Marginal parental donors for pediatric living donor liver transplantation

Improved survival of pediatric deceased donor liver transplantation recipients after introduction of the pediatric prioritization system: Analysis of data from a Japanese national survey

BACKGROUND

In Japan, there has never been a national analysis of pediatric deceased donor liver transplantation (pDDLT) based on donor and recipient factors. We constructed a Japanese nationwide database and assessed outcomes of pDDLT focusing on the pediatric prioritization system introduced in 2018.

METHODS

We collected data on pDDLTs (<18 years) performed between 1999 and 2021 from the Japan Organ Transplant Network and Japanese Liver Transplantation Society, identified risk factors for graft survival and compared the characteristics and graft survival in pDDLTs conducted before and after the introduction of the pediatric prioritization system.

RESULTS

Overall, 112 cases of pDDLT were included, with a 1-year graft survival rate of 86.6%. Four poor prognostic factors were identified: recipient intensive care unit stay, model for end-stage liver disease/pediatric end-stage liver disease score, donor cause of death, and donor total bilirubin. After the introduction of the system, allografts from pediatric donors were more reliably allocated to pediatric recipients and the annual number of pDDLTs increased. The 1-year graft survival rate improved significantly as did pDDLT conditions indicated by the risk factors.

CONCLUSIONS

Under the revised allocation system, opportunities for pDDLT increased, resulting in favorable recipient and donor conditions and improved survival.

A successful liver transplantation in a patient with neonatal-onset carbamoyl phosphate synthetase-1 deficiency

OBJECTIVES

Carbamoyl phosphate synthetase 1 (CPS-1) deficiency is a rare urea cycle disorder with an estimated prevalence of one in 150,000-200,000 live births. Patients often present with hyperammonemia shortly after protein feeding in the early days of life, and early-onset type is associated with high mortality rate.

CASE PRESENTATION

We present here a case of a newborn male with a history of two deceased siblings whose ammonium level exceeded 200 μmol/L on the first day after birth, and who was started on dextrose infusion and ammonia-scavenging therapy after oral feeding was discontinued. Peritoneal dialysis was initiated after the patient's ammonia level exceeded 500 μmol/L. At the age of five months, the patient underwent hemodialysis due to elevated ammonia levels accompanied by lethargy. The patient's ammonia levels were successfully brought under control, and the patient underwent a liver transplantation at the age of six month, donated by the father.

CONCLUSIONS

We present this case to emphasize the efficacy of liver transplantation from a parent carrying a CPS-1 deficiency. The authors believe that, with further support from future studies, the use of carglumic acid can improve the prognosis in the chronic management of CPS-1 deficiency.

Universal antifungal prophylaxis effectively prevents fungal bloodstream infection in pediatric liver transplant recipients: a retrospective real-world study

OBJECTIVES

Fungal bloodstream infection (fBSI) following pediatric liver transplantation presents a significant challenge; however, there remains a paucity of guidance regarding antifungal prophylaxis in this population. This study aimed to evaluate the effectiveness of universal antifungal prophylaxis and propose a desirable strategy.

METHODS

We enrolled 604 pediatric patients who underwent liver transplantation between 2020 and 2023, including 242 patients with empirical prophylaxis and 362 patients with universal prophylaxis. Univariate and multivariate logistic regression analyses were performed to identify independent factors for fBSI.

RESULTS

Eight (2.2%) pediatric recipients in the universal prophylaxis group and 13 (5.4%) in the empirical group developed fBSI (P = 0.038). Universal prophylaxis was a protective factor (P = 0.044), while high-volume intraoperative plasma transfusion and deceased donor liver transplantation were independent risk factors for fBSI (P = 0.035 and 0.008, respectively). Universal antifungal strategy showed an increased overall survival trend after liver transplantation although without significant statistical difference (P = 0.217). Patients with fBSI had poorer survival than those without fBSI (P <0.001).

CONCLUSIONS

Universal prophylaxis strategy for fBSI in pediatrics after liver transplantation is desirable as it could markedly decrease the occurrence of fBSI. Pediatric patients with deceased donors and high-volume intraoperative transfusion should be paid more attention to preventing fBSI.

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.

Outcomes of adult native liver survivors with biliary atresia: the current situation in Japan

PURPOSE

This study aimed to elucidate the difficulties faced by adult native liver survivors with biliary atresia (BA) in Japan.

METHODS

A single-center, retrospective, observational study of 57 adult patients with BA was conducted. The clinical course of BA was compared between native liver survivors and non-survivors who reached adulthood. Indications and outcomes of liver transplantation (LT) among non-survivors were assessed.

RESULTS

A significantly larger portion of non-survivors (n = 10) met the criteria for LT (p < 0.001) and received treatment for portal hypertension after reaching 20 years of age (p < 0.01) compared with the survivors. Causes of death included liver cirrhosis (n = 8), graft failure of living donor liver transplantation (LDLT) (n = 1), and hepatocarcinoma (n = 1). Two of the non-survivors who died of liver cirrhosis had no indication for LT because of alcohol dependence and uncontrolled infection. An appropriate donor candidate could not be found for the five patients who opted for LDLT. All six patients waitlisted for deceased donor liver transplantation (DDLT) died after a median waiting period of 17 months.

CONCLUSION

Adult BA patients in Japan have limited options for LT, mainly owing to low donor candidate availability for LDLT and a low prevalence of DDLT.

Evaluation of living donors for hereditary liver disease (siblings, heterozygotes)

Living donor liver transplantation (LDLT) is recognised as an alternative treatment modality to reduce waiting list mortality and expand the donor pool. Over recent decades, there have been an increasing number of reports on the use of LT and specifically LDLT for familial hereditary liver diseases. There are marginal indications and contraindications that should be considered for a living donor in paediatric parental LDLT. No mortality or morbidity related to recurrence of metabolic diseases has been observed with heterozygous donors, except for certain relevant cases, such as ornithine transcarbamylase deficiency, protein C deficiency, hypercholesterolemia, protoporphyria, and Alagille syndrome, while donor human leukocyte antigen homozygosity also poses a risk. It is not always essential to perform preoperative genetic assays for possible heterozygous carriers; however, genetic and enzymatic assays must hereafter be included in the parental donor selection criteria in the aforementioned circumstances.

Early allograft dysfunction in a pediatric liver allograft with an occult pathogenic mutation in the urea cycle

Liver transplantation risks transferring a genetic defect in metabolic pathways, including the urea cycle. We present a case of pediatric liver transplantation complicated by metabolic crisis and early allograft dysfunction (EAD) in a previously healthy unrelated deceased donor. Allograft function improved with supportive care, and retransplantation was avoided. Because hyperammonemia suggested an enzymatic defect in the allograft, genetic testing from donor-derived deoxyribonucleic acid revealed a heterozygous mutation in the ASL gene, which encodes the urea cycle enzyme argininosuccinate lyase. Homozygous ASL mutations precipitate metabolic crises during fasting or postoperative states, whereas heterozygous carriers retain sufficient enzyme activity and are asymptomatic. In the described case, postoperative ischemia/reperfusion injury created a metabolic demand that exceeded the enzymatic capacity of the allograft. To our knowledge, this is the first report of an acquired argininosuccinate lyase deficiency by liver transplantation and underscores the importance of considering occult metabolic variants in the allograft during EAD.