Vicky L. Ng

NOTCH2 mutations in Alagille syndrome

Background Alagille syndrome (ALGS) is a dominant, multisystem disorder caused by mutations in the Jagged1 (JAG1) ligand in 94% of patients, and in the NOTCH2 receptor in <1%. There are only two NOTCH2 families reported to date. This study hypothesised that additional NOTCH2 mutations would be present in patients with clinical features of ALGS without a JAG1 mutation. Methods The study screened a cohort of JAG1-negative individuals with clinical features suggestive or diagnostic of ALGS for NOTCH2 mutations. Results Eight individuals with novel NOTCH2 mutations (six missense, one splicing, and one non-sense mutation) were identified. Three of these patients met classic criteria for ALGS and five patients only had a subset of features. The mutations were distributed across the extracellular (N=5) and intracellular domains (N=3) of the protein. Functional analysis of four missense, one nonsense, and one splicing mutation demonstrated decreased Notch signalling of these proteins. Subjects with NOTCH2 mutations demonstrated highly variable expressivity of the affected systems, as with JAG1 individuals. Liver involvement was universal in NOTCH2 probands and they had a similar prevalence of ophthalmologic and renal anomalies to JAG1 patients. There was a trend towards less cardiac involvement in the NOTCH2 group (60% vs 100% in JAG1). NOTCH2 (+) probands exhibited a significantly decreased penetrance of vertebral abnormalities (10%) and facial features (20%) when compared to the JAG1 (+) cohort. Conclusions This work confirms the importance of NOTCH2 as a second disease gene in ALGS and expands the repertoire of the NOTCH2 related disease phenotype.

Variability in tacrolimus blood levels increases the risk of late rejection and graft loss after solid organ transplantation in older children

Pollock‐BarZiv SM, Finkelstein Y, Manlhiot C, Dipchand AI, Hebert D, Ng VL, Solomon M, McCrindle BW, Grant D. Variability in tacrolimus blood levels increases the risk of late rejection and graft loss after solid organ transplantation in older children.
Pediatr Transplantation 2010: 14:968–975.

Intravenous N-acetylcysteine in pediatric patients with nonacetaminophen acute liver failure: A placebo-controlled clinical trial

N‐acetylcysteine (NAC) was found to improve transplantation‐free survival in only those adults with nonacetaminophen (non‐APAP) acute liver failure (ALF) and grade 1‐2 hepatic encephalopathy (HE). Because non‐APAP ALF differs significantly between children and adults, the Pediatric Acute Liver Failure (PALF) Study Group evaluated NAC in non‐APAP PALF. Children from birth through age 17 years with non‐APAP ALF enrolled in the PALF registry were eligible to enter an adaptively allocated, doubly masked, placebo‐controlled trial using a continuous intravenous infusion of NAC (150 mg/kg/day in 5% dextrose in water [D5W]) or placebo (D5W) for up to 7 days. The primary outcome was 1‐year survival. Secondary outcomes included liver transplantation‐free survival, liver transplantation (LTx), length of intensive care unit (ICU) and hospital stays, organ system failure, and maximum HE score. A total of 184 participants were enrolled in the trial with 92 in each arm. The 1‐year survival did not differ significantly (P = 0.19) between the NAC (73%) and placebo (82%) treatment groups. The 1‐year LTx‐free survival was significantly lower (P = 0.03) in those who received NAC (35%) than those who received placebo (53%), particularly, but not significantly so, among those less than 2 years old with HE grade 0‐1 (NAC 25%; placebo 60%; P = 0.0493). There were no significant differences between treatment arms for hospital or ICU length of stay, organ systems failing, or highest recorded grade of HE. Conclusion: NAC did not improve 1‐year survival in non‐APAP PALF. One‐year LTx‐free survival was significantly lower with NAC, particularly among those <2 years old. These results do not support broad use of NAC in non‐APAP PALF and emphasizes the importance of conducting controlled pediatric drug trials, regardless of results in adults. (HEPATOLOGY 2013)

Detection of acetaminophen protein adducts in children with acute liver failure of indeterminate cause

