Widespread vascular production of C-reactive protein (CRP) and a relationship between serum CRP, plaque CRP and intimal hypertrophy

Objectives: Evidence of local vascular production and a relationship between serum hsCRP levels and tissue expression of CRP in subjects with vascular disease would support a direct role for CRP in atherosclerosis. Methods and results: Vascular tissue from subjects undergoing coronary artery bypass grafting surgery (CABGS) (n = 28) and carotid endarterectomy (CEA) (n = 25) were studied. Histological samples were assessed for intima-media ratio (IMR) and CRP by immunohistochemistry. CRP mRNA was quantified by real-time polymerase chain reaction. CRP mRNA was seen in all plaques, non-atherosclerotic artery and atrium but no difference in mRNA expression was seen between plaque and non-atherosclerotic tissue. Serum hsCRP correlated with IMR (r = 0.64, p = 0.001) in non-atherosclerotic arteries and with plaque CRP staining (r = 0.57, p = 0.009) independent of age, BMI, lipids, diabetes and blood pressure. In a separate patient series, serum hsCRP was measured in aortic and coronary sinus blood from subjects undergoing CABGS or angiography (n = 54). There was a coronary circulation hsCRP gradient ([mean ± S.E.M.] aortic CRP 4.3 mg/l ± 0.8 versus coronary sinus 5.8 ± 1.2 mg/l, p < 0.05). Conclusions: Widespread vascular CRP mRNA expression, a correlation between serum hsCRP, intimal hypertrophy and plaque CRP, and a coronary hsCRP gradient suggest vascular secretion may contribute to serum CRP levels.