Portal vein complications and outcomes following pediatric liver transplantation: Data from the Society of Pediatric Liver Transplantation.

Children who undergo liver transplantation are at risk for portal vein complications (PVCs) including thrombosis (PVT) and stenosis (PVS). Using multicenter data from the Society of Pediatric Liver Transplantation, we analyzed the prevalence, timing, and risk factors for PVC following a first liver transplantation, and assessed the potential impact of PVC on patient outcomes. Our cohort included 4278 patients, of whom 327 (7.6%) developed PVC. Multivariate analysis discovered several factors independently associated with PVC: younger recipient age, lower weight at time of transplantation, diagnosis of biliary atresia (BA), receiving a technical variant graft (TVG), warm ischemia time over 3 h, PVT in the recipient's pretransplantation native liver, and concurrent hepatic artery thrombosis (all p < 0.05). Subgroup analysis of those with BA found higher prevalence in patients transplanted at less than 2 years of age and those with TVGs. There was no difference in PVC prevalence among patients with BA with vs. without prior Kasai portoenterostomy. Most PVT (77.7%) presented within 90 days after transplantation. Patients with PVC had a higher risk of graft failure (23.9% vs. 8.3%; adjusted hazard ratio [HR], 3.08; p < 0.001) and a higher risk of death (16.4% vs. 8.9%; adjusted HR, 1.96; p = 0.01). Recurrence after retransplantation was similar to the overall prevalence in the cohort (8.2%). Our results recognize the common occurrence of PVC following pediatric liver transplantation, describe independently associated risk factors, and determine that patients with PVC have worse outcomes. Further studies are needed to improve PVC prevention, detection, and management strategies.

North American Biliary Stricture Management Strategies in Children After Liver Transplantation: A Multicenter Analysis From the Society of Pediatric Liver Transplantation (SPLIT) Registry.

Biliary strictures affect 4%-12% of pediatric liver transplantations. Biliary strictures can contribute to graft loss if left untreated; however, there remains no consensus on the best course of treatment. Study objectives included analyses of outcomes associated with biliary stricture management strategies via percutaneous transhepatic cholangiography (PTC), endoscopic retrograde cholangiopancreatography (ERCP), or surgery. We identified pediatric liver transplantation recipients (2011-2016) with biliary strictures from the Society of Pediatric Liver Transplantation (SPLIT) registry and retrieved imaging, procedural, and operative reports from individual centers. Subanalyses were performed to specifically evaluate PTC and ERCP for "optimal biliary outcome" (OBO), defined as graft survival with stricture resolution and without recurrence or surgery. A total of 113 children with a median follow-up of 3.9 years had strictures diagnosed 100 days (interquartile range, 30-290) after liver transplantation; 81% were isolated anastomotic strictures. Stricture resolution was achieved in 92% within 101 days, more frequently with isolated anastomotic strictures (96%). 20% of strictures recurred, more commonly in association with hepatic artery thrombosis (32%). Patient and graft survival at 1 and 3 years were 99% and 98% and 94% and 92%, respectively. In a subgroup analysis of 79 patients with extrahepatic strictures managed by PTC/ERCP, 59% achieved OBO following a median of 4 PTC, and 75% following a median of 3 ERCP (P < 0.001). Among patients with OBO, those with ERCP had longer time intervals between successive procedures (41, 47, 54, 62, 71 days) than for PTC (27, 31, 36, 41, 48 days; P < 0.001). Allograft salvage was successful across all interventions. Stricture resolution was achieved in 92%, with 20% risk of recurrence. Resolution without recurrence was highest in patients with isolated anastomotic strictures and without hepatic artery thrombosis.

Ischemia reperfusion injury induces pyroptosis and mediates injury in steatotic liver thorough Caspase 1 activation.

A steatotic liver is increasingly vulnerable to ischemia reperfusion injury (IRI), and the underlying mechanisms are incompletely defined. Caspases are endo-proteases, which provide critical regulatory connections between cell death and inflammation. Caspase 1 is driven by inflammasomes which are key signaling platforms, that detect sterile stressors (DAMPs), releasing the highly pro-inflammatory cytokine interleukin IL-8 and IL-1ß. To delineate the involvement of Caspase 1 and 11 in hepatocellular injury in steatotic liver undergoing IRI. Male C57BL6/Wild Type and Caspase 1Null, Caspase 11-/- and Caspase 1-/-/11-/- mice were fed a high fat diet (HFD) for 12 weeks. These mice were subjected to 40 min of ischemia followed by 2-24 h of reperfusion. Hepatocellular injury was assessed by histopathologic injury scoring, serum ALT and propidium iodide (PI) uptake, mRNA levels of Caspase 1, IL-1ß by RT PCR, Caspase 1 activity assay and Caspase 1. Specific Caspase 1, inhibitor experiments were carried out. All groups gained similar body weight after a 12-week HFD. Cleaved Caspase 1 protein levels, Caspase 1 mRNA levels were significantly higher in steatotic liver undergoing IRI. Executor of pyroptosis cleaved GSDMD levels were higher in HFD fed mouse compared to lean. In addition, genetic deletion of Caspase 1, Casp1Null mouse expressing Caspase-11 and Caspase 1/11 double knock out demonstrated significant reduction in serum ALT (p < 0.01), Injury Score, (p < 0.0002) but not in Caspase 11 alone. Caspase 1 is the driver of hepatocellular injury in a steatotic liver undergoing IRI, inhibition of which leads to hepatoprotection, thus providing a therapeutic target for clinical use.

