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.

A Case Series of Children with Acute Hepatitis and Human Adenovirus Infection.

BACKGROUND: Human adenoviruses typically cause self-limited respiratory, gastrointestinal, and conjunctival infections in healthy children. In late 2021 and early 2022, several previously healthy children were identified with acute hepatitis and human adenovirus viremia. METHODS: We used International Classification of Diseases, 10th Revision, codes to identify all children (<18 years of age) with hepatitis who were admitted to Children's of Alabama hospital between October 1, 2021, and February 28, 2022; those with acute hepatitis who also tested positive for human adenovirus by whole-blood quantitative polymerase chain reaction (PCR) were included in our case series. Demographic, clinical, laboratory, and treatment data were obtained from medical records. Residual blood specimens were sent for diagnostic confirmation and human adenovirus typing. RESULTS: A total of 15 children were identified with acute hepatitis - 6 (40%) who had hepatitis with an identified cause and 9 (60%) who had hepatitis without a known cause. Eight (89%) of the patients with hepatitis of unknown cause tested positive for human adenovirus. These 8 patients plus 1 additional patient referred to this facility for follow-up were included in this case series (median age, 2 years 11 months; age range, 1 year 1 month to 6 years 5 months). Liver biopsies indicated mild-to-moderate active hepatitis in 6 children, some with and some without cholestasis, but did not show evidence of human adenovirus on immunohistochemical examination or electron microscopy. PCR testing of liver tissue for human adenovirus was positive in 3 children (50%). Sequencing of specimens from 5 children showed three distinct human adenovirus type 41 hexon variants. Two children underwent liver transplantation; all the others recovered with supportive care. CONCLUSIONS: Human adenovirus viremia was present in the majority of children with acute hepatitis of unknown cause admitted to Children's of Alabama from October 1, 2021, to February 28, 2022, but whether human adenovirus was causative remains unclear. Sequencing results suggest that if human adenovirus was causative, this was not an outbreak driven by a single strain. (Funded in part by the Centers for Disease Control and Prevention.).

Beyond Varices: Complications of Cirrhotic Portal Hypertension in Pediatrics.

Complications of cirrhotic portal hypertension (PHTN) in children are broad and include clinical manifestations ranging from variceal hemorrhage, hepatic encephalopathy (HE), ascites, spontaneous bacterial peritonitis (SBP), and hepatorenal syndrome (HRS) to less common conditions such as hepatopulmonary syndrome, portopulmonary hypertension, and cirrhotic cardiomyopathy. The approaches to the diagnosis and management of these complications have become standard of practice in adults with cirrhosis with many guidance statements available. However, there is limited literature on the diagnosis and management of these complications of PHTN in children with much of the current guidance available focused on variceal hemorrhage. The aim of this review is to summarize the current literature in adults who experience these complications of cirrhotic PHTN beyond variceal hemorrhage and present the available literature in children, with a focus on diagnosis, management, and liver transplant decision making in children with cirrhosis who develop ascites, SBP, HRS, HE, and cardiopulmonary complications.

Acute liver failure and unique challenges of pediatric liver transplantation amidst a worldwide cluster of adenovirus-associated hepatitis.

Investigation into a recent cluster of acute hepatitis in children from the southeastern United States identified human adenovirus (HAdV) DNAemia in all 9 cases. Molecular genotyping in 5 of 9 (56%) children identified HAdV type 41 in all cases (100%). Importantly, 2 children from this cluster progressed rapidly to pediatric acute liver failure (PALF) and required liver transplantation. HAdV type 41, a known cause of self-limited gastroenteritis, has not previously been associated with severe cholestatic hepatitis and liver failure in healthy children. Adenovirus polymerase chain reaction assay and sequencing of amplicons performed on DNA extracted from formalin-fixed, paraffin-embedded liver tissue also identified adenovirus species F (HAdV type 40 or 41) in these 2 children with PALF. Transplant considerations and successful liver transplantation in such situations remain scarce. In this report, we describe the clinical course, laboratory results, liver pathology, and treatment of 2 children with PALF associated with HAdV type 41, one of whom developed secondary hemophagocytic lymphohistiocytosis. Their successful posttransplant outcomes demonstrate the importance of early multidisciplinary medical management and the feasibility of liver transplantation in some children with PALF and HAdV DNAemia.

