Genetic landscape of pediatric acute liver failure of indeterminate origin.

BACKGROUND AND AIMS: Pediatric acute liver failure (PALF) is a life-threatening condition. In Europe, the main causes are viral infections (12%-16%) and inherited metabolic diseases (14%-28%). Yet, in up to 50% of cases the underlying etiology remains elusive, challenging clinical management, including liver transplantation. We systematically studied indeterminate PALF cases referred for genetic evaluation by whole-exome sequencing (WES), and analyzed phenotypic and biochemical markers, and the diagnostic yield of WES in this condition. APPROACH AND RESULTS: With this international, multicenter observational study, patients (0-18 y) with indeterminate PALF were analyzed by WES. Data on the clinical and biochemical phenotype were retrieved and systematically analyzed. RESULTS: In total, 260 indeterminate PALF patients from 19 countries were recruited between 2011 and 2022, of whom 59 had recurrent PALF. WES established a genetic diagnosis in 37% of cases (97/260). Diagnostic yield was highest in children with PALF in the first year of life (41%), and in children with recurrent acute liver failure (64%). Thirty-six distinct disease genes were identified. Defects in NBAS (n=20), MPV17 (n=8), and DGUOK (n=7) were the most frequent findings. When categorizing, the most frequent were mitochondrial diseases (45%), disorders of vesicular trafficking (28%), and cytosolic aminoacyl-tRNA synthetase deficiencies (10%). One-third of patients had a fatal outcome. Fifty-six patients received liver transplantation. CONCLUSIONS: This study elucidates a large contribution of genetic causes in PALF of indeterminate origin with an increasing spectrum of disease entities. The high proportion of diagnosed cases and potential treatment implications argue for exome or in future rapid genome sequencing in PALF diagnostics.

Cell-based BSEP trans-inhibition: A novel, non-invasive test for diagnosis of antibody-induced BSEP deficiency.

Background & Aims: Antibody-induced bile salt export pump deficiency (AIBD) is an acquired form of intrahepatic cholestasis, which may develop following orthotopic liver transplantation (OLT) for progressive familial intrahepatic cholestasis type 2 (PFIC-2). Approximately 8-33% of patients with PFIC-2 who underwent a transplant develop bile salt export pump (BSEP) antibodies, which trans-inhibit this bile salt transporter from the extracellular, biliary side. AIBD is diagnosed by demonstration of BSEP-reactive and BSEP-inhibitory antibodies in patient serum. We developed a cell-based test directly measuring BSEP trans-inhibition by antibodies in serum samples to confirm AIBD diagnosis. Methods: Sera from healthy controls and cholestatic non-AIBD or AIBD cases were tested (1) for anticanalicular reactivity by immunofluorescence staining of human liver cryosections, (2) for anti-BSEP reactivity by immunofluorescence staining of human embryonic kidney 293 (HEK293) cells expressing BSEP-enhanced yellow fluorescent protein (EYFP) and immunodetection of BSEP-EYFP on Western blot, and (3) for BSEP trans-inhibition using HEK293 cells stably expressing Na+/taurocholate cotransporting polypeptide (NTCP)-mCherry and BSEP-EYFP. The trans-inhibition test uses [3H]-taurocholate as substrate and is divided into an uptake phase dominated by NTCP followed by BSEP-mediated export. For functional analysis, sera were bile salt depleted. Results: We found BSEP trans-inhibition by seven sera containing anti-BSEP antibodies, but not by five cholestatic or nine control sera, all lacking BSEP reactivity. Prospective screening of a patient with PFIC-2 post OLT showed seroconversion to AIBD, and the novel test method allowed monitoring of treatment response. Notably, we identified a patient with PFIC-2 post OLT with anti-BSEP antibodies yet without BSEP trans-inhibition activity, in line with asymptomatic presentation at serum sampling. Conclusions: Our cell-based assay is the first direct functional test for AIBD and allows confirmation of diagnosis as well as monitoring under therapy. We propose an updated workflow for AIBD diagnosis including this functional assay. Impact and Implications: Antibody-induced BSEP deficiency (AIBD) is a potentially serious complication that may affect patients with PFIC-2 after liver transplantation. To improve its early diagnosis and thus immediate treatment, we developed a novel functional assay to confirm AIBD diagnosis using a patient's serum and propose an updated diagnostic algorithm for AIBD.

