• Underlying patterns of liver injury and hepatitis C virus (HCV) viral changes after antiretroviral therapy (ART) initiation [ Time Frame: Throughout study ] [ Designated as safety issue: Yes ]
  

Coinfection with HCV and HIV occurs in 20% to 30% of HIV infected people in the United States. Individuals with HCV/HIV coinfection tend to have higher HCV viral loads than individuals with HCV alone. However, current evidence suggests that initiation of effective antiretroviral therapy (ART) may be associated with increases in HCV viral load. The purpose of this study is to evaluate changes in HCV viral load associated with the initiation of ART in HCV/HIV coinfected adults. All participants will receive ART consisting of efavirenz once daily and the coformulation of emtricitabine and tenofovir DF once daily. If participants are unable to tolerate a different regimen would be prescribed. There will be at least 21 study visits. During the first week of the study, participants will undergo blood draws for viral kinetic sampling and initiation of study medications. Following the first week, there will be weekly visits for 96 weeks. At screening, participants will undergo vital signs measurements, a physical exam, medical history, blood collection, and liver biopsy. During Week 1, participants will be hospitalized for 24 hours for initiation of ART and viral kinetic sampling. Blood draws for viral kinetic sampling of HCV and HIV will be performed at Hours 0, 2, 4, 6, 9, 12, 18, and 24. Participants will return to the clinic or hospital at Hours 48, 72, 96, and 167 for additional viral kinetic sampling. Blood collection will occur at all visits; physical exams, vital signs measurement, a side effects questionnaire, and urine and semen collection will occur at selected visits.