Hepatitis A virus infection suppresses hepatitis C virus replication and may lead to clearance of HCV.

Background/aims: The significance of hepatitis A virus (HAV) super-infection in patients with chronic hepatitis C had been a matter of debate. While some studies suggested an incidence of fulminant hepatitis A of up to 35%, this could not be confirmed by others.
Methods: We identified 17 anti-HCV-positive patients with acute hepatitis A from a cohort of 3170 anti-HCV-positive patients recruited at a single center over a period of 12 years.
Results: Importantly, none of the anti-HCV-positive patients had a fulminant course of hepatitis A. HCV-RNA was detected by PCR in 84% of the anti-HCV-positive/anti-HAV-IgM-negative patients but only in 65% of anti-HCV-positive patients with acute hepatitis A (p=0.03), indicating suppression of HCV replication during hepatitis A. Previous HAV infection had no effect on HCV replication. After recovery from hepatitis A, an increased HCV replication could be demonstrated for 6 out of 9 patients with serial quantitative HCV-RNA values available while 2 patients remained HCV-RNA negative after clearance of HAV throughout follow-up of at least 2 years.
Conclusions: HAV super-infection is associated with decreased HCV-RNA replication which may lead to recovery from HCV in some individuals. Fulminant hepatitis A is not frequent in patients with chronic hepatitis C recruited at a tertiary referral center.