Progressive familial intrahepatic cholestasis-outcome and time to transplant after biliary diversion according to genetic subtypes.

Background: Progressive familial intrahepatic cholestasis (PFIC) is a heterogeneous disease characterized by progressive cholestasis in early childhood. Surgical therapy aims at preventing bile absorption either by external or internal biliary diversion (BD). Several different genetic subtypes encode for defects in bile transport proteins, and new subtypes are being discovered ongoingly. Overall, the literature is scarce, however, accumulating evidence points to PFIC 2 having a more aggressive course and to respond less favorable to BD. With this knowledge, we aimed to retrospectively analyze the long-term outcome of PFIC 2 compared to PFIC 1 following BD in children at our center. Methods: Clinical data and laboratory findings of all children with PFIC, who were treated and managed in our hospital between 1993 and 2022, were analyzed retrospectively. Results: Overall, we treated 40 children with PFIC 1 (n = 10), PFIC 2 (n = 20) and PFIC 3 (n = 10). Biliary diversion was performed in 13 children (PFIC 1, n = 6 and 2, n = 7). Following BD, bile acids (BA) (p = 0.0002), cholesterol (p < 0.0001) and triglyceride (p < 0.0001) levels significantly decreased only in children with PFIC 1 but not in PFIC 2. Three out of 6 children (50%) with PFIC 1 and 4 out of 7 children (57%) with PFIC 2 required liver transplantation despite undergoing BD. On an individual case basis, BA reduction following BD predicted this outcome. Of the 10 children who had PFIC 3, none had biliary diversion and 7 (70%) required liver transplantation. Conclusion: In our cohort, biliary diversion was effective in decreasing bile acids, cholesterol levels as well as triglycerides in the serum only in children with PFIC 1 but not PFIC 2. On an individual case level, a decrease in BA following BD predicted the need for liver transplantation.

Parents' Perceptions of the Effectiveness of Music Therapy on Their Chronically Ill Children.

Chronic disease in a child, with the associated hospital stays, places considerable demands on the child and their family. The aim of this study was to investigate the parents' perceptions of the music therapy used with their child during a hospital stay and to determine whether they felt that it reduced the child's anxiety and stress generated by hospital admission. We hypothesized that the use of live music therapy from a music therapist would positively support these patients in everyday clinical practice, promote their wellbeing, and have positive impacts on their vital signs and blood pressure. Children with chronic gastroenterological and nephrological diseases included in this prospective study received live music therapy with a median duration of 41 min (range from 12 to 70 min) two to four times per week until discharged from the hospital. At the time of discharge, the parents were asked to complete a Likert-style questionnaire to evaluate the music therapy. Seven items were related to general questions about the patients and sessions, and eleven items evaluated the personal perceptions of the parents. Music therapy was conducted in 83 children, with a median age of 3 years (range from 1 month to 18 years). All parents (100%) completed the questionnaire at the time of discharge. Seventy-nine percent of the parents stated that their children were able to enjoy the music therapy sessions without being stressed. In addition, 98% of the respondents said that they were grateful for the music therapy their children received (97% fully agreed and 1% rather agreed). All parents considered music therapy to be beneficial for their child. The parents' responses reflected the view that music therapy is beneficial to patients. According to the parents, music therapy can be integrated effectively in the inpatient clinical setting and can support children with chronic illnesses during their hospital stay.

Effects of Music Therapy on Vital Signs in Children with Chronic Disease.

