Evaluation of 68Ga-Glutamate Carboxypeptidase II Ligand Positron Emission Tomography for Clinical Molecular Imaging of Atherosclerotic Plaque Neovascularization

TY - JOUR

T1 - Evaluation of 68Ga-Glutamate Carboxypeptidase II Ligand Positron Emission Tomography for Clinical Molecular Imaging of Atherosclerotic Plaque Neovascularization

AU - Derlin, Thorsten

AU - Thiele, Johannes

AU - Weiberg, Desiree

AU - Thackeray, James T

AU - Püschel, Klaus

AU - Wester, Hans-Jürgen

AU - Aguirre Dávila, Lukas

AU - Larena-Avellaneda, Axel

AU - Daum, Günter

AU - Bengel, Frank M

AU - Schumacher, Udo

N1 - © 2016 American Heart Association, Inc.

PY - 2016/11

Y1 - 2016/11

N2 - OBJECTIVE: Intraplaque neovascularization contributes to the progression and rupture of atherosclerotic lesions. Glutamate carboxypeptidase II (GCPII) is strongly expressed by endothelial cells of tumor neovasculature and plays a major role in hypoxia-induced neovascularization in rodent models of benign diseases. We hypothesized that GCPII expression may play a role in intraplaque neovascularization and may represent a target for imaging of atherosclerotic lesions. The aim of this study was to determine frequency, pattern, and clinical correlates of vessel wall uptake of a (68)Ga-GCPII ligand for positron emission tomographic imaging.APPROACH AND RESULTS: Data from 150 patients undergoing (68)Ga-GCPII ligand positron emission tomography were evaluated. Tracer uptake in various arterial segments was analyzed and was compared with calcified plaque burden, cardiovascular risk factors, and immunohistochemistry of carotid specimens. Focal arterial uptake of (68)Ga-GCPII ligand was identified at 5776 sites in 99.3% of patients. The prevalence of uptake sites was highest in the thoracic aorta; 18.4% of lesions with tracer uptake were colocalized with calcified plaque. High injected dose (P=0.0005) and obesity (P=0.007) were significantly associated with (68)Ga-GCPII ligand accumulation, but other cardiovascular risk factors showed no association. The number of (68)Ga-GCPII ligand uptake sites was significantly associated with overweight condition (P=0.0154). Immunohistochemistry did not show GCPII expression. Autoradiographic blocking studies indicated nonspecific tracer binding.CONCLUSIONS: (68)Ga-GCPII ligand positron emission tomography does not identify vascular lesions associated with atherosclerotic risk. Foci of tracer accumulation are likely caused by nonspecific tracer binding and are in part noise-related. Taken together, GCPII may not be a priority target for imaging of atherosclerotic lesions.

AB - OBJECTIVE: Intraplaque neovascularization contributes to the progression and rupture of atherosclerotic lesions. Glutamate carboxypeptidase II (GCPII) is strongly expressed by endothelial cells of tumor neovasculature and plays a major role in hypoxia-induced neovascularization in rodent models of benign diseases. We hypothesized that GCPII expression may play a role in intraplaque neovascularization and may represent a target for imaging of atherosclerotic lesions. The aim of this study was to determine frequency, pattern, and clinical correlates of vessel wall uptake of a (68)Ga-GCPII ligand for positron emission tomographic imaging.APPROACH AND RESULTS: Data from 150 patients undergoing (68)Ga-GCPII ligand positron emission tomography were evaluated. Tracer uptake in various arterial segments was analyzed and was compared with calcified plaque burden, cardiovascular risk factors, and immunohistochemistry of carotid specimens. Focal arterial uptake of (68)Ga-GCPII ligand was identified at 5776 sites in 99.3% of patients. The prevalence of uptake sites was highest in the thoracic aorta; 18.4% of lesions with tracer uptake were colocalized with calcified plaque. High injected dose (P=0.0005) and obesity (P=0.007) were significantly associated with (68)Ga-GCPII ligand accumulation, but other cardiovascular risk factors showed no association. The number of (68)Ga-GCPII ligand uptake sites was significantly associated with overweight condition (P=0.0154). Immunohistochemistry did not show GCPII expression. Autoradiographic blocking studies indicated nonspecific tracer binding.CONCLUSIONS: (68)Ga-GCPII ligand positron emission tomography does not identify vascular lesions associated with atherosclerotic risk. Foci of tracer accumulation are likely caused by nonspecific tracer binding and are in part noise-related. Taken together, GCPII may not be a priority target for imaging of atherosclerotic lesions.

U2 - 10.1161/ATVBAHA.116.307701

DO - 10.1161/ATVBAHA.116.307701

M3 - SCORING: Journal article

C2 - 27609368

VL - 36

SP - 2213

EP - 2219

JO - ARTERIOSCL THROM VAS

JF - ARTERIOSCL THROM VAS

SN - 1079-5642

IS - 11

ER -