© 2003 by European Society of Cardiology
Copyright © 2003, European Society of Cardiology
Presence of bone-marrow- and neural-crest-derived cells in intimal hyperplasia at the time of clinical in-stent restenosis
Department of Cardiology, Heart Center University of Bonn, Sigmund-Freud-Str. 25, 53105 Bonn, Germany
*Corresponding author. Tel.: +49-228-287-6670; fax: +49-228-287-4983. Email address: gerhard.bauriedel{at}ukb.uni-bonn.de
Objective: Intralesional data of coronary target lesions following stent implantation are infrequent. In addition, there is ongoing controversy on the origin of neointimal cells. In this respect, several lines of evidence revealed bone-marrow-derived endothelial progenitor and dendritic cells (DCs) as well as neural-crest-derived cells (NCCs) to contribute to atherosclerosis. Therefore, the objective of the present study was to assess cellularity, cell type and origin of neointimal cells in in-stent restenosis (ISR). Methods: Atherectomy specimens from 17 patients with coronary in-stent restenosis (n = 10; time post-stenting 5±3 months) and with peripheral in-stent restenosis (n = 7; 7±3 months) versus those from 10 patients with primary lesions were immunohistochemically examined for the presence of the determinants CD34, AC133, S100, glial fibrillary acidic protein (GFAP), neuron-specific enolase (NSE), nerve growth factor receptor (NGFR) and 
-smooth muscle actin followed by computer-assisted morphometry. Results: In-stent restenosis probes consistently demonstrated homogeneous hypercellularity (942±318 cells/mm2) compared to de novo lesions (347±120 cells/mm2, P<0.001). -smooth muscle actin positive cells occupied 67% of intimal cells in in-stent restenosis. As a key finding, expression of endothelial progenitor cells (CD34: 7.1±2.5% positive/total cells vs. 0.6±0.7%, P<0.001; AC133: 7.0±3.4% vs. 1.0±0.7%, P<0.001), dendritic cells (S100: 9.8±5.6% vs. 1.4±1.1%, P<0.001) and neural-crest-derived cells (GFAP: 7.9±2.4% vs. 3.1±1.0%; NSE: 4.4±2.6% vs. 1.3±1.6%; NGFR: 4.2±2.5% vs. 1.1±0.7%; each P<0.001) was significantly increased in in-stent restenosis compared to primary lesions. Conclusions: Bone-marrow- and neural-crest-derived cells, the most dendritic cells, are consistently present in in-stent restenosis, whereas -smooth muscle actin positive cells constitute the largest intimal cell pool. Our data suggest the recruitment of primarily extravascular cells within neointima formation in human in-stent restenosis.
KEYWORDS Atherosclerosis; Histo(patho)logy; Restenosis; Stem cells; Stents