Diagnostic accuracy of serum matrix metalloproteinase-7 as a biomarker of biliary atresia in a large North American cohort.

BACKGROUND AND AIMS: High levels of serum matrix metalloproteinase-7 (MMP-7) have been linked to biliary atresia (BA), with wide variation in concentration cutoffs. We investigated the accuracy of serum MMP-7 as a diagnostic biomarker in a large North American cohort. APPROACH AND RESULTS: MMP-7 was measured in serum samples of 399 infants with cholestasis in the Prospective Database of Infants with Cholestasis study of the Childhood Liver Disease Research Network, 201 infants with BA and 198 with non-BA cholestasis (age median: 64 and 59 days, p = 0.94). MMP-7 was assayed on antibody-bead fluorescence (single-plex) and time resolved fluorescence energy transfer assays. The discriminative performance of MMP-7 was compared with other clinical markers. On the single-plex assay, MMP-7 generated an AUROC of 0.90 (CI: 0.87-0.94). At cutoff 52.8 ng/mL, it produced sensitivity = 94.03%, specificity = 77.78%, positive predictive value = 64.46%, and negative predictive value = 96.82% for BA. AUROC for gamma-glutamyl transferase = 0.81 (CI: 0.77-0.86), stool color = 0.68 (CI: 0.63-0.73), and pathology = 0.84 (CI: 0.76-0.91). Logistic regression models of MMP-7 with other clinical variables individually or combined showed an increase for MMP-7+gamma-glutamyl transferase AUROC to 0.91 (CI: 0.88-0.95). Serum concentrations produced by time resolved fluorescence energy transfer differed from single-plex, with an optimal cutoff of 18.2 ng/mL. Results were consistent within each assay technology and generated similar AUROCs. CONCLUSIONS: Serum MMP-7 has high discriminative properties to differentiate BA from other forms of neonatal cholestasis. MMP-7 cutoff values vary according to assay technology. Using MMP-7 in the evaluation of infants with cholestasis may simplify diagnostic algorithms and shorten the time to hepatoportoenterostomy.

Clinical spectrum and genetic causes of mitochondrial hepatopathy phenotype in children.

BACKGROUND: Alterations in both mitochondrial DNA (mtDNA) and nuclear DNA genes affect mitochondria function, causing a range of liver-based conditions termed mitochondrial hepatopathies (MH), which are subcategorized as mtDNA depletion, RNA translation, mtDNA deletion, and enzymatic disorders. We aim to enhance the understanding of pathogenesis and natural history of MH. METHODS: We analyzed data from patients with MH phenotypes to identify genetic causes, characterize the spectrum of clinical presentation, and determine outcomes. RESULTS: Three enrollment phenotypes, that is, acute liver failure (ALF, n = 37), chronic liver disease (Chronic, n = 40), and post-liver transplant (n = 9), were analyzed. Patients with ALF were younger [median 0.8 y (range, 0.0, 9.4) vs 3.4 y (0.2, 18.6), p < 0.001] with fewer neurodevelopmental delays (40.0% vs 81.3%, p < 0.001) versus Chronic. Comprehensive testing was performed more often in Chronic than ALF (90.0% vs 43.2%); however, etiology was identified more often in ALF (81.3% vs 61.1%) with mtDNA depletion being most common (ALF: 77% vs Chronic: 41%). Of the sequenced cohort (n = 60), 63% had an identified mitochondrial disorder. Cluster analysis identified a subset without an underlying genetic etiology, despite comprehensive testing. Liver transplant-free survival was 40% at 2 years (ALF vs Chronic, 16% vs 65%, p < 0.001). Eighteen (21%) underwent transplantation. With 33 patient-years of follow-up after the transplant, 3 deaths were reported. CONCLUSIONS: Differences between ALF and Chronic MH phenotypes included age at diagnosis, systemic involvement, transplant-free survival, and genetic etiology, underscoring the need for ultra-rapid sequencing in the appropriate clinical setting. Cluster analysis revealed a group meeting enrollment criteria but without an identified genetic or enzymatic diagnosis, highlighting the need to identify other etiologies.

Plasticity between type 2 innate lymphoid cell subsets and amphiregulin expression regulates epithelial repair in biliary atresia.

