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

BACKGROUND 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 accuracy of serum MMP-7 as a diagnostic biomarker in a large North American cohort. APPROACH RESULTS: MMP-7 was measured in serum samples of 399 cholestatic infants 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 (TR-FRET) assays. Discriminative performance of MMP-7 was compared with other clinical markers. On the single-plex assay, MMP-7 generated an area under receiver operating curve (AUROC) of 0.90 (confidence interval [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 (GGT)=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+GGT AUROC to 0.91 (CI 0.88-0.95). Serum concentrations produced by TR-FRET differed from single-plex, with 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 evaluation of cholestatic infants may simplify diagnostic algorithms and shorten time to hepatoportoenterostomy.

Neonatal cholestasis in children with Alpha-1-AT deficiency is a risk for earlier severe liver disease with male predominance.

BACKGROUND: Our objective was to better understand the natural history and disease modifiers of Alpha-1-antitrypsin deficiency (AATD), a common genetic liver disease causing hepatitis and cirrhosis in adults and children. The clinical course is highly variable. Some infants present with neonatal cholestasis, which can resolve spontaneously or progress to cirrhosis; others are well in infancy, only to develop portal hypertension later in childhood. METHODS: The Childhood Liver Disease Research Network has been enrolling AATD participants into longitudinal, observational studies at North American tertiary centers since 2004. We examined the clinical courses of 2 subgroups of participants from the several hundred enrolled; first, those presenting with neonatal cholestasis captured by a unique study, enrolled because of neonatal cholestasis but before specific diagnosis, then followed longitudinally (n=46); second, separately, all participants who progressed to liver transplant (n=119). RESULTS: We found male predominance for neonatal cholestasis in AATD (65% male, p=0.04), an association of neonatal gamma-glutamyl transpeptidase elevation to more severe disease, and a higher rate of neonatal cholestasis progression to portal hypertension than previously reported (41%) occurring at median age of 5 months. Participants with and without preceding neonatal cholestasis were at risk of progression to transplant. Participants who progressed to liver transplant following neonatal cholestasis were significantly younger at transplant than those without neonatal cholestasis (4.1 vs. 7.8 years, p=0.04, overall range 0.3-17 years). Neonatal cholestasis had a negative impact on growth parameters. Coagulopathy and varices were common before transplant, but gastrointestinal bleeding was not. CONCLUSIONS: Patients with AATD and neonatal cholestasis are at risk of early progression to severe liver disease, but the risk of severe disease extends throughout childhood. Careful attention to nutrition and growth is needed.

A Gastroenterologist's Guide to Care Transitions in Cystic Fibrosis from Pediatrics to Adult Care.

Cystic Fibrosis is a chronic disease affecting multiple systems, including the GI tract. Clinical manifestation in patients can start as early as infancy and vary across different age groups. With the advent of new, highly effective modulators, the life expectancy of PwCF has improved significantly. Various GI aspects of CF care, such as nutrition, are linked to an overall improvement in morbidity, lung function and the quality of life of PwCF. The variable clinical presentations and management of GI diseases in pediatrics and adults with CF should be recognized. Therefore, it is necessary to ensure efficient transfer of information between pediatric and adult providers for proper continuity of management and coordination of care at the time of transition. The transition of care is a challenging process for both patients and providers and currently there are no specific tools for GI providers to help ensure a smooth transition. In this review, we aim to highlight the crucial features of GI care at the time of transition and provide a checklist that can assist in ensuring an effective transition and ease the challenges associated with it.

Sarcopenia is associated with osteopenia and impaired quality of life in children with genetic intrahepatic cholestatic liver disease.

