Relationship between genotypes and clinical manifestation, pathology, and cccDNA in Chinese children with hepatitis B virus-associated glomerulonephritis

Targeting hepatitis B virus-associated nephropathy: efficacy and challenges of current antiviral treatments

Hepatitis B virus (HBV) infection remains a major global health challenge, affecting approximately 296 million people and causing significant mortality annually. Despite vaccination efforts, HBV prevalence persists, particularly in low- and middle-income regions and endemic areas like China. HBV is closely associated with various kidney diseases, including acute kidney injury, chronic kidney disease, and glomerulonephritis, through mechanisms such as immune complex deposition, direct viral invasion, and chronic inflammation. Patients undergoing hemodialysis or kidney transplantation are at increased risk of HBV infection and reactivation, highlighting the need for effective preventive and therapeutic measures. This review examines the classification and clinical features of HBV-associated nephropathy, focusing on membranous nephropathy and membranoproliferative glomerulonephritis. It explores the pathogenesis, emphasizing immune complex deposition and podocyte apoptosis. Antiviral therapy, particularly with nucleos(t)ide analogs like entecavir and tenofovir (including TAF and TMF), demonstrates superior efficacy and safety compared to older agents such as lamivudine and adefovir. While interferon therapy offers benefits, its use is limited by adverse effects. Additionally, individualized treatment strategies for specific populations, including pregnant women and HIV co-infected patients, are crucial. Addressing HBV-associated nephropathy requires enhanced surveillance, timely antiviral intervention, and tailored therapeutic approaches to improve patient outcomes.

Liver Histology of Treatment-Naïve Children with Chronic Hepatitis B Virus Infection in Shanghai China

BACKGROUND & AIMS

Chronic hepatitis B (CHB) is associated with high morbidity and mortality. We aimed to investigate associations between hepatic histology and clinical characteristics in treatment-naïve children with CHB in Shanghai, China.

METHODS

The liver biopsy specimens of 278 treatment-naïve children with CHB virus infection were scored for inflammation and fibrosis, and correlations with clinical and laboratory data were determined.

RESULTS

CHB clinical, virologic and pathologic features were studied in 278 treatment-naïve children (177 males (63.7%)) from Shanghai, China. Maternal sera were hepatitis B surface antigen (HBsAg) positive for 277 children. At biopsy, 87.4% of patients were hepatitis B e antigen positive. The median age at biopsy was 5.1 years (interquartile range 2.8-8.4 years). Hepatitis B virus (HBV) DNA levels were generally high (mean 7.4 log₁₀ IU/ml), as were levels of serum alanine aminotransferase (ALT, median 105 U/L). Using the Metavir histology activity index scoring system, no, mild, moderate and severe inflammation was seen in 2.9%, 22.3%, 73.4%, and 1.4% of patients, respectively. No fibrosis, mild fibrosis, moderate fibrosis, and cirrhosis was seen in 11.5%, 32.7%, 47.5%, and 8.3% of patients, respectively. When the serum ALT level was ≤80 (2× the upper limit of normal) and >80 U/L, the inflammation score (P<0.0001) was significantly different. And the fibrosis score was significantly different (P<0.0001), either. Inflammation and fibrosis were aggravated with increasing ALT levels. Fibrosis scores were significantly higher in children aged ≤3 than aged >3 years (P<0.0001). The rates of moderate fibrosis and cirrhosis were higher in children aged ≤3 years at biopsy. No correlations were found between histologic changes and sex, HBV genotype or HBV DNA level.

CONCLUSION

Substantial heterogeneity in inflammatory and fibrotic levels was observed in treatment-naïve children with CHB in Shanghai, China. Serum ALT levels >80 U/L may be a strong indicator of the degree of hepatic inflammation and fibrosis severity. Moderate fibrosis and cirrhosis can appear in children aged <3 years or younger.