OBJECTIVE. Acetaminophen cysteine protein adducts are a widely recognized correlate of acetaminophen-mediated hepatic injury in laboratory animals. The objective of this study was to use a new assay for the detection of acetaminophen cysteine protein adducts in children with acute liver failure to determine the role of acetaminophen toxicity in acute liver failure of unknown cause. METHODS. Serum samples from children with acute liver failure were measured for acetaminophen cysteine protein adducts using high-performance liquid chromatography with electrochemical detection. For comparison, samples from children with well-characterized acetaminophen toxicity and children with known other causes of acute liver failure also were measured for acetaminophen cysteine protein adducts. The analytical laboratory was blinded to patient diagnoses. RESULTS. Acetaminophen cysteine protein adduct was detected in 90% of samples from children with acute liver failure that was attributed to acetaminophen toxicity, 12.5% of samples from children with acute liver failure of indeterminate cause, and 9.6% of samples from children with acute liver failure that was attributed to other causes. Adduct-positive patients from the indeterminate cause subgroup had higher levels of serum aspartate aminotransferase and alanine aminotransferase and lower levels of bilirubin. Adduct-positive patients also had lower rates of transplantation and higher rates of spontaneous remission. CONCLUSIONS. A small but significant percentage of children with acute liver failure of indeterminate cause tested positive for acetaminophen cysteine protein adducts, strongly suggesting acetaminophen toxicity as the cause of acute liver failure. An assay for the detection of acetaminophen cysteine protein adducts can aid the diagnosis of acetaminophen-related liver injury in children.

Sirolimus for pediatric liver transplant recipients with post‐transplant lymphoproliferative disease and hepatoblastoma

Abstract:  Sirolimus is a promising immune suppressive agent, with the potential to reduce calcineurin inhibitor associated nephrotoxicity, halt progression of chronic rejection and prevent tumor proliferation. The aim of this study was to review the experience using sirolimus in pediatric liver transplant recipients at a single center. Database and medical charts of all pediatric liver transplant recipients receiving sirolimus at the Hospital for Sick Children in Toronto were reviewed. Eight patients received sirolimus between October, 2000 and September, 2002. Indications for using sirolimus were post‐transplant lymphoproliferative disease (PTLD) (n = 6) and hepatoblastoma (n = 2). Two patients with PTLD concurrently had renal impairment and chronic rejection. Sirolimus dosages ranged between 1.5 and 5 mg once daily. Median duration of follow‐up was 17 months. Persistently elevated liver transaminase levels in the two children with chronic rejection decreased during sirolimus therapy. Recurrence of PTLD occurred in one patient. Two patients were diagnosed with acute cellular rejection after transition to maintenance sirolimus monotherapy. Resolution of adverse effects including mouth sores (n = 3), leg swelling (n =  2) and hyperlipidemia (n = 3) occurred either spontaneously or with dose reduction. Sirolimus was discontinued in four patients because of persisting bone marrow suppression, interstitial pneumonitis, life‐threatening sepsis and refractory diarrhea. Children with PTLD or hepatoblastoma may benefit from immune suppression with sirolimus after liver transplantation. Further multi‐center, prospective, randomized controlled trials will be instrumental to further the knowledge of long‐term efficacy, safety and tolerability of sirolimus for selected children following liver transplantation.

Health status ten years after pediatric liver transplantation--looking beyond the graft.

