Markers of operational immune tolerance after pediatric liver transplantation in patients under immunosuppression

A prospective identification of the estimated 20-50% of pediatric LTX recipients developing operational tolerance would be of great clinical advantage. So far markers of immune tolerance - T-cell subpopulations or gene expression profiles - have been investigated only retrospectively in successfully weaned patients. Fifty children aged 8-265 months (median 89) were investigated 1-180 months (median 44) after LTX under ongoing immunosuppression. T-cell subpopulations were measured during regular post-transplant visits using FACS (Vδ1- vs. Vδ2-γδ-T cells and Tregs). A Vδ1/Vδ2-γδ-T-cell ratio ≥1.42 previously reported in operational tolerance was found in 12 of 50 (24%) patients. In analogy, a Treg count ≥44 per μL was found in 35 of 50 (70%) patients and a Treg proportion ≥2.23% of CD3(+) -T cells in 39 of 50 (78%) patients. Only 9 of 50 patients (18%) fulfilled both criteria. The parameters Vδ1/Vδ2-γδ-T-cell ratio and Tregs were not significantly correlated to each other or with donor type or immunosuppression. Vδ1/Vδ2-γδ-T-cell ratio was more stable in serial examinations compared with Treg analyses. The observed proportion of 18% pediatric LTX patients with potential operational tolerance is in accordance with previous reports. However, clinical experience shows that rejections may happen even after long-time weaning of immunosuppression. This suggests that operational tolerance is a dynamic process, with uncertain prediction by Vδ1/Vδ2-γδ-T-cell ratio and/or Tregs under immunosuppression.

Cognitive abilities, behaviour and quality of life in children after liver transplantation

AIMS

We investigated interrelations between cognitive abilities, behavioural problems, quality of life and disease-related variables of children after LTX.

METHODS

Our sample consisted of 25 children. They were 8.5/2.8 (M/SD) years old and had received the transplant 5.5/3.1 years previously. For assessment we used well-established instruments.

RESULTS

Liver transplanted children scored below the population mean on the cognitive as well as on the behavioural instrument and showed scores below average in the scales Self-esteem, Friends and Total Score regarding QoL. Behavioural problems were associated with poorer cognitive performance (r=-0.38 to -0.63). QoL regarding physical well-being was correlated with sequential processing (r=0.41). Lower sequential processing scores were associated with lower QoL. Also between behavioural parameters and QoL correlations could be determined. Children with more behavioural problems experienced lower QoL (r=-0.40 to r=-0.76). Age at onset of disease showed correlations with behavioural and QoL parameters (r=-0.49 resp. r=0.44). Cognitive functioning was associated with medical complications (r=-0.44).

CONCLUSIONS

High interrelations between cognitive functioning, behavioural deficits and QoL were obtained. Especially noticeable are correlations between sequential processing and internalized behavioural functions as both are associated with left lateralized brain functioning. This relationship could indicate differential effects on brain development during the preoperative phase.

Effectiveness of Rex shunt in children with portal hypertension following liver transplantation or with primary portal hypertension

Portal vein thrombosis can occur as a result of primary anomalies, after liver transplantation, and for other reasons. It may result in severe complications secondary to portal hypertension, such as bleeding from esophageal or gastric varices, hypersplenism, or impaired somatic growth. In this retrospective study, we analyzed the outcome of 25 children who underwent a Rex shunt procedure. The following venous grafts were used as the shunt: the autologous internal or external jugular vein (n = 17) or a cryopreserved graft (n = 5); in three patients the umbilical vein was recanalized. The median follow up time was 109 months (range 18 days-146 months). The best results were achieved in patients in whom an autologous jugular vein segment was used as a vascular graft for the Rex shunt (shunt patency of 88%). In patients with a functioning shunt no further lower or upper gastrointestinal bleeding occurred. And in the entire study population hypersplenism syndrome improved after surgery. In our large cohort of pediatric patients, the Rex shunt has shown to be an effective method to eliminate portal hypertension and to revascularize the liver and thereby prevents the possible consequences of long-term portosystemic shunting.

Hepatoblastoma in a child with progressive familial intrahepatic cholestasis

End-stage liver cirrhosis because of metabolic or infectious diseases predisposes to hepatic malignancies like hepatocellular carcinoma. We report the first case of hepatoblastoma incidentally detected in the explanted liver of a 2-yr-old child undergoing liver transplantation for cirrhosis because of progressive familial intrahepatic cholestasis (PFIC). The diagnosis was difficult to obtain. The hepatoblastoma was not seen on ultrasound examination of the cirrhotic liver. As we could confirm retrospectively, alpha fetoprotein (AFP) was found elevated prior to transplantation. Two years after successful transplantation, there are no signs of malignancy detectable by clinical and radiological methods. We conclude from this case that PFIC may induce hepatoblastoma and that children with liver cirrhosis should undergo routine screening of serum AFP concentration.

