Early steroids after pediatric liver transplantation protect against T-cell-mediated rejection: Results from the ChilSFree study

Steroid-free immunosuppression protocols gained popularity in pediatric liver transplantation (pLT) after the introduction of IL-2-receptor blockade for induction therapy. We analyzed the clinical and immunologic outcome data of the multicenter prospective observational ChilSFree study to compare the impact of steroid-free versus steroid-containing immunosuppressive therapy following pLT in a real-life scenario. Two hundred forty-six children [55.3% male, age at pLT median: 2.4 (range: 0.2-17.9) y] transplanted for biliary atresia (43%), metabolic liver disease (9%), acute liver failure (4%), hepatoblastoma (9%), and other chronic end-stage liver diseases (39%) underwent immune monitoring and clinical data documentation over the first year after pLT. Patient and graft survival at 1 year was 98.0% and 92.7%, respectively. Primary immunosuppression was basiliximab induction followed by tacrolimus (Tac) monotherapy (55%), Tac plus steroid tapering over 3 months (29%), or cyclosporine and steroid tapering (7%). One center used intraoperative steroids instead of basiliximab followed by Tac plus mycophenolate mofetil (7% of patients). N = 124 biopsy-proven T-cell-mediated rejections were documented in n = 82 (33.3%) patients. T-cell-mediated rejection occurred early (median: 41 d, range: 3-366 d) after pLT. Patients initially treated with Tac plus steroids experienced significantly fewer episodes of rejection than patients treated with Tac alone (chi-square p <0.01). The use of steroids was associated with earlier downregulation of proinflammatory cytokines interferon (IFN)-γ, Interleukin (IL)-6, CX motif chemokin ligand (CXCL)8, IL-7, and IL-12p70. Both primary immunosuppression with Tac plus steroids and living donor liver transplantation were independent predictors of rejection-free survival 1 year after pLT on logistic regression analysis. Adjunctive steroid therapy after pLT leads to earlier suppression of the post-pLT proinflammatory response and significantly reduced rejection rates during the first year after pLT (15.9%). Fifty-one percent of patients initially treated without steroids remain steroid-free over the first 12 months without rejection.

Native liver survival in bile salt export pump deficiency: results of a retrospective cohort study

BACKGROUND

Bile salt export pump (ABCB11) deficiency [Progressive familial intrahepatic cholestasis (PFIC2)] is the most common genetic cause of PFIC and is associated with pruritus and progressive liver disease. Surgical biliary diversion or pharmacological [ileal bile acid transporter inhibitor (IBATi)] approaches can be used to block the recirculation of bile acids to the liver. There is a paucity of detailed data on the natural history and, in particular, the longitudinal evolution of bile acid levels to predict treatment response. Cross-sectional data from large international consortia suggested a maximum cutoff value of bile acids after the intervention to predict a successful outcome.

METHODS

This retrospective, single-center, cohort study included all patients with confirmed biallelic pathogenic ABCB11 genotype PFIC2 treated at our institution with ≥2 years follow-up. The outcomes of interventions and predictors of long-term health were analyzed.

RESULTS

Forty-eight cases were identified with PFIC2. Eighteen received partial external biliary diversion (PEBD) surgery, and 22 patients underwent liver transplantation. Two patients developed HCC and 2 died. Improved survival with native liver was closely associated with genotype, complete normalization of serum bile acids following PEBD, and alleviation of pruritus. Persistence of mild-to-moderate elevation of bile acids or a secondary rise following normalization was associated with liver disease progression and led to transplantation, suggesting that any prolonged elevation of bile acids worsens the chance of native liver survival. Higher-grade fibrosis at the time of PEBD was not associated with reduced long-term native liver survival. Patients with PFIC2 benefit from PEBD even at a stage of advanced fibrosis.

CONCLUSION

Serum bile acid levels are an early predictor of treatment response and might serve as the gold standard in the evaluation of novel therapies including IBATi.

The Impact of Male Gender and Thrombophilia on Disease Progression in Children with Biliary Atresia—A Single-Centre Cohort Study

Epidemiological evidence suggests that thrombophilic factors, including male sex, non-O blood type, MTHFRnt677TT mutation, factor V Leiden G1691A mutation, and prothrombin G20210A polymorphism, may contribute to the progression of fibrosis and occurrence of portal vein thrombosis in liver disease. We retrospectively investigated the effect of potentially thrombophilic factors on native liver survival as a patient-relevant endpoint of disease progression in a cohort of 142 children being followed up for biliary atresia at Hannover Medical School from April 2017 to October 2019. No significant association could be determined. There was no evidence for relevant differences in native liver survival for the Factor V Leiden G1691A mutation (hazard ratio [HR] = 0.86, 95% confidence interval [CI] 0.38–1.98, p = 0.73), prothrombin G20210A polymorphism (HR = 0.96, 95%CI 0.24–3.65, p = 0.96), non-O blood type (HR = 0.79, 95%CI 0.51–1.21, p = 0.28) or MTHFRnt677TT mutation (HR = 1.24, 95%CI 0.60–2.56, p = 0.56). A certain, albeit not strong, evidence of reduced native liver survival in male patients after Kasai hepatoportoenterostomy, particularly during the first 2000 days (42%; HR = 1.41, 95%CI 0.92–2.18, p = 0.11) was found. All children with pre-transplant portal vein thrombosis (n = 7) had non-O blood types. Larger multi-centre studies are necessary to show if the male sex or other thrombophilic factors could be potentially associated with reduced native liver survival.

