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.

Activated Phosphoinositide 3 Kinase Delta Syndrome (APDS): A Primary Immunodeficiency Mimicking Lymphoma.

Malignant or nonmalignant lymphoproliferative disorders together with repeated ear, nose, and throat infections should strongly motivate immunologic investigations. Indeed, we report a 7-year-old patient with a history of persistent abdominal symptoms along with recurrent ear, nose, and throat infections, who presented with intra-abdominal masses highly suggestive of a diagnostic of lymphoma, and who was diagnosed with activated-PI3K-delta syndrome, a recently described primary immunodeficiency prone to lymphoproliferation.

Extraintestinal Manifestations of Pediatric Inflammatory Bowel Disease: Prevalence, Presentation, and Anti-TNF Treatment.

BACKGROUND: There is a paucity of data on extraintestinal manifestations (EIM) and their treatment in pediatric patients with inflammatory bowel disease (IBD). METHODS: Since 2008, the Pediatric Swiss IBD Cohort Study has collected data on the pediatric IBD population in Switzerland. Data on 329 patients were analyzed retrospectively. RESULTS: A total of 55 patients (16.7%) experienced 1-4 EIM (39 Crohn disease, 12 ulcerative colitis, and 4 IBD-unclassified patients). At IBD onset, presence of EIM was more frequent than in the adult population (8.5% vs 5.0%, P = 0.014). EIM were more frequent in Crohn disease when compared to ulcerative colitis/IBD-unclassified (22.5% vs 10.3%, P = 0.003). The most prevalent EIM were peripheral arthritis (26/329, 7.9%) and aphthous stomatitis (24/329, 7.3%). Approximately 27.6% of all EIM appeared before IBD diagnosis. Median time between IBD diagnosis and occurrence of first EIM was 1 month (-37.5-149.0). Thirty-one of the 55 patients (56.4%) were treated with 1 or more anti-tumor necrosis factor (TNF) agents. IBD patients with EIM were more likely to be treated with anti-TNF compared to those without (56.4% vs 35.0%, P = 0.003). Response rates to anti-TNF depended on underlying EIM and were best for peripheral arthritis (61.5%) and uveitis (66.7%). CONCLUSIONS: In a cohort of pediatric patients with IBD, EIM were frequently encountered. In up to 30%, EIM appeared before IBD diagnosis. Knowledge of these findings may translate into an increased awareness of underlying IBD, thereby decreasing diagnostic delay. Anti-TNF for the treatment of certain EIM is effective, although a substantial proportion of new EIM may present despite ongoing anti-TNF therapy.

Bacillus calmette-guerin infection in NADPH oxidase deficiency: defective mycobacterial sequestration and granuloma formation.

Patients with chronic granulomatous disease (CGD) lack generation of reactive oxygen species (ROS) through the phagocyte NADPH oxidase NOX2. CGD is an immune deficiency that leads to frequent infections with certain pathogens; this is well documented for S. aureus and A. fumigatus, but less clear for mycobacteria. We therefore performed an extensive literature search which yielded 297 cases of CGD patients with mycobacterial infections; M. bovis BCG was most commonly described (74%). The relationship between NOX2 deficiency and BCG infection however has never been studied in a mouse model. We therefore investigated BCG infection in three different mouse models of CGD: Ncf1 mutants in two different genetic backgrounds and Cybb knock-out mice. In addition, we investigated a macrophage-specific rescue (transgenic expression of Ncf1 under the control of the CD68 promoter). Wild-type mice did not develop severe disease upon BCG injection. In contrast, all three types of CGD mice were highly susceptible to BCG, as witnessed by a severe weight loss, development of hemorrhagic pneumonia, and a high mortality (∼ 50%). Rescue of NOX2 activity in macrophages restored BCG resistance, similar as seen in wild-type mice. Granulomas from mycobacteria-infected wild-type mice generated ROS, while granulomas from CGD mice did not. Bacterial load in CGD mice was only moderately increased, suggesting that it was not crucial for the observed phenotype. CGD mice responded with massively enhanced cytokine release (TNF-α, IFN-γ, IL-17 and IL-12) early after BCG infection, which might account for severity of the disease. Finally, in wild-type mice, macrophages formed clusters and restricted mycobacteria to granulomas, while macrophages and mycobacteria were diffusely distributed in lung tissue from CGD mice. Our results demonstrate that lack of the NADPH oxidase leads to a markedly increased severity of BCG infection through mechanisms including increased cytokine production and impaired granuloma formation.

