Long-term evaluation of faecal calprotectin levels in a European cohort of children with cystic fibrosis.

OBJECTIVE: Intestinal inflammation with contradictory data on faecal calprotectin (fCP) levels is documented in patients with cystic fibrosis (CF). The aim of this study was to longitudinally evaluate fCP in a cohort of children with CF and their relationship with clinical variables. DESIGN: Prospective observational study to assess evolution of fCP levels, primary aimed at improving fat absorption. Along 1.5 years of follow-up (November 2016-May 2018) with four study visits pertaining to a pilot study (two of four) and to a clinical trial (two of four), the study outcomes were measured. SETTING: Six European CF centres in the context of MyCyFAPP Project. SUBJECTS: Children with CF and pancreatic insufficiency (2-18 years old). MAIN OUTCOME MEASUREMENTS: fCP levels, pulmonary function (percentage of forced expiratory volume in 1 s (FEV1%)) and coefficient of fat absorption (CFA). Additionally, in the last two visits, gastrointestinal (GI) symptoms were evaluated through the PedsQL-GI Questionnaire. Linear mixed regression models were applied to assess association between fCP and FEV1, CFA and GI symptoms. RESULTS: Twenty-nine children with CF and pancreatic insufficiency were included. fCP levels were inversely associated with total modified specific PedsQL-GI score (p=0.04) and positively associated with diarrhoea (p=0.03), but not with CFA. Along the four study visits, fCP significantly increased (from 62 to 256 µg/g) and pulmonary function decreased (from 97% to 87%), with a significant inverse association between the two study outcomes (p<0.001). CONCLUSIONS: In children with CF, fCP levels are inversely associated with pulmonary function and thus the specificity of fCP as a marker of intestinal inflammation in paediatric patients with CF warrants further investigation.

Gastrointestinal Biomarkers and Their Association with Feeding in the First Five Days of Pediatric Critical Illness.

OBJECTIVES: Predicting the patients' tolerance to enteral nutrition (EN) would help clinicians optimize individual nutritional intake. This study investigated the course of several gastrointestinal (GI) biomarkers and their association with EN advancement (ENA) longitudinally during pediatric intensive care unit (PICU) admission. METHODS: This is a secondary analysis of the Early versus Late Parenteral Nutrition in the Pediatric Intensive Care Unit randomized controlled trial. EN was started early and increased gradually. The cholecystokinin (CCK), leptin, glucagon, intestinal fatty acid-binding protein 2 (I-FABP2), and citrulline plasma concentrations were measured upon PICU admission, day 3 and day 5. ENA was defined as kcal EN provided as % of predicted resting energy expenditure. The course of the biomarkers and ENA was examined in patients with samples on all time points using Friedman and Wilcoxon signed-rank tests. The association of ENA with the biomarkers was examined using a 2-part mixed-effects model with data of the complete population, adjusted for possible confounders. RESULTS: For 172 patients, median age 8.6 years (first quartile; third quartile: 4.2; 13.4), samples were available, of which 55 had samples on all time points. The median ENA was 0 (0; 0) on admission, 14.5 (0.0; 43.8) on day 3, and 28.0 (7.6; 94.8) on day 5. During PICU stay, CCK and I-FABP2 concentrations decreased significantly, whereas glucagon concentrations increased significantly, and leptin and citrulline remained stable. None of the biomarkers was longitudinally associated with ENA. CONCLUSIONS: Based on the current evidence, CCK, leptin, glucagon, I-FABP2, and citrulline appear to have no added value in predicting ENA in the first 5 days of pediatric critical illness.

Children with Intestinal Failure are at Risk for Psychopathology and Trauma.