BACKGROUND: Sarcopenia occurs in pediatric chronic liver disease, although the prevalence and contributing factors in genetic intrahepatic cholestasis are not well-described. The objective of this study was to measure muscle mass in school-aged children with genetic intrahepatic cholestasis and assess relationships between sarcopenia, clinical variables, and outcomes. METHODS: Estimated skeletal muscle mass (eSMM) was calculated on dual-energy x-ray absorptiometry obtained in a Childhood Liver Disease Research Network study of children with bile acid synthesis disorders(BASD) alpha-1 antitrypsin deficiency (a1ATd), chronic intrahepatic cholestasis (CIC), and Alagille syndrome (ALGS). Relationships between eSMM, liver disease, and transplant-free survival were assessed. RESULTS: eSMM was calculated in 127 participants (5-18 y): 12 BASD, 41 a1ATd, 33 CIC, and 41 ALGS. eSMM z-score was lower in CIC (-1.6 ± 1.3) and ALGS (-2.1 ± 1.0) than BASD (-0.1 ± 1.1) and a1ATd (-0.5 ± 0.8, p < 0.001). Sarcopenia (defined as eSMM z-score ≤- 2) was present in 33.3% of CIC and 41.5% of ALGS participants. eSMM correlated with bone mineral density in the 4 disease groups (r=0.52-0.55, p < 0.001-0.07), but not serum bile acids, bilirubin, aspartate aminotransferase/platelet ratio index, or clinically evident portal hypertension. Of the 2 patients who died (1 with sarcopenia) and 18 who underwent liver transplant (LT, 4 with sarcopenia), eSMM z-score did not predict transplant-free survival. eSMM z-score correlated with the Physical Pediatric Quality of Life Inventory score (r=0.38-0.53, p = 0.007-0.04) in CIC and a1ATd. CONCLUSION: Severe sarcopenia occurs in some children with ALGS and CIC. The lack of correlation between eSMM and biochemical cholestasis suggests mechanisms beyond cholestasis contribute to sarcopenia. While sarcopenia did not predict transplant-free survival, LT and death were infrequent events. Future studies may define mechanisms of sarcopenia in genetic intrahepatic cholestasis.

Change in Health-Related Quality of Life in Youth with Chronic Hepatitis B Living in North America: A 5-Year Cohort Study.

BACKGROUND: Greater hepatitis-related symptomology is associated with lower health-related quality-of-life (HRQoL) among untreated youth with chronic hepatitis B (CHB). How HRQoL changes over time in this population is unknown. METHODS: Children from 7 hepatology centers in North America positive for hepatitis B surface antigen, not taking anti-viral therapy, were enrolled in the Hepatitis B Research Network. A validated self-report HRQoL measure, the Child Health Questionnaire Child Report (CHQ-CF87), was completed annually by participants 10-17 years, with demographic variables, liver disease symptoms, and laboratory tests. Linear mixed-effects models were used to evaluate the 10 CHQ-CF87 subscale scores over 5 years among participants who completed the CHQ-CF87 at least twice. RESULTS: Participants (N = 174) completed the CHQ-CF87 a median of 4 times. Median age was 12 years (interquartile range: 10-14) at baseline; 60% were female, 79% Asian, and 47% adopted. The CHQ-CF87 subscale scores were high at baseline (median range: 75.4-100) and did not differ by time point, except for the Family Activities subscale (mean [95% CI]: 82.3 [79.8-84.8] at baseline; 90.8 [86.1-94.6] week 240). Most subscale scores lacked sufficient individual-level variability in change over time to evaluate predictors. Being White versus Asian predicted a more favorable change in Behavior (6.5 [95% CI: 2.0-11.0]). Older age predicted less favorable change in Mental Health (-0.8 [95% CI: -1.36 to -0.23] per year). Changes in liver enzymes and hepatitis B antigens, DNA, or symptom count were not related to changes in these subscale scores. CONCLUSION: HRQoL was generally good and consistent across 5 years in youth with CHB.

Alpha-1 Antitrypsin Deficiency Liver Disease.

Liver disease in homozygous ZZ alpha-1 antitrypsin (AAT) deficiency occurs due to the accumulation of large quantities of AAT mutant Z protein polymers in the liver. The mutant Z protein folds improperly during biogenesis and is retained within the hepatocytes rather than appropriately secreted. These intracellular polymers trigger an injury cascade, which leads to liver injury. However, the clinical liver disease is highly variable and not all patients with this same homozygous ZZ genotype develop liver disease. Evidence suggests that genetic determinants of intracellular protein processing, among other unidentified genetic and environmental factors, likely play a role in liver disease susceptibility. Advancements made in development of new treatment strategies using siRNA technology, and other novel approaches, are promising, and multiple human liver disease trials are underway.

