Protein S and HIV infection. The role of anticardiolipin and anti-protein S antibodies.
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.
Sorice
M
M
Dip. Medicina Sperimentale, Università La Sapienza, Roma, Italy.
Griggi
T
T
Arcieri
P
P
Circella
A
A
d'Agostino
F
F
Ranieri
M
M
Modrzewska
R
R
Lenti
L
L
Mariani
G
G
D000163:Acquired Immunodeficiency Syndrome / Q000097:blood / Q000276:immunology; D000328:Adult; D017153:Antibodies, Anticardiolipin / Q000097:blood / Q000276:immunology*; D016736:Antiphospholipid Syndrome / Q000150:complications; D001323:Autoantibodies / Q000097:blood / Q000276:immunology*; D015496:CD4-Positive T-Lymphocytes; D004198:Disease Susceptibility / Q000276:immunology; D005260:Female; D015658:HIV Infections / Q000097:blood* / Q000276:immunology; D015497:HIV-1; D006801:Humans; D007958:Leukocyte Count; D008297:Male; D017293:Protein S / Q000276:immunology; D018455:Protein S Deficiency; D013923:Thromboembolism / Q000209:etiology*
D017153:Antibodies, Anticardiolipin; D001323:Autoantibodies; D017293:Protein S