Hypogammaglobulinemia in pediatric liver transplant recipients

Hypogammaglobulinemia has been reported after solid organ transplantation in adults, however immunoglobulin replacement [intravenous immunoglobulins (IVIG)] is only necessary in a minority of affected patients. We here present three pediatric patients with severe post-transplant hypogammaglobulinemia following liver transplantation (LTx) receiving a cyclosporine-based standard immunosuppression. Patient 1 was transplanted at the age of 10 months for biliary atresia. Eight weeks post-Ltx the serum IgG was 1.7 g/L. Patient 2 was transplanted at the age of 12 yr for acute liver failure. Four weeks post-Ltx the IgG dropped to 2.6 g/L. Patient 3 was transplanted at the age of 4 months for biliary atresia. Ten weeks post-Ltx severe hypogammaglobulinemia (IgG < 1.48 g/L) was diagnosed during a severe infectious complication. Patients 1 and 3 received a steroid bolus therapy for acute graft rejection. All patients had normal IgG concentrations prior to Ltx and lymphocyte subsets were post-operatively in the normal range. There was no extensive loss of protein by ascites. IGIV were replaced in the three patients monthly without further complications. In two of the patients (1 and 3) IVIG therapy was discontinued 8 and 10 months after Ltx when the immunosuppression has been reduced and serum IgG concentrations were found in the normal range without further immunoglobulin replacement. Severe hypogammaglobulinemia is a rare phenomenon following pediatric LTx and seems to be mainly caused by immunosuppressive drugs, however, the exact underlying mechanisms are unclear. A screening for hypogammaglobulinemia is useful after pediatric LTx, especially in patients with an intensified immunosuppression. Moreover, further immunologic research in affected patients is necessary.

Split liver transplantation: past, present and future

The technique of liver splitting offers an effective way of increasing the donor pool and decreasing pediatric waiting list mortality. A donor liver is divided in such a way that the left lateral liver graft can be transplanted into a small child and the right extended liver graft into an adult. This innovative technique did not harm the adult recipient pool. Because of its technical complexity and the initial poor results after split liver transplantation (SLT) this procedure has slowly gained acceptance in the Transplantation Community after its first introduction in 1988 (4). Small children with end stage liver disease suffered the most from the extreme shortage of cadaveric donor organs due to the difficulty of finding size-matched donors. The successful surgical development of SLT and a better donor and recipient selection have led to a reduction of the pediatric pretransplant mortality to nearly zero and to results comparable with those after whole organ transplantation (WLT). By splitting a donor organ into two 'full' hemi-grafts and providing a small adult ( < 60 kg) or a big child ( > 30 kg) with the full left graft and a medium-sized adult (60-80 kg) with the full right graft, a small-for-size situation for adolescents or adults can be avoided and the total number of available grafts can be increased. It is the goal to provide each recipient with its customized graft in the near future. However, splitting for two adults requires high technical skills and profound knowledge of the anatomic variations and should be performed in centers with large transplantation experience.

C2 blood concentrations of orally administered cyclosporine in pediatric liver graft recipients with a body weight below 10 kg

Pharmacokinetic studies in adult and pediatric liver transplant recipients have shown that the C(2) monitoring is superior to the traditional determination of CsA trough levels (C(0)) as an estimate of CsA exposure. However, target reference values for C(2) in very small infants have not been established yet. The objective of our study was to assess the distribution of C(2) levels in the first week following Ltx and to analyze enteral absorption of CsA for this group of patients. We documented CsA C(0) and C(2) levels in 25 infants with a body weight below 10 kg (median 6.8 kg; range 3.0-9.8 kg) in the first 7 days after Ltx. The infants had a median age at transplantation of 7 months (range 0.3-20.0 months). The underlying diagnoses were biliary atresia (n = 17), acute liver failure (n = 4), metabolic disease (n = 4). All children received CsA microemulsion (Neoral, initial 10 mg/kg/day), prednisolone, and two single doses of basiliximab as immunosuppressive drugs. The mean C(0) and C(2) levels were as follows: day 1: C(0) 77.0 +/- 39.6, C(2) 340.5 +/- 140.0 ng/mL; day 2: C(0) 135.5 +/- 53.2, C(2) 467.0 +/- 168.2 ng/mL; day 3: C(0) 146.5 +/- 70.8, C(2) 519.0 +/- 219.1 ng/mL; day 4: C(0) 168.5 +/- 55.1, C(2) 570.0 +/- 163.7 ng/mL; day 5: C(0) 156.5 +/- 38.0, C(2) 612.0 +/- 132.4 ng/mL; day 6: C(0) 177.0 +/- 41.1, C(2) 606.0 +/- 149.2 ng/mL; day 7: C(0) 174.0 +/- 27.2, C(2) 622.0 +/- 98.8 ng/mL (r = 0.82, p < 0.05). This analysis demonstrates that there is a good enteral absorption of CsA in very small children post-Ltx in the early post-operative period. Based on the C(2) levels achieved, we conclude that there is a good correlation between C(0) and C(2) levels even in very small infants.

