Increased IgD and CD27 Double Negative (DN) B cell population in pediatric onset autoimmune hepatitis.

Autoimmune hepatitis (AIH) is a chronic, inflammatory liver disease of unknown aetiology which requires lifelong immunosuppression. Most therapeutic and outcome studies of AIH have been conducted predominantly in Caucasian (European Ancestry, EA) cohorts, with the exclusion of African American (AA) patients due to inadequate sample size. It is known that AA patients have a severe phenotype of autoimmune diseases and demonstrate a poor response to conventional medical therapy. Understanding cellular and molecular pathways which determine AIH severity and progression in AA patients is likely to lead to the discovery of novel, personalised and better tolerated therapies. The aim of the study is to determine the distinct effector B cell phenotypes which contribute to disease severity and progression of AIH in AA children as compared to their EA cohorts. PBMCs were isolated from blood samples collected from patients visiting Children's Healthcare of Atlanta (CHOA) and were grouped into AA, (n = 12), EA, (n = 11) and controls (n = 12) and were processed for flow cytometry. Markers of B cell development, maturation and activation were assessed namely CD19, CD21, IgD, CD27, CD38, CD11c, CD24, CD138. AA children with AIH demonstrated an expansion of CD19 + ve, Activated Naïve (aN), (CD19+ IgD-/CD27- Double Negative (DN2) ([CD19+/IgD-/CD27++CD38++) cells. Plasmablasts were significantly higher along with Signalling Lymphocytic activation molecule F7 (SLAMF7). Unswitched memory [CD19+] IgD+CD27+ (USM) B cells were significantly contracted in AA patients with AIH. B cell phenotyping reveals a distinct profile in AA AIH patients with a major skewing towards the expansion of effector pathways which have been previously characterised in severe SLE in AA patients. These results suggest that the quantification and therapeutic target of B cell pathway could contribute substantially to the clinical approach to AIH especially in the AA population.

Safety and Immunogenicity of Live Viral Vaccines in a Multicenter Cohort of Pediatric Transplant Recipients.

Importance: Live vaccines (measles-mumps-rubella [MMR] and varicella-zoster virus [VZV]) have not been recommended after solid organ transplant due to concern for inciting vaccine strain infection in an immunocompromised host. However, the rates of measles, mumps, and varicella are rising nationally and internationally, leaving susceptible immunocompromised children at risk for life-threating conditions. Objective: To determine the safety and immunogenicity of live vaccines in pediatric liver and kidney transplant recipients. Design, Setting, and Participants: This cohort study included select pediatric liver and kidney transplant recipients who had not completed their primary MMR and VZV vaccine series and/or who displayed nonprotective serum antibody levels at enrollment between January 1, 2002, and February 28, 2023. Eligibility for live vaccine was determined by individual US pediatric solid organ transplant center protocols. Exposures: Exposure was defined as receipt of a posttransplant live vaccine. Transplant recipients received 1 to 3 doses of MMR vaccine and/or 1 to 3 doses of VZV vaccine. Main Outcome and Measure: Safety data were collected following each vaccination, and antibody levels were obtained at 0 to 3 months and 1 year following vaccination. Comparisons were performed using Mann-Whitney U test, and factors associated with development of postvaccination protective antibodies were explored using univariate analysis. Results: The cohort included 281 children (270 [96%] liver, 9 [3%] kidney, 2 [1%] liver-kidney recipients) from 18 centers. The median time from transplant to enrollment was 6.3 years (IQR, 3.4-11.1 years). The median age at first posttransplant vaccine was 8.9 years (IQR, 4.7-13.8 years). A total of 202 of 275 (73%) children were receiving low-level monotherapy immunosuppression at the time of vaccination. The majority of children developed protective antibodies following vaccination (107 of 149 [72%] varicella, 130 of 152 [86%] measles, 100 of 120 [83%] mumps, and 124 of 125 [99%] rubella). One year post vaccination, the majority of children who initially mounted protective antibodies maintained this protection (34 of 44 [77%] varicella, 45 of 49 [92%] measles, 35 of 42 [83%] mumps, 51 of 54 [94%] rubella). Five children developed clinical varicella, all of which resolved within 1 week. There were no cases of measles or rubella and no episodes of graft rejection within 1 month of vaccination. There was no association between antibody response and immunosuppression level at the time of vaccination. Conclusions and Relevance: The findings suggest that live vaccinations may be safe and immunogenic after solid organ transplant in select pediatric recipients and can offer protection against circulating measles, mumps, and varicella.

