Beneficial effect of ursodeoxycholic acid in patients with acyl-CoA oxidase 2 (ACOX2) deficiency-associated hypertransaminasemia.

BACKGROUND AND AIMS: A variant (p.Arg225Trp) of peroxisomal acyl-CoA oxidase 2 (ACOX2), involved in bile acid (BA) side-chain shortening, has been associated with unexplained persistent hypertransaminasemia and accumulation of C27-BAs, mainly 3α,7α,12α-trihydroxy-5ß-cholestanoic acid (THCA). We aimed to investigate the prevalence of ACOX2 deficiency-associated hypertransaminasemia (ADAH), its response to ursodeoxycholic acid (UDCA), elucidate its pathophysiological mechanism and identify other inborn errors that could cause this alteration. METHODS AND RESULTS: Among 33 patients with unexplained hypertransaminasemia from 11 hospitals and 13 of their relatives, seven individuals with abnormally high C27-BA levels (>50% of total BAs) were identified by high-performance liquid chromatography-mass spectrometry. The p.Arg225Trp variant was found in homozygosity (exon amplification/sequencing) in two patients and three family members. Two additional nonrelated patients were heterozygous carriers of different alleles: c.673C>T (p.Arg225Trp) and c.456_459del (p.Thr154fs). In patients with ADAH, impaired liver expression of ACOX2, but not ACOX3, was found (immunohistochemistry). Treatment with UDCA normalized aminotransferase levels. Incubation of HuH-7 hepatoma cells with THCA, which was efficiently taken up, but not through BA transporters, increased reactive oxygen species production (flow cytometry), endoplasmic reticulum stress biomarkers (GRP78, CHOP, and XBP1-S/XBP1-U ratio), and BAXα expression (reverse transcription followed by quantitative polymerase chain reaction and immunoblot), whereas cell viability was decreased (tetrazolium salt-based cell viability test). THCA-induced cell toxicity was higher than that of major C24-BAs and was not prevented by UDCA. Fourteen predicted ACOX2 variants were generated (site-directed mutagenesis) and expressed in HuH-7 cells. Functional tests to determine their ability to metabolize THCA identified six with the potential to cause ADAH. CONCLUSIONS: Dysfunctional ACOX2 has been found in several patients with unexplained hypertransaminasemia. This condition can be accurately identified by a noninvasive diagnostic strategy based on plasma BA profiling and ACOX2 sequencing. Moreover, UDCA treatment can efficiently attenuate liver damage in these patients.

Delayed sequential abdominal wall closure in pediatric liver transplantation to overcome "large for size" scenarios.

BACKGROUND: Primary abdominal wall closure after pediatric liver transplantation (PLT) is neither always possible nor advisable, given the graft-recipient size discrepancy and its potential large-for-size scenario. Our objective was to report the experience accumulated with delayed sequential closure (DSC) guided by Doppler ultrasound control. METHODS: Retrospective analysis of DSC performed from 2013 to March 2020. RESULTS: Twenty-seven DSC (26.5%) were identified out of 102 PLT. Transplant indications and type of grafts were similar among both groups. In patients with DSC, mean weight and GRWR were 9.4 ± 5.5 kg (3.1-26 kg) and 4.7 ± 2.4 (1.9-9.7), significantly lower and higher than the primary closure cohort, respectively. The median time to achieve definitive closure was 6 days (range 3-23 days), and the median number of procedures was 4 (range 2-9). Patients with DSC had longer overall PICU (22.5 ± 16.9 vs. 9.1 ± 9.7 days, p < .05) and hospital stay (33.4 ± 19.1 vs 23, 9 ± 19.8 days (p < .05). These differences are less remarkable if the analysis is performed in a subgroup of patients weighing less than 10 kg. Two patients presented vascular complications (7.4%) within DSC group. No differences were seen when comparing overall, 3-year graft and patient survival (96% and 96% in the DSC group). CONCLUSIONS: DSC is a simple and safe technique to ensure satisfactory clinical outcomes to overcome "large for size" scenarios in PLT. In addition, we were able to avoid using a permanent biological material for closing the abdomen.

Epstein-Barr virus-associated risk factors for post-transplant lymphoproliferative disease in pediatric liver transplant recipients.