OBJECTIVES: The objective of this study is to assess the psychopathology and medical traumatic stress in children with intestinal failure (IF) and identify associated risk factors. METHODS: Two-center study, performed from September 2019 until April 2022 (partly during COVID-19 pandemic), including children (1.5-17 years) with IF, dependent on parenteral nutrition (PN) or weaned off PN, treated by a multidisciplinary IF-team. Psychopathology in children was evaluated with a semi-structured interview assessing psychiatric classifications and validated questionnaires assessing emotional (internalizing) and behavioral (externalizing) problems. Medical traumatic stress was assessed with a validated questionnaire. Problem scores were compared with normative data. Associations between clinical characteristics and outcomes were analyzed with linear regression analyses. RESULTS: Forty-one (of 111 eligible) children were included [median age 8.9 years (interquartile range, IQR 5.5-11.8), 54% female, 73% born preterm]. Median PN-duration was 17.3 months (IQR 6.9-54.0); 17 children (41%) were still PN-dependent. One third of the children met criteria for at least 1 psychiatric classification (compared with 14% in age-matched general population). Anxiety disorders and attention deficit hyperactivity disorder were most common. In school-aged children (n = 29, 6-17 years), significantly increased emotional problems were consistently reported by children ( P = 0.011), parents ( P < 0.001), and teachers ( P = 0.004). In preschool children (n = 12, 1.5-5 years), no significant differences with normative data were found. Subclinical or clinical emotional problems were reported in 19 children (46%). Medical traumatic stress was present in 14%, and 22% of children had received psychological help for trauma before. Lower gastrointestinal related quality of life was associated with more emotional problems, but not PN-duration. CONCLUSIONS: Children with IF, particularly school-aged children, are at risk for psychological problems which is reflected by the high rate of received psychotherapy and the high rate of emotional problems and psychiatric classifications.

Challenges in body composition assessment using air-displacement plethysmography by BOD POD in pediatric and young adult patients.

BACKGROUND & AIMS: Air-Displacement-Plethysmography (ADP) by BOD POD is widely used for body fat assessment in children. Although validated in healthy subjects, studies about use in pediatric patients are lacking. We evaluated user experience and usability of ADP measurements with the BOD POD system in healthy children and pediatric and young adult patients. METHODS: Using the experiences of seven cohort studies, which included healthy children and patients aged 2-22 years, we retrospectively evaluated the user experience with the User Experience Questionnaire (UEQ) (n = 13) and interviews (n = 7). Technical performance was studied using the quality control data collected by the ADP-system. RESULTS: From 2016 to 2022, 1606 measurements were scheduled. BOD POD was mostly rated 'user-friendly', with a generally neutral evaluation on all scales of the UEQ. However, questionable reliability and validity of the results were frequently (86%) reported. We found a high technical failure-rate of the device, predominantly in stability (17%) and accuracy of the measurement (12%), especially in the 'pediatric option' for children aged <6 years. Measurement failure-rate was 38%, mostly due to subject's fear or device failure, especially in young and lean children, and in children with physical and/or intellectual disabilities. CONCLUSION: We conclude that ADP by BOD POD in children and young adults is non-invasive and user-friendly. However, in specific pediatric populations, BOD POD has several limitations and high (technical) failure-rates, especially in young children with aberrant body composition. We recommend caution when interpreting body composition results of pediatric patients as assessed with BOD POD using the current default settings.

Venous Thromboembolic Complications in Pediatric Gastrointestinal Diseases: Inflammatory Bowel Disease and Intestinal Failure.

In children with gastrointestinal disorders such as inflammatory bowel disease (IBD) and intestinal failure (IF), the risk of venous thromboembolism (VTE) is increased. VTE may lead to pulmonary embolism, sepsis and central line infection, stroke and post-thrombotic syndrome. The purpose of this review is to summarize current knowledge and recent advances around VTE management in pediatric gastroenterology with a focus on IBD and IF. The VTE incidence in children with IBD is reported to be around 4-30 per 10,000 patient-years, with higher incidences for hospitalized children. While in general, IF is less common than IBD, the VTE incidence in children with IF is around 750 per 10,000 patient-years. The most common risk factors for development of VTE involve deviations leading to Virchow's triad (endothelial damage, stasis, and hypercoagulability) and include active inflammation, particularly with colonic involvement, presence of a central venous catheter, underlying thrombophilia, reduced mobility, surgery, and hospitalization. Classes of anticoagulants used for treatment of VTE are low molecular weight heparins and vitamin K antagonists. However, the use of direct oral anticoagulants for treatment or prevention of VTE has not been studied in this pediatric population yet. Pediatric gastroenterologists apply different VTE prevention and treatment strategies due to lack of literature and lack of consensus. We discuss the role of primary and secondary prophylactic use of anticoagulants, and provide tools and recommendations for screening, prevention and management for the specific pediatric populations.

