Genomic investigations of unexplained acute hepatitis in children.

Since its first identification in Scotland, over 1,000 cases of unexplained paediatric hepatitis in children have been reported worldwide, including 278 cases in the UK1. Here we report an investigation of 38 cases, 66 age-matched immunocompetent controls and 21 immunocompromised comparator participants, using a combination of genomic, transcriptomic, proteomic and immunohistochemical methods. We detected high levels of adeno-associated virus 2 (AAV2) DNA in the liver, blood, plasma or stool from 27 of 28 cases. We found low levels of adenovirus (HAdV) and human herpesvirus 6B (HHV-6B) in 23 of 31 and 16 of 23, respectively, of the cases tested. By contrast, AAV2 was infrequently detected and at low titre in the blood or the liver from control children with HAdV, even when profoundly immunosuppressed. AAV2, HAdV and HHV-6 phylogeny excluded the emergence of novel strains in cases. Histological analyses of explanted livers showed enrichment for T cells and B lineage cells. Proteomic comparison of liver tissue from cases and healthy controls identified increased expression of HLA class 2, immunoglobulin variable regions and complement proteins. HAdV and AAV2 proteins were not detected in the livers. Instead, we identified AAV2 DNA complexes reflecting both HAdV-mediated and HHV-6B-mediated replication. We hypothesize that high levels of abnormal AAV2 replication products aided by HAdV and, in severe cases, HHV-6B may have triggered immune-mediated hepatic disease in genetically and immunologically predisposed children.

Adeno-associated virus type 2 in US children with acute severe hepatitis.

As of August 2022, clusters of acute severe hepatitis of unknown aetiology in children have been reported from 35 countries, including the USA1,2. Previous studies have found human adenoviruses (HAdVs) in the blood from patients in Europe and the USA3-7, although it is unclear whether this virus is causative. Here we used PCR testing, viral enrichment-based sequencing and agnostic metagenomic sequencing to analyse samples from 16 HAdV-positive cases from 1 October 2021 to 22 May 2022, in parallel with 113 controls. In blood from 14 cases, adeno-associated virus type 2 (AAV2) sequences were detected in 93% (13 of 14), compared to 4 (3.5%) of 113 controls (P < 0.001) and to 0 of 30 patients with hepatitis of defined aetiology (P < 0.001). In controls, HAdV type 41 was detected in blood from 9 (39.1%) of the 23 patients with acute gastroenteritis (without hepatitis), including 8 of 9 patients with positive stool HAdV testing, but co-infection with AAV2 was observed in only 3 (13.0%) of these 23 patients versus 93% of cases (P < 0.001). Co-infections by Epstein-Barr virus, human herpesvirus 6 and/or enterovirus A71 were also detected in 12 (85.7%) of 14 cases, with higher herpesvirus detection in cases versus controls (P < 0.001). Our findings suggest that the severity of the disease is related to co-infections involving AAV2 and one or more helper viruses.

Adeno-associated virus 2 infection in children with non-A-E hepatitis.

An outbreak of acute hepatitis of unknown aetiology in children was reported in Scotland1 in April 2022 and has now been identified in 35 countries2. Several recent studies have suggested an association with human adenovirus with this outbreak, a virus not commonly associated with hepatitis. Here we report a detailed case-control investigation and find an association between adeno-associated virus 2 (AAV2) infection and host genetics in disease susceptibility. Using next-generation sequencing, PCR with reverse transcription, serology and in situ hybridization, we detected recent infection with AAV2 in plasma and liver samples in 26 out of 32 (81%) cases of hepatitis compared with 5 out of 74 (7%) of samples from unaffected individuals. Furthermore, AAV2 was detected within ballooned hepatocytes alongside a prominent T cell infiltrate in liver biopsy samples. In keeping with a CD4+ T-cell-mediated immune pathology, the human leukocyte antigen (HLA) class II HLA-DRB1*04:01 allele was identified in 25 out of 27 cases (93%) compared with a background frequency of 10 out of 64 (16%; P = 5.49 × 10-12). In summary, we report an outbreak of acute paediatric hepatitis associated with AAV2 infection (most likely acquired as a co-infection with human adenovirus that is usually required as a 'helper virus' to support AAV2 replication) and disease susceptibility related to HLA class II status.

