Relationship between T cell activation and CD4+ T cell count in HIV-seropositive individuals with undetectable plasma HIV RNA levels in the absence of therapy

J Infect Dis. 2008 Jan 1;197(1):126-33. doi: 10.1086/524143.

Abstract

Background: Although untreated human immunodeficiency virus (HIV)-infected patients maintaining undetectable plasma HIV RNA levels (elite controllers) have high HIV-specific immune responses, it is unclear whether they experience abnormal levels of T cell activation, potentially contributing to immunodeficiency.

Methods: We compared percentages of activated (CD38(+)HLA-DR(+)) T cells between 30 elite controllers, 47 HIV-uninfected individuals, 187 HIV-infected individuals with undetectable viremia receiving antiretroviral therapy (antiretroviral therapy suppressed), and 66 untreated HIV-infected individuals with detectable viremia. Because mucosal translocation of bacterial products may contribute to T cell activation in HIV infection, we also measured plasma lipopolysaccharide (LPS) levels.

Results: Although the median CD4(+) cell count in controllers was 727 cells/mm(3), 3 (10%) had CD4(+) cell counts <350 cells/mm(3) and 2 (7%) had acquired immunodeficiency syndrome. Controllers had higher CD4(+) and CD8(+) cell activation levels (P < .001 for both) than HIV-negative subjects and higher CD8(+) cell activation levels than the antiretroviral therapy suppressed (P = .048). In controllers, higher CD4(+) and CD8(+) T cell activation was associated with lower CD4(+) cell counts (P = .009 and P = .047). Controllers had higher LPS levels than HIV-negative subjects (P < .001), and in controllers higher LPS level was associated with higher CD8(+) T cell activation (P = .039).

Conclusion: HIV controllers have abnormally high T cell activation levels, which may contribute to progressive CD4(+) T cell loss even without measurable viremia.

Publication types

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

MeSH terms

  • Adult
  • CD4 Lymphocyte Count
  • Cohort Studies
  • Female
  • HIV Infections / immunology*
  • HIV Seropositivity / immunology*
  • HIV-1 / immunology*
  • Humans
  • Lymphocyte Activation*
  • Male
  • Middle Aged
  • RNA, Viral / blood*
  • T-Lymphocytes / immunology
  • T-Lymphocytes / virology*
  • Viremia / immunology

Substances

  • RNA, Viral