Novel NMP split liver model recapitulates human IRI and demonstrates ferroptosis modulators as a new therapeutic strategy.

BACKGROUND: Almost 9%of deceased donor livers are discarded as marginal donor livers (MDL) due to concern of severe ischemia reperfusion injury (IRI). Emerging data supports ferroptosis (iron regulated hepatocellular death) as an IRI driver, however lack of robust preclinical model limits therapeutic testing. In this manuscript we describe the development of a novel rigorous internal control system utilizing normothermic perfusion of split livers to test ferroptosis regulators modulating IRI. METHODS: Upon institutional approval, split human MDLs were placed on our normothermic perfusion machine, Perfusion Regulated Organ Therapeutics with Enhanced Controlled Testing (PROTECT), pumping arterial and portal blood. Experiment 1 compared right (UR) and left (UL) lobes to validate PROTECT. Experiment 2 assessed ferroptosis regulator Deferoxamine in Deferoxamine Agent Treated (DMAT) vs. No Agent Internal Control (NAIC) lobes. Liver serology, histology, and ferroptosis genes were assessed. RESULTS: Successful MDL perfusion validated PROTECT with no ALT or AST difference between UR and UL (∆ALT UR: 235, ∆ALT UL: 212; ∆AST UR: 576, ∆AST UL: 389). Liver injury markers increased in NAIC vs. DMAT (∆ALT NAIC: 586, ∆ALT DMAT: -405; ∆AST NAIC: 617, ∆AST DMAT: -380). UR and UL had similar expression of ferroptosis regulators RPL8,HO-1 and HIFα. Significantly decreased intrahepatic iron (p = .038), HO-1 and HIFα in DMAT (HO-1 NAIC: 6.93, HO-1 DMAT: 2.74; HIFαNAIC: 8.67, HIFαDMAT: 2.60)and no hepatocellular necrosis or immunohistochemical staining (Ki67/Cytokeratin-7) differences were noted. CONCLUSION: PROTECT demonstrates the therapeutic utility of a novel normothermic perfusion split liver system for drug discovery and rapid translatability of therapeutics, driving a paradigm change in organ recovery and transplant medicine. Our study using human livers, provides preliminary proof of concept for the novel role of ferroptosis regulators in driving IRI.

Liver disease with unknown etiology - have you ruled out alpha-1 antitrypsin deficiency?

Although a less well-known consequence of alpha-1 antitrypsin deficiency (AATD) liver disease is the second leading cause of death among patients with the condition. The alpha-1 antitrypsin (AAT) protein is produced by hepatocytes within the liver, which retain pathological variants of AAT instead of secreting the proteinase inhibitor into the systemic circulation. This intracellular retention is caused by inefficient folding and polymerization of mutant AAT and the accumulation of these AAT aggregates leads to diverse manifestations of liver disease, which can present differently in both children and adults. The progression from hepatocyte apoptosis to liver inflammation, fibrosis and cirrhosis, and liver failure is still not fully understood, but in older patients, liver disease can surpass lung disease as the principal cause of death. Liver function tests (LFTs) can measure plasma levels of liver enzymes to assess liver function but require careful interpretation. Non-invasive tests are being developed that can detect early liver disease, but liver biopsy is still the gold standard for assessing liver fibrosis once abnormal LFTs have been detected in a patient. Currently, there is no licensed treatment for AATD-related liver disease (intravenous AAT therapy is not indicated for this purpose), but liver transplantation is associated with positive outcomes and may even slow emphysema progression. Therefore, new strategies are being developed to address treatment of AATD-related liver disease, such as accelerating degradation of mutant AAT and assisting hepatocytes in the folding and secretion of mutant AAT, but these approaches remain at early stages of development.