Clinical characteristics of hepatitis-associated aplastic anemia in children.

To understand the current situation of hepatitis-related aplastic anemia (HAAA) in children, we analyzed the patients with HAAA admitted to our hospital in the past 5 years to understand the disease characteristics and prognosis. The clinical data of patients with HAAA admitted to our hospital from February 2017 to May 2022 were retrospectively analyzed. A total of 81 patients with HAAA, 56 males and 25 females. The median onset age was 5.9 years. The median time from hepatitis to occurrence of hemocytopenia was 30 days, and the median follow-up time was 2.77 years. There were 23 cases (28.5%) of severe aplastic anemia (SAA), 50 cases of very severe aplastic anemia (VSAA), and 8 cases of non-severe aplastic anemia (NSAA). At the beginning of the disease, cytotoxic T lymphocyte (CTL) was higher than normal in 60% of patients, and the median CD4/CD8 ratio was 0.2. As of follow-up, 72 children survived, 4 were lost, and 5 died. Thirty-four cases were treated with immunosuppressive therapy (IST), with a median follow-up time of 0.97 years. The total reaction rate was 73.5% (25/34), the complete reaction rate was 67.6% (23/34), and the nonreaction rate was 26.5% (9/34). Multivariate analysis suggested that co-infection was an independent risk factor affecting the efficacy of IST at 6 months, with an OR value of 16.76, 95% CI (1.23, 227.95), P=0.034. No independent influencing factors were found at the end of follow-up. The proportion of CTL cells in peripheral blood of children with HAAA is relatively increased, and IST is effective in 73.5% of children. Co-infection may prolongs the time to response to IST.

Characterization and Investigation of Risk Factors for Late-Relapsing Hepatitis After Yellow Fever.

BACKGROUND: Late-relapsing hepatitis after yellow fever (LHep-YF) during the convalescent phase of the disease has been described during recent yellow fever (YF) outbreaks in Brazil. LHep-YF is marked by a rebound in liver enzymes and nonspecific clinical manifestations around 46-60 days after YF symptom onset. METHODS: Here we have characterized the clinical course and risk factors for LHep-YF using data from a representative cohort of patients who survived YF in Brazil, 2017-2018. A total of 221 YF-positive patients were discharged from the infectious disease reference hospital in Minas Gerais and were followed up at 30, 45, and 60 days post-symptom onset. RESULTS: From 46 to 60 days post-symptom onset, 16% of YF patients (n = 36/221) exhibited a rebound of aminotransferases (aspartate aminotransferase or alanine aminotransferase >500 IU/L), alkaline phosphatase, and total bilirubin levels. Other etiologies of liver inflammation such as infectious hepatitis, autoimmune hepatitis, and metabolic liver disease were ruled out. Jaundice, fatigue, headache, and low platelet levels were associated with LHep-YF. Demographic factors, clinical manifestations, laboratory tests, ultrasound findings, and viral load during the acute phase of YF were not associated with the occurrence of LHep-YF. CONCLUSIONS: These findings provide new data on the clinical course of Late-relapsing hepatitis during the convalescent phase of YF and highlight the need for extended patient follow-up after acute YF.

National Surveillance of Pediatric Acute Hepatitis of Unknown Etiology, Japan, October 2021-December 2022.

Pediatric acute hepatitis of unknown etiology has been reported globally since April 2022. In Japan, 139 possible cases with onset dates after October 2021 were reported as of December 2022. Three patients required liver transplants, but none died. Rates of adenovirus positivity (11/125, 9%) were lower than those for other countries.

Adeno-Associated Virus 2 and Human Adenovirus F41 in Wastewater during Outbreak of Severe Acute Hepatitis in Children, Ireland.

During April-July 2022, outbreaks of severe acute hepatitis of unknown etiology (SAHUE) were reported in 35 countries. Five percent of cases required liver transplantation, and 22 patients died. Viral metagenomic studies of clinical samples from SAHUE cases showed a correlation with human adenovirus F type 41 (HAdV-F41) and adeno-associated virus type 2 (AAV2). To explore the association between those DNA viruses and SAHUE in children in Ireland, we quantified HAdV-F41 and AAV2 in samples collected from a wastewater treatment plant serving 40% of Ireland's population. We noted a high correlation between HAdV-F41 and AAV2 circulation in the community and SAHUE clinical cases. Next-generation sequencing of the adenovirus hexon in wastewater demonstrated HAdV-F41 was the predominant HAdV type circulating. Our environmental analysis showed increased HAdV-F41 and AAV2 prevalence in the community during the SAHUE outbreak. Our findings highlight how wastewater sampling could aid in surveillance for respiratory adenovirus species.

