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.