BACKGROUND: Recent research found evidence supporting music therapy for hospitalized children with chronic diseases. The aim of this study was to investigate the effect of music therapy on hospitalized children's vital signs. METHODS: In this prospective study, children with chronic gastroenterological and nephrological diseases received active or receptive music therapy two to four times a week until discharge from hospital at the pediatric special care unit (SCU) and pediatric intensive care unit (ICU). Baseline and post-therapy heart rate, oxygen saturation and blood pressure were recorded and analyzed as control values at three points on the same day when the children were alone in their patient room at rest. RESULTS: A total of 83 children, median 3 age of years (range one month to eighteen years) received music therapy. In total, 377 music therapy sessions were treated: 200 receptive therapy (78 ICU, 122 SCU) and 177 with active therapy (0 ICU, 177 SCU). Music therapy interventions showed changes in vital signs during music therapy sessions. After music therapy, heart rates decreased by 18 beats per minute (95% confidence interval (CI), -19.4 to (-16.8)), oxygen saturation increased by 2.3% (95% CI, 2.2 to 2.5), systolic blood pressure decreased by 9.2 (95% CI, -10.6 to -7.7) and diastolic blood pressure decreased by 7.9 (95% CI, -9.6 to -6.3). When music therapy was applied at the SCU (ICU), heart rates significantly reduced by 17.9 (18.9) beats per min, oxygen saturation increased by 2.4% (2.1%) and blood pressure reduced by 9.2 (2.8) mmHg (systolic) and 7.9 (0.3) mmHg (diastolic). Almost all control values were better than directly before the intervention. However, after music therapy intervention, the children showed better values in vital signs compared to being alone in their patient room. CONCLUSION: Music therapy is an added value for children with kidney and liver/gastrointestinal diseases during their hospital stay.

A Retrospective Analysis of Rituximab Treatment for B Cell Depletion in Different Pediatric Indications.

Background: Rituximab (RTX) is used in cancer therapy as well as in the treatment of autoimmune diseases and alloimmune responses after transplantation. It depletes the disease-causing B cells by binding to the CD (cluster of differentiation) 20 antigen. We evaluate different pediatric treatment protocols (via fixed treatment schedule, B cell- or symptom-controlled) and their therapeutic effects. Methods: Demographic information, clinical and laboratory characteristics, and special laboratory values such as immunoglobulin G (IgG), CD19 positive B cells and Epstein-Barr viral load were retrospectively analyzed in children treated with RTX between 2008 and 2016. Results: Seventy-six patients aged 1 to 19 (median 13) years were treated with 259 RTX infusions. The spectrum of diseases was very heterogeneous. RTX led to a complete depletion of the B cells. The reconstitution time varied between patients and was dependent on the application schedule (median 11.8 months). Fourteen out of 27 (52%) patients developed hypogammaglobulinaemia. The risk of IgG deficiency was 2.6 times higher in children under 4 years of age than in olderones. In the last group IgG deficiency developed in only 38% of the cases (n = 8). Recurrent and severe infections were observed each in 11/72 (15%) patients. Treatment-related reactions occurred in 24/76 (32%) cases; however, treatment had to be discontinued in only 1 case. In 16/25 (76%), the Epstein-Barr viral load dropped below the detection limit after the first RTX infusion. Conclusion: RTX is an effective and well-tolerated drug for the treatment of oncological diseases as well as autoimmune and alloimmune conditions in children. B cell depletion and reconstitution varies both intra- und interindividually, suggesting that symptom-oriented and B cell-controlled therapy may be favorable. Treatment-related reactions, IgG deficiency and infections must be taken into account.

Role of Tacrolimus C/D Ratio in the First Year After Pediatric Liver Transplantation.

Background: The calcineurin inhibitor (CNI) tacrolimus (TAC) is a cornerstone agent in immunosuppressive therapy in pediatric liver transplantation (LTX). Adverse effects limit the use of CNI. In adults, calculating the individual TAC metabolism rate allows to estimate the transplant recipient's risk for therapy-associated complications. Methods: A retrospective, descriptive data analysis was performed in children who had undergone LTX in 2009-2017 and had received TAC twice daily in the first year after LTX. A weight-adjusted concentration/dose ratio (C/D ratio) was calculated [TAC trough level/(daily TAC dose/body weight)] every 3 months after LTX to estimate the average individual TAC metabolism rate. Depending on the C/D ratio, all patients were divided into two groups: fast metabolizers (FM) and slow metabolizers (SM). Clinical and laboratory parameters were analyzed as risk factors in both groups. Results: A total of 78 children (w 34, m 44, median age at LTX 2.4; 0.4-17.0 years) were enrolled in the study. FM (SM) had a mean C/D ratio of <51.83 (≥51.83) ng/ml/(mg/kg). FM were younger at the time of LTX (median age 1.7; 0.4-15.8 years) than SM (5.1, 0.4-17.0), p = 0.008. FM were more likely to have biliary atresia (20/39, 51%) compared to SM (11/39, 28%), p = 0.038, whereas SM were more likely to have progressive familial intrahepatic cholestasis (9/39, 23%) vs. in FM (1/39, 3%), p = 0.014. Epstein-Barr virus (EBV) infection occurred more frequently in FM (27/39, 69%) than SM (13/39, 33%), p = 0.002. Three FM developed post-transplant lymphoproliferative disorder. The annual change of renal function did not differ in both groups (slope FM 1.2 ± 0.6; SM 1.4 ± 0.8 ml/min/1.73 m2 per year, and p = 0.841). Conclusions: Calculation of individual, weight-adjusted TAC C/D ratio is a simple, effective, and cost-efficient tool for physicians to estimate the risk of therapy-associated complications and to initiate individual preventive adjustments after pediatric LTX. Lower TAC levels are tolerable in FM, especially in the presence of EBV infection, reduced renal function, or when receiving a liver transplant in the first 2 years of life.