BACKGROUND AND AIMS: Although a dysregulated type 1 immune response is integral to the pathogenesis of biliary atresia, studies in both humans and mice have uncovered a type 2 response, primarily driven by type 2 innate lymphoid cells. In nonhepatic tissues, natural type 2 innate lymphoid cell (nILC2s) regulate epithelial proliferation and tissue repair, whereas inflammatory ILC2s (iIlC2s) drive tissue inflammation and injury. The aim of this study is to determine the mechanisms used by type 2 innate lymphoid cell (ILC2) subpopulations to regulate biliary epithelial response to an injury. APPROACH AND RESULTS: Using Spearman correlation analysis, nILC2 transcripts, but not those of iILC2s, are positively associated with cholangiocyte abundance in biliary atresia patients at the time of diagnosis. nILC2s are identified in the mouse liver through flow cytometry. They undergo expansion and increase amphiregulin production after IL-33 administration. This drives epithelial proliferation dependent on the IL-13/IL-4Rα/STAT6 pathway as determined by decreased nILC2s and reduced epithelial proliferation in knockout strains. The addition of IL-2 promotes inter-lineage plasticity towards a nILC2 phenotype. In experimental biliary atresia induced by rotavirus, this pathway promotes epithelial repair and tissue regeneration. The genetic loss or molecular inhibition of any part of this circuit switches nILC2s to inflammatory type 2 innate lymphoid cell-like, resulting in decreased amphiregulin production, decreased epithelial proliferation, and the full phenotype of experimental biliary atresia. CONCLUSIONS: These findings identify a key function of the IL-13/IL-4Rα/STAT6 pathway in ILC2 plasticity and an alternate circuit driven by IL-2 to promote nILC2 stability and amphiregulin expression. This pathway induces epithelial homeostasis and repair in experimental biliary atresia.

Recent Increase in Incidence of Severe Acute Hepatitis of Unknown Etiology in Children is Associated with Infection with Adenovirus and Other Nonhepatotropic Viruses.

OBJECTIVE: To evaluate whether the nature and severity of non-A-E severe acute hepatitis in children noted by the World Health Organization from late 2021 through early 2022 was indeed increased in 2021-2022 compared with prior years. STUDY DESIGN: We performed a single-center, retrospective study to track the etiology and outcomes of children with non-A-E severe acute hepatitis in 2021-2022 compared with the prior 3-year periods (2018-2019, 2019-2020, and 2020-2021). We queried electronic medical records of children ≤16 years of age with alanine or aspartate aminotransferase levels of >500 IU. Data were analyzed for the periods of October 1, 2021, to May 1, 2022, and compared with the same time periods in 2018-2021. RESULTS: Of 107 children meeting entry criteria, 82 cases occurred from October to May of 2018-2022. The average annual case number was 16.3 in 2018-2021 compared with a 2-fold increase (to 33) in 2021-2022 (P = .0054). Analyses of etiologies showed that this increase was associated with a higher number of children who tested positive for viruses (n = 16) when compared with the average of 3.7 for 2018-2021 (P = .018). Adenovirus (26.1%) and severe acute respiratory syndrome coronavirus-2 (10.3%) were the most frequently detected viruses in 2021-2022. Despite evidence of acute liver failure in 37.8% of children in the entire cohort and in 47% of those with viral infection, the overall survival rate was high at 91.4% and 88.9%, respectively. CONCLUSIONS: The number of children with severe acute hepatitis in our center increased from 2021 to May 2022, with a greater frequency of cases associated with adenovirus, yet transplant-free survival remains high.

Customized Postoperative Therapy Improves Bile Drainage in Biliary Atresia: A Single Center Preliminary Report.

BACKGROUND: Controversies in management of biliary atresia (BA) after hepatoportoenterostomy (HPE) lead to variable treatment protocols. We implemented standardized medical management after HPE, customizing the use of antibiotics and corticosteroids based on patient-specific factors. METHODS: In this retrospective analysis, 20 consecutive infants underwent HPE for BA and were compared to a historical cohort. Analysis of successful biliary drainage 3 months after HPE (defined as serum total bilirubin <2 mg/dL) was the primary endpoint; survival with native liver at 2 years was the secondary endpoint. RESULTS: Sixteen of 20 (80%) infants had successful bile drainage, compared to 8 of 20 (40%) infants in the historical cohort (P = 0.0225). Sixteen of 20 patients in the new protocol have reached 2 years of age or required liver transplantation. Among the sixteen, 11 (68.8%) are alive with native livers versus 10 of 20 (50%) in the historical cohort (P = 0.0970). CONCLUSION: This preliminary report suggests the potential benefit of tailored use of postoperative antibiotics and corticosteroids in improving biliary drainage after HPE. LEVEL OF EVIDENCE: III.