Chronic Hepatitis Is Common and Often Untreated Among Children with Hepatitis B Infection in the United States and Canada.

OBJECTIVE: To determine the outcomes of chronic hepatitis B virus (HBV) infection in a large, prospectively studied cohort of children in the US and Canada. STUDY DESIGN: This was a prospective, observational study of children with chronic HBV enrolled in 7 clinical centers and evaluated at baseline, weeks 24 and 48, and annually thereafter, with analysis of demographic, clinical, physical examination, and blood test data. RESULTS: Among 362 children followed for a median of 4.2 years, elevated alanine aminotransferase (ALT) levels (>1 upper limit of normal) were present in 72% at last evaluation, including in 60% of children with loss of hepatitis B e antigen during follow-up and 70% of those who were hepatitis B e antigen negative at baseline. Significant ALT flares (male patients ≥400 U/L, female patients ≥350 U/L) occurred in 13 children. Of 129 children who fulfilled the American Association for the Study of Liver Diseases treatment criteria during follow-up, anti-HBV treatment was initiated in only 25. One child died (unrelated to liver disease), 1 developed cirrhosis, but no episodes of cirrhotic decompensation or hepatocellular carcinoma were observed. Decline in platelet count was inversely associated with ALT elevations. CONCLUSIONS: In a cohort of children with chronic HBV infection in the US and Canada, many children remained at risk of progressive liver disease due to active hepatitis, but major clinical outcomes such as cirrhosis, cancer, and death were rare. Many children who met criteria for treatment remained untreated.

Alpha-1 antitrypsin deficiency liver disease.

The clinical presentation of liver disease is highly variable in homozygous ZZ alpha-1 antitrypsin (AAT) deficiency, and not all patients with the homozygous ZZ genotype develop liver disease. Although not fully identified, there is likely a strong influence of genetic and environmental modifiers of the intracellular injury cascade and fibrotic response. Most ZZ children are well and remain undiagnosed. Of those who come to medical attention, the most common pediatric presentation is neonatal cholestatic hepatitis, sometimes referred to as "neonatal hepatitis syndrome". The gold standard for diagnosis of AAT deficiency is analysis of the AAT protein phenotype in the patient serum or the genotype of their DNA genome. Careful follow up of all diagnosed children is important. Heterozygotes for S and Z alleles of AAT (SZ) may develop progressive liver disease similar to ZZ patients and also require close monitoring. There is no specific treatment for AAT deficiency induced liver disease and current therapy remains supportive with management of complications. Rarely, patients require liver transplant and typically the patient outcomes are excellent. With improved understanding of liver injury mechanisms, new strategies for treatment are now being explored, including siRNA technology, molecules to modulate secretion, and enhancers of proteolysis.

Up-regulation of miR-34b/c by JNK and FOXO3 protects from liver fibrosis.

α1-Antitrypsin (AAT) deficiency is a common genetic disease presenting with lung and liver diseases. AAT deficiency results from pathogenic variants in the SERPINA1 gene encoding AAT and the common mutant Z allele of SERPINA1 encodes for Z α1-antitrypsin (ATZ), a protein forming hepatotoxic polymers retained in the endoplasmic reticulum of hepatocytes. PiZ mice express the human ATZ and are a valuable model to investigate the human liver disease of AAT deficiency. In this study, we investigated differential expression of microRNAs (miRNAs) between PiZ and control mice and found that miR-34b/c was up-regulated and its levels correlated with intrahepatic ATZ. Furthermore, in PiZ mouse livers, we found that Forkhead Box O3 (FOXO3) driving microRNA-34b/c (miR-34b/c) expression was activated and miR-34b/c expression was dependent upon c-Jun N-terminal kinase (JNK) phosphorylation on Ser574 Deletion of miR-34b/c in PiZ mice resulted in early development of liver fibrosis and increased signaling of platelet-derived growth factor (PDGF), a target of miR-34b/c. Activation of FOXO3 and increased miR-34c were confirmed in livers of humans with AAT deficiency. In addition, JNK-activated FOXO3 and miR-34b/c up-regulation were detected in several mouse models of liver fibrosis. This study reveals a pathway involved in liver fibrosis and potentially implicated in both genetic and acquired causes of hepatic fibrosis.