Angiotensin-converting Enzyme-2 (ACE2) Expression in Pediatric Liver Disease.

The membrane protein angiotensin-converting enzyme-2 (ACE2) has gained notoriety as the receptor for severe acute respiratory syndrome coronavirus 2. Prior evidence has shown ACE2 is expressed within the liver but its function has not been fully discerned. Here, we utilized novel methodology to assess ACE2 expression in pediatric immune-mediated liver disease to better understand its presence in liver diseases and its role during infections such as COVID-19. We stained liver tissue with ACE2-specific immunofluorescent antibodies, analyzed via confocal microscopy. Computational deep learning-based segmentation models identified nuclei and cells, allowing the quantification of mean cellular and cytosolic immunofluorescent. Spatial transcriptomics provided high-throughput gene expression analysis in tissue to determine cellular composition for ACE2 expression. ACE2 plasma expression was quantified via enzyme-linked immunosorbent assay. High ACE2 expression was seen at the apical surface of cholangiocytes, with lower expression within hepatocyte cytosol and nonparenchymal cells ( P <0.001). Children with liver disease had higher ACE2 hepatic expression than pediatric control tissue ( P <0.001). Adult control tissue had higher expression than pediatric control ( P <0.001). Plasma ACE2 was not found to be statistically different between samples. Spatial transcriptomics identified cell composition of ACE2-expressing spots containing antibody-secreting cells. Our results show ACE2 expression throughout the liver, with strongest localization to cholangiocyte membranes. Machine learning can be used to rapidly identify hepatic cellular components for histologic analysis. ACE2 expression in the liver may be increased in pediatric liver disease. Future work is needed to better understand the role of ACE2 in chronic disease and acute infections.

Recent Insights into Pediatric Primary Sclerosing Cholangitis.

This article reviews recent literature on the pathogenesis, presentation, diagnosis, comorbidities, natural history, and management of pediatric primary sclerosing cholangitis (PSC). The authors shed light on the role of genetic and environmental factors in PSC, although recognize the limitations in the understanding of PSC pathogenesis. They reflect on presenting disease phenotypes, including the association with inflammatory bowel disease and frequent histologic presence of autoimmune hepatitis features. The current lack of effective medications is discussed, and disease complications and prognosis are described. Finally, the authors highlight available evidence while acknowledging the paucity of prospective pediatric data.

Education and Psychosocial Factors Predict Odds of Death After Transfer to Adult health Care in Pediatric Liver Transplant Patients.

OBJECTIVES: To analyze demographic, psychosocial, and clinical factors in pediatric liver transplant recipients for their association with death or loss to follow up in adulthood. We aimed to better understand known health disparities in transplant outcomes and identify potentially modifiable risk factors prior to transfer. METHODS: A retrospective cohort study of children who underwent liver transplantation at a large tertiary transplant center and were transferred to adult care between 2000 and 2015. RESULTS: During the study period, 101 qualifying patients were transferred. Ninety-three individuals followed with an adult provider, while 8 were lost to follow up. In total 23 of 93 patients died after transfer (24.7%). Several childhood factors were associated with adult death: Black race [odds ratio (OR) 6.59, P < 0.001]; psychiatric illness or substance use (OR 2.81, P = 0.04); failure to graduate high school before transfer (OR 9.59, P < 0.001); posttransplant tacrolimus medication-level variability index >2.5 (OR 5.36, P = 0.04); provider documentation of medication nonadherence (OR 4.72, P = 0.02); acute cellular rejection (OR 4.44, P = 0.03); the presence of diabetes mellitus (OR 5.71, P = 0.001), and chronic kidney disease (OR 2.82, P = 0.04). Failure to graduate HS was associated with loss to follow up ( P < 0.001). On multivariate analysis, Black race, substance use, diabetes, and failure to graduate HS retained association with adult death (each P < 0.05). CONCLUSIONS: Complex, intertwined patient characteristics are associated with increased odds of death in pediatric liver transplant recipients transferred to adult care. Early recognition of high-risk patients and intervention for modifiable factors, such as improved HS graduation and substance use prevention, may improve long-term outcomes.

