Noninvasive scores are poorly predictive of histological fibrosis in paediatric fatty liver disease.

OBJECTIVES: Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disease in children. Roughly a quarter of paediatric patients with NAFLD develop nonalcoholic steatohepatitis and fibrosis. Here, we evaluated the diagnostic accuracy of previously published noninvasive fibrosis scores to predict liver fibrosis in a large European cohort of paediatric patients with NAFLD. METHODS: The 457 patients with biopsy-proven NAFLD from 10 specialized centers were included. We assessed diagnostic accuracy for the prediction of any (F ≥ 1), moderate (F ≥ 2) or advanced (F ≥ 3) fibrosis for the AST/platelet ratio (APRI), Fibrosis 4 score (FIB-4), paediatric NAFLD fibrosis score (PNFS) and paediatric NAFLD fibrosis index (PNFI). RESULTS: Patients covered the full spectrum of fibrosis (F0: n = 103; F1: n = 230; F2: n = 78; F3: n = 44; F4: n = 2). None of the scores were able to accurately distinguish the presence of any fibrosis from no fibrosis. For the detection of moderate fibrosis, area under the receiver operating characteristic curve (AUROC) were: APRI: 0.697, FIB-4: 0.663, PNFI: 0.515, PNFS: 0.665, while for detection of advanced fibrosis AUROCs were: APRI: 0.759, FIB-4: 0.611, PNFI: 0.521, PNFS: 0.712. Fibrosis scores showed no diagnostic benefit over using ALT ≤ 50/ > 50 IU/L as a cut-off. CONCLUSIONS: Established fibrosis scores lack diagnostic accuracy to replace liver biopsy for staging of fibrosis, giving similar results as compared to using ALT alone. New diagnostic tools are needed for Noninvasive risk-stratification in paediatric NAFLD.

Biliary disease progression in childhood onset autoimmune liver disease: A 30-year follow-up into adulthood.

Background & Aims: Long-term follow-up studies of paediatric onset autoimmune liver disease (AILD) are invaluable in helping better understand the clinical course of disease. In day-to-day practice clinicians struggle with disease definitions whilst patients and parents lack clear prognostic information. Methods: The clinical progression of 159 patients with childhood onset AILD between June 1990 and December 2013 was reviewed, capturing data up to adulthood (ending May 2021). Results: Presentation with autoimmune hepatitis (AIH) was dominant (n = 119); biliary presentations accounted for 25%. During follow up, biliary disease progression confirmed by cholangiography and/or liver histology was observed frequently: 19.8% (20/101) patients with childhood onset AIH type 1 (AIH-1) developed biliary features by adulthood and of these 50% phenotypically transitioned to primary sclerosing cholangitis (PSC); the remaining transitioned to an overlap disease phenotype. No patients with AIH type 2 developed biliary progression. Two-thirds of patients with overlap features (14/21) in childhood had phenotypically progressed to PSC by adulthood. Approximately 43% (6/14) of AIH-1 patients requiring a liver transplant in adulthood had explant evidence of biliary disease compared with 11% (1/9) in childhood, whereas 35.7% (5/14) of patients had histology diagnostic of PSC in their explant liver and 7.1% (1/14) had overlap features. All patients with biliary phenotypes (PSC, autoimmune sclerosing cholangitis, overlap) who required a transplant (n = 18) were found to have explant histology consistent with PSC. Twelve of 14 patients with biliary progression developed ulcerative colitis during follow-up with 92% progressing to PSC. Conclusions: Three decades of follow-up demonstrated how children presenting with AILD had a significant risk of clinical transformation to PSC. Biliary progression was significantly associated with the development of inflammatory bowel disease. Impact and implications: Childhood onset autoimmune liver disease remains very impactful for patients and families. Disease nomenclature can however be confusing. Long-term follow up studies as children become adults is important to help understand how and why disease behaves over time. Understanding more about the long-term course of childhood autoimmune liver disease will help patients, families and doctors striving to improve care and reduce poor clinical outcomes. We followed over 150 patients with childhood onset autoimmune liver diseases into adulthood. We found that amongst patients with classical autoimmune hepatitis, 1 in 5 developed biliary disease over time, mostly consisting of primary sclerosing cholangitis. This was associated with developing inflammatory bowel disease. Our study design was retrospective and has relevant limitations. Defining phenotypes of autoimmune liver diseases is difficult and there is insufficient consensus, especially between adult and childhood physicians. Our data confirms the critical importance of careful long-term follow-up of patients, including safe transition to adult care, as well as robustly demonstrates, using real-world data, how disease nature can change over time. Our study affirms the need for investment in prospective cohort studies.

