Cyclosporine A disposition, hepatic and renal tolerance in Wistar rat

Cyclosporine A, a potent calcineurin inhibitor, has been widely used in organ transplantation and in the treatment of autoimmune diseases. It has, however, been shown to induce serious renal and hepatic side effects. The drug is also used in preclinical studies, but with little published information on the optimal dose and route of administration in rodents. Objectives of this study were to identify efficient and safe doses of cyclosporine A in rodent and to assess its effects on hepatic and renal functions. For this purpose, we tested the effects of different doses and administration routes of cyclosporine A (5, 2.5 and 1 mg/kg) administered during 28 days intraperitoneally, or by gastric feeding on Wistar rats. Our data indicate that rats injected intraperitoneally with 5 mg/kg/2d (every two days) exhibited trough cyclosporine A levels within known therapeutic range in human, but were subject to blood cyclosporine A accumulation, whereas the 5 mg/kg/d gavage resulted in only a small cyclosporine A accumulation over time. In both cases this accumulation was not deleterious to renal and hepatic functions, as shown by transaminase, urea, creatinine and bilirubin measurements.

Progressive Fibrosis Is Driven by Genetic Predisposition, Allo-immunity, and Inflammation in Pediatric Liver Transplant Recipients

Aim

To determine predisposing factors of idiopathic allograft fibrosis among pediatric liver transplant recipients.

Background

Protocol biopsies (PB) from stable liver transplant (LT) recipient children frequently exhibit idiopathic fibrosis. The relation between allograft inflammation, humoral immune response and fibrosis is uncertain. Also the role of HLA-DRB1 genotype has not been evaluated, though it's associated with fibrosis in autoimmune hepatitis.

Patients and Methods

This observational study, included 89 stable LT recipient transplanted between 2004–2012 with mean follow-up of 4.3 years, 281 serial PBs (3.1 biopsy/child) and human leukocyte antigen (HLA) antibody data. PBs were taken 1–2, 2–3, 3–5, 5–7, and 7–10 years post-LT, and evaluated for inflammation and fibrosis using liver allograft fibrosis score (LAFSc). The evolution of fibrosis, inflammation and related predisposing factors were analysed.

Findings

HLA-DRB1*03/04 allele and Class II DSA were significantly associated with portal fibrosis (p = 0.03; p = 0.03, respectively). Portal inflammation was predisposed by Class II DSA (p = 0.02) and non-HLA antibody presence (p = 0.01). Non-portal fibrosis wasn't predisposed by inflammation. Lobular inflammation was associated with non-HLA antibodies.

Interpretation

We conclusively demonstrated that allograft inflammation results in fibrosis and is associated with post-LT Class II DSA and non-HLA antibodies. The HLA-DRB1*03/04 allele caused genetic predisposition for fibrosis.

Funding

None.

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There is a link between genetic predisposition, alloimmune antibodies, allograft inflammation and fibrosis

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Description of allograft natural history by assessing evolution of inflammation, fibrosis in different histological zones

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Allograft inflammation results in allograft fibrosis and is associated with post-LT Class II DSA and non-HLA antibodies

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The HLA-DRB1*03/04 allele causes genetic predisposition for fibrosis

Among pediatric liver transplant recipients, the graft longevity is expected to parallel the life expectancy of the recipient. A major impediment in this is progressive allograft fibrosis, the cause of which is not well understood. If this pathogenesis could be found, then interventions to arrest the progressive fibrosis could be explored. In our 89 patients for whom we did periodic surveillance liver biopsies, inflammation was found to precede the fibrosis and associated with presence of specific antibodies. Certain genetic predisposition for higher fibrogenesis was also found, thus establishing a link between genetic predisposition, alloimmune response, inflammation, and allograft fibrosis.

Mesenchymal stem cell treatment for hemophilia: a review of current knowledge

Hemophilia remains a non-curative disease, and patients are constrained to undergo repeated injections of clotting factors. In contrast, the sustained production of endogenous factors VIII (FVIII) or IX (FIX) by the patient's own cells could represent a curative treatment. Gene therapy has thus provided new hope for these patients. However, the issues surrounding the durability of expression and immune responses against gene transfer vectors remain. Cell therapy, involving stem cells expanded in vitro, can provide de novo protein synthesis and, if implanted successfully, could induce a steady-state production of low quantities of factors, which may keep the patient above the level required to prevent spontaneous bleeding. Liver-derived stem cells are already being assessed in clinical trials for inborn errors of metabolism and, in view of their capacity to produce FVIII and FIX in cell culture, they are now also being considered for clinical application in hemophilia patients.

Hepatocyte Transplantation Using the Domino Concept in a Child with Tetrabiopterin Nonresponsive Phenylketonuria

Phenylketonuria is a metabolic disease caused by phenylalanine hydroxylase deficiency. Treatment is based on a strict natural protein-restricted diet that is associated with the risk of malnutrition and severe psychosocial burden. Oral administration of tetrahydrobiopterin can increase residual enzyme activity, but most patients with severe clinical phenotypes are nonresponders. We performed liver cell transplantation in a 6-year-old boy with severe tetrahydrobiopterin nonresponsive phenylketonuria who failed to comply with diet prescriptions. The transplanted hepatocytes were obtained in part from an explanted glycogen storage type 1b liver. Following two infusions, blood phenylalanine levels returned within the therapeutic target while the phenylalanine half-life assessed by loading tests decreased from 43 to 19 h. However, 3 months later, blood phenylalanine concentrations increased and the phenylalanine intake had to be reduced. Cell-based therapy is a promising therapeutic option in phenylketonuria, and the domino concept may solve the issue of cell sources for hepatocyte transplantation.

From hepatocytes to stem and progenitor cells for liver regenerative medicine: advances and clinical perspectives

The parenchymal liver cell is a unique fully functional metabolic unit that can be used for liver regenerative medicine to restore function of the diseased organ; the aim of the procedure is to prevent progression of end-stage disease. The alternative, orthotopic liver transplantation, is highly intrusive, irreversible and limited by general organ shortage. Mature liver cell - hepatocyte - transplantation has been shown to have short- to medium-term efficacy for correction of miscellaneous inborn errors of metabolism. However, although proof of concept has been established, the procedure has not yet achieved full success, due to limited durability of functional benefit. Hepatocyte procurement is also restricted by organ shortage, and their storage is difficult due to poor tolerance of cryopreservation. Alternative cell sources are therefore needed for development and wider accessibility of cell-based liver regenerative medicine. Besides safety, the main challenge for these alternative cells is to acquire similar levels of functionality once implanted into the target organ. In this respect, liver derived progenitor cells may have some advantages over stem cells derived from other tissues.

