Too late to say it is too early--how to get children with non-cirrhotic metabolic diseases transplanted at the right time?

Crigler-Najjar syndrome: looking to the future does not make us forget the present

Recently, the safety and efficacy of gene therapy were evaluated in patients with Crigler-Najjar syndrome (CNS). Although it is a promising curative option for CNS, many doubts still persist about its long-term efficacy and safety. Furthermore, there is a risk of overlooking several unresolved problems still present in current clinical practice. This letter is a call for action on crucial open issues that remain nowadays an unmet need in the management of CNS patients.

The impact of liver transplantation on health-related quality of life in (acute) intoxication-type inborn errors of metabolism

Organic acidurias (OAs), urea-cycle disorders (UCDs), and maple syrup urine disease (MSUD) belong to the category of intoxication-type inborn errors of metabolism (IT-IEM). Liver transplantation (LTx) is increasingly utilized in IT-IEM. However, its impact has been mainly focused on clinical outcome measures and rarely on health-related quality of life (HRQoL). Aim of the study was to investigate the impact of LTx on HrQoL in IT-IEMs. This single center prospective study involved 32 patients (15 OA, 11 UCD, 6 MSUD; median age at LTx 3.0 years, range 0.8-26.0). HRQoL was assessed pre/post transplantation by PedsQL-General Module 4.0 and by MetabQoL 1.0, a specifically designed tool for IT-IEM. PedsQL highlighted significant post-LTx improvements in total and physical functioning in both patients' and parents' scores. According to age at transplantation (≤3 vs. >3 years), younger patients showed higher post-LTx scores on Physical (p = 0.03), Social (p < 0.001), and Total (p =0.007) functioning. MetabQoL confirmed significant post-LTx changes in Total and Physical functioning in both patients and parents scores (p ≤ 0.009). Differently from PedsQL, MetabQoL Mental (patients p = 0.013, parents p = 0.03) and Social scores (patients p = 0.02, parents p = 0.012) were significantly higher post-LTx. Significant improvements (p = 0.001-0.04) were also detected both in self- and proxy-reports for almost all MetabQoL subscales. This study shows the importance of assessing the impact of transplantation on HrQoL, a meaningful outcome reflecting patients' wellbeing. LTx is associated with significant improvements of HrQol in both self- and parent-reports. The comparison between PedsQL-GM and MetabQoL highlighted that MetabQoL demonstrated higher sensitivity in the assessment of disease-specific domains than the generic PedsQL tool.

Evolving Trends in Liver Transplant for Metabolic Liver Disease in the United States

Indications for liver transplantation (LT) in metabolic disease are evolving. We reviewed the US experience with primary LT for metabolic disease in the Scientific Registry for Transplant Recipients (October 1987 to June 2017) to determine the following: temporal changes in indications, longterm outcomes, and factors predicting survival. Patients were grouped by the presence of structural liver disease (SLD) and whether the defect was confined to the liver. There were 5996 patients who underwent LT for metabolic disease, 2354 (39.3%) being children. LT for metabolic disease increased in children but not in adults. Children experienced a 6-fold increase in LT for metabolic disease without SLD. Indications for LT remained stable in adults. Living donor liver transplantation increased between era 1 and era 3 from 5.6% to 7.6% in children and 0% to 4.5% in adults. Patient and graft survival improved with time. The latest 5-year patient survival rates were 94.5% and 81.5% in children and adults, respectively. Outcomes were worse in adults and in those with extrahepatic disease (P < 0.01), whereas SLD did not affect outcomes. Survival improved with younger age at LT until age <2 years. On multivariate analysis, diagnostic category, inpatient status, age at LT, and transplant era significantly predicted outcomes in all ages with male sex predicting survival in childhood only. Children without structural disease were less likely to die awaiting LT and had improved post-LT survival compared with children with chronic liver disease. In conclusion, LT for metabolic disease is increasingly used for phenotypic correction in children; extrahepatic manifestations significantly impact survival at all ages; where indicated, transplantation should not be unnecessarily delayed; and the development of new allocation models may be required.