Congenital Diarrhea and Cholestatic Liver Disease: Phenotypic Spectrum Associated with MYO5B Mutations.

Myosin Vb (MYO5B) is a motor protein that facilitates protein trafficking and recycling in polarized cells by RAB11- and RAB8-dependent mechanisms. Biallelic MYO5B mutations are identified in the majority of patients with microvillus inclusion disease (MVID). MVID is an intractable diarrhea of infantile onset with characteristic histopathologic findings that requires life-long parenteral nutrition or intestinal transplantation. A large number of such patients eventually develop cholestatic liver disease. Bi-allelic MYO5B mutations are also identified in a subset of patients with predominant early-onset cholestatic liver disease. We present here the compilation of 114 patients with disease-causing MYO5B genotypes, including 44 novel patients as well as 35 novel MYO5B mutations, and an analysis of MYO5B mutations with regard to functional consequences. Our data support the concept that (1) a complete lack of MYO5B protein or early MYO5B truncation causes predominant intestinal disease (MYO5B-MVID), (2) the expression of full-length mutant MYO5B proteins with residual function causes predominant cholestatic liver disease (MYO5B-PFIC), and (3) the expression of mutant MYO5B proteins without residual function causes both intestinal and hepatic disease (MYO5B-MIXED). Genotype-phenotype data are deposited in the existing open MYO5B database in order to improve disease diagnosis, prognosis, and genetic counseling.

Protocol liver biopsies in stable long-term pediatric liver transplant recipients: risk or benefit?

BACKGROUND: Follow-up after pediatric liver transplantation (LTX) is challenging and needs to be refined to extend graft survival as well as general functional health and patients´ quality of life. Strategies towards individual immunosuppressive therapy seem to play a key role. Our aim was to evaluate protocol liver biopsies (PLB) as a tool in personalized follow up after pediatric LTX. PATIENTS AND METHODS: Our retrospective analysis evaluates 92 PLB in clinically asymptomatic pediatric patients after LTX between 2009 and 2019. Histological findings were characterized using the Desmet scoring system. In addition to PLB, other follow-up tools like laboratory parameters, ultrasound imaging and transient elastography were evaluated. Risk factors for development of fibrosis or inflammation were analyzed. RESULTS: PLB revealed a high prevalence of graft fibrosis (67.4%) and graft inflammation (47.8%). Graft inflammation was significantly (P = 0.0353*) more frequent within the first 5 years after transplantation compared to later time points. Besides conventional ultrasound, the measurement of liver stiffness using transient elastography correlate with stage of fibrosis (r = 0.567, P = <0.0001***). Presence of donor-specific anti-human leukocyte antigen antibodies in blood correlates with grade of inflammation in PLB (r = 0.6040, P = 0.0018 **). None of the patients who underwent PLB suffered from intervention-related complications. Histopathological results had an impact on clinical decision making in one-third of all patients after PLB. CONCLUSION: PLB are a safe and useful tool to detect silent immune-mediated allograft injuries in the context of normal liver parameters.

Case Report: Hepatic Adenoma in a Child With a Congenital Extrahepatic Portosystemic Shunt.

