Calprotectin: Clinical Applications in Pediatrics

Home-based fecal calprotectin utilization in a general pediatric gastroenterology clinic

OBJECTIVE

Remote investigation and monitoring have gained importance in ambulatory practice. A home-based fecal calprotectin (FC) test has been developed where the sample is processed and analyzed at home through a smartphone application. We aimed to assess the use of standard ELISA (sFC) versus home-based (hFC) FC testing in a general pediatric gastroenterology clinic.

METHODS

Ambulatory pediatric patients with hFC or sFC performed between August 2019 and November 2020 were included. Data regarding demographics, clinical characteristics, medication use, investigations, and final diagnosis, categorized as inflammatory bowel disease (IBD), functional gastrointestinal (GI) disorders, organic non-IBD (ONI) GI disorders, non-GI disorders, and undetermined after 6 months of investigation, were recorded.

RESULTS

A total of 453 FC tests from 453 unique patients were included. Of those, 249 (55%) were hFC. FC levels (median) were higher in children with IBD compared to non-IBD diagnosis (sFC 795 vs. 57 μg/g, hFC 595 vs. 47 μg/g, p < 0.001), and in ONI compared to functional GI disorders (sFC 85 vs. 54 μg/g, p = 0.003, hFC 57 vs. 40 μg/g, p < 0.001). No significant difference was observed between different ONI GI disorders or subtypes of functional disorders. Age did not significantly influence levels.

CONCLUSIONS

Overall, hFC and sFC provide similar results in the general pediatric GI ambulatory setting. FC is a sensitive but not disease-specific marker to identify patients with IBD. Values appear to be higher in ONI GI disorders over functional disorders, although cut-off values have yet to be determined.

Factors associated with anaemia among preschool- age children in underprivileged neighbourhoods in Antananarivo, Madagascar

BACKGROUND

Anaemia occurs in children when the haemoglobin level in the blood is less than the normal (11 g/dL), the consequence is the decrease of oxygen quantity in the tissues. It is a prevalent public health problem in many low-income countries, including Madagascar, and data on risk factors are lacking. We used existing data collected within the pathophysiology of environmental enteric dysfunction (EED) in Madagascar and the Central African Republic project (AFRIBIOTA project) conducted in underprivileged neighbourhoods of Antananarivo to investigate the factors associated with anaemia in children 24 to 59 months of age.

METHODS

Children included in the AFRIBIOTA project in Antananarivo for whom data on haemoglobin and ferritin concentrations were available were included in the study. Logistic regression modelling was performed to identify factors associated with anaemia.

RESULTS

Of the 414 children included in this data analysis, 24.4% were found to suffer from anaemia. We found that older children (adjusted OR: 0.95; 95% CI: 0.93-0.98) were less likely to have anaemia. Those with iron deficiency (adjusted OR: 6.1; 95% CI: 3.4-11.1) and those with a high level of faecal calprotectin (adjusted OR: 2.5; 95% CI: 1.4-4.4) were more likely to have anaemia than controls.

CONCLUSIONS

To reduce anaemia in the children in this underprivileged area, more emphasis should be given to national strategies that improve children's dietary quality and micronutrient intake. Furthermore, existing measures should be broadened to include measures to reduce infectious disease burden.

Gastrointestinal manifestations and their relation to faecal calprotectin in children with autism

Introduction

A common comorbidity in autism spectrum disorder (ASD) children is gastrointestinal problems, and a possible link between active gastrointestinal inflammation and autism has been suggested. Faecal calprotectin (FC) is a non-invasive marker for of gastrointestinal inflammation.

Aim

To study the level of FC as a marker of bowel inflammation in children with ASD and its possible relation to gastrointestinal manifestations.

Material and methods

Calprotectin levels were assessed in stool samples of 40 ASD children. Autism severity was assessed by the Childhood Autism Rating Scale (CARS). Severity of gastrointestinal symptoms was assessed using a modified version of the 6-Item Gastrointestinal Severity Index (6-GSI) questionnaire. A control group of 40 healthy children matched for age and sex with the cases was also included to compare their levels of FC.

Results

Gastrointestinal symptoms were present in 82.5% of children with autism; the most reported offensive stool odour (70%) and the least diarrhoea (17.5%), and a high 6-GSI score was observed in 35% of ASD children. FC levels were elevated in 35% of the cases and in 25% of the control group. The mean levels of FC of cases were significantly elevated compared to levels of controls. FC levels positively correlated with severity of gastrointestinal symptoms (6-GSI) in autistic patients. There was positive correlation between CARS and 6-GSI.