Acute severe non-A-E-hepatitis of unknown origin in children - A 30-year retrospective observational study from north-west Germany.

BACKGROUND & AIMS: The etiology of the current acute severe non-A-E hepatitis epidemic in children remains unclear. We aimed to describe the occurrence and outcomes of acute severe hepatitis in pediatric patients in North-West Germany over a period of more than 30 years and in the context of the current epidemic. METHODS: We analyzed all cases of acute severe hepatitis in childhood, as defined by the World Health Organization, at Hannover Medical School from 1990 and at the University Hospital of Essen from 2009 to 16 May 2022. We separated cases into a historic cohort (1990-2018) and a COVID-19 era cohort (2019-2022). RESULTS: After application of exclusion criteria, 107 patients with acute severe hepatitis were identified (2.32 cases/center/year). Annual incidence per center rose significantly from 2.2 (historic cohort until 2018) to 4.25/center/year (from 2019, p = 0.002). Of all cases, 75.7% presented with jaundice, while 53.3% had clinical signs of infection. Two cases of adenovirus were proven (2004/2016), other pathogens detected were HHV-6 (4), CMV, HSV, EBV(3). Sixty-nine patients (64.5%) met the criteria of pediatric acute liver failure, with 44 requiring liver transplantation. In the current cohort, patients with infection, gastrointestinal symptoms and higher alanine aminotransferase had a better chance of transplant-free survival, whereas hepatic encephalopathy, higher international normalized ratio and bilirubin predicted a poor outcome. Twenty-five patients developed hepatitis-associated aplastic anemia and 19 patients (17.8%) died. CONCLUSIONS: Acute non-A-E-hepatitis in children is a rare but severe entity, often leading to acute liver failure. Clinical presentation in our current cohort resembles 2022 NAEH cases, with improved outcomes compared to historic controls. The rising incidence of NAEH in our centers since 2019, in the absence of adenoviral infection, indicates other potential triggers of similar NAEH cases. IMPACT AND IMPLICATIONS: As the current epidemic of severe acute non-A-E-hepatitis cases in children highlights our limited understanding in the field, we aim to describe current cases, characterizing the presentation over time, and defining similarities and discrepancies before and during the COVID-19 pandemic. Our data show a rising incidence of non-A-E-hepatitis cases since the beginning of the COVID-19 pandemic. These cases were not associated with adenoviral infections, suggesting that the recently described accumulation of adenovirus infections in relationship to hepatitis is a new trigger for a known phenomenon, rather than a new disease entity. Therefore, the role of protective isolation and subsequent lack of contact with trivial infections in children during the pandemic should be the subject of further examinations. We expect our data to contribute to a better understanding of severe acute hepatitis in childhood, increased vigilance for this potentially lethal disease beyond the current epidemic, and ultimately improved clinical diagnosis and care.

Molecular phylodynamics of fowl adenovirus serotype 11 and 8b from inclusion body hepatitis outbreaks.

Fowl adenovirus (FAdV) serotypes are involved in a variety of clinical manifestations in poultry and has resulted in substantial economic loss to the poultry farmers. Despite the endemicity of Inclusion body hepatitis (IBH) in South Asian countries, including India, its etiology is not well studied. In western India, the rural poultry flocks obtained from the vaccinated parents were experiencing disease outbreaks with substantial economic losses due to heavy outbreaks and mortality. Therefore, the study was conducted to decipher the molecular epidemiology of the FAdV from field outbreaks in western India. A total of 37 commercial broiler poultry flocks and 29 village poultry flocks of western India were visited during 2019 to 2021. Out of these, 19.14% flocks showed incidence of IBH during the age of 15 to 35 days. The mortality ranged from 3.3 percent to 55.28 percent. The samples were subjected for amplification of partial hexon gene covering loop 1 and loop 2. The results revealed 48.28% positivity by PCR. The sequence analysis identified 14 isolates as species D serotype 11 with 0.97 to 0.99% divergence and two as species E serotype 8b with 0.99% divergence. The FAdV-11 isolates showed amino acid substitutions D195N, T399A, N417S, and N496H. The amino acids I188 and N195 were conserved in FAdV-11. The molecular clock in Bayesian methods was used to determine most common ancestor. The isolates MH379249 and MH379248 were determined the most recent common ancestor for FAdV-11 and FAdV-8b isolates. The analysis suggested evolution of 10 FAdV-11 strains in 2012, and four FAdV-11 strains and two FAdV-8b strains in 2018.

