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.

Reduced Presentation of Biliary Atresia During the COVID-19 Lockdown: A Population Based Observational Study.

OBJECTIVE: The aim of this study was to assess whether there has been a change in presentations of biliary atresia (BA) in England and Wales during the first and second coronavirus disease 2019 (COVID-19) lockdowns (January-June 2020 and 2021). DESIGN: This population study assessed all confirmed cases of BA, from January 2020 to December 2021 across the 3 UK pediatric liver centers originating from England and Wales. Data was then compared to the incidence of confirmed BA cases from January to December 2017, 2018, and 2019. RESULTS: During January-June 2020 and 2021, there were only 8 and 12 presenting cases of BA in England and Wales, compared to 16, 13, and 18 for the same time periods in 2017, 2018, and 2019, respectively. This difference was significant in a two-sided t test for 2020 ( P = 0.035) but not for 2021 ( P = 0.385). There was no difference in the mean days to Kasai procedure in January-June 2020 and 2021 compared to 2017-2019; however average time to Kasai after the lockdown periods was significantly higher. CONCLUSIONS: There was a significant reduction in the presenting cases of BA during the first COVID-19 lockdown, with an increased time for BA referrals after the pandemic lockdowns were lifted in England and Wales.

Severe acute hepatitis and acute liver failure of unknown origin in children: a questionnaire-based study within 34 paediatric liver centres in 22 European countries and Israel, April 2022.

To detect potential concern about severe acute hepatitis in children, we conducted a survey among 50 ERN RARE-LIVER centres. By 26 April 2022, 34 centres, including 25 transplant centres, reported an estimated median of 3-5, 0-2 and 3-5 cases in 2021, 2020 and 2019 and a mean of 2 (range: 0-8) cases between January and April 2022 (mean in 10 large liver transplant centres: 3). Twelve centres reported suspicion of an increase, but no rise.

Sofosbuvir and Ribavirin Therapy for Children Aged 3 to <12 Years With Hepatitis C Virus Genotype 2 or 3 Infection.

Currently, the only approved hepatitis C virus (HCV) treatment for children aged <12 years is pegylated interferon plus ribavirin. In an open-label study, we evaluated the safety and efficacy of sofosbuvir plus ribavirin for 12 weeks in children aged 3 to <12 years chronically infected with genotype 2 or for 24 weeks in patients with genotype 3. Patients aged 3 to <6 years weighing <17 kg received sofosbuvir 150 mg, and patients aged 3 to <6 years weighing ≥17 kg and all patients aged 6 to <12 years received sofosbuvir 200 mg once daily. Intensive pharmacokinetic sampling conducted in each age group confirmed the appropriateness of sofosbuvir doses. For all patients, ribavirin dosing was determined by baseline weight (up to 1,400 mg/day, two divided doses). The primary efficacy endpoint was sustained virologic response 12 weeks after therapy (SVR12). Fifty-four patients were enrolled (41 aged 6 to <12 years and 13 aged 3 to <6 years). Most were treatment naïve (98%) and infected perinatally (94%). All but one patient achieved SVR12 (53/54, 98%; 95% confidence interval, 90%-100%). The patient who did not achieve SVR12 was a 4-year-old who discontinued treatment after 3 days because of "abnormal drug taste." The most commonly reported adverse events in patients aged 6 to <12 years were vomiting (32%) and headache (29%), and those in patients aged 3 to <6 years were vomiting (46%) and diarrhea (39%). One 3-year-old patient had a serious adverse event of accidental ribavirin overdose requiring hospitalization for monitoring; this patient completed treatment and achieved SVR12. Conclusion: Sofosbuvir plus ribavirin was well tolerated and highly effective in children aged 3 to <12 years with chronic HCV genotype 2 or 3 infection.

Mutation detection in cholestatic patients using microarray resequencing of ATP8B1 and ABCB11.

Background : Neonatal cholestasis is a common presentation of childhood liver diseases and can be a feature of various conditions including disorders of bile acid biogenesis and transport, various inborn errors of metabolism and perinatal infections. Some inherited metabolic diseases can be easily screened using biochemical assays, however many can only be accurately diagnosed by DNA sequencing. Fluorescent capillary Sanger sequencing (FS) is the gold standard method used by clinical laboratories for genetic diagnosis of many inherited conditions; however, it does have limitations. Recently microarray resequencing (MR) has been introduced into research and clinical practice as an alternative method for genetic diagnosis of heterogeneous conditions. In this report we compared the accuracy of mutation detection for MR with FS in a group of patients with 'low-normal' gamma glutamyl transpeptidase (gGT) cholestasis without known molecular diagnoses. Methods : 29 patient DNA samples were tested for mutations in the ATP8B1 and ABCB11 genes using both FS and MR. Other known causes of "low gGT cholestasis" such as ARC syndrome and bile acid biosynthesis disorders were excluded. Results : Mutations were identified in 13/29 samples. In 3/29 samples FS and MR gave discordant results: MR had a false positive rate of 3.4% and a false negative rate of 7%. Conclusions : The major advantage of MR over FS is that multiple genes can be screened in one experiment, allowing rapid and cost-effective diagnoses.  However, we have demonstrated that MR technology is limited in sensitivity. We therefore recommend that MR be used as an initial evaluation, with FS deployed when genetic and clinical or histopathological findings are discordant.