Viral Hepatitis Necessitating Liver Transplantation in Children.

Viral hepatitis accounts for a significant global disease burden and mortality, both in children and adults. There are significant differences in the viral etiology, epidemiology, and complications in children worldwide. Children of all ages may have devastating complications with a significant risk of mortality and long-term morbidity because of viral hepatitis. Liver transplantation is the only curative option for pediatric patients with end-stage liver disease, hepatocellular carcinoma, or acute liver failure because of viral hepatitis. The introduction of universal vaccination for hepatitis B across the world and hepatitis A in some countries had led to significant changes in the incidence of disease and the need for liver transplantation for the complications of viral hepatitis in children. The development of effective treatment with directly acting antiviral agents for hepatitis C has already transformed outcomes in adults and children and reduced the need for liver transplantation. Although newer therapy for hepatitis B is being evaluated in adults, current therapy for children is not curative, indicating the need for lifelong therapy and potential necessity for liver transplantation. The recent epidemic of acute hepatitis in children across the world has highlighted the importance of understanding the etiology of unusual causes for acute liver failure and the urgent need for liver transplantation.

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.

Paediatric research sets new standards for therapy in paediatric and adult cholestasis.

Children with Alagille syndrome and progressive familial intrahepatic cholestasis (PFIC) experience debilitating pruritus, for which there have been few effective treatment options. In the past 2 years, the ileal bile acid transporter (IBAT) inhibitors maralixibat and odevixibat have been approved for the management of cholestatic pruritus in these individuals, representing an important step forward in improving their quality of life. Emerging data suggest these drugs might also improve event-free survival, therefore potentially altering the typical disease course currently seen in these disorders. This Review will discuss how genetic advances have clarified the molecular basis of cholestatic disorders, facilitating the development of new therapeutic options that have only been evaluated in children. We focus specifically on the newly licensed IBAT inhibitors for patients with Alagille syndrome and PFIC and explore the next steps for these drugs in relation to other paediatric and adult cholestatic disorders, recognising that they have the potential to benefit a wider group of patients with gastrointestinal and liver disease.

Structural and non-coding variants increase the diagnostic yield of clinical whole genome sequencing for rare diseases.

BACKGROUND: Whole genome sequencing is increasingly being used for the diagnosis of patients with rare diseases. However, the diagnostic yields of many studies, particularly those conducted in a healthcare setting, are often disappointingly low, at 25-30%. This is in part because although entire genomes are sequenced, analysis is often confined to in silico gene panels or coding regions of the genome. METHODS: We undertook WGS on a cohort of 122 unrelated rare disease patients and their relatives (300 genomes) who had been pre-screened by gene panels or arrays. Patients were recruited from a broad spectrum of clinical specialties. We applied a bioinformatics pipeline that would allow comprehensive analysis of all variant types. We combined established bioinformatics tools for phenotypic and genomic analysis with our novel algorithms (SVRare, ALTSPLICE and GREEN-DB) to detect and annotate structural, splice site and non-coding variants. RESULTS: Our diagnostic yield was 43/122 cases (35%), although 47/122 cases (39%) were considered solved when considering novel candidate genes with supporting functional data into account. Structural, splice site and deep intronic variants contributed to 20/47 (43%) of our solved cases. Five genes that are novel, or were novel at the time of discovery, were identified, whilst a further three genes are putative novel disease genes with evidence of causality. We identified variants of uncertain significance in a further fourteen candidate genes. The phenotypic spectrum associated with RMND1 was expanded to include polymicrogyria. Two patients with secondary findings in FBN1 and KCNQ1 were confirmed to have previously unidentified Marfan and long QT syndromes, respectively, and were referred for further clinical interventions. Clinical diagnoses were changed in six patients and treatment adjustments made for eight individuals, which for five patients was considered life-saving. CONCLUSIONS: Genome sequencing is increasingly being considered as a first-line genetic test in routine clinical settings and can make a substantial contribution to rapidly identifying a causal aetiology for many patients, shortening their diagnostic odyssey. We have demonstrated that structural, splice site and intronic variants make a significant contribution to diagnostic yield and that comprehensive analysis of the entire genome is essential to maximise the value of clinical genome sequencing.

