In Reply: We thank Dr. Homler for bringing hepatitis D as a potential cause of acute liver failure to our attention.
Hepatitis D virus, first described in the 1970s, requires the hepatitis B surface antigen (HBsAg) capsid to enter the hepatocyte and, thus, can only cause liver injury when the patient is also infected simultaneously with hepatitis B virus. 1 Hepatitis D virus can cause either coinfection (presence of immunoglobulin M anti-HB core antibody with or without HBsAg) or superinfection (presence of HBsAg without immunoglobulin M anti-HB core antibody) with hepatitis B virus. In India, coinfection has been reported to be the cause of acute liver failure in about 4% of all patients, and superinfection in 4.5%. 2
While simultaneous treatment for hepatitis D and B viruses with pegylated interferon and any of the agents used for treatment of hepatitis B has been successful in treating chronic hepatitis, it has not been proven useful in patients with acute liver failure, and liver transplant remains the only treatment option. 3