Editor’s Note: Viral hepatitis has imposed a significant disease burden globally. While China’s efforts in controlling viral hepatitis have shown initial success, the large number of chronic viral hepatitis patients makes prevention and control efforts still challenging. Hepatitis D, caused by hepatitis D virus (HDV) infection, is a liver disease that poses a higher risk of liver cirrhosis and hepatocellular carcinoma in individuals co-infected with HDV and hepatitis B virus (HBV) compared to those with HBV alone. During the 32nd Annual Meeting of the Asian Pacific Association for the Study of the Liver (APASL), Professor Duan Zhongping and Professor Zou Huaibin’s team from Beijing You’an Hospital, Capital Medical University, China, presented their findings on HDV infection in chronic HBV-infected patients at different disease stages.
Research Background:
HDV is a defective small RNA virus that requires the presence or assistance of hepatitis B virus (HBV) surface antigen envelope to infect liver cells. The distribution and prevalence of HDV in a region are closely related to the local prevalence and distribution of HBV. Currently, China has approximately 86 million HBV-infected individuals, making HBV infection one of the most prominent public health issues and a significant liver disease burden in the country. Individuals co-infected with HBV and HDV progress to severe liver disease at a faster rate than those with HBV alone. HBV/HDV co-infection significantly increases the risk of liver cirrhosis, hepatocellular carcinoma, end-stage liver disease, and liver-related mortality.
Historically, due to limited availability, sensitivity, and specificity of HDV testing kits, coupled with the misconception among many clinicians that HDV infection is rare, there has been insufficient attention given to HDV infection in China. However, with the improved availability and sensitivity of HDV testing kits and rapid developments in anti-HDV drug research, screening and diagnosis of HDV are now receiving greater attention. Clearly defining the current status of HDV co-infection among chronic HBV-infected individuals in China and its correlation with disease severity is becoming increasingly important.
Research Methods:
This prospective study included a total of 1,059 chronic HBV-infected patients at different disease stages or severity levels treated at Beijing You’an Hospital, Capital Medical University. Patients were categorized into five different disease stages based on their medical history, clinical presentations, liver function biochemical indicators, hepatitis B virus (HBV) serological markers, HBV DNA levels, abdominal ultrasound or imaging results, and liver tissue pathology results (in some patients). The five disease stages were as follows: HBV carriers (n=241), chronic hepatitis B patients (n=263), liver cirrhosis patients (n=216), hepatocellular carcinoma patients (n=137), and acute-on-chronic liver failure patients related to HBV (ACLF, n=202). Serum anti-HDV-IgM and anti-HDV-IgG were uniformly tested using ELISA kits.
Research Findings:
The prevalence of HDV infection was highest among ACLF patients, at 5.9% (12/202), followed by liver cirrhosis patients with an HDV infection rate of 2.3% (5/216), hepatocellular carcinoma patients with a rate of 2.2% (3/137), and chronic hepatitis B patients with a rate of 0.4% (1/263). No HDV-positive results were found among HBV carriers.
Research Conclusion:
The results of this study indicate that there is variation in the prevalence of HDV infection among chronic HBV-infected individuals at different disease stages or severity levels. Patients co-infected with HDV are more likely to progress to severe liver diseases and have an increased risk of developing acute-on-chronic liver failure. Therefore, clinicians should actively conduct relevant laboratory tests to determine the presence of co-existing HDV infection when diagnosing and treating severe liver diseases or end-stage liver diseases caused by chronic HBV infection, especially in cases of acute-on-chronic liver failure.
HDV RNA is a direct marker for confirming hepatitis D virus infection and viral replication activity, serving as the “gold standard” for diagnosing viremia in HDV infection. Quantitative measurement of HDV RNA can also be used to assess the need for antiviral therapy and monitor the response to antiviral treatment. One limitation of this study is the lack of further testing for HDV RNA, mainly due to the absence of commercially available approved HDV RNA quantification assay kits in China at the time of the study.
Additionally, as this study was conducted at a single center, the exact prevalence of HDV in different regions of China and among chronic HBV-infected individuals at various disease stages may require confirmation through multicenter, larger-scale clinical research data.
In conclusion, this research underscores the importance of considering HDV co-infection as a significant factor in the progression and management of chronic HBV-related liver diseases, and highlights the need for further studies to better understand the prevalence and impact of HDV infection in different populations and regions.
TAG: APASL 2023, Voice of China, HBV/HDV
