Evidence That both HIV and HIV-Induced Immunodeficiency Enhance HCV Replication among HCV Seroconverters

AbstractThe objective of this retrospective cohort study is to assess the mechanism by which human immunodeficiency virus type 1 (HIV) influences hepatitis C virus (HCV) replication in injecting drug users. Virological (HCV and HIV RNA levels) and immunological (CD4+, CD8+cell counts, and anti-CD3 reactivity) parameters were determined in 19 HCV seroconverters in sequential samples over a period of 1 to 9 years. Among these subjects, 10 were HIV-seronegative (HIVneg), 4 were HIV-seropositive (HIVpos), and 5 seroconverted for HIV (HIVsc) during the observation period. HCV RNA levels were higher in HIVpos subjects than in HIVneg subjects. In subjects seroconverting for HIV, HCV RNA levels increased significantly immediately after HIV seroconversion (P< 0.0001), while they remained stable over time in HIVpos and HIVneg subjects. HCV RNA correlated inversely with CD4+cell counts in both the HIVpos population (R= −0.22,P< 0.05) and the HIVneg population (R= −0.45,P< 0.0001). In addition, when subjects were stratified according to CD4+cell counts a significant difference was found in HCV RNA levels between HIVpos and HIVneg subjects with CD4+cell counts >500 cells/μl (P= 0.001), but not in the population with CD4+cell counts