Ghrelin Levels in Children With Intestinal Failure Receiving Long-Term Parenteral Nutrition.

Background: Children with intestinal failure (IF) require parenteral nutrition (PN). Transition to oral and enteral nutrition (EN) can be difficult also due to abnormal gastrointestinal motility. The gut hormone ghrelin is increased in states of negative energy balance, functioning to preserve euglycemia, and also has appetite stimulating and prokinetic properties. We aimed to evaluate and compare ghrelin levels in children with IF, and to assess the relationship with PN-dependency. Methods: In this exploratory prospective multicenter study, plasma acylated (AG) and unacylated (UAG) ghrelin levels were measured in children with short bowel syndrome (SBS) and with functional IF (pseudo-obstruction or any enteropathy) and compared with healthy control subjects. Spearman's rho (rs) was used to assess correlations of AG and UAG with PN-dependency (%PN) and parenteral glucose intake. Results: Sixty-four samples from 36 IF-patients were analyzed. Median baseline AG and UAG levels were respectively 279.2 and 101.0 pg/mL in children with SBS (n = 16), 126.4 and 84.5 pg/mL in children with functional IF (n = 20) and 82.4 and 157.3 pg/mL in healthy children (n = 39). AG levels were higher in children with SBS and functional IF than in healthy children (p = 0.002 and p = 0.023, respectively). In SBS, AG positively correlated with %PN (rs = 0.5, p = 0.005) and parenteral glucose intake (rs = 0.6, p = 0.003). These correlations were not observed in functional IF. Conclusion: Children with IF had raised AG levels which could be related to starvation of the gut. The positive correlation between AG and glucose infusion rate in SBS suggests an altered glucoregulatory function.

Cognitive Outcomes in Children With Conditions Affecting the Small Intestine: A Systematic Review and Meta-analysis.

OBJECTIVES: The aim of the study was to assess cognitive outcomes in children with intestinal failure (IF) and children at high risk of IF with conditions affecting the small intestine requiring parenteral nutrition. METHODS: EMBASE, Cochrane, Web of Science, Google Scholar, MEDLINE, and PsycINFO were searched from inception to October 2020. Studies were included constituting original data on developmental quotient (DQ), intelligence quotient (IQ) and/or severe developmental delay/disability (SDD) rates assessed with standardized tests. We used appropriate standardized tools to extract data and assess study quality. We performed random effects meta-analyses to estimate pooled means of DQ/IQ and pooled SDD rates (general population mean for DQ/IQ: 100, for percentage with SDD: 1.8%) for 4 groups: IF, surgical necrotizing enterocolitis (NEC), abdominal wall defects (AWD), and midgut malformations (MM). Associations of patient characteristics with DQ/IQ were evaluated with meta-regressions. RESULTS: Thirty studies met the inclusion criteria. The pooled mean DQ/IQ for IF, NEC, AWD, and MM were 86.8, 83.3, 96.6, and 99.5, respectively. The pooled SDD rates for IF, NEC, AWD and MM were 28.6%, 32.8%, 8.5%, and 3.7%, respectively. Meta-regressions indicated that lower gestational age, longer hospital stay, and higher number of surgeries but not parenteral nutrition duration, were associated with lower DQ/IQ. CONCLUSIONS: Adverse developmental outcomes are common in children with IF and NEC, and to a much lesser extent in children with AWD and MM. It is important to monitor cognitive development in children with conditions affecting the small intestine and to explore avenues for prevention and remediation.

Necrotizing Enterocolitis in a Dutch Cohort of Very Preterm Infants: Prevalence, Mortality, and Long-Term Outcomes.

