Event-free survival of maralixibat-treated patients with Alagille syndrome compared to a real-world cohort from GALA.

BACKGROUND AND AIMS: Alagille syndrome (ALGS) is characterized by chronic cholestasis with associated pruritus and extrahepatic anomalies. Maralixibat, an ileal bile acid transporter inhibitor, is an approved pharmacologic therapy for cholestatic pruritus in ALGS. Since long-term placebo-controlled studies are not feasible or ethical in children with rare diseases, a novel approach was taken comparing 6-year outcomes from maralixibat trials with an aligned and harmonized natural history cohort from the G lobal AL agille A lliance (GALA) study. APPROACH AND RESULTS: Maralixibat trials comprise 84 patients with ALGS with up to 6 years of treatment. GALA contains retrospective data from 1438 participants. GALA was filtered to align with key maralixibat eligibility criteria, yielding 469 participants. Serum bile acids could not be included in the GALA filtering criteria as these are not routinely performed in clinical practice. Index time was determined through maximum likelihood estimation in an effort to align the disease severity between the two cohorts with the initiation of maralixibat. Event-free survival, defined as the time to first event of manifestations of portal hypertension (variceal bleeding, ascites requiring therapy), surgical biliary diversion, liver transplant, or death, was analyzed by Cox proportional hazards methods. Sensitivity analyses and adjustments for covariates were applied. Age, total bilirubin, gamma-glutamyl transferase, and alanine aminotransferase were balanced between groups with no statistical differences. Event-free survival in the maralixibat cohort was significantly better than the GALA cohort (HR, 0.305; 95% CI, 0.189-0.491; p <0.0001). Multiple sensitivity and subgroup analyses (including serum bile acid availability) showed similar findings. CONCLUSIONS: This study demonstrates a novel application of a robust statistical method to evaluate outcomes in long-term intervention studies where placebo comparisons are not feasible, providing wide application for rare diseases. This comparison with real-world natural history data suggests that maralixibat improves event-free survival in patients with ALGS.

Disrupted BMP-9 Signaling Impairs Pulmonary Vascular Integrity in Hepatopulmonary Syndrome.

RATIONALE: Hepatopulmonary syndrome (HPS) is a severe complication of liver diseases characterized by abnormal dilatation of pulmonary vessels, resulting in impaired oxygenation. Recent research highlights the pivotal role of liver-produced bone morphogenetic protein (BMP)-9 in maintaining pulmonary vascular integrity. OBJECTIVES: This study aimed to investigate the involvement of BMP-9 in human and experimental HPS. METHODS: Circulating BMP-9 levels were measured in 63 healthy controls and 203 cirrhotic patients, with or without HPS. Two animal models of portal hypertension were employed: common bile duct ligation (CBDL) with cirrhosis and long-term partial portal vein ligation (PPVL) without cirrhosis. Additionally, the therapeutic effect of low-dose BMP activator FK506 was investigated, and the pulmonary vascular phenotype of BMP-9 knockout rats was analyzed. MEASUREMENTS AND MAIN RESULTS: Patients with HPS related to compensated cirrhosis demonstrated lower levels of circulating BMP-9 compared to patients without HPS. Severe cirrhosis patients exhibited consistently low levels of BMP-9. In animal models, HPS characteristics, including intrapulmonary vascular dilations (IPVDs) and alveolo-arterial gradient enlargement, were observed. HPS development in both rat models correlated with reduced intrahepatic BMP-9 expression, decreased circulating BMP-9 level and activity, and impaired pulmonary BMP-9 endothelial pathway. Daily treatment with FK506 for 2-weeks restored BMP pathway in the lungs, alleviating IPVDs, and improving gas exchange impairment. Furthermore, BMP-9 knockout rats displayed a pulmonary HPS phenotype, supporting its role in disease progression. CONCLUSION: The study findings suggest that portal hypertension-induced loss of BMP-9 signaling contributes to HPS development.

Predictors of 6-year event-free survival in Alagille syndrome patients treated with maralixibat, an ileal bile acid transporter inhibitor.