Paediatric acute hepatitis of unknown aetiology: a national investigation and adenoviraemia case-control study in the UK.

BACKGROUND: An increase in acute severe hepatitis of unknown aetiology in previously healthy children in the UK in March, 2022, triggered global case-finding. We aimed to describe UK epidemiological investigations of cases and their possible causes. METHODS: We actively surveilled unexplained paediatric acute hepatitis (transaminase >500 international units per litre) in children younger than 16 years presenting since Jan 1, 2022, through notifications from paediatricians, microbiologists, and paediatric liver units; we collected demographic, clinical, and exposure information. Then, we did a case-control study to investigate the association between adenoviraemia and other viruses and case-status using multivariable Firth penalised logistic regression. Cases aged 1-10 years and tested for adenovirus were included and compared with controls (ie, children admitted to hospital with an acute non-hepatitis illness who had residual blood samples collected between Jan 1 and May 28, 2022, and without known laboratory-confirmed diagnosis or previous adenovirus testing). Controls were frequency-matched on sex, age band, sample months, and nation or supra-region with randomised selection. We explored temporal associations between frequency of circulating viruses identified through routine laboratory pathogen surveillance and occurrence of cases by linear regression. SARS-CoV-2 seropositivity of cases was examined against residual serum from age-matched clinical comparison groups. FINDINGS: Between Jan 1 and July 4, 2022, 274 cases were identified (median age 3 years [IQR 2-5]). 131 (48%) participants were male, 142 (52%) were female, and one (<1%) participant had sex data unknown. Jaundice (195 [83%] of 235) and gastrointestinal symptoms (202 [91%] of 222) were common. 15 (5%) children required liver transplantation and none died. Adenovirus was detected in 172 (68%) of 252 participants tested, regardless of sample type; 137 (63%) of 218 samples were positive for adenovirus in the blood. For cases that were successfully genotyped, 58 (81%) of 72 had Ad41F, and 57 were identified as positive via blood samples (six of these were among participants who had undergone a transplant). In the case-control analysis, adenoviraemia was associated with hepatitis case-status (adjusted OR 37·4 [95% CI 15·5-90·3]). Increases in the detection of adenovirus from faecal samples, but not other infectious agents, in routine laboratory pathogen surveillance correlated with hepatitis cases 4 weeks later, which independently suggested an association (ß 0·06 [95% CI 0·02-0·11]). No association was identified for SARS-CoV-2 antibody seropositivity. INTERPRETATION: We observed an association between adenovirus 41F viraemia and paediatric acute hepatitis. These results can inform diagnostic testing recommendations, clinical management, and exploratory in vitro or clinical studies of paediatric acute hepatitis of unknown aetiology. The role of potential co-factors, including other viruses and host susceptibility, requires further investigation. FUNDING: None.

Biliary atresia is associated with polygenic susceptibility in ciliogenesis and planar polarity effector genes.

