Prediction of thiopurine failure in pediatric Crohn's disease: pediatric IBD Porto group of ESPGHAN.

BACKGROUND: Maintaining of remission early in the disease course of Crohn's disease (CD) is essential and has major impact on the future prognosis. This study aimed to identify baseline predictors to develop model allowing stratification of patients who will not benefit from long-term azathioprine (AZA) treatment and will require more intensive therapy. METHODS: This study was designed to develop clinical prediction rule using retrospective data analysis of pediatric CD patients included in prospective inception cohort. Clinical relapse was defined as necessity of re-induction of remission. Sequence of Cox models was fitted to predict risk of relapse. RESULTS: Out of 1190 CD patients from 13 European centers, 441 were included, 50.3% patients did not experience clinical relapse within 2 years of AZA treatment initiation. Median time to relapse was 2.11 (CI 1.59-2.46) years. Of all the tested parameters available at diagnosis, six were significant in multivariate analyses: C-reactive protein (p = 0.038), body mass index Z-score >0.8 SD (p = 0.002), abnormal sigmoid imaging (p = 0.039), abnormal esophageal endoscopy (p = 0.005), ileocolonic localization (p = 0.023), AZA dose in specific age category (p = 0.031). CONCLUSIONS: Although the possibility of predicting relapse on AZA treatment appears limited, we developed predictive model based on six baseline parameters potentially helpful in clinical decision. IMPACT: The possibility of predicting relapse on AZA treatment appears to be possible but limited. We identified six independent predictors available at diagnosis of early AZA/6-MP treatment failure in pediatric CD patients. Using combination of these factors, a model applicable to clinical practice was created. A web-based tool, allowing estimation of individual relapse risk in pediatric CD patients on a particular therapeutic regimen, has been developed.

Intensive Lifestyle Management Improves Steatosis and Fibrosis in Pediatric Nonalcoholic Fatty Liver Disease.

BACKGROUND & AIMS: Childhood obesity, with associated comorbidities such as nonalcoholic fatty liver disease (NAFLD), is an increasing global health problem. Although lifestyle management is the mainstay of treatment, its efficacy on liver fibrosis has not yet been established. METHODS: Children and adolescents admitted for severe obesity at a tertiary center (Zeepreventorium, De Haan, Belgium) were enrolled in this prospective study. Intensive lifestyle therapy encompassed caloric restriction, physical activity, education on a healthy lifestyle, and psychosocial support. At baseline, 6 months, and 12 months, liver ultrasound and transient elastography with controlled attenuation parameter were performed to assess liver steatosis and fibrosis. RESULTS: A total of 204 patients (median age, 14.0 y; body mass index Z-score, +2.8) were evaluated at admission. NAFLD on ultrasound was present in 71.1%, whereas 68.6% had controlled attenuation parameter values of 248 dB/m or greater. A total of 32.8% of patients had at least F2 fibrosis, including 10.3% with transient elastography of 9 kPa or greater. After 6 months, the median body weight loss was 16.0% in the 167 patients evaluated. Fibrosis improved in 75.0% (P < .001). Baseline severity of liver fibrosis and steatosis were predictors of fibrosis resolution. Seventy-nine patients had reached the 1-year time point. The improvements were sustained because fibrosis regressed at least 1 stage in all patients with baseline fibrosis. Fasting serum alanine aminotransferase and homeostasis model assessment of insulin resistance decreased significantly over the 1-year period (P < .001). CONCLUSIONS: NAFLD and associated fibrosis are highly prevalent in children and adolescents with severe obesity. An intensive multidisciplinary lifestyle management program that causes significant weight loss not only improves liver steatosis, but also fibrosis.

Non-invasive assessment of liver abnormalities in pediatric Fontan patients.