BACKGROUND AND AIMS: Refractory pruritus and other complications of cholestasis are indications for liver transplantation (LT) in patients with Alagille syndrome (ALGS). We evaluated predictors of event-free survival and transplant-free survival in patients with ALGS treated with maralixibat (MRX), an ileal bile acid transporter inhibitor. APPROACH AND RESULTS: We assessed patients with ALGS from 3 clinical trials of MRX with up to 6 years of follow-up. Event-free survival was defined as the absence of LT, surgical biliary diversion, hepatic decompensation, or death; transplant-free survival was the absence of LT or death. Forty-three potential predictors were evaluated, including age, pruritus (ItchRO[Obs] 0-4 scale), biochemistries, platelets, and serum bile acids. Harrell's concordance statistic assessed goodness-of-fit, and then, Cox proportional hazard models confirmed the statistical significance of the predictors identified. A further analysis was performed to identify cutoffs using a grid search. Seventy-six individuals met the criteria of receiving MRX for ≥48 weeks with laboratory values available at week 48 (W48). The median duration of MRX was 4.7 years (IQR: 1.6-5.8); 16 had events (10 LT, 3 decompensation, 2 death, and 1 surgical biliary diversion). The 6-year event-free survival improved with a clinically meaningful >1-point ItchRO(Obs) reduction from baseline to W48 (88% vs. 57%; p = 0.005), W48 bilirubin < 6.5 mg/dL (90% vs. 43%; p < 0.0001), and W48 serum bile acid < 200 µmol/L (85% vs. 49%; p = 0.001). These parameters were also predictive of 6-year transplant-free survival. CONCLUSIONS: Improvement in pruritus by 48 weeks, and lower W48 bilirubin and serum bile acid levels were associated with fewer events. These data may help identify potential markers of disease progression for ALGS patients treated with MRX.

Natural history of liver disease in a large international cohort of children with Alagille syndrome: Results from the GALA study.

BACKGROUND AND AIMS: Alagille syndrome (ALGS) is a multisystem disorder, characterized by cholestasis. Existing outcome data are largely derived from tertiary centers, and real-world data are lacking. This study aimed to elucidate the natural history of liver disease in a contemporary, international cohort of children with ALGS. APPROACH AND RESULTS: This was a multicenter retrospective study of children with a clinically and/or genetically confirmed ALGS diagnosis, born between January 1997 and August 2019. Native liver survival (NLS) and event-free survival rates were assessed. Cox models were constructed to identify early biochemical predictors of clinically evident portal hypertension (CEPH) and NLS. In total, 1433 children (57% male) from 67 centers in 29 countries were included. The 10 and 18-year NLS rates were 54.4% and 40.3%. By 10 and 18 years, 51.5% and 66.0% of children with ALGS experienced ≥1 adverse liver-related event (CEPH, transplant, or death). Children (>6 and ≤12 months) with median total bilirubin (TB) levels between ≥5.0 and <10.0 mg/dl had a 4.1-fold (95% confidence interval [CI], 1.6-10.8), and those ≥10.0 mg/dl had an 8.0-fold (95% CI, 3.4-18.4) increased risk of developing CEPH compared with those <5.0 mg/dl. Median TB levels between ≥5.0 and <10.0 mg/dl and >10.0 mg/dl were associated with a 4.8 (95% CI, 2.4-9.7) and 15.6 (95% CI, 8.7-28.2) increased risk of transplantation relative to <5.0 mg/dl. Median TB <5.0 mg/dl were associated with higher NLS rates relative to ≥5.0 mg/dl, with 79% reaching adulthood with native liver ( p < 0.001). CONCLUSIONS: In this large international cohort of ALGS, only 40.3% of children reach adulthood with their native liver. A TB <5.0 mg/dl between 6 and 12 months of age is associated with better hepatic outcomes. These thresholds provide clinicians with an objective tool to assist with clinical decision-making and in the evaluation of therapies.

Genotypic and phenotypic spectrum of infantile liver failure due to pathogenic TRMU variants.

PURPOSE: This study aimed to define the genotypic and phenotypic spectrum of reversible acute liver failure (ALF) of infancy resulting from biallelic pathogenic TRMU variants and determine the role of cysteine supplementation in its treatment. METHODS: Individuals with biallelic (likely) pathogenic variants in TRMU were studied within an international retrospective collection of de-identified patient data. RESULTS: In 62 individuals, including 30 previously unreported cases, we described 47 (likely) pathogenic TRMU variants, of which 17 were novel, and 1 intragenic deletion. Of these 62 individuals, 42 were alive at a median age of 6.8 (0.6-22) years after a median follow-up of 3.6 (0.1-22) years. The most frequent finding, occurring in all but 2 individuals, was liver involvement. ALF occurred only in the first year of life and was reported in 43 of 62 individuals; 11 of whom received liver transplantation. Loss-of-function TRMU variants were associated with poor survival. Supplementation with at least 1 cysteine source, typically N-acetylcysteine, improved survival significantly. Neurodevelopmental delay was observed in 11 individuals and persisted in 4 of the survivors, but we were unable to determine whether this was a primary or a secondary consequence of TRMU deficiency. CONCLUSION: In most patients, TRMU-associated ALF was a transient, reversible disease and cysteine supplementation improved survival.

