Taurocholate Induces Biliary Differentiation of Liver Progenitor Cells Causing Hepatic Stellate Cell Chemotaxis in the Ductular Reaction: Role in Pediatric Cystic Fibrosis Liver Disease.

Cystic fibrosis liver disease (CFLD) in children causes progressive fibrosis leading to biliary cirrhosis; however, its cause(s) and early pathogenesis are unclear. We hypothesized that a bile acid-induced ductular reaction (DR) drives fibrogenesis. The DR was evaluated by cytokeratin-7 immunohistochemistry in liver biopsies, staged for fibrosis, from 60 children with CFLD, and it demonstrated that the DR was significantly correlated with hepatic fibrosis stage and biliary taurocholate levels. To examine the mechanisms involved in DR induction, liver progenitor cells (LPCs) were treated with taurocholate, and key events in DR evolution were assessed: LPC proliferation, LPC biliary differentiation, and hepatic stellate cell (HSC) chemotaxis. Taurocholate induced a time-dependent increase in LPC proliferation and expression of genes associated with cholangiocyte differentiation (cytokeratin 19, connexin 43, integrin ß4, and γ-glutamyltranspeptidase), whereas the hepatocyte specification marker HNF4α was suppressed. Functional cholangiocyte differentiation was demonstrated via increased acetylated α-tubulin and SOX9 proteins, the number of primary cilia+ LPCs, and increased active γ-glutamyltranspeptidase enzyme secretion. Taurocholate induced LPCs to release MCP-1, MIP1α, and RANTES into conditioned medium causing HSC chemotaxis, which was inhibited by anti-MIP1α. Immunofluorescence confirmed chemokine expression localized to CK7+ DR and LPCs in CFLD liver biopsies. This study suggests that taurocholate is involved in initiating functional LPC biliary differentiation and the development of the DR, with subsequent induction of chemokines that drive HSC recruitment in CFLD.

Bile salt export pump-reactive antibodies form a polyclonal, multi-inhibitory response in antibody-induced bile salt export pump deficiency.

UNLABELLED: Progressive familial intrahepatic cholestasis type 2 (PFIC-2) is caused by mutations in ABCB11, encoding the bile salt export pump (BSEP). In 2009, we described a child with PFIC-2 who developed PFIC-like symptoms after orthotopic liver transplantation (OLT). BSEP-reactive antibodies were demonstrated to account for disease recurrence. Here, we characterize the nature of this antibody response in 7 more patients with antibody-induced BSEP deficiency (AIBD). Gene sequencing and immunostaining of native liver biopsies indicated absent or strongly reduced BSEP expression in all 7 PFIC-2 patients who suffered from phenotypic disease recurrence post-OLT. Immunofluorescence, western blotting analysis, and transepithelial transport assays demonstrated immunoglobulin (Ig) G-class BSEP-reactive antibodies in these patients. In all cases, the N-terminal half of BSEP was recognized, with reaction against its first extracellular loop (ECL1) in six sera. In five, antibodies reactive against the C-terminal half also were found. Only the sera recognizing ECL1 showed inhibition of transepithelial taurocholate transport. In a vesicle-based functional assay, transport inhibition by anti-BSEP antibodies binding from the cytosolic side was functionally proven as well. Within 2 hours of perfusion with antibodies purified from 1 patient, rat liver showed canalicular IgG staining that was absent after perfusion with control IgG. CONCLUSIONS: PFIC-2 patients carrying severe BSEP mutations are at risk of developing BSEP antibodies post-OLT. The antibody response is polyclonal, targeting both extra- and intracellular BSEP domains. ECL1, a unique domain of BSEP, likely is a critical target involved in transport inhibition as demonstrated in several patients with AIBD manifest as cholestasis.

A 10-Year united network for organ sharing review of mortality and risk factors in young children awaiting liver transplantation.