Serum biomarkers correlated with liver stiffness assessed in a multicenter study of pediatric cholestatic liver disease.

BACKGROUND AND AIMS: Detailed investigation of the biological pathways leading to hepatic fibrosis and identification of liver fibrosis biomarkers may facilitate early interventions for pediatric cholestasis. APPROACH AND RESULTS: A targeted enzyme-linked immunosorbent assay-based panel of nine biomarkers (lysyl oxidase, tissue inhibitor matrix metalloproteinase (MMP) 1, connective tissue growth factor [CTGF], IL-8, endoglin, periostin, Mac-2-binding protein, MMP-3, and MMP-7) was examined in children with biliary atresia (BA; n = 187), alpha-1 antitrypsin deficiency (A1AT; n = 78), and Alagille syndrome (ALGS; n = 65) and correlated with liver stiffness (LSM) and biochemical measures of liver disease. Median age and LSM were 9 years and 9.5 kPa. After adjusting for covariates, there were positive correlations among LSM and endoglin ( p = 0.04) and IL-8 ( p < 0.001) and MMP-7 ( p < 0.001) in participants with BA. The best prediction model for LSM in BA using clinical and lab measurements had an R2 = 0.437; adding IL-8 and MMP-7 improved R2 to 0.523 and 0.526 (both p < 0.0001). In participants with A1AT, CTGF and LSM were negatively correlated ( p = 0.004); adding CTGF to an LSM prediction model improved R2 from 0.524 to 0.577 ( p = 0.0033). Biomarkers did not correlate with LSM in ALGS. A significant number of biomarker/lab correlations were found in participants with BA but not those with A1AT or ALGS. CONCLUSIONS: Endoglin, IL-8, and MMP-7 significantly correlate with increased LSM in children with BA, whereas CTGF inversely correlates with LSM in participants with A1AT; these biomarkers appear to enhance prediction of LSM beyond clinical tests. Future disease-specific investigations of change in these biomarkers over time and as predictors of clinical outcomes will be important.

Serum bile acids as a prognostic biomarker in biliary atresia following Kasai portoenterostomy.

BACKGROUND AND AIMS: In biliary atresia, serum bilirubin is commonly used to predict outcomes after Kasai portoenterostomy (KP). Infants with persistently high levels invariably need liver transplant, but those achieving normalized levels have a less certain disease course. We hypothesized that serum bile acid levels could help predict outcomes in the latter group. APPROACH AND RESULTS: Participants with biliary atresia from the Childhood Liver Disease Research Network were included if they had normalized bilirubin levels 6 months after KP and stored serum samples from the 6-month post-KP clinic visit ( n  = 137). Bile acids were measured from the stored serum samples and used to divide participants into ≤40 µmol/L ( n  = 43) or >40 µmol/L ( n  = 94) groups. At 2 years of age, the ≤40 µmol/L compared with >40 µmol/L group had significantly lower total bilirubin, aspartate aminotransferase, alanine aminotransferase, gamma-glutamyltransferase, bile acids, and spleen size, as well as significantly higher albumin and platelet counts. Furthermore, during 734 person-years of follow-up, those in the ≤40 µmol/L group were significantly less likely to develop splenomegaly, ascites, gastrointestinal bleeding, or clinically evident portal hypertension. The ≤40 µmol/L group had a 10-year cumulative incidence of liver transplant/death of 8.5% (95% CI: 1.1%-26.1%), compared with 42.9% (95% CI: 28.6%-56.4%) for the >40 µmol/L group ( p  = 0.001). CONCLUSIONS: Serum bile acid levels may be a useful prognostic biomarker for infants achieving normalized bilirubin levels after KP.

Use of funded multicenter prospective longitudinal databases to inform clinical trials in rare diseases-Examination of cholestatic liver disease in Alagille syndrome.