Maralixibat Treatment Response in Alagille Syndrome is Associated with Improved Health-Related Quality of Life.

OBJECTIVE: The objective of this study was to assess the impact of treatment response to the ileal bile acid transporter inhibitor maralixibat on health-related quality of life (HRQoL) in children with Alagille syndrome. STUDY DESIGN: This analysis used data from the ICONIC trial, a phase 2 study with a 4-week double-blind, placebo-controlled, randomized drug withdrawal period in children with Alagille syndrome with moderate-to-severe pruritus. Clinically meaningful treatment response to maralixibat was defined a priori as a ≥1-point reduction in the Itch-Reported Outcome (Observer) score, from baseline to week 48. HRQoL was assessed using the Pediatric Quality of Life Inventory Generic Core, Family Impact, and Multidimensional Fatigue scale scores, which were collected via the caregiver. The minimal clinically important difference for HRQoL ranged from 4 to 5 points, depending on the scale. RESULTS: Twenty of the 27 patients (74%) included in this analysis achieved an Itch-Reported Outcome (Observer) treatment response at week 48. The mean (SD) change in Multidimensional Fatigue score was +25.8 (23.0) for responders vs -3.1 (19.8) for nonresponders (P = .03). Smaller and non-statistically significant mean changes were observed for the Pediatric Quality of Life Inventory Generic Core and Family Impact scores. Controlling for baseline Family Impact score, responders' Family Impact scores increased an average of 16.9 points over 48 weeks compared with non-responders (P = .05). Smaller and non-statistically significant point estimates were observed for the Pediatric Quality of Life Inventory Generic Core and Multidimensional Fatigue scores. CONCLUSION: The significant improvements in pruritus seen with maralixibat at week 48 of the ICONIC study are clinically meaningful and are associated with improved HRQoL. TRIAL REGISTRATION: ClinicalTrials.gov: NCT02160782.

A Retrospective Multicentric Study of 34 Patients with Niemann-Pick Type C Disease and Early Liver Involvement in France.

OBJECTIVE: To describe the clinical features and course of liver involvement in a cohort of patients with Niemann-Pick type C disease (NP-C), a severe lysosomal storage disorder. STUDY DESIGN: Patients with genetically confirmed NP-C (NPC1, n = 31; NPC2, n = 3) and liver involvement before age 6 months were retrospectively included. Clinical, laboratory test, and imaging data were collected until the last follow-up or death; available liver biopsy specimens were studied using anti-CD68 immunostaining. RESULTS: At initial evaluation (median age, 17 days of life), all patients had hepatomegaly, 33 had splenomegaly, and 30 had neonatal cholestasis. Portal hypertension and liver failure developed in 9 and 4 patients, respectively. Liver biopsy studies, performed in 16 patients, revealed significant fibrosis in all 16 and CD68+ storage cells in 15. Serum alpha-fetoprotein concentration measured in 21 patients was elevated in 17. Plasma oxysterol concentrations were increased in the 16 patients tested. Four patients died within 6 months of life, including 3 from liver involvement. In patients who survived beyond age 6 months (median follow-up, 6.1 years), cholestasis regressed in all, and portal hypertension regressed in all but 1; 25 patients developed neurologic involvement, which was fatal in 16 patients. CONCLUSIONS: Liver involvement in NP-C consisted of transient neonatal cholestasis with hepatosplenomegaly, was associated with liver fibrosis, and was responsible for death in 9% of patients. The combination of liver anti-CD68 immunostaining, serum alpha-fetoprotein measurement, and studies of plasma biomarkers should facilitate early identification of NP-C.

Pediatric hepatic hemangiomas: spectrum and prognostic significance of initial ultrasound findings.

