Background: Higher high-density lipoprotein concentrations are associated with a better disease course in HIV-infected patients. Paraoxonase-1, an enzyme contained within high-density lipoproteins, is thought to hydrolyse oxidised lipids. The aim of the present study was to investigate the relationships between HIV infection and the circulating activity and concentration of paraoxonase-1, and the concentration of high-density lipoproteins, apolipoprotein A-I and oxidised low-density lipoproteins.
Methods: We studied patients with HIV infection (n=212) and healthy subjects (n=409). In all the participants we measured the relevant biochemical and genetic variables. The statistical associations between these variables and paraoxonase-1 activity and concentration were assessed using multiple linear regression analysis.
Results: Serum paraoxonase-1 activity was decreased (P<0.001) and its concentration was increased (P=0.017) in HIV-patients compared to the controls. HIV infected patients had lower HDL-cholesterol and apolipoprotein A-I concentrations. Multivariate regression analysis showed that serum paraoxonase-1 activity was associated with the CD4+ T lymphocyte count (P<0.05), apolipoprotein A-I (P<0.001), and paraoxonase-1 genetic polymorphisms (P<0.001). Paraoxonase-1 concentration was associated with that of serum beta-2-microglobulin (P<0.001).
Conclusions: Both, paraoxonase-1 activity and concentration were influenced by HIV-infection and these were related to alterations in HDL composition and the immunological status of the patients.