What is the meaning of HDV coinfection or superinfection?

Author: Prof. Jean-François Dufour

Updated: 10 / 2007

Answer:

HDV depends on the synthesis of HBsAg for its assembly, therefore, HDV infection is limited to HBsAg-positive patients. HDV infection may either occur at the same time as HBV (coinfection) or in patients with a pre-existing HBV infection (superinfection). Usually, HDV suppresses HBV replication. Although the risk of acute liver failure is increased, the overall prognosis of HDV/HBV coinfection is good, as the risk of persistent infection is low (<5%).

Clinically, HDV infection may be indistinguishable from acute hepatitis B. A two-phase peak of aminotransferases may be observed in cases of HDV infection. The HDV superinfection of a patient infected with chronic HBV may present as an acute liver failure. In addition, this condition is usually followed by the establishment of chronic HDV infection and hepatitis. In case of acute hepatitis in a chronic HBV carrier, the possibility of HDV superinfection should be considered. The diagnosis is based on the evidence of markers of HDV (HDV serology, quantitative RT-PCR) in the absence of anti-HBc IgM. As the HDV infection suppresses HBV replication, HBeAg and HBV DNA are usually negative. Chronic hepatitis due to HDV evolves more rapidly towards cirrhosis. HDV increases the risk of developing a hepatocellular carcinoma by a factor of 3 in comparison to patients with only HBV-induced cirrhosis.

References:

Fattovich G, Giustina G, Christensen E et al. Influence of hepatitis delta virus infection on morbidity and mortality in compensated cirrhosis type B. The European Concerted Action on Viral Hepatitis (Eurohep). Gut 2000;46:420-6.