The interferon-alpha and interleukin-10 responses in neonates differ from adults, and their production remains partial throughout the first 18 months of life

Previous studies have suggested that the susceptibility of newborns to infections is linked to the immaturity of their immune system, but very few data are available on the early stages of maturation of the immune response. Therefore, we decided to investigate the evolution of the interferon (IFN)-α and interleukin (IL)-10 responses in neonatal mononuclear cells. To this end, mononuclear cells isolated from cord blood and peripheral blood of 2-, 6- and 18-month-old children and adults were stimulated with unmethylated cytosine-phosphate-guanosine oligodeoxynucleotide (CpG-ODN) 2216 (IFN-α response) or lipopolysaccharide (LPS) (IL-10 response) for 24 h. The production of IFN-α and IL-10 was then measured in culture supernatants using enzyme-linked immunosorbent assay (ELISA) or a 6-plex cytokine array, respectively. Compared to adults, we found a significant impairment in both the IFN-α and IL-10 responses of neonatal mononuclear cells. Interestingly, both responses had increased significantly after 2 months, but remained lower than the adult responses throughout the first 18 months of life. This study shows that although the immune response of neonates tends to mature fairly quickly, it remains different when compared to the adult immune response throughout the first 18 months of life. This could have important consequences on children's ability to mount an appropriate immune response to various challenges and to establish tolerance and immune homeostasis.

[Regeneration of the liver: from hepatocyte cells to deficient hepatic cells]

Regenerative medicine aims to restore the function of a deficient organ without replacing it, i.e. without resection-transplantation, but by the use of healthy cells which will transfer the deficient function inside the diseased organ. Cells can be mature, harvested directly from the source tissue, or be instead produced from stem cells, which can be manipulated in vitro, expanded and/or differentiated to render them functional. Liver cell therapy has brought the proof of concept that a deficient metabolic activity can be transferred via transfusion of heterologous liver cells via the portal vein. The main limitations of the technique include organ shortage, poor renewal capacity of mature cells and poor resistance to cryopreservation. A liver derived progenitor cell has recently been identified in the adult human liver. The cell is selected by a culture process, can be expanded in vitro and differentiated into mature human hepatocytes when transplanted in rodent livers. The cell displays all the essential hepatocyte function, and may replace the mature hepatocyte for regenerative medicine of the liver.

Persistence of a chimerical phenotype after hepatocyte differentiation of human bone marrow mesenchymal stem cells

OBJECTIVES

Recent studies have suggested the potential of mesenchymal stem cells (MSCs) to differentiate into a hepatocyte-like lineage. Here, we evaluate the efficacy of hepatocyte differentiation of MSCs by studying acquisition of hepatocyte-like features together with alteration of the native mesenchymal phenotype.

MATERIAL AND METHODS

In vitro, we have investigated protein and mRNA level expression of hepatocyte and mesenchymal markers of mesenchymal-derived hepatocyte-like cells (MDHLCs) and we have evaluated their functionality using metabolic assays. In vivo, we investigated co-expression of hepatocyte (albumin, alpha-foetoprotein, cytokeratin 18) and mesenchymal (fibronectin, vimentin) markers after transplantation of MSCs or MDHLCs into severe combined immune deficiency mice.

RESULTS

We observed that while in vitro these cells acquired some phenotypic and functional features of mature hepatocytes, they partially preserved their mesenchymal phenotype. After intrasplenic transplantation, engrafted MSCs with isolated expression of fibronectin and alpha-foetoprotein were observed. When these cells were injected into the liver, they expressed all analysed markers, confirming the chimaeric co-expression observed in vitro. Conversely, liver-engrafted MDHLCs conserved their hepatocyte-lineage markers but lost their chimaeric phenotype.

CONCLUSIONS

Hepatocyte differentiation of MSCs predominantly allows the acquisition of phenotypic hallmarks and provides chimaeric cells that maintain expression of initial lineage markers. However, advanced maturation to the hepatocyte-like phenotype could be obtained in vivo by conditioning MSCs prior to transplantation or by infusing cells into the liver micro-environment.

Cell transplantation in the treatment of liver diseases

The liver performs multiple functions that are essential for life, the most crucial being its role in the body metabolism. Impairment of this function, because of liver insufficiency, can be partially restored by medical management but OLT remains the ultimate therapeutic treatment. Because not always indicated or available, other alternatives are proposed such as LCT. Compared to OLT, this procedure is less invasive, less expensive, and fully reversible. More than 50 patients have thus far benefited of this technique and are reviewed here. Indications were multiple including inborn errors of metabolism, FHF, acute on chronic diseases, and decompensated end-stage cirrhosis. Documented results were encouraging, especially for metabolic disorders, with medium-term efficacy up to two yr. Related complications were exceptional. On this basis, LCT has entered its phase of clinical application and current indications and protocols are detailed. Ongoing lines of research are discussed, including cell quality, stem cell field, and rejection prevention. Further improvement of the procedure is therefore expected and should lead to broader applications of LCT.

Effects of lowering the aluminium content of a dTpa vaccine on its immunogenicity and reactogenicity when given as a booster to adolescents

As aluminium in vaccines has been associated with the incidence of local side effects occurring after vaccination, this observer-blind randomised clinical trial was designed to evaluate the effect of lowering the aluminium content of a combined reduced-antigen-content dTpa vaccine on immunogenicity and safety when administered to healthy adolescents aged 10-18 years. A total of 647 subjects were enrolled, 224 (35%) received a dTpa formulation with 0.5 mg aluminium, 209 (32%) a formulation with 0.3 mg aluminium and 214 (33%) a formulation with 0.133 mg aluminium. One month after boostering, all subjects were seroprotected against diphtheria and tetanus toxoids. All subjects were seropositive for anti-FHA and anti-PRN but 4% of the initially seronegatives in both reduced aluminium groups did not seroconvert for anti-PT. Booster responses did not differ significantly between groups for any antibody, but post booster vaccination anti-PT GMC's differed significantly between groups and decreased when vaccine aluminium content decreased. No clear difference between study groups in local or general side effects was demonstrated. The most frequently reported symptoms after vaccination were injection site pain (89.5-90.7%), fatigue (42.1-47.4%) and headache (41.1-45.1%). This study showed that the aluminium content has a specific influence on the immunogenicity of this dTpa vaccine.

Fifteen years single center experience in the management of progressive familial intrahepatic cholestasis of infancy

Recent advances in genetics and in physiopathology of bile composition and excretion have clarified the understanding of progressive familial intrahepatic cholestasis (PFIC). The aim of the present study is to review the experience of our center in terms of diagnosis, management and outcome of 49 pediatric PFIC patients, belonging to the three classical subtypes described. We analyse the clinical, biological, and histological patterns and review the response to the medical and surgical treatment and the global outcome. The only clinical difference between the different subtypes of PFIC patients was the intensity of pruritus. Serum gamma-glutamyltransferase (GGT) and liver histology allowed to differentiate PFIC III from PFIC I and II patients. High levels of biliary bile acids in 2 low-GGT patients was associated with favourable outcome. Response to ursodeoxycholic acid (UDCA) varies from patient to patient and was not associated to a particular subtype of PFIC. In five patients of this cohort, external biliary diversion was performed without improvement. Transplantation is indicated whenever medical treatment fails to restore normal social life, growth and well being of the child and it is associated with excellent survival (> 90%).

Pediatric liver transplantation for biliary atresia: results of primary grafts in 328 recipients

PURPOSE

The purpose of this study was to assess the overall results of recipients undergoing transplantation for biliary atresia (BA), according to age, surgical techniques, and transplant eras, and to identify the prognostic factors affecting outcome.

