with macrophage infiltration was investigated using the CIBERSORT method and enrichment analysis of the single-cell dataset GSE121380, and further validated using immunoblotting, qRT-PCR, and immunostaining in colon biopsies from PIBD patients, a juvenile murine DSS-induced colitis model, and THP-1-derived macrophages.

RESULTS

FCN1 showed great diagnostic performance for PIBD in an independent clinical cohort with the AUC of 0.986. FCN1 expression was upregulated in both colorectal biopsies and blood samples from PIBD patients. Functionally, FCN1 was associated with immune-related processes in the colonic mucosa of PIBD patients, and correlated with increased proinflammatory M1 macrophage infiltration. Furthermore, single-cell transcriptome analysis and immunostaining revealed that FCN1 was almost exclusively expressed in macrophages infiltrating the colonic mucosa of PIBD patients, and these FCN1⁺ macrophages were related to hyper-inflammation. Notably, proinflammatory M1 macrophages derived from THP-1 expressed high levels of FCN1 and IL-1β, and FCN1 overexpression in THP-1-derived macrophages strongly promoted LPS-induced activation of the proinflammatory cytokine IL-1β via the NLRP3-caspase-1 axis.

CONCLUSIONS

FCN1 is a novel and promising diagnostic biomarker for PIBD. FCN1⁺ macrophages enriched in the colonic mucosa of PIBD exhibit proinflammatory phenotypes, and FCN1 promotes IL-1β maturation in macrophages via the NLRP3-caspase-1 axis.

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.

Diagnostic Utility of Non-invasive Tests for Inflammatory Bowel Disease: An Umbrella Review

Background

This study aims to consolidate evidence from published systematic reviews and meta-analyses evaluating the diagnostic performances of non-invasive tests for inflammatory bowel disease (IBD) in various clinical conditions and age groups.

Methods

Two independent reviewers systematically identified and appraised systematic reviews and meta-analyses assessing the diagnostic utility of non-invasive tests for IBD. Each association was categorized as adults, children, and mixed population, based on the age ranges of patients included in the primary studies. We classified clinical scenarios into diagnosis, activity assessment, and predicting recurrence.

Results

In total, 106 assessments from 43 reviews were included, with 17 non-invasive tests. Fecal calprotectin (FC) and fecal lactoferrin (FL) were the most sensitive for distinguishing IBD from non-IBD. However, anti-neutrophil cytoplasmic antibodies (ANCA) and FL were the most specific for it. FC and FL were the most sensitive and specific tests, respectively, to distinguish IBD from irritable bowel syndrome (IBS). Anti-Saccharomyces cerevisiae antibodies (ASCA), IgA, were the best test to distinguish Crohn’s disease (CD) from ulcerative colitis (UC). Interferon-γ release assay was the best test to distinguish CD from intestinal tuberculosis (ITB). Ultrasound (US) and magnetic resonance enterography (MRE) were both sensitive and specific for disease activity, along with the high sensitivity of FC. Small intestine contrast ultrasonography (SICUS) had the highest sensitivity, and FC had the highest specificity for operative CD recurrence.

Conclusion

In this umbrella review, we summarized the diagnostic performance of non-invasive tests for IBD in various clinical conditions and age groups. Clinicians can use the suggested non-invasive test depending on the appropriate clinical situation in IBD patients.

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.

Current status of fecal calprotectin as a diagnostic or monitoring biomarker for cow's milk protein allergy in children: a scoping review

BACKGROUND

There are few approved biomarkers for diagnosis and monitoring of cow's milk protein allergy (CMPA), thus the oral food challenge remains to be the golden diagnostic standard. A potential biomarker is fecal calprotectin, a cytosolic protein, elevating in the presence of intestinal mucosal inflammation. We aimed to undertake a scoping review of the evidence pertaining to the current status of fecal calprotectin used for diagnosis and monitoring CMPA in children, and tried to indicate the aspects needed to be concerned in the future investigations and researches.

METHODS

A scoping review was performed using the literature searched from PUBMED, EMBASE, and Web of Science Databases until July 2019 on the studies about the application of fecal calprotectin as a biomarker of CMPA in children. Studies were examined according to the inclusion and exclusion criteria. Data were extracted, and a narrative synthesis was conducted to summarize and analyze.