INTRODUCTION: To improve counseling of parents and to guide care strategies, we studied the disease course and outcomes of necrotizing enterocolitis (NEC) up to 2 years of corrected age (CA) from a multidisciplinary perspective. MATERIALS AND METHODS: This was a retrospective cohort study in preterm infants (birth weight < 1,500 g, gestational age < 32 weeks), diagnosed with NEC (Bell's stage ≥ II) from 2008 through 2020. Data on prevalence, mortality, surgery, intestinal failure (IF), growth, and neurodevelopment at 2-year follow-up were separately analyzed for medically and surgically treated children. RESULTS: Of 3,456 preterm infants, 200 (6%) were diagnosed with NEC, of whom 135 developed an indication for surgery within 7 days after the diagnosis; 28/135 died before surgery, and 37/107 died after an open-and-close procedure. An enterostomy was constructed in 62 patients and an end-to-end anastomosis in 15. The postoperative course was described for 77 patients, of whom 23 developed surgical complications (12/23 incisional hernias, 9/23 anastomotic strictures), 13/77 a short bowel, and 25/77 IF. Sixty-day survival after birth for medical NEC patients was 88% (hazard ratio [HR]: 0.698; p = 0.318), and for surgically treated NEC patients was 40% (HR: 3.729; p < 0.001). At 2-year follow-up, one patient received parenteral nutrition. Severe delay in weight for age, motor, and cognitive development was seen in 3, 6, and 2%, respectively. CONCLUSION: In this cohort, the mortality rate was high, especially in surgically treated NEC patients. The surgical complication rate is comparable to previous studies, but in surviving patients, persisting IF and severe delay in growth and neurodevelopment at 2 years CA were relatively rare.

Anthropometrics and fat mass, but not fat-free mass, are compromised in infants requiring parenteral nutrition after neonatal intestinal surgery.

BACKGROUND: Children with intestinal failure (IF) receiving long-term parenteral nutrition (PN) have altered body composition (BC), but data on BC changes from start of PN onwards are lacking. OBJECTIVES: We aimed to assess growth and BC in infants after neonatal intestinal surgery necessitating PN and at risk of IF, and to explore associations with clinical parameters. METHODS: A prospective cohort study in infants after intestinal surgery. IF was defined as PN dependency for >60 d. SD scores (SDS) for anthropometry were calculated until 6-mo corrected age. In a subgroup, fat mass (FM) and fat-free mass (FFM) were measured with air-displacement plethysmography at 2- and 6-mo corrected age. SDS for length-adjusted FM index and FFM index were calculated. Associations between cumulative amount of PN and BC parameters were analyzed with linear mixed-effect models. RESULTS: Ninety-five neonates were included (54% male, 35% born <32 wk) and 39 infants (41%) had IF. Studied infants had compromised anthropometric parameters during follow-up. At 6-mo corrected age, they remained smaller (median weight-for-age SDS -0.9 [IQR -1.5, 0.1], P < 0.001) than the normal population. In 57 infants, 93 BC measurements were performed. FM index SDS was lower than in healthy infants at 2- and 6-mo corrected age (-0.9 [-1.6, -0.3], P < 0.001 and -0.7 [-1.3, 0.1], P = 0.001, respectively), but FFM index SDS did not differ. A higher cumulative amount of PN predicted a higher FM index in female infants but lower FM index in male infants. CONCLUSIONS: In this cohort of infants receiving PN after intestinal surgery, compromised anthropometrics, decreased FM, and adequate FFM were observed during the first 6 mo. Male and female infants seemed to respond differently to PN when it comes to FM index. Continuing growth monitoring after the age of 6 mo is strongly recommended, and further research should explore the benefit of incorporating ongoing BC monitoring during follow-up.

Gut microbiota and its diet-related activity in children with intestinal failure receiving long-term parenteral nutrition.

