HIV-1 p24 antigen is a significant inverse correlate of CD4 T-cell change in patients with suppressed viremia under long-term antiretroviral therapy

J Acquir Immune Defic Syndr. 2003 Jul 1;33(3):292-9. doi: 10.1097/00126334-200307010-00002.


An HIV-1 p24 antigen test involving signal amplification-boosted ELISA of heat-denatured plasma was evaluated prospectively in 55 patients whose viral RNA in plasma had previously been suppressed for at least 6 months under antiretroviral combination therapy. During a median follow-up of 504 days, CD4 counts increased by a median of 62 cells per year. By univariate and multivariate linear regression analysis, the level of p24 antigen as expressed by the absorbance/cutoff ratio was a significant inverse correlate of both the CD4 count in a sample (p =.013) and its annual change in a patient (p <.0001). The p24 antigen retained significance even among 48 individuals whose HIV-1 RNA, apart from occasional blips, remained below 400 copies/mL. Batch-wise retesting of 70 samples from 5 such patients with a further improved procedure showed measurable p24 antigen in all but 1 sample and an inverse correlation with both the CD4 count (p =.0331) and percentage (p <.0001), thus confirming the prospectively generated data. Comparison of p24 antigen and HIV-1 RNA concentrations indicate that the p24 antigen detected in these samples is not associated with viral RNA-containing particles and may originate from other compartments of virus expression.

Publication types

  • Clinical Trial
  • Comparative Study
  • Multicenter Study
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Anti-HIV Agents / administration & dosage*
  • Anti-HIV Agents / therapeutic use*
  • CD4 Lymphocyte Count
  • CD4-Positive T-Lymphocytes / cytology*
  • CD4-Positive T-Lymphocytes / immunology
  • Female
  • HIV Core Protein p24 / analysis*
  • HIV Core Protein p24 / blood
  • HIV Infections / drug therapy*
  • HIV Infections / immunology*
  • HIV Infections / virology
  • HIV-1
  • Humans
  • Male
  • Middle Aged
  • Viremia / drug therapy


  • Anti-HIV Agents
  • HIV Core Protein p24