Liver abnormalities are well known among long-term survivors of Fontan palliation, which remains the definite surgery for complex congenital heart disease and single ventricle physiology. Pediatric data however are scarce. We assessed the prevalence and degree of liver abnormalities in pediatric Fontan patients through non-invasive investigations suitable for longitudinal follow-up. Thirty-five patients with a median age of 11.8 years (5.2-16.6) and median time since Fontan of 6 years (1.17-13.83) were studied. Each child underwent a blood test, liver Doppler ultrasound (US), and transient elastography (TE). Healthy children were used as controls for TE measurement. AST, ALT, γGT, and direct bilirubin were abnormal in respectively 12 (34%), 5 (14%), 24 (69%), and 7 (20%) patients, while platelet count was decreased in 7 (20%). Splenomegaly was present in 7 (20%) patients. Portal vein mean flow velocity was < 15 cm/s in 19 (54%) patients indicative of portal hypertension. Twenty-two patients (63%) showed inferior vena cava collapsibility index values below 17%, indicating venous congestion. Hepatic artery and superior mesenteric artery resistance index were inversely correlated with time post Fontan (p < 0.05). TE values in Fontan patients were significantly higher than controls, with a median of 12.6 versus 4.6 kPa (p < 0.001) and were already increased shortly after Fontan completion. Conclusion: Liver abnormalities are frequently observed in pediatric Fontan patients. The non-invasive investigations used were not able to confirm liver fibrosis or differentiate hepatic congestion from fibrosis. Based on our findings, we propose a prospective screening protocol with serial measurements of laboratory, (Doppler) US, and TE parameters. What is Known: • Hepatic dysfunction is a well-known consequence of the Fontan circulation. • The natural history of Fontan-associated liver disease in the pediatric age group remains unclear. What is New: • Liver abnormalities are frequently observed in pediatric Fontan patients; however, differentiating liver fibrosis and hepatic congestion with non-invasive investigations remains challenging. Sonographic Doppler measurements may improve our insight in both Fontan-associated liver disease development and the functioning of the Fontan circulation. • A prospective screening protocol is proposed to improve our ability to detect Fontan-associated liver disease early on and understand its natural history.

Two cases of DCDC2-related neonatal sclerosing cholangitis with developmental delay and literature review.

Ciliopathies are a group of clinical and molecular heterogeneous conditions with pleiotropic manifestations affecting the central nervous system, renal, liver, skeletal, and ocular systems. Biallelic pathogenic variants in DCDC2 cause a ciliopathy primarily presenting with neonatal sclerosing cholangitis (NSC). Pathogenic variants in DCDC2 have further been reported in the context of nephronophthisis and non-syndromic recessive deafness. Polymorphisms in DCDC2 have also been associated with dyslexia and DCDC2 has a role in neuronal development. We report on two unrelated patients with DCDC2-related NSC with additional central nervous system impairment manifesting as microcephaly, global developmental delay, and axial hypotonia. Histological findings of our patients can mimic biliary atresia or congenital hepatic fibrosis. We further show that transmission electron microscopy in patients with NSC does not always show absence of primary cilia. Hence patients with DCDC2 pathogenic variants should also undergo an evaluation of neuromotor development. Review of all reported patients further reveals a risk for supra-aortic arterial aneurysms.

Successful liver transplantation in hyperornithinemia-hyperammonemia-homocitrullinuria syndrome: Case report.

BACKGROUND: HHH syndrome is a rare autosomal recessive disorder of the urea cycle, caused by a deficient mitochondrial ornithine transporter. We report the first successful liver transplantation in HHH syndrome performed in a seven-year-old boy. The patient presented at 4 weeks of age with hyperammonemic coma. The plasma amino acid profile was suggestive of HHH syndrome, and the diagnosis was confirmed when sequencing of the SLC25A15 gene identified two mutations p.R275Q and p.A76D. Although immediate intervention resulted in normalization of plasma ammonia levels within 24 hours, he developed cerebral edema, coma, convulsions, and subsequent neurological sequelae. Metabolic control was difficult requiring severe protein restriction and continued treatment with sodium benzoate and L-arginine. Despite substantial developmental delay, he was referred to our center for liver transplantation because of poor metabolic control. Following cadaveric split liver transplantation, there was complete normalization of his plasma ammonia and plasma amino acid levels under a normal protein-containing diet. This excellent metabolic control was associated with a markedly improved general condition, mood and behavior, and small developmental achievements. Twelve years after liver transplantation, the patient has a stable cognitive impairment without progression of spastic diplegia. CONCLUSION: This first case of liver transplantation in HHH syndrome demonstrates that this procedure is a therapeutic option for HHH patients with difficult metabolic control.

Autoantibodies and Donor-specific Antibodies are Associated With Graft Dysfunction in Pediatric Liver Transplantation.

