Increased CD34+/KDR+ cells are not associated with carotid artery intima-media thickness progression in chronic HIV-positive subjects.
BACKGROUND
Endothelial progenitor cells (EPCs) are involved in the endothelium repair. Low circulating EPC levels are predictive of cardiovascular events in HIV-negative subjects. The impact of HIV infection on EPCs, and the role of EPCs in HIV-associated cardiovascular disease, is not known. We hypothesized that circulating EPCs would be inversely associated with carotid artery intima-media thickness (c-IMT) changes in HIV-infected subjects.


METHODS
EPCs (CD34(+)/KDR(+), CD133(+)/KDR(+) and CD34(+)/CD133(+)/KDR(+)) were defined retrospectively by flow cytometry in cryopreserved peripheral blood mononuclear cells collected longitudinally from 66 chronic HIV-infected subjects and cross-sectionally from 50 at-risk HIV-negative subjects. The HIV-infected subjects participated in the Study of the Consequences of the Protease Inhibitor Era (SCOPE) cohort, were receiving antiretroviral therapy (59/66) and had two sequential measurements of c-IMT 1 year apart. Two distinct groups of HIV-infected subjects were identified a priori: rapid c-IMT progressors (subjects with rapid c-IMT progression, n=13, Δc-IMT>0.2 mm) and slow c-IMT progressors (subjects with slow or no c-IMT progression, n=53, Δc-IMT<0.2 mm).


RESULTS
Although cryopreservation reduced sensitivity of detection, EPC frequency in HIV-infected subjects was still significantly higher compared to at-risk HIV-negative subjects (CD34(+)/KDR(+); P=0.01) and correlated positively with CD4(+) T-cell count (CD34(+)/KDR(+), r=0.27; P=0.03). No association was found between the change of EPC frequencies over time (ΔEPC) and Δc-IMT or between EPC frequencies and c-IMT or Δc-IMT.


CONCLUSIONS
The lack of an association between EPCs and c-IMT in our cohort does not support HIV-associated reductions in EPC frequency as a cause of accelerated atherosclerosis.
The Wistar Institute, Philadelphia, PA, USA.
Emmanouil
E
Papasavvas
Priscilla
P
Hsue
Griffin
G
Reynolds
Maxwell
M
Pistilli
Aidan
A
Hancock
Jeffrey N
JN
Martin
Steven G
SG
Deeks
Luis J
LJ
Montaner
D018952:Antigens, CD34 / Q000378:metabolism*; D050197:Atherosclerosis / Q000503:physiopathology*; D002339:Carotid Arteries / Q000000981:diagnostic imaging; D059168:Carotid Intima-Media Thickness; D002908:Chronic Disease; D018450:Disease Progression; D042783:Endothelial Cells / Q000166:cytology / Q000378:metabolism*; D004730:Endothelium, Vascular / Q000503:physiopathology; D005260:Female; D005434:Flow Cytometry; D015658:HIV Infections / Q000150:complications* / Q000473:pathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D013234:Stem Cells / Q000166:cytology / Q000378:metabolism*; D017539:Tunica Intima / Q000000981:diagnostic imaging; D017540:Tunica Media / Q000000981:diagnostic imaging
D018952:Antigens, CD34