BACKGROUND: Hepatic hemangiomas may be associated with serious complications; however, it is unknown whether ultrasound (US) features can predict complications. OBJECTIVE: To analyze initial US features of hepatic hemangiomas predictive of complications. MATERIALS AND METHODS: This is a single-center retrospective cohort study of clinical, biological, and imaging data of infants with hepatic hemangioma between 2000 and 2018. Patients were categorized as having or not having any complication(s). Associations between initial US features and complications were analyzed through logistic regression. Receiver operating characteristic (ROC) curve analyses were performed to determine optimal cutoff values for continuous variables. Stepwise forward logistic regression was used to construct risk prediction models with training and validation sets. Model calibration and discrimination were evaluated using Hosmer-Lemeshow tests, area under the ROC curve, and overall accuracy. RESULTS: Of 112 infants with hepatic hemangioma, 67 (60%) had focal, 32 (28%) had multifocal, and 13 (12%) had diffuse lesions, with complication rates of 51%, 34%, and 92%, respectively, mostly cardiac (54/57, 95%). The US characteristics of the hemangiomas were diverse. Risk factors for complications included diffuse subtype; large tumor volume (focal forms); elevated peak systolic hepatic arterial velocity (PSV); and hepatic vein dilation. For focal forms, initial tumor volume >40 ml and PSV >100 cm/s had >70% sensitivity and specificity, respectively, to predict complications; a model including these variables had 75% overall accuracy in the validation set. For multifocal/diffuse forms, a PSV >115 cm/s had sensitivity and specificity to predict complications of >70%; a model including this variable had 78% overall accuracy in the validation set. CONCLUSION: Diffuse subtype, large tumor volume, elevated hepatic arterial PSV, and hepatic vein dilation are risk factors for complications of hepatic hemangiomas.

Modern therapeutic approaches to liver-related disorders.

The liver is a key production and processing site that is essential for health. Liver dysfunction can result in both systemic and liver-specific diseases. To combat these diseases, genetic approaches have been developed that have high liver tropism and are based on gene addition/editing or gene silencing. The gene addition/editing approach has yielded encouraging clinical data on the use of viral vectors in patients with haemophilia, as well as neuromuscular diseases, and has led to trials for liver-related disorders. However, the immune response and the long-term stability of exogenous expression remain important challenges. Gene editing and mRNA therapy have yielded first in-human proof-of-concept therapeutics and vaccines, but the road to the treatment of liver-related disorders remains long. Gene silencing is accomplished primarily via antisense oligonucleotides and small-interfering RNAs (siRNAs). siRNA modification with N-acetyl galactosamine results in hepatocellular-specific targeting and catapulted the liver to the centre of siRNA research. Several siRNA drugs for liver-related disorders have recently been approved, and the pipeline of drugs under investigation is crowded. Loss-of-function mutations might also be treated with enzyme substitution therapy. This review summarises current genetic approaches as well as key enzyme substitution therapies, focusing on recently approved compounds, potential adverse effects, and future challenges. Collectively, these recent advances place the liver at the forefront of precision medicine for metabolic and genetic diseases and are expected to transform the care and treatment of patients with both liver-specific and systemic diseases.

Efficacy and safety of maralixibat treatment in patients with Alagille syndrome and cholestatic pruritus (ICONIC): a randomised phase 2 study.

BACKGROUND: Alagille syndrome is a rare genetic disease that often presents with severe cholestasis and pruritus. There are no approved drugs for management. Maralixibat, an apical, sodium-dependent, bile acid transport inhibitor, prevents enterohepatic bile acid recirculation. We evaluated the safety and efficacy of maralixibat for children with cholestasis in Alagille syndrome. METHODS: ICONIC was a placebo-controlled, randomised withdrawal period (RWD), phase 2b study with open-label extension in children (aged 1-18 years) with Alagille syndrome (NCT02160782). Eligible participants had more than three times the normal serum bile acid (sBA) levels and intractable pruritus. After 18 weeks of maralixibat 380 µg/kg once per day, participants were randomly assigned (1:1) to continue maralixibat or receive placebo for 4 weeks. Subsequently, all participants received open-label maralixibat until week 48. During the long-term extension (204 weeks reported), doses were increased up to 380 µg/kg twice per day. The primary endpoint was the mean sBA change during the RWD in participants with at least 50% sBA reduction by week 18. Cholestastic pruritus was assessed using observer-rated, patient-rated, and clinician-rated 0-4 scales. The safety population was defined as all participants who had received at least one dose of maralixibat. This trial was registered with ClinicalTrials.gov, NCT02160782, and is closed to recruitment. FINDINGS: Between Oct 28, 2014, and Aug 14, 2015, 31 participants (mean age 5·4 years [SD 4·25]) were enrolled and 28 analysed at week 48. Of the 29 participants who entered the randomised drug withdrawal period, ten (34%) were female and 19 (66%) were male. In the RWD, participants switched to placebo had significant increases in sBA (94 µmol/L, 95% CI 23 to 164) and pruritus (1·7 points, 95% CI 1·2 to 2·2), whereas participants who continued maralixibat maintained treatment effect. This study met the primary endpoint (least square mean difference -117 µmol/L, 95% CI -232 to -2). From baseline to week 48, sBA (-96 µmol/L, -162 to -31) and pruritus (-1·6 pts, -2·1 to -1·1) improved. In participants who continued to week 204 (n=15) all improvements were maintained. Maralixibat was generally safe and well tolerated throughout. The most frequent adverse events were gastrointestinal related. Most adverse events were self-limiting in nature and mild-to-moderate in severity. INTERPRETATION: In children with Alagille syndrome, maralixibat is, to our knowledge, the first agent to show durable and clinically meaningful improvements in cholestasis. Maralixibat might represent a new treatment paradigm for chronic cholestasis in Alagille syndrome. FUNDING: Mirum Pharmaceuticals.

