title: Sex differences in HIV-1 viral load and progression to AIDS.
abstract: BACKGROUND
  Plasma HIV-1 RNA measurements are used for initiation of antiretroviral treatments. Whether the viral-load association with prognosis is similar in women and men is unknown.
  
  
  METHODS
  We studied 812 specimens from 650 injection-drug users (IDUs) participating in a continuous observational study of patients based in a community clinic. HIV-1 load was measured by branched-chain DNA on samples from 527 IDUs from the baseline visit, and by reverse-transcriptase PCR and quantitative microculture on samples from 285 IDUs at a follow-up visit 3 years later. FNDINGS: Women had lower median viral-load measurements than men by branched-chain DNA (3365 vs 8907 copies/mL; p=0.001), reverse-transcriptase PCR (45416 vs 93130 copies/mL; p=0.02), and quantitative microculture (5 vs 8 infectious units per million peripheral blood mononuclear cells; p=0.015). This association remained even after adjustment for CD4 cell count, race, and drug use within the previous 6 months. Time to AIDS was statistically similar for men and women in a univariate proportional-hazards model and in a model adjusting for CD4 cell count. Proportional-hazards models showed that women with the same viral load as men had a 1.6-fold higher risk of AIDS (95% CI 1.10-2.32); or, equivalently, that women with half the viral load of men had a similar time to AIDS as men.
  
  
  CONCLUSIONS
  Although a biological mechanism remains unclear, these data suggest that current recommendations for HIV-1 viral-load thresholds to initiate antiretroviral therapy should be revised downwards for women.
authors.affiliation: Department of Epidemiology, Johns Hopkins School of Hygiene and Public Health, Baltimore, MD 21205, USA. hfarzade@jhsph.edu
authors.forename: H
authors.initials: H
authors.lastname: Farzadegan
authors.forename: D R
authors.initials: DR
authors.lastname: Hoover
authors.forename: J
authors.initials: J
authors.lastname: Astemborski
authors.forename: C M
authors.initials: CM
authors.lastname: Lyles
authors.forename: J B
authors.initials: JB
authors.lastname: Margolick
authors.forename: R B
authors.initials: RB
authors.lastname: Markham
authors.forename: T C
authors.initials: TC
authors.lastname: Quinn
authors.forename: D
authors.initials: D
authors.lastname: Vlahov
mesh_terms: D000163:Acquired Immunodeficiency Syndrome / Q000453:epidemiology*; D018791:CD4 Lymphocyte Count; D016022:Case-Control Studies; D018450:Disease Progression; D005260:Female; D015658:HIV Infections / Q000097:blood / Q000453:epidemiology / Q000821:virology*; D015497:HIV-1 / Q000302:isolation & purification*; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D011379:Prognosis; D016016:Proportional Hazards Models; D012367:RNA, Viral / Q000097:blood; D012307:Risk Factors; D012737:Sex Factors; D015819:Substance Abuse, Intravenous / Q000150:complications; D015996:Survival Rate; D013997:Time Factors; D019562:Viral Load
chemical_list: D012367:RNA, Viral