Knowledge Dissemination for elimination Role of Academic Institutions in Eliminating Viral Hepatitis.

INTRODUCTION: India is looking to achieve hepatitis elimination status by 2030 through vaccination, diagnostic tests, medicines, and education campaigns. Awareness generation is essential to orient people regarding hepatitis B and C. The present study was done to assess the knowledge regarding hepatitis among students and staff of academic institutions and raise awareness through a series of webinars. MATERIALS AND METHODS: A cross-sectional study was conducted in 12 academic institutes from across the country between February and March 2022. The study included the dissemination of knowledge in the form of a webinar and the administration of a pre and postwebinar survey to assess the difference in the knowledge levels. RESULTS: A total of 914 individuals participated in the sessions. The mean baseline score for general epidemiology (max = 13 points), treatment and complications (max = 7 points), and prevention (max = 5 points) were 10.9 ± 2.1, 4.6 ± 1.3, and 3.2 ± 1.3, respectively. Overall, the mean score increased from 18.5 ± 3.6 to 20.4 ± 3.4 postwebinar, with an increase of +7.3%. CONCLUSION: The study observed significant improvement in knowledge among the participants following a low-cost 1-day training in webinar mode. Such training programs can be upscaled and help in educating the general public on hepatitis.

Incidence of hepatotoxicity associated with addition of immune checkpoint blockade to systemic solid tumor therapy: a meta-analysis of phase 3 randomized controlled trials.

Hepatotoxicity is a major immune-related adverse event that may become life-threatening. The impact of adding immune checkpoint blockade (ICB) to systemic therapy on the incidence of hepatotoxicity remains unknown. We performed a systematic review and meta-analysis to compare the incidence of hepatotoxicity among patients with cancer who received therapy with and without addition of ICB. PubMed, Embase, Web of Science, and Cochrane Library were searched to select phase 3 randomized controlled trials (RCTs) evaluating the effect of adding ICB to systemic therapy, placebo, or supportive care. The odds ratio (OR) of any grade and grade 3-5 hepatitis, elevations in aspartate aminotransferase (AST), and alanine aminotransferase (ALT) was pooled for meta-analysis. 43 RCTs with 28,905 participants were analyzed. Addition of ICB increased the incidence of hepatitis (any grade: OR, 2.13, 95% confidence interval [CI] 1.52-2.97, grade 3-5: OR, 2.66, 95% CI 1.72-4.11), elevated AST (any grade: OR, 2.16, 95% CI 1.73-2.70, grade 3-5: OR, 2.72, 95% CI 1.86-3.99), and elevated ALT (any grade: OR, 2.01, 95% CI 1.59-2.54, grade 3-5: OR, 2.40, 95% CI 1.62-3.55). Subgroup analysis based on the ICB mechanism revealed no significant heterogeneity among each mechanism for hepatitis (any Grade: I2 = 11.1%, p for heterogeneity = 0.32, grade 3-5: I2 = 0%, p = 0.48). Adding ICB to systemic therapy increases the incidence of hepatotoxicity regardless of the mechanism of ICB. Hepatotoxicity is common and vigilant monitoring of liver function is required during ICB therapy for patients with cancer.

Acute unexplained hepatitis in children.

Investigation of an outbreak of acute hepatitis of unknown cause in children may prompt research into other unexplained cases. Vijay Shankar Balakrishnan reports.

Interim Analysis of Acute Hepatitis of Unknown Etiology in Children Aged <10 Years - United States, October 2021-June 2022.