Basiliximab monotherapy following B-cell lymphoma after pediatric liver transplantation and anti-CD20 therapy

The chimeric, monoclonal antibody basiliximab inhibits the proliferation and clonal expansion of activated T cells. To date basiliximab has been used only in combination with other immunosuppressive agents for rejection prophylaxis after solid organ transplantation. An infant underwent liver transplantion (LTx) at the age of 5 months because of biliary atresia. The primary immunosuppression consisted of cyclosporine and prednisolone. As a result of a steroid resistant rejection episode on day 26 post-LTx we had to switch the initial immunosuppressive regiment to tacrolimus and steroids. Because of severe cholestasis and assumed impaired enteral resorption we were forced to administer an unusually high dosage (2 mg/kg/day) of tacrolimus. Four months after LTx an intestinal B-cell lymphoma was diagnosed when the patient suffered from a small bowel perforation. After stopping the immunosuppressive medication we started treatment with the anti-CD20 monoclonal antibody rituximab for B-cell depletion. During the 12 wk no B cells were detectable in the peripheral blood by flow cytometry. In this setting we started a monotherapy with repetitive doses of basiliximab for immunosuppression. During the following course there was no further rejection and no recurrence of the tumor. From this experience we conclude that monotherapy with basiliximab after LTx and anti-CD20 treatment for B-cell lymphoma is efficient and safe.

The oxidative metabolism of polymorphonuclear neutrophils in pediatric liver graft recipients

BACKGROUND

Data on the oxidative metabolism of polymorphonuclear neutrophils (PMN) after solid organ transplantation are very limited. We hypothesized that immunosuppressive agents reduce the capacity of PMN to produce reactive oxygen species, such as O2(-), H2O2, OH, and OCL(-) leading to an increased susceptibility to infectious complications after liver transplantation.

METHODS

A lucigenin-enhanced chemiluminescence (CL) assay was used with soluble and particulate stimuli to study the oxidative metabolism of PMN in pediatric liver graft recipients. Sixteen patients (median age: 2.4 yr) were enrolled in a prospective study and integrated CL response was compared with the CL activity of 29 healthy controls.

RESULTS

In the second week post-transplant, we found a significantly reduced CL activity. Pre-operatively, and after lowering steroids and cyclosporin A (CsA) the oxidative burst was normal.

CONCLUSIONS

Our data suggest that CsA and steroids may not only influence T and B cells but also PMN, which may be a relevant factor for the incidence of infectious complications in pediatric liver graft recipients.

[Living organ donation vs. cadaveric donation - study of liver transplanted children and their families]

There is only scarce information on the quality of life of child recipients of liver transplants and their families. Particularly children with a living related graft and their families never have been compared to children who received a cadaveric graft and their families. We investigated the following issues in our study: How do parents and children from participating families rate their strain, their quality of life and their relationships within their family? Do families with a living - related donor differ from those with a cadaveric donor? What do living donors and their partners think about the donation retrospectively? The study was conducted with 106 participants from 50 families (42 mothers, 40 fathers, and 24 children older than 6 years). In 20 of these families, a living transplantation had been performed. Participants were interviewed and asked to fill out several questionnaires. School-aged children with a liver transplant show good social integration among their peers and in school. The child's disease, however, has a great impact on the family. Family members show a reduction in social contact, and an increase in marital crises, and problematic relations amongst siblings. Families in which a cadaveric graft was performed, are less satisfied with life, and show more symptoms of exhaustion. Every family studied possessed or acquired - a high degree of internal or external coping resources. Living - related donors tried hard to obtain an understanding of the medical context. The partner, rather than the donor himself, feels anxious before the donation. The limited time available for the decision to donate is not perceived by the donors to be critical. Ten percent of living donors feel "a little" that their health is affected. The decision to donate is supported "strongly" or "very strongly" by the partners in 80 % of the cases. A possible strain on the child through the expectation of gratitude by the donor is stated by 20 %. All of the donors agree that if they were to be asked today, they would donate again, only one of the partners raised objections. In summary, as a retrospective pilot study, this study primarily generates hypotheses rather than testing them and helps to develop research tools for the field. Results suggest that a psychological support be made available both prior to and following the operation, not only for the children but also for their families, with particular attention to the partners of the living donors and the siblings of the affected children.