Galaxy Is a Suitable Bioinformatics Platform for the Molecular Diagnosis of Human Genetic Disorders Using High-Throughput Sequencing Data Analysis: Five Years of Experience in a Clinical Laboratory.

BACKGROUND: To date, the usage of Galaxy, an open-source bioinformatics platform, has been reported primarily in research. We report 5 years' experience (2015 to 2020) with Galaxy in our hospital, as part of the "Assistance Publique-Hôpitaux de Paris" (AP-HP), to demonstrate its suitability for high-throughput sequencing (HTS) data analysis in a clinical laboratory setting. METHODS: Our Galaxy instance has been running since July 2015 and is used daily to study inherited diseases, cancer, and microbiology. For the molecular diagnosis of hereditary diseases, 6970 patients were analyzed with Galaxy (corresponding to a total of 7029 analyses). RESULTS: Using Galaxy, the time to process a batch of 23 samples-equivalent to a targeted DNA sequencing MiSeq run-from raw data to an annotated variant call file was generally less than 2 h for panels between 1 and 500 kb. Over 5 years, we only restarted the server twice for hardware maintenance and did not experience any significant troubles, demonstrating the robustness of our Galaxy installation in conjunction with HTCondor as a job scheduler and a PostgreSQL database. The quality of our targeted exome sequencing method was externally evaluated annually by the European Molecular Genetics Quality Network (EMQN). Sensitivity was mean (SD)% 99 (2)% for single nucleotide variants and 93 (9)% for small insertion-deletions. CONCLUSION: Our experience with Galaxy demonstrates it to be a suitable platform for HTS data analysis with vast potential to benefit patient care in a clinical laboratory setting.

Pharmacological Premature Termination Codon Readthrough of ABCB11 in Bile Salt Export Pump Deficiency: An In Vitro Study.

BACKGROUND AND AIMS: Progressive familial intrahepatic cholestasis type 2 (PFIC2) is a severe hepatocellular cholestasis due to biallelic mutations in ABCB11 encoding the canalicular bile salt export pump (BSEP). Nonsense mutations are responsible for the most severe phenotypes. The aim was to assess the ability of drugs to induce readthrough of six nonsense mutations (p.Y354X, p.R415X, p.R470X, p.R1057X, p.R1090X, and p.E1302X) identified in patients with PFIC2. APPROACH AND RESULTS: The ability of G418, gentamicin, and PTC124 to induce readthrough was studied using a dual gene reporter system in NIH3T3 cells. The ability of gentamicin to induce readthrough and to lead to the expression of a full-length protein was studied in human embryonic kidney 293 (HEK293), HepG2, and Can 10 cells using immunodetection assays. The function of the gentamicin-induced full-length protein was studied by measuring the [3 H]-taurocholate transcellular transport in stable Madin-Darby canine kidney clones co-expressing Na+-taurocholate co-transporting polypeptide (Ntcp). Combinations of gentamicin and chaperone drugs (ursodeoxycholic acid, 4-phenylbutyrate [4-PB]) were investigated. In NIH3T3, aminoglycosides significantly increased the readthrough level of all mutations studied, while PTC124 only slightly increased the readthrough of p.E1302X. Gentamicin induced a readthrough of p.R415X, p.R470X, p.R1057X, and p.R1090X in HEK293 cells. The resulting full-length proteins localized within the cytoplasm, except for BsepR1090X , which was also detected at the plasma membrane of human embryonic kidney HEK293 and at the canalicular membrane of Can 10 and HepG2 cells. Additional treatment with 4-PB and ursodeoxycholic acid significantly increased the canalicular proportion of full-length BsepR1090X protein in Can 10 cells. In Madin-Darby canine kidney clones, gentamicin induced a 40% increase of the BsepR1090X [3 H]-taurocholate transport, which was further increased with additional 4-PB treatment. CONCLUSION: This study constitutes a proof of concept for readthrough therapy in selected patients with PFIC2 with nonsense mutations.