Outcomes of Childhood Cholestasis in Alagille Syndrome: Results of a Multicenter Observational Study.

Alagille syndrome (ALGS) is an autosomal dominant multisystem disorder with cholestasis as a defining clinical feature. We sought to characterize hepatic outcomes in a molecularly defined cohort of children with ALGS-related cholestasis. Two hundred and ninety-three participants with ALGS with native liver were enrolled. Participants entered the study at different ages and data were collected retrospectively prior to enrollment, and prospectively during the study course. Genetic analysis in 206 revealed JAGGED1 mutations in 91% and NOTCH2 mutations in 4%. Growth was impaired with mean height and weight z-scores of <-1.0 at all ages. Regression analysis revealed that every 10 mg/dL increase in total bilirubin was associated with a decrease in height z-score by 0.10 (P = 0.03) and weight z-score by 0.15 (P = 0.007). Total bilirubin was higher for younger participants (P = 0.03) with a median of 6.9 mg/dL for those less than 1 year old compared with a median of 1.3 mg/dL for participants 13 years or older. The median gamma glutamyl transferase also dropped from 612 to 268 in the same age groups. After adjusting for age, there was substantial within-individual variation of alanine aminotransferase. By 20 years of age, 40% of participants had developed definite portal hypertension. Estimated liver transplant-free survival at the age of 18.5 years was 24%. Conclusions: This is the largest multicenter natural history study of cholestasis in ALGS, demonstrating a previously underappreciated burden of liver disease with early profound cholestasis, a second wave of portal hypertension later in childhood, and less than 25% of patients reaching young adulthood with their native liver. These findings will promote optimization of ALGS management and development of clinically relevant endpoints for future therapeutic 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.

A Highly Phenotyped Open Access Repository of Alpha-1 Antitrypsin Deficiency Pluripotent Stem Cells.

Individuals with the genetic disorder alpha-1 antitrypsin deficiency (AATD) are at risk of developing lung and liver disease. Patient induced pluripotent stem cells (iPSCs) have been found to model features of AATD pathogenesis but only a handful of AATD patient iPSC lines have been published. To capture the significant phenotypic diversity of the patient population, we describe here the establishment and characterization of a curated repository of AATD iPSCs with associated disease-relevant clinical data. To highlight the utility of the repository, we selected a subset of iPSC lines for functional characterization. Selected lines were differentiated to generate both hepatic and lung cell lineages and analyzed by RNA sequencing. In addition, two iPSC lines were targeted using CRISPR/Cas9 editing to accomplish scarless repair. Repository iPSCs are available to investigators for studies of disease pathogenesis and therapeutic discovery.

Leveraging Population Genomics for Individualized Correction of the Hallmarks of Alpha-1 Antitrypsin Deficiency.

Deep medicine is rapidly moving towards a high-definition approach for therapeutic management of the patient as an individual given the rapid progress of genome sequencing technologies and machine learning algorithms. While considered a monogenic disease, alpha-1 antitrypsin (AAT) deficiency (AATD) patients present with complex and variable phenotypes we refer to as the "hallmarks of AATD" that involve distinct molecular mechanisms in the liver, plasma and lung tissues, likely due to both coding and non-coding variation as well as genetic and environmental modifiers in different individuals. Herein, we briefly review the current therapeutic strategies for the management of AATD. To embrace genetic diversity in the management of AATD, we provide an overview of the disease phenotypes of AATD patients harboring different AAT variants. Linking genotypic diversity to phenotypic diversity illustrates the potential for sequence-specific regions of AAT protein fold design to play very different roles during nascent synthesis in the liver and/or function in post-liver plasma and lung environments. We illustrate how to manage diversity with recently developed machine learning (ML) approaches that bridge sequence-to-function-to-structure knowledge gaps based on the principle of spatial covariance (SCV). SCV relationships provide a deep understanding of the genotype to phenotype transformation initiated by AAT variation in the population to address the role of genetic and environmental modifiers in the individual. Embracing the complexity of AATD in the population is critical for risk management and therapeutic intervention to generate a high definition medicine approach for the patient.