Conclusions

Gastrointestinal manifestations are a common comorbidity in autistic patients. ASD patients have significantly higher FC levels than healthy controls. FC levels are strongly correlated with the severity of gastrointestinal manifestations in ASD children. So, gastrointestinal manifestations among autistic patients could be caused by gastrointestinal inflammation.

Fecal calprotectin levels in pediatric cow's milk protein allergy

INTRODUCTION

The most prevalent food allergy in younger children is cow's milk protein allergy (CMPA), a hypersensitivity reaction to cow's milk protein and its most common clinical manifestation is allergic colitis. The goal of our recent study was to assess somatic symptoms of CMPA and to prospectively observe the effects of a dairy elimination diet using objective parameters and questionnaires.

METHODS

The County Hospital in Szekszárd, Hungary, investigated children aged 1 to 18 who had clinical signs that might indicate CMPA. Stool samples were taken and analyzed using a fecal calprotectin (FC) rapid test (Quantum Blue fCAL, Bühlmann Laboratories, Switzerland) at the time of the diagnosis and following 3 months of an elimination diet. At the baseline visit as well as the first and second follow-up, questionnaires were filled out. Patients were divided into two subgroups according to dietary guidelines based on the results of the questionnaires.

RESULTS

A total of 47 patients participated in the study [42.55% female, mean age: 7.36 (SD 4.22) years]. There was no significant difference in FC levels between baseline and after 3-month elimination diet [73.98 (71.12) μg/g and 68.11 (74.4) μg/g, respectively, p = 0.331]. After three months, there was a significant decrease in FC levels among patients who adhered to the strict diet [84.06 (79.48) μg/g and 41.11 (34.24) μg/g, respectively, p = 0.001].

CONCLUSION

The findings of our study suggest that FC can be an objective marker in confirming the diagnosis of CMPA. Significant improvement in clinical symptoms and in FC levels can only be expected after a strictly followed elimination diet.

Use of faecal immunochemical testing as an alternative to faecal calprotectin in children

BACKGROUND

Faecal calprotectin has been widely used as a non-invasive marker of intestinal inflammation in children. Measurement of faecal haemoglobin using faecal immunochemical test is well established in adults for detection of colorectal cancer. In adults, faecal haemoglobin has been recommended as a reliable tool to aid identification of those at low risk of significant bowel disease and has also been used in inflammatory bowel disease to assess mucosal healing.

AIMS

We aimed to evaluate the performance of faecal haemoglobin in the paediatric population and compare it with faecal calprotectin.

METHODS

Children being assessed in the paediatric gastroenterology clinic for bowel symptoms had a sample sent for both faecal calprotectin and faecal haemoglobin. Samples were collected over a 10-month period from November 2018 to September 2019. Faecal haemoglobin was measured using an OC-Sensor. Faecal calprotectin was measured using Liason®Calprotectin.

RESULTS

One hundred forty three samples were returned for faecal haemoglobin and in 107 a paired faecal calprotectin was also available. Faecal haemoglobin correlated with faecal calprotectin, Spearman's rank coefficient 0.656 (P < 0.0001). There were 35 patients with faecal haemoglobin >20 μg/g and in 32 of these patients faecal calprotectin was >200 μg/g; 74 patients with faecal haemoglobin and 38 patients with faecal calprotectin underwent colonoscopy. Patients with normal histology had faecal haemoglobin <4 μg/g; faecal haemoglobin >20 µg/g was associated with signification inflammation.

CONCLUSION

Our study is the first to compare faecal haemoglobin and faecal calprotectin in a paediatric population. Results suggest that faecal haemoglobin correlates with faecal calprotectin and, as in adults, may be useful to rule out significant bowel disease. A faecal haemoglobin >20 μg/g was consistent with significant histological inflammation.

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.

