Characterization of the Spectrum of Ophthalmic Changes in Patients With Alagille Syndrome.

Purpose: The purpose of this study was to characterize the phenotypic spectrum of ophthalmic findings in patients with Alagille syndrome. Methods: We conducted a retrospective, observational, multicenter, study on 46 eyes of 23 subjects with Alagille syndrome. We reviewed systemic and ophthalmologic data extracted from medical records, color fundus photography, fundus autofluorescence, optical coherence tomography, visual fields, electrophysiological assessments, and molecular genetic findings. Results: Cardiovascular abnormalities were found in 83% of all cases (of those, 74% had cardiac murmur), whereas 61% had a positive history of hepatobiliary issues, and musculoskeletal anomalies were present in 61% of all patients. Dysmorphic facies were present in 16 patients, with a broad forehead being the most frequent feature. Ocular symptoms were found in 91%, with peripheral vision loss being the most frequent complaint. Median (range) Snellen visual acuity of all eyes was 20/25 (20/20 to hand motion [HM]). Anterior segment abnormalities were present in 74% of the patients; of those, posterior embryotoxon was the most frequent finding. Abnormalities of the optic disc were found in 52%, and peripheral retinal abnormalities were the most frequent ocular finding in this series, found in 96% of all patients. Fifteen JAG1 mutations were identified in 16 individuals; of those, 6 were novel. Conclusions: This study reports a cohort of patients with Alagille syndrome in which peripheral chorioretinal changes were more frequent than posterior embryotoxon, the most frequent ocular finding according to a number of previous studies. We propose that these peripheral chorioretinal changes are a new hallmark to help diagnose this syndrome.

CRIMSON: An open-source software framework for cardiovascular integrated modelling and simulation.

In this work, we describe the CRIMSON (CardiovasculaR Integrated Modelling and SimulatiON) software environment. CRIMSON provides a powerful, customizable and user-friendly system for performing three-dimensional and reduced-order computational haemodynamics studies via a pipeline which involves: 1) segmenting vascular structures from medical images; 2) constructing analytic arterial and venous geometric models; 3) performing finite element mesh generation; 4) designing, and 5) applying boundary conditions; 6) running incompressible Navier-Stokes simulations of blood flow with fluid-structure interaction capabilities; and 7) post-processing and visualizing the results, including velocity, pressure and wall shear stress fields. A key aim of CRIMSON is to create a software environment that makes powerful computational haemodynamics tools accessible to a wide audience, including clinicians and students, both within our research laboratories and throughout the community. The overall philosophy is to leverage best-in-class open source standards for medical image processing, parallel flow computation, geometric solid modelling, data assimilation, and mesh generation. It is actively used by researchers in Europe, North and South America, Asia, and Australia. It has been applied to numerous clinical problems; we illustrate applications of CRIMSON to real-world problems using examples ranging from pre-operative surgical planning to medical device design optimization.

DUCT reveals architectural mechanisms contributing to bile duct recovery in a mouse model for Alagille syndrome.

Organ function depends on tissues adopting the correct architecture. However, insights into organ architecture are currently hampered by an absence of standardized quantitative 3D analysis. We aimed to develop a robust technology to visualize, digitalize, and segment the architecture of two tubular systems in 3D: double resin casting micro computed tomography (DUCT). As proof of principle, we applied DUCT to a mouse model for Alagille syndrome (Jag1Ndr/Ndr mice), characterized by intrahepatic bile duct paucity, that can spontaneously generate a biliary system in adulthood. DUCT identified increased central biliary branching and peripheral bile duct tortuosity as two compensatory processes occurring in distinct regions of Jag1Ndr/Ndr liver, leading to full reconstitution of wild-type biliary volume and phenotypic recovery. DUCT is thus a powerful new technology for 3D analysis, which can reveal novel phenotypes and provide a standardized method of defining liver architecture in mouse models.