BACKGROUND: This study characterized gut microbiota and its diet-related activity in children with intestinal failure (IF) receiving parenteral nutrition (PN) compared with those of healthy controls (HC) and in relation to disease characteristics. METHODS: The fecal microbiota and short-chain fatty acids (SCFAs) were measured in 15 IF patients (n = 68) and 25 HC (n = 25). RESULTS: Patients with IF had a lower bacterial load (P = .003), diversity (P < .001), evenness (P < .001) and richness (P = 0.006) than HC. Patients with surgical IF had lower diversity (P < .039) than those with functional IF. Propionic acid and butyric acid (p < .001) were lower and d-lactate and l-lactate were higher (p < 0.001) in IF patients than in HC. The energy supplied by PN (%PN) was negatively associated with microbiota diversity and SCFA profile. IF patients had more Escherichia-Shigella (P = .006), Cronobacter (P = .001), and Staphylococcus (Operational Taxonomic Unit 14, P < .001) and less Faecalibacterium (P < 0.001) and Ruminococcus 1 and 2 (P < .001). Duration of PN (P = .005), %PN (P = .005), and fiber intake (P = .011) were predictive of microbiota structure. Higher intake of enteral nutrition was associated with microbiota structure and function closer to those of HC. CONCLUSIONS: Microbiota composition and its diet-related function are altered in IF, with depletion of beneficial SCFAs and species and supraphysiological increase of potentially harmful pathobionts. The influence of this compositional and functional microbial dysbiosis on patients' outcomes and management warrants further exploration.

Longitudinal Development of Health-related Quality of Life and Fatigue in Children on Home Parenteral Nutrition.

OBJECTIVES: The aim of the study was to describe the longitudinal development of health-related quality of life (HRQOL) and fatigue in children with chronic intestinal failure (CIF) on home parenteral nutrition (PN) and compare these children to the general population. METHODS: Prospective, observational study conducted over 7 years in patients suffering from CIF receiving home PN from 2 tertiary hospitals in the Netherlands. Every 6 months, parents (if child <8 years old) or patients (if child ≥8 years old) completed 2 questionnaires: Pediatric Quality of Life Inventory 4.0 (PedsQL) Generic and Fatigue on the KLIK (kwaliteit van leven in kaart [Dutch Acronym for Quality of Life in Clinical Practice]) Patient Reported Outcome Measures portal, which were compared with the general population. Linear mixed models (LMMs) were constructed to investigate the course of HRQOL over time. RESULTS: Thirty-five patients were included (40% girls). At time of last KLIK contact, patients received HPN for a median of 5.3 years (interquartile range [IQR]: 2.9-9.7). In total, 272 questionnaires were completed. PedsQL generic total score for ages 5 to 7 and 8 to 12 years was significantly lower than the general population (P < 0.01 for both age groups) with effect sizes of 0.73 and 0.71, respectively. PedsQL fatigue total score for ages 5 to 7 years was also significantly lower (P = 0.01; effect size 0.70). LMMs for PedsQL Generic and Fatigue total score 2 to 7 and 8 to 18 years showed no significant coefficient for duration of home PN. CONCLUSIONS: Children suffering from CIF receiving home PN ages 5 to 12 years report lower HRQOL scores than the general population. HRQOL and fatigue do not change during long-term treatment with home PN in these children.

Exome sequencing in patient-parent trios suggests new candidate genes for early-onset primary sclerosing cholangitis.

BACKGROUND & AIMS: Primary sclerosing cholangitis (PSC) is a rare bile duct disease strongly associated with inflammatory bowel disease (IBD). Whole-exome sequencing (WES) has contributed to understanding the molecular basis of very early-onset IBD, but rare protein-altering genetic variants have not been identified for early-onset PSC. We performed WES in patients diagnosed with PSC ≤ 12 years to investigate the contribution of rare genetic variants to early-onset PSC. METHODS: In this multicentre study, WES was performed on 87 DNA samples from 29 patient-parent trios with early-onset PSC. We selected rare (minor allele frequency < 2%) coding and splice-site variants that matched recessive (homozygous and compound heterozygous variants) and dominant (de novo) inheritance in the index patients. Variant pathogenicity was predicted by an in-house developed algorithm (GAVIN), and PSC-relevant variants were selected using gene expression data and gene function. RESULTS: In 22 of 29 trios we identified at least 1 possibly pathogenic variant. We prioritized 36 genes, harbouring a total of 54 variants with predicted pathogenic effects. In 18 genes, we identified 36 compound heterozygous variants, whereas in the other 18 genes we identified 18 de novo variants. Twelve of 36 candidate risk genes are known to play a role in transmembrane transport, adaptive and innate immunity, and epithelial barrier function. CONCLUSIONS: The 36 candidate genes for early-onset PSC need further verification in other patient cohorts and evaluation of gene function before a causal role can be attributed to its variants.