Young children < 2 years of age with chronic end-stage liver disease (YC2) are a uniquely vulnerable group listed for liver transplantation, characterized by a predominance of biliary atresia (BA). To investigate wait-list mortality, associated risk factors, and outcomes of YC2, we evaluated United Network for Organ Sharing registry data from April 2003 to March 2013 for YC2 listed for deceased donor transplant (BA = 994; other chronic liver disease [CLD] = 221). Overall, wait-list mortality among YC2 was 12.4% and posttransplant mortality was 8%, accounting for an overall postlisting mortality of 19.6%. YC2 demonstrated 12.2%, 18.7%, and 20.6% wait-list mortality by 90, 180, and 270 days, respectively. YC2 with CLD demonstrated significantly higher wait-list mortality compared with BA among YC2 (23.9% versus 9.8%; P < 0.05). Multivariate analyses revealed that listing Pediatric End-Stage Liver Disease [PELD] > 21 (hazard ratio [HR], 3.2; 95% confidence interval [CI], 1.6-6.5), lack of exception (HR, 5.8; 95% CI, 2.8-11.8), listing height < 60.6 cm (HR, 2.1; 95% CI, 1.4-3.1), listing weight > 10 kg (HR, 3.8; 95% CI, 1.5-9.2), and initial creatinine > 0.5 (HR, 6.8; 95% CI, 3.4-13.5) were independent risk factors for YC2 wait-list mortality (P < 0.005 for all). Adjusting for all variables, the risk of death among CLD patients was 2 (95% CI, 1.3-3.1) times greater than patients with BA + surgery (presumed Kasai). Furthermore, the risk of death in BA without surgery was 1.9 (95% CI, 1­3.4) times greater than BA with presumed Kasai. Our data highlight unacceptably high wait-list and early post-liver transplant mortality in YC2 not predicted by PELD and suggest key risk factors deserving of further study in this age group. Liver Transplantation 22 1584-1592 2016 AASLD.

Aspartate aminotransferase to platelet ratio and fibrosis-4 as biomarkers in biopsy-validated pediatric cystic fibrosis liver disease.

UNLABELLED: Up to 10% of cystic fibrosis (CF) children develop cirrhosis by the first decade. We evaluated the utility of two simple biomarkers, aspartate aminotransferase to platelet ratio index (APRI) and FIB-4, in predicting degree of fibrosis in pediatric CF liver disease (CFLD) validated by liver biopsy. In this retrospective, cross-sectional study, 67 children with CFLD had dual-pass liver biopsies and 104 age- and sex-matched CF children without liver disease (CFnoLD) had serum to calculate APRI and FIB-4 collected at enrollment. CFLD was defined as having two of the following: (1) hepatomegaly±splenomegaly; (2)>6 months elevation of ALT (>1.5× upper limit of normal ULN); or (3) abnormal liver ultrasound findings. Biopsies were staged according to Metavir classification by two blinded pathologists. Receiver operating characteristic (ROC) analysis and continuation ratio logistic regression were performed to assess the predictability of these biomarkers to distinguish CFLD from CFnoLD and determine fibrosis stage-specific cut-off values. The AUC for APRI was better than FIB-4 (0.75 vs. 0.60; P=0.005) for predicting CFLD and severe CFLD (F3-F4) (0.81). An APRI score>0.264 demonstrated a sensitivity (95% confidence interval [CI]) of 73.1% (60.9, 83.2) and specificity of 70.2% (60.4, 78.8) in predicting CFLD. A 50% increase in APRI was associated with a 2.4-fold (95% CI: 1.7, 3.3) increased odds of having CFLD. APRI demonstrated full agreement with histology staging 37% of the time, but was within one stage 73% of the time. Only FIB-4 predicted portal hypertension at diagnosis (area under the receiver operator characteristic curve [AUC 0.91; P<0.001). CONCLUSION: This is the first liver biopsy-validated study of APRI and FIB-4 in pediatric CFLD. APRI appears superior to FIB-4 in differentiating CFLD versus CFnoLD. APRI also exhibited a high AUC in predicting severe liver fibrosis with specific cutoffs for lower stages.

Newborn Direct or Conjugated Bilirubin Measurements As a Potential Screen for Biliary Atresia.