Many essential parts of the body contain tubes: the liver for example, contains bile ducts and blood vessels. These tubes develop right next to each other, like entwined trees. To do their jobs, these ducts must communicate and collaborate, but they do not always grow properly. For example, babies with Alagille syndrome are born with few or no bile ducts, resulting in serious liver disease. Understanding the architecture of the tubes in their livers could explain why some children with this syndrome improve with time, but many others need a liver transplant. Visualising biological tubes in three dimensions is challenging. One major roadblock is the difficulty in seeing several tubular structures at once. Traditional microscopic imaging of anatomy is in two dimensions, using slices of tissue. This approach shows the cross-sections of tubes, but not how the ducts connect and interact. An alternative is to use micro computed tomography scans, which use X-rays to examine structures in three dimensions. The challenge with this approach is that soft tissues, which tubes in the body are made of, do not show up well on X-ray. One way to solve this is to fill the ducts with X-ray absorbing resins, making a cast of the entire tree structure. The question is, can two closely connected tree structures be distinguished if they are cast at the same time? To address this question, Hankeova, Salplachta et al. developed a technique called double resin casting micro computed tomography, or DUCT for short. The approach involved making casts of tube systems using two types of resin that show up differently under X-rays. The new technique was tested on a mouse model of Alagille syndrome. One resin was injected into the bile ducts, and another into the blood vessels. This allowed Hankeova, Salplachta et al. to reconstruction both trees digitally, revealing their length, volume, branching, and interactions. In healthy mice, the bile ducts were straight with uniform branches, but in mice with Alagille syndrome ducts were wiggly, and had extra branches in the centre of the liver. This new imaging technique could improve the understanding of tube systems in animal models of diseases, both in the liver and in other organs with tubes, such as the lungs or the kidneys. Hankeova, Salplachta et al. also lay a foundation for a deeper understanding of bile duct recovery in Alagille syndrome. In the future, DUCT could help researchers to see how mouse bile ducts change in response to experimental therapies.

Oral manifestations of Alagille syndrome.

Alagille syndrome (AGS) is a multisystem disorder classically involving liver and heart failure, characteristic vertebral and facial features and ocular abnormalities. AGS is caused by heterozygous mutations in JAG1 or NOTCH2, with variable phenotype penetrance. We report two cases of AGS in children with tooth defects characterised by green discolouration and hypomineralisation. The role of hyperbilirubinaemia (HB) in this atypical colour, a classical feature of AGS, has been well described. However, it does not totally explain the dental phenotype. As JAG1 and NOTCH2 mutations can affect bone development and considering common physiological pathways between bone and tooth mineralisation, both mutations could participate in this unusual dental phenotype. The role of HB and genetics in the development of the dental phenotype of AGS is discussed in two prototypical cases. Future research should focus on the underlying genetic component of tooth abnormalities.

Pathobiology of inherited biliary diseases: a roadmap to understand acquired liver diseases.

Bile duct epithelial cells, also known as cholangiocytes, regulate the composition of bile and its flow. Acquired, congenital and genetic dysfunctions in these cells give rise to a set of diverse and complex diseases, often of unknown aetiology, called cholangiopathies. New knowledge has been steadily acquired about genetic and congenital cholangiopathies, and this has led to a better understanding of the mechanisms of acquired cholangiopathies. This Review focuses on findings from studies on Alagille syndrome, polycystic liver diseases, fibropolycystic liver diseases (Caroli disease and congenital hepatic fibrosis) and cystic fibrosis-related liver disease. In particular, knowledge on the role of Notch signalling in biliary repair and tubulogenesis has been advanced by work on Alagille syndrome, and investigations in polycystic liver diseases have highlighted the role of primary cilia in biliary pathophysiology and the concept of biliary angiogenic signalling and its role in cyst growth and biliary repair. In fibropolycystic liver disease, research has shown that loss of fibrocystin generates a signalling cascade that increases ß-catenin signalling, activates the NOD-, LRR- and pyrin domain-containing 3 inflammasome, and promotes production of IL-1ß and other chemokines that attract macrophages and orchestrate the process of pericystic and portal fibrosis, which are the main mechanisms of progression in cholangiopathies. In cystic fibrosis-related liver disease, lack of cystic fibrosis transmembrane conductance regulator increases the sensitivity of epithelial Toll-like receptor 4 that sustains the secretion of nuclear factor-κB-dependent cytokines and peribiliary inflammation in response to gut-derived products, providing a model for primary sclerosing cholangitis. These signalling mechanisms may be targeted therapeutically and they offer a possibility for the development of novel treatments for acquired cholangiopathies.