Combined liver-intestine grafts compared with isolated intestinal transplantation in children: a single-center experience.

BACKGROUND: Intestinal transplantation is known to be associated with a high risk of early complications and mortality. METHODS: We analyzed prospective data of 51 primary small bowel transplantations from December 1999 to August 2009 and identified perioperative factors that impact on early mortality (≤6 months after transplantation) after isolated intestinal (IITx; n=12) and combined liver-intestinal transplantation (CLITx group; n=39). RESULTS: Ten patients died during the first 6 months after transplantation, all of them in CLITx group (n=10/51, 19%). Multivariate analyses demonstrated intraoperative red blood cell transfusion greater than 70 mL/kg (P=0.019, odds ratio [OR]=13.79) and base excess 30-min after reperfusion less than -16 (P=0.001, OR=14.05), thrombocytopenia (<50,000 per dL) between day 1 and day 15 after transplantation (P=0.047, OR=5.22), and occurrence of vascular complications (P=0.003, OR=8.96) during the posttransplantation period as predictors of early mortality in CLITx group. CONCLUSION: Risk of mortality at 6 months after intestinal transplantation increased when the liver is included as combined graft. Strategies to reduce mortality such as refining selection for transplantation and early referral before the development of liver failure should be a priority.

Atypical squamous cells of undetermined significance in liquid-based cytologic specimens: results of reflex human papillomavirus testing and histologic follow-up in routine practice with comparison of interpretive and probabilistic reporting methods.

BACKGROUND: Human papillomavirus (HPV) DNA testing for high-risk types after Papanicolaou (Pap) smear interpretations of atypical squamous cells of undetermined significance (ASCUS) is a sensitive method for identifying women who harbor underlying high-grade squamous intraepithelial lesions (HSIL). To the authors' knowledge, the application of HPV testing to ASCUS smears in routine practice with comparison of probabilistic and interpretive models of cytologic reporting has not been reported. METHODS: HPV DNA testing was performed reflexively on 216 liquid-based Pap smears that initially were interpreted as ASCUS. According to the interpretive model, ASCUS interpretations were modified and reported as either low-grade squamous intraepithelial lesions (LSIL) or squamous intraepithelial lesions (SIL) when HPV positive and as reactive when HPV negative. Using the probabilistic model, ASCUS interpretations were maintained and simply reported with the HPV test result. Histologic follow-up data were obtained. RESULTS: Of the 216 women with ASCUS cytology, 142 (65.7%) were positive for high-risk HPV types. Of the 142 HPV-positive ASCUS smears, 101 (71.1%) were modified to an interpretation of LSIL (96 cases) or SIL (5 cases). Histologic follow-up of 55 of the 101 HPV-positive smears in the interpretive group and 26 of the 41 HPV-positive smears in the probabilistic group yielded similar percentages of lesions (18 lesions [32.7%] and 9 lesions [34.6%], respectively). However, there was a preponderance of low-grade lesions in the interpretive group (89%) but a nearly equal distribution of low-grade and high-grade lesions in the probabilistic group (56% and 44%, respectively); overall, 22% of the lesions were high-grade. Of the 74 HPV-negative ASCUS smears, 71 (96%) were modified to reactive and all 5 with histologic follow-up were judged as negative. CONCLUSIONS: Colposcopy with tissue studies was virtually restricted to HPV-positive cases, regardless of the reporting model used, suggesting that clinicians are basing colposcopy triage on the HPV test result rather than the definitiveness of the cytologic interpretation. This observation, the similar yield of lesions in both groups, and the significant risk of high-grade lesions argue against application of the interpretive model to HPV-tested ASCUS cases.

Transplantation for cystic fibrosis: outcome following early liver transplantation.

BACKGROUND AND AIM: Life expectancy in patients with cystic fibrosis (CF) has recently improved due to numerous factors, including a multidisciplinary approach to their management. Prolonged survival may have led to an increasing impact of liver disease on the prognosis of CF patients. The aim of this study was to assess the role of liver transplantation in patients with CF. METHODS: The factors influencing outcome in 24 patients (15 adults and nine children) with CF who have received single liver transplantation, triple heart-lung-liver transplantation (tx) or died while being assessed for triple grafting, were analyzed. RESULTS: Median age at tx in single liver recipients (13 years) was lower than in triple graft recipients (21 years) and those who died (23 years). All patients who received single liver tx made an excellent recovery, including significant improvement of their respiratory function (mean forced vital capacity (FVC) increased from 61% before transplantation to 82% of expected, 6-9 months after tx). Four out of five patients who received triple tx died (0-2 months) after operation. On the basis of our retrospective review, we propose modifications to an existing scoring system for liver tx assessment in CF by scoring additional points for elevated white blood count, bilirubin, and impaired pulmonary function. These changes will need to be evaluated prospectively to confirm their predictive value. CONCLUSIONS: Liver transplantation is effective therapy in young patients with cystic fibrosis, portal hypertension and hepatic dysfunction, and is indicated before a critical stage of deteriorating lung function is reached. In patients with both end-stage liver and lung disease, triple tx has a poor prognosis. Pre-emptive liver tx in younger patients with CF not only has a better outcome but improves lung function.