OBJECTIVES: Although screening for biliary atresia (BA) is associated with improved outcomes, no screening program currently exists in the United States. In this study, we explore the possibility of a screening strategy based on newborn direct or conjugated bilirubin (DB or CB) measurements. Our objective is to estimate testing's sensitivity and specificity for BA. METHODS: Two groups were examined retrospectively. For sensitivity calculations, a BA group consisting of infants born between January 2011 and December 2014, diagnosed with BA, and cared for at a pediatric gastroenterology referral center was examined. For specificity calculations, a non-BA group that comprised of infants born between June 2009 and August 2011 in a hospital with a policy of checking newborn bilirubin concentrations was studied. RESULTS: All 35 infants with newborn DB or CB measurements in the BA group had elevated concentrations, translating to a sensitivity of 100% (95% CI 87.7-100). In the non-BA group, 8936 of 9102 infants had DB concentrations within the laboratory's reference interval, translating to a specificity of 98.2% (95% CI 97.9-98.4). Three methods-calculating direct:total bilirubin ratios, using 99% reference intervals, and repeat testing-changed specificity to different degrees. CONCLUSIONS: Newborn DB or CB measurements may have a high sensitivity and specificity for BA. Specificity can be further improved by using 99% reference intervals and/or repeat testing. Our findings can serve as the foundation for larger prospective studies, to determine whether newborn DB or CB measurements can be an effective screening strategy for BA.

Circulating microRNAs as noninvasive diagnostic biomarkers of liver disease in children with cystic fibrosis.

OBJECTIVES: Cystic fibrosis liver disease (CFLD), resulting from progressive hepatobiliary fibrosis, causes significant morbidity and mortality in up to 20% of children with cystic fibrosis (CF). Both pathogenesis and early detection of CFLD are elusive. Current diagnostic procedures to detect early CFLD and stage fibrosis severity are inadequate. Recent studies highlight a role for microRNAs (miRNAs) in the pathogenesis of many diseases and have suggested that serum miRNAs could be used as diagnostic biomarkers. METHODS: We profiled circulating serum miRNA levels in patients with CFLD (n = 52), patients with CF without liver disease (CFnoLD, n = 30), and non-CF pediatric controls (n = 20). Extracted RNA was subjected to polymerase chain reaction (PCR) array of 84 miRNAs detectable in human serum. Seven candidate miRNAs identified were validated by reverse transcription-quantitative polymerase chain reaction (RT-qPCR), normalizing data to geNorm-determined stable reference genes, miR-19b and miR-93. RESULTS: miR-122 was significantly elevated in patients with CFLD versus patients with CFnoLD and controls (P < 0.0001). miR-25 (P = 0.0011) and miR-21 (P = 0.0133) were elevated in patients with CFnoLD versus patients with CFLD and controls. CFLD was discriminated by both miR-122 (area under the curve [AUC] 0.71, P = 0.002) and miR-25 (AUC 0.65, P = 0.026). Logistic regression combining 3 miRNAs (-122, -25, -21) was greatly predictive of detecting CFLD (AUC 0.78, P < 0.0001). A combination of 6 miRNAs (-122, -21, -25, -210, -148a, -19a) distinguished F0 from F3-F4 fibrosis (AUC 0.73, P = 0.04), and miR-210 combined with miR-22 distinguished F0 fibrosis from any fibrosis, that is, F1-F4 (AUC 0.72, P = 0.02). CONCLUSIONS: These data provide the first evidence of changes to circulating miRNA levels in CF, suggesting that serum-based miRNA analysis may complement and extend current CFLD screening strategies with potential to predict early hepatic fibrosis.

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.

Health related quality of life in patients with biliary atresia surviving with their native liver.

OBJECTIVES: To quantify health related quality of life (HRQOL) of patients with biliary atresia with their native livers and compare them with healthy children and patients with biliary atresia post-liver transplant (LT) and to examine the relationship between HRQOL and medical variables. STUDY DESIGN: A cross-sectional HRQOL study of patients with biliary atresia with their native livers (ages 2-25 years) was conducted and compared with healthy and post-LT biliary atresia samples using Pediatric Quality of Life Inventory 4.0 child self and parent proxy reports, a validated measure of physical/psychosocial functioning. RESULTS: 221 patients with biliary atresia with native livers (54% female, 67% white) were studied. Patient self and parent proxy reports showed significantly poorer HRQOL than healthy children across all domains (P < .001), particularly in emotional and psychosocial functioning. Child self and parent proxy HRQOL scores from patients with biliary atresia with their native livers and post-LT biliary atresia were similar across all domains (P = not significant). Child self and parent proxy reports showed moderate agreement across all scales, except social functioning (poor to fair agreement). On multivariate regression analysis, black race and elevated total bilirubin were associated with lower Total and Psychosocial HRQOL summary scores. CONCLUSIONS: HRQOL in patients with biliary atresia with their native livers is significantly poorer than healthy children and similar to children with post-LT biliary atresia. These findings identify significant opportunities to optimize the overall health of patients with biliary atresia.