Rectal Omeprazole in Infants With Gastroesophageal Reflux Disease: A Randomized Pilot Trial.

BACKGROUND AND OBJECTIVE: Omeprazole is a proton pump inhibitor that is used in acid suppression therapy in infants. Infants cannot swallow the oral tablets or capsules. Since, infants require a non-standard dose of omeprazole, the granules or tablets are often crushed or suspended in water or sodium bicarbonate, which may destroy the enteric coating. In this study we explore the efficacy and pharmacokinetics of rectally administered omeprazole in infants with gastroesophageal reflux disease (GERD) due to esophageal atresia (EA) or congenital diaphragmatic hernia (CDH) and compare these with orally administered omeprazole. METHODS: Infants (6-12 weeks postnatal and bodyweight > 3 kg) with EA or CDH and GERD were randomized to receive a single dose of 1 mg/kg omeprazole rectally or orally. The primary outcome was the percentage of infants for whom omeprazole was effective according to predefined criteria for 24-h intraesophageal pH. Secondary outcomes were the percentages of time that gastric pH was < 3 or < 4, as well as the pharmacokinetic parameters. RESULTS: Seventeen infants, 4 with EA and 13 with CDH, were included. The proportion of infants for whom omeprazole was effective was 56% (5 of 9 infants) after rectal administration and 50% (4 of 8 infants) after oral administration. The total reflux time in minutes and percentages and the number of reflux episodes of pH < 4 decreased statistically significantly after both rectal and oral omeprazole administration. Rectal and oral administration of omeprazole resulted in similar serum exposure. CONCLUSIONS: A single rectal omeprazole dose (1 mg/kg) results in consistent increases in intraesophageal and gastric pH in infants with EA- or CDH-related GERD, similar to an oral dose. Considering the challenges with existing oral formulations, rectal omeprazole presents as an innovative, promising alternative for infants with pathological GERD. CLINICAL TRIAL REGISTER: ClinicalTrials.gov Identifier: NCT00226044.

Standardized and Individualized Parenteral Nutrition Mixtures in a Pediatric Home Parenteral Nutrition Population.

OBJECTIVES: Studies evaluating efficacy or safety of standardized parenteral nutrition (PN) versus individualized PN are lacking. We aimed to assess effects on growth and safety of standardized PN compared with individualized PN in our Home PN group. METHODS: Descriptive cohort study in Dutch children on Home PN, in which standardized PN was compared with individualized PN. Both groups received similar micronutrient-supplementation. Primary outcome was growth over 2 years, secondary outcomes were electrolyte disturbances and biochemical abnormalities. Additionally, patients were matched for age to control for potential confounding characteristics. RESULTS: Fifty patients (50% girls, median age 6.5 years) were included, 16 (32%) received standardized PN mixtures. Age (11 vs 5 years), gestational age (39.2 vs 36.2 weeks) and PN duration (97 vs 39 months) were significantly higher in the group receiving standardized PN (P: ≤0.001; 0.027; 0.013 respectively). The standardized PN group showed an increase in weight-for-age (WFA), compared with a decrease in the individualized PN group (+0.38 SD vs -0.55 SD, P: 0.003). Electrolyte disturbances and biochemical abnormalities did not differ. After matching for age, resulting in comparable groups, no significant differences were demonstrated in WFA, height-for-age, or weight-for-height SD change. CONCLUSIONS: In children with chronic IF, over 2,5 years of age, standardized PN mixtures show a comparable effect on weight, height, and weight for height when compared with individualized PN mixtures. Also, standardized PN mixtures (with added micronutrients) seem noninferior to individualized PN mixtures in terms of electrolyte disturbances and basic biochemical abnormalities. Larger studies are needed to confirm these conclusions. TRIAL REGISTRATION: Academical Medical Center medical ethics committee number W18_079 #18.103.

Disease progression in paediatric- and adult-onset sclerosing cholangitis: Results from two independent Dutch registries.