Effects of unsaturated fatty acids (Arachidonic/Oleic Acids) on stability and structural properties of Calprotectin using molecular docking and molecular dynamics simulation approach

Calprotectin is a heterodimeric protein complex with two subunits called S100A8/A9. The protein has an essential role in inflammation process and various human diseases. It has the ability to bind to unsaturated fatty acids including Arachidonic acid, Oleic acid and etc., which could be considered as a major carrier for fatty acids. In this study we aimed to appraise the thermodynamics and structural changes of Calprotectin in presence of Arachidonic acid/Oleic acid) using docking and molecular dynami simulation method. To create the best conformation of Calprotectin-Oleic acid/Arachidonic acid complexes, the docking process was performed. The complexes with the best binding energy were selected as the models for molecular dynamics simulation process. Furthermore, the structural and thermodynamics properties of the complexes were evaluated too. The Root Mean Square Deviation and Root Mean Square Fluctuation results showed that the binding of Arachidonic acid/Oleic acid to Calprotectin can cause the protein structural changes which was confirmed by Define Secondary Structure of Proteins results. Accordingly, the binding free energy results verified that binding of Oleic acid to Calprotectin leads to instability of S100A8/A9 subunits in the protein. Moreover, the electrostatic energy contribution of the complexes (Calprotectin-Oleic acid/Arachidonic acid) was remarkably higher than van der Waals energy. Thus, the outcome of this study confirm that Oleic acid has a stronger interaction with Calprotectin in comparison with Arachidonic acid. Our findings indicated that binding of unsaturated fatty acids to Calprotectin leads to structural changes of the S100A8/A9 subunits which could be beneficial to play a biological role in inflammation process.

Natural chemotherapeutic alternatives for controlling of haemonchosis in sheep

BACKGROUND

Parallel in vitro and in vivo experiments were designed to evaluate promising chemotherapeutic alternatives for controlling haemonchosis in ruminants. In vitro anthelmintic activities (egg hatch test - EHT; larval development test - LDT) of aqueous and methanolic herbal extracts Mix1 and Mix2 were investigated. The in vivo effects of dietary supplementation with Mix1 and Mix2 on the parasitological status, inflammatory response, antioxidant parameters and microbial community of the lambs infected experimentally with Haemonchus contortus were investigated. Lambs were divided into four groups for the in vivo study: uninfected control lambs (C), infected lambs (I), infected lambs supplemented with Mix1 (I + Mix1) and infected lambs supplemented with Mix2 (I + Mix2). The experimental period was 70 days.

RESULTS

The number of eggs per gram (EPG) of feces was quantified 22, 30, 37, 44, 51, 58, 65 and 70 days post-infection, and mean abomasal worm counts were assessed 70 days post-infection. Quantitative analyses identified 57.3 and 22.2 mg/g phenolic acids, 41.5 and 29.5 mg/g flavonoids and 1.4 and 1.33 mg/g protoberberine-type alkaloids in Mix1 and Mix2, respectively. The methanolic extracts of the herbal mixtures in both in vitro tests had higher anthelmintic effects (P < 0.01) than the aqueous extracts, but the effects did not differ significantly between Mix1 and Mix2 (P > 0.05). I + Mix1 and I + Mix2 lowered mean EPGs between 44 and 70 d by 58.1 and 51.6%, respectively. The level of IgG antibodies against H. contortus increased significantly after infection in each infected group.

CONCLUSION

These results represent the first monitoring of the in vitro anthelmintic effects of herbal mixtures on H. contortus. The in vivo experiment indicated that the anthelmintic effect was not sufficient for the elimination of parasites, but this herbal treatment may affect the host over a longer term, reducing the parasitic infection in the host.

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.

Implications of hepatic dysfunction in Kawasaki disease: Time-related changes in aspartate aminotransferase, alanine aminotransferase, total bilirubin, and C-reactive protein levels

IMPORTANCE

The cause of the hepatic dysfunction that commonly accompanies Kawasaki disease (KD) remains unclear.

OBJECTIVE

We tried to clarify the cause of the hepatic dysfunction.

METHODS

A total of 381 consecutive patients with acute KD, who had undergone inpatient treatment with intravenous immunoglobulin until the 7th day of illness, were divided into a group of 199 patients with an alanine aminotransferase (ALT) level ≥ 40 IU/L on admission (group I), a group of 52 patients with an ALT level ≥ 40 IU/L at some point after admission (group II), and a group of 130 patients with ALT levels consistently < 40 IU/L throughout hospitalization (group III). Aspartate aminotransferase (AST), ALT, total bilirubin (T-Bil), and C-reactive protein (CRP) levels were analyzed over time, and time-courses were compared.