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.

Importance of hepatic fibrosis in cystic fibrosis and the predictive value of liver biopsy.

UNLABELLED: Cystic fibrosis liver disease (CFLD), which results from progressive hepatobiliary fibrosis, is an important cause of morbidity and mortality, but it is difficult to identify before portal hypertension (PHT) ensues. Clinical signs, serum alanine aminotransferase (ALT) levels, and ultrasound (US) are widely applied, but their value in predicting the presence of cirrhosis, the development of PHT, or adverse outcomes is undetermined. The potential gold standard, liver biopsy, is not standard practice and, notwithstanding sampling error considerations, has not been systematically evaluated. Forty patients with cystic fibrosis (median age = 10.6 years) with abnormal clinical, biochemical, and US findings were subjected to dual-pass percutaneous liver biopsy. Clinical outcomes were recorded over 12 years of follow-up (median = 9.5 years for survivors). Logistic regression and receiver operating characteristic analyses were applied to predict hepatic fibrosis (which was assessed by fibrosis staging and quantitative immunohistochemistry) and the occurrence of PHT. PHT occurred in 17 of 40 patients (42%), including 6 of 7 (17%) who died during follow-up. Clinical examination, serum ALT levels, and US findings failed to predict either the presence of liver fibrosis or the development of PHT. Fibrosis staging on liver biopsy, where the accuracy was improved by dual passes (P = 0.002, nonconcordance = 38%), predicted the development of PHT (P < 0.001), which occurred more frequently and at a younger age in those with severe fibrosis. CONCLUSION: Clinical modalities currently employed to evaluate suspected CFLD help to identify a cohort of children at risk for liver disease and adverse outcomes but do not predict an individual's risk of liver fibrosis or PHT development. Liver fibrosis on biopsy predicts the development of clinically significant liver disease. Dual passes help to address sampling concerns. Liver biopsy has a relevant role in the management of patients with suspected CFLD and deserves more widespread application.

Transcriptional basis for hepatic fibrosis in cystic fibrosis-associated liver disease.

OBJECTIVES: Liver disease contributes to significant morbidity and mortality in cystic fibrosis (CF). Although all patients with CF express the defective CF transmembrane conductance regulator in cholangiocytes, many develop asymptomatic fibrosing liver disease. Only some develop cirrhosis, with pathogenesis remaining enigmatic. Available noninvasive diagnostic tools do not identify patients at risk before development of advanced fibrosis. We conducted a pilot study to identify genes associated with hepatic injury and fibrosis on liver biopsy that may help elucidate determinants of CF-associated liver disease (CFLD). METHODS: Liver tissue from children with CFLD with various stages of hepatic fibrosis was compared with pediatric controls using cDNA array analysis. Differential expression of genes of interest was then assessed relative to pediatric control liver and non-CF cholestatic disease control liver from patients with biliary atresia, using both real-time reverse transcription-polymerase chain reaction and immunohistochemistry. RESULTS: cDNA array demonstrated differential expression of numerous genes associated with hepatic fibrogenesis including collagens, matrix metalloproteinases, and chemokines in CFLD versus normal controls, particularly decreased expression in tissue remodeling genes including plasminogen activator inhibitor-1 (PAI-1, up to 25-fold) and tissue inhibitor of metalloproteinase-1 (TIMP-1); this was validated by real-time reverse transcription-polymerase chain reaction (PAI-1, P = 0.004; TIMP-1, P = 0.019). No significant decrease in PAI-1 or TIMP-1 mRNA was observed in biliary atresia versus normal control. Immunohistochemistry confirmed the decreased expression of hepatic PAI-1 and TIMP-1 protein in CFLD versus both normal and biliary atresia disease controls. CONCLUSIONS: The coordinated differential expression of these genes associated with liver fibrosis provides evidence for a transcriptional basis for the pathogenesis of CFLD and provides avenues for further study. Clarifying the pathogenesis of CFLD will facilitate techniques for early, precirrhotic detection and targeted interventions.

