Genetic landscape of pediatric acute liver failure of indeterminate origin.

BACKGROUND AND AIMS: Pediatric acute liver failure (PALF) is a life-threatening condition. In Europe, the main causes are viral infections (12%-16%) and inherited metabolic diseases (14%-28%). Yet, in up to 50% of cases the underlying etiology remains elusive, challenging clinical management, including liver transplantation. We systematically studied indeterminate PALF cases referred for genetic evaluation by whole-exome sequencing (WES), and analyzed phenotypic and biochemical markers, and the diagnostic yield of WES in this condition. APPROACH AND RESULTS: With this international, multicenter observational study, patients (0-18 y) with indeterminate PALF were analyzed by WES. Data on the clinical and biochemical phenotype were retrieved and systematically analyzed. RESULTS: In total, 260 indeterminate PALF patients from 19 countries were recruited between 2011 and 2022, of whom 59 had recurrent PALF. WES established a genetic diagnosis in 37% of cases (97/260). Diagnostic yield was highest in children with PALF in the first year of life (41%), and in children with recurrent acute liver failure (64%). Thirty-six distinct disease genes were identified. Defects in NBAS (n=20), MPV17 (n=8), and DGUOK (n=7) were the most frequent findings. When categorizing, the most frequent were mitochondrial diseases (45%), disorders of vesicular trafficking (28%), and cytosolic aminoacyl-tRNA synthetase deficiencies (10%). One-third of patients had a fatal outcome. Fifty-six patients received liver transplantation. CONCLUSIONS: This study elucidates a large contribution of genetic causes in PALF of indeterminate origin with an increasing spectrum of disease entities. The high proportion of diagnosed cases and potential treatment implications argue for exome or in future rapid genome sequencing in PALF diagnostics.

Very-early-onset Inflammatory Bowel Disease in an Infant with a Partial RIPK1 Deletion.

The monogenic causes of very-early-onset inflammatory bowel disease (VEO-IBD) have been defined by genetic studies, which were usually related to primary immunodeficiencies. Receptor-interacting serine/threonine-protein kinase-1 (RIPK1) protein is an important signalling molecule in inflammation and cell death pathways. Its deficiency may lead to various clinical features linked to immunodeficiency and/or inflammation, including IBD. Here, we discuss an infant with malnutrition, VEO-IBD, recurrent infections and polyathritis who has a homozygous partial deletion in RIPK1 gene.

Training in Paediatric Clinical Nutrition Across Europe: A Survey of the National Societies Network (2016-2019) of the European Society for Paediatric Gastroenterology, Hepatology and Nutrition.

OBJECTIVES/BACKGROUND: Disease-related malnutrition is common in patients with chronic diseases and has detrimental effects, therefore, skills in nutrition care are essential core competencies for paediatric digestive medicine. The aim of this survey, conducted as part of a global survey of paediatric gastroenterology, hepatology and nutrition (PGHN) training in Europe, was to assess nutrition care-related infrastructure, staff, and patient volumes in European PGHN training centres. METHODS: Standardized questionnaires related to clinical nutrition (CN) care were completed by representatives of European PGHN training centres between June 2016 and December 2019. RESULTS: One hundred training centres from 17 European countries, Turkey, and Israel participated in the survey. Dedicated CN clinics exist in 66% of the centres, with fulltime and part-time CN specialists in 66% and 42%, respectively. Home tube feeding (HTF) andhome parenteral nutrition (HPN) programmes are in place in 95% and 77% of centres, respectively. Twenty-four percent of centres do not have a dedicated dietitian and 55% do not have a dedicated pharmacist attached to the training centre. Even the largest centres with >5000 outpatients reported that 25% and 50%, respectively do not have a dedicated dietitian or pharmacist. Low patient numbers on HTF and HPN of <5 annually are reported by 13% and 43% of centres, respectively. CONCLUSIONS: The survey shows clear differences and deficits in Clinical Nutrition training infrastructure, including staff and patient volumes, in European PGHN training centres, leading to large differences and limitations in training opportunities in Clinical Nutrition.

Peginterferon Alfa-2a (40KD) Plus Lamivudine or Entecavir in Children With Immune-Tolerant Chronic Hepatitis B.