Background. Little is known about long-term health after pediatric orthotopic liver transplantation (OLT). This study aimed to characterize the health status of recipients 10 years after OLT, with an emphasis on transplant-related morbidity and quality of life. Methods. We performed a retrospective database review of 32 children who underwent OLT before October 1992 at one center and were alive after 10 years. Outcome measures were assessed 10 years after OLT. Cantril’s self-anchoring scale was used for global quality of life assessment. Results. Synthetic liver function at 10 years was preserved in all patients. The annual rate of episodes of acute rejection dropped markedly after the first year (1.4 at year 1 to 0.19 rejections/patient/year at year 10). Histologically confirmed chronic rejection developed in eight (25%) patients. At 10 years, long-term complications included mild to severe chronic renal failure (77%), mild chronic anemia (59%), and hypertension (25%). Significant growth retardation (z-score < −2), hyperlipidemia, and diabetes were uncommon. Infection requiring hospitalization occurred in 81% of the patients, with varicella zoster virus as the most common pathogen. Epstein-Barr virus-related malignancies affected 22% of patients. Ten-year survivors perceived quality of life as very good. Self-reporting of drug nonadherence by seven (22%) adolescents may have contributed to development of late onset rejection in this subgroup. Conclusions. Children who are 10-year survivors of OLT have excellent graft function and, despite chronic extrahepatic morbidities, a self-reported high quality of life.

Extrahepatic Anomalies in Infants With Biliary Atresia: Results of a Large Prospective North American Multicenter Study

The etiology of biliary atresia (BA) is unknown. Given that patterns of anomalies might provide etiopathogenetic clues, we used data from the North American Childhood Liver Disease Research and Education Network to analyze patterns of anomalies in infants with BA. In all, 289 infants who were enrolled in the prospective database prior to surgery at any of 15 participating centers were evaluated. Group 1 was nonsyndromic, isolated BA (without major malformations) (n = 242, 84%), Group 2 was BA and at least one malformation considered major as defined by the National Birth Defects Prevention Study but without laterality defects (n = 17, 6%). Group 3 was syndromic, with laterality defects (n = 30, 10%). In the population as a whole, anomalies (either major or minor) were most prevalent in the cardiovascular (16%) and gastrointestinal (14%) systems. Group 3 patients accounted for the majority of subjects with cardiac, gastrointestinal, and splenic anomalies. Group 2 subjects also frequently displayed cardiovascular (71%) and gastrointestinal (24%) anomalies; interestingly, this group had genitourinary anomalies more frequently (47%) compared to Group 3 subjects (10%). Conclusion: This study identified a group of BA (Group 2) that differed from the classical syndromic and nonsyndromic groups and that was defined by multiple malformations without laterality defects. Careful phenotyping of the patterns of anomalies may be critical to the interpretation of both genetic and environmental risk factors associated with BA, allowing new insight into pathogenesis and/or outcome. (Hepatology 2013;58:1724–1731)

Evaluation of the pediatric patient for liver transplantation: 2014 practice guideline by the american association for the study of liver diseases, american society of transplantation and the north american society for pediatric gastroenterology, hepatology and nutrition