RESULTS

Thirteen studies with different study design embracing 1238 children were included. The age range was from infants to adolescents. Most children with CMPA presented gastrointestinal symptoms, among which hematochezia was most common. Amount of data suggested that infants with CMPA represented elevated levels of fecal calprotectin, particularly with distinct significance in non-IgE-mediated CMPA groups. Decreases of fecal calprotectin after elimination diet were demonstrated in enrolled studies. However, no matter in the CMPA positive or negative groups, the changes of fecal calprotectin before or after challenge showed no significance. Contradictory results were generated from studies on the role of fecal calprotectin in predicting allergic disease.

CONCLUSIONS

Available evidence is not sufficient to confirm the utilization of fecal calprotectin both in diagnosis and monitoring of CMPA and predicting for allergic disease. More clinical and bench researches with elaborate design should be conducted and the exact cut-off values of fecal calprotectin in different groups remain to be determined.

Analysis of Using the Total White Blood Cell Count to Define Severe New-onset Ulcerative Colitis in Children

OBJECTIVES

The aim of this study was to assess common laboratory tests in identifying severe ulcerative colitis in children at diagnosis.

METHODS

A cohort of 427 children 4 to 17 years of age newly diagnosed with ulcerative colitis (UC) was prospectively enrolled. Boosted classification trees were used to characterize predictive ability of disease attributes based on clinical disease severity using Pediatric Ulcerative Colitis Activity Index (PUCAI), severe (65+) versus not severe (<65) and total Mayo score, severe (10-12) versus not severe (<10); mucosal disease by Mayo endoscopic subscore, severe (3) versus not severe (<3); and extensive disease versus not extensive (left-sided and proctosigmoiditis).

RESULTS

Mean age was 12.7 years; 49.6% (n = 212) were girls, and 83% (n = 351) were Caucasian. Severe total Mayo score was present in 28% (n = 120), mean PUCAI score was 49.8 ± 20.1, and 33% (n = 142) had severe mucosal disease with extensive involvement in 82% (n = 353). Classification and regression trees identified white blood cell count, erythrocyte sedimentation rate, and platelet count (PLT) as the set of 3 best blood laboratory tests to predict disease extent and severity. For mucosal severity, albumin (Alb) replaced PLT. Classification models for PUCAI and total Mayo provided sensitivity of at least 0.65 using standard clinical cut-points with misclassification rates of approximately 30%.

CONCLUSIONS

A combination of the white blood cell count, erythrocyte sedimentation rate, and either PLT or albumin is the best predictive subset of standard laboratory tests to identify severe from nonsevere clinical or mucosal disease at diagnosis in relation to objective clinical scores.

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.

[Role of NLRP1 and NLRP3 inflammasome signaling pathways in the immune mechanism of inflammatory bowel disease in children]

OBJECTIVE

To study the role of nucleotide-binding oligomerization domain-like receptor proteins 1 and 3 (NLRP1 and NLRP3) inflammasome signaling pathways in the immune mechanism of inflammatory bowel disease (IBD) in children.

METHODS

A total of 126 children with IBD were enrolled as the study group, including 32 children with Crohn's disease (CD) and 94 children with ulcerative colitis (UC). A total of 120 children who underwent colectomy were enrolled as the control group. The mRNA expression of NLRP1, NLRP3, Caspase-1, and interleukin-1β (IL-1β) was compared between groups.

RESULTS

The study group had significantly higher mRNA expression of NLRP1, NLRP3, Caspase-1, and IL-1β than the control group, and their mRNA expression levels tended to increase with the severity of CD or UC (P<0.05). In the children with UC or CD, the mRNA expression levels of NLRP1, NLRP3, Caspase-1, and IL-1β were positively correlated with serum IgM and IgG levels (P<0.05), and the mRNA expression levels of NLRP1 and NLRP3 were positively correlated with those of Caspase-1 and IL-1β (P<0.05).

CONCLUSIONS

The NLRP1 and NLRP3 inflammasome signaling pathways may regulate the immune mechanism of IBD in children by upregulating the expression of Caspase-1 and IL-1β.

Are calprotectin and lactoferrin equivalent screening tests for inflammatory bowel disease?