OBJECTIVE: Treatment guidelines for chronic hepatitis B (CHB) do not recommend antiviral therapy for patients in the immune-tolerant phase of the disease, which generally occurs in children who acquire hepatitis B virus (HBV) vertically and may last for decades. On the basis of promising results of a pilot study, we conducted a randomized, controlled, multicenter study to evaluate the efficacy and safety of antiviral therapy in children and adolescents with immune-tolerant CHB. METHODS: Fifty-nine children aged 3 to <18 years hepatitis B e antigen-positive with an HBV DNA titer >20,000 IU/mL and persistently normal alanine aminotransferase levels were randomized to 56 weeks of antiviral therapy with an oral nucleoside analogue [entecavir or lamivudine], combined with subcutaneous peginterferon alfa-2a from week 8, or 80 weeks of untreated observation. The primary efficacy outcome was hepatitis B surface antigen loss 24 weeks post-treatment in the antiviral therapy group or at the end of observation in the control group. RESULTS: Enrollment was terminated after the results of two similar studies showed that similar antiviral regimens were ineffective in children and adults with immune-tolerant CHB. At 24 weeks post-treatment, 1 of 26 patients in the antiviral treatment group experienced HBsAg loss (vs none of 33 patients in the control group). No serious treatment-related adverse events were reported, and no patients discontinued treatment because of adverse events. CONCLUSIONS: The antiviral regimen evaluated in this trial had an acceptable tolerability profile, but was ineffective in children and adolescents with immune-tolerant CHB.

Transaldolase haploinsufficiency in subjects with acetaminophen-induced liver failure.

Transaldolase (TAL) is an enzyme in the pentose phosphate pathway (PPP) that generates NADPH for protection against oxidative stress. While deficiency of other PPP enzymes, such as transketolase (TKT), are incompatible with mammalian cell survival, mice lacking TAL are viable and develop progressive liver disease attributed to oxidative stress. Mice with homozygous or heterozygous TAL deficiency are predisposed to cirrhosis, hepatocellular carcinoma (HCC) and acetaminophen (APAP)-induced liver failure. Both mice and humans with complete TAL deficiency accumulate sedoheptulose 7-phosphate (S7P). Previous human studies relied on screening patients with S7P accumulation, thus excluding potentially pathogenic haploinsufficiency. Of note, mice with TAL haploinsufficiency are also predisposed to HCC and APAP-induced liver failure which are preventable with oral N-acetylcysteine (NAC) administration. Based on TALDO1 DNA sequencing, we detected functional TAL deficiency due to novel, heterozygous variations in two of 94 healthy adults and four of 27 subjects with APAP-induced liver failure (P = .022). The functional consequences of these variations were individually validated by site-directed mutagenesis of normal cDNA and loss of activity by recombinant enzyme. All four patients with TAL haplo-insufficiency with APAP-induced liver failure were successfully treated with NAC. We also document two novel variations in two of 15 children with previously unexplained liver cirrhosis. Examination of the National Center for Biotechnology Information databases revealed 274 coding region variations have been documented in 1125 TALDO1 sequences relative to 25 variations in 2870 TKT sequences (P < .0001). These findings suggest an unexpected prevalence and variety of genetic changes in human TALDO1 with relevance for liver injury that may be preventable by treatment with NAC.

Assessment of cows milk-related symptom scoring awareness tool in young Turkish children.

