PB1203 - The influence of human immunodeficiency virus infection and antiretroviral therapy on plasma clot properties in a group of Black South African women

Background: Human immunodeficiency virus (HIV) and antiretroviral treatment (ART) are both associated with increased cardiovascular disease (CVD) risk. Altered plasma clot properties could be a potential mechanism. Currently, very little evidence on the effects of HIV and ART on clot properties is available.

Aims: To determine the association of HIV status and ART with plasma clot properties in 21 HIV-infected and 12 (age, body mass index, and contraceptive use matched) HIV-uninfected African women.

Methods: Before commencement, ethics approval was obtained, and volunteers signed informed consent. At baseline, newly diagnosed, treatment-naive HIV-infected women were recruited. At the 5-year follow-up, ten women were using ART while 11 remained treatment-naive. Differences in fibrinogen concentration (Clauss); fibrinogen gamma prime (ELISA); clot formation, structure and lysis (turbidimetry); structural properties (permeability and scanning electron microscopy) and mechanical properties (rheometry) were investigated at baseline (Mann-Whitney U test), and prospectively within (Wilcoxon matched pair) and between groups (Linear mixed methods).

Results: There was no significant difference in the measured clot properties at baseline between newly HIV-infected women and matched controls, except for a tendency of longer lysis times in the HIV-infected individuals (Table 1). The rate of clot formation increased over time in the control group, while not in the HIV-infected groups. Increased maximum absorbance and fibre diameter were observed in all three groups, while permeability increased only in the treated HIV-infected participants. Clot lysis time increased in the treated and control groups, but not in the untreated group. In terms of mechanical properties, both G’ and G” increased in the HIV untreated and control groups, while no changes were observed for the treated group (Table 2).

Conclusion(s): In this study population, HIV infection and ART altered changes in clot properties over time compared to matched uninfected African women. ART use specifically, altered clot mechanical properties and increased clot permeability, but prolonged fibrinolysis.