Diagnosing Acute Cellular Rejection after Paediatric Liver Transplantation-Is There Room for Interleukin Profiles?

BACKGROUND

The current gold standard to diagnose T-cell-mediated acute rejection (TCMR) requires liver histology. Using data from the ChilSFree study on immune response after paediatric liver transplantation (pLT), we aimed to assess whether soluble cytokines can serve as an alternative diagnostic tool in children suspected to have TCMR.

METHODS

A total of n = 53 blood samples obtained on the day of or up to 3 days before liver biopsy performed for suspected TCMR at median 18 days (range 7-427) after pLT in n = 50 children (38% female, age at pLT 1.8 (0.5-17.5) years) were analysed for circulating cytokine levels using Luminex-based Multiplex technology. Diagnostic accuracy of cytokine concentrations was assessed using a multivariable model based on elastic net regression and gradient boosting machine analysis.

RESULTS

TCMR was present in 68% of biopsies. There was strong evidence that patients with TCMR had increased levels of soluble CXCL8, CXCL9, CXCL10, IL-16, IL-18, HGF, CCL4, MIF, SCGF-β, and HGF before biopsy. There was some evidence for increased levels of sCD25, ICAM-1, IL-6, IL-3, and CCL11. Diagnostic value of both single cytokine levels and a combination of cytokines and clinical markers was poor, with AUROCs not exceeding 0.7.

CONCLUSION

Patients with TCMR showed raised levels of cytokines and chemokines reflective of T-cell activation and chemotaxis. Despite giving insight into the mechanisms of TCMR, the diagnostic value of soluble cytokines for the confirmation of TCMR in a clinical scenario of suspected TCMR is poor.

Telomere length is associated with intima-media thickness in pediatric liver transplant patients: A prospective cohort study

Leukocyte telomere length (LTL) is a marker for biological age. Pediatric liver transplant recipients show a high rate of subclinical atherosclerosis, indicated by elevated intima-media thickness (IMT). We hypothesized that atherosclerosis is associated with biological age in these patients and investigated the course of LTL over time. We measured LTL from peripheral blood leukocytes by quantitative polymerase chain reaction and IMT from 97 pediatric patients after liver transplantation in a prospective cohort study. Of the patients, 71% (n = 69) had two or more assessments (total, 228 observations; median follow-up, 1.1 years). Lower LTL was associated with higher IMT (β = -0.701, p = 0.01) and higher aspartate aminotransferase (β = -0.001, p = 0.02), adjusted for age, sex, and age at transplantation. Of the patients, 45% showed decreasing LTL over time, whereas 55% exhibited stable LTL. Patients with stable LTL showed a decrease in IMT (median, -0.02 mm/year) and a decrease of tacrolimus trough levels (median, -0.08 μg/L/year). LTL is associated with IMT independent of age in pediatric liver transplant patients, suggesting that early aging contributes to the high burden of subclinical cardiovascular damage and may furthermore negatively affect the graft.

Recipient-Specific Risk Factors Impairing Patient and Graft Outcome after Pediatric Liver Transplantation-Analysis of 858 Transplantations in 38 Years

(1) Background and Aim: Despite excellent long-term results in pediatric liver transplantation (pLTx), mortality and graft loss still are to be diminished. We aim to describe time-dependent changes and long-term outcome of a large single-center pLTx cohort and to identify independent recipient-related risk factors impairing patient and graft survival. (2) Methods: This is a retrospective single-center study analyzing all pediatric liver transplants from 1983–2020. Risk factors for mortality and graft loss were identified by univariable and multi-linear regression analysis. (3) Results: We analyzed 858 liver transplantations in 705 pediatric patients. Five-year patient/graft survival increased from 60.9%/48.0% (1983–1992) to 97.5%/86.5% (OR = 12.5; p < 0.0001/OR = 6.5; p < 0.0001) (2014–2020). Indications changed significantly over time, with a higher proportion of patients being transplanted for malignancies and metabolic disease and indications of PFIC and α1AT-deficiency declining. The era of transplantation (log7.378/9.657; p < 0.0001) and indication of acute liver failure (log = 1.944/2.667; HR = 2.015/1.772; p = 0.0114/0.002) impairs patient/graft survival significantly in the multivariate analysis. Furthermore, patient survival is worsened by re-transplantation (log = 1.755; HR = 1.744; p = 0.0176) and prolonged waiting times in high-urgency status (log = 2.588; HR = 1.073; p = 0.0026), whereas the indication of biliary atresia improved outcome (log = 1.502; HR = 0.575; p = 0.0315). Graft survival was additionally impaired by pre-existing portal vein thrombosis (log = 1.482; HR = 2.016; p = 0.0330). (4) Conclusions: Despite more complex indications, patient and graft survival after pLTx continue to improve.. Acute liver failure remains the indication with poorest outcome, and listing for high urgency liver transplantation should be considered carefully and early to keep waiting time on HU list short. Furthermore, pre-transplant portal vein thrombosis should be prevented whenever possible to improve graft survival.