BACKGROUND: The diagnosis of cows milk protein allergy (CMPA) is not always easy. Cow's Milk-related Symptom Score (CoMiSS) has been developed to raise the awareness of CMPA among the primary health-care providers. In this study, we aimed to evaluate the validity of CoMiSS as a diagnostic approach of CMPA in infants in our country. METHODS: Infants with a CoMiSS of more than 12 points were included. An elimination diet was implemented in these infants for 4 weeks, and CoMiSS was reapplied. Infants with a reduction of ≥3 points in CoMiSS were considered responsive to the elimination diet, and an open oral challenge test was performed. Infants with symptom recurrence were diagnosed with CMPA. RESULTS: The study included 168 infants. When they were included in the study, the first CoMiSS score was 13.6 ± 1.9. After the elimination diet, the number of responsive infants was 154 (91.7%). Of the infants, 91 (54.2%) were diagnosed with CMPA with positive challenge. The majority of the patients diagnosed with CMPA presented with gastrointestinal and/or dermatological symptoms (80.3%). Positive family history of allergy was more prevalent in CMPA(+) infants (P < 0.001). The mean atopic dermatitis score was higher in CMPA(+) infants (P = 0.001). Eosinophilia and cows milk-specific IgE (CM-sIgE) positivity were more prevalent in infants with CMPA (P = 0.01 and P < 0.001, respectively). CONCLUSIONS: CoMiSS is a valuable tool to evaluate CMPA in primary care. The presence of multiple symptoms, especially skin involvement, helps to recognise infants with CMPA. Family history and eosinophilia also support the diagnosis of CMPA.

Intestinal Failure and Aberrant Lipid Metabolism in Patients With DGAT1 Deficiency.

BACKGROUND & AIMS: Congenital diarrheal disorders are rare inherited intestinal disorders characterized by intractable, sometimes life-threatening, diarrhea and nutrient malabsorption; some have been associated with mutations in diacylglycerol-acyltransferase 1 (DGAT1), which catalyzes formation of triacylglycerol from diacylglycerol and acyl-CoA. We investigated the mechanisms by which DGAT1 deficiency contributes to intestinal failure using patient-derived organoids. METHODS: We collected blood samples from 10 patients, from 6 unrelated pedigrees, who presented with early-onset severe diarrhea and/or vomiting, hypoalbuminemia, and/or (fatal) protein-losing enteropathy with intestinal failure; we performed next-generation sequencing analysis of DNA from 8 patients. Organoids were generated from duodenal biopsies from 3 patients and 3 healthy individuals (controls). Caco-2 cells and patient-derived dermal fibroblasts were transfected or transduced with vectors that express full-length or mutant forms of DGAT1 or full-length DGAT2. We performed CRISPR/Cas9-guided disruption of DGAT1 in control intestinal organoids. Cells and organoids were analyzed by immunoblot, immunofluorescence, flow cytometry, chromatography, quantitative real-time polymerase chain reaction, and for the activity of caspases 3 and 7. RESULTS: In the 10 patients, we identified 5 bi-allelic loss-of-function mutations in DGAT1. In patient-derived fibroblasts and organoids, the mutations reduced expression of DGAT1 protein and altered triacylglycerol metabolism, resulting in decreased lipid droplet formation after oleic acid addition. Expression of full-length DGAT2 in patient-derived fibroblasts restored formation of lipid droplets. Organoids derived from patients with DGAT1 mutations were more susceptible to lipid-induced cell death than control organoids. CONCLUSIONS: We identified a large cohort of patients with congenital diarrheal disorders with mutations in DGAT1 that reduced expression of its product; dermal fibroblasts and intestinal organoids derived from these patients had altered lipid metabolism and were susceptible to lipid-induced cell death. Expression of full-length wildtype DGAT1 or DGAT2 restored normal lipid metabolism in these cells. These findings indicate the importance of DGAT1 in fat metabolism and lipotoxicity in the intestinal epithelium. A fat-free diet might serve as the first line of therapy for patients with reduced DGAT1 expression. It is important to identify genetic variants associated with congenital diarrheal disorders for proper diagnosis and selection of treatment strategies.

The Frequency of Lysosomal Acid Lipase Deficiency in Children With Unexplained Liver Disease.