Factors associated with improved patient and graft survival beyond 1 year in pediatric liver transplantation.

With advances in surgical techniques, medical management, and more equitable allocation systems, children who receive a liver transplantation (LT) today can expect remarkable outcomes early after LT. However, beyond 1 year after transplant, attrition rates have not improved. We reviewed two separate eras (Era 1: January 1995-June 2004 vs. Era 2: July 2004-March 2018) of the Society of Pediatric Liver Transplantation registry to explore the evolution and associated factors contributing to late graft loss (LGL) and late mortality (LM). The fraction of long-term pediatric LT recipients surviving after 1 year with their first graft significantly improved (81.5% in Era 1 vs. 85.7% in Era 2; p < 0.0001). This improvement occurred despite significant changes in patient selection toward higher risk populations (p < 0.001) and without notable improvement in perioperative complications such as hepatic artery thrombosis (p = 0.24) and early posttransplant reoperation (p = 0.94) that have historically contributed to poor late-allograft outcomes. Improved outcomes were associated with changes in patient characteristics and perioperative practices, which subsequently impacted both early post-LT complications as well as other sequalae known to contribute to adverse events in long-term pediatric LT recipients. In conclusion, despite significant changes in patient selection toward higher risk populations, and without notable improvement in several perioperative complications known to contribute to poor late-allograft outcomes, significant improvements in LGL and a trend toward improvement in LM was seen in a more contemporary cohort of children receiving an LT.

Predictors of survival following liver transplantation for pediatric hepatoblastoma and hepatocellular carcinoma: Experience from the Society of Pediatric Liver Transplantation (SPLIT).

Management of unresectable pediatric hepatoblastoma (HB) and hepatocellular carcinoma (HCC) remains challenging. The Society of Pediatric Liver Transplantation (SPLIT) database was used to study survival predictors in pediatric liver transplantation (LT) for HB and HCC. Event-free survival (EFS), associated risk factors, and postoperative complications were studied in children requiring LT for HB/HCC at 16 SPLIT centers. Three-year EFS was 81% for HB (n = 157) and 62% for HCC (n = 18) transplants. Of HB transplants, 6.9% were PRETEXT II and 15.3% were POST-TEXT I/II. Tumor extent did not impact survival (p = NS). Salvage (n = 13) and primary HB transplants had similar 3-year EFS (62% versus 78%, p = NS). Among HCC transplants, 3-year EFS was poorer in older patients (38% in ≥8-year-olds vs 86% <8-year-olds) and those with larger tumors (48% for those beyond versus 83% within Milan criteria, p = NS). Risk of infection (HR 1.5, 95% CI 1.1-2.2, p = .02) and renal injury (HR 2.4, 95% CI 1.7-3.3, p < .001) were higher in malignant versus nonmalignant LT. Survival is favorable for pediatric HB and HCC LT, including outcomes after salvage transplant. Unexpected numbers of LTs occurred in PRE/POST-TEXT I/II tumors. Judicious patient selection is critical to distinguish tumors that are potentially resectable; simultaneously, we must advocate for patients with unresectable malignancies to receive organs.