Identification of Impaired Executive Functioning after Pediatric Liver Transplantation Using Two Short and Easily Applicable Tests: Cognitive Functioning Module PedsQL and Children's Color Trail Test

We aimed to assess executive functioning in children after liver transplantation compared with healthy controls and in relation to real-life school performance using the PedsQL^TM Cognitive Functioning Scale (CogPedsQL) and the Childrens’ Color Trail Test (CCTT). One hundred and fifty five children (78f, median age 10.4 (1.2–18.3) years) underwent testing with CogPedsQL and/or CCTT 4.9 (0.1–17.0) years after transplantation. Results were compared to those of 296 healthy children (165f, median age 10.0 (2.0–18.0) years). Liver transplanted children displayed significantly reduced scores for cogPedsQL and CCTT1&2 compared to healthy controls. Overall, school performance was lower in patients compared to controls. In both patients and controls, results of CCTT2 and CogPedsQL correlated strongly with school performance. In contrast to controls, school performance in patients correlated with the level of maternal but not paternal primary education degree (r = −0.21, p = 0.03). None of the patient CCTT or CogPedsQL test results correlated with parental school education. Conclusion: CogPedsQL and CCTT 1&2 were easily applicable in children after OLT and revealed reduced executive functioning compared to controls. Results reflect real life school performance. The association of parental education with school performance is reduced in transplanted children, which possibly indicates the overriding impact of transplant-associated morbidity on cognitive outcomes.

Current Evidence on the Clinical Relevance of Donor-specific Antibodies in Paediatric Liver Transplantation

ABSTRACT

The clinical impact of donor-specific antibodies (DSA) occurring before or after liver transplantation (LT) against donor-human leucocyte antigen (HLA) on graft outcome is still unclear. We aim to present the current consensus based on recent paediatric LT case series. Compared to kidney transplantation, the liver seems to be less susceptible to antibody-mediated graft damage, which is likely due to protective Kupffer cell activity. The incidence of DSA after liver transplantation is higher in children than in adults. DSA directed against HLA class II molecules, mainly DQ, occur more often. The presence of such anti-class II DSA (DQ/DR), especially of the complement-binding IgG3 subclass, may be associated with endothelial injury, T-cell-mediated rejection (TCMR), inflammation, and fibrosis. Regular DSA-posttransplant monitoring cannot as yet be recommended in routine practice but may be useful in selected cases.

ERNICA Consensus Conference on the Management of Patients with Long-Gap Esophageal Atresia: Perioperative, Surgical, and Long-Term Management

INTRODUCTION

 Evidence supporting best practice for long-gap esophageal atresia is limited. The European Reference Network for Rare Inherited Congenital Anomalies (ERNICA) organized a consensus conference on the management of patients with long-gap esophageal atresia based on expert opinion referring to the latest literature aiming to provide clear and uniform statements in this respect.

MATERIALS AND METHODS

 Twenty-four ERNICA representatives from nine European countries participated. The conference was prepared by item generation, item prioritization by online survey, formulation of a final list containing items on perioperative, surgical, and long-term management, and literature review. The 2-day conference was held in Berlin in November 2019. Anonymous voting was conducted via an internet-based system using a 1 to 9 scale. Consensus was defined as ≥75% of those voting scoring 6 to 9.

RESULTS

 Ninety-seven items were generated. Complete consensus (100%) was achieved on 56 items (58%), e.g., avoidance of a cervical esophagostomy, promotion of sham feeding, details of delayed anastomosis, thoracoscopic pouch mobilization and placement of traction sutures as novel technique, replacement techniques, and follow-up. Consensus ≥75% was achieved on 90 items (93%), e.g., definition of long gap, routine pyloroplasty in gastric transposition, and avoidance of preoperative bougienage to enable delayed anastomosis. Nineteen items (20%), e.g., methods of gap measurement were discussed controversially (range 1-9).

CONCLUSION

 This is the first consensus conference on the perioperative, surgical, and long-term management of patients with long-gap esophageal atresia. Substantial statements regarding esophageal reconstruction or replacement and follow-up were formulated which may contribute to improve patient care.

Normal liver stiffness and influencing factors in healthy children: An individual participant data meta-analysis

BACKGROUND & AIMS

Although transient elastography (TE) is used to determine liver stiffness as a surrogate to hepatic fibrosis, the normal range in children is not well defined. We performed a systematic review and individual participant data (IPD) meta-analysis to determine the range of liver stiffness in healthy children and evaluate the influence of important biological parameters.