OBJECTIVES: Evidence suggests that lysosomal acid lipase deficiency (LAL-D) is often underdiagnosed because symptoms may be nonspecific. We aimed to investigate the prevalence of LAL-D in children with unexplained liver disease and to identify demographic and clinical features with a prospective, multicenter, cross-sectional study. METHODS: Patients (aged 3 months-18 years) who had unexplained transaminase elevation, unexplained hepatomegaly or hepatosplenomegaly, obesity-unrelated liver steatosis, biopsy-proven cryptogenic fibrosis and cirrhosis, or liver transplantation for cryptogenic cirrhosis were enrolled. A Web-based electronic data collection system was used. LAL activity (nmol/punch/h) was measured using the dried blood spot method and classified as LAL-D (<0.02), intermediate (0.02-0.37) or normal (> 0.37). A second dried blood spot sample was obtained from patients with intermediate LAL activity for confirmation of the result. RESULTS: A total of 810 children (median age 5.6 years) from 795 families were enrolled. The reasons for enrollment were unexplained transaminase elevation (62%), unexplained organomegaly (45%), obesity-unrelated liver steatosis (26%), cryptogenic fibrosis and cirrhosis (6%), and liver transplantation for cryptogenic cirrhosis (<1%). LAL activity was normal in 634 (78%) and intermediate in 174 (21%) patients. LAL-D was identified in 2 siblings aged 15 and 6 years born to unrelated parents. Dyslipidemia, liver steatosis, and mild increase in aminotransferases were common features in these patients. Moreover, the 15-year-old patient showed growth failure and microvesicular steatosis, portal inflammation, and bridging fibrosis in the liver biopsy. Based on 795 families, 2 siblings in the same family were identified as LAL-D cases, making the prevalence of LAL-D in this study population, 0.1% (0.125%-0.606%). In the repeated measurement (76/174), LAL activity remained at the intermediate level in 38 patients. CONCLUSIONS: Overall, the frequency of LAL-D patients in this study (0.1%) suggests that LAL-D seems to be rare even in the selected high-risk population.

SCYL1 variants cause a syndrome with low γ-glutamyl-transferase cholestasis, acute liver failure, and neurodegeneration (CALFAN).

PURPOSE: Biallelic mutations in SCYL1 were recently identified as causing a syndromal disorder characterized by peripheral neuropathy, cerebellar atrophy, ataxia, and recurrent episodes of liver failure. The occurrence of SCYL1 deficiency among patients with previously undetermined infantile cholestasis or acute liver failure has not been studied; furthermore, little is known regarding the hepatic phenotype. METHODS: We aimed to identify patients with SCYL1 variants within an exome-sequencing study of individuals with infantile cholestasis or acute liver failure of unknown etiology. Deep clinical and biochemical phenotyping plus analysis of liver biopsies and functional studies on fibroblasts were performed. RESULTS: Seven patients from five families with biallelic SCYL1 variants were identified. The main clinical phenotype was recurrent low γ-glutamyl-transferase (GGT) cholestasis or acute liver failure with onset in infancy and a variable neurological phenotype of later onset (CALFAN syndrome). Liver crises were triggered by febrile infections and were transient, but fibrosis developed. Functional studies emphasize that SCYL1 deficiency is linked to impaired intracellular trafficking. CONCLUSION: SCYL1 deficiency can cause recurrent low-GGT cholestatic liver dysfunction in conjunction with a variable neurological phenotype. Like NBAS deficiency, it is a member of the emerging group of congenital disorders of intracellular trafficking causing hepatopathy.

High-fibre enteral feeding results in improved anthropometrics and favourable gastrointestinal tolerance in malnourished children with growth failure.

AIM: The practical value of using fibre-enriched enteral feeding regimens to rehabilitate malnourished children remains inconclusive. This study determined the usage patterns, gastrointestinal tolerance, anthropometrics and safety of high-fibre enteral feeding in malnourished children with growth failure. METHODS: This Turkish observational study between February 2013 and June 2015 comprised 345 paediatric patients from 17 centres with malnutrition-related growth failure, with a weight and height of <2 SD percentiles for their age. Changes in anthropometrics, gastrointestinal symptoms, defecation habits and safety data relating to adverse events were analysed during the six-month follow-up period. RESULTS: Most subjects (99.7%) were supplemented with enteral feeding. The absolute difference and 95% confidence interval values for the Z scores of height for age, weight for age, weight for height and body mass index for height increased significantly in four months to six months to 0.21 (0.09-0.32), 0.61 (0.51-0.70), 0.81 (0.56-1.06) and 0.70 (0.53-0.86), respectively (p < 0.001 for each). The percentage of patients with normal defecation frequency significantly increased from 70.3% to 92.8% at the four months to six months visit (p = 0.004). Adverse events occurred in 15 (4.3%) of patients. CONCLUSION: Using a six-month high-fibre enteral feeding was associated with favourable outcomes in anthropometrics, appetite, gastrointestinal tolerance and safety in malnourished children.