The conduct of long-term conventional randomized clinical trials in rare diseases is very difficult, making evidenced-based drug development problematic. As a result, real-world data/evidence are being used more frequently to assess new therapeutic approaches in orphan diseases. In this investigation, inclusion and exclusion criteria from a published trial of maralixibat in Alagille syndrome (ALGS, ITCH NCT02057692) were applied to a prospective longitudinal cohort of children with cholestasis (LOGIC NCT00571272) to derive contextual comparator data for evolving clinical trials of intestinal bile acid transport inhibitors in ALGS. A natural history/clinical care cohort of 59 participants who met adapted inclusion and exclusion criteria of ITCH was identified from 252 LOGIC participants with ALGS with their native liver. Frequency weighting was used to match the age distribution of ITCH and yielded a cohort (Alagille Syndrome Natural History [ALGS NH]) that was very similar to the baseline status of ITCH participants. During a 2-year prospective follow-up there was a significant reduction in pruritus in the weighted ALGS NH cohort as assessed by the clinician scratch score (-1.43 [0.28] -1.99, -0.87; mean [SEM] 95% confidence interval). During the same time period, the total bilirubin, albumin, and alanine aminotransferase levels were unchanged, whereas platelet count dropped significantly (-65.2 [16.2] -98.3, -32.1). Weighted survival with native liver was 91% at 2 years in the ALGS NH. These investigations provide valuable real-world data that can serve as contextual comparators to current clinical trials, especially those without control populations, and highlight the value and importance of funded multicenter, prospective, natural history studies.

The Liver Biopsy in Neonatal Cholestasis: Just a Cherry on Top?

Content available: Author Audio Recording.

Maternal regulation of biliary disease in neonates via gut microbial metabolites.

Maternal seeding of the microbiome in neonates promotes a long-lasting biological footprint, but how it impacts disease susceptibility in early life remains unknown. We hypothesized that feeding butyrate to pregnant mice influences the newborn's susceptibility to biliary atresia, a severe cholangiopathy of neonates. Here, we show that butyrate administration to mothers renders newborn mice resistant to inflammation and injury of bile ducts and improves survival. The prevention of hepatic immune cell activation and survival trait is linked to fecal signatures of Bacteroidetes and Clostridia and increases glutamate/glutamine and hypoxanthine in stool metabolites of newborn mice. In human neonates with biliary atresia, the fecal microbiome signature of these bacteria is under-represented, with suppression of glutamate/glutamine and increased hypoxanthine pathways. The direct administration of butyrate or glutamine to newborn mice attenuates the disease phenotype, but only glutamine renders bile duct epithelial cells resistant to cytotoxicity by natural killer cells. Thus, maternal intake of butyrate influences the fecal microbial population and metabolites in newborn mice and the phenotypic expression of experimental biliary atresia, with glutamine promoting survival of bile duct epithelial cells.

Biliary organoids uncover delayed epithelial development and barrier function in biliary atresia.

BACKGROUND AND AIMS: Biliary atresia is a severe inflammatory and fibrosing cholangiopathy of neonates of unknown etiology. The onset of cholestasis at birth implies a prenatal onset of liver dysfunction. Our aim was to investigate the mechanisms linked to abnormal cholangiocyte development. APPROACH AND RESULTS: We generated biliary organoids from liver biopsies of infants with biliary atresia and normal and diseased controls. Organoids emerged from biliary atresia livers and controls and grew as lumen-containing spheres with an epithelial lining of cytokeratin-19pos albuminneg SOX17neg cholangiocyte-like cells. Spheres had similar gross morphology in all three groups and expressed cholangiocyte-enriched genes. In biliary atresia, cholangiocyte-like cells lacked a basal positioning of the nucleus, expressed fewer developmental and functional markers, and displayed misorientation of cilia. They aberrantly expressed F-actin, ß-catenin, and Ezrin, had low signals for the tight junction protein zonula occludens-1 (ZO-1), and displayed increased permeability as evidenced by a higher Rhodamine-123 (R123) signal inside organoids after verapamil treatment. Biliary atresia organoids had decreased expression of genes related to EGF signaling and FGF2 signaling. When treated with EGF+FGF2, biliary atresia organoids expressed differentiation (cytokeratin 7 and hepatocyte nuclear factor 1 homeobox B) and functional (somatostatin receptor 2, cystic fibrosis transmembrane conductance regulator [CFTR], aquaporin 1) markers, restored polarity with improved localization of F-actin, ß-catenin and ZO-1, increased CFTR function, and decreased uptake of R123. CONCLUSIONS: Organoids from biliary atresia are viable and have evidence of halted epithelial development. The induction of developmental markers, improved cell-cell junction, and decreased epithelial permeability by EGF and FGF2 identifies potential strategies to promote epithelial maturation and function.

