Lower CD4 cell count and higher virus load, but not antiretroviral drug resistance, are associated with AIDS-defining events and mortality: an ACTG Longitudinal Linked Randomized Trials (ALLRT) analysis

HIV Clin Trials. Mar-Apr 2011;12(2):79-88. doi: 10.1310/hct1202-79.


Background: We hypothesized that drug resistance mutations would impact clinical outcomes associated with HIV-1 infection.

Methods: A matched case-control study of participants in AIDS Clinical Trials Group Longitudinal Linked Randomized Trials (ALLRT). Cases experienced an AIDS-defining event (ADE) or mortality, and controls did not. One hundred thirty-four cases were identified and matched to a total of 266 controls by age, sex, treatment regimen, and length of follow-up. Both cases and controls had HIV RNA levels of ≥ 500 copies/mL within 24 weeks of an event. Population-based genotyping at or near the time of the event was used to evaluate the impact of resistance mutations on incidence of ADE and/or death using conditional logistic regression models.

Results: One hundred four cases and 183 controls were analyzed. Median time to event was 99 weeks; 6 cases were deaths. At baseline, cases had lower CD4 (median 117 vs 235 cells/mm3; P < .0001) and higher HIV RNA levels (median 205,000 vs 57,000 copies/mL; P = .003). No significant differences in resistance were seen between cases and controls.

Conclusions: In this rigorously designed case-control study, lower CD4 cell counts and higher virus loads, not antiretroviral drug resistance, were strongly associated with ADE and mortality.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acquired Immunodeficiency Syndrome / drug therapy
  • Acquired Immunodeficiency Syndrome / immunology
  • Acquired Immunodeficiency Syndrome / mortality*
  • Acquired Immunodeficiency Syndrome / virology
  • Adult
  • CD4 Lymphocyte Count*
  • Case-Control Studies
  • Drug Resistance, Viral
  • Female
  • Humans
  • Logistic Models
  • Longitudinal Studies
  • Male
  • Randomized Controlled Trials as Topic
  • Retrospective Studies
  • Viral Load*