Patient-specific modeling of right coronary circulation vulnerability post-liver transplant in Alagille's syndrome.

OBJECTIVES: Cardiac output (CO) response to dobutamine can identify Alagille's syndrome (ALGS) patients at higher risk of cardiovascular complications during liver transplantation. We propose a novel patient-specific computational methodology to estimate the coronary autoregulatory responses during different hemodynamic conditions, including those experienced in a post-reperfusion syndrome (PRS), to aid cardiac risk-assessment. MATERIAL AND METHODS: Data (pressure, flow, strain and ventricular volumes) from a 6-year-old ALGS patient undergoing catheter/dobutamine stress MRI (DSMRI) were used to parameterize a closed-loop coupled-multidomain (3D-0D) approach consisting of image-derived vascular models of pulmonary and systemic circulations and a series of 0D-lumped parameter networks (LPN) of the heart chambers and the distal arterial and venous circulations. A coronary microcirculation control model (CMCM) was designed to adjust the coronary resistance to match coronary blood flow (and thus oxygen delivery) with MVO2 requirements during Rest, Stress and a virtual PRS condition. RESULTS: In all three simulated conditions, diastolic dominated right coronary artery (RCA) flow was observed, due to high right ventricle (RV) afterload. Despite a measured 45% increase in CO, impaired coronary flow reserve (CFR) (~1.4) at Stress was estimated by the CMCM. During modeled PRS, a marked vasodilatory response was insufficient to match RV myocardial oxygen requirements. Such exhaustion of the RCA autoregulatory response was not anticipated by the DSMRI study. CONCLUSION: Impaired CFR undetected by DSMRI resulted in predicted myocardial ischemia in a computational model of PRS. This computational framework may identify ALGS patients at higher risk of complications during liver transplantation due to impaired coronary microvascular responses.

Clinical Features and Genetic Analysis of Pediatric Patients with Alagille Syndrome Presenting Initially with Liver Function Abnormalities.

Alagille syndrome (AGS) is a multisystem disorder and caused by mutations in JAG1 or NOTCH2 gene. The diagnosis of AGS is hampered by its highly variable clinical manifestations. We performed a retrospective analysis on 16 children diagnosed as having AGS in recent five years in our hospital. Cholestasis was seen in 15 patients (93.8%), heart disease in 12 (75%), characteristic facies in 7 (43.8%), and butterfly vertebrae in 7 (43.8%). Ophthalmology examination was not performed on all the patients. Further, serum biochemical parameters were compared between AGS and 16 biliary atresia (BA) patients who were confirmed by surgery. Elevated liver enzymes were seen in all the patients. Serum total cholesterol (TC) (P=0.0007), alanine aminotransferase (ALT) (P=0.0056), aspartate aminotransferase (AST) (P=0.0114), gamma-glutamyl transferase (GGT) (P=0.035) and total bile acid (TBA) levels (P=0.042) were significantly elevated in AGS patients compared to those in BA cases. However, there were no significant differences in serum total bilirubin (TB), conjugated bilirubin (CB) and albumin (ALB) between the two groups. We identified 14 different JAG1 gene variations and 1 NOTCH2 gene mutation in 16 Chinese AGS patients. Our study suggested clinical features of AGS are highly variable and not all patients meet the classical diagnostic criteria. It was suggested that hypercholesterolaemia and significantly elevated GGT, TBA and ALT may be helpful to diagnose AGS. Genetic testing is integral in the diagnosis of AGS.

JAG1 loss­of­function mutations contributed to Alagille syndrome in two Chinese families.