RESULTS

In the initial stage of illness, in group I, AST, ALT, T-Bil peaked on days 1-3, and AST tended to improve significantly on the 4th day (P < 0.001). T-Bil improved on day 5 (P < 0.01), and ALT improved significantly on day 6 (P < 0.001). CRP increased every day up to day 6 (P < 0.001). In group II, AST and ALT increased after admission, and thereafter CRP increased, then decreased. The frequency of use of aspirin and aspirin doses did not differ significantly in the three groups.

INTERPRETATION

Recovery from liver dysfunction occurred in the initial stage of illness in group I-within the period of CRP exacerbation, which is an indicator of systemic inflammation.

Measuring calprotectin in plasma and blood with a fully automated turbidimetric assay

Calprotectin in plasma and blood might prove to be a useful biomarker of inflammation and infection; however, automated methods for analysing the concentration of calprotectin in those materials are lacking. We have validated a fully automated turbidimetric method and present health-related reference limits. Calprotectin was measured by Siemens Advia XPT with the Bühlmann fCAL® turbo test (Bühlmann Laboratories AG, Schönenbuch, Switzerland), a particle enhanced turbidimetric immunoassay for quantification of calprotectin in fecal extracts. Plasma and serum samples were analysed directly, while whole blood was first extracted with M-PER® Mammalian Protein Extraction Reagent (ThermoFisher) and diluted with B-CAL-EX (Bühlmann). We studied analytical imprecision, estimated health-related reference limits and examined the correlation between neutrophil-calprotectin (blood-calprotectin adjusted for plasma-calprotectin) and the neutrophil count. The intermediate ('day-to-day') coefficient of variation was 3.5 and 1.0% for heparin-plasma-calprotectin at 0.52 mg/L and 3.53 mg/L, respectively, and 4.9% for heparin-blood-calprotectin at 50.2 mg/L. Health-related reference limits were 0.470-3.02 mg/L for calprotectin in heparin-plasma, 50.8-182 mg/L for calprotectin in heparin-blood, 0.534-2.41% for the ratio between them and 24.7-33.3 pg for the mean amount of calprotectin per neutrophil. Compared to heparin-plasma, calprotectin concentrations were significantly lower in EDTA-plasma and higher in serum (p < .05). Correlation between neutrophil-calprotectin and the neutrophil count was excellent. We have shown that the Bühlmann fCAL® turbo test can be used to measure calprotectin in plasma and blood.

Colonization by B. infantis EVC001 modulates enteric inflammation in exclusively breastfed infants

BACKGROUND

Infant gut dysbiosis, often associated with low abundance of bifidobacteria, is linked to impaired immune development and inflammation-a risk factor for increased incidence of several childhood diseases. We investigated the impact of B. infantis EVC001 colonization on enteric inflammation in a subset of exclusively breastfed term infants from a larger clinical study.

METHODS

Stool samples (n = 120) were collected from infants randomly selected to receive either 1.8 × 10¹⁰ CFU B. infantis EVC001 daily for 21 days (EVC001) or breast milk alone (controls), starting at day 7 postnatal. The fecal microbiome was analyzed using 16S ribosomal RNA, proinflammatory cytokines using multiplexed immunoassay, and fecal calprotectin using ELISA at three time points: days 6 (Baseline), 40, and 60 postnatal.

RESULTS

Fecal calprotectin concentration negatively correlated with Bifidobacterium abundance (P < 0.0001; ρ = -0.72), and proinflammatory cytokines correlated with Clostridiaceae and Enterobacteriaceae, yet negatively correlated with Bifidobacteriaceae abundance. Proinflammatory cytokines were significantly lower in EVC001-fed infants on days 40 and 60 postnatally compared to baseline and compared to control infants.

CONCLUSION

Our findings indicate that gut dysbiosis (absence of B. infantis) is associated with increased intestinal inflammation. Early addition of EVC001 to diet represents a novel strategy to prevent enteric inflammation during a critical developmental phase.

Diagnostic Accuracy of Serum and Urine S100A8/A9 and Serum Amyloid A in Probable Acute Abdominal Pain at Emergency Department

Study Design

This study was performed to investigate the diagnostic values of some inflammatory biomarkers in abdominal pain.

Methods

Patients over 18 years of age with acute recent abdominal pain who presented to the Emergency Department were evaluated. Serum and urinary samples were taken and evaluated for serum and urine S100A8/A9 and serum amyloid A. All patients were referred to a surgeon and were followed up until the final diagnosis. In the end, the final diagnosis was compared with the levels of biomarkers.