Impact of Genotype, Serum Bile Acids, and Surgical Biliary Diversion on Native Liver Survival in FIC1 Deficiency.

BACKGROUND AND AIMS: Mutations in ATPase phospholipid transporting 8B1 (ATP8B1) can lead to familial intrahepatic cholestasis type 1 (FIC1) deficiency, or progressive familial intrahepatic cholestasis type 1. The rarity of FIC1 deficiency has largely prevented a detailed analysis of its natural history, effects of predicted protein truncating mutations (PPTMs), and possible associations of serum bile acid (sBA) concentrations and surgical biliary diversion (SBD) with long-term outcome. We aimed to provide insights by using the largest genetically defined cohort of patients with FIC1 deficiency to date. APPROACH AND RESULTS: This multicenter, combined retrospective and prospective study included 130 patients with compound heterozygous or homozygous predicted pathogenic ATP8B1 variants. Patients were categorized according to the number of PPTMs (i.e., splice site, frameshift due to deletion or insertion, nonsense, duplication), FIC1-A (n = 67; no PPTMs), FIC1-B (n = 29; one PPTM), or FIC1-C (n = 34; two PPTMs). Survival analysis showed an overall native liver survival (NLS) of 44% at age 18 years. NLS was comparable among FIC1-A, FIC1-B, and FIC1-C (% NLS at age 10 years: 67%, 41%, and 59%, respectively; P = 0.12), despite FIC1-C undergoing SBD less often (% SBD at age 10 years: 65%, 57%, and 45%, respectively; P = 0.03). sBAs at presentation were negatively associated with NLS (NLS at age 10 years, sBAs < 194 µmol/L: 49% vs. sBAs ≥ 194 µmol/L: 15%; P = 0.03). SBD decreased sBAs (230 [125-282] to 74 [11-177] µmol/L; P = 0.005). SBD (HR 0.55, 95% CI 0.28-1.03, P = 0.06) and post-SBD sBA concentrations < 65 µmol/L (P = 0.05) tended to be associated with improved NLS. CONCLUSIONS: Less than half of patients with FIC1 deficiency reach adulthood with native liver. The number of PPTMs did not associate with the natural history or prognosis of FIC1 deficiency. sBA concentrations at initial presentation and after SBD provide limited prognostic information on long-term NLS.

A Model for Early Endoscopic Detection of High-Risk Gastroesophageal Varices in Children With Biliary Atresia.

OBJECTIVE: In children with biliary atresia and portal hypertension, progression to gastroesophageal varices carrying a risk of bleeding depends on age, total serum bilirubin concentration and initial endoscopic features. We report an attempt to use these factors for early detection of high-risk varices (HRVs). METHODS: Based on different combinations of these factors, a model was set to estimate the probabilities of emergence of HRVs at various time intervals. A 10% probability was chosen to set the date of the next endoscopy in children who did not display HRVs initially. A total of 113 children without HRVs who underwent their first endoscopy before age 8 in 2013-2020 were included. A comparison was made with children seen during the period 1990-2012 when this model was not used. RESULTS: In all, 65 of the 113 children underwent one to five additional endoscopies at dates set according to the model. The emergence of HRVs was recorded in 22 children after a mean interval of 14 months and was managed by endoscopic primary prophylaxis in all but one who underwent liver transplantation. Three other children bled before the next planned endoscopy. Compared with 175 children of the same age ranges without HRVs in the period 1990-2012, the use of the model was associated with a faster detection of HRVs with a lower number of endoscopic procedures (P  = 0.0022 and P  = 0.023, respectively). CONCLUSION: The results suggest that the model reported may be a useful tool for the early detection of HRVs to allow primary prophylaxis of bleeding.

Efficacy and Safety of Endoscopic Primary Prophylaxis of Bleeding in Children With High-Risk Gastroesophageal Varices.

