Renal failure in children with hepatic failure undergoing liver transplantation

Beyond Varices: Complications of Cirrhotic Portal Hypertension in Pediatrics

Complications of cirrhotic portal hypertension (PHTN) in children are broad and include clinical manifestations ranging from variceal hemorrhage, hepatic encephalopathy (HE), ascites, spontaneous bacterial peritonitis (SBP), and hepatorenal syndrome (HRS) to less common conditions such as hepatopulmonary syndrome, portopulmonary hypertension, and cirrhotic cardiomyopathy. The approaches to the diagnosis and management of these complications have become standard of practice in adults with cirrhosis with many guidance statements available. However, there is limited literature on the diagnosis and management of these complications of PHTN in children with much of the current guidance available focused on variceal hemorrhage. The aim of this review is to summarize the current literature in adults who experience these complications of cirrhotic PHTN beyond variceal hemorrhage and present the available literature in children, with a focus on diagnosis, management, and liver transplant decision making in children with cirrhosis who develop ascites, SBP, HRS, HE, and cardiopulmonary complications.

Extracorporeal renal and liver support in pediatric acute liver failure

The liver is the only organ which can regenerate and, thus, potentially negate the need for transplantation in acute liver failure (ALF). Cerebral edema and sepsis are leading causes of mortality in ALF. Both water-soluble and protein-bound toxins have been implicated in pathogenesis of various ALF complications. Ammonia is a surrogate marker of water-soluble toxin accumulation in ALF and high levels are associated with higher grades of hepatic encephalopathy, raised intracranial pressure, and mortality. Therefore, extracorporeal therapies aim to lower ammonia and maintain fluid balance and cytokine homeostasis. The most common and easily available modality is continuous kidney replacement therapy (CKRT). Early initiation of high-volume CKRT utilizing an anticoagulation regimen minimizing treatment downtime and delivering the prescribed dose is highly desirable. Ideally, extracorporeal liver-assist devices (ECLAD) should perform both synthetic and detoxification functions of the liver. ECLAD may temporarily replace lost liver function and serve as a bridge, either to spontaneous recovery or liver transplantation. Various bioartificial and biologic liver-assist devices are described in specialty literature, including molecular adsorbent recirculating system (MARS), single pass albumin dialysis (SPAD), and total plasma exchange (TPE); however, clinicians commonly use modalities easily available in intensive care units. There is a lack of standardization of indications for ECLAD, availability of different extracorporeal devices with varied technical approaches, and, of note, the differences in doses of ECLAD provided in clinical practice. We review the practicalities and evidence regarding these four artificial liver support devices in pediatric ALF.

Liver involvement in kidney disease and vice versa

The liver and kidneys are often similarly affected by a single disease. This is the case in metabolic, immunological, toxic, and infectious diseases, and in the different congenital malformation syndromes. Also, an enzymatic defect in an otherwise healthy liver or the consequences of advanced liver disease by itself can cause kidney disease as a secondary phenomenon. In this review, we describe numerous pathogenic mechanisms leading to dysfunction or malformations of the liver and kidneys in children. We encourage multidisciplinary management for optimal care. A combined liver-kidney transplantation is sometimes needed.

Effect of Continuous Renal Replacement Therapy on Outcome in Pediatric Acute Liver Failure

OBJECTIVES

To establish the effect of continuous renal replacement therapy on outcome in pediatric acute liver failure.

DESIGN

Retrospective cohort study.

SETTING

Sixteen-bed PICU in a university-affiliated tertiary care hospital and specialist liver centre.

PATIENTS

All children (0-18 yr) admitted to PICU with pediatric acute liver failure between January 2003 and December 2013.

INTERVENTIONS

Children with pediatric acute liver failure were managed according to a set protocol. The guidelines for continuous renal replacement therapy in pediatric acute liver failure were changed in 2011 following preliminary results to indicate the earlier use of continuous renal replacement therapy for both renal dysfunction and detoxification.

MEASUREMENTS AND MAIN RESULTS

Of 165 children admitted with pediatric acute liver failure, 136 met the inclusion criteria and 45 of these received continuous renal replacement therapy prior to transplantation or recovery. Of the children managed with continuous renal replacement therapy, 26 (58%) survived: 19 were successfully bridged to liver transplantation and 7 spontaneously recovered. Cox proportional hazards regression model clearly showed reducing hyperammonemia by 48 hours after initiating continuous renal replacement therapy significantly improved survival (HR, 1.04; 95% CI, 1.013-1.073; p = 0.004). On average, for every 10% decrease in ammonia from baseline at 48 hours, the likelihood of survival increased by 50%. Time to initiate continuous renal replacement therapy from PICU admission was lower in survivors compared to nonsurvivors (HR, 0.96; 95% CI, 0.916-1.007; p = 0.095). Change in practice to initiate early and high-dose continuous renal replacement therapy led to increased survival with maximum effect being visible in the first 14 days (HR, 3; 95% CI, 1.0-10.3; p = 0.063). Among children with pediatric acute liver failure who did not receive a liver transplant, use of continuous renal replacement therapy significantly improved survival (HR, 4; 95% CI, 1.5-11.6; p = 0.006).

