Plasma levels of granzyme B are increased in patients with lipid-rich carotid plaques as determined by echogenicity

Abstract Increased echolucency of carotid plaques is associated with an increased risk of ischemic stroke. Inflammation and apoptosis of vascular smooth muscle cells in the arterial wall are involved in the atherosclerotic process and destabilization of the plaque. Granzyme B (GrB) is a key mediator of T cell-mediated cytotoxicity, and we therefore hypothesized that this protease could distinguish echolucent from other plaques. Ultrasound-determined echolucency of atherosclerotic plaques was assessed prior to carotid endarterectomy/angioplasty in 57 consecutively recruited patients with high-grade internal carotid stenosis. Plasma levels of GrB were measured by enzyme immunoassay prior to surgery. Patients with carotid atherosclerosis had significantly higher plasma levels of GrB compared to healthy controls ( n  = 16) ( p n  = 16) and those with echogenic/heterogeneous ( n  = 41) plaques, the echolucent group had markedly raised plasma levels of GrB ( p