On April 21, 2022, CDC issued a health advisory† encouraging U.S. clinicians to report all patients aged <10 years with hepatitis of unknown etiology to public health authorities, after identification of similar cases in both the United States (1) and Europe.§ A high proportion of initially reported patients had adenovirus detected in whole blood specimens, thus the health advisory encouraged clinicians to consider requesting adenovirus testing, preferentially on whole blood specimens. For patients meeting the criteria in the health advisory (patients under investigation [PUIs]), jurisdictional public health authorities abstracted medical charts and interviewed patient caregivers. As of June 15, 2022, a total of 296 PUIs with hepatitis onset on or after October 1, 2021, were reported from 42 U.S. jurisdictions. The median age of PUIs was 2 years, 2 months. Most PUIs were hospitalized (89.9%); 18 (6.1%) required a liver transplant, and 11 (3.7%) died. Adenovirus was detected in a respiratory, blood, or stool specimen of 100 (44.6%) of 224 patients.¶ Current or past infection with SARS-CoV-2 (the virus that causes COVID-19) was reported in 10 of 98 (10.2%) and 32 of 123 (26.0%) patients, respectively. No common exposures (e.g., travel, food, or toxicants) were identified. This nationwide investigation is ongoing. Further clinical data are needed to understand the cause of hepatitis in these patients and to assess the potential association with adenovirus.

Prevalence, clinical characteristics and outcomes of hypoxic hepatitis in critically ill patients.

BACKGROUND: Hypoxic hepatitis (HH) is an important clinical entity in patients in the intensive care unit (ICU). The aims of the study were to assess the etiology, clinical characteristics and outcomes of HH in the ICU of a tertiary hospital. Secondary aim was to analyze the effects of concomitant ischemia in other organs than the liver. METHODS: All patients with HH, 2011-2018, in a university hospital ICU were included. Data were collected on etiology, relevant clinical data and outcome. HH was defined by an increase in aminotransferases ≥10 times the upper limit of normal within 48 h from a clinical event of cardiac, circulatory or respiratory failure. Other causes of liver cell necrosis were excluded. RESULTS: Of 9,931 patients hospitalized in the ICU, 159 (1.6%) fulfilled criteria for HH. In-hospital mortality occurred in 85 (53%) and 60 (38%) survived one year. Median ICU stay was five days (interquartile range (IQR) 3-10) and median hospital stay 16 days (IQR 7-32). Shock (48%), cardiac arrest (25%) and hypoxia (13%) were the most common causes of HH. Acute kidney injury (81%), rhabdomyolysis (50%), intestinal ischemia (6%) and ischemic pancreatitis (3%) occurred concomitantly. Age (odds ratio (OR) 1.05 (95% CI 1.02-1.09)), serum lactate (OR 2.61 (95% CI 1.23-5.50)) and lactate dehydrogenase (OR 1.14 (95% CI 1.02-1.27)) were predictors of mortality. CONCLUSIONS: Hypoxic hepatitis was related to shock in approximately 50% of cases and associated with high in-hospital mortality. HH was commonly associated with ischemia in other organs. In-hospital mortality was associated with age, lactate and LD.

[Consideration on the possible etiological mechanisms and countermeasures about severe acute hepatitis of unknown origin in children].

Since April 2022, severe acute hepatitis of unknown origin in children has spread to 35 countries and regions around the world, and more than 1 010 cases have been reported. Since the severe acute hepatitis of unknown origin involves a wide range of areas and has a high rate, it is critical to identify the etiology and establish effective preventive, diagnostic and therapeutic measures as soon as possible. This study discusses the possible mechanisms and countermeasures of the severe acute hepatitis of unknown origin in children. It speculates that the occurrence of the recent severe acute hepatitis might be related to adenovirus, adeno-associated virus infection, and the COVID-19 epidemic, while the difference in HLA polymorphism among different races might be related to the fact that reported cases were more common in Europe and the United States. Based on the currently available evidence, it can be preliminarily judged that the risk of large-scale outbreak of severe acute hepatitis of unknown origin in children would be low in China, but the persistent awareness and vigilance of the etiology is still needed.

[Consideration on the emerging acute severe hepatitis cases with unknown etiology in children of some countries].

