Renal graft outcome after combined liver and kidney transplantation in children: UCLA and UNOS experience

Combined liver-kidney transplantation in pediatric patients

Combined liver-kidney transplantation (CLKT) is a surgical procedure that involves transplanting both liver and kidney organs. There are two types of CLKT: simultaneous liver-kidney transplantation (smLKT) and sequential LKT (sqLKT). CLKT accounts for a small percentage of liver transplantations (LTs), particularly in pediatric cases. Nevertheless, the procedure has demonstrated excellent outcomes, with high survival rates and lower rejection rates. The main indications for CLKT in pediatric patients differ somewhat from that in adults, in which end-stage kidney disease after LT is the major indication. In children, congenital diseases are common reason for performing CLKT; the examples of such diseases include autosomal recessive polycystic kidney disease with congenital hepatic fibrosis which equally affects both organs, and primary hyperoxaluria type 1, a primary liver disease leading kidney failure. The decision between smLKT or sqLKT depends on the dominant organ failure, the specific pathophysiology, and available organ sources. However, there remain significant surgical and societal challenges surrounding CLKT. Innovations in pharmacology and genetic engineering have decreased the necessity for CLKT in early-diagnosed cases without portal hypertension or kidney replacement therapy. Nonetheless, these advancements are not universally accessible. Therefore, decision-making algorithms should be crafted, considering region-specific organ allocation systems and prevailing medical environments.

Autosomal Recessive Polycystic Kidney Disease: Diagnosis, Prognosis, and Management

Autosomal recessive polycystic kidney disease (ARPKD) is the rare and usually early-onset form of polycystic kidney disease with a typical clinical presentation of enlarged cystic kidneys and liver involvement with congenital hepatic fibrosis or Caroli syndrome. ARPKD remains a clinical challenge in pediatrics, frequently requiring continuous and long-term multidisciplinary treatment. In this review, we aim to give an overview over clinical aspects of ARPKD and recent developments in our understanding of disease progression, risk patterns, and treatment of ARPKD.

Long-term outcome after combined or sequential liver and kidney transplantation in children with infantile and juvenile primary hyperoxaluria type 1

Introduction

Combined or sequential liver and kidney transplantation (CLKT/SLKT) restores kidney function and corrects the underlying metabolic defect in children with end-stage kidney disease in primary hyperoxaluria type 1 (PH1). However, data on long-term outcome, especially in children with infantile PH1, are rare.

Methods

All pediatric PH1-patients who underwent CLKT/SLKT at our center were analyzed retrospectively.

Results

Eighteen patients (infantile PH1 n = 10, juvenile PH1 n = 8) underwent transplantation (CLKT n = 17, SLKT n = 1) at a median age of 5.4 years (1.5-11.8). Patient survival was 94% after a median follow-up of 9.2 years (6.4-11.0). Liver and kidney survival-rates after 1, 10, and 15 years were 90%, 85%, 85%, and 90%, 75%, 75%, respectively. Age at transplantation was significantly lower in infantile than juvenile PH1 (1.6 years (1.4-2.4) vs. 12.8 years (8.4-14.1), P = 0.003). Median follow-up was 11.0 years (6.8-11.6) in patients with infantile PH1 vs. 6.9 years (5.7-9.9) in juvenile PH1 (P = 0.15). At latest follow-up kidney and/or liver graft loss and/or death showed a tendency to a higher rate in patients with infantile vs. juvenile PH1 (3/10 vs. 1/8, P = 0.59).

Discussion

In conclusion, the overall patient survival and long-term transplant outcome of patients after CLKT/SLKT for PH1 is encouraging. However, results in infantile PH1 tended to be less optimal than in patients with juvenile PH1.