METHODS

Between 1984 and 2000, 328 pediatric recipients with BA who underwent orthotopic liver transplantation (OLT) were reviewed. Median age at OLT was 1.5 years (range, 0.4-14.5 years). Kasai hepatoportoenterostomy (KHPE) had been previously performed in 285 (87%) children. Regarding surgical techniques, 125 (38%) children received a whole-liver graft, 128 (39%) received a reduced-size graft, 16 (5%) received a split-liver graft, and 59 (18%) received a living-related (LR) donor graft.

RESULTS

Overall actuarial patient survivals were 87%, 83%, and 81% at 1, 5, and 10 years, respectively. One-year patient survivals in children undergoing transplantation at the different age ranges were 85% (under 1 year), 86% (1-3 years), 83% (3-6 years), 100% (6-10 years), and 100% (beyond 10 years) (not significant). One-year patient survivals for the different transplant eras were 75% (1984-1988), 85% (1989-1992), 93% (1993-1996), and 98% (1997-2000) (P=0.0001). Multivariate analysis demonstrated that pretransplant recipient weight (P=0.004), indication for OLT (P=0.083), and age at OLT (P=0.024) predicted patient survival. The type of baseline calcineurin inhibitor (tacrolimus) and the age at OLT (beyond 6 years) were significantly associated with a better graft survival.

CONCLUSIONS

Best results in children undergoing transplantation beyond 6 years indicate the importance of performing a KHPE as the first therapeutic step in BA; innovative surgical techniques, particularly LR donor graft, allowed successful transplantation in infants with early failure of KHPE.

Epstein-Barr virus-related lymphoproliferation in children after liver transplant: role of immunity, diagnosis, and management

Tumor occurrence following immunosuppression remains a major concern in children after liver transplantation. More than 50% of these tumors belong to the post-transplant lymphoproliferative diseases (PTLD) and are diagnosed during childhood. These PTLD are mostly related to primary Epstein-Barr virus (EBV) infection and a heavy immunosuppressive regimen. Improvement in their prognosis was reached thanks to a better knowledge of their pathogenesis, risk factors and clinical presentation, linked probably to earlier management. However, their incidence remains stable (occurring in 5-15% of children after liver transplantation) despite different pre-emptive strategies based on these parameters. Moreover, acute graft rejection and subsequent risk of graft loss is a common side-effect of PTLD treatment. EBV viral load determination by quantitative polymerase chain reaction (PCR) is so far the only predictive marker proposed for PTLD prevention and PTLD treatment monitoring, although limited by a lack of specificity. New immunologic techniques have allowed the demonstration of a defect of the EBV-specific cellular immunity in the patients with PTLD. The level of immunity is correlated to the viral load and improves during recovery from PTLD. These recent findings add further knowledge to PTLD pathogenesis and management.

Efficacy of lamivudine for the treatment of hepatitis B virus infection after liver transplantation in children

BACKGROUND

There is at present very little information about hepatitis B virus (HBV) infection in children after liver transplantation. This is the first study to assess the safety and efficacy of lamivudine in this patient population.

METHODS

We describe three children aged 5-14 years who underwent liver transplantation for fulminant hepatitis A, hyperoxaluria, and cystic fibrosis. Despite adequate immunoprophylaxis, two of the children who were serum hepatitis B surface antigen-positive before transplantation (HBV DNA-negative by hybridization) had a reactivation of the disease, and one had a de novo HBV infection, at 12-18 months after transplantation. Lamivudine 3 mg/kg was administered on a compassionate-use basis for 14-36 months.

RESULTS

After 1 month of therapy, HBV DNA disappeared from the serum in all patients by hybridization and in two patients by polymerase chain reaction. In all three children, alanine transaminase levels normalized. One child developed lamivudine resistance after 22 months with no evidence of hepatic decompensation. Repeated liver histological studies revealed progression of hepatic fibrosis in one child. All children remained serum hepatitis B surface antigen- and hepatitis B e antigen-positive. No adverse effects of the drug were noted.

CONCLUSION

Lamivudine is beneficial and well tolerated in children with HBV infection after liver transplantation.

The wide spectrum of multidrug resistance 3 deficiency: from neonatal cholestasis to cirrhosis of adulthood

BACKGROUND & AIMS

We have specified the features of progressive familial intrahepatic cholestasis type 3 and investigated in 31 patients whether a defect of the multidrug resistance 3 gene (MDR3) underlies this phenotype.

METHODS

MDR3 sequencing, liver MDR3 immunohistochemistry, and biliary phospholipid dosage were performed.

RESULTS

Liver histology showed a pattern of biliary cirrhosis with patency of the biliary tree. Age at presentation ranged from the neonatal period to early adulthood. Sequence analysis revealed 16 different mutations in 17 patients. Mutations were identified on both alleles in 12 patients and only on 1 allele in 5. Four mutations lead to a frame shift, 2 are nonsense, and 10 are missense. An additional missense mutation probably representing a polymorphism was found in 5 patients. MDR3 mutations were associated with abnormal MDR3 canalicular staining and a low proportion of biliary phospholipids. Gallstones or episodes of cholestasis of pregnancy were found in patients or parents. Children with missense mutations had a less severe disease and more often a beneficial effect of ursodeoxycholic acid therapy.

CONCLUSIONS

At least one third of the patients with a progressive familial intrahepatic cholestasis type 3 phenotype have a proven defect of MDR3. This gene defect should also be considered in adult liver diseases.

Impact of chronic hepatitis B and interferon-alpha therapy on growth of children

Interferon-alpha (IFN) has been approved as treatment for children with chronic hepatitis B (CHB). The aims of this study were to assess the impact on children's growth of the disease itself and of IFN treatment. The growth of 142 children with CHB (70 IFN-treated, 72 untreated) was monitored for a minimum of one year. Regression analysis models were used to determine which of the variables most affected children's growth. After adjusting for racial differences, the population of 142 children with CHB had a mean baseline height for age percentile of 39 and a mean baseline weight for age percentile of 38, which were significantly different (P < 0.0001) from the 50th percentiles of their respective reference populations. The height for age Z score of untreated children was inversely correlated with serum hepatitis B virus DNA and aspartate aminotransferase levels, and the weight for age Z score was inversely correlated with serum hepatitis B virus DNA levels. While undergoing IFN therapy, children displayed a "U-shaped" growth pattern, such that height for age and weight for age Z scores at 3 or 6 months were lower than scores at baseline or 12 months. In this study the average child with CHB showed compromised growth even in the absence of IFN therapy. During IFN therapy, children's growth was temporarily disrupted.

Insulin signal transduction in rat small intestine: role of MAP kinases in expression of mucosal hydrolases

The postreceptor events regulating the signal of insulin downstream in rat intestinal cells have not yet been analyzed. Our objectives were to identify the nature of receptor substrates and phosphorylated proteins involved in the signaling of insulin and to investigate the mechanism(s) by which insulin enhances intestinal hydrolases. In response to insulin, the following proteins were rapidly phosphorylated on tyrosine residues: 1) insulin receptor substrates-1 (IRS-1), -2, and -4; 2) phospholipase C-isoenzyme-gamma; 3) the Ras-GTPase-activating protein (GAP) associated with Rho GAP and p62(Src); 4) the insulin receptor beta-subunit; 5) the p85 subunits of phosphatidylinositol 3-kinase (PI 3-kinase); 6) the Src homology 2 alpha-collagen protein; 7) protein kinase B; 8) mitogen-activated protein (MAP) kinase-1 and -2; and 9) growth receptor-bound protein-2. Compared with controls, insulin enhanced the intestinal activity of MAP kinase-2 and protein kinase B by two- and fivefold, respectively, but did not enhance p70/S6 ribosomal kinase. Administration of an antireceptor antibody or MAP-kinase inhibitor PD-98059 but not a PI 3-kinase inhibitor (wortmannin) to sucklings inhibited the effects of insulin on mucosal mass and enzyme expression. We conclude that normal rat enterocytes express all of the receptor substrates and mediators involved in different insulin signaling pathways and that receptor binding initiates a signal enhancing brush-border membrane hydrolase, which appears to be regulated by the cascade of MAP kinases but not by PI 3-kinase.

