Targeting Platelets in Chronic HIV Infection

Summary

Advances in antiretroviral therapy (ART) have resulted in increased survival of the HIV-infected population; however, this gain in longevity is associated with an increased risk of cardiovascular disease (CVD). Although ART and traditional risk factors contribute to CVD in this population, heightened markers of immune activation, inflammation, and coagulation independently predict morbidity and mortality, suggesting that dysregulation of these systems plays a significant role in the increased risk of CVD. The investigators believe that platelet activation is an important driver in HIV-associated immune activation, inflammation, and coagulation, leading to an increased CVD pathophysiology and risk. Platelets initiate thrombus formation and also play a key role in vascular inflammation by releasing pro-inflammatory mediators and cross-talking with other relevant cell types including leukocytes. Researchers have described platelet hyperreactivity in chronic HIV infection. Importantly, the investigators demonstrated that one week of anti-platelet therapy (aspirin) decreased platelet activation and immune activation, with an improved trend in inflammation and immune parameters. The overall hypothesis is that platelet activation is a major driver of immune activation, inflammation, and thrombosis in ART-treated HIV infected patients. The purpose of the proposed proof-of-concept study is to understand the mechanism(s) by which anti-platelet therapy improves immune and inflammatory parameters in chronic HIV infection. To test this, the immune modulating and anti-inflammatory effects of 24 weeks of the anti-platelet drug aspirin as compared to the anti-platelet drug clopidogrel will be evaluated. Given their different mechanisms of action and inhibitory potency, the investigators can differentiate whether the potential benefits are mediated via inhibition of arachidonic acid (aspirin) or inhibition of ADP (clopidogrel) or by the antithrombotic activity. A secondary goal is to perform multidimensional assays of platelet activity and thrombogenicity alongside immune activation assays and careful assessments of traditional risk factors and medication regimens, to understand which parameters are highly associated with thrombogenicity.

Timeline

Start

2015-10

Primary completion

2016-11

Completion

2016-11

Publications

• Background O'Brien M, Montenont E, Hu L, Nardi MA, Valdes V, Merolla M, Gettenberg G, Cavanagh K, Aberg JA, Bhardwaj N, Berger JS. Aspirin attenuates platelet activation and immune activation in HIV-1-infected subjects on antiretroviral therapy: a pilot study. J Acquir Immune Defic Syndr. 2013 Jul 1;63(3):280-8. doi: 10.1097/QAI.0b013e31828a292c.
• Background Miller EA, Gopal R, Valdes V, Berger JS, Bhardwaj N, O'Brien MP. Soluble CD40 ligand contributes to dendritic cell-mediated T-cell dysfunction in HIV-1 infection. AIDS. 2015 Jul 17;29(11):1287-96. doi: 10.1097/QAD.0000000000000698.
• Background Viswanathan GN, Marshall SM, Balasubramaniam K, Badimon JJ, Zaman AG. Differences in thrombus structure and kinetics in patients with type 2 diabetes mellitus after non ST elevation acute coronary syndrome. Thromb Res. 2014 May;133(5):880-5. doi: 10.1016/j.thromres.2014.01.033. Epub 2014 Feb 1.
• Background Hutter R, Speidl WS, Valdiviezo C, Sauter B, Corti R, Fuster V, Badimon JJ. Macrophages transmit potent proangiogenic effects of oxLDL in vitro and in vivo involving HIF-1alpha activation: a novel aspect of angiogenesis in atherosclerosis. J Cardiovasc Transl Res. 2013 Aug;6(4):558-69. doi: 10.1007/s12265-013-9469-9. Epub 2013 May 10.
• Background Arazi HC, Badimon JJ. Anti-inflammatory effects of anti-platelet treatment in atherosclerosis. Curr Pharm Des. 2012;18(28):4311-25. doi: 10.2174/138161212802481264.

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