Yumirle P. Turmelle

Risk factors for rejection and infection in pediatric liver transplantation.

Rejection and infection are important adverse events after pediatric liver transplantation, not previously subject to concurrent risk analysis. Of 2291 children (<18 years), rejection occurred at least once in 46%, serious bacterial/fungal or viral infections in 52%. Infection caused more deaths than rejection (5.5% vs. 0.6% of patients, p < 0.001). Early rejection (<6 month) did not contribute to mortality or graft failure. Recurrent/chronic rejection was a risk in graft failure, but led to retransplant in only 1.6% of first grafts. Multivariate predictors of bacterial/fungal infection included recipient age (highest in infants), race, donor organ variants, bilirubin, anhepatic time, cyclosporin (vs. tacrolimus) and era of transplant (before 2002 vs. after 2002); serious viral infection predictors included donor organ variants, rejection, Epstein‐Barr Virus (EBV) naivety and era; for rejection, predictors included age (lowest in infants), primary diagnosis, donor‐recipient blood type mismatch, the use of cyclosporin (vs. tacrolimus), no induction and era. In pediatric liver transplantation, infection risk far exceeds that of rejection, which causes limited harm to the patient or graft, particularly in infants. Aggressive infection control, attention to modifiable factors such as pretransplant nutrition and donor organ options and rigorous age‐specific review of the risk/benefit of choice and intensity of immunosuppressive regimes is warranted.

p21 is Required for Dextrose-Mediated Inhibition of Mouse Liver Regeneration

The inhibitory effect of dextrose supplementation on liver regeneration was first described more than 4 decades ago. Nevertheless, the molecular mechanisms responsible for this observation have not been elucidated. We investigated these mechanisms using the partial hepatectomy model in mice given standard or 10% dextrose (D10)‐supplemented drinking water. The results showed that D10‐treated mice exhibited significantly reduced hepatic regeneration compared with controls, as assessed by hepatocellular bromodeoxyuridine (BrdU) incorporation and mitotic frequency. D10 supplementation did not suppress activation of hepatocyte growth factor (HGF), induction of transforming growth factor alpha (TGF‐α) expression, or tumor necrosis factor alpha–interleukin‐6 cytokine signaling, p42/44 extracellular signal‐regulated kinase (ERK) activation, immediate early gene expression, or expression of CCAAT/enhancer binding protein beta (C/EBPβ), but did augment expression of the mito‐inhibitory factors C/EBPα, p21Waf1/Cip1, and p27Kip1. In addition, forkhead box M1 (FoxM1) expression, which is required for normal liver regeneration, was suppressed by D10 treatment. Finally, D10 did not suppress either FoxM1 expression or hepatocellular proliferation in p21 null mice subjected to partial hepatectomy, establishing the functional significance of these events in mediating the effects of D10 on liver regeneration. Conclusion: These data show that the inhibitory effect of dextrose supplementation on liver regeneration is associated with increased expression of C/EBPα, p21, and p27, and decreased expression of FoxM1, and that D10‐mediated inhibition of liver regeneration is abrogated in p21‐deficient animals. Our observations are consistent with a model in which hepatic sufficiency is defined by homeostasis between the energy‐generating capacity of the liver and the energy demands of the body mass, with liver regeneration initiated when the functional liver mass is no longer sufficient to meet such demand. (HEPATOLOGY 2009.)

Use of Corticosteroids After Hepatoportoenterostomy for Bile Drainage in Infants With Biliary Atresia: The START Randomized Clinical Trial