OBJECTIVES: Autoantibodies (AAb) and donor-specific HLA antibodies (DSA) are frequently present in pediatric liver transplant (LT) recipients. Their clinical significance remains incompletely understood. We aimed to investigate the prevalence of serum AAb and DSA in pediatric LT recipients and its correlation with patient characteristics and histological and biochemical parameters. METHODS: We retrospectively reviewed the data from 62 pediatric LT patients in follow-up at Ghent University Hospital between January 2007 and February 2018. Blood samples with AAb measurement were taken systematically, liver biopsies (LB) were performed on clinical indication. RESULTS: AAb were detected in 27 (43.3%) patients, with antinuclear antibodies (ANA) being the most frequently (24%) encountered AAb. There was an association between AAb positivity and female gender (P = 0,032) and deceased donor LT (P = 0,006). Patients with positive AAb underwent a higher number of LB during their follow-up (P < 0,001), and an association was found with the presence of nonspecific histologic alterations (P = 0,032) in the absence of de novo autoimmune hepatitis. Positive AAb were also associated with higher alkaline phosphatase (P < 0,001), ALT (P < 0,001), AST (P < 0,001), γ-GT (P = 0,001), IgG (P = 0,011) and lower albumin (P = 0,029). Fourteen out of 50 (28%) patients were DSA-positive, mostly anti-HLA class II. DSA positivity was associated with T-cell-mediated rejection (P = 0,019), higher total (P = 0,033), and direct (P = 0,012) bilirubin and γ-GT (P < 0,001). CONCLUSIONS: The presence of AAb and DSA is associated with histological and biochemical parameters of graft dysfunction. Larger prospective studies are warranted to investigate the causal relationships between AAb and DSA development and outcome parameters post pediatric LT.

The effect of an intensive residential rehabilitation program on body composition in patients with cystic fibrosis.

The pulmonary function of patients with cystic fibrosis (CF) is associated with nutritional status not only expressed as body mass index (BMI) but also as fat-free mass index (FFMI). This study evaluated the effect of a residential rehabilitation program on nutritional status (BMI, FFMI). The rehabilitation program provided supervised respiratory and nutritional treatment and daily physical activity for 3 weeks (median stay 20 (19-25) days). At the start and the end of the program, weight, height, pulmonary function, and body composition using dual-energy X-ray absorptiometry were prospectively collected. Supervised weighed food records were obtained, and physical activity intensity was measured using a SenseWear Pro3 Armband. CF-related complications were collected from the patient. Thirty-four patients (21 males, median age 18 years old (12-27)) were included. The diet contained a median of 30 EN% fat, 16 EN% protein, and 52 EN% of carbohydrates. A significant median weight gain (+1.45 kg (0.58; 2.6) (p < 0.0001) and a significant increase in BMI (+0.24 kg/m2 (0.11; 0.38)) (p < 0.0001), FFMI (+0.26 kg/m2 (0.01; 0.55)) (p < 0.0001), and FMI (+0.19 kg/m2 (0.04; 0.41)) (p < 0.0001) were obtained.Conclusion: A short rehabilitation program in individuals with CF between 6 and 40 years old is able to improve nutritional status and body composition.Trial registration: NCT04527796 What is Known: • Fat-free mass depletion is frequently present in CF. • In CF pulmonary function is associated with nutritional status measured as body mass index but also fat-free mass index. What is New: • Nutritional status and body composition improve significantly after a short-term rehabilitation program. • The rehabilitation program was able to improve nutritional outcome even with a diet containing less fat than currently advised in the guidelines.

Primum non nocere: lingual frenotomy for breastfeeding problems, not as innocent as generally accepted.

The frenotomy or surgical release of the lingual frenulum is performed with increasing frequency. Restricted tongue mobility, ankyloglossia, is the main indication for this procedure. This clinical diagnosis is often used as synonym for tongue-tie which is blamed for many feeding difficulties resulting in an increase in performed frenotomies. Until recently, little was known about the anatomical structure and normal variation of the tongue-tie. Different grading systems have been developed. Some are exclusively based on appearance of the tongue-tie; others also include functional elements. There is, however, no established relation between the tongue-tie score and the observed feeding problems or outcomes following frenotomy. Therefore, caution is warranted before submitting babies to this procedure.Conclusion: This narrative review aims to give an overview of current knowledge and concerns regarding the tongue-tie, which need to be considered before referral for a frenotomy. What is Known: • The presence of a tongue-tie is associated with a higher frequency of breastfeeding problems. • Hence, frenotomy is advocated and increasingly performed in infants with breastfeeding problems. Current tongue-tie classifications do not allow to predict breastfeeding problems. What is New: • New anatomy insights caution for possible complications resulting from this seemingly innocent practice of frenotomy. • Frenotomy should only be performed after multidisciplinary evaluation of feeding problems, following exclusion and remediation of other causative factors.