Current American Association for the Study of Liver Diseases (AASLD) liver transplant evaluation guidelines include both adult and pediatric patients. While pediatric liver transplants account for 7.8% of all liver transplants in the United States, sufficient differences between pediatric and adult patients seeking liver transplantation (LT) now require independent, yet complementary documents. This document will focus on pediatric issues at each level of the evaluation process. Disease categories suitable for referral to a pediatric LT program are similar to adults: acute liver failure, autoimmune, cholestasis, metabolic or genetic, oncologic, vascular, and infectious. However, specific etiologies and outcomes differ widely from adult patients, justifying independent pediatric guidelines. Data supporting our recommendations are based on a Medline search of the English language literature from 1997 to the present. Intended for use by physicians, these recommendations suggest preferred approaches to the diagnostic, therapeutic, and preventive aspects of care. They are intended to be flexible, in contrast to standards of care, which are inflexible policies to be followed in every case. Specific recommendations are based on relevant published information. To more fully characterize the available evidence supporting the recommendations, the AASLD Practice Guidelines Committee has adopted the classification used by the Grading of Recommendation Assessment, Development, and Evaluation (GRADE) workgroup with minor modifications (Table 1). The classifications and recommendations are based on three categories: the source of evidence in levels I through III; the Abbreviations: ALF, acute liver failure; GRADE, Grading of Recommendation Assessment, Development, and Evaluation; HB, hepatoblastoma; HCC, hepatocellular carcinoma; HPE, hepatoportoenterostomy; LT, liver transplantation; OTPN, Organ Procurement and Transplantation Network; PFIC, progressive familial intrahepatic cholestasis; TIPS, transjugular intrahepatic portosystemic shunt. From the Department of Pediatrics, University of Pittsburgh School of Medicine; Division of Pediatric Gastroenterology, Hepatology and Nutrition, Children’s Hospital of Pittsburgh of UPMC, Pittsburgh, PA; Department of Pediatrics, University of Toronto; Division of Pediatric Gastroenterology, Hepatology and Nutrition, SickKids Transplant and Regenerative Medicine Center, Hospital for Sick Children, Toronto, Canada; Department of Pediatrics, Division of Pediatric Gastroenterology, Hepatology, and Nutrition, Emory University School of Medicine; Children’s Healthcare of Atlanta, Atlanta, GA; Department of Pediatrics, Division of Pediatric Gastroenterology and Hepatology, Yale School of Medicine, New Haven, CT; Department of Paediatrics, University of Melbourne; Department of Gastroenterology, Royal Children’s Hospital, Melbourne, Australia; Department of Surgery, Section of Transplantation and Immunology, Yale School of Medicine, New Haven, CT; Department of Surgery, University of Pittsburgh School of Medicine; Division of Pediatric Transplantation, Hillman Center for Pediatric Transplantation, Children’s Hospital of Pittsburgh of UPMC, Pittsburgh, PA. Financial support to develop this practice guideline was provided by the American Association for the Study of Liver Diseases. All AASLD Practice Guidelines are updated annually. If you are viewing a Practice Guideline that is more than 12 months old, please visit www.aasld.org for an update in the material. Received April 22, 2014; accepted April 22, 2014. Address reprint requests to: Robert H. Squires, M.D., Professor of Pediatrics, University of Pittsburgh, Children’s Hospital of Pittsburgh of UPMC, 4401 Penn Ave., Pittsburgh, PA 15224. E-mail: squiresr@upmc.edu Copyright VC 2014 by the American Association for the Study of Liver Diseases. View this article online at wileyonlinelibrary.com. DOI 10.1002/hep.27191 Potential conflict of interest: Dr. Romero received grants from Bristol-Myers Squibb.

Liver retransplantation in children: a SPLIT database analysis of outcome and predictive factors for survival.

To examine outcomes and identify prognostic factors affecting survival after pediatric liver transplantation, data from 246 children who underwent a second liver transplantation (rLT) between 1996 and 2004 were analyzed from the SPLIT registry, a multi‐center database currently comprised of 45 North American pediatric liver transplant programs. The main causes for loss of primary graft necessitating rLT were primary nonfunction, vascular complications, chronic rejection and biliary complications. Three‐month, 1‐ and 2‐year patient survival rates were inferior after rLT (74%, 67% and 65%) compared with primary LT (92%, 88% and 85%, respectively). Multivariate analysis of pretransplant variables revealed donor age less than 1 year, use of a technical variant allograft and INR at time of rLT as independent predictive factors for survival after rLT. Survival of patients who underwent early rLT (ErLT, <30 days after LT) was poorer than those who received rLT >30 days after LT (late rLT, LrLT): 3‐month, 1‐ and 2‐year patient survival rates 66%, 59%, and 56% versus 80%, 74% and 61%, respectively, log‐rank p = 0.0141. Liver retransplantation in children is associated with decreased survival compared with primary LT, particularly, in the clinical settings of those patients requiring ErLT.

Quality of Life After Pediatric Solid Organ Transplantation

Long-term survival after pediatric solid organ transplantation is now the rule rather than the exception for increasing numbers of children with end-stage organ diseases. While transplantation restores organ function it does not necessarily return one to a normal life. Therefore, it is prudent to focus on assessment of not only traditional biologic outcomes but also the quality life for these children and their families. This article gives a brief overview of current definitions, conceptualizations, approaches to measurement of, and unique considerations in the evaluation of quality of life in children who have undergone solid organ transplant. Current understanding of quality of life in children who have undergone solid organ transplantation is reviewed, followed by limitations of current knowledge. Clinical implications are discussed and future research directions suggested.