Statistical models for predicting response to interferon-alpha and spontaneous seroconversion in children with chronic hepatitis B

To develop prognostic models for identifying children with hepatitis B who are likely to respond to interferon-alpha (IFN-alpha) or to spontaneously seroconvert, we evaluated results of a multinational controlled trial comprising 70 children with chronic hepatitis B who received IFN-alpha and 74 children who did not receive therapy. Prognostic models were developed using SMILES (similarity of least squares), which is a data analysis network that incorporates multidimensional relationships in the clinical data of complex diseases. Commonly collected clinical data included age, gender, serum aminotransferase (aspartate aminotransferase [AST] and alanine aminotransferase [ALT]) and hepatitis B virus (HBV) DNA levels, and IFN-alpha dose. Additional data included pretreatment directional information (e.g. increases or decreases in serum aminotransferase and HBV DNA levels), liver biopsy results, race and transmission mode. Using data available prior to initiation of treatment, the SMILES models achieved prospective predictions of 89% for responders, 96% for non-responders, 100% for seroconverters and 93% for non-seroconverters. Although not predictive by themselves, the variables that had the greatest impact on predictions for IFN-alpha response were HBV DNA pretreatment direction, baseline HBV DNA, IFN-alpha dose and gender. The variables that had the greatest impact on predictions for spontaneous seroconversion were ALT pretreatment direction, baseline HBV DNA level, age and AST pretreatment direction. Therefore, these models may be useful in determining, in children with hepatitis B, the likelihood of response to IFN-alpha and spontaneous seroconversion.

A dose ranging study of the pharmacokinetics, safety, and preliminary efficacy of lamivudine in children and adolescents with chronic hepatitis B

Fifty-three patients with chronic hepatitis B and active viral replication were studied for 4 weeks while on treatment and for 12 weeks after treatment with the oral nucleoside analogue lamivudine. Children aged 2 to 12 years were randomized to receive twice-daily doses of 0.35, 1.5, or 4 mg of lamivudine solution per kg of body weight or once-daily doses of 3 mg of lamivudine solution per kg. Adolescents aged 13 to 17 years received lamivudine at 100 mg (as tablets). Blood samples for pharmacokinetic assay were taken on days 1 and 28. Lamivudine was rapidly absorbed following oral administration, with the maximum concentration in serum being reached 0.5 to 1 h postdosing. Apparent oral clearance (CL/F) was higher in younger children and decreased with age, with CL/F values for adolescents reaching those seen for adults by the age of 12. All doses produced a dramatic fall in serum hepatitis B virus (HBV) DNA levels, with a median reduction of >/=99.5% after 4 weeks of treatment and with the levels returning to the baseline levels posttreatment. The correlation of dose, area under the concentration-time curve (AUC), and changes in HBV DNA levels, as measured by the Chiron Quantiplex assay, showed maximal antiviral effects (99.9% inhibition and a reduction of the amount of HBV DNA of approximately 3 log(10)) at 3 mg/kg/day, with no discernible increase in effect seen whether the drug was given at 4 mg/kg twice daily or whether it was given once daily or twice daily. The limit of detection of the assay (2.5 pg/ml) was reached for some but not all patients across the dose ranges, with the smallest number (n = 2) of those having values negative by the Chiron Quantiplex assay being in the lowest-dose group. The 13- to 17-year-olds showed a similar overall response in terms of the HBV DNA level reduction compared to that for patients younger than age 13. Analysis of the same samples by PCR, which has a lower limit of sensitivity than the Chiron Quantiplex assay, also showed average drops in HBV DNA levels of about 3 log(10) at 4 weeks for patients for which the AUC was >/=4,000 ng. h/ml, confirming the conclusions given above. Lamivudine treatment was well tolerated at all doses, with no significant adverse events or laboratory data changes. On the basis of pharmacokinetic and pharmacodynamic data, a 3-mg/kg/day dose in children (ages 2 to 12 years) with chronic hepatitis B provides levels of exposure and trough concentrations similar to those seen in adults following the receipt of doses of 100 mg. The 100-mg dose is being evaluated in a large phase III study with HBV-infected pediatric patients.

Demonstration of McCune-Albright mutations in the liver of children with high gammaGT progressive cholestasis

Two patients presented with neonatal cholestasis and acholic stools as first manifestations of McCune-Albright syndrome. Both went through an extensive evaluation including an exploratory laparotomy with peroperative cholangiography which ruled out biliary atresia. One patient presented from the fourth month of life with the classical café-au-lait spots following Blaschko's lines, while less classical café-au-lait spots were seen in the second patient at the age of 4 years. Bone lesions were seen in one patient at the age of 2.5 years and in the other at the age of 4 years. Despite the severity of presentation, both patients cleared their jaundice within 6 months, but still had mild abnormalities of liver function tests. Both patients showed an activating mutation of codon 201 in the gene encoding the alpha-subunit of the G-protein that stimulates adenylcyclase in liver tissue, suggesting that this metabolic defect could be responsible for the cholestatic syndrome. Similar mutations have been found in other affected tissues in patients with the McCune-Albright syndrome. We propose that McCune-Albright syndrome be included in the list for differential diagnosis of neonatal cholestasis and chronic cholestasis of infancy, as a rare cause.

Characteristics of Epstein-Barr virus primary infection in pediatric liver transplant recipients

BACKGROUND/AIM

Pediatric liver transplant recipients are at high risk of Epstein-Barr virus infection. However the incidence of clinical symptoms and the graft function at the time of acute infection remains poorly documented. The aim of this study was to monitor the clinical and biochemical events associated with primary Epstein-Barr virus infection.

METHODS

Clinical and biological patterns associated with Epstein-Barr virus infection were prospectively searched in 38 liver transplanted children. Polymerase chain reaction and anti-Epstein-Barr virus IgM antibodies were used at regular intervals to detect the timing of primary infection.

RESULTS

Five children (13%) had pretransplant immunity, 26 (68.5%) developed primary Epstein-Barr virus infection 15 to 90 days after transplantation and seven (18.5%) remained Epstein-Barr virus negative. The four patients with clinical symptoms at the time of infection subsequently developed post-transplant lymphoproliferative disease. A single post-transplant lymphoproliferative disease occurred in non-symptomatic patients (overall incidence 13%). No mortality was associated with post-transplant lymphoproliferative disease. Two asymptomatic patients had abnormal liver function tests possibly related to primary Epstein-Barr virus infection.

CONCLUSION

Epstein-Barr virus primary infection occurs in 80% of seronegative patients within 3 months after OLT. Clinical symptoms are rare and closely associated with post-transplant lymphoproliferative disease. Outside post-transplant lymphoproliferative disease, the consequences of infection are marginal.