BACKGROUND: Post-transplant lymphoproliferative disorder (PTLD) are the most common de novo malignancies after liver transplantation (LT) in children. The aim of our study was to assess the role of pre-LT EBV status and post-LT EBV viral load as risk factors for developing PTLD in a cohort of pediatric LT recipients. METHODS: Data of all children who underwent LT between January 2002 and December 2019 were collected. Two cohorts were built EBV pre-LT primary infected cohort and EBV post-LT primary infected cohort. Moreover, using the maximal EBV viral load, a ROC curve was constructed to find a cutoff point for the diagnosis of PTLD. RESULTS: Among the 251 patients included in the study, fifteen PTLD episodes in 14 LT recipients were detected (2 plasmacytic hyperplasia, 10 polymorphic PTLD, 2 monomorphic PTLD, and 1 Classical-Hodgkin's lymphoma). Patients of the EBV post-LT primary infected cohort were 17.1 times more likely to develop a PTLD than patients of the EBV pre-LT primary infected cohort (2.2-133.5). The EBV viral load value to predict PTLD was set at 211 000 UI/mL (93.3% sensitivity and 77.1% specificity; AUC 93.8%; IC 0.89-0.98). In EBV post-LT primary infected cohort, patients with a viral load above 211 000 were 30 times more likely to develop PTLD than patients with a viral load below this value (OR 29.8; 3.7-241.1; p < 0.001). CONCLUSIONS: The combination of pretransplant EBV serological status with EBV post-transplant viral load could be a powerful tool to stratify the risk of PTLD in pediatric LT patients.

Endoscopic variceal ligation as primary prophylaxis for upper GI bleeding in children.

BACKGROUND AND AIMS: Variceal hemorrhage can be a life-threatening adverse event of chronic liver disease. In contrast to the well-described guidelines for the management of portal hypertension (PH) in adults, there is limited evidence about the optimal prophylactic management of variceal bleeding in children. This study was carried out to assess the efficacy of endoscopic variceal ligation (EVL) as primary prophylaxis to prevent upper GI bleeding in children with PH. METHODS: From January 2014 to April 2018, all pediatric patients with PH disease and medium to large esophageal varices or reddish spots, regardless of the grade of the varix, were prospectively included in the protocol of primary prophylaxis with EVL. A second retrospective group of patients was made after reviewing medical records of 32 pediatric patients with PH that presented esophageal varices in the upper endoscopy and had received propranolol as primary prophylaxis. RESULTS: Twenty-four patients (75%) reached varices eradication in the EVL group, with a median of 2 procedures (range, 1-4) before eradication and a median time to eradication of 3.40 months (range, 1.10-13.33). No EVL-related adverse events were observed. Statistically significant differences were observed in the bleeding rate at 3 years between propranolol and EVL groups (6/32 [21.9%] vs 1/32 [3.2%], P < .02). The hazard ratio for bleeding for patients treated with propranolol compared with those treated with EVL was 2.6 (95% confidence interval, 1.53-3.67). CONCLUSIONS: EVL is a safe and effective treatment to prevent upper GI bleeding in pediatric patients with PH. (Clinical trial registration number: NCT03943784.).

Endotipsitis as an indication for pediatric liver transplantation.

Endotipsitis is a rare but severe complication of transjugular intrahepatic portosystemic shunt (TIPS), a device widely used to treat portal hypertension in adults, but sparsely used in children. We report a case of endotipsitis in a 3-year-old child affected of biliary atresia. She underwent a Kasai procedure at 3 months of age but, although the bile flow was restored, she presented upper gastrointestinal bleeding due to portal hypertension 1.5 years later. A TIPS was placed in order to control the hemorrhage. A year after TIPS placement, she started presenting repeated episodes of cholangitis. Blood cultures were positive to Enterobacter cloacae. Even with long antibiotic courses, adjusted to blood cultures, infectious signs were observed after antibiotic withdrawal. Device infection was demonstrated through Positron emission tomography-Computed tomography scan. The patient was listed for liver transplantation, and intravenous antibiotic treatment was maintained until stent removal during the liver transplant 8 months later. No infectious complications were demonstrated after the surgery. To the best of our knowledge, this is the first case report of endotipsitis described in a pediatric patient.

The Role of Liver Transplantation in Propionic Acidemia.

Despite optimal medical treatment and strict low-protein diet, the prognosis of propionic acidemia (PA) patients is generally poor. We aim to report our experience with liver transplantation (LT) in the management of PA patients. Six patients with PA received a LT at a mean age of 5.2 years (1.3-7.5 years). The indications for LT were frequent metabolic decompensations in the first 4 patients and preventative in the last 2 patients. Two patients presented hepatic artery thromboses that were solved through an interventional radiologist approach. These patients showed a very high procoagulant state that was observed by thromboelastography. Arterial vasospasm without thrombus was observed in 2 patients during the LT surgery. In order to avoid hepatic artery thrombosis, an arterial conduit from the recipient aorta to the hepatic artery of the donor was used in the fifth patient. After LT, patients presented improvement in propionyl byproducts without complete normalization, but no decompensations have been observed. In conclusion, LT could be a good therapeutic option to improve the metabolic control and the quality of life of PA patients. Improved surgical strategies along with new techniques of interventional radiology allow us to perform the LT minimizing the complications derived from the higher risk of hepatic artery thrombosis.