TRANSITION of Pediatric Liver Transplant Patients to Adult Care: a Review.

PURPOSE OF REVIEW: Many pediatric liver transplant patients are surviving to adulthood, and providers have come to recognize the importance of effectively transitioning these patients to an adult hepatologist. The review aims to analyze the most recent literature regarding patient outcomes after transition, barriers to successful transition, recommendations from clinicians and medical societies regarding transition programs, and to provide personal insights from our experience in transitioning liver transplant recipients. RECENT FINDINGS: While results were variable between studies, many recent reports show significant morbidity and mortality in patients following transition to adult care. Medical non-adherence is frequently seen in adolescents and young adults both prior to and after transition, and is consistently associated with higher rates of rejection, graft loss, and death. In general, transplant programs with a formal transition process had better patient outcomes though recent findings are mostly-single center and direct comparison between programs is difficult. Societal recommendations for how to create a transition program contain a number of common themes that we have categorized for easier understanding. Successful transition is vital to the continued health of pediatric liver transplant patients. While an effective transition program includes a number of key components, it should be individualized to best function within a given transplant center. Here, we have reviewed a number of recent single-center retrospective studies on transition, but multi-site retrospective or prospective data is lacking, and is a fertile area for future research.

Glucagon-like peptide-1 receptor is present on human hepatocytes and has a direct role in decreasing hepatic steatosis in vitro by modulating elements of the insulin signaling pathway.

UNLABELLED: Glucagon-like peptide 1 (GLP-1) is a naturally occurring peptide secreted by the L cells of the small intestine. GLP-1 functions as an incretin and stimulates glucose-mediated insulin production by pancreatic beta cells. In this study, we demonstrate that exendin-4/GLP-1 has a cognate receptor on human hepatocytes and that exendin-4 has a direct effect on the reduction of hepatic steatosis in the absence of insulin. Both glucagon-like peptide 1 receptor (GLP/R) messenger RNA and protein were detected on primary human hepatocytes, and receptor was internalized in the presence of GLP-1. Exendin-4 increased the phosphorylation of 3-phosphoinositide-dependent kinase-1 (PDK-1), AKT, and protein kinase C zeta (PKC-zeta) in HepG2 and Huh7 cells. Small interfering RNA against GLP-1R abolished the effects on PDK-1 and PKC-zeta. Treatment with exendin-4 quantitatively reduced triglyceride stores compared with control-treated cells. CONCLUSION: This is the first report that the G protein-coupled receptor GLP-1R is present on human hepatocytes. Furthermore, it appears that exendin-4 has the same beneficial effects in vitro as those seen in our previously published in vivo study in ob/ob mice, directly reducing hepatocyte steatosis. Future use for human nonalcoholic fatty liver disease, either in combination with dietary manipulation or other pharmacotherapy, may be a significant advance in treatment of this common form of liver disease.

Pediatric liver transplantation for acute liver failure at a single center: a 10-yr experience.

Children transplanted for ALF urgently require an optimal graft and have lower post-transplant survival compared with children transplanted for chronic liver disease. Over 10 yr, 33 consecutive children transplanted for ALF were followed. Demographics, encephalopathy, intubation, dialysis, laboratory values, graft type ABOI, XL (GRWR > 5%), DDSLT, LDLT and WLT were evaluated. Complications and survival were determined. ALF accounted for 33/201 (16.4%) of transplants during this period. Twelve of 33 received ABOI, five XL grafts, 18 DDSLT, and three LDLT. Waiting time pretransplant was 2.1 days. One- and three-yr patient survival in the ALF group was 93.4% and 88.9%, and graft survivals were 86.4% and 77.7%. Median follow-up was 1452 days. ABOI one- and three yr patient and graft survival in the ALF was 91.6% and 78.6%. No difference in graft or patient survival was noted in the ALF and chronic liver disease group or the ABOI and the ABO compatible group. A combination of ABO incompatible donor livers, XL grafts, DDSLT, LDLT and WLT led to a short wait time and subsequent graft and patient survival comparable to patients with non-acute disease.