Riboflavin in cyclic vomiting syndrome: efficacy in three children.

Cyclic vomiting syndrome is an episodic disorder considered to be a migraine variant. Riboflavin is efficient in the prophylactic treatment of migraines in adults. We describe the effectiveness and tolerance of riboflavin treatment in three children with cyclic vomiting syndrome. All of them fulfilled the diagnosis criteria for cyclic vomiting syndrome. They received prophylactic monotherapy with riboflavin for at least 12 months. Excellent response and tolerability was observed. CONCLUSION: Based on clinical observation in three cases, riboflavin may be an effective and safe prophylactic treatment for children with cyclic vomiting syndrome. WHAT IS KNOWN: CVS is one of the "childhood periodic syndromes" classified as a migraine subtype by the International Headache Society. Riboflavin is currently used as a prophylactic treatment in patients with migraine. WHAT IS NEW: Riboflavin may be an effective and safe prophylactic treatment for children with CVS. Increasing doses of riboflavin and long periods of prophylaxis may be needed in some children..

Functional gastro-intestinal disorder algorithms focus on early recognition, parental reassurance and nutritional strategies.

UNLABELLED: Up to 50% of infants present with symptoms of regurgitation, infantile colic and/or constipation during the first 12 months of life. Although they are often classed as functional disorders, there is an overlap with cows' milk allergy. We present practical algorithms for the management of such disorders, based on existing evidence and general consensus, with a particular focus on primary health care. Management consists of early recognition of warning signs of organic disease, parental reassurance and nutritional strategies. CONCLUSION: The proposed algorithms aim to help healthcare providers manage frequent gastrointestinal and cows' milk-related symptoms in infants safely and effectively.

An international consensus report on a new algorithm for the management of infant diarrhoea.

AIM: Implementing international guidelines guarantees high standards of clinical care. A group of experts developed an algorithm to drive the management of common gastrointestinal symptoms in infancy by paediatricians and general practitioners. METHODS: The algorithm started from the evidence-based recommendations of the European Society of Gastroenterology, Hepatology and Nutrition and the European Society of Pediatric Infectious Diseases and an updated review of the literature. We used the structured quantitative method of nominal group technique to reach a consensus. RESULTS: A practical algorithm for the management of infants with acute diarrhoea was designed based on the consensus reached for each statement. The management of an infant with acute diarrhoea should include a sequence of actions: (i) a semiquantitative estimate of infant dehydration through validated clinical scores, (ii) rehydration therapy and early refeeding with breast milk or regular formula and (iii) effective agents to reduce the severity and duration of the diarrhoea. Finally, in children with prolonged diarrhoea, the search for aetiology should include persistent infections or reinfections, cows' milk protein allergy and coeliac diseases. Lactose should always be withdrawn. CONCLUSION: This algorithm provides an evidence-based sequence of interventions to optimise the management of infants with acute diarrhoea.

Characterization of Crohn disease in X-linked inhibitor of apoptosis-deficient male patients and female symptomatic carriers.

BACKGROUND: Crohn disease is an inflammatory bowel disease (IBD) with a complex mode of inheritance. Although nucleotide binding and oligomerization domain containing 2 (NOD2) is the strongest risk factor, the cause of Crohn disease remains unknown in the majority of the cases. X-linked inhibitor of apoptosis (XIAP) deficiency causes X-linked lymphoproliferative syndrome type 2. IBD has been reported in some XIAP-deficient patients. OBJECTIVE: We characterize the IBD affecting a large cohort of patients with mutations in XIAP and examine the possible pathophysiologic mechanisms. METHODS: We performed a phenotypical and histologic analysis of the IBD affecting 17 patients with hemizygous mutations in XIAP, including 3 patients identified by screening 83 patients with pediatric-onset IBD. The X chromosome inactivation was analyzed in female carriers of heterozygous XIAP mutations, including 2 adults with IBD. The functional consequences of XIAP deficiency were analyzed. RESULTS: Clinical presentation and histology of IBD in patients with XIAP deficiency overlapped with those of patients with Crohn disease. The age at onset was variable (from 3 months to 41 years), and IBD was severe and difficult to treat. In 2 patients hematopoietic stem cell transplantation fully restored intestinal homeostasis. Monocytes of patients had impaired NOD2-mediated IL-8 and monocyte chemoattractant protein 1 (MCP-1) production, as well as IL-10, in response to NOD2 and Toll-like receptor 2/4 costimulation. Nucleotide binding and oligomerization domain containing 1 (NOD1)-mediated IL-6 and IL-8 production was defective in fibroblasts from XIAP-deficient patients. The 2 heterozygous female carriers of XIAP mutations with IBD displayed abnormal expression of the XIAP mutated allele, resulting in impaired activation of the NOD2 pathway. CONCLUSION: IBD in patients with XIAP deficiency is similar to Crohn disease and is associated with defective NOD2 function in monocytes. Importantly, we report that it is not restricted to male patients because we identified 2 symptomatic female heterozygous carriers of XIAP mutations.

