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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

Loss of L-selectin-guided CD8+ , but not CD4+ , cells protects against ischemia reperfusion injury in a steatotic liver.

Steatotic liver responds with increased hepatocellular injury when exposed to an ischemic-reperfusion insult. Increasing evidence supports the role of immune cells as key mediators of this injury in a normal (lean) state, but data about their role in a steatotic liver are practically nonexistent. The objective of the current study was to delineate the contribution of specific phenotypes of T cells and adhesion molecules in exacerbated cell death in steatotic liver injury. RNA sequencing was performed on isolated steatotic primary hepatocytes, and T-cell markers were assessed in hepatic lymphocytes after ischemia reperfusion injury (IRI) in high-fat diet (HFD)-fed mice. Cluster of differentiation 8 knockout (CD8-/- ) and CD4-/- mice along with CD8 and L-selectin antibody-treated mice were fed an HFD, and hepatocellular injury was assessed by histology, propidium iodide injection, and alanine aminotransferase after IRI. RNA sequencing demonstrated a strikingly differential gene profile in steatotic hepatocytes versus lean hepatocytes. After injury, the HFD liver showed increased necrosis, infiltrating CD8+ cells, alanine aminotransferase, and proinflammatory cytokines. Hepatic lymphocytes demonstrated increased CD8+ /CD62L+ (L-selectin) cells in HFD-fed mice after IRI. CD8-/- mice and CD8-depleted C57BL/6 mice demonstrated significant protection from injury, which was not seen in CD4-/- mice. L-selectin blockade also demonstrated significant hepatoprotection from IRI. L-selectin ligand MECA-79 was increased in HFD-fed mice undergoing IRI. CONCLUSION: Blockade of CD8 and L-selectin, but not CD4, ameliorated hepatocellular injury, confirming that CD8+ cells are critical drivers of injury in a steatotic liver; this represents a therapeutic target in steatotic liver injury, underlining the importance of development of therapies specific to a steatotic liver. (Hepatology 2017;66:1258-1274).

Contrast-Based Real-Time Assessment of Microcirculatory Changes in a Fatty Liver After Ischemia Reperfusion Injury.

OBJECTIVES: A fatty liver is known to have impairment of microcirculation, which is worsened after ischemia reperfusion injury (IRI). This makes most fatty grafts unsuitable for transplantation, and in the absence of real time assessment of microcirculation this selection has been at best, random. The aim of this study was to demonstrate the utility of a contrast enhanced ultrasound model in quantitative assessment of the microcirculation of a fatty liver. METHODS: We subjected fatty mice to IRI, and blood flow dynamics were assessed before and after the injury. RESULTS: There was a significant increase in the resistive and pulsatility index of the extrahepatic artery and a significant decrease in velocity of the portal vein. There was also a quantifiable decrease in the intrahepatic blood volume, blood flow, time to peak flow, and perfusion index of mice with fatty liver, suggesting that a fatty liver develops hemodynamic abnormalities after IRI, leading to increased hepatocellular injury. CONCLUSIONS: Hemodynamic abnormalities in liver can be reliably quantified using a contrast, enhanced Doppler ultrasound, which is an inexpensive technique with multiple clinical applications. It can be used to assess the quality of the fatty liver donor graft before organ retrieval; for determining live donor candidacy, for making post-IRI recovery prognosis, and for assessing the effectiveness of therapeutic interventions.

Perceived barriers to medication adherence in pediatric and adolescent solid organ transplantation.

Comparisons of perceived barriers to adherence in pediatric and adolescent SOT have not been systematically conducted despite association between medication non-adherence and poor outcome. Fifteen centers in CTOT-C enrolled patients in a cross-sectional study. Subjects' guardians completed the PMBS and subjects over eight completed the Adolescent Scale (AMBS). Association of three identified PMBS factors and subject age was assessed. Secondary analyses assessed associations between PMBS, AMBS, and patient demographics. Three hundred sixty-eight subjects or their guardians completed PMBS or AMBS. A total of 107 subjects were 6-11 yr; 261 were ≥12. Unadjusted and propensity-adjusted analyses indicated higher perceived barriers in guardians of adolescents as compared to guardians of pre-adolescents medication scheduling and frustration domains regardless of organ (p < 0.05). PMBS and AMBS comparisons revealed that guardians reported fewer ingestion issues than patients (p = 0.018), and differences appeared more pronounced within younger responders for scheduling (p = 0.025) and frustration (p = 0.019). Screening revealed guardians of older patients report increased perceived barriers to adherence independent of socioeconomic status. Guardians of adolescents reported fewer perceived barriers to ingestion/side effects than patients themselves, particularly in pre-adolescents (8-11 yr). Brief screening measures to assess perceived barriers should be further studied in adherence improvement programs.

Mitigation of autophagy ameliorates hepatocellular damage following ischemia-reperfusion injury in murine steatotic liver.

