HIV-HBV and HIV-HCV coinfection and liver cancer development.

Liver diseases caused by chronic HBV or HCV infection, including cirrhosis and HCC, are emerging as an increasingly important problem faced by millions of HIV-infected patients who are coinfected with HBV or HCV. On one hand, HIV-induced immune suppression enhances the risk of chronic viral hepatitis, increases HBV or HCV load, and may hasten the progression to cirrhosis and liver cancer. On the other hand, significant hepatotoxicity is associated with a number of antiretroviral drugs, further exacerbating liver damage associated with chronic viral hepatitis. The exact risk of HCC in HIV and HBV or HCV coinfected patients remains to be fully assessed. The elucidation of the multiple virus-virus and virus-host interactions that underlie viral hepatocarcinogenesis and potential HIV enhancement awaits the establishment of appropriate in vitro and in vivo model systems. As millions of HIV-infected patients in the developing countries are gaining access to HAART therapy for their HIV infections, endemic HBV and HCV infections and their associated liver diseases will only become more problematic on a global level. To ameliorate the suffering from HBV- and HCV-induced liver cancer in HIV patients, more effective treatment for chronic HBV and HCV infections are needed. The long time frame of viral hepatocarcinogenesis may afford a window of opportunity to develop and improve such treatment.