Hyperinflammation of chronic granulomatous disease is abolished by NOX2 reconstitution in macrophages and dendritic cells.

Chronic granulomatous disease (CGD), caused by a lack of reactive oxygen species (ROS) generation by the phagocyte NADPH oxidase NOX2, leads to massively increased inflammatory responses. In order to identify the type of phagocyte which requires NOX2 activity to limit inflammation, we investigated mice with a loss of function mutation in the Ncf1 gene coding for the p$47^{\rm{phox}}$ subunit of NOX2 and mice with transgenic rescue of Ncf1 under control of the CD68 promoter. To induce CGD hyperinflammation, different mouse genotypes were injected intradermally with ß-glucan. Ncf1 mutant mice showed massive and prolonged hyperinflammation. Hyperinflammatory lesions were characterized by persistent neutrophilic infiltration, along with ulceration and necrosis. In contrast, in CD68 promoter rescue mice inflammation resolved within days, as seen in wild-type animals. Measurements of ROS in rescue mice demonstrated functional NOX2 in mononuclear phagocytes (macrophages and dendritic cells) but not in neutrophils. This absence of NOX2 function was also confirmed in inflammatory tissue neutrophils. Lack of functional NOX2 in mononuclear phagocytes increased the secretion of IL-1ß at early time points and of IL-6 and TNFα at later time points. Thus, CGD hyperinflammation is a redox dysregulation in mononuclear phagocytes, demonstrating a cell type-specific anti-inflammatory function of NOX2.

Is acute fibrinous and organizing pneumonia the expression of immune dysregulation?

INTRODUCTION: Acute fibrinous and organizing pneumonia (AFOP) is a recently described histologic pattern of diffuse pulmonary disease. In children, all cases reported to date have been fatal. In this study, we describe the first nonfatal AFOP in a child and review the literature. DESCRIPTION: A 10-year-old boy developed very severe aplastic anemia (VSAA) after being admitted to our hospital with a fulminant hepatic failure of unknown origin. A chest computed tomography scan revealed multiple lung nodules and a biopsy of a pulmonary lesion showed all the signs of AFOP. Infectious workup remained negative. We started immunosuppressive therapy with antithymocyte globulin and cyclosporine to treat VSAA. Subsequent chest computed tomography scans showed a considerable diminution of the lung lesions but the VSAA did not improve until we performed hematopoietic stem cell transplantation 5 months later. CONCLUSIONS: Aplastic anemia is associated with a variety of autoimmune syndromes. The sequence of events in our patient suggests that the hepatic failure, AFOP, and the VSAA may all have been part of an autoimmune syndrome. AFOP could be the result of immune dysregulation in this pediatric case with favorable outcome after immunosuppressive therapy and hematopoietic stem cell transplantation.

Protective antibody responses to influenza A/H1N1/09 vaccination in children with celiac disease.

Patients with celiac disease have an increased risk for severe influenza infection and they show less of a response to certain vaccine types. During the influenza A/H1N1/09 pandemic, we prospectively investigated pandemic vaccine responses in 14 pediatric patients with celiac disease and age-/sex-matched controls. All of the children with celiac disease reached protective antibody titers (≥40) and showed a geometric mean titer comparable with the control group (530 vs 573).