Ischemia-reperfusion injury (IRI) is a common clinical consequence of hepatic surgery, cardiogenic shock, and liver transplantation. A steatotic liver is particularly vulnerable to IRI, responding with extensive hepatocellular injury. Autophagy, a lysosomal pathway balancing cell survival and cell death, is engaged in IRI, although its role in IRI of a steatotic liver is unclear. The role of autophagy was investigated in high-fat diet (HFD)-fed mice exposed to IRI in vivo and in steatotic hepatocytes exposed to hypoxic IRI (HIRI) in vitro. Two inhibitors of autophagy, 3-methyladenine and bafilomycin A1, protected the steatotic hepatocytes from HIRI. Exendin 4 (Ex4), a glucagon-like peptide 1 analog, also led to suppression of autophagy, as evidenced by decreased autophagy-associated proteins [microtubule-associated protein 1A/1B-light chain 3 (LC3) II, p62, high-mobility group protein B1, beclin-1, and autophagy-related protein 7], reduced hepatocellular damage, and improved mitochondrial structure and function in HFD-fed mice exposed to IRI. Decreased autophagy was further demonstrated by reversal of a punctate pattern of LC3 and decreased autophagic flux after IRI in HFD-fed mice. Under the same conditions, the effects of Ex4 were reversed by the competitive antagonist exendin 9-39. The present study suggests that, in IRI of hepatic steatosis, treatment of hepatocytes with Ex4 mitigates autophagy, ameliorates hepatocellular injury, and preserves mitochondrial integrity. These data suggest that therapies targeting autophagy, by Ex4 treatment in particular, may ameliorate the effects of IRI in highly prevalent steatotic liver.

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.

The glucagon-like peptide-1 receptor agonist Exendin 4 has a protective role in ischemic injury of lean and steatotic liver by inhibiting cell death and stimulating lipolysis.

Nonalcoholic fatty liver disease is an increasingly prevalent spectrum of conditions characterized by excess fat deposition within hepatocytes. Affected hepatocytes are known to be highly susceptible to ischemic insults, responding to injury with increased cell death, and commensurate liver dysfunction. Numerous clinical circumstances lead to hepatic ischemia. Mechanistically, specific means of reducing hepatic vulnerability to ischemia are of increasing clinical importance. In this study, we demonstrate that the glucagon-like peptide-1 receptor agonist Exendin 4 (Ex4) protects hepatocytes from ischemia reperfusion injury by mitigating necrosis and apoptosis. Importantly, this effect is more pronounced in steatotic livers, with significantly reducing cell death and facilitating the initiation of lipolysis. Ex4 treatment leads to increased lipid droplet fission, and phosphorylation of perilipin and hormone sensitive lipase - all hallmarks of lipolysis. Importantly, the protective effects of Ex4 are seen after a short course of perioperative treatment, potentially making this clinically relevant. Thus, we conclude that Ex4 has a role in protecting lean and fatty livers from ischemic injury. The rapidity of the effect and the clinical availability of Ex4 make this an attractive new therapeutic approach for treating fatty livers at the time of an ischemic insult.

Magnetic resonance imaging identifies unsuspected liver abnormalities in patients after the Fontan procedure.

OBJECTIVE: To determine whether abdominal magnetic resonance imaging (MRI) detects hepatic abnormalities before clinical or biochemical perturbations in patients after the Fontan procedure. STUDY DESIGN: Thirty-nine children and adolescents who underwent the Fontan procedure and were referred to a pediatric hepatologist by cardiology services between 2011 and 2012 were reviewed retrospectively. Physical examination findings, routine laboratory tests of liver function, evaluation for chronic liver disease, and abdominal MRI findings were recorded. MRI findings were evaluated relative to time elapsed since surgery by 2 radiologists (blinded). RESULTS: Assessment for coexisting chronic liver disease was negative in all patients. All patients had a normal serum albumin level and International Normalized Ratio. Twenty-six of the 39 patients (67%) underwent abdominal MRI, 4 had MRI-incompatible hardware, and 9 did not undergo MRI because of insurance denial. All MRI scans demonstrated morphologic liver changes with varying degrees of reticular contrast enhancement compatible with fibrosis and congestion. Reticular contrast enhancement was often nonuniform, and 9 patients (35%) had multifocal arterially enhancing lesions. CONCLUSION: MRI can identify hepatic abnormalities in patients after Fontan surgery that go undetected by standard clinical and laboratory assessments. These abnormalities are not uniformly distributed throughout the liver, and thus assessment by liver biopsy analysis is subject to sampling error.

The SPLIT research agenda 2013.

This review focuses on active clinical research in pediatric liver transplantation with special emphasis on areas that could benefit from studies utilizing the SPLIT infrastructure and data repository. Ideas were solicited by members of the SPLIT Research Committee and sections were drafted by members of the committee with expertise in those given areas. This review is intended to highlight priorities for clinical research that could successfully be conducted through the SPLIT collaborative and would have significant impact in pediatric liver transplantation.