Multiple Presentations of LRBA Deficiency: a Single-Center Experience.

INTRODUCTION: LPS-responsive beige-like anchor protein (LRBA) deficiency is a primary immunodeficiency categorized as common variable immunodeficiency associated with autoimmune manifestations and inflammatory bowel diseases; however, the clinical spectrum has been extended. Here, we present our cohort of Turkish LRBA-deficient patients from a single center, demonstrating a diversity of clinical manifestations. METHOD: Seven affected individuals from five families were assessed retrospectively in this study. RESULTS: Of the seven patients with LRBA deficiency, four had homozygous, and two had compound heterozygous mutations. One patient remained disease free until the last follow-up (age 17 years). The most common clinical manifestations of the six symptomatic patients were organomegaly (6/6), autoimmunity (6/6), and chronic diarrhea (5/6). Recurrent infectious episodes were observed in three patients. None of the patients had hypogammaglobulinemia at presentation. B cell subpopulation analysis revealed low numbers of switched-memory B cell numbers in two of the four tested patients. During the disease course, three of the patients died, two of them underwent successful hematopoietic stem cell transplantation (HSCT) from matched sibling donors, and one is under abatacept therapy. CONCLUSION: LRBA defects should always be kept in mind as a differential diagnosis for patients with autoimmune disease affecting multiple organs, chronic diarrhea, and organomegalies. In our experience, early HSCT is a life-saving therapeutic strategy.

Diagnosis of celiac disease and applicability of ESPGHAN guidelines in Mediterranean countries: a real life prospective study.

BACKGROUND: We assessed how the diagnosis of Celiac Disease (CD) is made and how the new ESPGHAN guidelines can be applied in children from countries with different resources. METHODS: A real life prospective study was performed in 14 centres of 13 different Mediterranean countries. Participants were asked to apply the usual diagnostic work-up for CD according to their diagnostic facilities. RESULTS: There were 1974 patients enrolled in the study, mean age 4 years, 10 months; 865 male, 1109 female. CD was confirmed in 511 (25.9%) and was unconfirmed in 1391 (70.5%) patients; 14 patients were diagnosed as having CD according to the new ESPGHAN guidelines, 43 patients were classified as having potential CD. In all participating countries the diagnosis of CD relied on histology of duodenal biopsy; in 5 countries, HLA, and in one country endomysial antibodies (EMA) were not available. Symptoms did not add a significant increase to the pre-test probability of serological tests. The positive predictive value of tissue transglutaminase type 2 (tTG) antibodies performed with different kits but all corresponding to those recommended by ESPGHAN was 96.1% (95% CI 94-97.9%) in presence of tTG > 10xULN. In 135 patients with tTG >10xULN, HLA genotyping was performed and in all it was compatible with CD. CONCLUSIONS: The results of our study show that CD diagnosis still relies on intestinal biopsy in the Mediterranean area. New ESPGHAN criteria are not applicable in 5 countries due to lack of resources needed to perform HLA genotyping and, in one country, EMA assay. Further simplification of the new ESPGHAN guidelines might be made according to what preliminarily the present results suggest if confirmed by new prospective studies.

Lipomatous hypertrophy of the interatrial septum in a child with atrial tachycardia.

A 13-year-old girl who had been on home parenteral nutrition for 6 months has been presented with multifocal atrial tachycardia and atrial fibrillation. Echocardiography and multislice computed tomography showed fat accumulation on the interatrial septum. Lipomatous hypertrophy of the interatrial septum has never been reported in children.

Monogenic mutations differentially affect the quantity and quality of T follicular helper cells in patients with human primary immunodeficiencies.

