• hepatitis B virus;
  • hepatitis C virus;
  • hepatitis D virus;
  • multiple infection

In patients with multiple hepatotropic viral infections (B and C, or B, C and D), the reciprocal influence of each virus remains controversial. The aims of this study were twofold: first, to determine the impact of multiple infection on the replication status of B, C and D viruses and on histological features; and second, to compare patients with multiple infection to patients infected only with the hepatitis C virus (HCV). We retrospectively included 50 patients with multiple infection and 50 control HCV patients, who were matched on independent factors associated with fibrosis, such as age, gender, alcohol consumption and duration of infection. The replication status of hepatitis B virus (HBV), HCV and hepatitis D virus (HDV), and histological lesions, were determined. In patients with multiple infection, HCV RNA was present less frequently (44% vs 98%, P < 0.001) and the prevalence of cirrhosis was higher (35% vs 8%, P < 0.001). Among patients with triple infection (n = 16), HBV replication was observed in 25%, HCV RNA was detectable in only two (P < 0.0001) and HCV viremia was significantly lower than in the matched HCV patients (0 vs 54.7, P < 0.0001). Among patients with dual infection (n = 34), HCV RNA was present less frequently in those with serological markers of active HBV infection than in those without (30% vs 79%, P = 0.01). Hence, multiple infection is associated with a decrease of HCV replication. Cirrhosis seems to be more frequently observed in patients with multiple infection. In patients with triple infection, serum HCV RNA and markers of HBV replication were absent in 80%, suggesting that HDV acts as a dominant virus. In patients with dual infection, HBV and HCV exert an alternative, dominant replication.