Fibrocystic liver disease: novel concepts and translational perspectives

Fibrocystic liver diseases (FLDs) comprise a heterogeneous group of rare diseases of the biliary tree, having in common an abnormal development of the embryonic ductal plate caused by genetically-determined dysfunctions of proteins expressed in the primary cilia of cholangiocytes (and therefore grouped among the "ciliopathies"). The ductal dysgenesis may affect the biliary system at multiple levels, from the small intrahepatic bile ducts [congenital hepatic fibrosis (CHF)], to the larger intrahepatic bile ducts [Caroli disease (CD), or Caroli syndrome (CS), when CD coexists with CHF], leading to biliary microhamartomas and segmental bile duct dilations. Biliary changes are accompanied by progressive deposition of abundant peribiliary fibrosis. Peribiliary fibrosis and biliary cysts are the fundamental lesions of FLDs and are responsible for the main clinical manifestations, such as portal hypertension, recurrent cholangitis, cholestasis, sepsis and eventually cholangiocarcinoma. Furthermore, FLDs often associate with a spectrum of disorders affecting primarily the kidney. Among them, the autosomal recessive polycystic kidney disease (ARPKD) is the most frequent, and the renal function impairment is central in disease progression. CHF, CD/CS, and ARPKD are caused by a number of mutations in polycystic kidney hepatic disease 1 (PKHD1), a gene that encodes for fibrocystin/polyductin, a protein of unclear function, but supposedly involved in planar cell polarity and other fundamental cell functions. Targeted medical therapy is not available yet and thus the current treatment aims at controlling the complications. Interventional radiology or surgical treatments, including liver transplantation, are used in selected cases.

Impact on the hepatic flow velocity after pediatric combined liver-kidney transplantation compared to isolated pediatric liver transplantation-A matched-pair analysis

BACKGROUND

Combined liver-kidney transplantation (CLKT) in children is still a rarely performed procedure. Our aim was to analyze the effect of the simultaneous transplantation of the kidney in pediatric CLKT on the liver graft flow velocity, and vascular complications compared to singular liver transplantation (LTX) in children.

METHODS

All pediatric CLKT performed at our institution from 1998 to 2016 were matched with singular LTX and retrospectively analyzed.

RESULTS

Overall 30 CLKT were performed in 28 children (median age 8 years, range 1-16) and matched with 30 children undergoing singular LTX (median age 7.9 years, range 1-16). No significant differences were found concerning the systolic peak flow velocity of the hepatic artery (HA) or the resistance index (RI). Vascular complications of the hepatic vessels occurred in 16.7% (CLKT) and 6.7% (LTX). The 1-/5- and 10-year patient survival was 93.3%/93.3% and 93.3% (CLKT) and 100%/100% and 92.9% (LTX). 1-/5-and 10-year liver graft survival was 76.7%/73.2% and 73.2% (CLKT) and 84.4%/75.9% and 69.6% (LTX).

CONCLUSION

The simultaneous transplantation of the kidney in CLKT had no negative impact on hepatic flow velocity or vascular complications. Frequent Doppler ultrasound examinations, accurate volume management, and avoidance of abdominal pressure might be an explanation for the results and an excellent graft- and patient survival.

Combined and sequential liver-kidney transplantation in children

Combined and sequential liver-kidney transplantation (CLKT and SLKT) is a definitive treatment in children with end-stage organ failure. There are two major indications: - terminal insufficiency of both organs, or - need for transplanting new liver as a source of lacking enzyme or specific regulator of the immune system in a patient with renal failure. A third (uncommon) option is secondary end-stage renal failure in liver transplant recipients. These three clinical settings use distinct qualification algorithms. The most common indications include primary hyperoxaluria type 1 (PH1) and autosomal recessive polycystic kidney disease (ARPKD), followed by liver diseases associated with occasional kidney failure. Availability of anti-C5a antibody (eculizumab) has limited the validity of CLKT in genetic atypical hemolytic uremic syndrome (aHUS). The liver coming from the same donor as renal graft (in CLKT) is immunologically protective for the kidney and this provides long-term rejection-free follow-up. No such protection is observed in SLKT, when both organs come from different donors, except uncommon cases of living donation of both organs. Overall long-term outcome in CLKT in terms of graft survival is good and not different from isolated liver or kidney transplantation, however patient survival is inferior due to complexity of this procedure.

Pediatric combined liver-kidney transplantation: a single-center experience of 18 cases

BACKGROUND

Experience in combined liver-kidney transplantation (CLKT) in children is limited.

METHODS

We conducted a retrospective study of all pediatric CLKTs performed at our medical institution between 1992 and 2013.