BACKGROUND: Follicular helper T (TFH) cells underpin T cell-dependent humoral immunity and the success of most vaccines. TFH cells also contribute to human immune disorders, such as autoimmunity, immunodeficiency, and malignancy. Understanding the molecular requirements for the generation and function of TFH cells will provide strategies for targeting these cells to modulate their behavior in the setting of these immunologic abnormalities. OBJECTIVE: We sought to determine the signaling pathways and cellular interactions required for the development and function of TFH cells in human subjects. METHODS: Human primary immunodeficiencies (PIDs) resulting from monogenic mutations provide a unique opportunity to assess the requirement for particular molecules in regulating human lymphocyte function. Circulating follicular helper T (cTFH) cell subsets, memory B cells, and serum immunoglobulin levels were quantified and functionally assessed in healthy control subjects, as well as in patients with PIDs resulting from mutations in STAT3, STAT1, TYK2, IL21, IL21R, IL10R, IFNGR1/2, IL12RB1, CD40LG, NEMO, ICOS, or BTK. RESULTS: Loss-of-function (LOF) mutations in STAT3, IL10R, CD40LG, NEMO, ICOS, or BTK reduced cTFH cell frequencies. STAT3 and IL21/R LOF and STAT1 gain-of-function mutations skewed cTFH cell differentiation toward a phenotype characterized by overexpression of IFN-γ and programmed death 1. IFN-γ inhibited cTFH cell function in vitro and in vivo, as corroborated by hypergammaglobulinemia in patients with IFNGR1/2, STAT1, and IL12RB1 LOF mutations. CONCLUSION: Specific mutations affect the quantity and quality of cTFH cells, highlighting the need to assess TFH cells in patients by using multiple criteria, including phenotype and function. Furthermore, IFN-γ functions in vivo to restrain TFH cell-induced B-cell differentiation. These findings shed new light on TFH cell biology and the integrated signaling pathways required for their generation, maintenance, and effector function and explain the compromised humoral immunity seen in patients with some PIDs.

Mesalamine Intolerance in Three Children with Crohn's Disease.

OBJECTIVE: To present the mesalamine-induced acute exacerbation of symptoms and inflammatory markers in children with Crohn's disease (CD). CLINICAL PRESENTATION AND INTERVENTION: Three children who presented with CD had acute exacerbation of colitis symptoms or elevated inflammatory markers when mesalamine was added to treatment while tapering/ceasing steroid treatment. While on steroid treatment, the patients maintained clinical and laboratory remission, but with the initiation of mesalamine treatment, they had abdominal pain and bloody mucoid diarrhoea and/or elevation of white blood cell count, C-reactive protein level and erythrocyte sedimentation rate. Bacterial pathogens were excluded from the urine, throat and blood cultures, parasites with stool examination, viral pathogens with serology. Within 3-7 days after the mesalamine treatment had been stopped, the patients showed improvement of colitis symptoms and normalisation of white blood cell count, C-reactive protein level and erythrocyte sedimentation rate. CONCLUSION: In this study mesalamine mimicked CD relapse in children with CD while tapering or after stopping steroid treatment. Awareness of this side effect of mesalamine could prevent a misdiagnosis of steroid dependency.

Yield of coeliac screening in abdominal pain-associated functional gastrointestinal system disorders.

AIM: Chronic abdominal pain (CAP) in childhood is common and in the majority functional. While CAP is one of the complaints of coeliac disease (CD), whether CAP as a sole complaint is indicative of CD is unclear. Our aim was to evaluate the relationship between CAP and CD. METHODS: The study was conducted on 1047 children (61.1% female, mean age 9.6 ± 4.1 years) with CAP. Patients were evaluated according to the Rome III criteria. Patients with alarm symptoms and conditions known to be associated with CD were excluded. Patients were screened for CD using a rapid tissue transglutaminase (tTG) test; positive cases were tested by tTG ELISA, and duodenal biopsies were obtained if tTG was above the normal limit. RESULTS: Functional dyspepsia (FD), irritable bowel syndrome (IBS) and functional abdominal pain (FAP) were diagnosed in 384 (36.7%), 274 (26.2%) and 389 (37.2%) patients, respectively. In 13 patients, the tTG rapid test was positive; 10 were also positive for tTG by ELISA and histopathological evaluations diagnosed CD in all 10 patients. The overall prevalence of CD was 0.95% (2.2%, 0.5% and 0.5% in patients with IBS, FD and FAP, respectively). The prevalence of CD in patients with IBS was higher than expected but with borderline statistical significance (P = 0.053). CONCLUSIONS: CD is found as common in children with FD and FAP as in the general population. CD was more commonly diagnosed in IBS patients with borderline statistical significance. We suggest that particular attention be paid to children with IBS.