Alagille syndrome (ALGS) is primarily caused by jagged1 (JAG1) mutations, 70% of which are protein­truncating mutations. However, no mutation hotspots have been discovered, and the pathogenic mechanism is not fully understood. The aim of the present study was to analyze two protein­truncating JAG1 mutations detected in three Chinese ALGS patients. Mutation c.1261delT (p.Cys421Valfs) was identified in one patient with hepatic damage, xanthomas, facial abnormalities and cardiovascular defects, which was inherited from his father. The other mutation, c.1382_1383delAC (p.Asp461Glyfs), carried by a pair of monozygotic twins with hepatic damage, facial abnormalities and cardiovascular defects, was de novo. Biological experiments were performed to study the characteristics and function of these mutations. The p.Cys421Valfs and p.Asp461Glyfs mutant proteins appeared to be truncated in western blotting using anti­Flag bound to the N­terminus of JAG1. The RBP­Jκ­responsive reporter gene assay was used to investigate the ability of mutant JAG1 proteins to activate the Notch signaling pathway. The mutant proteins had a lower luciferase activity than the wild­type, indicating impaired transcriptional activation ability. Western blotting using soluble JAG1 from the culture medium revealed that the expression levels of the mutant proteins were lower than that of the wild­type, suggesting that less mutant JAG1 protein underwent proteolytic cleavage than the wild­type. In conclusion, these two loss­of­function JAG1 mutations may be associated with ALGS manifestations in these patients.

Wilms Tumor After Orthotopic Liver Transplant in a Patient With Alagille Syndrome.

We present a case of Wilms Tumor in a patient with Alagille syndrome 10 months after liver transplant. We explore a suggested genetic connection between these 2 diseases. In children with Wilms Tumor, we propose a pathoembryologic explanation for not just the tumor, but also for the cause of associated benign ureteral and renal parenchymal aberrancies that are commonly seen in the Alagille population. We also discuss the diagnostic and therapeutic challenges that can arise in a liver transplant patient with Alagille syndrome who subsequently develops a renal mass.

Systematic Review: The Epidemiology, Natural History, and Burden of Alagille Syndrome.

BACKGROUND AND AIM: Alagille syndrome (ALGS) is an inherited multisystem disorder typically manifesting as cholestasis, and potentially leading to end-stage liver disease and death. The aim of the study was to perform the first systematic review of the epidemiology, natural history, and burden of ALGS with a focus on the liver component. METHODS: Electronic databases and proceedings from key congresses were searched in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2009 guidelines. This analysis included publications reporting epidemiology, natural history, economic burden or health-related quality of life (HRQoL) outcomes in patients with ALGS. RESULTS: Of 525 screened publications, 20 met the inclusion criteria. Liver-related features included cholestasis (87%-100% of patients), jaundice (66%-85%), and cirrhosis (44%-95%). Between 15% and 47% of patients underwent liver transplantation and 4% to 14% received partial biliary diversion. Pruritus affected the majority of patients (59%-88%, of whom up to 45% had severe pruritus) and manifested during the first 10 years of life. Children with ALGS had significantly impaired HRQoL compared with healthy controls and those with other diseases. Itching was the symptom that most affected children with ALGS. No study assessed the economic burden of ALGS. CONCLUSIONS: Our findings consolidate information on the clinical course of ALGS, and highlight gaps in knowledge, most notably the absence of any research on the economic consequences of the disease. Further research is needed to establish the incidence of genetically confirmed ALGS. Disease-specific tools are also needed to improve the measurement of symptoms, such as itching, and better understand the impact of ALGS on HRQoL.

Computational simulation of postoperative pulmonary flow distribution in Alagille patients with peripheral pulmonary artery stenosis.