Growing Up: Not an Easy Transition-Perspectives of Patients and Parents regarding Transfer from a Pediatric Liver Transplant Center to Adult Care.

The transition from pediatric to adult care is a critical time when children with chronic illness sustain high morbidity and mortality. Transition services need to be focused on the adolescents' needs, which may differ from those perceived by healthcare providers. In this study, a survey of 31 patients with chronic liver disease and/or liver transplant who were "transferred" to adult services within the last 3 years was conducted. Patients were asked about their current health status and their perceptions of the overall transfer process. The mean age at transfer was 19.81 (18-21) years. Almost half the patients (47%) were not seen at the adult facility until 2-6 months after leaving the Children's hospital and 20% were not seen until 6-12 months. About 20% had their first contact with adult services through an emergency room visit. About 19% reported being out of medication during transition. Of the transplanted patients, 19% were being evaluated for a retransplant. The majority (82%) felt that an increased emphasis on promoting independence and "letting go" both by parents and by pediatric care providers was critical in their transition to independence and adult care services. This study provides thought-provoking insights, which are critical in designing the ideal transition program for children with chronic diseases.

Pediatric hepatopulmonary syndrome is seen with polysplenia/interrupted inferior vena cava and without cirrhosis.

Hepatopulmonary syndrome (HPS) is a triad of liver dysfunction, hypoxemia, and intrapulmonary vascular dilatation. We describe the prevalence and clinical features of HPS at a pediatric liver transplant center. Patients referred to Children's Healthcare of Atlanta/Emory University transplant program from February 1999 to May 2005 were reviewed. Oxygen saturation in room air was screened by percutaneous pulse oximetry. HPS cases were compared with similar age non-HPS recipients (n = 38) to determine differences in clinical characteristics, Pediatric End-Stage Liver Disease (PELD) scores, and posttransplantation survival. Of 211 patients referred and 114 patients transplanted, 7 met criteria for HPS (3.3% and 6.1%, respectively). Patients with HPS had lower PELD score (-0.4 +/- 5.9 vs. 11 +/- 11; P = 0.01) and total bilirubin (1.7 +/- 1.1 vs. 11.2 +/- 10.1; P = 0.02) at the time of transplantation. Four of 7 patients with HPS had polysplenia/interrupted inferior vena cava (PS/IVC) compared with 0 of 38 age-matched controls (P = 0.0002). Three patients with HPS did not have cirrhosis; 2 of these 3 had PS/IVC. All HPS cases normalized room air oxygen saturation by 6 months, and survival after transplantation in HPS cases was 100%. Marked hepatic synthetic or biochemical dysfunction may not be present, and cirrhosis is not a requirement for the development of HPS in children. HPS in children is frequently associated with PS/IVC. Histologic evidence of abnormal intrahepatic portal vein flow and the demonstration of portosystemic communications at any level should be sought in children presenting with unexplained intrapulmonary vascular dilatation. Liver transplantation for HPS in childhood may be appropriate even in the absence of cirrhosis.

Exendin-4, a glucagon-like protein-1 (GLP-1) receptor agonist, reverses hepatic steatosis in ob/ob mice.

Nonalcoholic fatty liver disease (NAFLD) represents a burgeoning problem in hepatology, and is associated with insulin resistance. Exendin-4 is a peptide agonist of the glucagon-like peptide (GLP) receptor that promotes insulin secretion. The aim of this study was to determine whether administration of Exendin-4 would reverse hepatic steatosis in ob/ob mice. Ob/ob mice, or their lean littermates, were treated with Exendin-4 [10 microg/kg or 20 microg/kg] for 60 days. Serum was collected for measurement of insulin, adiponectin, fasting glucose, lipids, and aminotransferase concentrations. Liver tissue was procured for histological examination, real-time RT-PCR analysis and assay for oxidative stress. Rat hepatocytes were isolated and treated with GLP-1. Ob/ob mice sustained a reduction in the net weight gained during Exendin-4 treatment. Serum glucose and hepatic steatosis was significantly reduced in Exendin-4 treated ob/ob mice. Exendin-4 improved insulin sensitivity in ob/ob mice, as calculated by the homeostasis model assessment. The measurement of thiobarbituric reactive substances as a marker of oxidative stress was significantly reduced in ob/ob-treated mice with Exendin-4. Finally, GLP-1-treated hepatocytes resulted in a significant increase in cAMP production as well as reduction in mRNA expression of stearoyl-CoA desaturase 1 and genes associated with fatty acid synthesis; the converse was true for genes associated with fatty acid oxidation. In conclusion, Exendin-4 appears to effectively reverse hepatic steatosis in ob/ob mice by improving insulin sensitivity. Our data suggest that GLP-1 proteins in liver have a novel direct effect on hepatocyte fat metabolism.