Serum Proteomics Uncovers Biomarkers of Clinical Portal Hypertension in Children With Biliary Atresia.

Children with biliary atresia (BA) often develop portal hypertension (PHT) and its complications, which are associated with high morbidity and mortality. The goal of this study was to identify serum biomarkers of PHT by using large-scale proteomics. We applied the slow off-rate modified aptamer scan (SOMAscan) to measure 1,305 proteins in serum samples of children with BA with and without clinical evidence of PHT in validation and discovery cohorts enrolled in the Biliary Atresia Study of Infants and Children. Serum proteomics data was analyzed using logistic regression to identify protein(s) with an area under the receiver operating characteristic curve (AUROC) ≥ 0.90. Immunostaining was used to characterize the cellular localization of the new biomarker proteins in liver tissues. We identified nine proteins in the discovery cohort (n = 40 subjects) and five proteins in the validation cohort (n = 80 subjects) that individually or in combination predicted clinical PHT with AUROCs ≥ 0.90. Merging the two cohorts, we found that semaphorin 6B (SEMA6B) alone and three other protein combinations (SEMA6B+secreted frizzle protein 3 [SFRP3], SEMA6B+COMM domain containing 7 [COMMD7], and vascular cell adhesion molecule 1 [VCAM1]+BMX nonreceptor tyrosine kinase [BMX]) had AUROCs ≥ 0.90 in both cohorts, with high positive- and negative-predictive values. Immunostaining of the new protein biomarkers showed increased expression in hepatic endothelial cells, cholangiocytes, and immune cells within portal triads in BA livers with clinical PHT compared to healthy livers. Conclusion: Large-scale proteomics identified SEMA6B, SFRP3, COMMD7, BMX, and VCAM1 as biomarkers highly associated with clinical PHT in BA. The expression of the biomarkers in hepatic epithelial, endothelial, and immune cells support their potential role in the pathophysiology of PHT.

Presentation and Outcomes of Infants With Idiopathic Cholestasis: A Multicenter Prospective Study.

OBJECTIVES: The aim of the study was to determine the frequency and natural history of infantile idiopathic cholestasis (IC) in a large, prospective, multicenter cohort of infants. METHODS: We studied 94 cholestatic infants enrolled up to 6 months of age in the NIDDK ChiLDReN (Childhood Liver Disease Research Network) "PROBE" protocol with a final diagnosis of IC; they were followed up to 30 months of age. RESULTS: Male sex (66/94; 70%), preterm birth (22/90 with data; 24% born at < 37 weeks' gestational age), and low birth weight (25/89; 28% born at <2500 g) were frequent, with no significant differences between outcomes. Clinical outcomes included death (n = 1), liver transplant (n = 1), biochemical resolution (total bilirubin [TB] ≤1 mg/dL and ALT < 35 U/L; n = 51), partial resolution (TB > 1 mg/dL and/or ALT > 35 U/L; n = 7), and exited healthy (resolved disease per study site report but without documented biochemical resolution; n = 34). Biochemical resolution occurred at median of 9 months of age. GGT was <100 U/L at baseline in 34 of 83 participants (41%). CONCLUSIONS: Frequency of IC and of death or liver transplant was less common in this cohort than in previously published cohorts, likely because of recent discovery and diagnosis of genetic etiologies of severe/persistent cholestasis that previously were labeled as idiopathic. Preterm birth and other factors associated with increased vulnerability in neonates are relatively frequent and may contribute to IC. Overall outcome in IC is excellent. Low/normal GGT was common, possibly indicating a role for variants in genes associated with low-GGT cholestasis-this warrants further study.

The 2020 Nobel Prize for Medicine or Physiology for the Discovery of Hepatitis C Virus: A Triumph of Curiosity and Persistence.

The 2020 Nobel Prize in Medicine or Physiology was awarded to Drs. Harvey Alter, Michael Houghton, and Charles Rice for their contributions to the discovery and characterization of the hepatitis C virus (HCV). Their achievements represent a remarkable triumph of biomedical science which allowed the development of curative therapy for HCV, that will save countless lives. This tribute provides a historical perspective of the laureates' seminal work leading to the discovery of the HCV and a synopsis of a forum hosted by the American Association for the Study of Liver Diseases to honor the laureates in which they offered their perspectives, advice for young investigators and what's left to accomplish in the field. Finally, others in the research community who have worked closely with one or more of the laureates, share some of their personal reflections and anecdotes.