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.

African American Pediatric Liver Transplant Recipients Have an Increased Risk of Death After Transferring to Adult Healthcare.

OBJECTIVE: To analyze the long-term outcomes in pediatric liver transplant recipients after they have transferred to an adult provider and assess for racial disparities in health outcomes. STUDY DESIGN: This is a single-center, retrospective review of pediatric patients who underwent liver transplantation between July 1990 and August 2015 at a tertiary healthcare system with a large transplant center. Patient mortality and retransplantation were assessed after transfer to adult care. RESULTS: There were 120 patients who were transferred, of whom 19 did not meet the inclusion criteria. Of the remaining 101 patients, 64 (63%) transferred care to a nearby affiliated tertiary adult facility, 29 (29%) were followed by other healthcare systems, and 8 (8%) were lost to follow-up. Of the patients followed at our affiliated adult center, 18 of the 64 (28%) died. Of those 18 deaths, 4 (22%) occurred within the first 2 years after transfer, and 10 (55%) within 5 years of transfer. Four patients were retransplanted by an adult provider, of whom 2 eventually received a third transplant. African Americans had higher rates of death after transfer than patients of other races (44% mortality vs 16%, representing 67% of all cases of death; P = .032), with nearly 50% mortality at 20 years from time of transplantation. CONCLUSIONS: Death is common in pediatric liver transplant recipients after transfer to adult care, with African Americans having disproportionately higher mortality. This period of transition of care is a vulnerable time, and measures must be taken to ensure the safe transfer of young adults with chronic health care needs.

A two decade long study of disease progression of de novo and recurrent autoimmune hepatitis in the pediatric population.

Recurrent autoimmune hepatitis (rAIH) occurs in patients who undergo liver transplantation (LT) for AIH and de novo AIH (dAIH) is seen in patients who are transplanted for etiologies other than AIH. Whether these are distinct diseases with a similar phenotype remains understudied. The aim of this study was to identify clinical and immunologic factors affecting outcome in patients with dAIH and rAIH. A retrospective review of 387 LT patients from 1997 to 2014 was carried out, and they were followed until 2018. Patients with rAIH or dAIH were identified based on the pre-transplant diagnosis of AIH (or not) and characteristic histology. Liver biopsies were stained with H&E, B-cell marker CD20, and plasma cell marker CD138. Out of 387 patients, 31 were transplanted for AIH, and 8/31 developed rAIH. Of the remaining 356 patients, eight developed dAIH. Compared to the dAIH group, rAIH occurred in older patients, had an earlier onset in the allograft, and had higher IgG and serum ALT levels. It was most commonly seen in African American (AA) patients (87%). rAIH patients had significantly higher CD20 and CD138 positivity in liver biopsies. In addition, they had increased rejection episodes prior to the onset of recurrence, increased graft loss, and mortality. rAIH is a more aggressive disease, and has a preponderance of B cells and plasma cells in the liver tissue as compared to dAIH. The concurrent association with increased graft loss and patient mortality in rAIH warrants further investigations into B cell-targeted therapies.

Efficacy and Safety of Immunosuppression Withdrawal in Pediatric Liver Transplant Recipients: Moving Toward Personalized Management.

