Role of T‐Cell Dysfunction, Inflammation, and Coagulation in Microvascular Disease in HIV

BACKGROUND: Compared to uninfected adults, HIV‐infected adults on antiretroviral therapy are at increased risk of cardiovascular disease. Given the increase in T‐cell dysfunction, inflammation, and coagulation in HIV infection, microvascular dysfunction is thought to contribute to this excess cardiovascular risk. However, the relationships between these variables remain undefined. METHODS AND RESULTS: This was a cross‐sectional study of 358 HIV‐infected adults from the SCOPE cohort. Macrovascular endothelial function was assessed using flow‐mediated dilation of the brachial artery and microvascular function by reactive hyperemia. T‐cell phenotype was determined by flow cytometry. Plasma markers of inflammation (tumor necrosis factor‐α, interleukin‐6, high‐sensitivity C‐reactive protein, sCD14) and coagulation (fibrinogen, D‐dimer) were also measured. In all HIV+ subjects, markers of inflammation (tumor necrosis factor‐α, high‐sensitivity C‐reactive protein), coagulation (D‐dimer) and T‐cell activation (CD8+PD1+, CD4+interferon+cytomegalovirus‐specific) were associated with worse reactive hyperemia after adjusting for traditional cardiovascular risk factors and co‐infections. In treated and suppressed subjects, tumor necrosis factor‐α and CD8+PD1+ cells remained associated with worse reactive hyperemia after adjustment. Compared to the untreated subjects, CD8+PD1+ cells were increased in the virally suppressed group. Reactive hyperemia was predictive of flow‐mediated dilation. CONCLUSIONS: CD8+PD1+ cells and tumor necrosis factor‐α were associated with microvascular dysfunction in all HIV+ subjects and the treated and suppressed group. Additionally, D‐dimer, high‐sensitivity C‐reactive protein, sCD‐14, and interleukin‐6 were associated with microvascular dysfunction in all HIV+ subjects. Although T‐cell dysfunction, inflammation, and microvascular dysfunction are thought to play a role in cardiovascular disease in HIV, this study is the first to look at which T‐cell and inflammatory markers are associated with microvascular dysfunction in HIV‐infected individuals.