NADPH oxidase-1 plays a crucial role in hyperoxia-induced acute lung injury in mice.

RATIONALE: Hyperoxia-induced acute lung injury has been used for many years as a model of oxidative stress mimicking clinical acute lung injury and the acute respiratory distress syndrome. Excess quantities of reactive oxygen species (ROS) are responsible for oxidative stress-induced lung injury. ROS are produced by mitochondrial chain transport, but also by NADPH oxidase (NOX) family members. Although NOX1 and NOX2 are expressed in the lungs, their precise function has not been determined until now. OBJECTIVES: To determine whether NOX1 and NOX2 contribute in vivo to hyperoxia-induced acute lung injury. METHODS: Wild-type and NOX1- and NOX2-deficient mice, as well as primary lung epithelial and endothelial cells, were exposed to room air or 100% O(2) for 72 hours. MEASUREMENTS AND MAIN RESULTS: Lung injury was significantly prevented in NOX1-deficient mice, but not in NOX2-deficient mice. Hyperoxia-dependent ROS production was strongly reduced in lung sections, in isolated epithelial type II cells, and lung endothelial cells from NOX1-deficient mice. Concomitantly, lung cell death in situ and in primary cells was markedly decreased in NOX1-deficient mice. In wild-type mice, hyperoxia led to phosphorylation of c-Jun N-terminal kinase (JNK) and extracellular signal-regulated kinase (ERK), two mitogen-activated protein kinases involved in cell death signaling, and to caspase-3 activation. In NOX1-deficient mice, JNK phosphorylation was blunted, and ERK phosphorylation and caspase-3 activation were decreased. CONCLUSIONS: NOX1 is an important contributor to ROS production and cell death of the alveolocapillary barrier during hyperoxia and is an upstream actor in oxidative stress-induced acute lung injury involving JNK and ERK pathways in mice.

Lymphocytic leiomyositis and myenteric ganglionitis are intrinsic features of cystic fibrosis: studies in distal intestinal obstruction syndrome and meconium ileus.

BACKGROUND: Cystic fibrosis (CF) is a multisystem disorder intrinsically associated with inflammation of mucosal surfaces. Because inflammation can result in enteric neuromuscular dysfunction we hypothesized that terminal ileitis in patients with CF may predispose to distal ileal obstruction syndrome (DIOS). METHODS AND PATIENTS: Full-thickness terminal ileal tissues from 6 children with CF and severe DIOS, 6 infants with complicated meconium ileus (MI), and 6 children with non-CF intestinal atresia were studied. RESULTS: Lymphocyte-predominant mucosal and transmural ileal inflammation was present in 6 of 6 patients with DIOS. Lymphocytic ganglionitis was present in 4 of 6 although numbers of myenteric neurons were not decreased (5/5). Myocyte proteins were preserved (6/6). Mild submucosal fibrosis was common in DIOS (5/6) and transformation of submucosal fibroblasts to a myofibroblastic phenotype was noted in 4 of 6. Inflammatory changes were distinct from those described in fibrosing colonopathy. Antroduodenal manometry in an individual who had experienced MI/DIOS was consistent with a neuropathic pseudo-obstructive process. Submucosal or transmural lymphocyte predominant inflammation was also present in 6 of 6 infants with complicated MI, which, when coupled with submucosal myofibroblast proliferation (5/6), appeared highly predictive of CF rather than non-CF atresia. Histological findings at birth were similar, although milder, than those seen in DIOS, suggesting that these changes are a primary abnormality in CF. CONCLUSIONS: Submucosal or transmural inflammation of the ileum is common in newborns with CF and MI and older children with DIOS. Severe recurrent DIOS should be investigated with seromuscular and mucosal biopsy of the ileum to seek a transmural ileitis potentially amenable to anti-inflammatory therapies.

Food poisoning as a cause of acute liver failure.

We report a 9-year-old girl with cereulide-producing Bacillus cereus food poisoning, who developed fulminant hepatitis, renal and pancreatic insufficiency, shock, and prolonged seizures. She was transferred to our institution for hepatic transplantation before her diagnosis was established. As a result of rapid identification of the microorganism and supportive care, liver transplantation was avoided, and she recovered fully.

Focal ischemic necrosis in advanced biliary atresia cirrhosis.