CONCLUSION

Continuous renal replacement therapy can be used successfully in critically ill children with pediatric acute liver failure to provide stability and bridge to transplantation. Inability to reduce ammonia by 48 hours confers poor prognosis. Continuous renal replacement therapy should be considered at an early stage to help prevent further deterioration and buy time for potential spontaneous recovery or bridge to liver transplantation.

Dialysis-dependent acute kidney injury in children with end-stage liver disease: prevalence, dialysis modalities and outcome

BACKGROUND

Acute kidney injury (AKI) is a major complication in children with hepatic failure which leads to increased morbidity and mortality. The aim of this study was to provide paediatric data on the prevalence of dialysis-dependent AKI (dAKI), the feasibility and efficacy of dialysis methods and outcome.

METHODS

We conducted a retrospective analysis of 367 children listed for orthotopic liver transplantation (OLT) in our centre during the past decade.

RESULTS

Data on 30 children (15 boys, 15 girls) were compiled for retrospective analysis, and data on dialysis feasibility and efficacy were available for 26 of these. Median age was 3.5 (range 0.4-17.7) years. Median MELD (Model For End-Stage Liver Disease) score was 33. dAKI was caused by hepato-renal syndrome in 16 of the 30 children. Twenty-one patients were treated with continuous veno-venous haemofiltration (CVVH), and nine patients received peritoneal dialysis (PD). Overall mortality was 77%. Mortality within the PD-group was 100 % versus 67% in the CVVH-group (p = 0.039). Urea reduction rate within the first 24 h of treatment was 12.9% in the PD group and 23.5% in the CVVH group (p = 0.019).

CONCLUSIONS

Children with end-stage liver disease have a high risk for dAKI associated with high mortality. CVVH is associated with better efficacy and less mortality than PD.

Early detection of the graft failure after pediatric liver transplantation: a Bergamo experience

BACKGROUND

Effective indicators of the early graft failure after pediatric liver transplantation are currently a crucial question. The aim of this study was to analyze retrospectively laboratory parameters that may help anticipate an early graft loss (GL).

METHODS

The 131 pediatric liver transplantations, performed in our hospital from January 2002 to December 2005, were reviewed. Post-operative laboratory parameters, collected in the first 36 h of the Paediatric Intensive Care Unit (PICU) stay, were analyzed for children with both graft survival and GL. Receiver operating characteristics analysis was used to identify the optimal cut-off for the laboratory parameters. Multivariate logistic regression analysis was used to calculate the adjusted risk of GL for the prognostic parameters identified.

RESULTS

The mean age at transplant was 1.1 years. The two groups were comparable for all recipient and donor variables considered. Children with GL showed significantly higher levels of ammonia and transaminase at the admission to the PICU and higher levels of prothrombin time, creatinine, lactate and a lower level of platelets at the 36 h of PICU. The laboratory parameters over the cut-off value by the multivariate logistic regression identified all early thromboses earlier than Doppler ultrasound.

CONCLUSIONS

This study suggests that routine blood tests may help to anticipate an early loss of liver grafts in children after transplantation and may improve our diagnostic investigation in the case of thrombosis suspicion. Further validation by a prospective study is needed to carefully assess the sensitivity and specificity of the identified criteria.

Acute liver failure

Acute liver failure in children is a rare but potentially fatal disease. Causes of ALF in neonatal period are different from those in early or late childhood. Despite the improvement in the paediatric intensive care, liver transplantation remains the only effective treatment. Use of newer treatment modalities (liver assist devices and hepatocyte transplantation) is still in experimental phase. Management requires early recognition, prompt diagnosis of treatable condition, supportive therapy and prevention of complications hence these children should ideally be treated in a specialist unit.