BACKGROUND AND AIMS: Tolerance is transplantation's holy grail, as it denotes allograft health without immunosuppression and its toxicities. Our aim was to determine, among stable long-term pediatric liver transplant recipients, the efficacy and safety of immunosuppression withdrawal to identify operational tolerance. APPROACH AND RESULTS: We conducted a multicenter, single-arm trial of immunosuppression withdrawal over 36-48 weeks. Liver tests were monitored biweekly (year 1), monthly (year 2), and bimonthly (years 3-4). For-cause biopsies were done at investigators' discretion but mandated when alanine aminotransferase or gamma glutamyltransferase exceeded 100 U/L. All subjects underwent final liver biopsy at trial end. The primary efficacy endpoint was operational tolerance, defined by strict biochemical and histological criteria 1 year after stopping immunosuppression. Among 88 subjects (median age 11 years; 39 boys; 57 deceased donor grafts), 33 (37.5%; 95% confidence interval [CI] 27.4%, 48.5%) were operationally tolerant, 16 were nontolerant by histology (met biochemical but failed histological criteria), and 39 were nontolerant by rejection. Rejection, predicted by subtle liver inflammation in trial entry biopsies, typically (n = 32) occurred at ≤32% of the trial-entry immunosuppression dose and was treated with corticosteroids (n = 32) and/or tacrolimus (n = 38) with resolution (liver tests within 1.5 times the baseline) for all but 1 subject. No death, graft loss, or chronic, severe, or refractory rejection occurred. Neither fibrosis stage nor the expression level of a rejection gene set increased over 4 years for either tolerant or nontolerant subjects. CONCLUSIONS: Immunosuppression withdrawal showed that 37.5% of selected pediatric liver-transplant recipients were operationally tolerant. Allograft histology did not deteriorate for either tolerant or nontolerant subjects. The timing and reversibility of failed withdrawal justifies future trials exploring the efficacy, safety, and potential benefits of immunosuppression minimization.

Soluble PD1 levels are increased with disease activity in paediatric onset autoimmune hepatitis and inflammatory bowel disease.

Introduction: Immune mediated liver diseases entail a broad category which are associated with increased morbidity and mortality amongst the paediatric population. Programmed Death 1 (PD1) is an inhibitory receptor mainly expressed by T cells, and when activated shed into plasma as soluble PD1(sPD1). The AIM of this study was to evaluate sPD1 levels in plasma of paediatric patients with Autoimmune Hepatitis (AIH), Primary Sclerosing Cholangitis (PSC), AIH and PSC overlap, Inflammatory Bowel Disease (IBD) alone, and concurrent PSC/IBD and AIH/IBD in order to identify a biomarker to response or predict relapse verses remission.Methods: Plasma samples were collected from 41 paediatric patients. AIH patients were further categorized into active, incomplete responders and responders, based on response to standard therapy. sPD1 levels were measured and compared between PSC, PSC/AIH, IBD alone, PSC/IBD and AIH/IBD patients and between active AIH, incomplete responders and responders. Flow cytometry was performed to further analyze CD45RA+, CD3CD4, CD8, CCR7, CXCR3, CD38 and PD1.Results: In the AIH group, those with active disease demonstrated a significantly higher sPD1 levels in comparison to responders (*p > .001). However, the incomplete responders didn't show a reduction in sPD1 in comparison to active AIH and patients with IBD alone. Interestingly, patients with PSC showed significantly lower level of sPD1 compared to active AIH (*p < .002), whereas, patients with PSC in conjunction with AIH (*p < .006) or IBD (*p < .02) demonstrated a significant increase in sPD1. In addition, we have observed increased levels of circulating CD4 and CD8 bound PD1 in active AIH but not in PSC or responders suggesting T cells activation. CD4+ PD1 double positive cells demonstrated increased expression of CXCR3. Thus, suggesting the activation of PD1 + T cells is mediating through CXCR3 in Autoimmune hepatitis.Conclusions: Our study demonstrates that sPD1 levels correlate with active disease state of AIH and IBD. sPD1 levels did not correlate with PSC. However, PSC in conjunction with AIH or IBD showed higher levels of sPD1. This suggests that T cell activation plays a critical role in active AIH and IBD but not in PSC. Soluble PDI levels could be used as a clinical biomarker to assess response in patients with AIH and for prospectively monitoring PSC patients for development of IBD or AIH.

Perceived barriers to medication adherence remain stable following solid organ transplantation.