METHODS

We pooled data from 10 studies that examined healthy children using TE. We divided 1702 children into two groups: ≥3 years (older group) and < 3 years of age (younger group). Univariate and multivariate linear regression models predicting liver stiffness were conducted.

RESULTS

After excluding children with obesity, diabetes, or abnormal liver tests, 652 children were analysed. Among older children, mean liver stiffness was 4.45 kPa (95% confidence interval 4.34-4.56), and increased liver stiffness was associated with age, sedation status, and S probe use. In the younger group, the mean liver stiffness was 4.79 kPa (95% confidence interval 4.46-5.12), and increased liver stiffness was associated with sedation status and Caucasian race. In a subgroup analysis, hepatic steatosis on ultrasound was significantly associated with increased liver stiffness. We define a reference range for normal liver stiffness in healthy children as 2.45-5.56 kPa.

CONCLUSIONS

We have established TE-derived liver stiffness ranges for healthy children and propose an upper limit of liver stiffness in healthy children to be 5.56 kPa. We have identified increasing age, use of sedation, probe size, and presence of steatosis on ultrasound as factors that can significantly increase liver stiffness.

Health-related quality of life in pre-adolescent liver transplant recipients with biliary atresia: A cross-sectional study

OBJECTIVE

Pediatric recipients of liver transplantation (LT) often report lower Health-Related Quality of Life (HRQOL) than healthy controls when assessed on generic HRQOL measurement tools. The recent addition of the Pediatric Liver Transplant Quality of Life (PeLTQL), a novel disease-specific HRQOL instrument for pediatric LT recipients, into the clinical armamentarium of tools now routinely available to clinical care teams, provides the unique opportunity to identify disease-related challenges in children who have undergone this life-saving intervention. This study assesses HRQOL in pre-adolescent aged patients with a primary diagnosis of biliary atresia (BA) who underwent LT as an infant, using both generic and disease-specific HRQOL instruments validated for children. We also examined modifiable factors associated with HRQOL after pediatric LT.

METHODS

HRQOL was the primary outcome of this study assessed using the disease-specific PeLTQL and the generic Pediatric Quality of Life Inventory 4.0 (PedsQL). Exposure variables of interest included medication status (e.g., monotherapy, dual therapy) and participation in sports.

RESULTS

A total of 70 (56% female, mean age 9.89 ± 1.25 years) pediatric LT recipients (mean interval since LT was 9.0 ± 1.26 years) comprised the study cohort. LT recipients reported significantly lower PedsQL Scores relative to the general population. Immunosuppression monotherapy was associated with higher patient-reported PeLTQL Scores, and sports participation was associated with higher parent-reported PedsQL Scores.

CONCLUSIONS

Pre-adolescents who underwent LT as an infant with BA, self-report low HRQOL on both disease-specific and generic HRQOL tools. Further research targeting sports participation and simplifying immunosuppression may further optimize quality of life years restored by life-saving LT.

High Burden of Subclinical Cardiovascular Target Organ Damage After Pediatric Liver Transplantation

Cardiovascular (CV) events account for 8%-13% of deaths after liver transplantation (LT) in adulthood. Although CV risk factors (RFs) are present, little is known about the prevalence of subclinical CV target organ damage (TOD) in children after LT. The aim of this prospective observational study was to assess the prevalence of subclinical CV TOD in children after LT and to identify RFs contributing to CV damage as potential targets for clinical intervention. In this study, 104 children after LT (54% female, 46% male; aged 11.5 ± 3.8 years) underwent cross-sectional assessment of subclinical TOD by carotid-femoral pulse wave velocity (PWV), carotid intima-media thickness (IMT), and left ventricular mass index (LVMI). Results were correlated with the presence of CV RFs (obesity, hypertension, dyslipidemia, renal impairment, anemia, and microinflammation). Of the patients, 22% were exposed to 2 CV RFs, and 36% displayed 3 or more CV RFs. Pathological results for PWV, IMT, and LVMI were found in 21.9%, 57.0%, and 11.1% of patients, respectively. In the multivariate analysis, diastolic blood pressure (P = 0.01) and estimated glomerular filtration rate (eGFR; P = 0.03) were independently associated with PWV, eGFR (P = 0.005), and age at LT (P = 0.048) with IMT and body mass index with LVMI (P = 0.004). In conclusion, patients after pediatric LT carry a substantial burden of subclinical CV TOD. Identification of modifiable CV RFs opens opportunities for targeted intervention in order to reduce CV morbidity and mortality in the future.

Immune Status in Children Before Liver Transplantation-A Cross-Sectional Analysis Within the ChilsSFree Multicentre Cohort Study

Background: Both, markers of cellular immunity and serum cytokines have been proposed as potential biomarkers for graft rejection after liver transplantation. However, no good prognostic model is available for the prediction of acute cellular rejection. The impact of underlying disease and demographic factors on immune status before pediatric liver transplantation (pLTx) is still poorly understood. We investigated expression of immune markers before pLTx, in order to better understand the pre-transplant immune status. Improved knowledge of the impact of pre-transplant variables may enhance our understanding of immunological changes post pLTx in the future.