New management options for end-stage chronic liver disease and acute liver failure: potential for pediatric patients

The management of children with end-stage chronic liver disease and acute liver failure mandates a multidisciplinary approach and intense monitoring. In recent years, considerable progress has been made in developing specific and supportive medical measures, but studies and publications have mainly concerned adult patients. Therapeutic approaches to complications of end-stage chronic liver disease and acute liver failure (e.g. refractory ascites, hepatorenal syndrome, encephalopathy, and cerebral edema) that may be applied to children are reviewed in this article.Mild-to-moderate ascites should be managed by modest salt restriction and oral diuretic therapy in the first instance. Large volume paracentesis associated with colloid volume expansion and diuretic therapy may be effective for acute relief. Treatment of hepatorenal syndrome type 1 with vasopressin analogs (terlipressin) is recommended prior to liver transplantation in order to improve renal function. Prevention and treatment of chronic hepatic encephalopathy are directed primarily at controlling the events that may precipitate hepatic encephalopathy and at reducing ammonia generation and increasing its detoxification or removal. In addition to reduction of gut ammonia production using non-absorbable disaccharides such as lactulose and/or antibacterials such as neomycin, sodium benzoate may be used on a long-term basis to prevent, stabilize, or improve hepatic encephalopathy. The management of hepatic encephalopathy in acute liver failure is considerably more unsatisfactory; treatment is aimed at preventing brain edema and intracranial hypertension. Extracorporeal liver support devices are now used commonly in critically ill children with acute renal failure, advanced hepatic encephalopathy, cerebral edema, intracranial hypertension, and severe coagulopathy. Continuous renal replacement therapy could potentially help support patients until liver transplantation is performed or liver regeneration occurs. The Molecular Adsorbent Recirculating System (MARS or albumin dialysis) is the liver support system most frequently used worldwide in adults and appears to offer distinct advantages over hepatocyte-based systems. There are no specific medical therapies or devices that can correct all of the functions of the liver. Apart from a few metabolic diseases presenting with severe liver dysfunction for which specific medical therapies may preclude the need for liver transplantation, liver transplantation still remains the only definitive therapy in most instances of end-stage chronic liver disease and acute liver failure. Future research should focus on gaining a better understanding of the mechanisms responsible for liver cell death and liver regeneration, as well as developments in hepatocyte transplantation and liver-directed gene therapy.

The clinical course of patients with type 1 hepatorenal syndrome maintained on hemodialysis

GOAL

Report the natural coarse of hepatorenal syndrome in 4 patients who were maintained on chronic hemodialysis.

BACKGROUND

The diagnosis of hepatorenal syndrome carries a grave prognosis with a mortality rate >90% and a median survival time of <2 weeks without orthotopic liver transplantation.

STUDY

We report the clinical course of 4 patients with hepatorenal syndrome who underwent long-term (greater than 3 weeks) hemodialysis in an attempt to bridge them to orthotopic liver transplantation. The etiologies of cirrhosis were: chronic hepatitis C infection (n = 2), alcoholic liver disease (n = 1), and primary sclerosing cholangitis (n = 1).

RESULTS

Mean survival time on hemodialysis was 236 days (range: 31 to 460 days). All patients survived their initial hospitalization and were discharged from the hospital. However, only one patient received orthotopic liver transplantation. Mean number of hospital admissions was 11 (range: 4 to 18) while receiving hemodialysis at an average rate of 2.2 (range: 1.1 to 5) admissions/patient month. Mean number of days spent in hospital while on hemodialysis support was 85 days (range: 15 to 199 days) at an average rate of 11.2 (range: 8.3 to 15) hospital days/patient month. An average of 33% (range: 26% to 48%) of the days of the prolonged survival on hemodialysis was spent in hospital.

CONCLUSION

Although our 4 patients with hepatorenal syndrome demonstrated long-term survival with hemodialysis, their prolonged survival was at the cost of a very heavy burden of morbidity and in-patient stay. The advisability of maintenance hemodialysis in patients with hepatorenal syndrome should be judged on an individual basis.

Development of a pediatric end-stage liver disease score to predict poor outcome in children awaiting liver transplantation

BACKGROUND

A pediatric end-stage liver disease (PELD) score for children with chronic liver disease using easily obtainable, objective, verifiable parameters, would be useful to prioritize children awaiting liver transplantation.

METHODS

Data from the Studies of Pediatric Liver Transplantation (SPLIT), a consortium of 29 U.S. and Canadian centers, were used to develop the PELD score. Two pretransplantation endpoints were evaluated: (1) death, n=884; and (2) death or moving to the intensive care unit (ICU), n=779. The analyses were restricted to children with chronic liver disease who were listed for a first transplant. Preliminary analyses of 17 possible factors yielded 6 parameters of interest: age <1 year, total bilirubin, international normalized ratio (INR), albumin, growth failure (height or weight Z score <-2), and calculated glomerular filtration rate. In a univariate Cox regression analysis, age, bilirubin, INR, and albumin were significant (P<0.01) predictors of both endpoints; glomerular filtration rate was not significant for either endpoint; and growth failure was significant for death/ICU but not death alone. In the multivariate analyses, age, bilirubin, and INR were significant for the death endpoint; and bilirubin, INR, growth failure, and albumin were significant for the death/ICU endpoint. From these results, three PELD models were evaluated to predict both outcomes at 3 and 6 months: PELD 1 (age, bilirubin, INR); PELD 2 (bilirubin, INR, albumin, growth failure); and PELD 3 (bilirubin, INR, albumin, growth failure, and age). The area under the receiver operating characteristic curve (AUC ROC) was used to compare models. For PELD 3, the most inclusive model, the AUC ROC at 3 months was 0.92 for death and 0.82 for "death-moved to ICU." A comparison of the AUC ROCs for the other models and for the model of end-stage liver disease ([MELD], the adult end-stage liver disease severity score model), none of which performed better than PELD 3, are presented.