Perceived barriers to adherence have previously been investigated in SOT to identify plausible intervention targets to improve adherence and transplant outcomes. Fifteen centers in CTOTC enrolled patients longitudinally. Patients >8 years completed Adolescent Scale(AMBS) at two visits at least 6 months apart in the first 17 months post-transplant while their guardians completed PMBS. Differences over time for pre-identified AMBS/PMBS factors were analyzed. Perceived barrier reporting impact on subsequent TAC levels was assessed. A total of 123 patients or their guardians completed PMBS or AMBS. Twenty-six were 6-11 years and 97 were ≥12. The final cohort consisted of kidney (66%), lung (19%), liver (8%), and heart (7%) recipients. Unadjusted analysis showed no statistically significant change in reported barriers from visit 1 (median 2.6 months, range 1.2-3.7 post-transplant) to visit 2 (median 12, range 8.9-16.5). Of 102 patients with TAC levels, 74 had a single level reported at both visits. The factor of "Disease frustration" was identified through the PMBS/AMBS questions about fatigue around medication and disease. Each point increase in "disease frustration" at visit 1 on the AMBS/PMBS doubled the odds of a lower-than-threshold TAC level at visit 2. No clear change in overall level of perceived barriers to medication adherence in the first year post-transplant was seen in pediatric SOT. However, disease frustration early post-transplant was associated with a single subtherapeutic TAC levels at 12 months. A brief screening measure may allow for early self-identification of risk.

Influence of Fat on Differential Receptor Interacting Serine/Threonine Protein Kinase 1 Activity Leading to Apoptotic Cell Death in Murine Liver Ischemia Reperfusion Injury Through Caspase 8.

Current understanding is that receptor interacting serine/threonine protein kinase 1 (RIPK1) can lead to two distinct forms of cell death: RIPK3-mediated necroptosis or caspase 8 (Casp8)-mediated apoptosis. Here, we report that RIPK1 signaling is indispensable for protection from hepatocellular injury in a steatotic liver undergoing ischemia reperfusion injury (IRI) but not in the lean liver. In lean liver IRI, RIPK1-mediated cell death is operational, leading to protection in RIP1 kinase-dead knock-in (RIPK1K45A) mice and necrostatin-1s (Nec1s)-treated lean wild-type (WT) mice. However, when fed a high-fat diet (HFD), RIPK1K45A-treated and Nec1s-treated WT mice undergoing IRI demonstrate exacerbated hepatocellular injury along with decreased RIPK1 ubiquitylation. Furthermore, we demonstrate that HFD-fed RIPK3-/-/Casp8-/- mice show protection from IRI, but HFD-fed RIPK3-/-/Casp8-/+ mice do not. We also show that blockade of RIPK1 leads to increased Casp8 activity and decreases mitochondrial viability. Conclusion: Although more studies are required, we provide important proof of concept for RIPK1 inhibition leading to distinctive outcomes in lean and steatotic liver undergoing IRI. Considering the rising incidence of nonalcoholic fatty liver disease (NAFLD) in the general population, it will be imperative to address this critical difference when treating patients with RIPK1 inhibitors. This study also presents a new target for drug therapy to prevent hepatocellular injury in NAFLD.

20- to 25-year patient and graft survival following a single pediatric liver transplant-Analysis of the United Network of Organ Sharing database: Where to go from here.

To understand factors contributing to liver graft loss and patient death, we queried a national database designed to follow pediatric patients transplanted between 1987 and 1995 till adulthood. A comparison was made to a cohort transplanted between 2000 and 2014. The 5-, 10-, 15-, 20-, and 25-year patient survival and graft survival were 95.5%, 93.7%, 89.1%, 80.8%, and 73.1%, and 92.5%, 86.7%, 77.6%, 68.7%, and 62.2%, respectively. The twenty-year patient/graft survival was significantly worse in those transplanted between 5 and 17 years of age compared to those transplanted at <5 years of age (P < 0.001). For the modern era cohort, the 3-year patient survival was significantly lower in children transplanted at 16-17 years of age compared to those transplanted at <5 and 11-15 years of age (P ≤ 0.02). The 3-year graft survival was similarly lower in children transplanted at 16-17 years of age compared to those transplanted at <5, 5-10, and 11-15 years of age (P ≤ 0.001). Infection as a cause of death occurred either early or >15 years post-transplant. Chronic rejection remained the leading cause of graft loss in both cohorts and the commonest indication for retransplantation 20-25 years following primary transplant. Further research is required to identify modifiable factors contributing to development of chronic rejection.