Sclerosing cholangitis associated to cryptosporidiosis in liver-transplanted children

Three children of a series of 461 pediatric liver transplant recipients developed diffuse cholangitis associated with intestinal cryptosporidium carriage. All three received immunosuppression consisting of tacrolimus and prednisone. Cryprosporidium carriage was treated with paramomycin, while immunosuppression was decreased according to graft tolerance. No other infectious pathogens were found, and no vascular problems were detected. Bile duct anastomosis was reoperated in all three, but biliary cirrhosis developed in one patient, requiring retransplantation. All three patients are alive and well, and free of intestinal parasites on follow-up.

CONCLUSION

Cryptosporidium intestinal infection may play a role in some cases of otherwise unexplained cholangiopathies in pediatric liver transplant recipients. This may lead to significant morbidity, including need for retransplantation.

Hepatocanalicular bile salt export pump deficiency in patients with progressive familial intrahepatic cholestasis

BACKGROUND & AIMS

Progressive familial intrahepatic cholestasis (PFIC), an inherited liver disease of childhood, is characterized by cholestasis and either normal or increased serum gamma-glutamyltransferase activity. Patients with normal gamma-glutamyltransferase activity have mutations of the FIC1 locus on chromosome 18q21 or mutations of the BSEP gene on chromosome 2q24. Also, patients with bile acid synthesis defects have low gamma-glutamyltransferase activity. We investigated expression of the bile salt export pump (BSEP) in liver samples from patients with a PFIC phenotype and correlated this with BSEP gene mutations.

METHODS

BSEP and multidrug resistance protein 2 (MRP2) expressions were studied by immunohistochemistry in liver specimens of 28 patients and BSEP gene mutation analysis in 19 patients. Bile salt kinetics were studied in 1 patient.

RESULTS

Sixteen of 28 liver samples showed no canalicular BSEP staining. Staining for MRP2 showed a normal canalicular pattern in all but 1 of these samples. Ten of 19 patients showed BSEP gene mutations; BSEP protein expression was lacking in all 10 patients. No mutations were found in 9 of 19 patients, and in all except 1, BSEP protein expression was normal. Bile salt concentration in bile of BSEP-negative/MRP2-positive PFIC patients was 0.2 +/- 0.2 mmol/L (n = 9; <1% of normal) and in BSEP-positive PFIC patients 18.1 +/- 9.9 mmol/L (n = 3; 40% of normal). The kinetic study confirmed the dramatic decrease of bile salt secretion in BSEP-negative patients.

CONCLUSIONS

The findings show a close correlation between BSEP gene mutations and canalicular BSEP expression. Biliary secretion of bile salts is greatly reduced in BSEP-negative patients.

Liver transplantation in mitochondrial respiratory chain disorders

Mitochondrial respiratory chain disease may lead to neonatal or late onset liver failure, requiring liver transplantation. In rare cases, the disease is restricted to the liver and the patient is cured after surgery. More frequently, other organs are simultaneously involved and neuromuscular or other extra-hepatic symptoms may pre-exist, or appear in the post-transplant follow up. Pre-transplant evaluation should aim to rule out neurological disease, which may be difficult to differentiate from signs accompanying liver insufficiency. Cerebrospinal fluid lactic acid levels, compared to blood lactate, may be suggestive of central nervous system involvement. Of 11 cases with respiratory chain disorders who had liver transplantation in various centres, 4 are alive and well on follow up, and 6 died, three of them having developed neurological disease post orthotopic liver transplantation. All three patients with initial liver and gastro-intestinal disease died early after transplantation, indicating that these may be poor candidates for this procedure.

CONCLUSION

Liver transplantation is feasible in hepatic respiratory chain disorders, but extra-hepatic disease should be ruled out before transplantation. Extra-hepatic manifestations may, however, appear and cause patient death despite successful transplantation.

Update on prevention and treatment of viral hepatitis in children

Viral hepatitis is a persisting concern. Outbreaks of hepatitis A occur in developed countries where only 10% to 20% of the population is seroprotected. The disease may cause fulminant liver failure and death. People who are targeted for vaccination include intravenous drug users, homosexuals, and chronic hepatitis patients. Secondary prophylaxis of household contacts is an efficient way to prevent secondary cases. Universal vaccination is now in progress for hepatitis B. Vaccination failure may occur in low birth weight infants, or in infants infected in utero. Chronic carriers of viral hepatitis may progress to cirrhosis and hepatocarcinoma, the latter risk being most important for men infected at birth. Alcohol intake should be avoided in carrier adolescents. Interferon is able to triple the rate of hepatitis B e antigen loss and decouple the rate of hepatitis B s antigen loss after one year, shortening disease evolution and, it is to be hoped, decreasing the risk of unfavorable outcome. Similarly, lamivudine increases by four times the rate of hepatitis B e antigen loss in adults. However, precore mutants may be selected by immune pressure after seroconversion in children, and tyrosine-methionine-aspartate-aspartate (YMDD) mutations appear in 15% of patients treated with lamivudine after 1 year. Hepatitis C is mainly acquired during childhood via true vertical transmission. The risk of acquiring Hepatitis C is related to the presence and amount of RNA for hepatitis C virus in mothers at the time of birth. The infection rate for the hepatitis C virus is higher in children from mothers who have tested positive for HIV, and higher if these children are themselves coinfected with HIV. Treatment with interferon alone has a poor rate of efficiency, although pediatric studies remain scarce. Combination treatment using ribavirin plus interferon yield a higher rate of success in eradicating viral infection in adults.

Treatment of extrahepatic portal hypertension in children by mesenteric-to-left portal vein bypass: a new physiological procedure

OBJECTIVE

To achieve hepatic portal revascularisation and decompression of extrahepatic portal hypertension in children with cavernoma and obstruction caused by idiopathic portal vein thrombosis.

DESIGN

Selected cases.

SETTING

Teaching hospitals. Belgium and Italy.

SUBJECTS

11 children who weighed between 5.9 and 54 kg (2 emergencies) with symptomatic extrahepatic portal hypertension.

INTERVENTION

Interposition of venous autograft between the superior mesenteric vein and the distal (umbilical) portion of the left portal vein.

MAIN OUTCOME MEASURES

Improvements in symptoms and endoscopic appearance after operation.

RESULTS

2 bypasses had to be redone because they stenosed; all 11 were patent at the time of writing (median follow-up 6 months, range 1-32 months).

CONCLUSION

The bypass effectively relieved symptoms of extrahepatic portal hypertension by restoring normal hepatic portal blood flow.

Saccharomyces boulardii upgrades cellular adaptation after proximal enterectomy in rats

BACKGROUND

Saccharomyces boulardii is a non-pathogenic yeast which exerts trophic effects on human and rat small intestinal mucosa.

AIMS

To examine the effects of S boulardii on ileal adaptation after proximal enterectomy in rats.

METHODS

Wistar rats, aged eight weeks, underwent 60% proximal resection or transection and received by orogastric intubation either 1 mg/g body wt per day lyophilised S boulardii or the vehicle for seven days. The effects on ileal mucosal adaptation were assessed eight days after surgery.

