Acute severe hepatitis of unknown origin in children: considerations from the perspective of immunology

A Case of Reactivated Acute Hepatitis in a 12-month-old Infant With Multiviral Infection, Including SARS-CoV-2 and Adenovirus

Adenovirus hepatitis is of global concern due to its increasing incidence and poorly understood pathogenesis. Historically, adenovirus has contributed to the development of severe hepatitis in immunocompromised patients. The clinical course and management of such infections in previously healthy children remains elusive. We present a case of severe acute hepatitis in a previously healthy 12-month-old infant with a history of SARS-CoV-2 infection followed by multiviral infection including adenovirus. Additional evaluation revealed acute hepatitis without evidence of acute liver failure except for mild coagulopathy. She demonstrated clinical improvement with supportive therapy but later experienced reactivated hepatitis in the setting of a third new viral infection thereby warranting a second hospitalization. A liver biopsy was obtained due to concern for an underlying immunologic or metabolic etiology of her prolonged hepatitis. Our case provides insight into the medical management and clinical course of a previously healthy child with a history of SARS-CoV-2 and adenovirus infections leading to reactivated acute hepatitis.

May 2022 acute hepatitis outbreak, is there a role for COVID-19 and other viruses?

There has been an increasing number of reported cases of acute hepatitis of unknown origin in previously healthy children since first reported on March 31, 2022. This clinical syndrome is identified by jaundice and markedly elevated liver enzymes with increased aspartate transaminase and/or alanine aminotransaminase (greater than 500 IU/L). We conducted an inclusive literature review with respect to acute hepatitis outbreaks in children using the search terms acute hepatitis, outbreak, children, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), coronavirus disease 2019 (COVID-19), and adenovirus. According to the cumulative data presented in four main studies, the median age is 4 years, with a male predominance (1.3:1). Jaundice was the most common clinical manifestation (69%), followed by vomiting (63%), anorexia (52.9%), diarrhea (47.2%), abdominal pain (39%), pyrexia (33.3%), pale stool (30%), and dark urine (30%). Coryza and lethargy were reported in 16.6%, while pruritus was reported in 2% of cases. Acute liver failure was observed in 25% of cases. The exact mechanism of this acute hepatitis outbreak is still not entirely clear. Adenoviruses and SARS-CoV-2 were detected in a significant number of patients. Coinfection with adenovirus and SARS-CoV-2 could be a possible underlying mechanism. However, other possible infections and mechanisms must be considered in the pathogenesis of this condition. Acute hepatitis of unknown origin in children has been a serious problem since the start of the COVID-19 pandemic but has not yet been sufficiently addressed. Many questions remain regarding the underlying mechanisms leading to acute liver failure in children, and it is likely that extensive future research is needed.

Updated information regarding acute severe hepatitis of unknown origin in children: Viewpoints of and insights from pediatricians

Recently, the morbidity of acute severe hepatitis of unknown origin in children (SHIC) has tended to decrease, but this condition should not be ignored because of its uncertain but severe nature. The current study briefly summarizes updated information regarding the epidemiological, clinical, and etiological aspects of SHIC based on the newest information available. Opinions from pediatricians are also presented. In light of the status quo of SHIC and COVID-19 globally, several suggestions are proposed to improve future studies, which could help to further explore the underlying mechanisms of SHIC in the context of COVID-19.

Acute Hepatitis of Unknown Origin in Pediatric Age Group: Recent Outbreaks and Approach to Management

Acute hepatitis has always been a public health concern, but the recent clustering of cases in various parts of the world has drawn some special attention. The sudden rise in cases has mainly been among the pediatric population of around 35 countries around the world, including developed countries such as the United States, the United Kingdom, and European countries. The outbreaks have had a devastating impact, with around 10% of the affected patients developing liver failure. The clinical presentation of patients resembles any other case of acute hepatitis, with the major symptoms being: jaundice (68.8%), vomiting (57.6%), and gastrointestinal symptoms such as abdominal pain (36.1%) and nausea (25.7%). Interestingly, the cases have tested negative for hepatotropic viruses Hep A, B, C, and E, thus giving rise to the terms Hepatitis of Unknown Origin or non-HepA-E hepatitis. Many causes have been attributed to the disease, with major evidence seen for adenovirus and SARS-CoV-2. International agencies have stressed on establishing diagnostic and management protocols to limit these outbreaks. As the understanding has evolved over time, diagnostic and management faculties have found more shape. The current review was designed to comprehensively compile all existing data and whittle it down to evidence-based conclusions to help clinicians.

Acute hepatitis of unknown origin in children: A combination of factors

On 5 April 2022, the World Health Organization was notified of 10 cases of severe acute hepatitis of unknown etiology in children under 10 years of age in the United Kingdom. Although the exact cause of a proportion of pediatric acute hepatitis and acute liver failure cases was unclear, the above event has caused widespread concern worldwide. As of 14 September 2022, approximately 1,296 probable cases of acute hepatitis of unknown etiology have been reported from 37 countries/regions, of which approximately 55 required or received liver transplantation and 29 died. Although the etiology of acute hepatitis of unknown origin in children remains unclear, many hypotheses have been proposed about the disease. Instead of individual factors such as "adenovirus infection," "SARS-CoV-2 related," and "Adeno-associated virus 2 with helper virus coinfection," it is more likely due to a combination of factors. Accordingly, there is an urgent need for more data and research to clarify the disease etiology. This review aims to provide a historical perspective of acute hepatitis of unknown etiology in children in the past decades and summarize the current hypothesis and evidence on this emerging disease.