BACKGROUND: Up to 90% of individuals with Alagille syndrome have congenital heart diseases. Peripheral pulmonary artery stenosis (PPS), resulting in right ventricular hypertension and pulmonary flow disparity, is one of the most common abnormalities, yet the hemodynamic effects are ill-defined, and optimal patient management and treatment strategies are not well established. The purpose of this pilot study is to use recently refined computational simulation in the setting of multiple surgical strategies, to examine the influence of pulmonary artery reconstruction on hemodynamics in this population. MATERIALS AND METHODS: Based on computed tomography angiography and cardiac catheterization data, preoperative pulmonary artery models were constructed for 4 patients with Alagille syndrome with PPS (all male, age range: 0.6-2.9 years), and flow simulations with deformable walls were performed. Surgeon directed virtual surgery, mimicking the surgical procedure, was then performed to derive postoperative models. Postoperative simulation-derived hemodynamics and blood flow distribution were then compared with the clinical results. RESULTS: Simulations confirmed substantial resistance, resulting from preoperative severe ostial stenoses, and the use of newly developed adaptive outflow boundary conditions led to excellent agreement with in vivo measurements. Relief of PPS decreased pulmonary artery pressures and improved pulmonary flow distribution both in vivo and in silico with good correlation. CONCLUSIONS: Using adaptive outflow boundary conditions, computational simulations can estimate postoperative overall pulmonary flow distribution in patients with Alagille syndrome after pulmonary artery reconstruction. Obstruction relief along with pulmonary artery vasodilation determines postoperative pulmonary flow distribution and newer methods can incorporate these physiologic changes. Evolving blood flow simulations may be useful in surgical or transcatheter planning and in understanding the complex interplay among various obstructions in patients with peripheral pulmonary stenosis.

Alagille Syndrome: An Overview.

Alagille syndrome (AGS) is a highly complex, multisystem, autosomal dominant disorder that is caused by a defect in the Notch signaling pathway. This syndrome mainly affects the liver, causing significant cholestasis, which is caused by a paucity of intrahepatic bile ducts. There can be cardiac involvement, including, but not limited to, pulmonary stenosis and tetralogy of Fallot. Patients can also present with butterfly vertebra, ocular issues, and vascular events. Because this syndrome follows an autosomal dominant inheritance, it can have variable expression even in the same family line. For infants in the NICU who have a cardiac defect and persistent hyperbilirubinemia after two weeks of age, genetic testing for AGS should be considered. Early detection and diagnosis can lead to improved outcomes. In this discussion of AGS, the clinical features as well as management are discussed.

Requirement for Jagged1-Notch2 signaling in patterning the bones of the mouse and human middle ear.

Whereas Jagged1-Notch2 signaling is known to pattern the sensorineural components of the inner ear, its role in middle ear development has been less clear. We previously reported a role for Jagged-Notch signaling in shaping skeletal elements derived from the first two pharyngeal arches of zebrafish. Here we show a conserved requirement for Jagged1-Notch2 signaling in patterning the stapes and incus middle ear bones derived from the equivalent pharyngeal arches of mammals. Mice lacking Jagged1 or Notch2 in neural crest-derived cells (NCCs) of the pharyngeal arches display a malformed stapes. Heterozygous Jagged1 knockout mice, a model for Alagille Syndrome (AGS), also display stapes and incus defects. We find that Jagged1-Notch2 signaling functions early to pattern the stapes cartilage template, with stapes malformations correlating with hearing loss across all frequencies. We observe similar stapes defects and hearing loss in one patient with heterozygous JAGGED1 loss, and a diversity of conductive and sensorineural hearing loss in nearly half of AGS patients, many of which carry JAGGED1 mutations. Our findings reveal deep conservation of Jagged1-Notch2 signaling in patterning the pharyngeal arches from fish to mouse to man, despite the very different functions of their skeletal derivatives in jaw support and sound transduction.

Influence of complex childhood diseases on variation in growth and skeletal development.

The study of human growth and skeletal development by human biologists is framed by the larger theoretical concerns regarding the underpinnings of population variation and human evolution. This unique perspective is directly relevant to the assessment of child health and well-being at the individual and group level, as well as the construction of growth charts. Environmental, behavioral (nutrition and physical activity), and disease-related factors can prevent attainment of full genetic potential for growth. Undernutrition is most often the cause of growth faltering and poor skeletal development. Disease related factors, such as malabsorption, inflammation, and immobility also have profound effects. These effects will be illustrated with examples from diseases such as cystic fibrosis, inflammatory bowel disease, and Down syndrome. The need for separate growth charts for children with genetic disorders is often controversial because of potential medical and/or nutritional complications associated with some disorders. Children with Alagille syndrome and Down syndrome will be used to illustrate the advantages and limitations of syndrome-specific charts. This overview of health and disease effects on growth and skeletal development provides insights into the plasticity of human growth and its sensitivity to overall health and well-being.