Infliximab in young paediatric IBD patients: it is all about the dosing.

Infliximab (IFX) is administered intravenously using weight-based dosing (5 mg/kg) in inflammatory bowel disease (IBD) patients. Our hypothesis is that especially young children need a more intensive treatment regimen than the current weight-based dose administration. We aimed to assess IFX pharmacokinetics (PK), based on existing therapeutic drug monitoring (TDM) data in IBD patients < 10 years. TDM data were collected retrospectively in 14 centres. Children treated with IFX were included if IFX was started as IBD treatment at age < 10 years (young patients, YP) and PK data were available. Older IBD patients aged 10-18 years were used as controls (older patients, OP). Two hundred and fifteen paediatric inflammatory bowel disease (PIBD) patients were eligible for the study (110 < 10 year; 105 ≥ 10 years). Median age was 8.3 years (IQR 6.9-8.9) in YP compared with 14.3 years (IQR 12.8-15.6) in OP at the start of IFX. At the start of maintenance treatment, 72% of YP had trough levels below therapeutic range (< 5.4 µg/mL). After 1 year of scheduled IFX maintenance treatment, YP required a significantly higher dose per 8 weeks compared with OP (YP; 9.0 mg/kg (IQR 5.0-12.9) vs. OP; 5.5 mg/kg (IQR 5.0-9.3); p < 0.001). The chance to develop antibodies to infliximab was relatively lower in OP than YP (0.329 (95% CI - 1.2 to - 1.01); p < 0.001), while the overall duration of response to IFX was not significantly different (after 2 years 53% (n = 29) in YP vs. 58% (n = 45) in OP; p = 0.56).Conclusion: Intensification of the induction scheme is suggested for PIBD patients aged < 10 years. What is Known? •Infliximab trough levels of paediatric IBD patients are influenced by several factors as dosing scheme, antibodies and inflammatory markers. •In 4.5-30% of the paediatric IBD patients, infliximab treatment was stopped within the first year. What is New? •The majority of young PIBD (< 10 years) have inadequate IFX trough levels at the start of maintenance treatment. •Young PIBD patients (< 10 years) were in need of a more intensive treatment regimen compared with older paediatric patients during 1 year of IFX treatment. •The chance to develop antibodies to infliximab was relatively higher in young PIBD patients (< 10 years).

Intra-patient variability in tacrolimus exposure in pediatric liver transplant recipients: Evolution, risk factors, and impact on patient outcomes.

BACKGROUND: This study aims to investigate the evolution and factors associated with TAC IPV and its impact on patient outcomes in pediatric LT recipients. METHODS: This is a retrospective study including 41 children. The TAC IPV was expressed as the coefficient of variation and was calculated for years 1-5 following LT. The number of missed clinic appointments was used as a surrogate marker for therapy adherence. RESULTS: We identified a decrease in the TAC IPV during the first 3 years after LT (P < 0.01). Serum albumin in the first year (P = 0.03), hematocrit (P = 0.02) and total bilirubin (P = 0.04) in the third year, and therapy adherence (P < 0.01) in the fifth year were associated with TAC IPV. High TAC IPV was associated with biopsy-proven acute allograft rejection (P = 0.04) and the need for biopsy during the first year (P = 0.02). There was a borderline association between TAC IPV and donor-specific antibodies (P = 0.08) and CMV viremia (P = 0.07). High TAC IPV was a predictor of need for liver biopsy and AR with an odds ratio of 1.04 (95% CI 1.0-1.1; P = 0.03) and 1.04 (95% CI 1.0-1.1; P = 0.05), respectively. CONCLUSIONS: Our results highlight the impact of biological factors on TAC IPV during the early LT follow-up and later also therapy adherence. High TAC IPV may be associated with adverse patient outcomes.

Risk factors and impact of allergic bronchopulmonary aspergillosis in Pseudomonas aeruginosa-negative CF patients.