IMPORTANCE Biliary atresia is the most common cause of end-stage liver disease in children. Controversy exists as to whether use of steroids after hepatoportoenterostomy improves clinical outcome. OBJECTIVE To determine whether the addition of high-dose corticosteroids after hepatoportoenterostomy is superior to surgery alone in improving biliary drainage and survival with the native liver. DESIGN, SETTING, AND PATIENTS The multicenter, double-blind Steroids in Biliary Atresia Randomized Trial (START) was conducted in 140 infants (mean age, 2.3 months) between September 2005 and February 2011 in the United States; follow-up ended in January 2013. INTERVENTIONS Participants were randomized to receive intravenous methylprednisolone (4 mg/kg/d for 2 weeks) and oral prednisolone (2 mg/kg/d for 2 weeks) followed by a tapering protocol for 9 weeks (n = 70) or placebo (n = 70) initiated within 72 hours of hepatoportoenterostomy. MAIN OUTCOMES AND MEASURES The primary end point (powered to detect a 25% absolute treatment difference) was the percentage of participants with a serum total bilirubin level of less than 1.5 mg/dL with his/her native liver at 6 months posthepatoportoenterostomy. Secondary outcomes included survival with native liver at 24 months of age and serious adverse events. RESULTS The proportion of participants with improved bile drainage was not statistically significantly improved by steroids at 6 months posthepatoportoenterostomy (58.6% [41/70] of steroids group vs 48.6% [34/70] of placebo group; adjusted relative risk, 1.14 [95% CI, 0.83 to 1.57]; P = .43). The adjusted absolute risk difference was 8.7% (95% CI, -10.4% to 27.7%). Transplant-free survival was 58.7% in the steroids group vs 59.4% in the placebo group (adjusted hazard ratio, 1.0 [95% CI, 0.6 to 1.8]; P = .99) at 24 months of age. The percentage of participants with serious adverse events was 81.4% [57/70] of the steroids group and 80.0% [56/70] of the placebo group (P > .99); however, participants receiving steroids had an earlier time of onset of their first serious adverse event by 30 days posthepatoportoenterostomy (37.2% [95% CI, 26.9% to 50.0%] of steroids group vs 19.0% [95% CI, 11.5% to 30.4%] of placebo group; P = .008). CONCLUSIONS AND RELEVANCE Among infants with biliary atresia who have undergone hepatoportoenterostomy, high-dose steroid therapy following surgery did not result in statistically significant treatment differences in bile drainage at 6 months, although a small clinical benefit could not be excluded. Steroid treatment was associated with earlier onset of serious adverse events in children with biliary atresia. TRIAL REGISTRATION clinicaltrials.gov Identifier: NCT00294684.

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)

Evidence for non-traditional activation of complement factor C3 during murine liver regeneration.

UNLABELLED Complement signaling has been implicated as important for normal hepatic regeneration. However, the specific mechanism by which complement is activated during liver regeneration remains undefined. To address this question, we investigated the hepatic regenerative response to partial hepatectomy in wildtype mice, C3-, C4-, and factor B-null mice, and C4-null mice treated with a factor B neutralizing antibody (mAb 1379). The results showed that following partial hepatectomy, C3-null mice exhibit reduced hepatic regeneration compared to wildtype mice as assessed by quantification of hepatic cyclin D1 expression and hepatocellular DNA synthesis and mitosis. In contrast, C4-null mice and factor B-null mice demonstrated normal liver regeneration. Moreover, animals in which all of the traditional upstream C3 activation pathways were disrupted, i.e. C4-null mice treated with mAb 1379, exhibited normal C3 activation and hepatocellular proliferation following partial hepatectomy. In order to define candidate non-traditional mechanisms of C3 activation during liver regeneration, plasmin and thrombin were investigated for their abilities to activate C3 in mouse plasma in vitro. The results showed that both proteases are capable of initiating C3 activation, and that plasmin can do so independent of the classical and alternative pathways. CONCLUSIONS These results show that C3 is required for a normal hepatic regenerative response, but that disruption of the classical- or lectin-dependent pathways (C4-dependent), the alternative pathway (factor B-dependent), or all of these pathways does not impair the hepatic regenerative response, and indicate that non-traditional mechanisms by which C3 is activated during hepatic regeneration must exist. In vitro analysis raises the possibility that plasmin may contribute to non-traditional complement activation during liver regeneration in vivo.

Efficacy of Fat-Soluble Vitamin Supplementation in Infants With Biliary Atresia

OBJECTIVE: Cholestasis predisposes to fat-soluble vitamin (FSV) deficiencies. A liquid multiple FSV preparation made with tocopheryl polyethylene glycol-1000 succinate (TPGS) is frequently used in infants with biliary atresia (BA) because of ease of administration and presumed efficacy. In this prospective multicenter study, we assessed the prevalence of FSV deficiency in infants with BA who received this FSV/TPGS preparation. METHODS: Infants received FSV/TPGS coadministered with additional vitamin K as routine clinical care in a randomized double-blinded, placebo-controlled trial of corticosteroid therapy after hepatoportoenterostomy (HPE) for BA (identifier NCT 00294684). Levels of FSV, retinol binding protein, total serum lipids, and total bilirubin (TB) were measured 1, 3, and 6 months after HPE. RESULTS: Ninety-two infants with BA were enrolled in this study. Biochemical evidence of FSV insufficiency was common at all time points for vitamin A (29%–36% of patients), vitamin D (21%–37%), vitamin K (10%–22%), and vitamin E (16%–18%). Vitamin levels were inversely correlated with serum TB levels. Biochemical FSV insufficiency was much more common (15%–100% for the different vitamins) in infants whose TB was ≥2 mg/dL. At 3 and 6 months post HPE, only 3 of 24 and 0 of 23 infants, respectively, with TB >2 mg/dL were sufficient in all FSV. CONCLUSIONS: Biochemical FSV insufficiency is commonly observed in infants with BA and persistent cholestasis despite administration of a TPGS containing liquid multiple FSV preparation. Individual vitamin supplementation and careful monitoring are warranted in infants with BA, especially those with TB >2 mg/dL.

