HCV/HIV Coinfection: Antiviral Therapy and Fibrosis

Inclusion Criteria: Co-Infected Arm 1. Subject must be an HIV/HCV co-infected adult with HIV infection diagnosed by antibody testing and chronic HCV infection diagnosed by reactive HCV antibody and detectable plasma HCV RNA. 2. Subject must receive medical care at the JHU HIV clinic or through the Viral Hepatitis Center. 3. Subjects previously enrolled in the study cohort, but not currently receiving care in the Moore Clinic, may continue in the study. 4. Females of childbearing potential must be willing to undergo a urine or serum pregnancy test. 5. Subject must be able to provide informed written consent. Control Arm 1. Subject must have or be at risk of having medical conditions that increase the risk of liver disease. These include, but are not limited to, HIV mono-infection, HCV mono-infection, Hepatitis B infection, alcohol addiction, and/or non-alcoholic steatohepatitis. 2. Females of childbearing potential must be willing to undergo a urine or serum pregnancy test. 3. Subject must be able to provide informed written consent. Exclusion Criteria: 1. To avoid risks associated with ionizing radiation, female subjects may not be pregnant or breast feeding at the time of DEXA scanning. To avoid unknown risks to the fetus, female subjects may not be pregnant at the time of liver biopsy or FibroScan. 2. To avoid interference with the DEXA scan, the subject may not have undergone a nuclear medicine exam with the past week and/or may not have undergone an x-ray procedure with contrast solution within the past 72 hours. 3. To avoid unknown risks, subjects with an implanted cardiac device such as a defibrillator or pacemaker may not undergo FibroScan.