• HEPATITIS B
• HEPATITIS C

Several convincing lines of evidence have shown that effective antiviral treatment of patients with chronic hepatitis B (HBV) or C (HCV) can positively affect the natural course of both diseases. Indeed, maintained HBV suppression by pegylated interferon (PegIFN) or nucleos(t)ide analogue treatment has been shown to reduce the risk of hepatocellular carcinoma (HCC), eliminate the risk of liver decompensation, and improve overall survival.1 The same holds true for HCV, where viral eradication achieved by IFN or by directly acting antiviral-based therapy abolishes the risk of progression to cirrhosis and reduces, or abrogates, the risk of liver-related complications in patients with cirrhosis.1 Unfortunately, less is known about the impact of antiviral therapy in patients co-infected with both viruses. This is not a rare event, as in most countries HBV and HCV share modalities of transmission; currently it is estimated that nearly 5–20% of HBV patients and 2–10% of HCV patients have HBV–HCV co-infection.2 From a clinical standpoint, HBV–HCV co-infection has been associated with increased risk of fulminant hepatitis in the acute phase and development of cirrhosis and HCC in the long term.3 Still this has not been confirmed in all studies, probably because of significant differences in terms of ethnicity, comorbid conditions and virological profiles among the analysed cohorts.4 Patients with HBV–HCV co-infection are indeed extremely heterogeneous both in terms of infection modality—with most patients from Asia acquiring HBV infection at birth and later having HCV superinfection, whereas patients from Europe and the USA often acquire both infections concomitantly—and in terms of viral dominance of one virus over the other. …