Acute Hepatitis and Adenovirus Infection Among Children - Alabama, October 2021-February 2022.

During October-November 2021, clinicians at a children's hospital in Alabama identified five pediatric patients with severe hepatitis and adenovirus viremia upon admission. In November 2021, hospital clinicians, the Alabama Department of Public Health, the Jefferson County Department of Health, and CDC began an investigation. This activity was reviewed by CDC and conducted consistent with applicable federal law and CDC policy.

Operational Definitions for Chronic Liver Disease Manifestations and Recurring Clinical Events in Biliary Atresia.

BACKGROUND: The disease course of biliary atresia (BA) may be complicated by development of chronic liver disease (CLD) manifestations (eg, ascites) and recurring clinical events (eg, cholangitis). Most pediatric CLD-manifestations/events lack standardized operational definitions, leading to inconsistent identification in clinical research. This study aimed to develop operational research definitions of CLD-manifestations/events in BA for application in retrospective analysis. METHODS: Operational definitions of CLD-manifestations/events were developed by literature review and revised by a panel of experienced pediatric hepatologists. Definitions were applied to a single-center review of infants with BA post-Kasai. Manifestations/events were captured until last clinical visit with native liver (SNL), liver transplantation (LT), or death. Native liver survival and event-free survival were estimated by Kaplan-Meier method. Cluster analysis was performed to identify similar patterns of manifestation/event development. RESULTS: Of 65 infants with BA post-Kasai (2006-18; median Kasai 56.8 days; 65% girls), 29 underwent LT (median 12.9 months) and 4 died without LT (median 6.9 months). Seventy-six percent of CLD-manifestations/events presented within the first year. Presence of definite clinically evident portal hypertension, thrombocytopenia, and dCE ascites were associated with poor transplant-free survival (P < 0.01). Similar pattern developments of CLD-manifestations/events identified 3 outcome groups: poor outcomes (87.8% LT/death), SNL with manifestations/events, and SNL with few/no events. CONCLUSIONS: Operational definitions can provide a timely description of the disease course progression in infants with BA. Research definitions may provide better consistency in future pediatric CLD studies. Furthermore, definitions may serve as endpoints in therapeutic trials or used as variables for disease pattern identification in potential multicenter studies.

Unique Inflammatory Bowel Disease Phenotype of Pediatric Primary Sclerosing Cholangitis: A Single-Center Study.

OBJECTIVES: In adults, primary sclerosing cholangitis (PSC), a cholestatic liver disease characterized by inflammation/fibrosis of intra/extrahepatic bile ducts, associates with a milder form of inflammatory bowel disease (IBD), particularly ulcerative colitis (UC). The pediatric PSC-IBD phenotype is less well characterized. METHODS: We performed a retrospective, single-center study examining patients with PSC-IBD at Texas Children's Hospital between 2000 and 2015. IBD-phenotype (Modified Montreal Classification), medications, laboratory values, endoscopic records, and IBD-based hospital admissions were collected. PSC-UC phenotype was compared to UC, non-PSC patients (n = 95) from Texas Children's Hospital. Elevated gamma-glutamyl transpeptidase levels were compared to calprotectin levels and IBD-flare activity, that is, gastrointestinal symptoms resulting in office/emergency department visits or hospital admission. RESULTS: Of 39 patients with PSC-IBD, 34 (87.2%) had UC (PSC-UC) and 5 (12.8%) had Crohn disease. Pancolitis was more common in PSC-UC than UC, non-PSC (96.3%, 64%, P = 0.0009). Patients with PSC-UC required less treatment with steroids (76.5%, 91.6%, P = 0.0326) or infliximab (8.8%, 37.9%, P = 0.0011), and fewer had at least 1 IBD-related hospital admission (32.4%, 63.2%, P = 0.0025) than UC, non-PSC. Progression to colectomy was significantly less (5.8%, 24.2%, P = 0.0223) in PSC-UC. Median diagnosis-to-colectomy time tended to be longer in PSC-UC (6.37, 2.5 years, P = 0.0792). In 2 smaller subsets, gamma-glutamyl transpeptidase did not correlate with calprotectin in PSC-UC (n = 11, P = 0.7922) and less strongly associated with IBD-flares in PSC-UC than UC, non-PSC (n = 33, n = 67; 15.2%, 41.8%, P = 0.0120). CONCLUSIONS: Pediatric PSC appears to associate with milder pancolitic-UC. PSC and IBD activity do not appear to correlate. Our findings may provide useful information toward etiology and management of pediatric PSC-IBD.