Congenital extrahepatic portosystemic shunts (CEPS), previously also described as Abernethy malformations, are rare malformations in which the extrahepatic portal system directly communicates with the vena cava inferior, thereby bypassing the liver. A hypoplastic portal vein (PV) exists in most cases. CEPS have been associated with the development of liver nodules, ranging from mostly focal nodular hyperplasia (FNH) to hepatic adenoma (HA) and even hepatocellular carcinoma (HCC). Tumor development in CEPS may be due to changes in perfusion pressures, oxygen supply or endocrine imbalances. It is important to rule out CEPS in children with liver tumors, because resection could impede future shunt occlusion procedures, and benign masses may regress after shunt occlusion. Here, we review the case of a 9-years-old male with CEPS and hepatic nuclear Factor 1-alpha (HNF-1-alpha) inactivated HA to raise awareness of this condition and review histopathological changes in the liver of CEPS.

Genotypic diversity and phenotypic spectrum of infantile liver failure syndrome type 1 due to variants in LARS1.

PURPOSE: Biallelic variants in LARS1, coding for the cytosolic leucyl-tRNA synthetase, cause infantile liver failure syndrome 1 (ILFS1). Since its description in 2012, there has been no systematic analysis of the clinical spectrum and genetic findings. METHODS: Individuals with biallelic variants in LARS1 were included through an international, multicenter collaboration including novel and previously published patients. Clinical variables were analyzed and functional studies were performed in patient-derived fibroblasts. RESULTS: Twenty-five individuals from 15 families were ascertained including 12 novel patients with eight previously unreported variants. The most prominent clinical findings are recurrent elevation of liver transaminases up to liver failure and encephalopathic episodes, both triggered by febrile illness. Magnetic resonance image (MRI) changes during an encephalopathic episode can be consistent with metabolic stroke. Furthermore, growth retardation, microcytic anemia, neurodevelopmental delay, muscular hypotonia, and infection-related seizures are prevalent. Aminoacylation activity is significantly decreased in all patient cells studied upon temperature elevation in vitro. CONCLUSION: ILFS1 is characterized by recurrent elevation of liver transaminases up to liver failure in conjunction with abnormalities of growth, blood, nervous system, and musculature. Encephalopathic episodes with seizures can occur independently from liver crises and may present with metabolic stroke.

[Histopathological diagnosis and differential diagnosis of nonalcoholic fatty liver disease]. / Histopathologische Diagnostik und Differenzialdiagnostik der nichtalkoholischen Fettlebererkrankung.

Fatty liver disease is a rising problem worldwide, particularly due to metabolic syndrome. The current prevalence is 20-30%, but a further increase is expected whereby children will also be increasingly affected. The presence of fat in hepatocytes is known as steatosis or, in the case of nonalcoholic origin, nonalcoholic fatty liver (NAFL). It is basically reversible, but can progress to steatohepatitis (NASH) as an active and progressive form of fatty liver disease due to continuous cell damage. This leads to progressive liver fibrosis up to end-stage liver cirrhosis. The gold standard of diagnosis is liver biopsy, in which obesity, inflammation, and hepatocellular damage (hepatocellular ballooning) are assessed for the distinction between NAFL and NASH. The extent of fibrosis indicates the progress of the disease. Childhood and adult fatty liver diseases differ morphologically, particularly in the location and amount of fat, inflammation, and fibrosis. Alcoholic and nonalcoholic fatty liver disease/steatohepatitis cannot be reliably differentiated by histology. Clinical parameters must also be taken into consideration for the differential diagnosis of other diseases associated with fatty liver. The main therapeutic goal is to reduce insulin resistance, which can be achieved through weight loss and lifestyle changes. Recently, however, drug therapies have also become available as a promising therapeutic option.

Mutation in ITCH Gene Can Cause Syndromic Multisystem Autoimmune Disease With Acute Liver Failure.

