This ACTG trial is a prospective study of subjects co-enrolled in other antiretroviral studies receiving highly antiretroviral therapy (HAART)and who have HIV-1 RNA plasma viral loads of >2,500 copies/ml. Subjects will be evaluated for HCV RNA at specific intervals. The dynamics of hepatitis C viremia by quantitative HCV RNA will be determined in individuals co-infected with HIV who exhibit a reduction in HIV-1 RNA levels of <500 copies/ml at 16 weeks of HAART for HIV. Secondary objectives are to determine if there is a difference in the change of hepatitis C viremia and to determine the changes in ALT. If there are changes in HCV RNA levels, these changes will be correlated to changes in inducible IFN-gamma and IL-4 in PBMC's. Changes in HCV RNA levels will be correlated to CD4 changes.