BACKGROUND

Lactoferrin and calprotectin are frequently ordered stool tests used to screen patients for inflammatory bowel disease versus functional bowel disease. Current guidelines recommend using either one to screen for inflammation in the GI tract; however, little information is available on how these 2 assays compare and their use in different clinical specialties.

METHODS

We compared order patterns for lactoferrin and calprotectin using data from a large reference laboratory over a 10-y period (2009-2019). We also studied the concordance of lactoferrin and calprotectin in cases where both tests were ordered concurrently. Finally, we reviewed the records at a university hospital to determine which clinicians ordered each test and the indications associated with orders.

RESULTS

Orders for calprotectin are increasing relative to lactoferrin. The relative proportion of calprotectin orders have increased from 60% to nearly 90% over the past decade. Results for lactoferrin and calprotectin show concordance (90%). Calprotectin and lactoferrin are ordered by different clinical specialties for different indications. Calprotectin is most often ordered by gastroenterologists in the context of abdominal pain. Lactoferrin is most often ordered by primary care providers in the context of acute diarrhea.

CONCLUSION

Lactoferrin and calprotectin are not treated as equivalent tests by clinicians.

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.

Fecal Calprotectin in Combination With Standard Blood Tests in the Diagnosis of Inflammatory Bowel Disease in Children

Introduction: Fecal calprotectin (FC) is a useful non-invasive screening test but elevated levels are not specific to inflammatory bowel disease (IBD). The study aimed to evaluate the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of FC alone or FC in combination with other standard blood tests in the diagnosis of IBD. Methods: Children aged <17 years who had FC (normal range <50 μg/g) measured and underwent endoscopy over 33 months in Christchurch, New Zealand were identified retrospectively (consecutive sampling). Medical records were reviewed for patient final diagnoses. Results: One hundred and two children were included; mean age was 12.3 years and 53 were male. Fifty-eight (57%) of the 102 children were diagnosed with IBD: 49 with Crohn's disease, eight with ulcerative colitis and one with IBD-unclassified. FC of 50 μg/g threshold provided a sensitivity of 96.6% [95% confident interval (CI) 88.3-99.4%] and PPV of 72.7% (95% CI 61.9-81.4%) in diagnosing IBD. Two children with IBD however were found to have FC <50 μg/g. Sensitivity in diagnosing IBD was further improved to 98.3% (95% CI 90.7-99.1%) when including FC >50 μg/g or elevated platelet count. Furthermore, PPVs in diagnosing IBD improved when FC at various thresholds was combined with either low albumin or high platelet count. Conclusion: Although FC alone is a useful screening test for IBD, a normal FC alone does not exclude IBD. Extending FC to include albumin or platelet count may improve sensitivity, specificity, PPV and NPV in diagnosing IBD. However, prospective studies are required to validate this conclusion.

Utility of Diagnostic Tests in Children With Functional Abdominal Pain Disorders

Functional gastrointestinal disorders (FGIDs) and functional abdominal pain disorders (FAPDs) are common in pediatric patients. The prevalence of FGIDs using the Rome IV criteria ranges from 21.1% to 25.0% in children. The Rome IV criteria specify that the decision of testing is left to the clinician, giving him or her freedom to decide on the necessary workup. The clinician should consider all of the functional and organic diseases that manifest with chronic abdominal pain, as well as alarm features that should prompt testing. Societal guidelines and reports do not recommend routine evaluations for FAPDs, particularly in the absence of alarm features. Studies have reported variable results upon assessing the diagnostic yields of different tests. Furthermore, these evaluations considerably increase costs for the health care system. This article examines the current evidence on the utility of diagnostic testing in pediatric patients with FAPDs.

Normal fecal calprotectin levels in healthy children are higher than in adults and decrease with age

Background/Objectives

The paediatric reference range of fecal calprotectin (FC) has not been decisively established and previous studies show a wide within-age variability, suggesting that other factors like anthropometric data or type of feeding can influence FC. Our aims were to establish the normal levels of FC in healthy children grouped by age and analyze whether sex, gestational age, birth weight, type of delivery, type of feeding, or anthropometric data influence FC values.