BACKGROUND: Allergic bronchopulmonary aspergillosis (ABPA) is a major complication in cystic fibrosis (CF) patients. Risk factors for ABPA and clinical deterioration in CF patients, negative for Pseudomonas aeruginosa (Pa), were explored. METHODS: We performed a retrospective case-control study in 73 Pa-negative patients. Each patient was matched with 2 controls for age, gender, pancreas sufficiency, DeltaF508 mutation (homozygous or heterozygous), and Pa colonization. RESULTS: Median FEV1 at the year of diagnosis (index year) was significantly lower in patients with ABPA. The median of cumulative values of FEV1 and FVC before the index year was not significantly different. After the index year, the median of cumulative data for FEV1 and FVC was significantly lower; there were significantly more hospitalization days and more IV antibiotic days compared to controls. Comparing pre- and post-index year data in patients with ABPA, significantly more hospitalization days and more IV antibiotic days were observed after the index year. During the period preceding the index year, significantly more ABPA patients were treated with rhDNase and inhaled corticosteroids. CONCLUSIONS: Bronchial damage cannot be considered as a facilitating factor for ABPA. ABPA causes a significant increase in bronchial damage. In patients with ABPA, further bronchial damage can be controlled by an increase in hospitalization days and use of IV antibiotics. rhDNase and inhaled corticosteroids were associated with the development of ABPA.

Nutritional Considerations in Pediatric Pancreatitis: A Position Paper from the NASPGHAN Pancreas Committee and ESPGHAN Cystic Fibrosis/Pancreas Working Group.

OBJECTIVES: Wide variations exist in how physicians manage the nutritional aspects of children affected by acute pancreatitis (AP), acute recurrent pancreatitis (ARP), and chronic (CP) pancreatitis. Better consensus for optimal management is needed. METHODS: This consensus statement on nutrition in pediatric pancreatic diseases was developed through a joint ESPGHAN-NASPGHAN working group that performed an evidence-based search of the literature on nutrition in AP, ARP, and CP with a focus on pediatrics. The literature was summarized, quality of evidence reviewed, and expert recommendations developed. The authorship met to discuss the evidence and statements. Voting on recommendations occurred over 2 rounds based on feedback. A consensus of at least 75% was required to approve a recommendation. Areas requiring further research were identified. RESULTS AND DISCUSSION: The literature on nutrition in pediatric pancreatitis is limited. Children with mild AP benefit from starting an early nutritional regimen in the course of the attack. Early nutrition should be attempted in severe AP when possible; enteral nutrition is preferred over parenteral nutrition. Children with ARP are likely to tolerate and benefit from a regular diet. Children with CP need ongoing assessment for growth and nutritional deficiencies, exocrine and endocrine insufficiencies. CONCLUSIONS: This document presents the first authoritative recommendations on nutritional considerations in pediatric pancreatitis. Future research should address the gaps in knowledge particularly relating to optimal nutrition for AP in children, role of diet or dietary supplements on recurrent attacks of pancreatitis and pain episodes, monitoring practices to detect early growth and nutritional deficiencies in CP and identifying risk factors that predispose children to these deficiencies.

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.

Proposal for An Algorithm for Screening for Undernutrition in Hospitalized Children.

The prevalence of disease-related undernutrition in hospitalized children has not decreased significantly in the last decades in Europe. A recent large multicentric European study reported a percentage of underweight children ranging across countries from 4.0% to 9.3%. Nutritional screening has been put forward as a strategy to detect and prevent undernutrition in hospitalized children. It allows timely implementation of adequate nutritional support and prevents further nutritional deterioration of hospitalized children. In this article, a hands-on practical guideline for the implementation of a nutritional care program in hospitalized children is provided. The difference between nutritional status (anthropometry with or without additional technical investigations) at admission and nutritional risk (the risk of the need for a nutritional intervention or the risk for nutritional deterioration during hospital stay) is the focus of this article. Based on the quality control circle principle of Deming, a nutritional care algorithm, with detailed instructions specific for the pediatric population was developed and implementation in daily practice is proposed. Further research is required to prove the applicability and the merit of this algorithm. It can, however, serve as a basis to provide European or even wider guidelines.

Paediatric Crohn Disease: Disease Activity and Growth in the BELCRO Cohort After 3 Years Follow-up.