CONCLUSION

A model using five objective parameters can accurately predict death or death-moved to ICU in children awaiting liver transplantation.

Renal transplantation following previous heart, liver, and lung transplantation: an 8-year single-center experience

BACKGROUND

Long-term follow-up of heart, liver, and lung transplantation has led to an increased recognition of secondary end-stage renal failure (ESRF) in transplant recipients. This study examines our center's experience with renal transplantation following previous solid organ transplantation.

METHODS

From January 1, 1992, to September 30, 1999, our center performed 18 renal transplants in previous solid organ recipients. During the same period, 815 total renal transplants were performed. One- and 3-year graft and patient survival, recipient demographics, donor type, and reason for transplantation were compared between these groups.

RESULTS

Of the 18 recipients, 7 had prior heart transplants, 4 had prior liver transplants, and 7 had prior lung transplants. Cyclosporine toxicity contributed to renal failure in 17 (94.4%) of the patients-either as a sole factor (11 patients) or in combination with hypertension, renal artery stenosis, or tacrolimus toxicity (6 patients). Kaplan-Meier 1- and 3-year patient survival was 82.9% and 73.7%, compared with 95.5% and 90.7% in all renal transplant recipients. No surviving patient has suffered renal allograft loss. Mean current creatinine level is 1.4 mg/dL.

CONCLUSIONS

Renal transplantation is an excellent therapy for ESRF following prior solid organ transplantation. One and 3-year patient and graft survival demonstrate the utility of renal transplantation in this patient population.

Renal function before and long after liver transplantation in children

BACKGROUND

Renal dysfunction occurs in children with liver diseases and renal function is often further impaired after orthotopic liver transplantation (OLT). Inaccurate methods of determining renal function are used in many cases. We studied renal function with accurate methods before and repeatedly after OLT to analyze the effect of the underlying diseases, hypertension, and the immunosuppressive agents.

METHODS

A total of 46 children were studied both before and annually after OLT with clearances of inulin and paraaminohippuric acid to determine the glomerular filtration rate (GFR) and effective renal plasma flow (ERPF). The clearance of inulin was also compared with the formula creatinine clearance.

RESULTS

GFR and ERPF decreased from before to after OLT and decreased further during the first years after OLT. Patients with extrahepatic biliary atresia and with tumours showed higher GFR 1 year after OLT than those with metabolic and miscellaneous disorders. No significant change in GFR of individual patients occurred from the first to the last values determined at around 1 and 6 years after OLT. No difference in renal function was seen during the first years between patients treated with cyclosporine as compared to those treated with tacrolimus, but 4 years after OLT, the GFR was higher in the tacrolimus-treated patients. Patients on antihypertensive agents had lower GFR than the normotensive ones. There was no agreement between GFR, determined by clearance of inulin, and that calculated on the basis of serum creatinine and the height of the patients.

CONCLUSIONS

Renal function is reduced by OLT and decreases further during the first years after OLT. Patients with metabolic disorders and those on antihypertensive treatment have the lowest GFR. Determination of GFR by the formula creatinine clearance is inaccurate in children after liver transplantation.

Nephrotoxicity after orthotopic liver transplantation in cyclosporin A and FK 506-treated patients

Nephrotoxicity represents a serious side-effect of immunosuppression following orthotopic liver transplantation. In order to preserve the therapeutic potential of cyclosporin (CsA) and FK 506 in human liver transplantation and to differentiate the nephrotoxic action of either drug in a clinical setting, we evaluated the incidence of early and late nephrotoxicity in 121 patients, 60 randomly assigned to CsA- and 61 to FK 506-based immunosuppression. Early postoperative renal insufficiency (between POD0 and 30; SCr 1.5-3 mg/dl) was observed to a similar extent in patients treated with CsA (36.7%) and FK 506 (42.6%). Early postoperative acute renal failure (ARF; SCr > 3 mg/dl) occurred in 18.3%, regardless of the immunosuppressive management. Approximately 50% of patients with ARF required hemodialysis (CsA: 11.7%; and FK 506: 8.3%). Mean onset of hemodialysis in CsA-treated patients was POD1 and in FK 506-treated patients, POD6, which demonstrated a different time course of drug-specific nephrotoxicity of CsA and FK 506 in early ARF. All patients with early postoperative ARF requiring hemodialysis survived more than 1 year (100% survival). New onset of late ARF (between POD30 and 365), however, occurred in 6.5% under FK 506 and in 1.7% under CsA immunosuppression due to severe infections with the multiple organ failure syndrome. This observation was consistent with the assumption of over-immunosuppression rather than a primary nephrotoxic effect. Mortality of patients with late ARF requiring hemodialysis was 100%. Late renal insufficiency appeared in 23.3% of CsA- and in 29.4% of FK 506-treated patients, and represented a slowly progressing form of drug-specific nephrotoxicity. These preliminary results demonstrated a similar outcome in terms of early and late nephrotoxicity, but longer follow-up will delineate its overall efficacy and toxicity in humans.