BACKGROUND & AIMS: Biliary atresia (BA) is poorly understood and leads to liver transplantation (LT), with the requirement for and associated risks of lifelong immunosuppression, in most children. We performed a genome-wide association study (GWAS) to determine the genetic basis of BA. METHODS: We performed a GWAS in 811 European BA cases treated with LT in US, Canadian and UK centers, and 4,654 genetically matched controls. Whole-genome sequencing of 100 cases evaluated synthetic association with rare variants. Functional studies included whole liver transcriptome analysis of 64 BA cases and perturbations in experimental models. RESULTS: A GWAS of common single nucleotide polymorphisms (SNPs), i.e. allele frequencies >1%, identified intronic SNPs rs6446628 in AFAP1 with genome-wide significance (p = 3.93E-8) and rs34599046 in TUSC3 at sub-threshold genome-wide significance (p = 1.34E-7), both supported by credible peaks of neighboring SNPs. Like other previously reported BA-associated genes, AFAP1 and TUSC3 are ciliogenesis and planar polarity effectors (CPLANE). In gene-set-based GWAS, BA was associated with 6,005 SNPs in 102 CPLANE genes (p = 5.84E-15). Compared with non-CPLANE genes, more CPLANE genes harbored rare variants (allele frequency <1%) that were assigned Human Phenotype Ontology terms related to hepatobiliary anomalies by predictive algorithms, 87% vs. 40%, p <0.0001. Rare variants were present in multiple genes distinct from those with BA-associated common variants in most BA cases. AFAP1 and TUSC3 knockdown blocked ciliogenesis in mouse tracheal cells. Inhibition of ciliogenesis caused biliary dysgenesis in zebrafish. AFAP1 and TUSC3 were expressed in fetal liver organoids, as well as fetal and BA livers, but not in normal or disease-control livers. Integrative analysis of BA-associated variants and liver transcripts revealed abnormal vasculogenesis and epithelial tube formation, explaining portal vein anomalies that co-exist with BA. CONCLUSIONS: BA is associated with polygenic susceptibility in CPLANE genes. Rare variants contribute to polygenic risk in vulnerable pathways via unique genes. IMPACT AND IMPLICATIONS: Liver transplantation is needed to cure most children born with biliary atresia, a poorly understood rare disease. Transplant immunosuppression increases the likelihood of life-threatening infections and cancers. To improve care by preventing this disease and its progression to transplantation, we examined its genetic basis. We find that this disease is associated with both common and rare mutations in highly specialized genes which maintain normal communication and movement of cells, and their organization into bile ducts and blood vessels during early development of the human embryo. Because defects in these genes also cause other birth defects, our findings could lead to preventive strategies to lower the incidence of biliary atresia and potentially other birth defects.

Addressing extreme size mismatch in pediatric intestinal transplantation: Outcomes of intestinal length reduction.

BACKGROUND: Bench liver reduction, with or without intestinal length reduction (LR) (coupled with delayed closure and abdominal wall prostheses), has been a strategy adopted by our program for small children due to the limited availability of size-matched donors. This report describes the short, medium, and long-term outcomes of this graft reduction strategy. METHODS: A single-center, retrospective analysis of children that underwent intestinal transplantation (April 1993 to December 2020) was performed. Patients were grouped according to whether they received an intestinal graft of full length (FL) or following LR. RESULTS: Overall, 105 intestinal transplants were performed. The LR group (n = 10) was younger (14.5 months vs. 40.0 months, p = .012) and smaller (8.7 kg vs. 13.0 kg, p = .032) compared to the FL group (n = 95). Similar abdominal closure rates were achieved after LR, without any increase in abdominal compartment syndrome (1/10 vs. 7/95, p = .806). The 90-day graft and patient survival were similar (9/10, 90% vs. 83/95, 86%; p = .810). Medium and long-term graft survival at 1 year (8/10, 80% vs. 65/90, 71%; p = .599), and 5 years (5/10, 50% vs. 42/84, 50%; p = 1.00) was similar. CONCLUSION: LR of intestinal grafts appears to be a safe strategy for infants and small children requiring intestinal transplantation. This technique should be considered in the situation of significant size mismatch of intestine containing grafts.

Long-term Outcome of Asymptomatic Patients With Graft Fibrosis in Protocol Biopsies After Pediatric Liver Transplantation.

BACKGROUND: The histological prevalence of allograft fibrosis in asymptomatic children after liver transplantation (LT) is well documented. However, long-term graft and patient survival remain unclear. This retrospective multicenter study aims to determine the prevalence of allograft fibrosis and analyze the long-term outcome for patients transplanted in childhood. METHODS: We reviewed clinical data of children who had undergone 10-y protocol liver biopsies. We excluded patients with autoimmune hepatitis, primary sclerosing cholangitis, hepatitis B or C, and retransplantation. In total, 494 patients transplanted in childhood across 12 international transplant centers were included. We evaluated the development of fibrosis by comparing the results with biopsies obtained 5 and 15 y post-LT. Histological findings were correlated with graft and patient survival up to 20 y post-LT. RESULTS: In the 10-y biopsies, periportal or pericentral fibrosis was observed in 253 patients (51%), 87 (18%) had bridging fibrosis, 30 (6%) had cirrhosis, and 124 (25%) had no fibrosis. The prevalence and stage of graft fibrosis significantly progressed from 5 to 10 y. At 10 y, the severity of fibrosis correlated significantly with inflammation. Patients with graft cirrhosis in the 10-y biopsy were more likely to die or require retransplantation subsequently ( P = 0.027). CONCLUSIONS: At 10 y post-LT, most patients transplanted in childhood developed fibrosis, based on the protocol liver biopsies. Although mild-to-moderate graft fibrosis did not largely affect patient or graft survival up to 20 y post-LT, this progressive fibrosis finding has substantial implications for developing cirrhosis and portal hypertension in adult care.