Liver transplantation for homozygote familial hypercholesterolemia: the only curative treatment

FH is an autosomal dominant genetic disorder characterized by increased TC and LDL level, which leads to xanthomas, atherosclerosis, and cardiac complications even in childhood. The treatment options are diet, medical treatment, lipid apheresis, and LT. The aim of our study was to analyze our data of patients with FH. Between 2004 and 2015, there were 51 patients who underwent pediatric LT at our center. All patients with FH were identified, and the data were retrospectively analyzed. There were eight patients with homozygous FH in the median age of 10 years (IQR 6-12) who underwent LT. The median pre-operative TC and LDL levels were 611 mg/dL (IQR: 460-844) and 574 mg/dL (IQR: 398-728) and decreased to normal levels 1 week after LT (TC: 193 mg/dL and LDL: 141 mg/dL). Two patients died two and 18 months after LT due to sudden cardiac arrest. Both patients were diagnosed with cardiovascular disease pre-operatively. The LT is the only curative treatment for this disease. To achieve an excellent outcome, it should be performed before the development of cardiovascular disease, because the regression of severe cardiovascular disease after transplantation is limited.

Liver transplant in ethylmalonic encephalopathy: a new treatment for an otherwise fatal disease

Ethylmalonic encephalopathy is a fatal, rapidly progressive mitochondrial disorder caused by ETHE1 mutations, whose peculiar clinical and biochemical features are due to the toxic accumulation of hydrogen sulphide and of its metabolites, including thiosulphate. In mice with ethylmalonic encephalopathy, liver-targeted adeno-associated virus-mediated ETHE1 gene transfer dramatically improved both clinical course and metabolic abnormalities. Reasoning that the same achievement could be accomplished by liver transplantation, we performed living donor-liver transplantation in an infant with ethylmalonic encephalopathy. Unlike the invariably progressive deterioration of the disease, 8 months after liver transplantation, we observed striking neurological improvement with remarkable achievements in psychomotor development, along with dramatic reversion of biochemical abnormalities. These results clearly indicate that liver transplantation is a viable therapeutic option for ETHE1 disease.

Early Liver Transplantation for Neonatal-Onset Methylmalonic Acidemia

With conventional dietary treatment, the clinical course of methylmalonic acidemia due to cobalamin-unresponsive methylmalonyl-CoA mutase (MCM) deficiency is characterized by the persistent risk of recurrent life-threatening decompensation episodes with metabolic acidosis, hyperammonemia, and coma. Liver transplant has been proposed as an alternative treatment and anecdotally attempted in the last 2 decades with inconsistent results. Most criticisms of this approach have been directed at the continuing risk of neurologic and renal damage after transplant. Here, we report the perioperative and postoperative clinical and biochemical outcomes of 2 patients with severe MCM deficiency who underwent early liver transplant. In both cases, liver transplant allowed prevention of decompensation episodes, normalization of dietary protein intake, and a marked improvement of quality of life. No serious complications have been observed at 12 years' and 2 years' follow-up, respectively, except for mild kidney function impairment in the older patient. On the basis of our experience, we strongly suggest that liver transplant should be offered as a therapeutic option for children with cobalamin-unresponsive MCM deficiency at an early stage of the disease.

Liver, pancreas and small bowel transplantation: current ethical issues

We describe the medical state of the art in liver, pancreas and small bowel transplantation, and portray the ethical issues. Although most ethical questions related to these transplantations are not specific for liver, pancreas and small bowel, they do challenge ethical analysis as well as new policies and clinical procedures. Firstly, outcomes continue to be of utmost concern, as information is only limited available, is developing over time and is surrounded by many uncertainties. Secondly, characteristics of donors and recipients should be carefully evaluated. The question of what qualifies a donor and a recipient should be considered against the background of a quest for extended criteria, embracing marginal cases, and a judgment with regard to what counts as a good enough outcome. Thirdly, ethical principles of autonomy and fairness are pushed, given the circumstance of severe scarcity, towards limits that can easily be crossed.