Pediatric intractable autoimmune hepatitis is rare and may be responsible for acute liver failure. Mutations in the itchy E3 ubiquitin protein ligase (ITCH) gene (located on chromosome 20q11.22) can lead to a deficiency of the encoded protein, resulting in increased T-cell activity with lack of immune tolerance and manifestation of a complex systemic autoimmune disease. A 1-year-old girl of consanguineous parents received a liver transplant (LT) because of acute liver failure attributed to a drug-induced hypereosinophilic syndrome with positive liver-kidney-mikrosome-2 antibodies. Notable findings were syndromic features, dystrophy, short stature, psychomotor retardation, and muscular hypotonia. Later, we saw corticosteroid-sensitive rejections as well as a systemic autoimmune disease with detection of specific antibodies (de novo autoimmune hepatitis, thyroiditis with exophthalmos, diabetes mellitus type 1, and immune neutropenia). Histologically, liver cirrhosis with lobular inflammatory infiltrates, giant-cell hepatitis, and ductopenia was verified in chronic cholestasis. Shortly after a second LT, a comparable liver histology could be detected, and viral, bacterial, and mycotic infections deteriorated the general health condition. Because of refractory pancytopenia related to portal hypertension and hypersplenism, a posttransplant lymphoproliferative disorder was excluded. One year after the second LT, epidural and subdural bleeding occurred. Three months afterward, the girl died of sepsis. Postmortem, whole-exome sequencing revealed a homozygous mutation in the ITCH gene. A biallelic mutation in ITCH can cause a severe syndromic multisystem autoimmune disease with the above phenotypic characteristics and acute liver failure because of autoimmune hepatitis. This case reveals the importance of ubiquitin pathways for regulation of the immune system.

Imaging of the intrahepatic portal vein in children with extrahepatic portal vein thrombosis - Comparison of magnetic resonance imaging and retrograde portography.

PURPOSE: Extrahepatic portal vein thrombosis (EPVT) is one major cause of portal hypertension in children. Surgical reinstallation of portal venous flow can be achieved in patients with patent intrahepatic portal venous system/Rex recess. Our study aimed to compare the ability of magnetic resonance imaging (MRI) and retrograde portography (RP) to assess patency of the intrahepatic portal venous system in children with EPVT. METHODS: All pediatric patients with EPVT who were examined with contrast enhanced MRI (1.5 T) and invasive RP between 2013 and 2017 were included in this retrospective study. Medical records were reviewed for demographic, biochemical and clinical data. Patency of the Rex recess as detected by MRI and RP was retrospectively reviewed. RESULTS: Sixteen children (7.6 ±â€¯5.0 years) with EPVT were included. Sensitivity, specificity, positive and negative predictive value for the detection of patent Rex recess by MRI compared to RP were 55%, 57%, 63% and 50%. Diagnostic accuracy was 56%. Diagnostic failure of MRI compared to RP was explained by the following: I. Problems differentiating collaterals from portal venous vessels II. Incapability showing dynamic blood flow in compromised portal venous flow III. Poor spatial resolution, especially in small children. CONCLUSION: RP is a reliable method for the visualization of the Rex recess and the intrahepatic portal venous system in children with EPVT, whereas MRI has shown to be unsuitable for the assessment of the intrahepatic portal vein in these patients. In the preoperative setup, we recommend both procedures, RP and MRI for the visualization of the intrahepatic portal venous system, and the extrahepatic vessels, respectively. LEVEL OF EVIDENCE: Level III.

Undue Elevation of Procalcitonin in Pediatric Paracetamol Intoxication is Not Explained by Liver Cell Injury Alone.

INTRODUCTION AND AIM: Procalcitonin is widely used as a biomarker to distinguish bacterial infections from other etiologies of systemic inflammation. Little is known about its value in acute liver injury resulting from intoxication with paracetamol. MATERIAL AND METHODS: We performed a single-center retrospective analysis of the procalcitonin level, liver synthesis, liver cell damage and renal function of patients admitted with paracetamol-induced liver injury to a tertiary care children's hospital. Children with acute liver failure due to other reasons without a bacterial or fungal infection served as the control group. Twelve patients with acute paracetamol intoxication and acute liver injury were compared with 29 patients with acute liver failure. RESULTS: The procalcitonin levels were higher in children with paracetamol intoxication than in patients with acute liver failure without paracetamol intoxication (median 24.8 (0.01-55.57) ng/mL vs. 1.36 (0.1-44.18) ng/mL; p < 0.005), although their liver and kidney functions were better and the liver cell injury was similar in both groups. Outcome analysis showed a trend towards better survival without transplantation in patients with paracetamol intoxication (10/12 vs. 15/29). Within each group, procalcitonin was significantly correlated with alanine aminotransferase and aspartate aminotransferase but was not correlated with the International Normalized Ratio or paracetamol blood levels in the paracetamol group. In conclusion, paracetamol intoxication leads to a marked increase in procalcitonin serum levels, which are significantly higher than those seen in acute liver failure. CONCLUSION: The underlying mechanism is neither caused by infection nor fully explained by liver cell death alone and remains to be determined.