Role of Biodegradable Stents as Part of Treatment of Biliary Strictures after Pediatric and Adult Liver Transplantation: An Observational Single-Center Study.

This brief report presents the results of 20 adult and pediatric patients treated with the use of biodegradable SX-Ella biliary stents placed by means of a transhepatic approach for the treatment of benign biliary strictures after liver transplantation. Stent insertions were always feasible (100%), and only 1 case of acute pancreatitis was observed (5%). The overall clinical success rate of the procedure, including anastomotic and nonanastomotic strictures, was 75%, and was higher in the anastomotic stricture group (81.25%) than in the nonanastomotic stricture group (50%).

Conversion from twice-daily to once-daily tacrolimus formulation in pediatric liver transplant recipients - a long-term prospective study.

To assess the safety and efficacy of conversion from twice-daily tacrolimus to once-daily tacrolimus in pediatric liver transplant recipients. Conversion from twice-daily to once-daily tacrolimus was made in stable pediatric liver transplant recipients. Doses and serum levels of tacrolimus, liver, and renal function were recorded on the day before the conversion and at days 5, 30, 90, and 180 postconversion. Patients were controlled every 2-3 months thereafter. Fifty-five patients were enrolled in the study. The mean age at conversion was 10.2 ± 3.6 years. The mean tacrolimus trough level was 4.7 ± 1.9 ng/dl preconversion, followed by a significant decline to 4.2 ± 1.7 30 days after the switch (P < 0.004). Mean daily tacrolimus dose was 0.09 ± 0.046 mg/Kg preconversion with a significant increase to 0.11 ± 0.060 3 months postconversion (P < 0.001). Fifteen patients with calculated glomerular filtration rate between 60 to 80 ml/min/m2 preconversion showed a significant improvement one and 3 years after the switch (73 ± 4.1, 83 ± 4.3 and 90.3 ± 7.3 ml/min/m2 , respectively (P < 0.001). The mean follow-up was 5.2 ± 2.4 years. Conversion to once-daily tacrolimus is safe and effective in a cohort of stable pediatric liver transplant patients.

Successful long-term outcome of pediatric liver-kidney transplantation: a single-center study.

INTRODUCTION: Liver-kidney transplantation is a rare procedure in children, with just ten to 30 cases performed annually worldwide. The main indications are autosomal recessive polycystic liver-kidney disease and primary hyperoxaluria. This study aimed to report outcomes of liver-kidney transplantation in a cohort of pediatric patients. METHODS: We retrospectively analyzed all pediatric liver-kidney transplantations performed in our center between September 2000 and August 2015. Patient data were obtained by reviewing inpatient and outpatient medical records and our transplant database. RESULTS: A total of 14 liver-kidney transplants were performed during the study period, with a median patient age and weight at transplant of 144.4 months (131.0-147.7) and 27.3 kg (12.0-45.1), respectively. The indications for liver-kidney transplants were autosomal recessive polycystic liver-kidney disease (8/14), primary hyperoxaluria -1 (5/14), and idiopathic portal hypertension with end-stage renal disease (1/14). Median time on waiting list was 8.5 months (5.7-17.3). All but two liver-kidney transplants were performed simultaneously. Patients with primary hyperoxaluria-1 tended to present a delayed recovery of renal function compared with patients transplanted for other indications (62.5 vs 6.5 days, respectively, P 0.076). Patients with liver-kidney transplants tended to present a lower risk of acute kidney rejection than patients transplanted with an isolated kidney transplant (7.2% vs 32.7%, respectively; P < 0.07). Patient and graft survival at 1, 3, and 5 years were 100%, 91.7%, 91.7%, and 91.7%, 83.3%, 83.3%, respectively. No other grafts were lost. CONCLUSION: Long-term results of liver-kidney transplants in children are encouraging, being comparable with those obtained in isolated liver transplantation.

Impact of Liver Inflammation on Bile Acid Side Chain Shortening and Amidation.