Racial disparities in presentation and outcomes of paediatric autoimmune hepatitis.

BACKGROUND & AIMS: Most studies on autoimmune hepatitis (AIH) in children are in predominantly Caucasian cohorts. Paediatric AIH in African Americans (AA) is understudied, with a dearth of clinical predictors of outcome, often leading to serious complications and even mortality. The aim of the study was to define disease presentation, progression, response to therapy and outcomes in paediatric AIH in a well-defined, large, single centre, demographically diverse population. METHODS: We conducted a review of patients with AIH who were followed at this tertiary liver transplant centre. Clinical and laboratory covariates were assessed with regard to disease presentation, progression and outcomes in AA vs Non-AA children. RESULTS: African Americans patients constituted 42% of this cohort. At 1-year follow-up, AA children were receiving significantly higher doses of steroids compared to non-AA. More AA presented with end-stage liver disease (ESLD) with high immunoglobulin G and GGT:platelet ratio. After adjusting for other risk factor variables like gender, age at presentation and ESLD, AA children were at 4.5 times higher risk for significant outcome liver transplant/death within the first 12 months of presentation. Post-transplant, recurrent AIH was seen in 50% of AA vs 8% in non-AA. CONCLUSIONS: African American patients with AIH are more likely to present with ESLD and have an increased early risk for transplantation with high likelihood of disease recurrence post-transplantation. Studies are needed to delineate factors such as inherent biology, genetics and access to care. Early referral and tailored immunosuppressive regimens are required for AA patients with AIH.

Evidence of Chronic Allograft Injury in Liver Biopsies From Long-term Pediatric Recipients of Liver Transplants.

BACKGROUND & AIMS: A substantial proportion of pediatric liver transplant recipients develop subclinical chronic allograft injury. We studied whether there are distinct patterns of injury based on histopathologic features and identified associated immunologic profiles. METHODS: We conducted a cross-sectional study of 157 stable, long-term pediatric recipients of transplanted livers (70 boys; > 6 years old at time of transplantation; mean, 8.9 ± 3.46 years after liver transplantation) who underwent liver biopsy analysis from August 13, 2012, through May 1, 2014. Participants had received livers from a living or deceased donor and had consistently normal results from liver tests. Liver biopsy specimens were scored by a central pathologist; an unsupervised hierarchical cluster analysis of histologic features was used to sort biopsy samples into 3 clusters. We conducted transcriptional and cytometric analyses of liver tissue samples and performed a systems biology analysis that incorporated clinical, serologic, histologic, and transcriptional data. RESULTS: The mean level of alanine aminotransferase in participants was 27.6 ± 14.57 U/L, and the mean level of γ-glutamyl transferase was 17.4 ± 7.93 U/L. Cluster 1 was characterized by interface activity (n = 34), cluster 2 was characterized by periportal or perivenular fibrosis without interface activity (n = 45), and cluster 3 had neither feature (n = 78). We identified a module of genes whose expression correlated with levels of alanine aminotransferase, class II donor-specific antibody, portal inflammation, interface activity, perivenular inflammation, portal and perivenular fibrosis, and cluster assignment. The module was enriched in genes that regulate T-cell-mediated rejection (TCMR) of liver and other transplanted organs. Functional pathway analysis showed overrepresentation of TCMR gene sets for cluster 1 but not clusters 2 or 3. CONCLUSION: In an analysis of biopsies from an apparently homogeneous group of stable, long-term pediatric liver transplant recipients with consistently normal liver test results, we found evidence of chronic graft injury (inflammation and/or fibrosis). Biopsy samples with interface activity had a gene expression pattern associated with TCMR.