Fading renal hyperfiltration in children following liver transplantation

In a prospective longitudinal study, we investigated the renal function (RF) of 23 children before and after orthotopic liver transplantation (OLT). The aim was to assess both the outcome of pretransplant hyperfiltration and the clinical nephrotoxic effects of cyclosporin A (CsA); children with decreased RF prior to OLT were therefore excluded. The RF study of the 13 remaining patients included glomerular filtration rate (GFR) and effective renal plasma flow (RPF) measured by inulin (Cin: mL/min/1.73 m2) and para-amino hippurate (Cpah: mL/min/1.73 m2) clearances, respectively. Hyperfiltration prior to OLT was observed in six children, i.e. Cin>170 [range 172-230] and Cpah>800 [808-1,133]. A significant decrease in RF was noted as soon as 6 months after OLT: Cin (mean+/-SD)=107+/-23 vs. 158+/-46 (p<0.003); Cpah=583+/-119 vs. 791+/-243 (p<0.004). This was due to loss of hyperfiltration in the six children, as there was no significant difference in RF before and 6 months after OLT in the other seven children. With a 36-month follow-up, there was no correlation between CsA trough blood level and RF. In conclusion, following OLT, RF underwent early changes owing to loss of prior hyperfiltration in children without impaired RF before OLT. In addition, no evidence of CsA nephrotoxicity was found and RF remained stable during follow-up.

Advances in pediatric liver and intestinal transplantation

BACKGROUND

Significant progress has been made with liver and intestinal transplantation in pediatric patients. Shortage of whole-organ cadaveric grafts has resulted in a high mortality rate for children awaiting transplantation. New surgical procedures such as split-liver transplantation and living-related liver transplantation have evolved over the last decade to maximize donor utilization in pediatric patients.

METHODS

In this article we review the current indications and contraindications for liver and intestinal transplantation in children, the surgical innovations to expand an exceedingly small cadaveric liver pool, postoperative management, and the impact on patient and graft survival.

RESULTS

Reduced-size liver transplantation provides children with much needed small grafts; however, split-liver transplantation may eliminate the need for reduced-size and living-related liver transplantation except in urgent situations.

CONCLUSION

Liver transplantation is a durable procedure that provides excellent long-term survival. The use of living-related and split-liver transplantation has dramatically reduced the waiting periods for children and improved survival. In the past decade significant progress has been made with intestinal transplantation owing to improvements in surgical technique, immunosuppressive agents, and early identification and treatment of postoperative complications.