OBJECTIVES: Primary prophylaxis of bleeding is debated in children with gastroesophageal varices; one of the reasons is the limited number of studies concerning its efficacy and safety. We report our experience with endoscopic primary prophylaxis. METHODS: From 2006 to 2019, 145 children (median age, 3.5 years; cirrhosis, n = 116) with high-risk gastroesophageal varices underwent primary prophylaxis (banding, n = 114; sclerotherapy n = 31, primarily in smaller children). RESULTS: We observed the eradication of varices in 93% of children after a mean of 6 months, at least one recurrence of varices in 45% after eradication, and gastrointestinal bleeding in 17% of children. Irrespective of the cause of portal hypertension, grade 3 esophageal varices, presence of gastric varices along the cardia and a lower composite score of endoscopic severity were associated with a worse probability of eradication, a longer time to eradication and a lower risk of a first recurrence and of bleeding following the procedure, respectively. Ten-year probabilities of overall survival and of bleeding-free survival were 95% and 75%, respectively. CONCLUSIONS: Endoscopic primary prophylaxis of variceal bleeding is reasonably effective and safe in children with high-risk gastroesophageal varices. Worse results are observed in children with more advanced endoscopic features. This pleads for endoscopic screening in children with portal hypertension and early detection of varices warranting primary prophylaxis.

Acute Hepatitis of Unknown Etiology Among Young Children: Research Agenda by the ESPGHAN Hepatology Committee.

In April 2022, an increased incidence of acute hepatitis cases of unknown etiology among previously healthy children across the United Kingdom was described. Since, more than 270 cases from the United Kingdom and hundreds more from all across the world have been reported. The majority of affected children were younger than 6 years of age. The clinical presentation was nonspecific with diarrhea and vomiting usually preceding the appearance of jaundice, abdominal pain, nausea, and malaise. Approximately 5% have required liver transplantation. An infectious etiology has been considered likely given the epidemiological and clinical features of the reported cases. Between 50 and 60% of the children tested were diagnosed with adenovirus infection although a clear etiological connection has still to be demonstrated. No link with SARS-CoV-2 infection and COVID-19 vaccine was found. What is not clear to date is whether the high number of acute hepatitis cases reported is related to a true increase in incidence or heightened awareness following on from the initial reports from the United Kingdom. The Hepatology Committee of the European Society of Pediatric Gastroenterology, Hepatology and Nutrition (ESPGHAN) developed a paper on the current outbreak of acute hepatitis of unknown etiology recognizing its importance and the need of approaching the current situation with a scientifically rigorous approach. The aims of the article are to summarize the current knowledge and to identify the most pertinent issues regarding the diagnosis and management of this condition and the research questions raised.

Spontaneous evolution patterns of focal congenital hepatic hemangiomas: a case series of 25 patients.

BACKGROUND: Hepatic hemangiomas are the most common benign liver tumors of infancy. They are termed congenital if fully developed at birth or infantile if they appear in the first weeks of life. Previous studies suggested that most focal hepatic hemangiomas are congenital in nature, exhibit no postnatal growth and have an evolution that parallels their cutaneous counterparts. They are subdivided by pattern of involution, whether rapidly involuting (RICH), partially involuting (PICH) or non-involuting (NICH) congenital hemangiomas. In our experience, some focal hepatic hemangiomas show postnatal growth, behaving like infantile forms. OBJECTIVES: To analyze the spontaneous evolution of focal congenital hepatic hemangiomas with quantification of tumor volume changes over time and to identify initial postnatal ultrasound (US) imaging biomarkers predictive of their evolution pattern. MATERIALS AND METHODS: A retrospective review of clinical, imaging and pathology data of children diagnosed with focal congenital hepatic hemangioma (prenatal diagnosis or age at diagnosis <7 days and/or glucose transporter protein 1 [GLUT1]-negative tumor) diagnosed between 2000 and 2018 was performed with analysis of tumor volume changes over time. Exclusion criteria were treatment inducing a tumor volume change (hepatic artery embolization, propranolol, or corticosteroids), imaging follow-up less than 1 month or fewer than two US examinations. Volumetric analysis was based on US and cross-sectional imaging. Lesion volumes were estimated using the standard ellipsoid formula. A 35% margin of error was assumed for tumor volume variation to account for variability in measurements. Imaging studies, including US, computed tomography, and magnetic resonance imaging, were reviewed and initial postnatal US features were correlated with evolution pattern. RESULTS: Twenty-five patients with focal congenital hepatic hemangiomas were included. The median follow-up time was 46.5 months (range: 4-144 months). Eight (32%) lesions showed postnatal growth before involuting, without signs of intralesional hemorrhage, as do cutaneous infantile hemangiomas. The other 17 (68%) lesions exhibited a strict decrease in volume with age, of which 15 underwent complete involution (8 before age 18 months and 7 after age 18 months) and 2 underwent partial involution. The different evolution patterns of focal congenital hepatic hemangiomas showed overlapping imaging features and we found no initial US feature to be significantly associated with postnatal growth. However, large vascular spaces with marked vascularity at US were noted in three of the eight rapidly involuting lesions. CONCLUSION: Focal congenital hepatic hemangiomas are not the equivalent of cutaneous RICH, as some may increase in size and tumor regression may be rapid or slow. The different evolution patterns of focal congenital hepatic hemangiomas show overlapping US features.