RESULTS

We identified 18 pediatric patients (9 girls) who had undergone CLKT at our institution during the study period. The median age [range] and body weight [range] of this patient group was 3.6 [1.0-18.6] years and 13 [10-40] kg, respectively; 11 patients weighed <15 kg at the time of CLKT. Indications for CLKT were primary hyperoxaluria (PH1; n = 14), association of hepatic fibrosis and end-stage renal disease (n = 3) and methylmalonic acidemia (n = 1). In the early postoperative period, eight patients required dialysis. Median stay in the pediatric intensive care unit was 10 [6-29] days. One patient died from cardiovascular disease 10 years after CLKT. There were no liver graft losses despite six acute liver rejection episodes, whereas four kidney grafts were lost. At last follow-up (6 [0.5-21] years) for patients with a functioning renal graft, the glomerular filtration rate was 71 [26-146] mL/min/1.73 m(2). In PH1 patients, urine oxalate normalized in six patients within 3 years after CLKT, but three patients still presented with elevated oxaluria at 1, 2 and 3 years after CLKT.

CONCLUSIONS

Pediatric CLKT provides encouraging results in the long term, even in the youngest patients.

Combined liver and kidney transplantation in children: analysis of renal graft outcome

BACKGROUND

Combined liver-kidney transplantation (CLKT) is the accepted treatment for patients with both liver failure and progressive renal insufficiency. Long-term outcome data for CLKT in children is sparse and controversy exists as to whether simultaneous CLKT with organs from the same donor confers immunologic and survival benefit to the kidney allograft. We report the long-term renal graft outcomes of 40 patients who had simultaneous CLKT.

METHODS

A retrospective analysis of kidney graft survival (time from transplantation to death, return to dialysis or last follow-up event) in all pediatric patients (age < 18 years old) who underwent CLKT from March 1994 to January 2015. A 1:1 ratio of controls (deceased donor kidney recipients from our centre matched for age (±2 years) at transplant, time from transplant (±1 year) and treated with the same immunosuppressive regime) to cases was used to compare outcome. Estimated glomerular filtration rate (e-GFR) was calculated using the Schwartz formula. Survival curves were determined using Kaplan-Meier analysis.

RESULTS

The kidney graft survival for CLKT patients was 87.4, 82, and 82 % at 1, 5, and 10 years; kidney graft survival for isolated KT patients were 97.2, 93, and 93 % at 1, 5, and 10 years (p = NS). There were two acute rejection episodes (5 %) in the CLKT group compared to five (12.5 %) episodes in the isolated KT group. There was no statistically significant difference in e-GFR at 1, 5, and 10 years in the two groups but there was a statistically significantly greater decline in e-GFR in the KT group compared to CLKT group from 5-10 years following transplant.

CONCLUSIONS

There are fewer acute rejection episodes following CLKT compared to isolated KT, and we noted a higher mean e-GFR at 1, 5, and 10 years with significantly lesser decline in e-GFR from 5 to 10 years in the CLKT group.

Kidney Versus Combined Kidney and Liver Transplantation in Young People With Autosomal Recessive Polycystic Kidney Disease: Data From the European Society for Pediatric Nephrology/European Renal Association-European Dialysis and Transplant (ESPN/ERA-EDTA) Registry

BACKGROUND

The choice for either kidney or combined liver-kidney transplantation in young people with kidney failure and liver fibrosis due to autosomal recessive polycystic kidney disease (ARPKD) can be challenging. We aimed to analyze the characteristics and outcomes of transplantation type in these children, adolescents, and young adults.

STUDY DESIGN

Cohort study.

SETTING & PARTICIPANTS

We derived data for children, adolescents, and young adults with ARPKD with either kidney or combined liver-kidney transplants for 1995 to 2012 from the ESPN/ERA-EDTA Registry, a European pediatric renal registry collecting data from 36 European countries.

FACTOR

Liver transplantation.

OUTCOMES & MEASUREMENTS

Transplantation and patient survival.

