Abstract 18348: Total Mast Cell Numbers in Human Carotid Atherosclerotic Plaques and Tryptase Plasma Levels are Predictive for Future Cardiovascular Events
Mast cells (MCs) are inflammatory cells known to contribute to the pathogenesis of atherosclerotic disease. Experimental studies have revealed that MCs might be involved in the progression of atherosclerosis by inducing intraplaque neovascularization.
OBJECTIVE: This study was designed to assess total MC numbers and relate the score to neovascularization in human atherosclerotic plaques. In addition we related the presence of plaque MCs with the occurrence of adverse cardiovascular events during follow-up.
METHODS AND RESULTS: In the current study atherosclerotic plaques of 270 patients suffering from carotid artery stenosis, were stained for the presence of MCs (MC tryptase), macrophages (CD68), neutrophils (CD66) and microvessels (CD34). Furthermore, during a follow-up of 3 years, cardiovascular related endpoints were assessed in all patients. Counting of mast cells revealed a surprising high number of MCs that were present in plaques (165 ± 10 MC per plaque). We equally divided the patient cohort into a group with low (n=126) and high (n=127) total MC numbers. High MC numbers were associated with high microvessel density 6,0 [4,3-9,0] versus 10,7 [6,5-14,2] vessels per hotspot (P<0.001). Patients with high plaque MC numbers showed significantly more cardiovascular events during follow up (35 [28%] versus 54 [43%] events (P<0.05)). Macrophage and neutrophil presence did not show this association with the occurrence of cardiovascular events. In addition, in 80 patients (1:1 event versus no event) MC tryptase and chymase have been measured in plasma. Patients with high plasma tryptase showed significantly more cardiovascular events (11 [28%] versus 24 [60%] events (P<0.01)). Plasma chymase levels did not show predictive value in our cohort.
CONCLUSIONS: MCs are highly prevalent in carotid atherosclerotic lesions and associated with plaque neovessel density. Total intraplaque MC numbers and MC plasma tryptase levels are predictive for future cardiovascular events. These data support the view that MCs could play an important role in progression of atherosclerotic disease.
- © 2012 by American Heart Association, Inc.