Association of HIV neutralizing antibody with lower viral load after treatment interruption in a prospective trial (A5170)

AIDS. 2012 Jan 2;26(1):1-9. doi: 10.1097/QAD.0b013e32834d606e.


Objective: We investigated the impact of neutralizing antibodies (NAbs) on CD4 T-cell count and viral load in a cohort of HAART recipients who underwent extended structured treatment interruption.

Design: Substudy of NAb in the AIDS Clinical Trials Group 5170 trial.

Methods: Early plasma samples from 50 volunteers who discontinued HAART were evaluated in a peripheral blood mononuclear cell-based neutralization assay against a panel of four subtype B primary isolates.

Results: We found that high-titer (90% inhibitory dose > 500) NAb against two or more isolates was associated with reduced viral load (P = 0.003 at 12-week posttreatment interruption). This effect faded with time, losing significance (P = 0.161) by study conclusion. Participants possessing the highest NAb levels against individual isolates appeared more likely to have lower viral loads with the association gaining significance against the R5-tropic primary isolate US1 (P = 0.005). There was no association between broader neutralization and CD4 T-cell slope over time.

Conclusion: The data suggest that high-titer NAb responses at the time of treatment interruption are associated with reduced viral load over time, but not CD4(+) T-cell decline.

Publication types

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

MeSH terms

  • Adult
  • Antibodies, Neutralizing / blood
  • Antibodies, Neutralizing / drug effects
  • Antibodies, Neutralizing / immunology*
  • Antiretroviral Therapy, Highly Active
  • CD4 Lymphocyte Count
  • CD4-Positive T-Lymphocytes / immunology*
  • Cohort Studies
  • Female
  • HIV Antibodies / blood
  • HIV Antibodies / drug effects
  • HIV Antibodies / immunology*
  • HIV Infections / blood
  • HIV Infections / drug therapy
  • HIV Infections / immunology*
  • HIV-1 / immunology*
  • Humans
  • Male
  • Neutralization Tests
  • Prospective Studies
  • RNA, Viral / blood
  • Treatment Outcome
  • Viral Load / immunology*
  • Withholding Treatment


  • Antibodies, Neutralizing
  • HIV Antibodies
  • RNA, Viral