Hepatitis D virus Antigen (HDV-Ag) ELISA Kit

Short Description:

Hepatitis D virus (HDV) is a defective, single-stranded RNA virus that requires the hepatitis B virus (HBV) for its replication and assembly, as it relies on HBV’s surface antigen (HBsAg) to form its envelope. It cannot replicate independently and must be accompanied or preceded by HBV infection. HDV is transmitted primarily through parenteral routes, such as exposure to infected blood or blood products (e.g., via transfusion or needle sharing among intravenous drug users), but also through sexual contact, close household contact, and vertical transmission from mother to child. HDV infection has a global distribution, with higher endemicity in regions such as Central and West Africa, the Amazon Basin, Central Asia, the Middle East, and parts of Eastern Europe and the Pacific Islands; prevalence has declined in some areas like Southern Italy due to HBV vaccination and improved hygiene.

Co-infection occurs when HDV and HBV are acquired simultaneously, often leading to acute hepatitis that may resolve or progress to chronicity. Superinfection refers to HDV infection in individuals with pre-existing chronic HBV, which frequently results in more severe outcomes. Clinical studies demonstrate that HDV infection exacerbates HBV-related liver disease, accelerating progression to cirrhosis, liver failure, and hepatocellular carcinoma, and it is a major contributor to fulminant hepatic failure in co-infected or superinfected patients.

The HDV antigen (HDAg), also known as delta antigen, is a key viral protein expressed during active HDV replication within hepatocytes. Detection of HDAg in serum, plasma, or liver tissue serves as a direct marker of ongoing viral infection and replication, particularly useful in diagnosing acute HDV infection where it appears early (often within days of symptom onset) and may persist transiently. In chronic HDV cases, HDAg detection can indicate persistent viral activity, especially in HBV/HDV co-infected patients, aiding in monitoring disease severity, guiding antiviral therapy, and assessing treatment response. Unlike antibody tests, antigen detection provides evidence of current infection rather than past exposure or immunity.