Methods

This multicentre, cross-sectional, and observational study enrolled healthy donors under 18 years of age who attended their Primary Health Care Centre for their routine Healthy Child Program visits. The exclusion criteria were: (i) immunodeficiency, (ii) autoimmune or (iii) gastrointestinal disease; (iv) medication usage; (v) gastrointestinal symptoms; or (vi) positive finding in the microbiological study.

Results

We enrolled 395 subjects, mean age was 4.2 years (range 3 days to 16.9 years), and 204 were male. The median FC was 77.0 mcg/g (interquartile range 246). A negative correlation between age and FC was observed (Spearman's rho = -0.603, P<0.01), and none of the other factors analyzed were found to influence FC levels.

Conclusions

Normal FC values in healthy children (particularly in infants) are higher than those considered to be altered in adults and show a negative correlation with age. It is necessary to reconsider the upper limits of FC levels for paediatric patients according to age, with further studies required to determine other factors that influence FC during infancy.

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.

ACG Clinical Guideline: Ulcerative Colitis in Adults

Ulcerative colitis (UC) is an idiopathic inflammatory disorder. These guidelines indicate the preferred approach to the management of adults with UC and represent the official practice recommendations of the American College of Gastroenterology. The scientific evidence for these guidelines was evaluated using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) process. In instances where the evidence was not appropriate for GRADE, but there was consensus of significant clinical merit, "key concept" statements were developed using expert consensus. These guidelines are meant to be broadly applicable and should be viewed as the preferred, but not only, approach to clinical scenarios.

Endoscopy in Pediatric Inflammatory Bowel Disease: A Position Paper on Behalf of the Porto IBD Group of the European Society for Pediatric Gastroenterology, Hepatology and Nutrition

Endoscopy is a central tool for the evaluation and management of inflammatory bowel disease (IBD). In the last few decades, gastrointestinal (GI) endoscopy has undergone significant technological developments including availability of pediatric-size equipment, enabling comprehensive investigation of the GI tract in children. Simultaneously, professional organization of GI experts have developed guidelines and training programs in pediatric GI endoscopy. This prompted the Porto Group on Pediatric IBD of the European Society for Pediatric Gastroenterology, Hepatology and Nutrition to develop updated guidelines on the role of GI endoscopy in pediatric IBD, specifically taking into considerations of recent advances in the diagnosis, disease stratification, and novel therapeutic targets in these patients.

Predicting inflammatory bowel disease in children with abdominal pain and diarrhoea: calgranulin-C versus calprotectin stool tests

OBJECTIVE

Calgranulin-C (S100A12) is a new faecal marker of inflammation that is potentially more specific for inflammatory bowel disease (IBD) than calprotectin, since it is only released by activated granulocytes. We compared calgranulin-C and calprotectin to see which of the two tests best predicted IBD in children with chronic abdominal pain and diarrhoea.

DESIGN

Delayed-type cross-sectional diagnostic study.

SETTING AND PATIENTS

Previously undiagnosed patients aged 6-17 years, who were seen in paediatric clinics in the Netherlands and Belgium, sent in a stool sample for analysis. Patients with a high likelihood of IBD underwent upper and lower endoscopy (ie, preferred reference test), while those with a low likelihood were followed for 6 months for latent IBD to become visible (ie, alternative reference test). We used Bayesian modelling to correct for differential verification bias.

MAIN OUTCOME MEASURES

Primary outcome was the specificity for IBD using predefined test thresholds (calgranulin-C: 0.75 µg/g, calprotectin: 50 µg/g). Secondary outcome was the test accuracy with thresholds based on receiver operating characteristics (ROC) analysis.

RESULTS

IBD was diagnosed in 93 of 337 patients. Calgranulin-C had significantly better specificity than calprotectin when predefined thresholds were used (97% (95% credible interval (CI) 94% to 99%) vs 71% (95% CI 63% to 79%), respectively). When ROC-based thresholds were used (calgranulin-C: 0.75 µg/g, calprotectin: 400 µg/g), both tests performed equally well (specificity: 97% (95% CI 94% to 99%) vs 98% (95% CI 95% to 100%)).

CONCLUSIONS

Both calgranulin-C and calprotectin have excellent test characteristics to predict IBD and justify endoscopy.

TRIAL REGISTRATION NUMBER

NCT02197780.