Protein S and HIV infection. The role of anticardiolipin and anti-protein S antibodies

Thromb Res. 1994 Feb 15;73(3-4):165-75. doi: 10.1016/0049-3848(94)90095-7.


It has recently been reported that a large proportion of patients with HIV infection have low free protein S levels. In this study we show that protein S (PS) activity levels, as well as PS antigen (Ag), were significantly lower in 35 HIV-1 infected patients than in the control population (p < 0.001). When we divided HIV infected patients into three groups according to their CD4+ counts, we found that PS levels were significantly lower in patients with < 100 CD4+ cells/ul. In order to investigate the possible role of (auto)immune response in the pathogenesis of PS deficiency, the presence of anticardiolipin antibodies (aCL) and/or of the specific antibodies to protein S was evaluated. A high prevalence (77.1%) of aCL in both symptomatic and asymptomatic subjects was observed. The screening for specific anti-PS antibodies, performed by immunoblotting, showed an overall positivity of 28.6% in anti-HIV+ patients, with a higher prevalence in symptomatic than in asymptomatic patients. Interestingly, the prevalence of the positivity for anti-PS antibodies was found to be higher in anti-HIV+ patients with PS levels < 50%. Taken collectively, our findings suggest that at least one of the mechanisms through which PS levels are decreased in HIV infection, is due to the presence of specific autoantibodies.

Publication types

  • Comparative Study

MeSH terms

  • Acquired Immunodeficiency Syndrome / blood
  • Acquired Immunodeficiency Syndrome / immunology
  • Adult
  • Antibodies, Anticardiolipin / blood
  • Antibodies, Anticardiolipin / immunology*
  • Antiphospholipid Syndrome / complications
  • Autoantibodies / blood
  • Autoantibodies / immunology*
  • CD4-Positive T-Lymphocytes
  • Disease Susceptibility / immunology
  • Female
  • HIV Infections / blood*
  • HIV Infections / immunology
  • HIV-1
  • Humans
  • Leukocyte Count
  • Male
  • Protein S / immunology
  • Protein S Deficiency*
  • Thromboembolism / etiology*


  • Antibodies, Anticardiolipin
  • Autoantibodies
  • Protein S