CHOP and c-JUN up-regulate the mutant Z α1-antitrypsin, exacerbating its aggregation and liver proteotoxicity.

α1-Antitrypsin (AAT) encoded by the SERPINA1 gene is an acute-phase protein synthesized in the liver and secreted into the circulation. Its primary role is to protect lung tissue by inhibiting neutrophil elastase. The Z allele of SERPINA1 encodes a mutant AAT, named ATZ, that changes the protein structure and leads to its misfolding and polymerization, which cause endoplasmic reticulum (ER) stress and liver disease through a gain-of-function toxic mechanism. Hepatic retention of ATZ results in deficiency of one of the most important circulating proteinase inhibitors and predisposes to early-onset emphysema through a loss-of-function mechanism. The pathogenetic mechanisms underlying the liver disease are not completely understood. C/EBP-homologous protein (CHOP), a transcription factor induced by ER stress, was found among the most up-regulated genes in livers of PiZ mice that express ATZ and in human livers of patients homozygous for the Z allele. Compared with controls, juvenile PiZ/Chop-/- mice showed reduced hepatic ATZ and a transcriptional response indicative of decreased ER stress by RNA-Seq analysis. Livers of PiZ/Chop-/- mice also showed reduced SERPINA1 mRNA levels. By chromatin immunoprecipitations and luciferase reporter-based transfection assays, CHOP was found to up-regulate SERPINA1 cooperating with c-JUN, which was previously shown to up-regulate SERPINA1, thus aggravating hepatic accumulation of ATZ. Increased CHOP levels were detected in diseased livers of children homozygous for the Z allele. In summary, CHOP and c-JUN up-regulate SERPINA1 transcription and play an important role in hepatic disease by increasing the burden of proteotoxic ATZ, particularly in the pediatric population.

Longitudinal Outcomes in Young Patients with Alpha-1-Antitrypsin Deficiency with Native Liver Reveal that Neonatal Cholestasis is a Poor Predictor of Future Portal Hypertension.

OBJECTIVES: To identify predictors of portal hypertension, liver transplantation, and death in North American youth with alpha-1-antitrypsin (AAT) deficiency, and compare with patients with AAT deficiency elsewhere. STUDY DESIGN: The Childhood Liver Disease Research Network Longitudinal Observational Study of Genetic Causes of Intrahepatic Cholestasis is a prospective, cohort study of pediatric cholestatic liver diseases, including AAT deficiency, enrolling PIZZ and PISZ subjects 0-25 years of age seen since November 2007 at 17 tertiary care centers in the US and Canada. Data from standard-of-care baseline and annual follow-up visits were recorded from medical records, history, physical examination, and laboratory studies. Participants with portal hypertension were identified based on data collected. RESULTS: We enrolled 350 participants (60% male) with a native liver; 278 (79%) entered the cohort without portal hypertension and 18 developed portal hypertension during follow-up. Thirty participants required liver transplantation; 2 patients died during 1077 person-years of follow-up. There was no difference in participants with or without preceding neonatal cholestasis progressing to transplantation or death during the study (12% vs 7%; P = .09), or in experiencing portal hypertension (28% vs 21%; P = .16); the hazard ratio for neonatal cholestasis leading to portal hypertension was P = .04. Development of portal hypertension was associated with a reduced height Z-score. CONCLUSIONS: Portal hypertension in youth with AAT deficiency impacts growth measures. Progression to liver transplantation is slow and death is rare, but the risk of complications and severe liver disease progression persists throughout childhood. A history of neonatal cholestasis is a weak predictor of severe disease.

Development of an RNAi therapeutic for alpha-1-antitrypsin liver disease.

