Frederick M. Karrer

THE FREQUENCY OF EPSTEIN-BARR VIRUS INFECTION AND ASSOCIATED LYMPHOPROLIFERATIVE SYNDROME AFTER TRANSPLANTATION AND ITS MANIFESTATIONS IN CHILDREN

Twenty cases of Epstein-Barr virus (EBV)-associated lymphoproliferative syndrome (LPS), defined by the presence of EBV nuclear antigen and/or EBV DNA in tissues, were diagnosed in 1467 transplant recipients in Pittsburgh from 1981–1985. The frequency of occurrence in pediatric transplant recipients was 4% (10/253), while in adults it was 0.8% (10/1214) (P < .0005). The frequency of LPS in adults declined after 1983 coincidental with the introduction of cyclosporine monitoring. However there was no apparent decline of LPS in children. We describe these ten pediatric cases and one additional case of LPS in a child who received her transplant before 1981. The frequency of EBV infection in 92 pediatric liver recipients was 63%. Of these subjects, 49% were seronegative and 77% of those acquired primary infection. Of 11 cases of pediatric EBV-associated LPS, 10 were in children who had primary infection shortly before or after transplantation. These results reinforce the importance of primary EBV infection in producing LPS, which was previously shown in adults. Children are at greater risk because they are more likely to be seronegative for EBV and to acquire primary infection. Three clinical types of LPS were recognized in children. The first (5 cases) was a self-limited mononucleo-sislike syndrome. The second syndrome (4 cases) began similarly, but then progressed over the next two months to widespread lymphoproliferation in internal organs and death. The third type (2 cases) was an extranodal intestinal monoclonal B cell lymphoma, occurring late after primary infection.

Adult living donor liver transplantation using a right hepatic lobe

BACKGROUND Living donor liver transplantation has gained wide acceptance as an alternative for children with end-stage liver disease. The standard left lateral segment used in this operation does not provide adequate parenchymal mass to broaden its application to larger children or adults. METHODS We report two cases of adult to adult living donor liver transplantation using a right hepatic lobe in patients with chronic liver disease. RESULTS Both recipients experienced excellent initial graft function and have normal liver function 4 and 9 months postoperatively. Both donors are alive and well and returned to normal life 4 weeks postoperatively. CONCLUSIONS Our initial experience suggests that this technique is a safe and reliable option for adults with chronic end-stage liver disease. A conservative application of this procedure in the adult population could significantly reduce the mortality on the adult waiting list.

Pathogenesis and outcome of biliary atresia : current concepts

Neonatal cholestatic disorders are a group of hepatobiliary diseases occurring within the first 3 months of life. Bile flow is impaired, and patients have conjugated hyperbilirubinemia, acholic stools, and hepatomegaly. Overall, 1 in 2,500 live births is affected with a neonatal cholestatic disorder (1). The two most common causes of neonatal cholestasis are biliary atresia and idiopathic neonatal hepatitis, accounting for up to 50% to 70% of cases. Other causes include a variety of neonatal infections (viral, toxoplasmosis, syphilis, bacterial), metabolic and genetic diseases, progressive familial intrahepatic cholestatic disorders (PFIC), paucity of interlobular bile duct disorders (e.g., Alagille syndrome), choledochal cyst, ischemia–reperfusion injury, association with parenteral nutrition administration, and other conditions (Table 1). Despite clinical improvement after the portoenterostomy procedure, approximately 70% to 80% of children with biliary atresia will eventually require liver transplantation; thus, biliary atresia alone accounts for almost 50% of all liver transplants performed in children (1). It should be noted that

Oxidant injury to hepatic mitochondria in patients with Wilson's disease and Bedlington terriers with copper toxicosis

77 million is spent each year in the United States on liver transplantation for children and the ensuing hospitalizations (2). This sum of money covers 0.2% of total health care expenditures related to children, even though these children represent 0.0006% of the total pediatric population. Importantly, this disproportionate expenditure for liver transplantation in children could be cut in half if improved therapies for biliary atresia were developed that could abrogate or further delay the need for liver transplantation. Remarkably, little is known about the etiopathogenesis of biliary atresia; consequently, there has been slow progress in developing improved therapies or preventative strategies during the past decade. The purpose of this review is to summarize recent advances in the diagnosis and management of biliary atresia, examine the clinical outcome, describe the evolving theories of the etiology and pathogenesis of this disorder, and highlight gaps in our current knowledge.