RESULTS

Compared with transection, resection resulted in mucosal hyperplasia with significant decreases in the specific and total activities of sucrase, lactase, and maltase. Treatment of resected animals with S boulardii had no effect on mucosal hyperplasia but did upgrade disaccharidase activities to the levels of the transected group. Enzyme stimulation by S boulardii was associated with significant increases in diamine oxidase activity and mucosal polyamine concentrations. Likewise, sodium dependent D-glucose uptake by brush border membrane vesicles, measured as a function of time and glucose concentration in the incubation medium, was significantly (p<0.05) increased by 81% and three times respectively in the resected group treated with S boulardii. In agreement with this, expression of the sodium/glucose cotransporter-1 in brush border membranes of resected rats treated with S boulardii was enhanced twofold compared with resected controls.

CONCLUSION

Oral administration of S boulardii soon after proximal enterectomy improves functional adaptation of the remnant ileum.

Acute parvovirus B19 infection associated with fulminant hepatitis of favourable prognosis in young children

BACKGROUND

The cause of fulminant hepatitis (FH) in children is unexplained in up to 50% of cases. We report parvovirus B19 as an agent associated with FH in children and compare clinical characteristics of these patients with those of age-matched patients with FH of other origin.

METHODS

45 patients presented with FH. No cause was apparent in 21 patients. Parvovirus B19 genome was retrospectively sought by PCR in serum collected at admission in 41 patients.

FINDINGS

Parvovirus B19 genome was detected in serum from four of 21 patients with unexplained FH (four of 11 younger than 5 years). No B19 DNA was detected in serum from patients with other types of FH or from 82 patients with biliary atresia. Parvovirus B19 IgM was detected in one of the four patients. Patients with parvovirus B19 infection had significantly lower bilirubin concentrations than age-matched patients with FH due to hepatitis A (nine) or other causes (nine) (poisoning with amanita excluded). All patients with parvovirus B19 survived without orthotopic liver transplantation, with restoration of normal liver function within 17 days.

INTERPRETATION

In patients younger than 5 years with FH of unexplained origin, evidence of acute parvovirus B19 was associated with a distinct clinical pattern. In particular, low bilirubin concentrations and rapid recovery of liver function without transplantation were distinctive features.

Use of granulocyte macrophage colony stimulating factor in children after orthotopic liver transplantation

BACKGROUND/AIMS

Bacterial infections complicate the course of up to 80% of pediatric liver transplant recipients, and in some cases, neutropenia, surgical complications and/or antibiotic resistance prevent successful control of sepsis. The aim of the present study was to evaluate the safety and efficacy of granulocyte macrophage colony stimulating factors (GM-CSF) in treating neutropenia following pediatric orthotopic liver transplantation.

METHODS

Among a cohort of 430 pediatric orthotopic liver transplantation recipients, 13 children (12 months to 15 years, median 2 years, 10 males) received 15 courses of GM-CSF, 5 microg x kg(-1) x d(-1) subcutaneously, during their post-transplant course. In nine cases, the initial neutrophil count was below 1000/mm3. Ten patients were infected. Three received GM-CSF for severe sepsis without neutropenia. The mean duration of treatment was 16.3 days (range 4-49).

RESULTS

In all but one neutropenic patient the neutrophil count increased above 1500/mm3 and the mean neutrophil count increased from 1392+/-1912/mm3 (range 130-7170, median 640) to 4508+/-2459/mm3 (range 350-9630, median 4390) (p<0.01). Only one neutropenic patient (FK506 related) failed to respond to treatment. No rejection episode was induced by treatment, no side effects were noted, and patients with sepsis were cured.

CONCLUSION

In these patients, GM-CSF was safe, it achieved a significant increase in neutrophilic count, and was beneficial in patients with severe bacterial infections. This compound may prevent infectious complications in neutropenic patients and may benefit patients with severe sepsis with or without neutropenia.

Interferon alfa therapy for chronic hepatitis B in children: a multinational randomized controlled trial

BACKGROUND & AIMS

Treatment of chronic hepatitis B with interferon alfa is not approved in children. The aim of this study was to evaluate the safety and efficacy of interferon alfa (IFN-alpha) in children with chronic hepatitis B and increased transaminase levels.

METHODS

Children were given either IFN-alpha2b (6 megaunits/m2 thrice weekly for 24 weeks) or no treatment. Clearance of markers of viral replication was evaluated 24 weeks after therapy and after 48 weeks of observation in controls.

RESULTS

Of 149 children enrolled, 144 were evaluable (70 treated and 74 controls). Serum hepatitis B e antigen and viral DNA became negative in 26% of treated children and 11% of controls (P < 0.05). Serum aminotransferase levels normalized and liver histology improved among responders. Hepatitis B surface antigen became undetectable in 10% of treated patients and 1% of controls. Female gender and interferon treatment were the only significant predictors of response. Ethnic origin, baseline aminotransferase level, initial DNA levels, and histology did not correlate with response. Most adverse reactions were mild or moderate, and dose was reduced in 24% of children.

CONCLUSIONS

In children with chronic hepatitis B, INF-alpha promotes loss of viral replication markers and surface antigen and improves aminotransferases and histology.

Premature stimulation of rat sucrase-isomaltase (SI) by exogenous insulin and the analog B-Asp10 is regulated by a receptor-mediated signal triggering SI gene transcription

The mechanism(s) by which insulin enhance prematurely the activity of brush border membrane (BBM) hydrolases in rat immature intestine is unknown. Therefore, we have compared the responses of four BBM enzymes [sucrase-isomaltase (SI), maltase, lactase-phloridzine hydrolase (LPH), and aminopeptidase] with exogenous insulin, the analog B-Asp10, IGF-I, and antireceptor MAb [insulin-receptor (IR) MAb] given to preweaning pups. Low doses of insulin caused a precocious induction of SI and of SI mRNA and stimulated maltase activity without effect on LPH nor on aminopeptidase activities. IGF-I given at the same dose as that of insulin had no detectable effect on these enzymes. Administration to sucklings of IR MAb prevented the effect of endogenous insulin by inhibiting the expression of SI and maltase without effect on LPH activity. B-Asp10, an insulin analogue that exhibits in vitro a 3.5-fold increase in receptor affinity with sustained signaling of the receptor tyrosine kinase, caused an overexpression of SI by 3.5-fold and of maltase by 1.5-fold compared with equivalent doses of normal insulin. The premature increases in SI activity, SI mRNA, and maltase activity in response to insulin were dose-dependent and were associated with dose-dependent increases in intracellular spermine and spermidine concentrations. In conclusion, these data suggest that the premature induction of SI by insulin is mediated by a dose-dependent signal initiated by binding of the hormone to its intestinal receptor, which after transduction into the cell indirectly triggers the transcription of the SI gene, possibly by changes in intracellular polyamine concentrations.

Delayed primary closure of the abdominal wall after cadaveric and living related donor liver graft transplantation in children: a safe and useful technique

Due to the shortage of size-matched liver donors, relatively oversized liver grafts (even after ex situ volume reduction) are frequently used for liver transplantation in children. This was recently observed when livers from large, living related donors were procured for transplantation in very small recipients. Given that abdominal hyperpressure can compromise vascular flow in the new graft, primary closure of the abdomen was delayed by temporary Silastic prosthetic closure in selected cases. The new technique was original in that the skin was closed, avoiding fluid loss and reducing the risk of infections reported with other techniques, and in that reoperation allowed for a delayed, but primary-type, closure (fascia and skin) that resulted in an esthetically correct aspect. Over a period of 7 years, 330 pediatric liver transplantations were performed, and delayed prosthetic closure was achieved successfully and safely in 47 cases. The present report outlines this clinical experience.