The autosomal codominant genetic disorder alpha-1 antitrypsin (AAT) deficiency (AATD) causes pulmonary and liver disease. Individuals homozygous for the mutant Z allele accumulate polymers of Z-AAT protein in hepatocytes, where AAT is primarily produced. This accumulation causes endoplasmic reticulum (ER) stress, oxidative stress, damage to mitochondria, and inflammation, leading to fibrosis, cirrhosis, and hepatocellular carcinoma. The magnitude of AAT reduction and duration of response from first-generation intravenously administered RNA interference (RNAi) therapeutic ARC-AAT and then with next-generation subcutaneously administered ARO-AAT were assessed by measuring AAT protein in serum of the PiZ transgenic mouse model and human volunteers. The impact of Z-AAT reduction by RNAi on liver disease phenotypes was evaluated in PiZ mice by measuring polymeric Z-AAT in the liver; expression of genes associated with fibrosis, autophagy, apoptosis, and redox regulation; inflammation; Z-AAT globule parameters; and tumor formation. Ultrastructure of the ER, mitochondria, and autophagosomes in hepatocytes was evaluated by electron microscopy. In mice, sustained RNAi treatment reduced hepatic Z-AAT polymer, restored ER and mitochondrial health, normalized expression of disease-associated genes, reduced inflammation, and prevented tumor formation. RNAi therapy holds promise for the treatment of patients with AATD-associated liver disease. ARO-AAT is currently in phase II/III clinical trials.

Detection of alpha-1 antitrypsin deficiency: the past, present and future.

BACKGROUND: Most patients with alpha-1 antitrypsin deficiency remain undiagnosed and therefore do not benefit from current therapies or become eligible for research studies of new treatments under development. Improving the detection rate for AATD is therefore a high priority for the Alpha-1 Foundation. A workshop was held on June 23, 2019 in Orlando, Florida during which stakeholders from the research, pharmaceutical, and patient communities focused on the topic of alpha-1 antitrypsin deficiency detection. RESULTS: A variety of detection strategies have been explored in the past and new approaches are emerging as technology advances. Targeted detection includes patients with chronic obstructive pulmonary disease, unexplained chronic liver disease, and family members of affected individuals. Newborn screening, electronic medical record data mining, and direct-to-consumer testing remain options for future detection strategies. CONCLUSION: These meeting proceedings can serve as a basis for innovative approaches to the detection of alpha-1 antitrypsin deficiency.

Hepatic Histology in Treatment-naïve Children With Chronic Hepatitis B Infection Living in the United States and Canada.

OBJECTIVES: Chronic hepatitis B virus infection is a major cause of morbidity and mortality. The aim of the study is to describe the hepatic histology in children chronically infected with hepatitis B virus living in the United States and Canada. METHODS: Liver biopsies of 134 treatment-naïve children with chronic hepatitis B virus infection were scored for inflammation, fibrosis, and other histological features, and correlated with clinical and laboratory data. RESULTS: Sixty percentage of subjects acquired the infection vertically, 51% were male, and 69% were hepatitis B e antigen-positive at the time of the biopsy. Hepatitis B DNA levels were generally high (mean 7.70 log IU/mL), as was serum alanine aminotransferase (median 120 U/L). Using the Ishak-modified histology activity index scoring system, interface hepatitis was mild in 31%, moderate in 61%, and severe in 6%. Lobular inflammation was mild in 54%, moderate in 29%, and marked in 7%. Portal inflammation was mild in 38% and moderate in 62% of subjects. Eighteen percentage had no fibrosis, 59% had portal expansion without bridging fibrosis, 19% had bridging fibrosis, and 4% had cirrhosis. Alanine aminotransferase positively correlated with inflammation and fibrosis. Neither age, duration of infection, nor Hepatitis B virus DNA levels correlated with fibrosis. Fibrosis-4 index did not correlate with fibrosis but correlated with inflammation. Aspartate aminotransferase/platelet ratio index correlated with both inflammation and fibrosis. CONCLUSIONS: Chronic hepatitis B virus infection results in significant inflammation and fibrosis during childhood. Serum alanine aminotransferase is a strong indicator of the severity and extent of hepatic inflammation and fibrosis.