Placenta growth factor expression in human atherosclerotic carotid plaques is related to plaque destabilization

Background and purpose Placenta growth factor (PlGF) mediates angiogenesis and inflammation, but its role in human atherosclerosis is unknown. This study was designed to test the hypothesis that PlGF-expression in human atherosclerotic carotid plaques is related to inflammation, vascularization and clinical plaque instability. Methods The expression of PlGF, C-reactive protein (CRP) and CD40L was analyzed with Western blots in carotid plaques of 60 patients. Cellular infiltration (CD68, CD3) and vascularization (von-Willebrand-factor) was assessed by immunohistochemistry. Results Symptomatic patients showed higher levels of PlGF than asymptomatic patients (115.4 ± 8.2 versus 83.6 ± 10.5 densitometric units (DU), p < 0.05) and higher grading for inflammatory cells and microvessels (CD3: 2.3 ± 0.1 versus 0.6 ± 0.1, p < 0.001, CD68: 2.4 ± 0.1 versus 0.8 ± 0.1, p < 0.001, microvessels: 2.3 ± 0.1 versus 1.5 ± 0.1, p < 0.01). PlGF-expression showed a positive correlation to the expression of CRP (r = 0.5, p < 0.001) and CD40L (r = 0.4, p < 0.01). Conclusions PlGF-expression within human atherosclerotic lesions is associated with plaque inflammation and microvascular density, suggesting a role for PlGF in plaque destabilization and, thus, in clinical manifestation of the disease.