Since January 2022, acute severe hepatitis cases with unknown etiology in children have occurred in many countries in Europe and the United States, and 43.8% of the cases were positive for human adenovirus (HAdV), and some cases were identified as HAdV-41. However, more evidences including etiology, genomics, liver pathology, and immunohistochemistry are needed to determine the main cause of this outbreak. At present, due to the lack of systematic surveillance and research on hepatitis caused by HAdV infection, it is impossible to determine whether there are similar hepatitis cases occurred in China. It is urgent to carry out HAdV virolgocial surveillance based on clinical symptom, and potential risk of acute severe hepatitis should be studied as soon as possible according to the available relevant clinical, epidemiological and virological data, as well as risk factor information, which will provide scientific and technical support for the prevention and control of HAdV-related diseases.

[An overview of the global epidemic of severe acute hepatitis of unknown etiology in children].

In April 2022, the United Kingdom was the first to report 74 cases of severe acute hepatitis in children monitored across different parts of the country. Hepatitis A to E viruses were not the common infectious etiological agents. As a result, the World Health Organization is closely monitoring reports of its unknown etiology and high severity incidence, and has warned that more cases are likely to come. As of May 1, 2022, 20 countries in the world have reported 228 cases. This paper briefly introduces the general situation of this outbreak.

Metabolic Inflammation-A Role for Hepatic Inflammatory Pathways as Drivers of Comorbidities in Nonalcoholic Fatty Liver Disease?

Nonalcoholic fatty liver disease (NAFLD) is a global and growing health concern. Emerging evidence points toward metabolic inflammation as a key process in the fatty liver that contributes to multiorgan morbidity. Key extrahepatic comorbidities that are influenced by NAFLD are type 2 diabetes, cardiovascular disease, and impaired neurocognitive function. Importantly, the presence of nonalcoholic steatohepatitis and advanced hepatic fibrosis increase the risk for systemic comorbidity in NAFLD. Although the precise nature of the crosstalk between the liver and other organs has not yet been fully elucidated, there is emerging evidence that metabolic inflammation-in part, emanating from the fatty liver-is the engine that drives cellular dysfunction, cell death, and deleterious remodeling within various body tissues. This review describes several inflammatory pathways and mediators that have been implicated as links between NAFLD and type 2 diabetes, cardiovascular disease, and neurocognitive decline.

Acute Hepatitis Is a Prominent Presentation of the Multisystem Inflammatory Syndrome in Children: A Single-Center Report.

BACKGROUND AND AIMS: A newly recognized multisystem inflammatory syndrome in children (MIS-C) has had a paradigm-shifting effect on the perception of severe acute respiratory syndrome, coronavirus-2 (SARS-CoV-2) illness severity in children. We report the clinical and biochemical features of liver involvement, and the comorbidities that present with hepatitis, in a substantial cohort of patients. APPROACH AND RESULTS: This is a retrospective cohort study of 44 patients with MIS-C admitted at Morgan Stanley Children's Hospital of New York-Presbyterian during April and May 2020. We evaluated the number of patients who developed hepatitis and examined both demographics and inflammatory laboratory values to ascertain those that were at higher risk for liver involvement and more severe disease. Hepatitis was present in 19 subjects (43%) and was associated with more severe disease. Persons with hepatitis had significantly higher rates of shock at presentation (21.1% vs. 0%; P = 0.008), greater respiratory support requirement (42.1% vs. 12%; P = 0.005), and longer hospitalization times (median, 7 [interquartile range {IQR}, 5, 10] vs. 4 days [IQR, 3.5, 6.5]; P < 0.05). Patients with hepatitis also had significantly higher levels of ferritin (706.9 vs. 334.2 mg/mL; P < 0.01), interleukin-6 (233.9 vs. 174.7 pg/mL; P < 0.05), troponin (83.0 vs. 28.5 ng/L; P < 0.05), and B-type natriuretic peptide (7,424.5 vs. 3,209.5 pg/mL; P < 0.05). The single patient with liver failure also developed multiorgan failure requiring vasopressors, hemodialysis, and mechanical ventilation. All patients were discharged, though >50% had persistent hepatitis up to 1 month after discharge. CONCLUSIONS: Hepatitis is common in children with MIS-C and is associated with a more severe presentation and persistent elevation of liver function tests in many. Despite the positive outcomes reported here, close follow-up is warranted given the limited knowledge of the long-term impact of SARS-CoV-2 on the liver.