Case report: Acute liver failure in children and the human herpes virus 6-? A factor in the recent epidemic.

The 2022 worldwide epidemic of acute hepatitis and liver failure in young children has led to a focus on unusual causes for childhood acute hepatitis. In the UK epidemic, human herpes virus subtype 6B (HHV-6B) was detected along with adenovirus subtype-41F in severely affected children, especially in those requiring liver transplantation (LT). The lifting of COVID lock-down measures has coincided with the rise in these common childhood infections with a higher than expected rate of systemic complications. The sudden exposure of young children to common childhood infections from which they were protected during the pandemic may have induced an abnormal immune mediated response potentiated by multiple pathogen exposure. Primary HHV-6 infection is one such common childhood infection. Classically known as Roseola infantum due to the appearance of a widespread erythematous rash on fever subsidence (exanthema subitem), it has a peak incidence of 6-12 months of age and almost all children will have been infected by age 2. It is the virus most frequently associated with febrile convulsions but the more serious complications of hepatitis and liver failure are rare. We report on the historic cases of three female infants who had suspected primary HHV-6B infection, acute hepatitis and rapid progression to acute liver failure (ALF) requiring LT. Appearances of their native liver were identical to those described in children in the recent hepatitis epidemic. Deteriorating clinical trajectories of recurrent graft hepatitis and rejection-like episodes followed and all three succumbed to graft failure with HHV-6B detected posthumously in their liver allografts. Our case series and the serious complications observed with the recent rise in common childhood infections is a reminder that these routinely encountered pathogens can be deadly especially in the young immunologically untrained. We advocate for HHV-6 to be screened for routinely in children with acute hepatitis and the use of effective HHV-6 anti-viral prophylaxis to prevent recurrence post-transplant.

Etiology and Outcome of Adult and Pediatric Acute Liver Failure in Europe.

Acute liver failure (ALF) is rare but life-threatening. Common causes include intoxications, infections, and metabolic disorders. Indeterminate etiology is still frequent. No systematic data on incidence, causes, and outcome of ALF across Europe are available. Via an online survey we reached out to European Reference Network Centers on rare liver diseases. Numbers and etiology of ALF cases during 2020 were retrieved and diagnostic and treatment availabilities assessed. In total, 455 cases (306 adult, 149 pediatric) were reported from 36 centers from 20 countries. Intoxication was the most common cause in adult and pediatric care. The number of cases with indeterminate etiology is low. Diagnostic tools and specific treatment options are broadly available within this network. This is the first approach to report on etiology and outcome of ALF in the pediatric and adult population in Europe. High diagnostic yield and standard of care reflects the expert status of involved centers.

Biliary Atresia in Adolescence and Adult Life: Medical, Surgical and Psychological Aspects.

Prior to 1955, when Morio Kasai first performed the hepatic portoenterostomy procedure which now bears his name, Biliary atresia (BA) was a uniformly fatal disease. Both the Kasai procedure and liver transplantation have markedly improved the outlook for infants with this condition. Although long-term survival with native liver occurs in the minority, survival rates post liver transplantation are high. Most young people born with BA will now survive into adulthood but their ongoing requirements for health care will necessitate their transition from a family-centred paediatric service to a patient-centred adult service. Despite a rapid growth in transition services over recent years and progress in transitional care, transition from paediatric to adult services is still a risk for poor clinical and psychosocial outcomes and increased health care costs. Adult hepatologists should be aware of the clinical management and complications of biliary atresia and the long-term consequences of liver transplantation in childhood. Survivors of childhood illness require a different approach to that for young adults presenting after 18 years of age with careful consideration of their emotional, social, and sexual health. They need to understand the risks of non-adherence, both for clinic appointments and medication, as well as the implications for graft loss. Developing adequate transitional care for these young people is based on effective collaboration at the paediatric-adult interface and is a major challenge for paediatric and adult providers alike in the 21st century. This entails education for patients and adult physicians in order to familiarise them with the long-term complications, in particular for those surviving with their native liver and the timing of consideration of liver transplantation if required. This article focusses on the outcome for children with biliary atresia who survive into adolescence and adult life with considerations on their current management and prognosis.