Methods: This is a cross-sectional analysis of data from the ChilSFree study, a European multicentre cohort study investigating the longitudinal patterns of immune response before and after pLTx. Immune cell counts and soluble immune markers were measured in 155 children 1–30 days before pLTx by TruCount analysis and BioPlex assays. Results were logarithmised due to skewed distributions and then compared according to age, sex, and diagnosis using t-tests, ANOVAs, and Tukey post-hoc tests. The association between immune markers at time of pLTx and patients' age was assessed using a fractional polynomial approach. Multivariable regression models were used to assess the relative contribution of each factor.

Results: Sex had no effect on immune status. We found strong evidence for age-specific differences in the immune status. The majority of immune markers decreased in a log-linear way with increasing age. T and B cells showed a sharp increase within the first months of life followed by a log-linear decline in older age groups. Several immune markers were strongly associated with underlying diagnoses. The effects of age and underlying disease remained virtually unchanged when adjusting for each other in multivariable models.

Discussion: We show for the first time that age and diagnosis are major independent determinants of cellular and soluble immune marker levels in children with end-stage liver disease. These results need to be considered for future research on predictive immune monitoring after pLTx.

Side effects and efficacy of renal sparing immunosuppression in pediatric liver transplantation-A single center matched cohort study

Immunosuppressive combination therapy with MMF can reduce CNI associated nephrotoxicity. We investigated effectiveness and safety of de novo MMF-tacrolimus based immunosuppression after pLTx. Patients after pLTx receiving immunosuppression with MMF/tacrolimus (MMF/TAC) were compared to retrospectively selected age- and diagnosis-matched patients with tacrolimus monotherapy (TAC) and cyclosporine/prednisolone therapy (CSA) (19 patients each, n = 57). Effectiveness, renal function and side effects were analyzed for 1 year after pLTx. Tacrolimus reduction in combination therapy (0.7 μg/L over the year) was lower than aspired (2 μg/L). Acute BPAR occurred equally in MMF/TAC and TAC groups (31.6% each), being slightly higher in CSA group (42.1%; OR = 1.5; 95% CI = 0.42-5.44; P = .5). GFR deteriorated comparably in all 3 groups (P < .01 each) without significant differences between the groups. Septicemia was detected significantly more often in MMF/TAC (73.6%) than in TAC (31.6%) (OR 4.17; 1.07-16.27; P = .04). EBV reactivation occurred more often in CSA patients (84.2%) than in MMF/TAC (47.4%; OR 5.16; 0.98-27.19; P = .05) and TAC patients (52.6%; OR 8.16; 1.48-44.89; P = .02) the same was true for other viral infections (47.4% (CSA) vs 15.8% (TAC); OR 4.21; 0.95-18.55; P = .05). Our study does not provide additional evidence for a benefit of initial use of MMF/TAC over TAC regarding renal function, but raises concerns regarding a potentially increased risk of serious infections under MMF/TAC compared to TAC monotherapy at equivalent renal outcome; our study is, however, limited by the minor CNI reduction in combination therapy.

Immune monitoring after pediatric liver transplantation - the prospective ChilSFree cohort study

Background

Although trough levels of immunosuppressive drugs are largely used to monitor immunosuppressive therapy after solid organ transplantation, there is still no established tool that allows for a validated assessment of functional degree of immunosuppression or the identification of clinically relevant over- or under-immunosuppression, depending on graft homeostasis. Reliable non-invasive markers to predict biopsy proven acute rejection (BPAR) do not exist. Literature data suggest that longitudinal measurements of immune markers might be predictive of BPAR, but data in children are scarce. We therefore propose an observational prospective cohort study focusing on immune monitoring in children after liver transplantation. We aim to describe immune function in a cohort of children before and during the first year after liver transplantation and plan to investigate how the immune function profile is associated with clinical and laboratory findings.

Methods

In an international multicenter prospective approach, children with end-stage liver disease who undergo liver transplantation are enrolled to the study and receive extensive immune monitoring before and at 1, 2, 3, 4 weeks and 3, 6, 12 months after transplantation, and whenever a clinically indicated liver biopsy is scheduled. Blood samples are analyzed for immune cell numbers and circulating levels of cytokines, chemokines and factors of angiogenesis reflecting immune cell activation. Statistical analysis will focus on the identification of trajectorial patterns of immune reactivity predictive for systemic non-inflammatory states, infectious complications or BPAR using joint modelling approaches.

Discussion

The ChilSFree study will help to understand the immune response after pLTx in different states of infection or rejection. It may provide insight into response mechanisms eventually facilitating immune tolerance towards the graft. Our analysis may yield an applicable immune panel for non-invasive early detection of acute cellular rejection, with the prospect of individually tailoring immunosuppressive therapy. The international collaborative set-up of this study allows for an appropriate sample size which is otherwise difficult to achieve in the field of pediatric liver transplantation.

