Biliary atresia and other cholestatic childhood diseases: Advances and future challenges.

Biliary Atresia and other cholestatic childhood diseases are rare conditions affecting the function and/or anatomy along the canalicular-bile duct continuum, characterised by onset of persistent cholestatic jaundice during the neonatal period. Biliary atresia (BA) is the most common among these, but still has an incidence of only 1 in 10-19,000 in Europe and North America. Other diseases such as the genetic conditions, Alagille syndrome (ALGS) and Progressive Familial Intrahepatic Cholestasis (PFIC), are less common. Choledochal malformations are amenable to surgical correction and require a high index of suspicion. The low incidence of such diseases hinder patient-based studies that include large cohorts, while the limited numbers of animal models of disease that recapitulate the spectrum of disease phenotypes hinders both basic research and the development of new treatments. Despite their individual rarity, collectively BA and other cholestatic childhood diseases are the commonest indications for liver transplantation during childhood. Here, we review the recent advances in basic research and clinical progress in these diseases, as well as the research needs. For the various diseases, we formulate current key questions and controversies and identify top priorities to guide future research.

Liver transplantation for hepatoblastoma.

From October 1993 to February 2007, 25 liver transplantations were performed for hepatoblastoma. Of these 25, 18 children received cadaveric grafts, and 7 received left lateral segments from living donors. Fifteen patients were at level IV in the pretreatment extent of disease staging system for hepatoblastoma (PRETEXT IV; 11 received cadaveric grafts and 4 underwent living related liver transplantation [LRLT]) and 10 were level III (PRETEXT III; 7 received cadaveric grafts and 3 underwent LRLT). Preoperative chemotherapy was given according to the risk stratification system for children with hepatoblastoma protocols of the International Childhood Liver Tumour Strategy Group of the International Society of Paediatric Oncology (SIOPEL): SIOPEL I in the first 3 patients, SIOPEL II in 6, SIOPEL III in 10, and SIOPEL IV in 3 patients. Patient and graft survival after cadaveric transplantation was 91%, 77.6%, and 77.6%, at 1, 5, and 10 years, respectively, with no retransplantations. Patient and graft survival for children undergoing LRLT was 100%, 83.3%, and 83.3%, at 1, 5, and 10 years, respectively. All surviving children but 1 remain disease-free, with a median follow up of 6.8 years (range, 0.9-14.9). There were 5 deaths at a median of 13 months post-transplantation, secondary to tumor recurrence (4) and respiratory failure (1). Liver transplantation is an established treatment for unresectable hepatoblastoma confined to the liver following chemotherapy. LRLT is a therapeutic option given that the outcome is similar to that of resection and cadaveric transplantation.

Mycophenolic acid and mycophenolic acid glucuronide pharmacokinetics in pediatric liver transplant recipients: effect of cyclosporine and tacrolimus comedication.

Determinants of the wide interindividual variability of the pharmacokinetics of mycophenolic acid (MPA) in 21 stable pediatric liver transplant recipients were investigated in relation to the kinetics of the drug's major phenolic glucuronide metabolite (MPAG), cyclosporin (CsA), or tacrolimus (Tac) co-medication and liver and renal function. Trough concentrations (C(0) ) most reliably predicted the area under the curve (AUC) of 0-7 hours MPA plasma concentrations (r (2) = 0.650). Co-medication with CsA demanded higher MPA mofetil (MMF) doses to achieve equivalent trough levels than Tac (362 vs. 178 mg per mg/L, P= 0.004). Median MPA C(0) (range) was significantly lower during CsA co-therapy when corrected for MMF dose (2.8 vs. 5.6 mg MPA/L for Tac, P= 0.006). The AUC of MPAG was correspondingly higher during CsA co-medication (229 vs. 94 mg/L/h for Tac, P = 0.012) with the MPA-to-MPAG ratio at C(0) correspondingly lower (0.10 vs. 0.14, respectively, P = 0.04). This suggested contrasting effects of CsA and Tac on MPA glucuronidation or its excretion and enterohepatic recirculation. MPAG AUC was correlated to body weight and creatinine clearance. Children with elevated aspartate transaminase (AST; but with no evidence of rejection on liver biopsy, n = 7) had significantly lower MPA trough levels compared with those in whom AST was normal (0. 77 vs. 1.76 mg/L, P = 0.05), but there was no difference in the MMF dose per body weight. Examination of the MPA profiles in these subjects showed significantly lower MPA concentrations from 120 minutes after dose until the end of the 7-hour profile and suggest an accelerated clearance or decreased enterohepatic recirculation.)

Diagnosis and phenotypic classification of Wilson disease.

Wilson disease is an inherited autosomal recessive disorder of hepatic copper metabolism leading to copper accumulation in hepatocytes and in extrahepatic organs such as the brain and the cornea. Originally Wilson disease was described as a neurodegerative disorder associated with cirrhosis of the liver. Later, Wilson disease was observed in children and adolescents presenting with acute or chronic liver disease without any neurologic symptoms. While diagnosis of neurologic Wilson disease is straightforward, it may be quite difficult in non-neurologic cases. Up to now, no single diagnostic test can exclude or confirm Wilson disease with 100% certainty. In 1993, the gene responsible for Wilson disease was cloned and localized on chromosome 13q14.3 (MIM277900) (1, 2). The Wilson disease gene ATP7B encodes a P-type ATPase. More than 200 disease causing mutations of this gene have been described so far (3). Most of these mutations occur in single families, only a few are more frequent (like H1069Q, 3400delC and 2299insC in Caucasian (4-6) or R778L in Japanese (7), Chinese and Korean patients). Studies of phenotype-genotype relations are hampered by the lack of standard diagnostic criteria and phenotypic classifications. To overcome this problem, a working party discussed these problems in depth at the 8th International Meeting on Wilson disease and Menkes disease in Leipzig/Germany (April 16-18, 2001). After the meeting, a preliminary draft of a consensus report was mailed to all active participants and their comments were incorporated in the final text.