Genotype-phenotype relationships of truncating mutations, p.E297G and p.D482G in bile salt export pump deficiency.

Background & Aims: Bile salt export pump (BSEP) deficiency frequently necessitates liver transplantation in childhood. In contrast to two predicted protein truncating mutations (PPTMs), homozygous p.D482G or p.E297G mutations are associated with relatively mild phenotypes, responsive to surgical interruption of the enterohepatic circulation (siEHC). The phenotype of patients with a compound heterozygous genotype of one p.D482G or p.E297G mutation and one PPTM has remained unclear. We aimed to assess their genotype-phenotype relationship. Methods: From the NAPPED database, we selected patients with homozygous p.D482G or p.E297G mutations (BSEP1/1; n = 31), with one p.D482G or p.E297G, and one PPTM (BSEP1/3; n = 30), and with two PPTMs (BSEP3/3; n = 77). We compared clinical presentation, native liver survival (NLS), and the effect of siEHC on NLS. Results: The groups had a similar median age at presentation (0.7-1.3 years). Overall NLS at age 10 years was 21% in BSEP1/3 vs. 75% in BSEP1/1 and 23% in BSEP3/3 (p <0.001). Without siEHC, NLS in the BSEP1/3 group was similar to that in BSEP3/3, but considerably lower than in BSEP1/1 (at age 10 years: 38%, 30%, and 71%, respectively; p = 0.003). After siEHC, BSEP1/3 and BSEP3/3 were associated with similarly low NLS, while NLS was much higher in BSEP1/1 (10 years after siEHC, 27%, 14%, and 92%, respectively; p <0.001). Conclusions: Individuals with BSEP deficiency with one p.E297G or p.D482G mutation and one PPTM have a similarly severe disease course and low responsiveness to siEHC as those with two PPTMs. This identifies a considerable subgroup of patients who are unlikely to benefit from interruption of the enterohepatic circulation by either surgical or ileal bile acid transporter inhibitor treatment. Impact and implications: This manuscript defines the clinical features and prognosis of individuals with BSEP deficiency involving the combination of one relatively mild and one very severe BSEP deficiency mutation. Until now, it had always been assumed that the mild mutation would be enough to ensure a relatively good prognosis. However, our manuscript shows that the prognosis of these patients is just as poor as that of patients with two severe mutations. They do not respond to biliary diversion surgery and will likely not respond to the new IBAT (ileal bile acid transporter) inhibitors, which have recently been approved for use in BSEP deficiency.

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-ß, 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.

Common mechanisms in pediatric acute liver failure.

Acute liver failure (ALF) is a rare but potentially fatal disease in children. The etiology is multifactorial, including infection, autoimmune, and genetic disorders, as well as indeterminate hepatitis, which has a higher requirement for liver transplantation. Activation of the innate and adaptive immune systems leads to hepatocyte-specific injury which is mitigated by T regulatory cell activation. Recovery of the native liver depends on activation of apoptotic and regenerative pathways, including the integrated stress response (ISR; e.g., PERK), p53, and HNF4α. Loss-of-function mutations in these pathways cause recurrent ALF in response to non-hepatotropic viruses. Deeper understanding of these mechanisms will lead to improved diagnosis, management, and outcomes for pediatric ALF.

Molecular characterisation of pancreatic ductal adenocarcinoma with NTRK fusions and review of the literature.

AIMS: The majority of pancreatic ductal adenocarcinomas (PDACs) harbour oncogenic mutations in KRAS with variants in TP53, CDKN2A and SMAD4 also prevalent. The presence of oncogenic fusions including NTRK fusions are rare but important to identify. Here we ascertain the prevalence of NTRK fusions and document their genomic characteristics in a large series of PDAC. METHODS: Whole genome sequencing and RNAseq were performed on a series of patients with resected or locally advanced/metastatic PDAC collected between 2008 and 2020 at a single institution. A subset of specimens underwent immunohistochemistry (IHC) analysis. Clinical and molecular characterisation and IHC sensitivity and specificity were evaluated. RESULTS: 400 patients were included (resected n=167; locally advanced/metastatic n=233). Three patients were identified as harbouring an NTRK fusion, two EML4-NTRK3 (KRAS-WT) and a single novel KANK1-NTRK3 fusion. The latter occurring in the presence of a subclonal KRAS mutation. Typical PDAC drivers were present including mutations in TP53 and CDKN2A. Substitution base signatures and tumour mutational burden were similar to typical PDAC. The prevalence of NTRK fusions was 0.8% (3/400), while in KRAS wild-type tumours, it was 6.25% (2/32). DNA prediction alone documented six false-positive cases. RNA analysis correctly identified the in-frame fusion transcripts. IHC analysis was negative in the KANK1-NTRK3 fusion but positive in a EML4-NTRK3 case, highlighting lower sensitivity of IHC. CONCLUSION: NTRK fusions are rare; however, with emerging therapeutic options targeting these fusions, detection is vital. Reflex testing for KRAS mutations and subsequent RNA-based screening could help identify these cases in PDAC.