Characteristics of infections and their risk factors in children with biliary atresia.

BACKGROUND: Children with biliary atresia (BA) may experience various infections (e.g., cholangitis, bacteremia, and viral respiratory infections (VRI)) throughout their disease course. This study aimed to identify and describe these infections and their risk factors for development in children with BA. METHODS: This retrospective observational study identified infections in children with BA using predefined criteria, including VRI, bacteremia with and without central line (CL), bacterial peritonitis, positive stool pathogens, urinary tract infections, and cholangitis. Infections were identified until liver transplant, death or last follow-up with native liver. Infection-free survival was estimated by Kaplan-Meier analysis. Logistic regression was used to estimate odds of infection per clinical characteristics. Cluster analysis was performed to identify patterns of infection development. RESULTS: 48 of 65 (73.8%) children had ≥1 infection during their disease course (mean length of follow up: 40.2 months). Cholangitis (n = 30) and VRI (n = 21) were most common. Nearly half (45%) of all infections developed within 3-months of Kasai hepatoportoenterostomy. Kasai performed ≥45 days of life was associated with 3.5-fold increased risk of any infection (95% CI 1.2-11.4). Risk of VRI was inversely related to platelet count at 1-month post-Kasai (OR 0.5, 0.19-0.99). Cluster analysis of infectious patterns identified three unique cohorts of patients based on their infection history: no/few infections (n = 18), mostly cholangitis (n = 20) or mixed infections (n = 27). CONCLUSION: Variability of infection risk exists amongst children with BA. Age at Kasai and platelet count are risk factors for future infections, suggesting that patients with more severe disease are at greater risk. Cirrhosis associated immune deficiency may exist in chronic pediatric liver disease and should be the subject of future investigations in order to optimize outcomes.

Clinicopathologic Features of Severe Acute Hepatitis Associated With Adenovirus Infection in Children.

A recent increase in reports of severe acute hepatitis of unknown etiology in children is under investigation. Although adenovirus has been frequently detected, its role remains unclear, and systematic histopathologic analysis is lacking. We conducted a retrospective study of 11 children hospitalized between October 2021 and May 2022 with unexplained acute hepatitis and concurrent adenovirus infection. Liver biopsies collected shortly after admission demonstrated moderately to severely active hepatitis in 8/11 (73%) cases, characterized by marked portal mixed inflammation, moderate-to-severe interface activity, and milder lobular inflammation. Clusters of plasma cells were present in 6/11 (55%) cases, mimicking autoimmune hepatitis. Semiquantitative scoring of 17 discrete histologic features found that greater degrees of portal inflammation, interface activity, bile duct injury, bile ductular reaction, lobular inflammation, Kupffer cell activation, and hepatocyte focal necrosis were significantly more common in these cases in comparison to the control group of unexplained acute severe hepatitis without adenovirus infection. Liver biopsy immunohistochemistry was negative for adenovirus in all cases. Polymerase chain reaction testing of liver tissue was positive for the enteric adenovirus serotypes 41 (species F) in 10/11 (91%) cases. An immunoprofile study of hepatic infiltrating lymphocytes in 1 patient revealed the presence of large numbers of CD3 + and CD4 + lymphocytes. Nine patients received supportive treatment without steroids and recovered without the need for liver transplantation. In summary, liver injury in children with severe acute hepatitis and adenovirus infection is characterized by a hepatitic pattern that resembles severe autoimmune hepatitis and may represent an immune-mediated process associated with viral infection.