Phenotypic spectrum and diagnostic pitfalls of ABCB4 deficiency depending on age of onset

Genetic variants in the adenosine triphosphate-binding cassette subfamily B member 4 (ABCB4) gene, which encodes hepatocanalicular phosphatidylcholine floppase, can lead to different phenotypes, such as progressive familial intrahepatic cholestasis (PFIC) type 3, low phospholipid-associated cholelithiasis, and intrahepatic cholestasis of pregnancy. The aim of this multicenter project was to collect information on onset and progression of this entity in different age groups and to assess the relevance of this disease for the differential diagnosis of chronic liver disease. Clinical and laboratory data of 38 patients (17 males, 21 females, from 29 families) with homozygous or (compound) heterozygous ABCB4 mutations were retrospectively collected. For further analysis, patients were grouped according to the age at clinical diagnosis of ABCB4-associated liver disease into younger age (<18 years) or adult age (≥18 years). All 26 patients diagnosed in childhood presented with pruritus (median age 1 year). Hepatomegaly and splenomegaly were present in 85% and 96% of these patients, respectively, followed by jaundice (62%) and portal hypertension (69%). Initial symptoms preceded diagnosis by 1 year, and 13 patients received a liver transplant (median age 6.9 years). Of note, 9 patients were misdiagnosed as biliary atresia, Alagille syndrome, or PFIC type 1. In the 12 patients with diagnosis in adulthood, the clinical phenotype was generally less severe, including intrahepatic cholestasis of pregnancy, low phospholipid-associated cholelithiasis, or (non)cirrhotic PFIC3. Conclusion: ABCB4 deficiency with onset in younger patients caused a more severe PFIC type 3 phenotype with the need for liver transplantation in half the children. Patients with milder phenotypes are often not diagnosed before adulthood. One third of the children with PFIC type 3 were initially misdiagnosed, indicating the need for better diagnostic tools and medical education. (Hepatology Communications 2018;2:504-514).

Diagnosis of monogenic liver diseases in childhood by next-generation sequencing

Next-generation sequencing (NGS) has opened up novel diagnostic opportunities for children with unidentified, but suspected inherited diseases. We describe our single-center experience with NGS diagnostics in standard clinical scenarios in pediatric hepatology. We investigated 135 children with suspected inherited hepatopathies, where initially no causative pathogenic variant had been identified, with an amplicon-based NGS panel of 21 genes associated with acute and chronic hepatopathies. In 23 of these patients, we detected pathogenic or likely pathogenic variants in 10 different genes. We present 6 novel variants. A total of 14 of these patients presented with the characteristic phenotype of the related hepatopathy. Nine patients showed only few or atypical clinical symptoms or presented with additional signs. In another 13 out of 135 cases, we detected variants of unknown significance (VUS) in 9 different genes. Only 2 of these patients showed characteristic phenotypes conclusive with the detected variants, whereas 11 patients showed unspecific or atypical phenotypes. Our multi-gene panel is a fast and comprehensive tool to diagnose inherited pediatric hepatopathies. We also illustrate the challenge of dealing with genetic variants and highlight arising clinical questions, especially in patients with atypical phenotypes.

Transition after pediatric liver transplantation - Perceptions of adults, adolescents and parents

AIM

To develop a locally adapted, patient-focused transition-program, we evaluated the perceptions of adult and adolescent patients and parents regarding transition-programs and transfer.

METHODS

We evaluated these perceptions by analyzing the responses of pre-transfer adolescents (n = 57), their parents (n = 57) and post-transfer adults (n = 138) from a cohort of pediatric-liver-transplant-patients using a self-designed questionnaire. Furthermore, we compared a responder group with a non-responder group as well as the provided answers with baseline characteristics and clinical outcomes to exclude selection bias, characterize high-risk patients for non-adherence and test for gender differences. Included in our study were all pre-transfer liver transplant and combined liver-kidney transplant recipients aged 11-19 currently under our care and their parents, as well as all post-transfer liver transplant and combined liver-kidney transplant recipients aged ≥ 17 years who had received a liver transplant and were treated at our center during childhood.

RESULTS

Fifty-seven (24 female) pre-transfer patients who received a transplant in the previous 8-186 mo (mean 93.9 mo, median 92 mo, SD 53.8 mo) and 138 (57 female) post-transfer patients who received a transplant in the preceding 2-29 years (mean 15.6 years, median 17, SD 6.90) met the inclusion criteria. A total of 67% of pre-transfer patients (71% of female; 64% of male; P = 0.78) and their parents replied. Additionally, 54% of post-transfer patients (26% of female; 48% of male; P = 0.01) replied. No differences in clinical outcomes were observed between the responder and non-responder groups, and responses did not differ significantly based on clinical complication rates, although they did differ based on gender and the location of medical follow-up after transfer. Adolescents were generally ambivalent toward transition programs. However, adults strongly supported transition programs.

CONCLUSION

Transition programs need to be developed in close collaboration with adolescents. The best clinical practices regarding transition should respect local circumstances, gender and the location of post-transfer medical follow-up.