Sequencing of FIC1, BSEP and MDR3 in a large cohort of patients with cholestasis revealed a high number of different genetic variants.

BACKGROUND & AIMS: The bile salt export pump (BSEP, ABCB11), multidrug resistance protein 3 (MDR3, ABCB4) and the ATPase familial intrahepatic cholestasis 1 (FIC1, ATP8B1) mediate bile formation. This study aimed to determine the contribution of mutations and common variants in the FIC1, BSEP and MDR3 genes to cholestatic disorders of differing disease onset and severity. METHODS: Coding exons with flanking intron regions of ATP8B1, ABCB11, and ABCB4 were sequenced in cholestatic patients with assumed genetic cause. The effects of new variants were evaluated by bioinformatic tools and 3D protein modeling. RESULTS: In 427 patients with suspected inherited cholestasis, 149 patients carried at least one disease-causing mutation in FIC1, BSEP or MDR3, respectively. Overall, 154 different mutations were identified, of which 25 were novel. All 13 novel missense mutations were disease-causing according to bioinformatics analyses and homology modeling. Eighty-two percent of patients with at least one disease-causing mutation in either of the three genes were children. One or more common polymorphism(s) were found in FIC1 in 35.3%, BSEP in 64.3% and MDR3 in 72.6% of patients without disease-causing mutations in the respective gene. Minor allele frequencies of common polymorphisms in BSEP and MDR3 varied in our cohort compared to the general population, as described by gnomAD. However, differences in ethnic background may contribute to this effect. CONCLUSIONS: In a large cohort of patients, 154 different variants were detected in FIC1, BSEP, and MDR3, 25 of which were novel. In our cohort, frequencies for risk alleles of BSEP (p.V444A) and MDR3 (p.I237I) polymorphisms were significantly overrepresented in patients without disease-causing mutation in the respective gene, indicating that these common variants can contribute to a cholestatic phenotype. LAY SUMMARY: FIC1, BSEP, and MDR3 represent hepatobiliary transport proteins essential for bile formation. Genetic variants in these transporters underlie a broad spectrum of cholestatic liver diseases. To confirm a genetic contribution to the patients' phenotypes, gene sequencing of these three major cholestasis-related genes was performed in 427 patients and revealed 154 different variants of which 25 have not been previously reported in a database. In patients without a disease-causing mutation, common genetic variants were detected in a high number of cases, indicating that these common variants may contribute to cholestasis development.

Etiology, outcome and prognostic factors of childhood acute liver failure in a German Single Center.

Pediatric acute liver failure (PALF) is a progressive, potentially fatal clinical syndrome occurring in previously healthy children. Our study aimed to determine the current leading causes of PALF in a single center in Germany, identifying possible prognostic markers. Thirty-seven pediatric patients with PALF were included. Medical records were reviewed for demographic, laboratory and clinical data. Laboratory results on admission and at peak value, PELD and MELD score on admission, and intensive care support were assessed. Fifteen patients recovered spontaneously, 14 died without transplantation, and 8 received a liver transplant. Patients who survived were significantly older than patients who died. Specific causes of PALF could be identified as infectious diseases (16%), metabolic diseases (14%), toxic liver injury (11%), immunologic diseases (8%), or vascular diseases (8%). Causes of PALF remained indeterminate in 43%. High ammonia, low albumin, and low ALT levels on admission were associated with worse outcome. Absence of need of ventilation, hemodialysis, and circulatory support predicted spontaneous recovery. In conclusion, infections are the most common known cause of PALF. However, in a large proportion of patients the cause for PALF remains cryptic. Ammonia and albumin levels may be of prognostic value to predict outcomes.

First case studies of successful ABO-incompatible living-related liver transplantation in infants in Germany.