Is there still a need for living-related liver transplantation in children?

OBJECTIVE

To assess and compare the value of split-liver transplantation (SLT) and living-related liver transplantation (LRT).

SUMMARY BACKGROUND DATA

The concept of SLT results from the development of reduced-size transplantation. A further development of SLT, the in situ split technique, is derived from LRT, which itself marks the optimized outcome in terms of postoperative graft function and survival. The combination of SLT and LRT has abolished deaths on the waiting list, thus raising the question whether living donor liver transplantation is still necessary.

METHODS

Outcomes and postoperative liver function of 43 primary LRT patients were compared with those of 49 primary SLT patients (14 ex situ, 35 in situ) with known graft weight performed between April 1996 and December 2000. Survival rates were analyzed using the Kaplan-Meier method.

RESULTS

After a median follow-up of 35 months, actual patient survival rates were 82% in the SLT group and 88% in the LRT group. Actual graft survival rates were 76% and 81%, respectively. The incidence of primary nonfunction was 12% in the SLT group and 2.3% in the LRT group. Liver function parameters (prothrombin time, factor V, bilirubin clearance) and surgical complication rates did not differ significantly. In the SLT group, mean cold ischemic time was longer than in the LRT group. Serum values of alanine aminotransferase during the first postoperative week were significantly higher in the SLT group. In the LRT group, there were more grafts with signs of fatty degeneration than in the SLT group.

CONCLUSIONS

The short- and long-term outcomes after LRT and SLT did not differ significantly. To avoid the risk for the donor in LRT, SLT represents the first-line therapy in pediatric liver transplantation in countries where cadaveric organs are available. LRT provides a solution for urgent cases in which a cadaveric graft cannot be found in time or if the choice of the optimal time point for transplantation is vital.

First experience with basiliximab in pediatric liver graft recipients

Several studies have shown a significant reduction of acute cellular graft rejection in adult liver and kidney graft recipients treated with monoclonal anti-interleukin-2 (IL-2)-receptor antibodies. The mechanism was inhibition of activated T-helper cells by blocking the alpha-chain (CD25) of the IL-2 receptor. The pilot study described here evaluated the use of basiliximab in pediatric liver transplantation (LTx), which is the first report on its use in children. Fifty-two liver-transplanted children were analyzed in this study. A matched-pair historical control group (n = 26) received cyclosporin A (CsA) and prednisolone, and patients in the basiliximab group (n = 26) were treated with low-dose CsA and basiliximab (after reperfusion and on day 4 post-transplant). The incidences were compared of acute graft rejections, infectious complications, and the adverse effects of immunosuppressive medication within the first 6 months post-transplant. The incidence of acute rejection was significantly higher in the control group (61.5% vs. 11.5%, p = 0.0004). The frequency of infectious complications was similar (46.1% vs. 53.8%). Patients in the basiliximab group showed less arterial hypertension; however, the differences were not statistically significant (30.7% vs. 7.7%, p = 0.07). Nephrotoxicity, hepatotoxicity or neurotoxicity were only seen in the control group (7.7%; 3.8%; 3.8%, respectively). Hence, the use of basiliximab in combination with CsA and steroids in pediatric liver transplant recipients is safe and reduces the incidence of acute graft rejection. Further studies are needed to confirm our preliminary results and to analyze long-term effects on post-transplant lymphoproliferative disease, chronic rejection, and patient survival.

Th2 cytokine profile in infants predisposes to improved graft acceptance after liver transplantation

BACKGROUND

The T helper cell type 1 (Th1) cytokines interleukin (IL)-2 and interferon (IFN)-gamma are mediators of acute graft rejection after liver transplantation and Th2 cytokines, such as IL-4 and IL-10, may have a protective role and correlate with graft acceptance. To test the hypothesis that infants aged <1 year have an immunological advantage with regard to graft acceptance because of a partially immature immune system with a physiological balance toward a Th2 cytokine profile, we conducted the present study.

METHODS

We compared the T helper serum cytokine profiles in 105 infants and children after liver transplantation with or without acute graft rejection and analyzed the normal age-distributed concentrations of T helper cytokines in 51 healthy controls.