Management of excluded bile ducts in paediatric orthotopic liver transplant recipients of technical variant allografts.

BACKGROUND: A strategy to increase the number of size- and weight-appropriate organs and decrease the paediatric waiting list mortality is wider application of sectional orthotopic liver transplantation (OLT). These technical variants consist of living donor, deceased donor reduced and split allografts. However, these grafts have an increased risk of biliary complications. An unusual and complex biliary complication which can lead to graft loss is inadvertent exclusion of a major segmental bile duct. We present four cases and describe an algorithm to correct these complications. METHODS: A retrospective review of the paediatric orthotopic liver transplantation database (2000-2010) at Washington University in St. Louis/St. Louis Children's Hospital was conducted. RESULTS: Sixty-eight patients (55%) received technical variant allografts. Four complications of excluded segmental bile ducts were identified. Percutaneous cholangiography provided diagnostic confirmation and stabilization with external biliary drainage. All patients required interval surgical revision of their hepaticojejunostomy for definitive drainage. Indwelling biliary stents aided intra-operative localization of the excluded ducts. All allografts were salvaged. DISCUSSION: Aggressive diagnosis, percutaneous decompression and interval revision hepaticojejunostomy are the main tenets of management of an excluded bile duct. Careful revision hepaticojejunostomy over a percutaneous biliary stent can result in restoration of biliary continuity and allograft survival.

Genomic selection and complex trait prediction using a fast EM algorithm applied to genome-wide markers.

BACKGROUND: The information provided by dense genome-wide markers using high throughput technology is of considerable potential in human disease studies and livestock breeding programs. Genome-wide association studies relate individual single nucleotide polymorphisms (SNP) from dense SNP panels to individual measurements of complex traits, with the underlying assumption being that any association is caused by linkage disequilibrium (LD) between SNP and quantitative trait loci (QTL) affecting the trait. Often SNP are in genomic regions of no trait variation. Whole genome Bayesian models are an effective way of incorporating this and other important prior information into modelling. However a full Bayesian analysis is often not feasible due to the large computational time involved. RESULTS: This article proposes an expectation-maximization (EM) algorithm called emBayesB which allows only a proportion of SNP to be in LD with QTL and incorporates prior information about the distribution of SNP effects. The posterior probability of being in LD with at least one QTL is calculated for each SNP along with estimates of the hyperparameters for the mixture prior. A simulated example of genomic selection from an international workshop is used to demonstrate the features of the EM algorithm. The accuracy of prediction is comparable to a full Bayesian analysis but the EM algorithm is considerably faster. The EM algorithm was accurate in locating QTL which explained more than 1% of the total genetic variation. A computational algorithm for very large SNP panels is described. CONCLUSIONS: emBayesB is a fast and accurate EM algorithm for implementing genomic selection and predicting complex traits by mapping QTL in genome-wide dense SNP marker data. Its accuracy is similar to Bayesian methods but it takes only a fraction of the time.

Fibrogenesis in pediatric cholestatic liver disease: role of taurocholate and hepatocyte-derived monocyte chemotaxis protein-1 in hepatic stellate cell recruitment.

UNLABELLED: Cholestatic liver diseases, such as cystic fibrosis (CF) liver disease and biliary atresia, predominate as causes of childhood cirrhosis. Despite diverse etiologies, the stereotypic final pathway involves fibrogenesis where hepatic stellate cells (HSCs) are recruited, producing excess collagen which initiates biliary fibrosis. A possible molecular determinant of this recruitment, monocyte chemotaxis protein-1 (MCP-1), an HSC-responsive chemokine, was investigated in CF liver disease and biliary atresia. The bile-duct-ligated rat and in vitro coculture models of cholestatic liver injury were used to further explore the role of MCP-1 in HSC recruitment and proposed mechanism of induction via bile acids. In both CF liver disease and biliary atresia, elevated hepatic MCP-1 expression predominated in scar margin hepatocytes, closely associated with activated HSCs, and was also expressed in cholangiocytes. Serum MCP-1 was elevated during early fibrogenesis. Similar observations were made in bile-duct-ligated rat liver and serum. Hepatocytes isolated from cholestatic rats secreted increased MCP-1 which avidly recruited HSCs in coculture. This HSC chemotaxis was markedly inhibited in interventional studies using anti-MCP-1 neutralizing antibody. In CF liver disease, biliary MCP-1 was increased, positively correlating with levels of the hydrophobic bile acid, taurocholate. In cholestatic rats, increased MCP-1 positively correlated with taurocholate in serum and liver, and negatively correlated in bile. In normal human and rat hepatocytes, taurocholate induced MCP-1 expression. CONCLUSION: These observations support the hypothesis that up-regulation of hepatocyte-derived MCP-1, induced by bile acids, results in HSC recruitment in diverse causes of cholestatic liver injury, and is a key early event in liver fibrogenesis in these conditions. Therapies aimed at neutralizing MCP-1 or bile acids may help reduce fibro-obliterative liver injury in childhood cholestatic diseases.