Direct bypassing of extrahepatic portal venous obstruction in children: a new technique for combined hepatic portal revascularization and treatment of extrahepatic portal hypertension

BACKGROUND

Decompression of extrahepatic portal hypertension by directly bypassing the thrombosed portal vein has never been reported in cases of children with idiopathic (or neonatal) portal vein obstruction and cavernoma.

METHODS

Seven children (15 years or younger) with portal vein obstruction requiring surgical decompression (urgently in two cases), and in whom preoperative Doppler had shown that the intrahepatic portal branches were hypoplastic but free of thrombus, were included in a pilot study. The cavernoma was bypassed by interposing a venous jugular autograft between the superior mesenteric vein and the distal portion of the left portal vein. Patients received follow-up using routine clinical parameters, upper gastrointestinal endoscopy, and Doppler ultrasound.

RESULTS

The mesenterico-portal bypass restored a direct (physiological) hepatopetal portal flow. The operation resulted in effective portal decompression as demonstrated by decrease of the pressure gradient, rapid regression of clinical signs of portal hypertension, and definitive control of bleeding.

CONCLUSIONS

This study shows that direct bypassing of portal cavernoma is possible and results in effective portal decompression. Restoration of the hepatic portal flow is a major advantage compared with conventional surgical shunting procedures. This new technique is potentially applicable to two thirds of children with portal vein thrombosis and should be considered when shunting procedures are indicated.

Repeated-dose pharmacokinetics of an oral solution of itraconazole in infants and children

The safety, tolerability, and pharmacokinetics of an oral solution of itraconazole and its active metabolite hydroxyitraconazole were investigated in an open multicenter study of 26 infants and children aged 6 months to 12 years with documented mucosal fungal infections or at risk for the development of invasive fungal disease. The most frequent underlying illness was acute lymphoblastic leukemia, except in the patients aged 6 months to 2 years, of whom six were liver transplant recipients. The patients were treated with itraconazole at a dosage of 5 mg/kg of body weight once daily for 2 weeks. Blood samples were taken after the first dose, during treatment, and up to 8 days after the last itraconazole dose. On day 1, the mean peak concentrations in plasma after the first and last doses (Cmax) and areas under the concentration-time curve from 0 to 24 h (AUC0-24) for itraconazole and hydroxyitraconazole were lower in the children aged 6 months to 2 years than in children aged 2 to 12 years but were comparable on day 14. The mean AUC0-24-based accumulation factors of itraconazole and hydroxyitraconazole from day 1 to 14 ranged from 3.3 to 8.6 and 2.3 to 11.4, respectively. After 14 days of treatment, Cmax, AUC0-24, and the half-life, respectively, were (mean +/- standard deviation) 571+/-416 ng/ml, 6,930+/-5,830 ng.h/ml, and 47+/-55 h in the children aged 6 months to 2 years; 534+/-431 ng/ml, 7,330+/-5,420 ng.h/ml, and 30.6+/-25.3 h in the children aged 2 to 5 years; and 631+/-358 ng/ml, 8,770+/-5,050 ng.h/ml, and 28.3+/-9.6 h in the children aged 5 to 12 years. There was a tendency to have more frequent low minimum concentrations of the drugs in plasma for both itraconazole and hydroxyitraconazole for the children aged 6 months to 2 years. The oral bioavailability of the solubilizer hydroxypropyl-beta-cyclodextrin was less than 1% in the majority of the patients. In conclusion, an itraconazole oral solution given at 5 mg/kg/day provides potentially therapeutic concentrations in plasma, which are, however, substantially lower than those attained in adult cancer patients, and is well tolerated and safe in infants and children.

Clinical pharmacokinetics of Neoral in pediatric recipients of primary liver transplants

Pediatric liver transplant recipients constitute a population characterized by a particularly unpredictable and poor bioavailability of cyclosporin (CyA). Even though several adult studies show that the new oral formulation of CyA, Neoral (NEO), produces better bioavailability and blood level predictability, few data describe its pharmacokinetics in children. We performed a complete analysis of the pharmacokinetics of NEO in ten small children after primary liver transplantation. Three pharmacokinetic profiles were set up with data obtained from tests taken during i.v. administration of CyA, after the first oral NEO dose, and after the last NEO dose before discharge from the hospital. The mean half-lives obtained were 8.1, 7.7, and 6.9 h, respectively, and the bioavailabilities were 22% and 21% for the first and last NEO doses. A large interpatient variability was observed. This was due, in part, to episodes of diarrhea that interfered with the pharmacokinetic evaluation and, in part, to the variability of post-transplant hepatic function. There was a good correlation between CyA trough levels and their related AUCs for both NEO profiles (r = 0.93 and r = 0.74, respectively). We conclude that, even though the pediatric OLT population remains more unpredictable than that of adults, NEO has a relatively rapid half-life and a remarkably improved bioavailability.

Early signs and risk factors for the increased incidence of Epstein-Barr virus-related posttransplant lymphoproliferative diseases in pediatric liver transplant recipients treated with tacrolimus

BACKGROUND

Posttransplant lymphoproliferative disease (PTLD) is a life-threatening condition the incidence of which in pediatric solid organ transplantation may be related to the immunosuppressive load. It has been suggested that tacrolimus, a new and potent immunosuppressor, causes an increased incidence of this syndrome.

METHODS

The incidence, early signs, and risk factors for lymphoproliferative disease were reviewed in a cohort of 89 pediatric liver transplant recipients treated with tacrolimus.

RESULTS

Eighteen patients (20%) developed a PTLD-16 concomitant to a primary Epstein-Barr virus (EBV) infection and 2 with previous immunity against EBV. Three additional patients had preliminary signs of PTLD concomitant to primary EBV infection, but did not develop individualized lymphoid masses. Six patients died (6.7% of all tacrolimus-treated patients). Mean tacrolimus blood level during the 3 months preceding EBV infection reached 11.8+/-1.8 ng/ml in PTLD patients versus 9.4+/-3.4 ng/ml in non-PTLD patients (0.05<P<0.1). Previous OKT3 or antithymocyte globulin treatment was also significantly associated to PTLD. There was no association with age, rejection episodes, steroid-resistant rejection, prior cytomegalovirus infection, HLA mismatch, living donor or cadaveric organ transplantation, United Network for Organ Sharing status at the time of orthotopic liver transplant, and primary or rescue tacrolimus treatment. A significant increase of total gamma-globulin level occurred in PTLD patients, and mono/oligoclonal production was significantly associated to PTLD.

CONCLUSION

In EBV-infected pediatric liver transplant recipients, use of OKT3 or antithymocyte globulin and high tacrolimus blood levels are risk factors for a significant increase in the incidence of PTLD. An increase in total gamma-globulin level and appearance of mono/oligoclonal immunoglobulin production are the major preliminary signs of the syndrome.