RESULTS

202 patients with ARPKD aged 19 years or younger underwent transplantation after a median of 0.4 (IQR, 0.0-1.4) years on dialysis therapy at a median age of 9.0 (IQR, 4.1-13.7) years. 32 (15.8%) underwent combined liver-kidney transplantation, 163 (80.7%) underwent kidney transplantation, and 7 (3.5%) were excluded because transplantation type was unknown. Age- and sex-adjusted 5-year patient survival posttransplantation was 95.5% (95% CI, 92.4%-98.8%) overall: 97.4% (95% CI, 94.9%-100.0%) for patients with kidney transplantation in contrast to 87.0% (95% CI, 75.8%-99.8%) with combined liver-kidney transplantation. The age- and sex-adjusted risk for death after combined liver-kidney transplantation was 6.7-fold (95% CI, 1.8- to 25.4-fold) greater than after kidney transplantation (P=0.005). Five-year death-censored kidney transplant survival following combined liver-kidney and kidney transplantation was similar (92.1% vs 85.9%; P=0.4).

LIMITATIONS

No data for liver disease of kidney therapy recipients.

CONCLUSIONS

Combined liver-kidney transplantation in ARPKD is associated with increased mortality compared to kidney transplantation in our large observational study and was not associated with improved 5-year kidney transplant survival. Long-term follow-up of both kidney and liver involvement are needed to better delineate the optimal transplantation strategy.

Pediatric combined liver-kidney transplantation: a 2015 update

PURPOSE OF REVIEW

The experience of combined liver-kidney transplantation (CLKT) is limited in pediatric populations. This strategy is, however, required in specific diseases such as metabolic diseases (namely primary hyperoxaluria type one and methylmalonic acidemia), autosomal recessive polycystic kidney disease, miscellaneous ciliopathies and atypical hemolytic uremic syndrome.

RECENT FINDINGS

Different series and registry studies have confirmed the feasibility of pediatric CLKT with encouraging results in the long term, even in the youngest and smallest patients, provided that highly trained multidisciplinary teams are involved in this global management. As such, the long-term outcomes after CLKT are currently comparable to that of isolated liver or kidney transplantations, even though the immediate postoperative period remains challenging.

SUMMARY

Some questions remain nevertheless unanswered, such as the respective place of combined versus sequential liver-kidney transplantation, especially in primary hyperoxaluria and autosomal recessive polycystic kidney disease. The aim of this review was therefore to provide a 2015 update on pediatric CLKT. In the future, international collaborative studies and registries may help to improve our knowledge of this rare and still highly challenging technique.

Outcomes of combined liver-kidney transplantation in children: analysis of the scientific registry of transplant recipients

Combined liver-kidney transplantation (CLKT) in children is uncommon and outcomes have not been well defined. Using the Scientific Registry of Transplant Recipients, data were analyzed on 152 primary pediatric CLKTs performed from October 1987 to February 2011, to determine their outcome in the largest series reported to date. Patient survival was 86.8%, 82.1% and 78.9% at 1, 5 and 10 years, liver graft survival was 81.9%, 76.5% and 72.6%, and kidney graft survival was 83.4%, 76.5% and 66.8%. By way of comparison, the Registry was queried for pediatric patient survival following isolated liver transplantation (LT) during the same time frame: 86.7%, 81.2% and 77.4% and following isolated kidney transplant (KT): 98.2%, 95.4% and 90% at 1, 5 and 10 years. In patients having undergone CLKT, primary hyperoxaluria was associated with reduced patient (p = 0.01), liver graft (p = 0.01) and kidney graft survival (p = 0.01). Furthermore, graft outcome following CLKT improved over the past decade (p = 0.04 for liver, p = 0.02 for kidney), but this did not translate into improved patient outcome (p = 0.2). All in all, our results confirmed that survival following LT was less than following KT, and that CLKT offered similar patient survival to isolated LT.