RESULTS

The incidence of acute graft rejection was as follows: 0 to 12 months, 26.8%; 1 to 3 years, 40.0%; and >3 years, 71.8%. There was a significantly lower incidence of acute rejection in infants 0 to 12 months of age compared with children >1 year (11/41 vs. 38/64; P=0.001). In healthy infants, significant increasing Th1 cytokine concentrations and decreasing Th2 cytokine concentrations were found with increasing age. Patients with acute rejection had significantly higher values of Th1 cytokines compared with nonrejecting subjects, who had significantly higher concentrations of Th2 cytokines. A longitudinal analysis of serum cytokines from patients showed that changes of the cytokine patterns in the follow-up did not differ significantly from preoperative values, except in the 4 weeks posttransplant.

CONCLUSIONS

We conclude from the data that the physiological balance toward a Th2 cytokine profile of infants in the first months of life predisposes to improved graft acceptance. Transplantation of children with biliary atresia as early as possible, avoiding Th1 stimulation by recurrent infections and vaccinations, may have a positive impact on overall tolerance.

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.

B-cell dysfunction and depletion using mycophenolate mofetil in a pediatric combined liver and kidney graft recipient

The use of mycophenolate mofetil (MMF) in combination with cyclosporin A (CsA) and steroids is well established after kidney transplantation (Tx) in children. A 9-yr-old girl with primary hyperoxaluria type 1 and systemic oxalosis underwent a combined kidney and liver Tx at our institution. The post-operative immunosuppression consisted of CsA, prednisolone, and MMF. Four weeks post-transplant the girl suffered from a severe urinary tract infection caused by Pseudomonas aeruginosa, when the serum immunoglobulin G (IgG) concentration was found to be critically low (<1.53 g/L). Additionally, there was an isolated B-cell depletion (240/microL) at that time. In the following course, the B-cell count was significantly diminished until the MMF was stopped 13 weeks post-transplant. As a result of the very low serum IgG concentration, intravenous immunoglobulin (IVIG) substitution was necessary. There was no significant loss of immunoglobulins in the ascites and urine and no other medication with possible side-effects on B cells was given. We suggest that MMF can lead to suppressed IgG production by B cells and can cause a defective differentiation into mature B cells. In vitro studies demonstrated these effects of MMF on B cells, but no in vivo cases of this phenomenon have been reported. B-cell counts and serum IgG concentrations returned to normal values after discontinuing the MMF. As we can assume that the observed B-cell dysfunction and depletion were MMF related, we suggest that serum IgG concentrations should be monitored when MMF is used after solid-organ Tx.

Interleukin-1 receptor antagonist in ascites indicates acute graft rejection after pediatric liver transplantation

Acute graft rejection is one of the most frequent complications after pediatric liver transplantation (LTx). In clinical practice, it is sometimes difficult to differentiate acute cellular graft rejection from other complications because clinical and chemical findings are often nonspecific. We therefore investigated the value of cytokine quantification in drained ascites, in addition to quantification of cytokine concentrations of serum, in 30 children in the first 2 weeks after orthotopic liver transplantation (OLT). Six of 30 patients showed acute graft rejection, with rising levels of alanine aminotransferase (ALT) and alpha-glutathione-S-transferase (alpha-GST) in serum up to 24 h prior to biopsy-proven rejection. There were no significant elevations of interleukin-2 receptor (IL-2r) and interleukin-6 (IL-6) in serum and ascites. In contrast to these findings, the concentration in ascites of the interleukin-1 receptor antagonist (IL-1ra) increased 48 h before rejection was proven by liver biopsy (p < 0.01, in comparison with the non-rejecting group, n = 24). The IL-1ra concentration in ascites was up to 11-fold higher than in serum during rejection (15.43 vs. 1.38 ng/mL). Two children with early infectious complication showed no significant increase in ascitic IL-1ra concentration. We conclude from these data that quantification of IL-1ra in ascites indicates the start of graft rejection after LTx. As long as abdominal drainage is performed, this non-invasive procedure may be of additional value in differential diagnoses and early diagnosis of rejection.

