Hepatitis C virus and human immunodeficiency virus: clinical issues in coinfection.

The prevalence of hepatitis C virus (HCV) and human immunodeficiency virus (HIV) coinfection ranges from nearly 30% to over 50%, depending on the population. Shared modes of transmission and the success of current antiretroviral regimens have contributed to the emergence of HCV as a significant pathogen in the HIV-positive population. HIV coinfection appears to worsen HCV infection, with studies showing more severe fibrosis, a higher frequency of cirrhosis, and increased deaths from liver disease. HIV coinfection may also increase the rate of maternal-fetal transmission of HCV. Similarly, studies suggest a more rapid progression to AIDS or death for HCV genotypes 1a and 1b than for other genotypes in HIV-infected patients with hemophilia. Highly active antiretroviral therapy (HAART), such as HIV protease inhibitors, has no effect on HCV infection and may transiently increase ALT, AST, and hepatitis C viral load. Hepatotoxicity associated with HAART may or may not be related to the presence of HCV and may depend on the specific agents used. Data suggest that treating chronic hepatitis C in HIV-co-infected patients can decrease fibrosis, increase T-cell responsiveness to HCV antigens, and decrease the rate of fatal hepatomas. Interferon alpha may provide sustained biochemical or virologic responses in HIV/HCV-coinfected patients. The combination of interferon-alpha and ribavirin may also be a treatment option but is more complex, and additional research is needed. Treating HCV infection in HIV/HCV-coinfected individuals may help lower the hepatitis C viral load and permit treatment with protease inhibitors.