Pediatric Acute Liver Failure Secondary to Autoimmune Hepatitis in an Infant With Thrombocytopenia-Absent Radius (TAR) Syndrome: A Case Report.

Thrombocytopenia absent radius (TAR) syndrome is a rare genetic disorder that has been associated with food protein-induced allergic proctocolitis and transient leukemoid reactions, among other manifestations. There has been no prior reports of its association with autoimmune disease, more specifically, autoimmune hepatitis (AIH) or the development of pediatric acute liver failure (PALF). We present a case of an 8-month-old infant with TAR syndrome who presented with PALF, secondary to AIH with elevated liver-kidney microsomal antibody (>1:2560). She received a liver transplant and had a very complicated postoperative course including severe T-cell-mediated rejection, infection, biliary stricture, persistently elevated liver-kidney microsomal antibodies, and antibody-mediated rejection. Ultimately, these complications led to graft failure, severe sepsis, and death. This case highlights a new association of TAR syndrome with AIH and PALF and a potentially aggressive nature of AIH both pre- and post-transplant.

Biopsy Validated Study of Biomarkers for Liver Fibrosis and Transplant Prediction in Inherited Cholestasis.

Alagille syndrome (ALGS) and progressive familial intrahepatic cholestasis (PFIC) are inherited cholestatic disorders with risk of developing end-stage liver disease requiring liver transplantation (LT). We investigated aspartate aminotransferase-to-platelet ratio index (APRI), Fibrosis-4 score (FIB-4), and conjugated bilirubin as biomarkers to assess fibrosis severity and risk for LT among children with ALGS and PFIC. This multicenter, cross-sectional study included 64 children with ALGS or PFIC (per genetics or strict clinical criteria) with APRI, FIB-4, and conjugated bilirubin levels collected within ±90 days of their most recent liver biopsy. A single, blinded pathologist staged all biopsies (metavir; F0-F2: nonsevere, F3-F4: severe). Logistic regression and area under the receiver operating characteristic curve analysis (AUC) were used to assess biomarker associations with fibrosis severity and risk for LT. In ALGS, only APRI distinguished F3-F4 (AUC 0.72, P = 0.012), with a cutoff greater than 2.97 demonstrating a sensitivity of 61.5% (95% confidence interval 0.32, 0.86) and specificity of 81.5% (0.62, 0.94). In ALGS, a 50% increase of APRI increased the odds of F3-F4 by 1.31-fold (1.04, 1.65; P = 0.023). In ALGS, APRI (AUC 0.87; P < 0.001) and FIB-4 (AUC 0.84; P < 0.001) were able to predict risk for LT. In PFIC, only APRI distinguished F3-4 (AUC 0.74, P = 0.039), with a cutoff greater than 0.99 demonstrating a sensitivity of 80% (0.44, 0.98) and specificity of 64.3% (0.35, 0.87). In PFIC, only FIB-4 was able predict risk for LT (AUC 0.80; P = 0.002). In ALGS or PFIC, conjugated bilirubin could not distinguish F3-F4 or predict risk for LT. Conclusion: This liver biopsy-validated study suggests that APRI is able to distinguish F3-F4 from F0-F2 in ALGS and PFIC. APRI and FIB-4 may also serve as predictors of risk for LT in ALGS (APRI and FIB-4) and PFIC (FIB-4).