HIV-1 induces in vivo platelet activation by enhancing platelet NOX2 activity

Summary Objectives HIV-1 patients show increased platelet activation, but the mechanisms involved are not completely clarified. We speculated that HIV-1 might induce in vivo platelet activation by enhancing platelet NOX2-related oxidative stress. Methods We measured soluble CD40 Ligand (sCD40L), a systemic marker of platelet activation, in 36 HIV-1 patients under effective combined antiretroviral therapy (cART) and in 10 naive HIV-1 subjects. As control, 20 healthy subjects (HS) were included. Platelet oxidative stress was measured by platelet NOX2-derived peptide (sNOX2-dp), p47 phox translocation to platelet membrane and platelet prostaglandin F 2α (8-iso-PGF 2α ). Results sCD40L was increased both in HIV-1 naive and cART patients compared to HS (p  2α were significantly higher in HIV-1 naive subjects compared to those on cART and to HS, and both were mutually correlated (R = 0.734, p  Conclusions HIV-1 infection is associated with increased platelet oxidative stress, which was related to the activation of NOX2. The independent association between platelet NOX2 activation and plasma levels of sCD40L suggest that in vivo platelet activation may be dependent upon platelet oxidative stress.