Comparison of the Lipidomic Signature of Fatty Liver in Children and Adults: A Cross-Sectional Study.

OBJECTIVE: Non-alcoholic fatty liver disease (NAFLD) is an increasingly common condition in children characterised by insulin resistance and altered lipid metabolism. Affected patients are at increased risk of cardiovascular disease (CVD) and children with NAFLD are likely to be at risk of premature cardiac events. Evaluation of the plasma lipid profile of children with NAFLD offers the opportunity to investigate these perturbations and understand how closely they mimic the changes seen in adults with cardiometabolic disease. METHODS: We performed untargeted liquid chromatography-mass spectrometry (LC-MS) plasma lipidomics on 287 children: 19 lean controls, 146 from an obese cohort, and 122 NAFLD cases who had undergone liver biopsy. Associations between lipid species and liver histology were assessed using regression adjusted for age and sex. Results were then replicated using data from 9500 adults with metabolic phenotyping. RESULTS: More severe paediatric NAFLD was associated with lower levels of long chain, polyunsaturated phosphatidylcholines (pC) and triglycerides (TG). Similar trends in pC and TG chain length and saturation were seen in adults with hepatic steatosis; however, many of the specific lipids associated with NAFLD differed between children and adults. Five lipids replicated in adults (including PC(36:4)) have been directly linked to death and cardiometabolic disease, as well as indirectly via genetic variants. CONCLUSION: These findings suggest that, whilst similar pathways of lipid metabolism are perturbed in paediatric NAFLD as in cardiometabolic disease in adults, the specific lipid signature in children is different.JPM is supported by a Wellcome Trust fellowship (216329/Z/19/Z), a European Society for Paediatric Research (ESPR) Young Investigator Award, and a Children’s Liver Disease Foundation Grant. EU-PNAFLD Registry is supported by a European Association for Study of the Liver (EASL) Registry Grant. MZ is supported by a New Investigator Research Grant from the MRC (MR/T001917/1). BK is supported by grants from Van den Broek Lohman Foundation, Virtutis Opus Foundation and For Wishdom Foundation. SF, SGS & AK are supported by the BBSRC (BB/M027252/1 & BB/P028195/1), BJJ & AK are supported by the National Institute for Health Research (NIHR146281)

Clinical, biochemical, cellular and molecular characterization of mitochondrial DNA depletion syndrome due to novel mutations in the MPV17 gene

Mitochondrial DNA (mtDNA) depletion syndromes (MDS) are severe autosomal recessive disorders associated with decreased mtDNA copy number in clinically affected tissues. The hepatocerebral form (mtDNA depletion in liver and brain) has been associated with mutations in the POLG, PEO1 (Twinkle), DGUOK and MPV17 genes, the latter encoding a mitochondrial inner membrane protein of unknown function. The aims of this study were to clarify further the clinical, biochemical, cellular and molecular genetic features associated with MDS due to MPV17 gene mutations. We identified 12 pathogenic mutations in the MPV17 gene, of which 11 are novel, in 17 patients from 12 families. All patients manifested liver disease. Poor feeding, hypoglycaemia, raised serum lactate, hypotonia and faltering growth were common presenting features. mtDNA depletion in liver was demonstrated in all seven cases where liver tissue was available. Mosaic mtDNA depletion was found in primary fibroblasts by PicoGreen staining. These results confirm that MPV17 mutations are an important cause of hepatocerebral mtDNA depletion syndrome, and provide the first demonstration of mosaic mtDNA depletion in human MPV17 mutant fibroblast cultures. We found that a severe clinical phenotype was associated with profound tissue-specific mtDNA depletion in liver, and, in some cases, mosaic mtDNA depletion in fibroblasts

Acute on chronic liver failure: A 20-year retrospective review of a tertiary paediatric liver center.