Early-onset inflammatory bowel disease and common variable immunodeficiency-like disease caused by IL-21 deficiency.

BACKGROUND: Alterations of immune homeostasis in the gut can result in development of inflammatory bowel disease (IBD). Recently, Mendelian forms of IBD have been discovered, as exemplified by deficiency of IL-10 or its receptor subunits. In addition, other types of primary immunodeficiency disorders might be associated with intestinal inflammation as one of their leading clinical presentations. OBJECTIVE: We investigated a large consanguineous family with 3 children who presented with early-onset IBD within the first year of life, leading to death in infancy in 2 of them. METHODS: Homozygosity mapping combined with exome sequencing was performed to identify the molecular cause of the disorder. Functional experiments were performed to assess the effect of IL-21 on the immune system. RESULTS: A homozygous mutation in IL21 was discovered that showed perfect segregation with the disease. Deficiency of IL-21 resulted in reduced numbers of circulating CD19(+) B cells, including IgM(+) naive and class-switched IgG memory B cells, with a concomitant increase in transitional B-cell numbers. In vitro assays demonstrated that mutant IL-21(Leu49Pro) did not induce signal transducer and activator of transcription 3 phosphorylation and immunoglobulin class-switch recombination. CONCLUSION: Our study uncovers IL-21 deficiency as a novel cause of early-onset IBD in human subjects accompanied by defects in B-cell development similar to those found in patients with common variable immunodeficiency. IBD might mask an underlying primary immunodeficiency, as illustrated here with IL-21 deficiency.

Gastric carcinoid tumor in a 14-year old girl.

Gastric carcinoid tumors (GCT) are rare lesions that constitute 2.6-8.7% of all gastrointestinal carcinoids, mostly affect middle-aged females but the incidence in children is unknown. We present a 14-year-old girl, with GCT. She was treated with recombinant human growth hormone (GH) for complete GH deficiency, and endoscopy was performed to identify iron-deficiency anemia. Upper gastrointestinal endoscopy revealed a gastric polyp, and biopsies were compatible with GCT.

A point-of-care test for facing the burden of undiagnosed celiac disease in the Mediterranean area: a pragmatic design study.

BACKGROUND: We aimed at assessing the factors that can influence results of the dissemination of an already validated, new generation commercial Point-of-Care Test (POCT) for detecting celiac disease (CD), in the Mediterranean area, when used in settings where it was designed to be administered, especially in countries with poor resources. METHODS: Pragmatic study design. Family pediatricians at their offices in Italy, nurses and pediatricians in Slovenia and Turkey at pediatricians', schools and university primary care centers looked for CD in 3,559 (1-14 yrs), 1,480 (14-23 yrs) and 771 (1-18 yrs) asymptomatic subjects, respectively. A new generation POCT detecting IgA-tissue antitransglutaminase antibodies and IgA deficiency in a finger-tip blood drop was used. Subjects who tested positive and those suspected of having CD were referred to a Celiac Centre to undergo further investigations in order to confirm CD diagnosis. POCT Positive Predictive Value (PPV) at tertiary care (with Negative Predictive Value) and in primary care settings, and POCT and CD rates per thousand in primary care were estimated. RESULTS: At tertiary care setting, PPV of the POCT and 95% CI were 89.5 (81.3-94.3) and 90 (56-98.5) with Negative Predictive Value 98.5 (94.2-99.6) and 98.7% (92-99.8) in children and adults, respectively. In primary care settings of different countries where POCT was performed by a different number of personnel, PPV ranged from 16 to 33% and the CD and POCT rates per thousand ranged from 4.77 to 1.3 and from 31.18 to 2.59, respectively. CONCLUSIONS: Interpretation of POCT results by different personnel may influence the performance of POC but dissemination of POCT is an urgent priority to be implemented among people of countries with limited resources, such as rural populations and school children.