Treatment of hepatitis B virus infection in children and adolescents

Hepatitis B virus (HBV) infection is one of the main causes of morbidity and mortality worldwide. Most children acquire the infection perinatally or during early childhood and develop a chronic hepatitis characterized by a high viral replication and a low-inflammation phase of infection, with normal or only slightly raised aminotransferases. Although a conservative approach in children is usually recommended, different therapies exist and different therapeutic approaches are possible. The main goals of antiviral treatment for children with chronic HBV infection are to suppress viral replication and to warn the disease progression to cirrhosis and hepatocellular carcinoma, although these complications are rare in children. Both United States Food and Drug Administration (US-FDA) and European Medicines Agency (EMA) have approved interferon alfa-2b for children aged 1 year and older, pegylated interferon alfa-2a and lamivudine for children aged 3 years and older, entecavir for use in children aged 2 years and older, and adefovir for use in those 12 years of age and older. Tenofovir disoproxil fumarate is approved by EMA for children aged 2 years and older and by US-FDA for treatment in children aged 12 years and older. Finally, EMA has approved the use of tenofovir alafenamide for treatment of children aged 12 years and older or for children weighing more than 35 kg independent of age. This narrative review will provide the framework for summarizing indications to antiviral therapy in the management of chronic HBV infection in children and adolescents.

Hepatitis B virus X protein decreases nephrin expression and induces podocyte apoptosis via activating STAT3

The gene for hepatitis B virus X protein (HBx) comprises the smallest open reading frame in the HBV genome, and the protein product can activate various cell signaling pathways and regulate apoptosis, among other effects. However, in different cell types and under different external conditions, its mechanism of action differs. In the present study, the effect of HBx on the viability and apoptosis of mouse podocyte clone 5 (MPC5) cells was investigated. The cells were transfected with the HBx gene using pEX plasmid, and real-time quantitative PCR and western blot analysis were used to test the transfection efficiency and assess related protein expression. The highest expression of HBx occurred at 48 h after MPC5 cells were transfected with HBx. The expression of nephrin protein in the HBx transfection group was lower than that in blank and negative control groups. Following transfection of the HBx gene, podocyte viability was suppressed, while the rate of cell apoptosis was increased; moreover, the expression of signal transducer and activator of transcription 3 (STAT3) and phospho-STAT3 was increased compared with in the control groups. The present study suggests that STAT3 activation may be involved in the pathogenic mechanism of renal injuries caused by HBV injection. Thus STAT3 is a potential molecular target in the treatment of HBV-GN.

Hepatitis B virus infection in children and adolescents

Hepatitis B virus (HBV) infection is a major cause of acute and chronic liver disease and associated morbidity and mortality worldwide. Vertical (mother-to-child) and horizontal early childhood transmission are the main routes of HBV transmission and are responsible for most chronic infections, including among adults who bear the greatest burden of morbidity and mortality. Universal hepatitis B immunisation at birth and in infancy is the key strategy for global elimination of HBV infection, and has been highly effective in reducing new vertical infections. However, global progress in scale-up of HBV testing and treatment has been slow in adults and children. In this Series paper, we summarise knowledge on the epidemiology, natural history, and treatment of chronic HBV infection in adolescents and children, and we highlight key differences from HBV infection in adults. The estimated global prevalence of HBV infection in children aged 5 years or younger is 1·3%. Most children are in the high-replication, low-inflammation phase of infection, with normal or only slightly raised aminotransferases; cirrhosis and hepatocellular carcinoma are rare. Although entecavir is approved and recommended for children aged 2-17 years, and tenofovir for those aged 12-18 years, a conservative approach to treatment initiation in children is recommended. Key actions to address current policy gaps include: validation of non-invasive tests for liver disease staging; additional immunopathogenesis studies in children with HBV infection; long-term follow-up of children on nucleoside or nucleotide analogue regimens to inform guidance on when to start treatment; evaluation of different treatment strategies for children with high rates of HBV replication; and establishment of paediatric treatment registries and international consortia to promote collaborative research.