Portal hypertension in children and young adults with biliary atresia

Objective: Biliary atresia (BA) frequently results in portal hypertension (PHT), complications of which lead to significant morbidity and mortality. The Childhood Liver Disease Research and Education Network was used to perform a cross-sectional multicentered analysis of PHT in children with BA. Methods: Subjects with BA receiving medical management at a Childhood Liver Disease Research and Education Network site were enrolled. A priori, clinically evident PHT was defined as “definite” when there was either history of a complication of PHT or clinical findings consistent with PHT (both splenomegaly and thrombocytopenia). PHT was denoted as “possible” if one of the findings was present in the absence of a complication, whereas PHT was “absent” if none of the criteria were met. Results: A total of 163 subjects were enrolled between May 2006 and December 2009. At baseline, definite PHT was present in 49%, possible in 17%, and absent in 34% of subjects. Demographics, growth, and anthropometrics were similar amongst the 3 PHT categories. Alanine aminotransferase, &ggr;-glutamyl transpeptidase, and sodium levels were similar, whereas there were significant differences in aspartate aminotransferase (AST), AST/alanine aminotransferase, albumin, total bilirubin, prothrombin time, white blood cell count, platelet count, and AST/platelet count between definite and absent PHT. Thirty-four percent of those with definite PHT had either prothrombin time >15 seconds or albumin <3 g/dL. Conclusions: Clinically definable PHT is present in two-thirds of North American long-term BA survivors with their native livers. The presence of PHT is associated with measures of hepatic injury and dysfunction, although in this selected cohort, the degree of hepatic dysfunction is relatively mild and growth is preserved.

Human polyomaviruses in children undergoing transplantation, United States, 2008-2010

Immunocompromised patients are at risk for disease caused by infection by some polyomaviruses. To define the prevalence of polyomaviruses in children undergoing transplantation, we collected samples from a longitudinal cohort and tested for the 9 known human polyomaviruses. All were detected; several were present in previously unreported specimen types.

Prolonged Neonatal Jaundice and the Diagnosis of Biliary Atresia: A Single-Center Analysis of Trends in Age at Diagnosis and Outcomes

Age at diagnosis is a modifiable risk factor in outcomes after hepatoportoenterostomy in biliary atresia; however, distinguishing biliary atresia from other more common causes of prolonged neonatal jaundice can be difficult. To focus attention on diagnosis of biliary atresia, we analyzed secular trends in the age at diagnosis, and other factors that might influence outcome. We performed a retrospective analysis of 55 consecutive infants with biliary atresia presenting to a single academic pediatric center over 15-year period from 1990 to 2004. The median age at diagnosis was 60 days (range: 21–152). In recent era (2000–2004), the median age was 69.0 days, compared with 48.5 days (1990–1994) and 59.5 days (1995–1999), respectively. Consistent with previous studies, the median age at diagnosis of those with poor outcomes (death or liver transplant) exceeded those with good outcomes after the hepatoportoenterostomy (72 vs 52 days, P < .001). The lack of improvement, or a concerning trends toward an increase in the age at diagnosis of biliary atresia, is perhaps attributable to neonatal follow-up practices. Efforts to make an earlier diagnose of this important condition deserve wider application and study.

Biliary strictures in pediatric liver transplant recipients – Early diagnosis and treatment results in excellent graft outcomes

Anderson CD, Turmelle YP, Darcy M, Shepherd RW, Weymann A, Nadler M, Guelker S, Chapman WC, Lowell JA. Biliary strictures in pediatric liver transplant recipients – Early diagnosis and treatment results in excellent graft outcomes.
Pediatr Transplantation 2010: 14:358–363.