Purpose of the studyPAF, a potent inflammatory mediator, seems to play a role in the pathogenesis of several AIDS manifestations. PAFantagonists have been studied in this context with promising results. We have previously described the in vitro interaction between HAART and PAF-induced platelet aggregation, as well as between HAART and the specific activities of the basic PAF metabolic enzymes. MethodsIn order to examine the in vivo interactions between PAF and HAART, we studied the effect of antiretroviral treatment on PAF-induced platelet aggregation and on the specific activities of the basic PAF metabolic enzymes from blood samples of HIV-patients.