The positive predictive value of rib fractures as an indicator of nonaccidental trauma in children

BACKGROUND/AIMS Copper overload leads to liver injury in humans with Wilsons disease and in Bedlington terriers with copper toxicosis; however, the mechanisms of liver injury are poorly understood. This study was undertaken to determine if oxidant (free radical) damage to hepatic mitochondria is involved in naturally occurring copper toxicosis. METHODS Fresh liver samples were obtained at the time of liver transplantation from 3 patients with Wilsons disease, 8 with cholestatic liver disease, and 5 with noncholestatic liver disease and from 8 control livers. Fresh liver was also obtained by open liver biopsy from 4 copper-overloaded and 4 normal Bedlington terriers and from 8 control dogs. Hepatic mitochondria and microsomes (humans only) were isolated, and lipid peroxidation was measured by lipid-conjugated dienes and thiobarbituric acid-reacting substances. In humans, liver alpha-tocopherol content was measured. RESULTS Lipid peroxidation and copper content were significantly increased (P < 0.05) in mitochondria from patients with Wilsons disease and copper-overloaded Bedlington terriers. More modest increases in lipid peroxidation were present in microsomes from patients with Wilsons disease. Mitochondrial copper concentrations correlated strongly with the severity of mitochondrial lipid peroxidation. Hepatic alpha-tocopherol content was decreased significantly in Wilsons disease liver. CONCLUSIONS These data suggest that the hepatic mitochondrion is an important target in hepatic copper toxicity and that oxidant damage to the liver may be involved in the pathogenesis of copper-induced injury.

Studies of Pediatric Liver Transplantation (SPLIT) : Year 2000 outcomes

BACKGROUND Rib fractures have a strong association with nonaccidental trauma (NAT) and severe trauma. The purposes of this study were to evaluate rib fractures in children to determine (1) the positive predictive value of a rib fracture in defining NAT and (2) the frequency of rib fractures as the only skeletal manifestation of NAT. METHODS We reviewed the medical records and imaging of all children with rib fractures over a 6-year period. NAT was determined by the Child Advocacy and Protection team. RESULTS In children younger than 3 years of age, the positive predictive value (PPV) of a rib fracture as an indicator of NAT was 95%. The positive predictive value increased to 100% once historical and clinical circumstance excluded all other causes for rib fractures. CONCLUSION In this study, rib fracture(s) were the only skeletal manifestation of NAT in 29% of the children.

Biliary Atresia Is Associated with CD4 + Th1 Cell–Mediated Portal Tract Inflammation

Background. Initiated in 1995, the Studies of Pediatric Liver Transplantation (SPLIT) registry database is a cooperative research network of pediatric transplantation centers in the United States and Canada. The primary objectives are to characterize and follow trends in transplant indications, transplantation techniques, and outcomes (e.g., patient/graft survival, rejection, growth parameters, and immunosuppressive therapy.) Methods. As of June 15, 2000, 29 centers registered 1144 patients, 640 of whom received their first liver-only transplant while registered in SPLIT. Patients are followed every 6 months for 2 years and yearly thereafter. Data are submitted to a central coordinating center. Results. One/two-year patient survival and graft loss estimates are 0.85/0.82 and 0.77/0.72, respectively. Risk factors for death include: in ICU at transplant (relative risk (RR)=2.63, P <0.05) and height/weight deficits of two or more standard deviations (RR=1.67, P <0.05). Risk factors for graft loss include: in ICU at transplant (RR=1.77, P <0.05) and receiving a cadaveric split organ compared with a whole organ (RR=2.3, P <0.05). The percentage of patients diagnosed with hepatic a. and portal v. thrombosis were 9.7% and 7%, respectively; 15% had biliary complications within 30 days. At least one re-operation was required in 45%. One/two-year rejection probability estimates are 0.60/0.66. Tacrolimus, as primary therapy posttransplant, reduces first rejection risk (RR=0.70, P <0.05). Eighty-nine percent of school-aged children are in school full-time, 18 months posttransplant. Conclusions. This report provides one of the first descriptions of characteristics and clinical courses of a multicenter pediatric transplant population. Observations are subject to patient selection biases but are useful for generating hypothesis for future studies.

Prednisone withdrawal 14 days after liver transplantation with mycophenolate: a prospective trial of cyclosporine and tacrolimus.

