850. Endothelial Progenitor Cell Production is Suppressed and Associated with Systemic Inflammation and Monocyte Activation in Older HIV-Infected Men
Session: Oral Abstract Session: HIV Co-Morbidities and Co-Infections
Thursday, October 27, 2016: 2:00 PM
Room: 275-277
Background: Endothelial progenitor cells (EPCs) repair damaged vascular endothelium and low circulating EPC levels have been associated with cardiovascular disease (CVD) burden and event rate. Treated HIV infection is associated with chronic inflammation and increased CVD risk, but the contribution of EPCs to CVD risk and the relationship between chronic inflammation and EPCs in HIV-infected (HIV+) adults remains unclear. We measured circulating EPC levels and explored associations between EPCs and biomarkers of inflammation and vascular disease among older HIV+ men on suppressive antiretroviral therapy (ART).

Methods: EPCs from 57 HIV+ men 50 years of age or older were measured by gold standard flow cytometry (methods previously optimized) using markers of cellular immaturity (CD34 or CD133) and endothelial commitment (KDR). CD34+/KDR+ EPCs are commonly reported in the literature, and CD34+/CD133+/KDR+ EPCs are rare in circulation but highly specific for endothelial lineage. Fasting circulating biomarker levels were measured by ELISA. For this pilot study, statistical significance was defined as a two-sided p<0.10.

Results:  Median age was 57 years; CD4+ T lymphocyte count 570 cells/mm3. Prevalent CVD risk factors included 16% diabetes, 28% hypertension, 53% dyslipidemia and 33% smoking. Median (interquartile range) EPC values were CD34+/KDR+ 0.1 (0.0-0.9) cells/105 peripheral blood mononuclear cells (PBMCs) and CD34+/CD133+/KDR+ 0.1 (0.0-0.9) cells/105 PBMCs. We observed a high frequency of undetectable CD34+/KDR+ (40%) and CD34+/CD133+/KDR+ (44%) EPCs. Men with undetectable EPCs were more likely to have 2 or more CVD risk factors, lower interleukin-6 levels (IL-6) and higher soluble CD163 levels (sCD163) (shown in Figure for CD34+/KDR+ EPCs).

Conclusion: In this group of older HIV+ men on suppressive ART, CD34+/KDR+ and CD34+/CD133+/KDR+ EPC levels were low and often undetectable. Undetectable EPC levels were associated with greater CVD risk factor burden, lower IL-6 levels (consistent with decreased stimulus for EPC production) and higher sCD163 levels (consistent with monocyte activation and prior associations with CVD), highlighting the complexity of factors contributing to vascular reparative capacity in this population.

Jordan Lake, MD, MSc, Department of Medicine, University of California, Los Angeles, Los Angeles, CA, Sophie Seang, MD, Hôpital Pitié-Salpêtrière, Paris, France, Theodoros Kelesidis, MD, PhD, David Geffen School of Medicine at UCLA, Los Angeles, CA and Judith Currier, MD, MSc, MPH, FIDSA, University of California, Los Angeles, Los Angeles, CA


J. Lake, None

S. Seang, None

T. Kelesidis, None

J. Currier, None

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