Kidney and liver transplantation in children with fibrocystic liver-kidney disease: data from the US Scientific Registry of Transplant Recipients: 1990-2010

The natural history and survival of children with fibrocystic liver-kidney disease undergoing solid organ transplantation have infrequently been described. We report outcomes in a cohort of US children with fibrocystic liver-kidney disease receiving solid organ transplants over 20 yr. Retrospective cohort study of pediatric transplant recipients with diagnoses of fibrocystic liver-kidney disease from 1/1990 to 3/2010, using data from the SRTR. Subjects were categorized by the first transplanted organ: LT, KT, or SLK. Primary outcomes were death, re-transplant, transplant of the alternate organ, or initiation of dialysis. Seven hundred and sixteen subjects were transplanted in this period. Median age at first transplant was 9.7 yr. Of the LT, 14 (19%) required a second liver transplant at median of 0.2 yr, and five (7%) required kidney transplant or dialysis at a median of 9.0 yr. Of the KT, 188 (31%) required a second kidney transplant or dialysis at a median of 5.9 yr. Twenty-nine (5%) subsequently received liver transplant at a median of 6.0 yr. Among patients in this registry, far more children underwent kidney than liver transplants. The risk of subsequently needing transplantation of an alternate organ was low.

Combined liver and kidney transplantation in children

Simultaneous combined liver-kidney transplantation (CLKT) is a rare operation in pediatric patients so that annually only 10-30 operations are performed worldwide. The main indications for CLKT are primary hyperoxaluria type 1 and autosomal recessive polycystic kidney disease. In addition, CLKT is indicated in individual patients with metabolic or cirrhotic liver diseases and end-stage kidney disease. The surgery and immediate post-operative management of CLKT remain challenging in infants and small children. The patients should be operated on before they become severely ill or develop major systemic manifestations of their metabolic disorder. The liver allograft is immunologically protective of the kidney graft in simultaneous CLKT, often resulting in well-preserved kidney function. The long-term outcome after CLKT is nowadays comparable to that of isolated liver and kidney transplantations.

The kidney in pediatric liver transplantation: an updated perspective

CKD continues to detract from the success of improved survival in pediatric liver transplantation, and its presence is likely under recognized. Here we review the literature regarding the prevalence, etiology, and management of renal dysfunction in pediatric liver transplant recipients. Long-term studies suggest the prevalence of CKD to be 25-38% by 5-10 yr post-transplant. While important, sole use of serum creatinine overestimates renal function in this population. Screening for and treatment of persistent proteinuria and hypertension as well as minimization of nephrotoxic insults are the mainstays to delay or prevent CKD progression. Office-based blood pressure measures are less sensitive than ABPM, which is specifically recommended by the American Heart Association for its ability to diagnose masked hypertension in pediatric liver transplant recipients. Long-term risk of CKD is predominantly secondary to CNI toxicity. CNI minimization protocols have shown promise in slowing progression of CKD while maintaining graft function, but large-scale randomized control trials with long-term follow-up are needed.

Predisposing factors of diminished survival in simultaneous liver/kidney transplantation

Since the adoption of the Model for End-Stage Liver Disease, simultaneous liver/kidney transplants (SLKT) have substantially increased. Recently, unfavorable outcomes have been reported yet contributing factors remain unclear. We retrospectively reviewed 74 consecutive adult SLKT performed at our center from 2000 to 2010 and compared with kidney transplant alone (KTA, N = 544). In SLKT, patient and death-censored kidney graft survival rates were 64 ± 6% and 81 ± 5% at 5 years, respectively (median follow-up, 47 months). Multivariable analyses revealed three independent risk factors affecting patient survival: hepatitis C virus positive (HCV+, hazard ratio [HR] 2.9, 95% confidence interval [CI] 1.1-7.9), panel reactive antibody (PRA) > 20% (HR 2.8, 95% CI 1.1-7.2) and female donor gender (HR 2.9, 95% CI 1.1-7.9). For death-censored kidney graft survival, delayed graft function was the strongest negative predictor (HR 8.3, 95% CI 2.5-27.9), followed by HCV+ and PRA > 20%. The adjusted risk of death-censored kidney graft loss in HCV+ SLKT patients was 5.8 (95% CI 1.6-21.6) compared with HCV+ KTA (p = 0.008). Recurrent HCV within 1 year after SLKT correlated with early kidney graft failure (p = 0.004). Careful donor/recipient selection and innovative approaches for HCV+ SLKT patients are critical to further improve long-term outcomes.