Home monitoring and decision support for international liver transplant children

Complications may occur after a liver transplantation, therefore proper monitoring and care in the post-operation phase plays a very important role. Sometimes, monitoring and care for patients from abroad is difficult due to a variety of reasons, e.g., different care facilities. The objective of our research for this paper is to design, implement and evaluate a home monitoring and decision support infrastructure for international children who underwent liver transplant operation. A point-of-care device and the PedsQL questionnaire were used in patients' home environment for measuring the blood parameters and assessing quality of life. By using a tablet PC and a specially developed software, the measured results were able to be transmitted to the health care providers via internet. So far, the developed infrastructure has been evaluated with four international patients/families transferring 38 records of blood test. The evaluation showed that the home monitoring and decision support infrastructure is technically feasible and is able to give timely alarm in case of abnormal situation as well as may increase parent's feeling of safety for their children.

Personal decision-making processes for living related liver transplantation in children

Living related liver transplantation (LRLT) is a valuable transplant option for children with end-stage liver disease who face long waiting times on regular waiting lists. The subjection of a healthy adult to a potentially life-threatening operation can raise issues of freedom of choice, fear, and family conflict for the potential donors. We examined attitudes, fears, and influencing factors in the decision-making process for living liver donation for children in order to identify factors to improve support for living liver donors in the future. In a retrospective, questionnaire-based survey of 93 adults evaluated for living liver donation between 1997 and 2010, 47 of whom actually proceeded to donation, we asked about attitudes, motivation, fears, influencing factors, and well-being during the LRLT evaluation process and during the donation period. Answers were recorded on Likert scales and compared with Pearson's rho correlation and the Mann-Whitney U test as appropriate. Although there was a strong sense of a lack of alternatives among the donors, the majority of the donors felt free in their decision to donate. Donors who were asked to donate for a relative who was not their own child appeared at higher risk of lacking support and of feeling coerced. Family and social support and good and empathic information about the donation process were identified as key factors for donor well-being. In conclusion, potential living liver donors need to have adequate, sufficient, and empathic information, and they need to be provided a supportive framework, including family support, in order to promote their well-being. Care needs to be taken in identifying and counseling potential donors at risk of feeling coerced into donation.

Autophagy-enhancing drug carbamazepine diminishes hepatocellular death in fibrinogen storage disease

Fibrinogen storage disease (FSD) is a rare autosomal-dominant hereditary disorder characterized by hypofibrinogenemia and accumulation of fibrinogen aggregates within the hepatocellular endoplasmatic reticulum (ER). Some FSD patients present with elevated amino-transferases and fibrosis/cirrhosis similar to alpha-1-antitrypsin deficiency (ATD), also an ER storage disease. Pharmacological stimulation of autophagy has been shown to mediate clearance of protein aggregates and halt progression of liver fibrosis in in vivo models of ATD. Our aim was to evaluate the presence of autophagy and a possible response to autophagy-enhancing therapy in patients with FSD. Hepatic fibrosis was assessed by transient elastography in 2 newly identified FSD families with fibrinogen Aguadilla and Brescia mutations, encompassing 8 affected members. Available liver biopsies were assessed for autophagy. Two patients, who had had elevated alanine amino-transaminase levels (2-5 above upper limit of normal), were treated with the autophagy enhancer carbamazepine (CBZ). Transient elastography did not show evidence of significant fibrosis in any affected family members. Quantitative electron microscopy of one patient showed a 5.15-fold increase of late stage autophagocytic vacuoles compared to control livers. CBZ at low anticonvulsive treatment levels led to rapid normalization of alanine-aminotransferase and decrease of caspase-cleaved and uncleaved cytokeratin-18 fragments (M30 and M65). These effects reversed after discontinuation of treatment. Response to CBZ may be mediated by pharmacologically enhanced autophagy resulting in reduction of aggregate-related toxicity in FSD. These results suggest clinical applicability of pharmacological stimulation of autophagy in FSD, but potentially also in other related disorders.

The use of transient elastography and non-invasive serum markers of fibrosis in pediatric liver transplant recipients

The use of non-invasive markers to diagnose liver allograft fibrosis is not well established in children after LTx. TE, FT, and ELF score were performed in 117 liver-transplanted children (60M, 8.9 [0.5-18.5] yr) and 336 healthy controls. Liver biopsy was available in 36 children. Results of histology and non-invasive markers were compared using correlation coefficient or Mann-Whitney U-test as appropriate. TE correlated best with histological degree of fibrosis (r = 0.85 vs. r = 0.04 [FT] or r = -0.38 [ELF]). Liver stiffness values for transplanted children without fibrosis were significantly higher than those of healthy controls (7.55 [5.4-20.4] kPa vs. 4.5 [2.5-8.9] kPa). Presence of rejection was a potent confounder for the performance of TE. Both TE and FT reflected clinical changes (acute rejection, cholestasis, increasing fibrosis) in a total of 16 patients who underwent serial measurements. TE correlates better with histological degree of fibrosis in liver-transplanted children than FT or ELF, but an individual baseline value needs to be determined for each patient. Normal or cutoff values for pathological degrees of fibrosis cannot be transferred from non-transplanted children. Follow-up studies, preferably with protocol biopsies, might help to improve the diagnostic quality of TE.