Biliary strictures in pediatric liver transplant recipients - early diagnosis and treatment results in excellent graft outcomes.

Biliary complications in pediatric LT are important causes of morbidity and graft loss. We examined our recent pediatric LT experience to determine the outcome of post-LT biliary complications and their relationship to graft type. All initially isolated LTs performed at our institution between January 1, 2000 and August 20, 2007 were reviewed. Recipient data, donor type, graft survival, and biliary complications data were examined. Of 66 LTs, 32 patients received whole organ grafts, and 34 received partial grafts; 11 split, seven reduced size, and 16 live donors. Seventy-seven percent of patients had biliary reconstruction using a RYH. Overall, 17 (26%) developed biliary complications, and 15 were diagnosed within six months post-LT. Live donor and split allografts had more biliary complications than reduced size or whole allografts (50% and 36% vs. 0% and 16%, respectively). Seventy-one percent responded to percutaneous or endoscopic treatment. Five failed initial non-operative management and required reoperation (one retransplantation). These data suggest that biliary strictures occur most frequently in live donor and split allografts and that non-operative therapy is highly successful. Partial grafts are essential in pediatric LT, and a high clinical suspicion for biliary complications combined with aggressive and early diagnosis and therapy rarely results in graft loss.

Temperature-Dependent Blue Shifting of O-H Stretching Frequencies in Crystalline Cellulose Explained.

Increasing the temperature of a chemical system generally causes covalent bonds to lengthen and weaken, often the first step in initiating chemical reactions. However, for some hydrogen-bonded systems, infrared (IR) spectroscopy measurements reveal that covalent O-H bonds actually strengthen and therefore shorten when heated. In 1957, Finch and Lippincott proposed a simple one-dimensional (1D) model to explain this effect, in which thermal excitation of intermolecular stretching modes leads to lengthening and weakening of intermolecular O-H···O hydrogen bonds, thereby indirectly strengthening the associated covalent O-H bonds. Taking cellulose (an infinitely repeating polymer of d-glucose) as an example, we use molecular dynamics modeling to show that the same mechanism is responsible for temperature-dependent blue shifting of O-H stretching bands in IR spectra of carbohydrate biopolymers, except that interchain hydrogen bonds are weakened by thermal excitation of chain-separation modes, while intrachain hydrogen bonds are weakened by thermally induced changes in ring puckering and orientation of ring substituents but not reorientation of glucose units relative to one another or overall twisting of the cellulose chains.

A fast algorithm for BayesB type of prediction of genome-wide estimates of genetic value.

Genomic selection uses genome-wide dense SNP marker genotyping for the prediction of genetic values, and consists of two steps: (1) estimation of SNP effects, and (2) prediction of genetic value based on SNP genotypes and estimates of their effects. For the former step, BayesB type of estimators have been proposed, which assume a priori that many markers have no effects, and some have an effect coming from a gamma or exponential distribution, i.e. a fat-tailed distribution. Whilst such estimators have been developed using Monte Carlo Markov chain (MCMC), here we derive a much faster non-MCMC based estimator by analytically performing the required integrations. The accuracy of the genome-wide breeding value estimates was 0.011 (s.e. 0.005) lower than that of the MCMC based BayesB predictor, which may be because the integrations were performed one-by-one instead of for all SNPs simultaneously. The bias of the new method was opposite to that of the MCMC based BayesB, in that the new method underestimates the breeding values of the best selection candidates, whereas MCMC-BayesB overestimated their breeding values. The new method was computationally several orders of magnitude faster than MCMC based BayesB, which will mainly be advantageous in computer simulations of entire breeding schemes, in cross-validation testing, and practical schemes with frequent re-estimation of breeding values.

