Increased platelet and microparticle activation in HIV infection: upregulation of P-selectin and tissue factor expression

J Acquir Immune Defic Syndr. 2012 Apr 1;59(4):340-6. doi: 10.1097/QAI.0b013e3182439355.


Objective: HIV-1-infected patients have an increased risk for atherothrombosis and cardiovascular disease, but the mechanism behind these risks is poorly understood. We have previously reported that expression of tissue factor (TF) on circulating monocytes is increased in persons with HIV infection and that TF expression is related to immune activation, to levels of HIV in plasma, and to indices of microbial translocation. In this study, we explore the activation state of platelets in HIV disease.

Methods: Here, using flow cytometry-based assays, we measured platelet and platelet microparticle (PMP) activation in samples from HIV-1-infected donors and controls.

Results: Platelets and PMPs from HIV-1-infected patients are activated (as reflected by expression of CD62 P-selectin) and also more frequently expressed the procoagulant TF than did platelets and PMPs obtained from controls. Expression of these proteins was directly related to expression of TF on monocytes, to markers of T-cell activation (CD38 and HLA-DR), and to plasma levels of soluble CD14, the coreceptor for bacterial lipopolysaccharride. Platelet and microparticle expression of TF was not related to plasma levels of HIV but expression of P-selectin was related to plasma levels of HIV; neither TF nor P-selectin expression was related to CD4 T-cell count.

Conclusions: Platelets and microparticles are activated in HIV infection, and this activated phenotype may contribute to the increased risk for cardiovascular and thrombotic events in this population although a role for other confounding cardiovascular risks cannot be completely excluded.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • ADP-ribosyl Cyclase 1 / biosynthesis
  • Adult
  • Aged
  • Blood Platelets / virology*
  • CD4 Lymphocyte Count
  • Cell-Derived Microparticles / virology*
  • Female
  • Flow Cytometry
  • HIV Infections / metabolism*
  • HLA-DR Antigens / biosynthesis
  • Humans
  • Lipopolysaccharide Receptors / blood
  • Lymphocyte Activation
  • Male
  • Membrane Glycoproteins / biosynthesis
  • Middle Aged
  • Monocytes / metabolism
  • P-Selectin / biosynthesis*
  • Platelet Activation*
  • Thromboplastin / biosynthesis*
  • Up-Regulation
  • Young Adult


  • HLA-DR Antigens
  • Lipopolysaccharide Receptors
  • Membrane Glycoproteins
  • P-Selectin
  • Thromboplastin
  • CD38 protein, human
  • ADP-ribosyl Cyclase 1