Results of single-center screening for chronic hepatitis E in children after liver transplantation and report on successful treatment with ribavirin

RNA screening for HEV in 22 liver-transplanted children with chronic graft hepatitis out of a cohort of 267 liver-transplanted children detected a single patient with chronic HEV infection. Although this patient remained viremic for 33 months, anti-HEV-IgG was not detectable with MP assay but with Wantai assay. We present the first case of successful ribavirin therapy in an immunosuppressed child with chronic HEV infection. In conclusion, chronic HEV infection in immunosuppressed children may not be detectable employing serological assays. Therefore, the most reliably screening method is screening for HEV-RNA. Chronic HEV infection in children can successfully be treated with ribavirin.

Hepatic fibrosis in paediatric liver disease

Liver fibrosis is the common endpoint of chronic liver disease of variable aetiology. Liver injury induces excess deposition of extracellular matrix via inflammatory pathways, which in turn results in distortion of the vascular liver architecture. The two features combine to cause portal hypertension and reduced hepatocellular function. Diagnosis of liver fibrosis is made by liver biopsy, but non invasive tests like serological markers or elastographic methods are increasingly being recognized as useful tools in the diagnosis of fibrosis. Treatment options that exceed the treatment of the underlying liver disease are still largely experimental.

Acceptance and adverse events of the 2009 H1N1 vaccination in immunosuppressed pediatric liver transplant recipients

A retrospective analysis of H1N1 vaccination in 127 children at ≥ 1 year after liver transplantation found only moderate acceptance (56%) of the vaccination. Physical adverse events were of moderate severity, but frequent (74%). Protection against infection was good, with infection rates of 4% in vaccinated children versus 25% in nonvaccinated children.

Kidney and colon electrolyte transport in CHIF knockout mice

Corticosteroid hormone induced factor (CHIF) is a small epithelial-specific protein regulated by aldosterone and K+ intake. It is a member of the FXYD family of single span transmembrane proteins involved in the regulation of ion transport. Recent data have suggested that CHIF interacts with the a subunit of the Na+-K+-ATPase and increases the pump's affinity to cell Na+. CHIF knockout (KO) mice have mild renal phenotype under low Na+ or high K+ diets. The present study further characterizes kidney electrolyte metabolism in CHIF KO mice and describes abnormalities in the colonic ion transport function. Kidney: KO mice were not compromised in salt and water balance under resting conditions. Fractional excretions (FE) of Na+ and K+ were normal and the animals had no deficit in the adaptation to low Na+ or high K+ intake. Glucocorticoid treatment did not unmask any difference. The effects of amiloride on Na+ absorption were not different at any treatment protocol. In contrast, FEK+ was reduced by 35% in KO mice under low Na+ intake. COLON: Amiloride inhibitable Na+ absorption was reduced in distal colon by 42%, 54% and 58% under control conditions, glucocorticoid treatment and low Na+ intake, respectively. Also, the cAMP dependent ion transport was significantly diminished. Forskolin induced equivalent short circuit current (I'SC) was reduced by 41%, 32% and 58%, under control conditions, high K+, and low Na+ intake, respectively. The present findings support a role of CHIF as an indirect modulator of several different ion transport mechanisms and are consistent with regulation of the Na+-K+-ATPase as the common denominator.

Induction of the epithelial Na+ channel via glucocorticoids in mineralocorticoid receptor knockout mice

Epithelial Na+ channel (ENaC) activity in kidney and colon is stimulated by aldosterone acting on the mineralocorticoid receptor (MR). MR and the glucocorticoid receptor (GR) show high homology in their DNA-binding domain and have similar affinities to mineralo- and glucocorticoids. We therefore asked whether the glucocorticoid-mediated activation of ENaC is restricted to the presence of MR and used the MR knockout mouse model to address this question. Due to their MR deficiency and the consecutive reduction of ENaC activity these mice die as neonates, and even after appropriate substitution therapy adult MR knockout mice suffer from high Na+ loss and hyperkalemia. In the present study, glucocorticoid treatment restored plasma K+ and almost normalized the fractional excretions of Na+ (FENa+) and K+ (FEK+) in adult salt-substituted MR knockout mice, while the effect of amiloride on FENa+ and FEK+ was augmented in these animals. In order to estimate ENaC activity, measurements of transepithelial equivalent short-circuit current (Isc) were performed. Glucocorticoids induced an amiloride-sensitive Na+ absorption in renal cortical collecting duct and distal colon of MR-/- of about 25% and 50% of the currents observed in glucocorticoid-treated wild-type mice, respectively. In the colon glucocorticoid treatment increased the mRNA abundance of all three ENaC subunits, in the kidney only alpha-ENaC was increased. The regulation of ENaC expression was the same in both genotypes and thus irrespective of the presence of MR. These data show that MR is no prerequisite for the activation of ENaC transcription and activity, and that the respective mechanisms can be stimulated via GR.