This report correlates the clinical and biological findings, liver hemodynamics and histological features of focal INL in an infant with BA cirrhosis. An eight month old boy with BA, with previous successful porto-enterostomy, was admitted with signs of cholangitis and ascites. He was treated with antibiotics and diuretics with subsequent clinical improvement. Eight days later, while being fed with hyper-osmolar milk, he became febrile again: ASAT/ALAT climbed (9000/2300 IU/L), liver function deteriorated. Infectious work-up was negative. Liver-ultrasound showed reversed portal flow and a negative arterial diastolic flow. The patient recovered within five days under supportive treatment. A similar event recurred five days later. INL was suspected and semi-urgent living-related liver transplantation was performed, with uneventful post-operative course. Histology of the explanted liver showed extensive foci of INL of different ages. This report illustrates how the association of reversed portal and arterial diastolic flows, with subsequent liver hypoperfusion, may repeatedly cause foci of INL in BA cirrhosis, and lead to rapid progression to liver failure. Because of precarious hepatic blood supply in such patients, close monitoring of portal and diastolic arterial flows is recommended.

Mast cell-nerve interactions in children with functional dyspepsia.

BACKGROUND AND AIMS: Functional dyspepsia in childhood is commonly triggered by food allergen in sensitised individuals. We investigated the topography of eosinophils and mast cells in gastric antral lamina propria, the interaction of mast cell products with mucosal nerve fibres, and changes in gastric antral muscle slow wave activity in children with atopy and non-atopy-related functional dyspepsia. PATIENTS AND METHODS: Open label study of gastric mucosal cow's milk challenge in 10 atopic and 6 nonatopic children (ages 2-12 years) investigated consecutively with gastroscopy for functional dyspepsia. Simultaneous surface electrogastrography and milk challenge were undertaken and laser scanning fluorescence microscopy used to examine the association of mast cell tryptase with mucosal nerves in the gastric mucosa before and after challenge. RESULTS: Eosinophils and mast cells within the lamina propria were increased in number in children with atopic functional dyspepsia and degranulated rapidly after cow's milk challenge in the atopic group. For degranulating eosinophils, median = 13.0% (interquartile range = 3.7-31.0) premilk versus 32.0% (12.0-42.0) after milk biopsies (P < 0.05); for degranulating mast cells, 5.35% (2.7-10.9) premilk biopsies versus 18.75% (12.9-22.1) after milk biopsies (P < 0.05). No such differences were seen in nonatopic patients. Mast cells were closely associated with mucosal nerve fibres and released tryptase, which colocalised with proteinase-activated receptors on mucosal nerve fibres. The gastric antral slow wave became abnormal within 2 minutes of antigen challenge in atopics with an increase in dominant frequency instability coefficient (P < 0.005), decrease in 3 cycles per minute myoelectrical activity (P < 0.01), and increase in bradygastria (P < 0.01). CONCLUSIONS: Early-onset neuroimmune interactions induced by cow's milk in the gastric mucosa of atopic children are associated with rapid disturbance of gastric myoelectrical activity and dyspeptic symptoms.

Severe autoimmune hemolytic anemia in a liver transplanted child.

AIHA can complicate solid organ and bone marrow transplantation early after transplant. We describe the first case report of a 16-month-old boy with mixed type warm-acting IgM and warm IgG autoantibodies AIHA, occurring eight months after liver transplantation. This case describes the complexity of this very rare form of AIHA. It also illustrates the efficacy of rituximab in this indication, as well as the transfusion support with extremely rare blood, along with the importance of international collaboration to provide it. In this report, the etiologies of HA occurring in post-transplant pediatric patients are reviewed and the different treatment strategies are discussed.

Decreased blood pressure in NOX1-deficient mice.

To understand the role of the superoxide-generating NADPH oxidase NOX1 in the vascular system, we have generated NOX1-deficient mice. NOX1-deficient mice had a moderately decreased basal blood pressure. In response to angiotensin II they showed an almost complete loss of the sustained blood pressure response, while the initial increase was conserved. NOX1-deficient mice showed a marked reduction in aortic media hypertrophy. Angiotensin II-induced smooth muscle cell proliferation was conserved, but there was a marked decrease in extracellular matrix accumulation. Our results establish a role for NOX1 in blood pressure regulation and vascular angiotensin II response.