OBJECTIVE: The Belgian registry for paediatric Crohn disease (BELCRO) cohort is a prospective, multicentre registry for newly diagnosed paediatric patients with Crohn disease (CD) (<18 years) recruited from 2008 to 2010 to identify predictive factors for disease activity and growth. METHODS: Data from the BELCRO database were evaluated at diagnosis, 24 and 36 months follow-up. RESULTS: At month 36 (M36), data were available on 84 of the 98 patients included at diagnosis. Disease activity evolved as follows: inactive 5% to 70%, mild 19% to 24%, and moderate to severe 76% to 6%. None of the variables such as age, sex, diagnostic delay, type of treatment, disease location, disease activity at diagnosis, and growth were associated with disease activity at M36. Paediatricians studied significantly less patients with active disease at M36 compared with adult physicians. Sixty percent of the patients had biologicals as part of their treatment at M36. Adult gastroenterologists initiated biologicals significantly earlier. They were the only factor determining biologicals' initiation, not disease location or disease severity at diagnosis. Median body mass index (BMI) z score evolved from -0.97 (range -5.5-2.1) to 0.11 (range -3.4-2) and median height z score from -0.15 (range -3.4-1.6) to 0.12 (range -2.3-2.3) at M36. None of the variables mentioned above influenced growth over time. CONCLUSIONS: Present treatment strategies lead to good disease control in the BELCRO cohort after 3 years. Logistic regression analysis did not show any influence of disease location or present treatment strategy on disease activity and growth, but patients under paediatric care had significantly less severe disease at M36.

Development and validation of a spina bifida-specific pediatric quality of life questionnaire: the Spina Bifida Pediatric Questionnaire, SBPQ.

PURPOSE: Based on existing questionnaires and patient interview, a health-related quality of life (HRQoL) questionnaire in spina bifida (SB) children is created and validated, the Spina Bifida Pediatric Questionnaire (SBPQ). METHODS: SB patients from the SB reference centre Ghent University Hospital, Belgium, with mental ability between 6 and 18 years old and their parents were asked to participate in the study, together with a control group. RESULTS: Thirty-nine patients and parents answered the questionnaire once, 20 patients and their parents the test-retest. Thirty-five controls answered the questionnaire once, 34 controls and their parents the test-retest. The final questionnaire was retained when 3 consecutive patients approved all items. Visual clues were added for children with a mental ability below 10 years of age. The test-retest showed a good to excellent agreement for child self-report in 5 domains (not for social functioning), for parent proxy report in all domains (6), for control self-report in 4 domains (not for domain home) and for control parent proxy report in all domains (5). Internal consistency reliability was good in child self-report and in parent proxy report, except for physical functioning in child self-report. There was parent-child agreement for 4 out of 6 domains. Regarding social and emotional functioning, QoL was rated lower by parents than by children themselves. CONCLUSION: A SB HRQoL questionnaire was developed and validated. Because of visual aid, this questionnaire can be used by both young children and adolescents.

Proteolysis is a confounding factor in the interpretation of faecal calprotectin.

BACKGROUND: Calprotectin is a 36 kDa calcium and zinc binding protein. An increased level of calprotectin points towards inflammatory bowel disease. However, the biomarker calprotectin shows 14 potential cleavages sites for trypsin. Next to trypsin, also the presence of its inhibitor α1-antitrypsin after a gastrointestinal bleeding may affect calprotectin testing. In this study, effects of trypsin and α1-antitrypsin as potential confounders for faecal calprotectin testing are investigated. METHODS: An in vitro model was created. As calprotectin source, leukocytes were isolated and subsequently lysed (1% Triton X-100) and diluted in faecal matrix. Trypsin digestion was carried out by adding trypsin. Incubation occurred for 24 h or 48 h (37 °C). To study the influence of α1-antitrypsin on trypsin, the same experiment was repeated after adding serum containing α1-antitrypsin. RESULTS: In vitro experiments enabled monitoring of the faecal calprotectin digestion, leading to loss of immunoreactivity. Trypsin activity was a potential confounder in the interpretation of calprotectin, in particular for proximal lesions, where exposure of calprotectin to trypsin is prolonged. Relative calprotectin loss was proportional to the amount of trypsin. Decrease of calprotectin was more pronounced after 48 h of incubation in comparison to 24 h of incubation. Analogue experiments also showed stable calprotectin values after adding α1-antitrypsin. CONCLUSIONS: Transit time, trypsin activity and addition of blood as a source of α1-antitrypsin may be regarded as potential confounders in the interpretation of calprotectin results. Age-related cut-off values depending on the anatomical localisation of the lesions could improve the diagnostic efficiency of calprotectin testing.