Autoimmune Hepatitis: Predictors of Native Liver Survival in Children and Adolescents.

OBJECTIVE: To determine predictors of native liver survival (NLS) in children and adolescents with autoimmune hepatitis (AIH). STUDY DESIGN: The medical records of children and adolescents with AIH were reviewed. A questionnaire was used to collect data on clinical presentation, biochemical and histologic findings, and treatment. RESULTS: A total of 819 patients were included, 89.6% with AIH-1 and 10.4% with AIH-2. The median age (months) at onset was 108 (min 6; max 210; IQR 59). The female sex was predominant (75.8%). The overall survival was 93.0%, with an NLS of 89.9%; 4.6% underwent liver transplantation. The risk of death or liver transplantation during follow-up was 3.2 times greater in patients with AIH-1 (P = .024). Greater levels of aspartate aminotransferase, alanine aminotransferase, serum albumin, platelet, and normal international normalized ratio at the initial presentation were associated with longer NLS (P = .046, P = .006, P < .001, P = .001, and P = .019, respectively). Normal C3 levels was associated with longer NLS (P = .017), with a chance of death or liver transplantation during follow-up being 3.4 times greater in patients with C3 below normal. Death or liver transplantation during follow-up was 2.8 times greater in patients with associated sclerosing cholangitis (P = .046). Complete remission favored NLS (P < .001), with a risk of death or liver transplantation 11.7 times greater for patients not achieving remission. CONCLUSIONS: The best predictors of NLS in children and adolescents with AIH were the AIH-2 subtype, a normal C3 at diagnosis, remission during treatment, and normal a cholangiogram during the disease course.

Modeling Outcomes in Children With Biliary Atresia With Native Liver After 2 Years of Age.

Approximately 50% of infants with biliary atresia (BA) undergoing Kasai portoenterostomy show survival with native liver (SNL) at age 2 years. Predictors of disease progression after age 2 years are unknown, despite estimates of 20%-30% undergoing liver transplant (LT) between age 2 and 18 years. We sought to address this knowledge gap by developing prognostic models in participants of the multicenter prospective National Institutes of Health-supported Childhood Liver Disease Research Network. We extracted 14 clinical and biochemical variables at age 2 years to develop two models for future outcomes: 1) LT or death (LTD) and 2) first sentinel event (SE), either new onset ascites, hepatopulmonary syndrome (HPS), or gastrointestinal (GI) bleed. A total of 240 participants, enrolled between 2004 and 2017, were followed until a median age of 5.1 years (range, 2.0-13.3 years). Of these participants, 38 underwent LT (n = 37) or death (n = 1); cumulative incidence, 23.7% (95% confidence interval [CI], 16.2%-32.0%). Twenty-seven experienced either new-onset ascites (n = 13), HPS (n = 1), or GI bleed (n = 14). One participant had ascites and GI bleed concurrently; cumulative incidence, 21.5% (95% CI, 14.2%-29.8%) by age 10 years. The Cox proportional hazard model predicted risk of LTD, using total bilirubin, albumin, platelet count, and history of either ascites or cholangitis (BA LTD model), with a C-index of 0.88 (range, 0.86-0.89). A cause-specific hazard competing risk model predicted SE using platelet count and gamma glutamyltransferase levels (BA SE model) with a C-index of 0.81 (range, 0.80-0.84). Internal model validity was assessed using Harrell's C-index with cross-validation. Conclusion: Stratification using these models identified risk of poor outcomes in patients with BA SNL after age 2 years. The models may identify those who would benefit from enhanced clinical surveillance and prioritization in clinical trials.

Nonfasted Liver Stiffness Correlates with Liver Disease Parameters and Portal Hypertension in Pediatric Cholestatic Liver Disease.