AIM Acute on Chronic Liver Failure (ACLF) is an acute deterioration of pre-existing chronic liver disease related to a precipitating event. We characterised paediatric ACLF at Birmingham Children's Hospital (BCH) utilising European Association of Liver Disease CLIF criteria: including prevalence, triggers and outcomes. METHODS All BCH patients from 2000-2020 with CLD who underwent initial liver transplant or died on the transplant waiting list or whilst too unwell to be listed were reviewed. RESULTS From 2000-2020 24 (4%) children with ACLF were identified. Death occurred in 18 (75%). Transplant occurred in 9 (36%), 3 of which died. ACLF triggers were sepsis organism negative 11(46%), sepsis organism positive 8(33%) and GI bleed 5 (17%). Bilirubin at time of transplant/death in those with ACLF who lived compared to those who died was 529 umol/L (381) vs. 665 (210) (p=0.38), Creatinine 138 umol/L (147) vs. 67 (46) (p=0.41), PT 33 sec (14) vs. (32 (15) (p=0.72), Grade 3,4 hepatic encephalopathy 1 (17%) vs. 10 (56%) (p=0.17), Vasopressor use 1 (17%) vs. 17 (94%) (p=0.001) and Ventilation 3 (50%) vs. 17 (94%) (p=0.035). CONCLUSION ACLF whilst infrequent has high rates of mortality. Use of vasopressors and ventilation is more frequent in those who die from ACLF

Acute-on-chronic liver failure: A 20-year retrospective review of a tertiary paediatric liver centre.

AIM Acute-on-chronic liver failure (ACLF) is an acute deterioration of pre-existing chronic liver disease related to a precipitating event. We characterised paediatric ACLF at Birmingham Children's Hospital (BCH) utilising European Association of Liver Disease CLIF criteria, including prevalence, triggers and outcomes. METHODS All BCH patients from 2000 to 2020 with CLD who underwent initial liver transplant or died on the transplant waiting list or whilst too unwell to be listed were reviewed. RESULTS From 2000 to 2020, 24 (4%) children with ACLF were identified. Death occurred in 18 (75%). Transplant occurred in 9 (36%), 3 of which died. ACLF triggers were sepsis organism negative 11 (46%), sepsis organism positive 8 (33%) and GI bleed 5 (17%). Bilirubin at the time of transplant/death in those with ACLF who lived compared with those who died was 529 umol/L (381) versus 665 (210) (p=0.38), creatinine 138 umol/L (147) versus 67 (46) (p=0.41), PT 33 sec (14) versus (32 (15) (p = 0.72), Grade 3, 4 hepatic encephalopathy 1 (17%) versus 10 (56%) (p = 0.17), vasopressor use 1 (17%) versus 17 (94%) (p = 0.001) and ventilation 3 (50%) versus 17 (94%) (p = 0.035). CONCLUSION Acute-on-chronic liver failure whilst infrequent has high rates of mortality. The use of vasopressors and ventilation is more frequent in those who die from ACLF

European paediatric non-alcoholic fatty liver disease registry (EU-PNAFLD): Design and rationale.

Non-alcoholic fatty liver disease (NAFLD) is the most common liver disorder in children and has the potential to progress to advanced fibrosis/cirrhosis, end-stage liver disease and hepatocellular carcinoma. However, the natural history of the condition is poorly understood and there are no approved treatments. The European Paediatric Non-Alcoholic Fatty Liver Disease Registry (EU-PNAFLD) is a multi-centre registry of paediatric NAFLD that will serve as a prospective, observational, natural history study and provide a tractable back-bone to support recruitment into subsequent interventional trials. Collection of samples into a bio-repository will facilitate translational studies, including genome sequencing and metabolomics. EU-PNAFLD will work closely alongside the existing adult European NAFLD Registry to obtain data on clinical outcomes after 20-30 years. Through an international, well-characterised large-scale cohort, EU-PNAFLD will address the key questions in paediatric NAFLD and benefit patients with the condition.Funding from institutional grants to SOR & DBS from Wellcome Trust UK, to VN from the European Association for the Study of the Liver (EASL), and to JPM from the Children’'s Liver Disease Foundation (CLDF). QMA is supported by the EPoS (Elucidating Pathways of Steatohepatitis) consortium funded by the Horizon 2020 Framework Program of the European Union under Grant Agreement 634413, an EASL Registry Grant and the Newcastle NIHR Biomedical Research Centre