AIM: A series study mainly from Asia suggests that ABO-incompatible (ABOi) living-related liver transplantation (LRLT) for pediatric recipients is associated with excellent short- and long-term graft and patient survival. Until now, ABOi LRLT has been rarely performed in Europe. The aim of this study was to analyze the safety and early results of an ABOi LRLT in a German high-volume pediatric liver transplant center. METHODS: Six consecutive pediatric patients (four males and two females) were included in this prospective study from January, 2010 to January, 2013 with a median age of 13 months (range, 6-30 months) receiving ABOi LRLT and were matched with six patients receiving ABO-compatible LRLT in the same period. In the ABOi group, titers of IgG and IgM isoagglutinins against the donor's blood group were determined at day 14 before the transplantation and from day 1 to 14 after the transplantation, and then twice a week for another 8 weeks. The titer results were determined as the reciprocal number of the highest serum dilution that caused macroscopical reaction. RESULTS: The patients receiving ABOi and those receiving ABO-compatible LRLT were comparable regarding the recipient's preoperative pediatric end-stage liver disease (PELD), age, gender, and technical aspects of transplantation. The median follow-up was 2.6 years (range, 1-4.5 years). At the time of operation, the mean body weight was 7.7 kg (range, 5.7-16 kg) in ABO-compatible LRLT recipients and 8.8 kg (range, 5.5-18 kg) in ABOi LRLT recipients. In each group, the median PELD score was 28 (range, 28-35), respectively. All recipients received tacrolimus plus mycophenolate mofetil-based standard immunosuppression and four ABOi transplanted patients received intravenous immunoglobulins at days 1, 3, and 5 after liver transplantation. Patient and graft survival in this group was 83%. One female patient died within 24 hours due to fulminant gram-negative sepsis. Another patient developed acute cellular rejection at the 8th postoperative day, which responded to steroid treatment. No further complications occurred. In the ABO-compatible group, patient survival was 100% and graft survival was 83%; one patient in this group received retransplantation after 4 days. During follow-up, two patients of the ABOi group had maximum alloantibody titers of four against the donor's blood group; all other patients had titers below four. CONCLUSION: ABOi LRLT seems to be safe without an escalation of immunosuppression and should be considered as an additional option to timely facilitate the transplantation.

Magnetic resonance colonography including diffusion-weighted imaging in children and adolescents with inflammatory bowel disease: do we really need intravenous contrast?

OBJECTIVES: Magnetic resonance colonography (MRC) is a well-accepted, noninvasive imaging modality for the depiction of inflammatory bowel disease. Diffusion-weighted imaging (DWI) is very helpful to display inflammatory lesions. The aim of this retrospective study was to assess whether intravenous contrast is needed to depict inflammatory lesions in bowel magnetic resonance imaging if DWI is available. MATERIALS AND METHODS: Thirty-seven patients (23 females, 14 males; mean age, 14.6 years) underwent MRC on a 1.5-T scanner (MAGNETOM Avanto; Siemens). Contrast-enhanced T1-weighted (ce-T1-w) sequences and DWI sequences in axial and coronal planes (b = 50, 500, 1000) were acquired. Two reviewers evaluated (1) DWI, (2) ce-T1-w MRC, as well as (3) DWI and ce-T1-w MRC concerning lesion conspicuity. The preferred b value was assessed. Colonoscopy was performed within 1 week, including biopsies serving as the reference standard. Sensitivities and specificities were calculated, and interobserver variability was assessed. RESULTS: Mean sensitivity and specificity of the 2 readers for the depiction of inflammatory lesions were 78.4%/100% using ce-T1-w MRC, 95.2%/100% using DWI, and 93.5%/100% combining both imaging techniques compared with colonoscopy including results of the histopathological samples. In 6 patients, inflammatory lesions were only detected by DWI; in another 6 patients, DWI detected additional lesions. The κ values for the 2 readers were excellent (k = 0.92-0.96). The preferred b value with the best detectability of the lesion was b1000 in 28 of the 30 patients (93.3%) with restricted diffusion. CONCLUSIONS: Diffusion-weighted imaging of the bowel identified inflammatory lesions with high accuracy and revealed lesions that were not detectable with ce-T1-w imaging alone. A b value of 1000 showed the best lesion detectability.