Intensive care management after pediatric liver transplantation: a single-center experience

A retrospective study was conducted to determine the significance of intensive care management on outcome after liver transplantation (LTx) in children. Of 195 transplants performed in 162 children, factors affecting morbidity and mortality were documented during the post-operative intensive care unit (ICU) stay. To assess the gain in experience of ICU management, we compared mean ventilation time and stay in the ICU as well as mortality, incidence of surgical complications, infections, and rejection episodes, during three different time-periods (October 1991-August 1994, September 1994-July 1996, and August 1996-February 1998). The time spent by patients in the ICU (9.7 days vs. 7.9 days vs. 4.7 days, p < 0.001) and time on ventilation (5.2 days vs. 3.1 days vs. 1.2 days, p < 0.001) were significantly reduced over the duration of the study. The overall mortality was 18.0% (n = 30) and 76.7% (n = 23) of these deaths occurred during the early post-operative period in the ICU. The incidence of severe surgical complications decreased significantly over time, and the application of intra-operative Doppler ultrasound since 1994 led to detection of 27 correctable vascular complications. The overall incidence of acute cellular rejection episodes in our center was 64.1%: 43.5% of the infectious episodes occurred in the ICU (bacterial 70.2%, viral 12.3%, and fungal 17.5%). The main side-effect from immunosuppressive drugs was arterial hypertension in 29% of the patients. We conclude that our efforts to improve intensive care management and monitoring were the key elements in reducing morbidity and mortality after pediatric LTx.

Long-term results of pre-emptive liver transplantation in primary hyperoxaluria type 1

In primary hyperoxaluria type 1 (PH 1), deficiency or mistargeting of hepatic alanine glyoxylate aminotransferase (AGT) results in over-production of oxalate and hyperoxaluria, leading to nephrocalcinosis and development of end-stage renal disease (ESRD) in the majority of patients. Renal transplantation (Tx) alone carries a high risk of disease recurrence as the metabolic defect is not cured. Therefore, combined liver/kidney Tx is recommended for patients with ESRD. An alternative approach is to cure PH 1 by pre-emptive isolated liver Tx (PLTx) before ESRD has occurred, but this approach has been carried out only occasionally and there are no uniformly accepted recommendations concerning the timing of this procedure. We report follow-up 3-5.7 yr after performing successful PLTx in four children (at the age of 3-9 yrs) with PH 1 prior to the occurrence of ESRD (glomerular filtration rate [GFR] range 27-98 mL/min/1.73 m2). There was no mortality or long-term morbidity associated with the Tx procedure. Plasma and urinary oxalate levels normalized rapidly within 4 weeks, and renal function did not deteriorate under immunosuppression, even in one patient with advanced chronic renal failure (GFR 27 mL/min/1.73 m2) who showed a stable course for more than 5.7 yrs. Although treatment must be individualized in this severe metabolic disorder, and PLTx has to be regarded as an invasive procedure, we consider that PLTx should be offered and considered early in the course of PH 1. PLTx cures the metabolic defect in PH 1 and can help to prevent, or at least delay, the progression to ESRD and systemic oxalosis.

Detection and monitoring of intracranial pressure dysregulation in liver failure by ultrasound

BACKGROUND

Development of elevated intracranial pressure (ICP) in hepatic failure indicates poor prognosis. Its detection by invasive methods poses methodological problems. We applied ultrasound studies of the optic nerves to noninvasively estimated ICP status.

METHODS

A total of 22 pediatric patients with hepatic failure were examined by serial B scan ultrasound and followed up clinically. Outcome was scored as survival or death due to multiorgan failure (MOF) or raised ICP. In 18 patients, transplantations were performed.

RESULTS

Four patients died before transplantation was possible (raised ICP: n=3, MOF: n=1). After OLT there were 10 survivors and 8 patients died (MOF: n=3, raised ICP: n=5). In 10 patients we found optic nerve sheath diameter (ONSD) above normal limits. Eight patients died, mostly because of raised ICP (n=7). Only 2 of the 10 survivors experienced a transient ONSD increase, steadily normalized after transplantation. Preoperatively, normal ONSD was detected in four of seven patients. The outcome of these four cases was clearly superior (three survivors and one MOF) compared with abnormal pre-OLT ultrasound findings (raised ICP: n=3).

CONCLUSION

Patients with poor prognosis related to raised ICP in pediatric liver failure can be identified by ultrasound measurement of ONSD without the disadvantages of invasive procedures. Although the exact intracranial pressure level cannot be deduced from single examinations, ONSD trends can reflect the evolution of ICP in hepatic encephalopathy.

Living-donor liver transplantation in children

INTRODUCTION

Living-related liver transplantation (LRLT) for paediatric recipients was developed 10 years ago to overcome the high mortality on the waiting list. Since then, liver transplantation programs around the world have begun to employ this method with encouraging results. This review describes the actual status of LRLT in children, aspects of donor selection, donor risks, and surgical technique, as well as an update of the results of the leading LRLT programs in the world. The donor operation has matured to the stage of being a standardised, teachable procedure with a low risk of morbidity or mortality. However, there is a percentage of potential donations that have to be declined for medical or socio-psychological reasons. LRLT provides grafts of excellent quality and short cold ischemic times. A major advantage is the fact that the optimal moment for the transplantation procedure can be chosen. Together with split-liver techniques, LRLT has a positive effect on the general situation of the paediatric waiting list for liver transplantation, with a reduction of pre-transplant mortality to nearly 0%.