A proposed mechanism in the pathogenesis of biliary atresia involves an initial virus-induced, progressive T cell–mediated inflammatory obliteration of bile ducts. The aim of this study was to characterize the inflammatory environment present within the liver of infants with biliary atresia to gain insight into the role of a primary immune-mediated process versus a nonspecific secondary response to biliary obstruction. Frozen liver tissue obtained from patients with biliary atresia, neonatal giant cell hepatitis, total parenteral nutrition (TPN)–related cholestasis, choledochal cysts, and normal control subjects was used for fluorescent immunohistochemistry studies of cellular infiltrates, cytokine mRNA expression, and in situ hybridization for localization of cytokine-producing cells. Immunohistochemistry revealed increases in CD8+ and CD4+ T cells and Kupffer cells (CD68+) in the portal tracts of biliary atresia. Reverse transcription–PCR analysis of biliary atresia tissue showed a Th1-type cytokine profile with expression of IL-2, interferon-γ, tumor necrosis factor-α, and IL-12. This profile was not seen in normal, neonatal hepatitis or choledochal cyst livers but was present in TPN-related cholestasis. In situ hybridization revealed that the Th1 cytokine–producing cells were located in the portal tracts in biliary atresia and in the parenchyma of TPN-related cholestasis. A distinctive portal tract inflammatory environment is present in biliary atresia, involving CD4+ Th1 cell–mediated immunity. The absence of similar inflammation in other pediatric cholestatic conditions suggests that the portal tract inflammation in biliary atresia is not a secondary response to cholestasis but rather indicates a specific immune response involved in the pathogenesis of biliary atresia.

Improvement of cyclosporin absorption in children after liver transplantation by means of water-soluble vitamin E

BACKGROUND The long-term complications of immunosuppressive therapy such as diabetes, hypercholesterolemia, and hypertension are a major source of morbidity in liver transplant recipients. In this prospective, randomized, open-label study we completely withdrew prednisone (PRED) 14 days after liver transplantation in an effort to decrease these metabolic complications. Patients were maintained on mycophenolate mofetil (MMF) in combination with either cyclosporine (CsA; Neoral formulation) or tacrolimus (TAC). Thus, we also were able to compare CsA to TAC in patients not receiving PRED with respect to efficacy, toxicity, and effect on posttransplant metabolic complications. METHODS A total of 71 patients were randomized to receive either TAC-MMF (n=35) or CsA-MMF (n=36) after liver transplantation and were analyzed for patient and graft survival. Fifty-eight patients continued the immunosuppressive protocol for at least 6 months after transplantation and were analyzed for the incidence of acute rejection and the prevalence of diabetes, hypertension, and hypercholesterolemia. RESULTS The 6-month patient survival rates were 94.4% for CsA-MMF and 88.6% for TAC-MMF. Corresponding 6-month graft survival rates were 88.7% and 85.71% with no immunologic graft losses in either group. The incidence of biopsy-proven acute rejection was 46% for CsA-MMF and 42.3% for TAC-MMF. Six patients were converted from CsA to TAC (four for recurrent rejection) and seven patients were converted from TAC to CsA (four for neurotoxicity). Only one patient (in the TAC-MMF group) developed new-onset posttransplant diabetes. In contrast, four of eight patients in the CsA-MMF group who were diabetic before transplant became nondiabetic in the first 3 months after transplant. The mean serum cholesterol level was significantly lower in the TAC-MMF group than in the CsA-MMF group (145.2+/-41.8 mg/dl and 190.3+/-62.2, respectively; P<0.001) and the incidence of hypertension was lower in the TAC-MMF group (12% vs. 30.3% in the CsA-MMF group, P<0.01). Both groups had a lower incidence of metabolic complications compared with a historical group (n=100) maintained on CsA and PRED (10 mg/day at 6 months). CONCLUSIONS MMF in combination with either TAC or CsA allows withdrawal of PRED 14 days after liver transplantation with a moderate rejection rate and no immunologic graft losses. Early PRED withdrawal decreases posttransplant diabetes, hypercholesterolemia, and hypertension, but patients maintained on TAC have lower serum cholesterol levels and a lower incidence of hypertension than CsA-treated patients.

Anorectal malformations: Evaluation of associated spinal dysraphic syndromes*

Many childhood recipients of liver transplantation require massive doses of cyclosporin to achieve therapeutic blood concentrations of the drug. The impaired absorption of this strongly lipophilic drug may be due to reduced intestinal absorptive area, suboptimal mixing of the drug with hepatobiliary secretions, or residual cholestasis. Improvement of cyclosporin absorption was sought by means of oral coadministration of d-alpha-tocopheryl-polyethylene-glycol-1000 succinate (TPGS), a water-soluble form of vitamin E which can form micelles. 25 mg/kg daily of TPGS was given to six paediatric liver transplant recipients and one young adult with severe hepatobiliary graft-vs-host disease after bone-marrow transplantation, who required 29-136 mg/kg cyclosporin daily to achieve therapeutic cyclosporin blood concentrations. Five responded; the oral cyclosporin dose could be reduced by 40-72% within 2 months. In addition, intravenous cyclosporin was stopped in two of the responders. In the two non-responders the cyclosporin doses at entry were similar to those in the responders after TPGS treatment. Oral cyclosporin absorption tests correctly predicted the outcome of treatment in three responders and one non-responder tested. Treatment with TPGS to enhance cyclosporin absorption might be a useful way of reducing the high cost of immunosuppression in paediatric liver transplant recipients.