Hepatitis viruses and human immunodeficiency virus co-infection: pathogenisis and treatment

Abstract

Co-infections by hepatotropic viruses and the human immunodeficiency virus (HIV) are frequent given the shared (sexual, mother-to-child and parenteral) routes of transmission. We shall mainly develop the reciprocal interactions between the hepatitis C virus (HCV) and hepatitis B virus (HBV) since they complex diagnostic pathogenic and therapeutic issues. Interactions between HIV and HCV have been widely studied before the introduction of highly active antiretroviral therapies (HAART) [1,2] but the actual impact of HCV or HBV was limited given the severe morbidity and mortality related to HIV infection [3]. In studies conducted in the ‘AIDS era’ (pre-HAART), the late consequences of hepatitis virus-related chronic liver disease were indeed overshadowed by extra-hepatic causes of deaths, related to severe immune deficiency, namely opportunistic infections, lymphomas or wasting syndrome [4] and the impact of hepatitis virus infection on mortality of HIV-infected patients was low [3]. The development of HAART (regimens composed of nucleoside reverse transcriptase inhibitors [NRTIs], protease inhibitors [PIs] and/or non-nucleoside reverse transcriptase inhibitors [NNRTIs]) have resulted in a significant decrease in morbidity and mortality amongst HIV-infected patients [5]: this clear benefit allowed the expression of liver-related complications associated with HCV or HBV chronic infection which is mainly acquired before HIV infection, at least in hemophiliacs and injection drug users (IVDUs). Liver disease is nowadays one of the leading causes of morbidity and mortality in co-infected patients [6]. Several non-exclusive pathogenic processes that include drug-related hepatotoxicities, chronic hepatitis B (HBV) or C (HCV) infection, other liver diseases such as steatosis or non-alcoholic steato-hepatitis (NASH) and other liver diseases that are common in the setting of alcohol or drug abuse explain the increasing rate of liver complications associated with HCV-related liver disease. They account for around 9% of morbidity and 5% of mortality in HIV‐HCV co-infected patients [7] with a rise paralleling that observed in the general population [8], even though it has been suggested that HAART and especially protease inhibitors may decrease the severity of the liver disease and the liverrelated mortality [9].