Liver transplantation. The pediatric challenge

Successful liver transplantation in a child is often a hard-won victory, requiring all the combined expertise of a dedicated pediatric transplant team. This article outlines the considerable challenges still facing pediatric liver transplant physicians and surgeons. In looking to the future, where should priorities lie to enhance the success already achieved? First, solutions to the donor shortage must be sought aggressively by increasing the use of from split-liver transplants, judicious application of living-donor programs, and increasing the donation rate, perhaps by innovative means. The major immunologic barriers, to successful xenotransplantation make it unlikely that this option will be tenable in the near future. Second, current immunosuppression is nonspecific, toxic, and unable to be individually adjusted to the patient's immune response. The goal of achieving donor-specific tolerance will require new consideration of induction protocols. Developing a clinically applicable method to measure the recipient's immunoreactivity is of paramount importance, for future studies of new immunosuppressive strategies and to address the immediate concern of long-term over-immunosuppression. The inclusion of pediatric patients in new protocols will require the ongoing insistence of pediatric transplant investigators. Third, the current immunosuppressive drugs have a long-term morbidity and mortality of their own. These long-term effects are particularly important in children who may well have decades of exposure to these therapies. There is now some understanding of their long-term renal toxicity and the risk of malignancy. New drugs may obviate renal toxicity, whereas the risk of malignancy is inherent in any nonspecific immunosuppressive regimen. Although progress is being made in preventing and recognizing PTLD, this entity remains an important ongoing concern. The global effect of long-term immunosuppression on the child's growth, development, and intellectual potential is unknown. Of particular concern is the potential for neurotoxicity from the calcineurin inhibitors. Fourth, recurrent disease and new diseases, perhaps potentiated by immunosuppressive drugs, must be considered. Already the recurrence of autoimmune disease and cryptogenic cirrhosis have been documented in pediatric patients. Now, a new lesion, a nonspecific hepatitis, sometimes with positive autoimmune markers, that may progress to cirrhosis has been recognized. It is not known whether this entity is an unusual form of rejection, an unrecognized viral infection, or a response to immunosuppressive drugs themselves. Finally, pediatric transplant recipients, like any other children, must be protected and nourished physically and mentally if they are to fulfill their potential. After liver transplantation the child's growth, intellectual functioning, and psychologic adaptation may all require special attention from parents, teachers, and physicians alike. There is limited understanding of how the enormous physical intervention of a liver transplantation affects a child's cognitive and psychologic function as the child progresses through life. The persons caring for these children have the difficult responsibility of providing services to evaluate these essential measures of children's health over the long term and to intervene if necessary. Part of the transplant physician's our duty to protect and advocate for children is to fight for equal access to health care. In most of the developing world, economic pressures make it impossible to consider liver transplantation a health care priority. In the United States and in other countries with the medical infrastructure to support liver transplantation, however, health care professionals must strive to be sure that the policies governing candidacy for transplantation and allocation of organs are applied justly and uniformly to all children whose lives are threatened by liver disease. In the current regulatory climate that increasingly takes medical decisions out of the hands of physicians, pediatricians must be even more prepared to protect the unique and often complicated needs of children both before and after transplantation. Only in this way can the challenges of the present and the future be met.

Late-onset renal failure after liver transplantation: role of posttransplant alcohol use

BACKGROUND

Late-onset renal failure is being increasingly recognized as a complication in patients undergoing liver transplantation for hepatitis C virus (HCV). However, its precise incidence, predisposing risk factors, and impact on outcome after liver transplantation, have not been defined.

METHODS

The development of late-onset renal failure (defined as serum creatinine persistently >2.0 mg/dl, occurring more than 6 months posttransplant) was assessed in 120 consecutive liver transplant recipients who survived at least 6 months after transplantation. Fifty-seven percent (68/120) of the patients had undergone transplantation for liver disease due to HCV. The median follow-up was 5 years.

RESULTS

Late-onset renal failure developed in 28% (33/120)of the patients. Posttransplant alcohol use (P=0.0001), posttransplant diabetes (P=0.0042), and recurrent HCV hepatitis (P=0.019) were significantly associated with late onset renal failure. In multivariate analysis, alcohol use (O.R. 10.7, 95%; CI 2.4-35.9, P=0.001) and diabetes (O.R. 2.1, 95%; CI 1.1-9.9, P=.03) were independently significant predictors of late onset renal failure. When only patients transplanted for HCV were analyzed, posttransplant alcohol use (P=0.004) was the only significant independent predictor of late-onset renal failure. HCV genotype 1b, as compared with other HCV genotypes, was associated with a higher rate of late-onset renal failure in patients with HCV; 70% of the patients with genotype 1b versus 32% of those with 1a and 33% of those with 2b, developed late onset renal failure (P=0.03). At a median follow up of 5 years, mortality in patients with HCV with late-onset renal failure was 52% as compared with 2% in those without renal failure (P=.0001).

CONCLUSION

Late-onset renal failure in patients with HCV portended a grave outcome. Alcohol use was an independent predictor of late-onset renal failure in patients with HCV and represents a potentially modifiable risk factor for late-onset renal failure in these patients.

Current results and evolving indications for liver transplantation in children

Liver transplantation continues to be successful and effective treatment for acute and chronic liver failure, and many important lessons have been learned. The development of innovative operative techniques has much reduced the waiting list mortality rate and has extended transplantation to younger and sicker children and to those with functionally normal livers who may benefit from auxiliary liver transplantation. The incidence and range of postoperative complications have improved with increased medical and surgical expertise. As information on long-term outcome for liver transplantation is gained, it is clear that many children will benefit from early elective liver transplantation before the development of significant growth or psychosocial retardation. Early transplantation is also indicated in children with cirrhosis and intrapulmonary shunting or cystic fibrosis with moderate lung disease. During the same period, evolving medical therapy has altered the natural history, patient selection, and timing of transplantation in children with tyrosinaemia type I, primary bile acid disorders, neonatal haemochromatosis, and potentially, cystic fibrosis. It is now clear that children with significant multisystem disease, such as mitochondrial disorders or severe systemic oxalosis, are no longer suitable candidates for liver transplantation. The successful development of liver transplantation has brought good quality life to many children and their families. There are still many lessons to learn and there are future challenges such as the ever-increasing problems of donor scarcity and the search for potent but less toxic immunosuppressive agents.