Aterosclerosis calcificada del tronco de la arteria pulmonar, estenosis de las arterias pulmonares principales y dilatación postestenótica de arterias pulmonares segmentarias en un paciente con síndrome de Alagille / Calcified atherosclerosis of the pulmonary trunk, stenosis of the main pulmonary arteries, and post-stenotic dilation of segmental pulmonary arteries in a patient with Alagille syndrome

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Exocrine pancreatic function in children with Alagille syndrome.

Alagille syndrome (AGS) is often associated with symptoms of maldigestion, such as steatorrhea, hypotrophy and growth retardation. Exocrine pancreatic insufficiency was proposed as the underlying cause. We aimed to assess the exocrine pancreatic function with the use of different methods in AGS patients. Concentrations of fecal elastase-1 (FE1) and fecal lipase (FL) activities were measured in 33 children with AGS. The C-mixed triglyceride breath test (MTBT) in a subgroup comprising 15 patients. In all patients studied, FE1 concentrations and FL activities were normal. Abnormal MTBT results were documented in 4 (26.7%) patients. The FE1 and FL levels in MTBT-positive and MTBT-negative children did not differ. The results of this research do not confirm the presence of exocrine pancreatic dysfunction in AGS patients. Routine screening for exocrine pancreatic insufficiency of this group of patients is not necessary.

Surgical Techniques for Repair of Peripheral Pulmonary Artery Stenosis.

Peripheral pulmonary artery stenosis (PPAS) is a rare form of congenital heart disease that is most frequently associated with Williams and Alagille syndromes. These patients typically have systemic level right ventricular pressures secondary to obstruction at the lobar, segmental, and subsegmental branches. The current management of patients with PPAS remains somewhat controversial. We have pioneered an entirely surgical approach for the reconstruction of PPAS. This approach initially entailed a surgical patch augmentation of all major lobar branches and effectively reduced the right ventricular pressures by more than half. This was the first report demonstrating an effective approach to this disease. Over the past 5 years, we have gradually evolved our technique of reconstruction to include segmental and subsegmental branch stenoses. An important technical aspect of this approach entails the division of the main pulmonary and separation of the branch pulmonary arteries to access the lower lobe branches. Pulmonary artery homograft patches are used to augment hypoplastic pulmonary artery branches. In addition, we perform a Heinecke-Miculicz-type ostioplasty for isolated ostial stenoses. The technical details of the surgical approach to PPAS are outlined in this article and can also be used for other complex peripheral pulmonary artery reconstructions.

Early life predictive markers of liver disease outcome in an International, Multicentre Cohort of children with Alagille syndrome.

BACKGROUND & AIMS: Liver disease in Alagille syndrome is highly variable. Many of the patients presenting with severe cholestasis early in life improve spontaneously; 10-20%, however, have progressive disease. It is currently not possible to predict long-term hepatic outcomes in Alagille syndrome. This international, multicentre study was aimed at identifying early life predictors of liver disease outcome. METHODS: Retrospective clinical, laboratory and radiographic data from a cohort of 144 Alagille syndrome patients, whose long-term hepatic outcomes had been determined a priori based on previously published criteria, were collected. RESULTS: Sixty-seven patients had mild and 77 had severe hepatic outcome. Univariate analysis demonstrated that cholestasis and fibrosis on biopsy, as well as the presence of xanthomata were significantly different between the groups (P < 0.05 for all). Mixed model analysis revealed that total serum bilirubin and serum cholesterol were also associated with outcome (P = 0.001 and P = 0.002, respectively). Graphical representation of the data revealed a change in total bilirubin levels between 12 and 24 months of age in the mild group. Recursive partitioning identified a threshold for total bilirubin of 3.8 mg/dl (65 mmol/L) in that age-frame that differentiated between outcomes. A multivariable logistic regression model was developed using fibrosis, xanthomata and the total bilirubin cut-off of 3.8 mg/dl (65 mmol/L), which generated an area under the ROC curve of 0.792. CONCLUSIONS: The long-term hepatic outcomes of patients with Alagille syndrome can be predicted based on serum total bilirubin between the ages of 12-24 months combined with fibrosis on liver biopsy and the presence of xanthomata on physical examination.