Liver transplantation in children: long-term outcome and quality of life

Liver transplantation has become a standard therapy in acute and chronic liver failure. Since 1968, 2554 paediatric patients receiving a liver transplant have been registered in the European Liver Transplant Registry (ELTR). Compared with 22,600 total transplants registered in the ELTR over the same period of time this means that about 10% of all liver transplants performed in Europe concern paediatric recipients, aged from 0 to 15 years. The indications in the paediatric population differ significantly from those of adult patients: More than 50% of patients suffer from cholestatic disorders, followed by hepatic based metabolic disorders, acute liver failure, non-cholestatic cirrhosis and liver tumours. The results of liver transplantation in paediatric patients have improved remarkably since the early 1980s. In 1997 a survival rate of 80% is almost the international standard. This improvement is due to the use of better immunosuppressive agents such as cyclosporin A and tacrolimus, followed by improvement in surgical techniques and finally by improvement in intensive care, better diagnostic tools for viral, bacterial and fungal infections and corresponding appropriate therapies. Quality of life as a measure of transplant results has not been sufficiently studied. The majority of paediatric liver transplant recipients has a good quality of life; only 10% suffer from significant morbidity. The impact of pretransplant damage to other organs such as brain, kidneys, bone and lungs and the influence of immunosuppression on somatic growth, neurological development, infection and metabolic balance are subjects of increasing concern.

CONCLUSION

The results available today show convincing evidence that liver transplantation is a therapeutic option in otherwise fatal hepatic disorders. Much effort, however, has to be made in order to achieve further improvements by increasing our knowledge of the pathophysiology of both pre- and posttransplant conditions.

Liver transplantation in metabolic disorders

Liver transplantation in pediatric patients represents about 10% of a total of 23,000 transplantations registered in the European Liver Transplantation Register (ELTR)since 1968. The pediatric patients show a specific spectrum of indications with cholestatic liver disorders ranking first, followed by hepatic based metabolic disorders. There has been a significant improvement of survival in transplantation since the early 80ies. The overall survival standard is nowadays in the range of 80%. There is a trend towards even better results in metabolic disorders. The clinical presentation of liver disease caused by metabolic disorders shows a wide range from acute liver, cerebral, cardiac and renal failure to chronic end stage liver, kidney and heart disease potentially complicated by hepatocellular carcinoma. In many cases, the diagnosis of a underlying metabolic disorder is very difficult and time consuming so the decision to do a liver transplantation may be necessary before a final diagnosis is established. Having these problems in mind, the consideration of absolute and relative contraindications for liver transplantation in metabolic disorders is even more difficult than it is already in cholestatic or inflammatory liver disorders. The individual evaluation of a patient suffering from a hepatic metabolic disorder must consider in addition the often dramatic restriction of quality of life due to rigorous dietary restrictions or other therapies. This makes clear that suitable methods to measure quality of life must be developed and applied in order to fulfill this goal. The extension of indications for liver transplantation even to disorders with only partial defects in otherwise healthy livers was possible by using innovative surgical techniques such as partial, living related, split, in situ split and auxiliary orthotopic transplantation. These techniques allowed to reduce the mortality on pediatric waiting lists significantly without restricting the general donor pool. However, living related liver transplantation is handicaped by the heterozygous status of the parent donor. This plays a role especially in patients with progressive familial intrahepatic cholestasis (PFIC) and Wilson's disease.

Hepatic thrombopoietin mRNA levels in acute and chronic liver failure of childhood