Elastographic measurement of liver stiffness is of growing importance in the assessment of liver disease. Pediatric experiences with this technique are primarily single center and limited in scope. The Childhood Liver Disease Research Network provided a unique opportunity to assess elastography in a well-characterized multi-institutional cohort. Children with biliary atresia (BA), alpha-1 antitrypsin deficiency (A1ATD), or Alagille syndrome (ALGS) followed in a prospective longitudinal network study were eligible for enrollment in a prospective investigation of transient elastography (FibroScan). Studies were performed in participants who were nonfasted and nonsedated. Liver stiffness measurements (LSMs) were correlated with standard clinical and biochemical parameters of liver disease along with a research definition of clinically evident portal hypertension (CEPH) graded as absent, possible, or definite. Between November 2016 and August 2019, 550 participants with a mean age of 8.8 years were enrolled, 458 of whom had valid LSMs (BA, n = 254; A1ATD, n = 104; ALGS, n = 100). Invalid scans were more common in participants <2 years old. There was a positive correlation between LSM and total bilirubin, international normalized ratio (INR), aspartate aminotransferase (AST), alanine aminotransferase (ALT), gamma-glutamyl transpeptidase (GGT), GGT to platelet ratio (GPR), pediatric end-stage liver disease score, AST to platelet ratio index, and spleen size, and a negative correlation with albumin and platelet count in BA, with similar correlations for A1ATD (except AST, ALT, and albumin) and ALGS (except for INR, GGT, GPR, and ALT). Possible or definite CEPH was more common in BA compared to ALGS and A1ATD. LSM was greater in definite versus absent CEPH in all three diseases. Disease-specific clinical and biochemical characteristics of the different CEPH grades were observed. Conclusion: It is feasible to obtain LSMs in children, especially over the age of 2 years. LSM correlates with liver parameters and portal hypertension, although disease-specific patterns exist.

Natural Course of Pediatric Portal Hypertension.

The etiology of portal hypertension (pHTN) in children differs from that of adults and may require different management strategies. We set out to review the etiology, management, and natural history of pHTN at a pediatric liver center. From 2008 to 2018, 151 children and adolescents with pHTN were identified at a free-standing children's hospital. Patients were stratified by etiology of pHTN (intrahepatic disease [IH], defined as cholestatic disease and fibrotic or hepatocellular disease; extrahepatic disease [EH], defined as hepatic vein obstruction and prehepatic pHTN). Patients with EH were more likely to undergo an esophagoduodenscopy for a suspected gastrointestinal bleed (77% vs. 41%; P < 0.01). Surgical interventions differed based on etiology (P < 0.01), with IH more likely resulting in a transplant only (65%) and EH more likely to result in a shunt only (43%); 30% of patients with IH and 47% of patients with EH did not undergo an intervention for pHTN. Kaplan-Meier analysis revealed a significant increase in mortality in the group that received no intervention compared to shunt, transplant, or both and lower mortality in patients with prehepatic pHTN compared to other etiologies (P < 0.01 each). Multivariate analysis revealed increased odds of mortality in patients with refractory ascites (odds ratio [OR], 4.34; 95% confidence interval [CI], 1.00, 18.88; P = 0.05) and growth failure (OR, 13.49; 95% CI, 3.07, 58.99; P < 0.01). Conclusion: In this single institution study, patients with prehepatic pHTN had better survival and those who received no intervention had higher mortality than those who received an intervention. Early referral to specialized centers with experience managing these complex disease processes may allow for improved risk stratification and early intervention to improve outcomes.

Regulation of bile duct epithelial injury by hepatic CD71+ erythroid cells.

Extramedullary hematopoietic cells are present in the liver of normal neonates in the first few days of life and persist in infants with biliary atresia. Based on a previous report that liver genes are enriched by erythroid pathways, we examined the liver gene expression pattern at diagnosis and found the top 5 enriched pathways are related to erythrocyte pathobiology in children who survived with the native liver beyond 2 years of age. Using immunostaining, anti-CD71 antibodies identified CD71+ erythroid cells among extramedullary hematopoietic cells in the livers at the time of diagnosis. In mechanistic experiments, the preemptive antibody depletion of hepatic CD71+ erythroid cells in neonatal mice rendered them resistant to rhesus rotavirus-induced (RRV-induced) biliary atresia. The depletion of CD71+ erythroid cells increased the number of effector lymphocytes and delayed the RRV infection of livers and extrahepatic bile ducts. In coculture experiments, CD71+ erythroid cells suppressed the activation of hepatic mononuclear cells. These data uncover an immunoregulatory role for CD71+ erythroid cells in the neonatal liver.