Carotid artery plaque uptake of 11C-PK11195 inversely correlates with circulating monocytes and classical CD14++CD16− monocytes expressing HLA-DR

• Main Authors: Enrico Ammirati, Francesco Moroni, Marco Magnoni, Elena Busnardo, Simona Di Terlizzi, Chiara Villa, Federico Sizzano, Isabella Scotti, Alessio Palini, Luca Presotto, Valentino Bettinardi, Pietro Spagnolo, Francesca Besana, Luigi Gianolli, Ornella E. Rimoldi, Paolo G. Camici
• Format: Article
• Language: English
• Published: Elsevier 2018-12-01
• Series: International Journal of Cardiology: Heart & Vasculature
• Online Access: http://www.sciencedirect.com/science/article/pii/S2352906718300459

Background: We explored the relation between blood concentrations of monocyte/lymphocyte subsets and carotid artery plaque macrophage content, measured by positron emission tomography (PET) with 11C-PK11195. Methods and results: In 9 patients with carotid plaques we performed 11C-PK11195-PET/computed tomography angiography imaging and measurement of absolute concentrations and frequencies of circulating monocytes and T-cell subsets. Plaque standardized uptake value (SUV) for 11C-PK11195 was negatively correlated with concentrations of total monocytes (r = −0.58, p = 0.05) and CD14++CD16−HLA-DR+ classical subset (r = −0.82, p = 0.005). These correlations hold true also in relation to plaque target to background ratio. No correlation was observed between plaque SUV and CD3+T lymphocytes, CD4+T lymphocytes nor with activated CD3+CD4+T cells expressing HLA-DR. Conclusions: We first demonstrated a reduction in the absolute concentration of monocytes and particularly in classical monocytes expressing HLA-DR in the presence of an increased uptake of 11C-PK11195 in carotid plaques. The present work, despite being a pilot study comprising only a small number of subjects provides new insights in the search for specific cellular biomarkers with potential diagnostic and prognostic value in patients with a known carotid plaque. Keywords: Carotid plaque, 11C-PK11195 uptake, Classical monocytes, Positron emission tomography, Atherosclerosis