Faecal leukocyte esterase activity is an alternative biomarker in inflammatory bowel disease.

BACKGROUND: Leukocyte cytosolic proteins (e.g., calprotectin) are emerging biomarkers for inflammatory bowel disease. Leukocyte aryl esterase activity has been commonly used for sensitive detection of leukocytes in human body fluids such as urine. Urine test strip results are generally reported in categories. As automated strip readers allow quantitative data to be reported, sensitive quantitative detection of leukocytes in body fluids has become possible. Here, we explored the use of leukocyte esterase as a potential alternative faecal biomarker for inflammatory bowel disease. METHODS: We evaluated leukocyte esterase activity in faecal extracts and compared Cobas u 411 (Roche) quantitative reflectance data with calprotectin concentration for 107 routine samples. Stability of leukocyte esterase for trypsin digestion was carried out by adding trypsin to the extract. Incubation occurred at 37 °C for 24 h or 48 h. RESULTS: Reproducibility of the reflectance signal was good (within-run imprecision: 6.1%; between-run imprecision: 6.2%). Results were linear in the range 103-106 WBC/100 mg faeces. The lower limit of detection was 4 WBC/µL and the lower limit of quantification was 5 WBC/µL. Stability of LE activity in stool and faecal matrix was good. An adequate correlation was obtained between leukocyte esterase activity and the faecal calprotectin concentration: log(y)=4.28+0.29log(x). In vitro experiments monitored the digestion of leukocyte esterase and faecal calprotectin. Leukocyte esterase activity was significantly less affected by trypsin activity than calprotectin immunoreactivity. CONCLUSIONS: Quantitative leukocyte esterase activity of faecal extracts provides information about the leukocyte count in the gut lumen. Leukocyte esterase is a promising and affordable alternative biomarker for monitoring inflammatory bowel disease.

The course of anaemia in children and adolescents with Crohn's disease included in a prospective registry.

AIM: The aim of this study is to determine the prevalence and evolution of anaemia in prospectively followed children and adolescents diagnosed with Crohn's disease (CD). METHODS: The BELCRO registry (inclusion May 2008-April 2010), describing current clinical treatment practice of children diagnosed with CD, provided data on age, height, body mass index (BMI), paediatric Crohn's disease activity index (PCDAI), therapy and haemoglobin (Hb) at diagnosis 12 and 24 months follow-up. Anaemia was defined as Hb < -2 sd, while severe anaemia was defined as Hb < -4 sd. Patients were classified as child ≤13 and adolescent >13 years of age. RESULT: Ninety-six were included, 13 dropped out due to insufficient Hb data (37 females/46 males; median age 13.3 years, range 2.2-17.8 years). At diagnosis, the median Hb sd was -2.66 (-8.4; 1.07) and was correlated with the PCDAI (p = 0.013). At diagnosis, 51/83 (61%) were anaemic and all had active disease. Hb z-score significantly improved (p < 0.0001) but 26/68 (38%) remained anaemic at 12 months and 29/76 (38%) at 24 months of follow-up. The correlation to the PCDAI disappeared. At 24 months, children were more likely to be anaemic. There was no difference in iron dose nor duration of iron supplements between children and adolescents. Iron treatment was more readily given to patients presenting with anaemia. Hb did not differ between patients with (n = 28) or without iron supplements. Half of the patients with persisting anaemia were given iron supplements, of which, only three were given intravenously. CONCLUSION: Anaemia remains an important extra-intestinal manifestation of CD in children. Physicians, lacking optimal treatment strategies, undertreat their patients.

Clinical zinc deficiency as early presentation of Wilson disease.

Wilson disease is a rare autosomal recessive disorder of the copper metabolism caused by homozygous or compound heterozygous mutations in the ATP-ase Cu(2+) transporting polypeptide (ATP7B) gene. The copper accumulation in different organs leads to the suspicion of Wilson disease. We describe a child with clinical zinc deficiency as presenting symptom of Wilson disease, which was confirmed by 2 mutations within the ATP7B gene and an increased copper excretion.