Serum Autotaxin Activity Correlates With Pruritus in Pediatric Cholestatic Disorders.

OBJECTIVE: Pruritus is a common symptom of cholestatic liver disorders. The present study aimed at evaluating autotaxin (ATX), a lysophospholipase recently identified as potential cause for cholestatic pruritus, in pediatric cholestatic diseases presenting with or without itching. METHODS: A cohort of 45 children consisting of 14 patients experiencing itching (Alagille syndrome [n = 10], complete extrahepatic biliary atresia [n = 2], neonatal sclerosing cholangitis (n = 1), progressive familial intrahepatic cholestasis type 2 [n = 1]), 9 patients with bile acid synthesis defects (3ß-hydroxy-C27-steroid-oxidoreductase [n = 7] and Δ-3-oxosteroid-5ß-reductase deficiency [n = 2]), and 22 healthy children were studied. Serum ATX activity and total serum bile salt were determined enzymatically, ATX protein content was semiquantified by Western blotting. Using real-time polymerase chain reaction, ATX mRNA expression was studied in HepG2 cells treated with farnesoid-X-receptor agonists or vehicle. RESULTS: Serum ATX activity was increased in pruritic children with Alagille and other cholestatic syndromes (mean ±â€Šstandard deviation: 16.1 ±â€Š4.3 nmol ·â€ŠmL ·â€Šmin) compared with children with nonpruritic cholestatic diseases with bile acid synthesis defects (10.4 ±â€Š4.7 nmol ·â€ŠmL ·â€Šmin; P < 0.01) and healthy controls (7.6 ±â€Š2.3 nmol ·â€ŠmL ·â€Šmin; P < 0.001). ATX protein levels closely correlated with serum ATX activity. Serum ATX activity and total serum bile salt showed a linear correlation with itch intensity (r = 0.66, P < 0.001 and r = 0.80, P < 0.001, respectively). No correlation was observed between ATX activity and bilirubin. ATX mRNA expression in HepG2 cells was not induced by farnesoid-X-receptor ligands. CONCLUSIONS: Serum ATX activity correlated with itch intensity in children with cholestatic diseases. Bile salts did not increase ATX expression in vitro. ATX inhibitors may be useful antipruritic agents in pediatric cholestatic disorders.

Quality of Life and Its Determinants in a Multicenter Cohort of Children with Alagille Syndrome.

OBJECTIVES: To assess health-related quality of life (HRQOL) in children with Alagille syndrome (ALGS) in comparison with healthy and other liver disease cohorts, and to identify determinants of HRQOL in patients with ALGS. STUDY DESIGN: Within the Childhood Liver Disease Research Network prospective study of cholestasis, Pediatric Quality of Life Inventory (PedsQL) questionnaires were administered to 70 children with ALGS, 95 children with alpha-1-antitrypsin deficiency (A1ATD), and 49 children with other causes of chronic intrahepatic cholestasis (IHC) aged 5-18 years. Parent proxy PedsQL scores were recorded for children aged 2-18 years (98 ALGS, 123 A1ATD, and 68 IHC). RESULTS: Mean ages and total bilirubin (mg/dL) were ALGS 9.4 years; 4.4, A1ATD 9.5 years; 0.7, and IHC 10.3 years; 2.9. ALGS child PedsQL scores were lower than in healthy children and children with A1ATD (mean 73 vs 83; P = .001). Children with ALGS and IHC were similar, except in physical scores (73 vs 79; P = .05). Parents of children with ALGS perceived their children to have worse HRQOL than A1ATD (P ≤ .001) and marginally lower compared with IHC. Univariate analysis revealed ALGS child-reported scores were positively associated with better growth and inversely with total bilirubin. Growth failure, elevated international normalized ratio, and an intracardiac defect were predictive of poor parental scores (P ≤ .05). In multivariate analysis, only weight z-score remained significant for child- and parent-reported scores. CONCLUSIONS: HRQOL is impaired in children with ALGS compared with healthy and children with A1ATD, similar to children with IHC and is associated with growth failure, which is a potentially treatable cause of impaired HRQOL.