title: Copy-years viremia as a measure of cumulative human immunodeficiency virus viral burden.
abstract: Plasma human immunodeficiency virus type 1 (HIV-1) viral load is a valuable tool for HIV research and clinical care but is often used in a noncumulative manner. The authors developed copy-years viremia as a measure of cumulative plasma HIV-1 viral load exposure among 297 HIV seroconverters from the Multicenter AIDS Cohort Study (1984-1996). Men were followed from seroconversion to incident acquired immunodeficiency syndrome (AIDS), death, or the beginning of the combination antiretroviral therapy era (January 1, 1996); the median duration of follow-up was 4.6 years (interquartile range (IQR), 2.7-6.5). The median viral load and level of copy-years viremia over 2,281 semiannual follow-up assessments were 29,628 copies/mL (IQR, 8,547-80,210) and 63,659 copies x years/mL (IQR, 15,935-180,341). A total of 127 men developed AIDS or died, and 170 survived AIDS-free and were censored on January 1, 1996, or lost to follow-up. Rank correlations between copy-years viremia and other measures of viral load were 0.56-0.87. Each log(10) increase in copy-years viremia was associated with a 1.70-fold increased hazard (95% confidence interval: 0.94, 3.07) of AIDS or death, independently of infection duration, age, race, CD4 cell count, set-point, peak viral load, or most recent viral load. Copy-years viremia, a novel measure of cumulative viral burden, may provide prognostic information beyond traditional single measures of viremia.
authors.affiliation: Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, NC 27599-7435, USA. cole@unc.edu
authors.forename: Stephen R
authors.initials: SR
authors.lastname: Cole
authors.forename: Sonia
authors.initials: S
authors.lastname: Napravnik
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Mugavero
authors.forename: Bryan
authors.initials: B
authors.lastname: Lau
authors.forename: Joseph J
authors.initials: JJ
authors.lastname: Eron
authors.forename: Michael S
authors.initials: MS
authors.lastname: Saag
mesh_terms: D000328:Adult; D015658:HIV Infections / Q000097:blood*; D015497:HIV-1; D006801:Humans; D008297:Male; D019562:Viral Load; D014766:Viremia / Q000097:blood*