BACKGROUND & AIMS: Sclerosing cholangitis (SC) is a severe liver disease leading to destruction of bile ducts. It is believed to run a milder course in children than in adults. To test this assumption, we evaluated time-to-complication curves in two independent paediatric-onset cohorts from the same geographical area. METHODS: Short-term disease outcomes were evaluated with an online clinical registry that was filled with data on children with SC diagnosed between 2000 and 2017 and who were followed bi-annually thereafter. Long-term disease outcomes were evaluated in a paediatric-onset subcohort derived from a previously published population-based study from the Netherlands. Time-to-complication in the first cohort was defined as the time from diagnosis until portal hypertension, biliary obstructions and infections, development of malignancy, or liver transplantation, whichever came first. In the second cohort time-to-complication was defined as the time until liver transplantation or PSC-related death. RESULTS: Median age at diagnosis in the first cohort (n = 86) was 12.3 years. In the first 5 years post-diagnosis 23% of patients developed complications. The patients in the population-based study (n = 683) were stratified into those diagnosed before the age of 18 years ('paediatric-onset' subcohort, n = 43) and those diagnosed after the age of 18 years ('adult-onset' subcohort, n = 640). Median age at diagnosis was 14.6 and 40.2 years, respectively. Median time-to-complication in the paediatric-onset and adult-onset subcohorts was not statistically different. CONCLUSION: Paediatric and adult-onset SC run a similar long-term disease course. Paediatricians who treat children with SC should monitor them closely to recognize early complications and control long-term sequelae.

Proteomics of human liver membrane transporters: a focus on fetuses and newborn infants.

BACKGROUND: Hepatic membrane transporters are involved in the transport of many endogenous and exogenous compounds, including drugs. We aimed to study the relation of age with absolute transporter protein expression in a cohort of 62 mainly fetus and newborn samples. METHODS: Protein expressions of BCRP, BSEP, GLUT1, MCT1, MDR1, MRP1, MRP2, MRP3, NTCP, OCT1, OATP1B1, OATP1B3, OATP2B1 and ATP1A1 were quantified with LC-MS/MS in isolated crude membrane fractions of snap-frozen post-mortem fetal and pediatric, and surgical adult liver samples. mRNA expression was quantified using RNA sequencing, and genetic variants with TaqMan assays. We explored relationships between protein expression and age (gestational age [GA], postnatal age [PNA], and postmenstrual age); between protein and mRNA expression; and between protein expression and genotype. RESULTS: We analyzed 36 fetal (median GA 23.4 weeks [range 15.3-41.3]), 12 premature newborn (GA 30.2 weeks [24.9-36.7], PNA 1.0 weeks [0.14-11.4]), 10 term newborn (GA 40.0 weeks [39.7-41.3], PNA 3.9 weeks [0.3-18.1]), 4 pediatric (PNA 4.1 years [1.1-7.4]) and 8 adult liver samples. A relationship with age was found for BCRP, BSEP, GLUT1, MDR1, MRP1, MRP2, MRP3, NTCP, OATP1B1 and OCT1, with the strongest relationship for postmenstrual age. For most transporters mRNA and protein expression were not correlated. No genotype-protein expression relationship was detected. DISCUSSION AND CONCLUSION: Various developmental patterns of protein expression of hepatic transporters emerged in fetuses and newborns up to four months of age. Postmenstrual age was the most robust factor predicting transporter expression in this cohort. Our data fill an important gap in current pediatric transporter ontogeny knowledge.

Proteomic Analysis of the Developmental Trajectory of Human Hepatic Membrane Transporter Proteins in the First Three Months of Life.

Human hepatic membrane-embedded transporter proteins are involved in trafficking endogenous and exogenous substrates. Even though impact of transporters on pharmacokinetics is recognized, little is known on maturation of transporter protein expression levels, especially during early life. We aimed to study the protein expression of 10 transporters in liver tissue from fetuses, infants, and adults. Transporter protein expression levels [ATP-binding cassette transporter (ABC)B1, ABCG2, ABCC2, ABCC3, bile salt efflux pump, glucose transporter 1, monocarboxylate transporter 1, organic anion transporter polypeptide (OATP)1B1, OATP2B1, and organic cation/carnitine transporter 2) were quantified using ultraperformance liquid chromatography tandem mass spectrometry in snap-frozen postmortem fetal, infant, and adult liver samples. Protein expression was quantified in isolated crude membrane fractions. The possible association between postnatal and postmenstrual age versus protein expression was studied. We studied 25 liver samples, as follows: 10 fetal [median gestational age 23.2 wk (range 16.4-37.9)], 12 infantile [gestational age at birth 35.1 wk (27.1-41.0), postnatal age 1 wk (0-11.4)], and 3 adult. The relationship of protein expression with age was explored by comparing age groups. Correlating age within the fetal/infant age group suggested four specific protein expression patterns, as follows: stable, low to high, high to low, and low-high-low. The impact of growth and development on human membrane transporter protein expression is transporter-dependent. The suggested age-related differences in transporter protein expression may aid our understanding of normal growth and development, and also may impact the disposition of substrate drugs in neonates and young infants.