Bile acid (BA) synthesis from cholesterol by hepatocytes is inhibited by inflammatory cytokines. Whether liver inflammation also affects BA side chain shortening and conjugation was investigated. In human liver cell lines (IHH, HepG2, and HepaRG), agonists of nuclear receptors including the farnesoid X receptor (FXR), liver X receptor (LXR), and peroxisome proliferator-activated receptors (PPARs) did not affect the expression of BA-related peroxisomal enzymes. In contrast, hepatocyte nuclear factor 4α (HNF4α) inhibition down-regulated acyl-CoA oxidase 2 (ACOX2). ACOX2 was repressed by fibroblast growth factor 19 (FGF19), which was prevented by extracellular signal-regulated kinase (ERK) pathway inhibition. These changes were paralleled by altered BA synthesis (HPLC-MS/MS). Cytokines able to down-regulate cholesterol-7α-hydroxylase (CYP7A1) had little effect on peroxisomal enzymes involved in BA synthesis except for ACOX2 and bile acid-CoA:amino acid N-acyltransferase (BAAT), which were down-regulated, mainly by oncostatin M (OSM). This effect was prevented by Janus kinase (JAK) inhibition, which restored BA side chain shortening and conjugation. The binding of OSM to the extracellular matrix accounted for a persistent effect after culture medium replacement. In silico analysis of four databases (n = 201) and a validation cohort (n = 90) revealed an inverse relationship between liver inflammation and ACOX2/BAAT expression which was associated with changes in HNF4α levels. In conclusion, BA side chain shortening and conjugation are inhibited by inflammatory effectors. However, other mechanisms involved in BA homeostasis counterbalance any significant impact on the serum BA profile.

Transition to Adult Care for Pediatric Liver Transplant Recipients.

In recent years a growing number of pediatric liver transplant recipients are reaching adulthood and are transferred to an adult team. Because pediatric to adult transition has become a common event with many particularities, specific clinical protocols are needed to guide professionals in this process. Transition must be seen as a complex process of high vulnerability for the patient. The incorrect assumption that the transition process is only a bureaucratic transfer of information leads to inappropriate transition procedures that result in young patients not ready to move to adult units with guaranteed success. To ensure this success, a correct coordination and transmission of the information, accompaniment by the health professional during the whole process, and the empowerment of the patient are required. To have a successful transition, a person within the pediatric team must be in charge of the process (named worker).

Successful Treatment with Rituximab and Immunoadsorption for an Auto-Antibody Induced Bile Salt Export Pump Deficiency in a Liver Transplanted Patient.

We present an 8 years old girl who was diagnosed at 6 months of age of Progressive Familial Intrahepatic Cholestasis type 2. Although liver transplantation (LT) was classically considered curative for these patients, cholestasis recurrence with normal gamma-glutamyl transpeptidase (GGT), mediated by anti-bile salt export pump (BSEP) antibodies after LT (auto-antibody Induced BSEP Deficiency, AIBD) has been recently reported. Our patient underwent LT at 14 months. During her evolution, patient presented three episodes of acute rejection. Seven years after the LT, the patient presented pruritus with cholestasis and elevation of liver enzymes with persistent normal GGT. Liver biopsy showed intrahepatic cholestasis and giant-cell transformation with very low BSEP activity. Auto-antibodies against BSEP were detected therefore an AIBD was diagnosed. She was treated with Rituximab and immunoadsorption with resolution of the AIBD. As a complication of the treatment she developed a pneumocystis infection successfully treated with corticoids, cotrimoxazol and anidulafungin.

[Ledipasvir/sofosbuvir combination for chronic hepatitis C infection in children and adolescents]. / Combinación de ledipasvir/sofosbuvir como tratamiento de la infección crónica por hepatitis C.

INTRODUCTION: Hepatitis C virus infection is world health problem. The aim of this study was to assess the safety and efficacy of ledipasvir/sofosbuvir combination in chronic Hepatitis C Virus (HCV) genotype 1 and 4 infection in paediatric patients. METHODS: Eligible patients to be treated with ledipasvir/sofosbuvir were patients from 6 to 18 years old with a chronic HCV genotype 1 or 4 infection. The duration and doses of antiviral drugs were changed depending on patient age, fibrosis stage, and PEGylated interferon+ribavirin experience status. The primary efficacy endpoint was the percentage of patients with a sustained virological response 12 weeks post-treatment. RESULTS: A total of nine patients (7 males) with a median age of 14.8 years (8.48-17.91) were treated with ledipasvir/sofosbuvir combination. Five patients received previous treatment with PEGylated interferon+ribavirin during a median of 8.5 months (3-12 months). Eight patients had some degree of fibrosis (1 patient presented with F1, three patients F2, 2 patients F3, and 2 patients F4). The median pre-treatment viral load was 6.2 Log [5.9-6.8] with the HCV RNA becoming negative six weeks after starting the treatment in 100% of the patients. All patients maintained a sustained viral response at 12 weeks. Three patients (33.3%) had some type of adverse effect (2 headache and one oral thrush). The median post-treatment follow-up was 24 weeks (12-104). CONCLUSIONS: Treatment with ledipasvir/sofosbuvir in paediatric patients with chronic HCV infection genotype 1 and 4 is safe and effective with SVR12 and similar to those reported in adults.