The liver is the main production site of the hormone thrombopoietin (TPO), the major regulator of megakaryopoiesis. To investigate the role of an impaired TPO gene expression in the pathogenesis of thrombocytopenia in pediatric patients suffering from liver failure, we measured hepatic TPO mRNA in children with acute or chronic end-stage liver disease undergoing orthotopic liver transplantation. Tissue samples for RNA extraction were obtained from 12 children with compensated cirrhosis (CC), 22 children with decompensated cirrhosis (DC), and 9 children with acute liver failure (ALF). TPO mRNA was quantitated by competitive polymerase chain reaction (PCR), following reverse transcription (RT). Furthermore, in 9 children with ALF, serum TPO levels were measured by enzyme-linked immunosorbent assay before and 10 to 14 days after liver transplantation. The hepatic TPO mRNA concentration was highest in children with CC (median, 50.9 amol/micrograms RNA). This value was significantly reduced in children with DC (30.2 amol/micrograms RNA) or ALF (13.8 amol/micrograms RNA). Children with ALF (139 cells/nL) or DC (200 cells/nL) had lower platelet counts than children with CC (368 cells/nL). The serum TPO concentration increased from a median of 156 pg/mL in patients with ALF to 547 pg/mL after liver transplantation. These results show that the thrombocytopenia in children with liver failure is associated with reduced hepatic TPO mRNA levels. It remains to be investigated whether the serum TPO level and platelet counts are markers for the severity of liver damage that may serve as a prognostic indicator.

[Mesentericoportal Rex-shunt as a treatment for extrahepatic portal vein thrombosis]

The most common cause of portal hypertension in children with healthy livers is the prehepatic block. A 7-year-old girl had presented with portal vein thrombosis after umbilical vein catheterization in the newborn period. She suffered from collateral circulation with recurrent bleeding episodes due to esophageal varices (stage III-IV) and developed hypersplenism. Ultrasound demonstrated an open branch of the left portal vein. Direct splenoportography showed an open and communicating superior mesenteric vein. Liver biopsy was normal. An autologous left jugular vein graft was used to create a bypass from the superior mesenteric vein to the umbilical portion of the left intrahepatic portal vein (mesentericoportal Rex-shunt). Postoperatively, normal intrahepatic portal vein flow was demonstrated by ultrasound. After 2 years of follow-up, the patient is asymptomatic with no signs of portal hypertension. In contrast to classic portosystemic shunt operations, this bypass restores physiological portal vein flow, thus avoiding the possible consequences of longterm portosystemic shunting and low-grade encephalopathy.

Uncommon missense and splice mutations and resulting biochemical phenotypes in German patients with X-linked chronic granulomatous disease

Chronic granulomatous disease is an inherited disease characterized by the inability of phagocytes to generate normal amounts of superoxide, leaving patients susceptible to opportunistic, life-threatening infections. In the majority of cases, cytochrome b558 is absent in the X-chromosomal form of CGD. However, the neutrophils from six of nine X-linked CGD patients, reported here, expressed normal or decreased amounts of this cytochrome and are referred to as "variant" forms. In three of these six variant patients, a roughly proportional decrease in cytochrome b558 expression and production of H2O2 were found. In two cases this phenotype could be well explained by special splice mutations, whereas in the third case it was caused by a missense mutation, predicting Ser 193-->Phe. In the other three variant patients, cytochrome b558 expression and H2O2 production were clearly disproportionate as the generation of H2O2 was much more decreased than cytochrome expression. Missense mutations also were found in these cases. One of these mutations, predicting Leu 546-->Pro and affecting the putative nicotinamide adenine dinucleotide phosphate binding site, led to normal levels of cytochrome b558 expression and reduced H2O2 production. In the other two mutations, predicting Pro 339-->His and His 338-->Tyr, the putative flavin adenine dinucleotide binding site was affected. This could explain the corresponding uncommon phenotypes, characterized by zero or trace amounts of H2O2 production and the expression of relatively high amounts of nonfunctional or low functional cytochrome b558, respectively. The only missense mutation found that prevented the expression of any cytochrome b558 was caused by a predicted His 222-->Arg exchange in one of the three classic cases. The two other classic phenotypes were caused by splice mutations.

The Hamburg liver transplant program

The program of the University of Hamburg is exemplary of the problems faced by programs with rapid growth. Establishing expertise at all levels is essential to shorten the inevitable learning curve. The combination of an adult and a pediatric program was an ideal environment for the development of living donation and cadaveric in-situ split liver transplantation as complimentary solutions to eliminate pediatric mortality on the waiting list without affecting the chances of adult liver transplant candidates.

High-performance liquid chromatography-coulometric electrochemical detection of ubiquinol 10, ubiquinone 10, carotenoids, and tocopherols in neonatal plasma

A micromethod for the rapid simultaneous determination of several lipophilic antioxidants in plasma from newborn infants is presented. Because only 5 microliters of plasma is required, the procedure lends itself for repetitive use in very immature infants at risk for developing so-called "oxygen radical diseases of the premature." The method allows continuous monitoring of antioxidants in such patients and can easily be combined with monitoring other parameters of interest in this context. Reuse of blood samples taken routinely for the determination of hematocrit and bilirubin concentration is possible, reducing the blood volume required to be taken for the oxygen radical-related studies to virtually zero.