Ontogeny of human hepatic and intestinal transporter gene expression during childhood: age matters.

Many drugs prescribed to children are drug transporter substrates. Drug transporters are membrane-bound proteins that mediate the cellular uptake or efflux of drugs and are important to drug absorption and elimination. Very limited data are available on the effect of age on transporter expression. Our study assessed age-related gene expression of hepatic and intestinal drug transporters. Multidrug resistance protein 2 (MRP2), organic anion transporting polypeptide 1B1 (OATP1B1), and OATP1B3 expression was determined in postmortem liver samples (fetal n = 6, neonatal n = 19, infant n = 7, child n = 2, adult n = 11) and multidrug resistance 1 (MDR1) expression in 61 pediatric liver samples. Intestinal expression of MDR1, MRP2, and OATP2B1 was determined in surgical small bowel samples (neonates n = 15, infants n = 3, adults n = 14). Using real-time reverse-transcription polymerase chain reaction, we measured fetal and pediatric gene expression relative to 18S rRNA (liver) and villin (intestines), and we compared it with adults using the 2(-∆∆Ct) method. Hepatic expression of MRP2, OATP1B1, and OATP1B3 in all pediatric age groups was significantly lower than in adults. Hepatic MDR1 mRNA expression in fetuses, neonates, and infants was significantly lower than in adults. Neonatal intestinal expressions of MDR1 and MRP2 were comparable to those in adults. Intestinal OATP2B1 expression in neonates was significantly higher than in adults. We provide new data that show organ- and transporter-dependent differences in hepatic and intestinal drug transporter expression in an age-dependent fashion. This suggests that substrate drug absorption mediated by these transporters may be subject to age-related variation in a transporter dependent pattern.

In vitro gastrointestinal model (TIM) with predictive power, even for infants and children?

There is a need for information on the bioavailability in pediatric patients of drugs from manipulated dosage forms when applied in combination with food and/or co-medication under realistic daily practice circumstances. We describe the development, validation and application of a dynamic, computer-controlled in vitro system mimicking the conditions in the upper gastrointestinal tract of neonates, infants and toddlers: TIMpediatric. Paracetamol and diclofenac in age-related food matrices and with esomeprazole co-medication were tested. The experiments showed relevant results on the impact of drug manipulation and co-medication on the availability for absorption of active compounds. Without ethical constraints, alternative approaches for oral dosing and new pediatric formulations can be studied in TIMpediatric with a high predictive value.

Ontogeny of oral drug absorption processes in children.

INTRODUCTION: A large proportion of prescribed drugs to children are administered orally. Age-related change in factors affecting oral absorption can have consequences for drug dosing. AREAS COVERED: For each process affecting oral drug absorption, a systematic search has been performed using Medline to identify relevant articles (from inception till February 2012) in humans. This review presents the findings on age-related changes of the following processes affecting oral drug absorption: gastric pH, gastrointestinal motility, bile salts, pancreatic function, intestinal pH, intestinal drug-metabolizing enzymes and transporter proteins. EXPERT OPINION: Clinicians should bear in mind the ontogeny of oral drug absorption processes when prescribing oral drugs to children. The authors' review shows large information gaps on almost all drug absorption processes. It is important that more knowledge is acquired on intestinal transit time, intestinal pH and the ontogeny of intestinal drug-metabolizing enzymes and drug transporter proteins. Furthermore, the ultimate goal in this field should be to predict more precisely the oral disposition of drugs in children across the entire pediatric age range.