Long-term clinical and socioeconomic outcomes of children with biliary atresia.

Background: Biliary atresia (BA) is rare liver disease of unknown etiology, and is a major indication for liver transplant (LT). Previous data indicate improved outcomes with early referral for Kasai portoenterostomy (KPE). Objective: Evaluate the long-term outcomes in BA, with particular focus on those transitioned to adult care with native livers. Subjects and Methods: Patients with BA treated between1980 and 2012 were identified. Data were collected from the time of referral, transition to adult care, and the most recent clinic notes, from which patient and native liver survival were calculated. Results: Four hundred and fifty-four patients with BA were identified, who were followed up for median of 16.4 years from birth; 74 died (41 of whom had a LT), giving a 20-year survival rate of 83.6%. Two hundred and seventy-two patients received an LT, with the median native liver survival being 35 months. Of patients who transitioned to adult care, 54 of 180 (30.0%) retained their native liver. Of these, 72% (39 of 54) had evidence of chronic liver disease at transition, of whom 8 were subsequently lost to follow-up, 9 were transplanted, and 22 remained stable with compensated liver disease. Of the 15 of 54 patients (28%) with no evidence of chronic disease in their native liver disease at transition, 3 were subsequently lost to follow-up; none received transplants, although 3 patients developed new-onset liver disease. All patients transitioned to adult care completed secondary school education (N = 180), with 49% having attended college/university and 87% being in employment or education at the last follow-up. Of female patients, 34% had at least one pregnancy (27 children in 21 women), while 22% of males had fathered a child. Conclusion: Long-term outcomes in BA are good, with patients surviving into adult life. Progression of chronic liver disease and associated morbidity is common in those who retained their native livers, suggesting that these patients require monitoring of liver disease throughout adult life, and early recognition of the need for LT.

hENT1 Expression Predicts Response to Gemcitabine and Nab-Paclitaxel in Advanced Pancreatic Ductal Adenocarcinoma.

PURPOSE: Modified FOLFIRINOX (mFFX) and gemcitabine/nab-paclitaxel (GnP) remain standard first-line options for patients with advanced pancreatic ductal adenocarcinoma (PDAC). Human equilibrative nucleoside transporter 1 (hENT1) was hypothesized to be a biomarker of gemcitabine in the adjuvant setting, with conflicting results. In this study, we explore hENT1 mRNA expression as a predictive biomarker in advanced PDAC. EXPERIMENTAL DESIGN: COMPASS was a prospective observational trial of patients with advanced PDAC. A biopsy was required prior to initiating chemotherapy, as determined by treating physician. Biopsies underwent laser capture microdissection prior to whole genome and RNA sequencing. The cut-off thresholds for hENT1 expression were determined using the maximal χ2 statistic. RESULTS: 253 patients were included in the analyses with a median follow-up of 32 months, with 138 patients receiving mFFX and 92 receiving GnP. In the intention to treat population, median overall survival (OS) was 10.0 months in hENT1high versus 7.9 months in hENT1low (P = 0.02). In patients receiving mFFX, there was no difference in overall response rate (ORR; 35% vs. 28%, P = 0.56) or median OS (10.6 vs. 10.5 months, P = 0.45). However, in patients treated with GnP, the ORR was significantly higher in hENT1high compared with hENT1low tumors (43% vs. 21%, P = 0.038). Median OS in this GnP-treated cohort was 10.6 months in hENT1high versus 6.7 months hENT1low (P < 0.001). In an interaction analysis, hENT1 was predictive of treatment response to GnP (interaction P = 0.002). CONCLUSIONS: In advanced PDAC, hENT1 mRNA expression predicts ORR and OS in patients receiving GnP.