Serum alpha-NH-butyric acid may predict spontaneous survival in pediatric acute liver failure.

ALF is a serious, often fatal condition. Up to half of PALF patients do not survive without liver transplantation; however, early identification of those least likely to survive spontaneously remains difficult. Clinical experience suggests that recovery from ALF depends on the ability of the liver to regenerate. Based on this, we hypothesized that bio-markers of hepatic regeneration could have utility as predictors of recovery from PALF. In the studies reported here, we used comprehensive amino acid analysis to search for novel metabolomic markers of liver regeneration in mice subjected to partial hepatectomy. This analysis identified alpha-NH(2)-adipic acid and alpha-NH(2)-butyric acid as significantly increased in liver and plasma samples from mice subjected to partial hepatectomy compared to controls. Next, we tested whether serum levels of these markers were associated with clinical outcomes in PALF patients. This examination, performed on the initially collected serum samples from 40 randomly selected patients enrolled in the PALF Study Group, showed increased alpha-NH(2)-butyric-acid (Aab) and Aab:leucine (Aab:Leu) ratio in patients who survived without transplantation compared to those who were transplanted or died. These data indicate that Aab and the Aab:Leu ratio may predict clinical outcomes in PALF.

Towards minimizing immunosuppression in pediatric liver transplant recipients.

Immunosuppression regimens after liver transplantation focus mainly on preventing rejection and subsequent graft loss. However, in children, morbidity and mortality rates from infections exceed those from rejection after transplant, and immunosuppression can hinder growth, renal function, and graft tolerance. We hypothesized that early steroid withdrawal, with a primary aim of TAC monotherapy would yield no penalty in terms of rejection and graft loss, while reducing risks of infection and maximizing growth. We prospectively evaluated 64 consecutive pediatric liver transplant recipients. One yr patient/graft survival was 93/90%, respectively. At one yr post-transplant, 75.4% of patients were on TAC monotherapy. No deaths or graft losses were caused by infection. Sixty-one percent of patients had at least one episode of rejection, most within three months following transplant and 3.8% were treated for chronic rejection. One non-compliant adolescent died from chronic rejection. CMV, EBV, and lymphoproliferative disease rates were 3.1%, 5.3%, 1.8%, respectively. Pretransplant and one yr post-transplant glomerular filtration rates were unchanged. One yr improved catch-up growth was observed. We conclude that immunosuppression minimization after pediatric liver transplant yields no serious complications from rejection, and might confer advantages with respect to infection, renal function, growth, and is deserving of wider application and study.

Growth failure and outcomes in infants with biliary atresia: a report from the Biliary Atresia Research Consortium.

UNLABELLED: Malnutrition is a significant clinical problem in infants with biliary atresia. The natural history of poor growth and its potential association with early transplantation or death in children with biliary atresia was determined. Serial weight- and length-for-age z-scores were computed as part of a retrospective study of 100 infants who underwent hepatoportoenterostomy (HPE) for biliary atresia at 9 U.S. pediatric centers between 1997 and 2000. Poor outcome was defined as transplantation or death by 24 months of age (n = 46) and good outcome was defined as survival with native liver at 24 months of age with total serum bilirubin less than 6 mg/dL (n = 54). Growth velocity was significantly slower in the poor outcome group compared to the good outcome group (P < 0.001 for both weight and length). Mean weight z-scores were significantly lower by 6 months after HPE in the poor outcome group (-2.1 +/- 1.4) compared to the good outcome group (-1.2 +/- 1.4) (P < 0.001). In a subgroup with total bilirubin between 2 and 6 mg/dL at 3 months after HPE (n = 28), the weight z-scores at 3 months after HPE were significantly lower in the poor outcome group (-2.0 +/-1.2) compared to the good outcome group (-1.0 +/- 1.2) (P = 0.04) despite similar bilirubin concentrations. CONCLUSION: Growth failure after HPE was associated with transplantation or death by 24 months of age. The combination of intermediate bilirubin concentrations and poor mean weight z-scores 3 months after HPE was also associated with poor clinical outcome.