Journal of Infectious Diseases & Preventive Medicine
Open Access

Abstract

In Vivo Effects of Tenofovir-DF/Emtricitabine and Abacavir/Lamivudine with Atazanavir-R on Platelet Activating Factor Metabolism in HIV Naive Patients

Vasiliki D Papakonstantinou, Maria Chini, Nikos Mangafas, George Stamatakis, Athina Lioni, Nickolaos Tsogas, Elizabeth Fragopoulou, Panagiotis Gargalianos-Kakolyris, Constantinos A Demopoulos, Smaragdi Antonopoulou and Marios C Lazanas

Antiretroviral therapy (ΑRT) has successfully decreased AIDS morbidity and mortality and increased the lifespan of HIV patients to several decades. However, numerous factors contribute with unknown mechanisms to chronic immune activation and inflammation leading to severe “non-AIDS morbidities’’. Platelet Activating Factor (PAF) is a potent lipid inflammatory mediator with important role in the ‘’non-AIDS morbidities’’. The purpose of this study was to investigate whether tenofovir-DF/emtricitabine and abacavir/lamivudine with atazanavir boosted ritonavir (ART_A and ART_B, respectively) affect in vitro PAF activity and in vivo PAF levels and metabolism. In this intent, the two ART regimens were examined in vitro against platelet aggregation induced by PAF. In addition, PAF levels and PAF metabolic enzymes were determined in HIV-1 infected volunteers before and after the initiation of antiretroviral therapy for a 12-month period. The in vitro results showed that ritonavir was the most potent inhibitor against PAF induced platelet aggregation while abacavir presented the less potent action. The in vivo results showed that tenofovir-DF/emtricitabine with atazanavir-r seems not to affect PAF levels and metabolism while abacavir/lamivudine with atazanavir-r increased bound and total PAF blood levels, PAF biosynthesis in platelets and also decreased Lp-PLA2 activity. In addition, ART_B revealed higher lyso-PAF-AT specific activity at 3rd, 6th and 9th month (p3=0.04, p6=0.04 and p9=0.03) compared to ART_A. In conclusion, there is a direct relation between in vitro and in vivo effect of antiretrovirals on PAF and abacavircontaining regimen activates PAF biosynthesis leading to elevated PAF levels.