The hepatorenal syndrome

Hepatorenal syndrome may occur in any form of severe liver disease. It appears less common in children than adults, but still carries a poor prognosis. There are several factors involved in its aetiology, including a decreased renal perfusion pressure, activation of the renal sympathetic nervous system and increased synthesis of several vasoactive mediators, which may modulate glomerular filtration by acting as both renal vasoconstrictors and dynamic regulators of the glomerular capillary ultrafiltration coefficient, through their action on mesangial cells. This review will discuss the pathophysiology of the hepatorenal syndrome and some of the principles of management of patients with renal failure and severe liver disease. The role of renal support and liver transplantation will also be covered.

Combined liver-kidney transplantation and the effect of preformed lymphocytotoxic antibodies

Thirty-eight sequentially placed liver and kidney allografts were evaluated with respect to patient and graft survival, and the influence of preformed lymphocytotoxic antibodies was analysed. The results suggest that the survival rate of combined liver and kidney transplantation is similar to the survival rate of liver transplantation alone. Sequentially placed kidney allografts may be protected from hyperacute rejection in the presence of donor specific lymphocytotoxic antibodies, but not in all instances. Both patient and kidney allograft survival was lower in positive crossmatch patients (33% and 17% respectively) than in negative crossmatch patients (78% and 75%). High levels of panel reactive antibodies (> 10%) also appeared to have a deleterious effect on survival, although the majority of the patients who failed also had a positive crossmatch. Although performed lymphocytotoxic antibodies are not an absolute contraindication to combined liver-kidney transplantation, they do appear to have a deleterious effect on long-term graft survival. However, more correlation with clinical parameters is needed.

Should liver transplantation be performed before advanced renal insufficiency in primary hyperoxaluria type 1?

Primary hyperoxaluria type 1 (PH1) is a rare recessive autosomal inborn error of glyoxylate metabolism leading to oxalate retention, the first target of which is the kidney. The disease is caused by a defect of the liver-specific peroxisomal enzyme alanine: glyoxylate aminotransferase. Patients with pyridoxine-resistant forms of PH1 usually require organ replacement therapy, i.e. liver transplantation to supply the deficient enzyme and/or kidney transplantation to replace the affected organ. The current experience of the management of PH1 has emphasized two main points: (1) end-stage renal failure must be avoided since it increases dramatically the risk of systemic involvement, (2) the correction of oxalate overproduction and organ overload requires the removal of the host liver. Practical attitudes towards these ideas are difficult to assess and an individualized strategy is therefore required. Isolated kidney transplantation should be limited to adult patients with late-onset and a mild course of the disease. The present experience of combined liver-kidney transplantation was gained mainly in adult patients with severe systemic involvement; the 3-year patient survival rate recently increased to 82%. This figure might be improved if the procedure were performed earlier while the glomerular filtration rate (GFR) is above 25 ml/min per 1.73 m2. Isolated liver transplantation should be considered in carefully selected children with severe forms of pyridoxine-resistance (PH1) before GFR has dropped to less than 30 ml/min per 1.73 m2; it seems to be indicated especially in the presence of a rapid decline of GFR in the preceding year.(ABSTRACT TRUNCATED AT 250 WORDS)

Glomerular abnormalities in children undergoing orthotopic liver transplantation

A prospective study of renal function was undertaken on an unselected group of 8 children with chronic progressive liver disease on whom a renal biopsy was performed subsequently at the time of orthotopic liver transplantation. Two patients had abnormal urinalyses and 2 elevated urinary albumin/creatinine ratios. The remainder had no clinical evidence of renal dysfunction. All had normal serum creatinine concentrations. Glomerular abnormalities were present in all renal biopsies and were of two types: hepatic glomerulosclerosis (n = 5) and minor glomerular abnormalities (n = 3). IgM immunofluorescence was present in all biopsies and IgA in 6. Elevated serum immunoglobulin levels were observed in all patients, with IgM elevation in 6, IgA in 4 and IgG in 6. C3 and/or C4 were reduced in 5 patients and increased circulating immune complexes containing IgM were noted in 4. The clinical significance of these cirrhosis-associated glomerular abnormalities can only be established by long-term follow-up studies after orthotopic liver transplantation.

Peritoneal dialysis in end-stage renal disease patients with preexisting chronic liver disease and ascites

PURPOSE

Hemodialysis in patients with chronic liver disease and ascites may be complicated by intradialytic hypotension, limiting the amount of ultrafiltration and resulting in massive ascites. Successful maintenance peritoneal dialysis (PD) has not been previously reported as an alternative to hemodialysis in this population.