Expression of insulin receptors and of 60-kDa receptor substrate in rat mature and immature enterocytes

The mechanism(s) by which rat immature enterocytes exhibit increased responsiveness to insulin before weaning is unknown. Therefore, we have analyzed the distribution, ontogeny, and molecular properties of insulin receptors (IR) and of related substrates in immature and mature enterocytes. IR were studied by radioligand binding assays, cross-linking labeling, immunohistochemistry, and in vitro phosphorylated substrates by immunoprecipitation. Regardless of age, 125I-insulin binding to IR was five times higher in crypt cells than in villus cells and two times higher in the ileum than in the jejunum. Binding capacity to villus cells from sucklings (day 14) exceeded three times that of older animals (day 30 and day 60). Scatchard analysis of equilibrium binding data confirmed an age-related decrease in low- and high-affinity receptor classes without change in affinity constants. In concordance, both alpha- and beta-IR subunits were more abundant in immature than in mature membranes. In vitro, insulin elicited the phosphorylation of three membrane proteins (96, 60 and 42 kDa), whose signals were virtually inhibited by preincubating membranes with antireceptor monoclonal antibodies. By immunoprecipitation, the 60-kDa signal was rapidly detected as a tyrosine-phosphorylated protein, expressed in mature and immature membranes, and identified as a receptor substrate phosphorylated in vitro by the IR tyrosine kinase. In conclusion, 1) increased responsiveness of rat immature enterocytes to insulin could be related to high membrane concentrations of IR and 2) normal rat enterocytes express a 60-kDa phosphotyrosine protein identified as a direct substrate of the IR tyrosine kinase.

Ursodeoxycholic acid therapy in pediatric patients with progressive familial intrahepatic cholestasis

Progressive familial intrahepatic cholestasis (PFIC) is a lethal inherited childhood cholestasis of hepatocellular origin. Different subtypes of PFIC have been described according to serum gamma-glutamyl transpeptidase (GGT) activity. There is currently no effective medical therapy available for children with PFIC. We report on 39 patients with PFIC who received ursodeoxycholic acid (UDCA) orally (20-30 mg/kg b.w./day) for a period of 2 to 4 years. Group 1 (n = 26) consisted of children with normal GGT activity, and group 2 (n = 13) of children with high GGT activity. Within group 1, liver tests normalized in 11 children, improved in 5, and stabilized or worsened in 10. Within group 2, liver tests normalized in six children, improved in four, and stabilized or worsened in three. Improvement of parameters was associated with an enrichment of the circulating pool of bile acids with UDCA. Hepatosplenomegaly and pruritus disappeared or diminished in children in whom liver tests normalized. In nine of these children, liver tests worsened and normalized again after stopping and restarting UDCA. Liver histology assessed in four children after normalization of liver tests and 2 years of treatment showed a decrease in fibrosis. We conclude that UDCA should be considered in the initial therapeutic management of children with PFIC, because it appears effective in resolving or improving the liver function and the clinical status of a fair proportion of children. Chronic UDCA therapy might thus avoid the need for liver transplantation in some children with PFIC.

Intestinal transport of calcium in rat biliary cirrhosis

The characteristics of intestinal calcium transport in chronic cholestasis remain largely unknown. Using an experimental model of biliary cirrhosis in the rat, we aimed to investigate changes in calcium transport at the jejunal and ileal levels. Two methods were used: 1) uptake of 45Ca in brush border membrane vesicles and 2) measurements of transepithelial fluxes of calcium in Ussing chambers. Thirty days postsurgery, cholestatic rats presented biliary cirrhosis, with normal growth, normal daily energy, and calcium intakes, but had depressed circulating levels of 25-(OH)-vitamin D2 and 1,25-(OH)-vitamin D3. Compared with sham-operated controls, 45Ca uptake ([Ca2+] = 0.03 mmol) measured in vesicles from cholestatic rats was decreased by 3-fold in the duodenojejunum, in concordance with a lower content in brush border membrane calmodulin. Other changes in brush border membrane composition included decreases in structural proteins, microvillous enzymes, and in triglyceride content. Transepithelial fluxes of calcium measured in the ileum ([Ca2+] = 1.2 mmol) revealed in controls a net basal secretion flux (Jnet = -30.4 +/- 8.1 mmol.h-1.cm-2) that was reduced by 3-fold (p < 0.05) in vitamin D-deficient rats (Jnet = -10.4 +/- 4.8 mmol.h-1.cm-2). In response to 25-(OH)-vitamin D2 treatment, calcium uptake rates increased by 40% in the jejunum, whereas in the ileum, the secretion flux returned to basal control levels. Oral administration of taurocholate or tauroursodeoxycholate (50 mmol) depressed almost completely calcium uptake capacity in the duodenojejunum. By complexing free calcium, tauroconjugated bile acids inhibited in vitro calcium uptake proportionally to their concentration in the medium (0-40 mmol). Our data indicate that, in rat biliary cirrhosis, transport capacity of calcium in the duodenojejunum is markedly reduced in association with vitamin D deficiency and alterations in brush border membrane composition.

Branched chain amino acids improve body composition and nitrogen balance in a rat model of extra hepatic biliary atresia

Malnutrition and growth retardation remain a major complication in infants with extrahepatic biliary atresia associated cholestasis. The purpose of this study was to investigate whether oral supplementation with branched chain amino acids (BCAA) can correct malnutrition in a rat model of biliary atresia. Four groups of 15 rats, 30 d old, were used. Group A were shamoperated animals, given a normal laboratory diet (17.5% of caloric intake as proteins). Group B were cholestatic rats (biliary atresia) fed a diet enriched in BCAA (supplement of 8.5%, valine/leucine/isoleucine ratio 1:1:1). Group C were cholestatic mice fed a diet enriched in casein (supplement of 8.5%). Group D were cholestatic mice fed a normal diet. Thirty-two days after surgery, groups were compared for body weight, serum amino acid content, nitrogen balance, muscle mass, and carcass composition. The results showed that the weight of group B, C, and D animals was 85, 81, and 64% of group A (controls). Serum BCAA levels were markedly increased in group B animals. Nitrogen retention was similar in groups B and A, but reduced to 63 and 44% in groups C and D, respectively. Dry weights were similar in group A (39.1% of body weight) and B (37.7%), but reduced to 28.1 and 28.6% of body weight in groups C and D. Body proteins were higher in groups A (13.9%) and B (14.2%) than in group D (9.7%) rats. Mineral content of group B animals was 84% of those of group A, 50% in group C, and 23% in group D rats. It was concluded that an oral supplement of BCAA can correct growth, nitrogen retention, and body composition in experimental biliary atresia. Administration of BCAA supplements to cholestatic infants should be considered.

Recurrence of neonatal haemochromatosis in half sibs born of unaffected mothers

We report two families in which neonatal haemochromatosis was observed in half sibs. In the first family, two successive girls were born of different fathers. In the second family, an affected brother and sister were followed by an affected half brother born after donor insemination. These observations, as well as a previous abstract describing two affected half sisters, revive the debate over the inheritance of neonatal haemochromatosis. Incomplete penetrance or gonadal mosaicism for a dominant disorder, a maternal "environmental factor", or mitochondrial defect may be more suitable explanations than autosomal recessive inheritance in this condition. Alternative modes of fertilisation, such as donor insemination or in vitro fertilisation with donor eggs, should be considered with caution.