Frailty in Children with Liver Disease: A Prospective Multicenter Study.

OBJECTIVE: To assess frailty, a measure of physiologic declines in multiple organ systems, in children with chronic liver disease using a novel pediatric frailty tool. STUDY DESIGN: We performed a prospective cross-sectional multicenter study at 17 liver transplantation (LT) centers. 71 children (5-17 years of age), 36 with compensated chronic liver disease (CCLD) and 35 with end-stage liver disease (ESLD) and listed for LT, were assessed for frailty using validated pediatric tools to assess the 5 classic Fried Frailty Criteria-slowness, weakness, exhaustion, diminished physical activity, and shrinkage. Test scores were translated to age- and sex-dependent z scores, generating a maximum frailty score of 10. RESULTS: The median frailty score of the cohort was 4 (IQR 3, 5). Subjects with ESLD had significantly higher frailty scores (median 5; IQR 4, 7) than subjects with CCLD (median 3; IQR 2, 4); (P < .0001). Area under the curve receiver operating characteristic for frailty scores to discriminate between ESLD and CCLD was 0.83 (95% CI 0.73, 0.93). Forty-six percent of children with ESLD were frail and there was no correlation between pediatric frailty scores and physician's global assessments (r = -0.24, 95% CI -0.53, 0.10). CONCLUSIONS: A novel frailty tool assessed additional dimensions of health, not captured by standard laboratory measures and identified the sickest individuals among a cohort of children with chronic liver disease. This tool may have applicability to other children with chronic disease.

Clinical Efficacy of Percutaneous Transhepatic Portal Vein Angioplasty for Late-onset Portal Vein Stenosis in Pediatric Liver Transplant Patients.

BACKGROUND: Stenosis of the portal vein (PV) is a rare complication after liver transplantation (LT) in pediatric patients, and it adversely affects outcomes. We reviewed the safety and efficacy of percutaneous transhepatic balloon angioplasty (PTBA) as a treatment for post-LT late-onset PV stenosis (PVS). METHODS: Three hundred eighteen patients between the ages of 0 and 21 years received an LT from 2001 to 2016 at this tertiary center. Twenty-one children were evaluated for PVS using percutaneous portal venography. RESULTS: Of the 21, 19 patients (7 female, 12 male) with a median age of 12 years (7-15 years) were diagnosed with PVS and received PTBA. Two patients were excluded: one did not have PVS, and one received shunt surgery. Median time between LT and PTBA was 83 months (interquartile range, 49-138). For patients in whom pressure could be accurately measured (n = 9), mean PV pressure gradient was 6.3 mm Hg (SD, 5.0) preprocedure and 0.9 mm Hg (SD, 1.2) postprocedure. Mean percentage improvement in gradient across the stenotic region was 86.2% (SD, 15.9%; P < 0.01). At 12-month postprocedure, there was a mean improvement (pre-PTBA vs post-PTBA means) in bilirubin by 28.2% (0.6 mg/dL vs 0.4 mg/dL, P = 0.07), aspartate aminotransferase by 31.2% (116.3 IU/L vs 28.1 IU/L, P = 0.04), alanine aminotransferase by 40.7% (140.3 IU/L vs 28.6 IU/L, P = 0.07), γ-glutamyltransferase by 29.0% (337.2 IU/L vs 38.0 IU/L, P = 0.06) and platelets by 62.1% (128.3 vs 191.1 × 10/L, P = 0.03). The PV patency was successfully maintained in 18 of 19 patients for a median of 16 months (interquartile range, 5-35). One patient received a successful repeat procedure for restenosis at 6 weeks. CONCLUSION: Angioplasty for PVS after pediatric LT is a safe and effective treatment with good patency and improved clinical outcomes. Longer follow-up studies are required.