PATIENTS AND METHODS

Nine patients with chronic renal failure, chronic liver disease, and tense ascites prior to beginning PD are described. All chronic PD catheters were placed percutaneously by the nephrology staff. Seven patients were maintained primarily on continuous ambulatory peritoneal dialysis, whereas two were on intermittent peritoneal dialysis.

RESULTS

PD catheters were placed without serious hemorrhage or bowel injury. PD provided adequate clearance and volume maintenance for each patient. Fifteen episodes of peritonitis occurred in 18 patient-years of PD. All episodes of peritonitis were successfully treated with intraperitoneal antibiotics without catheter removal. Only one patient had a decline in the serum albumin level of 0.5 g/dL or more during the course of chronic PD. Three of the nine patients are still alive and on PD for durations of 18 to 24 months. One patient insidiously developed sclerosing peritonitis after 8 years on PD and is now on hemodialysis, and another patient switched to hemodialysis because she was no longer able to care for herself or to manage her PD. Four patients died while maintained on PD; three deaths were due to complications of liver failure within the first 4 months of PD and the fourth was due to empyema after 4 years of PD.

CONCLUSION

PD can be used successfully to treat chronic renal failure in patients with chronic liver disease and ascites when the liver disease itself is not rapidly fatal. PD may be better tolerated than hemodialysis and perhaps should be the renal replacement treatment of choice in these patients.

Prophylactic use of OKT3 in liver transplantation. A review

Liver rejection in the era of cyclosporine-based immunosuppression is approximately 60-70%. Approximately 15-25% of liver transplant patients will require hemodialysis following transplantation. These facts argue for a potent, less nephrotoxic immunosuppressive regimen, especially during the period of vulnerability to these events. Prophylactic use of OKT3 has been suggested as a means to decrease the need for hemodialysis while maintaining potent immunosuppression. The goal of this review is to examine potential benefits and pitfalls of this regimen. A lack of documentation of long-term patient and graft survival, the potential susceptibility to infectious complications, development of sensitization, and the cost must be weighed against the decreased need for hemodialysis and the control of early rejection episodes.

Severe hypertension after liver transplantation in alpha 1 antitrypsin deficiency

Five children with alpha 1 antitrypsin deficiency and terminal liver disease received liver grafts; all five became hypertensive and four developed hypertensive encephalopathy. There was evidence of renal disease preoperatively and renal biopsy specimens showed variable glomerulonephritic histology with IgA nephropathy in one, mesangial-proliferative changes in two, and mesangio-capillary glomerulonephritis type I in two. Four hypertensive episodes were preceded by a fall in creatinine clearance. The association of glomerulonephritis with alpha 1 antitrypsin deficiency in children is more common than has been recognised. Affected patients are prone to severe hypertension of probable renal origin after liver transplantation and the renal lesion may affect long term prognosis.

Primary hyperoxaluria type I

Primary hyperoxaluria type I is a metabolic disorder caused by the deficiency of the peroxisomal alanine:glyoxylate aminotransferase. The disease is inherited as an autosomal recessive trait. The clinical course is outlined based on data from 330 published cases. Diagnostic cornerstones are clinical parameters, urinary excretion of oxalate and glycolate, and the determination of enzyme activity in liver tissue. Principles of conservative treatment, e.g. volume load and pyridoxine substitution, are described as well as experience with different modes of dialysis and transplantation. Kidney transplantation is associated with a high rate of recurrence of the original disease despite excellent management resulting in many instances in early graft loss. Liver transplantation offers the possibility to correct the metabolic defect and to prevent the progression of crystal deposition in the body.

Acute and chronic renal failure in liver transplantation

We have performed a retrospective review of the incidence and etiologies of acute renal failure (ARF) in 105 adult patients receiving liver transplants. The prevalence of chronic renal failure was also determined. ARF occurred in 94.2% of these patients. Acute tubular necrosis was the leading cause of ARF and was associated with the highest mortality. Factors associated with increased mortality included: (1) peak serum creatinine greater than 3 mg/dl, (2) multiple liver transplants and (3) the need for dialysis. Pretransplant renal failure did not increase mortality. Chronic renal failure developed in 83% of patients at latest follow-up (mean: 30.5 +/- 7.9 months).

Use of OKT3 with cyclosporin and steroids for reversal of acute kidney and liver allograft rejection

OKT3 monoclonal antibody therapy was added to preexisting baseline immunosuppressive treatment with ciclosporin and steroids to treat rejection in 52 recipients of cadaveric livers and 10 recipients of cadaveric kidneys. Rejection was controlled in 75% of patients treated, often after high-dose steroid therapy had failed. Rejection recurred during the 17-month follow-up period, after completion of OKT3, in only 25% of the patients who had responded. The safety and effectiveness of this monoclonal therapy, added to ciclosporin and steroids, has been established in this study.