In Vitro Rescue of the Bile Acid Transport Function of ABCB11 Variants by CFTR Potentiators.

ABCB11 is responsible for biliary bile acid secretion at the canalicular membrane of hepatocytes. Variations in the ABCB11 gene cause a spectrum of rare liver diseases. The most severe form is progressive familial intrahepatic cholestasis type 2 (PFIC2). Current medical treatments have limited efficacy. Here, we report the in vitro study of Abcb11 missense variants identified in PFIC2 patients and their functional rescue using cystic fibrosis transmembrane conductance regulator potentiators. Three ABCB11 disease-causing variations identified in PFIC2 patients (i.e., A257V, T463I and G562D) were reproduced in a plasmid encoding an Abcb11-green fluorescent protein. After transfection, the expression and localization of the variants were studied in HepG2 cells. Taurocholate transport activity and the effect of potentiators were studied in Madin-Darby canine kidney (MDCK) clones coexpressing Abcb11 and the sodium taurocholate cotransporting polypeptide (Ntcp/Slc10A1). As predicted using three-dimensional structure analysis, the three variants were expressed at the canalicular membrane but showed a defective function. Ivacaftor, GLP1837, SBC040 and SBC219 potentiators increased the bile acid transport of A257V and T463I and to a lesser extent, of G562D Abcb11 missense variants. In addition, a synergic effect was observed when ivacaftor was combined with SBC040 or SBC219. Such potentiators could represent new pharmacological approaches for improving the condition of patients with ABCB11 deficiency due to missense variations affecting the function of the transporter.

Loss-of-Function Mutations in UNC45A Cause a Syndrome Associating Cholestasis, Diarrhea, Impaired Hearing, and Bone Fragility.

Despite the rapid discovery of genes for rare genetic disorders, we continue to encounter individuals presenting with syndromic manifestations. Here, we have studied four affected people in three families presenting with cholestasis, congenital diarrhea, impaired hearing, and bone fragility. Whole-exome sequencing of all affected individuals and their parents identified biallelic mutations in Unc-45 Myosin Chaperone A (UNC45A) as a likely driver for this disorder. Subsequent in vitro and in vivo functional studies of the candidate gene indicated a loss-of-function paradigm, wherein mutations attenuated or abolished protein activity with concomitant defects in gut development and function.

Adenosine kinase deficiency: Three new cases and diagnostic value of hypermethioninemia.

Adenosine kinase (ADK) deficiency is characterized by liver disease, dysmorphic features, epilepsy and developmental delay. This defect disrupts the adenosine/AMP futile cycle and interferes with the upstream methionine cycle. We report the clinical, histological and biochemical courses of three ADK children carrying two new mutations and presenting with neonatal cholestasis and neurological disorders. One of them died of liver failure whereas the other two recovered from their liver damage. As the phenotype was consistent with a mitochondrial disorder, we studied liver mitochondrial respiratory chain activities in two patients and revealed a combined defect of several complexes. In addition, we retrospectively analyzed methionine plasma concentration, a hallmark of ADK deficiency, in a cohort of children and showed that methionine level in patients with ADK deficiency was strongly increased compared with patients with other liver diseases. ADK deficiency is a cause of neonatal or early infantile liver disease that may mimic primary mitochondrial disorders. In this context, an elevation of methionine plasma levels over twice the upper limit should not be considered as a nonspecific finding. ADK deficiency induced-liver dysfunction is most often transient, but could be life-threatening.