Results

Of a total of 181 patients, 71 underwent surgery and 110 patients did not need surgery after they were clinically diagnosed. Mean levels of serum and urine S100A8/A9 had a significant difference between two groups, but serum amyloid A did not show. The diagnostic accuracy of serum S100A8/A9, urine S100A8/A9, and serum amyloid A was 86%, 79%, and 50%, respectively, in anticipation of the need or no need for surgery in acute abdominal pain.

Conclusions

Our study showed that in acute abdominal pain, serum and urine S100A8/A9 can be useful indicators of the need for surgery, but serum amyloid A had a low and nonsignificant diagnostic accuracy.

Effects of herbal nutraceuticals and/or zinc against Haemonchus contortus in lambs experimentally infected

Background

The gastrointestinal parasitic nematode Haemonchus contortus is a pathogenic organism resistant to several anthelmintics. This study assessed the efficacy of a medicinal herbal mixture (Herbmix) and organic zinc, as an essential trace element for the proper functioning of both unspecific and specific immune defensive mechanisms, against experimental infections with H. contortus in lambs. All lambs were infected orally with approximately 5000 third-stage larvae of a strain of H. contortus susceptible to anthelmintics (MHco1). Twenty-four female lambs 3–4 months of age were divided into four groups: unsupplemented animals (control), animals supplemented with Herbmix (Hmix), animals supplemented with organic zinc (Zn) and animals supplemented with Herbmix and organic zinc (Hmix+Zn). Eggs per gram (EPG) of faeces were quantified 20, 28, 35, 42, 49, 56, 62 and 70 d post-infection and mean abomasal worm counts were assessed 70 d post-infection. Samples of blood were collected from each animal 7, 35, 49 and 70 d post-infection.

Results

Quantitative analyses of the bioactive compounds in Herbmix identified three main groups: flavonoids (9964.7 μg/g), diterpenes (4886.1 μg/g) and phenolic acids (3549.2 μg/g). Egg counts in the lambs treated with Hmix, Zn and Hmix+Zn decreased after 49 d. The EPGs in the Zn and Hmix+Zn groups were significantly lower on day 56 (P < 0.05 and P < 0.01, respectively), and the EPGs and mean worm counts were significantly lower on day 70 in all supplemented groups (P < 0.05 and P < 0.01). Hemograms of complete red blood cells of each animal identified clinical signs of haemonchosis after day 35. Serum calprotectin concentrations and IgA levels were significantly affected by treatment. The treatment influenced serum malondialdehyde concentrations (P < 0.05) and sulfhydryl groups (P < 0.01) of antioxidant status. The mineral status was unaltered in all lambs.

Conclusion

A direct anthelmintic impact on the viability of nematodes was not fully demonstrated, but the treatments with herbal nutraceuticals and zinc likely indirectly contributed to the increase in the resistance of the lambs to nematode infection.

Combinatorial Omics Analysis Reveals Perturbed Lysosomal Homeostasis in Collagen VII-deficient Keratinocytes

The extracellular matrix protein collagen VII is part of the microenvironment of stratified epithelia and critical in organismal homeostasis. Mutations in the encoding gene COL7A1 lead to the skin disorder dystrophic epidermolysis bullosa (DEB), are linked to skin fragility and progressive inflammation-driven fibrosis that facilitates aggressive skin cancer. So far, these changes have been linked to mesenchymal alterations, the epithelial consequences of collagen VII loss remaining under-addressed. As epithelial dysfunction is a principal initiator of fibrosis, we performed a comprehensive transcriptome and proteome profiling of primary human keratinocytes from DEB and control subjects to generate global and detailed images of dysregulated epidermal molecular pathways linked to loss of collagen VII. These revealed downregulation of interaction partners of collagen VII on mRNA and protein level, but also increased abundance of S100 pro-inflammatory proteins in primary DEB keratinocytes. Increased TGF-β signaling because of loss of collagen VII was associated with enhanced activity of lysosomal proteases in both keratinocytes and skin of collagen VII-deficient individuals. Thus, loss of a single structural protein, collagen VII, has extra- and intracellular consequences, resulting in inflammatory processes that enable tissue destabilization and promote keratinocyte-driven, progressive fibrosis.