Intensity of C-reactive protein immunohistochemical staining of atherosclerotic plaque macrophages and extracellular tissue of patients with angina pectoris undergoing directional coronary atherectomy.
BACKGROUND
An elevated C-reactive protein (CRP) level plays a crucial role in cell biology of atherosclerosis and unstable plaque formation. However, direct evidence of CRP involvement in atherosclerotic plaque development and vulnerability is still limited. We hypothesized that CRP is present in the vulnerable plaques and that CRP staining intensity is stronger in vulnerable plaques compared to stable plaques.


METHODS
Directional coronary atherectomy (DCA) was performed on 58 patients with stable angina (group 1) and 40 patients with unstable angina (group 2). White blood cell (WBC) counts were measured prior to DCA. Immunohistochemical staining (IHCS) was performed to localize CRP in the atheroma. Staining intensity in macrophages and extracellular tissue was graded as: 0, no staining; 1+, < 30%; 2+, 30%-60%; 3+, > 60%.


RESULTS
The IHCS demonstrated that CRP staining - 1+ intensity in macrophages and extracellular tissue were significantly higher in group 1 than in group 2 patients (all p values < 0.0001). However, IHCS demonstrated that CRP staining a 2+ intensity in macrophages and extracellular tissue were significantly higher in group 2 than in group 1 patients (all p values < 0.0001). By multiple analysis, only stable angina was independently associated with CRP staining : 1+ intensity in both macrophages and extracellular tissue (p < 0.0001), whereas unstable angina and WBC counts were independent predictors of CRP staining > or = 2+ intensity in both macrophages and extracellular tissue (p < 0.0001).


CONCLUSIONS
CRP was frequently found in atherosclerotic plaques of patients with unstable angina. This analytical finding suggests that CRP directly mediates an inflammatory process in the atherosclerotic plaque.
Tsai
Tzu-Hsien
TH
Division of Cardiology, Chang Gung Memorial Hospital-Kaohsiung Medical Center, Chang Gung University College of Medicine, Kaohsiung, Taiwan.
Chua
Sarah
S
Yang
Cheng-Hsu
CH
Hang
Chi-Ling
CL
Hsieh
Yuan-Kai
YK
Chen
Yen-Hsun
YH
Chai
Han-Tan
HT
Yeh
Kuo-Ho
KH
Yip
Hon-Kan
HK
D000328:Adult; D000368:Aged; D000787:Angina Pectoris / Q000378:metabolism* / Q000601:surgery; D017225:Atherectomy, Coronary; D050197:Atherosclerosis / Q000378:metabolism*; D002097:C-Reactive Protein / Q000032:analysis*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008264:Macrophages / Q000737:chemistry*; D008297:Male; D008875:Middle Aged; D013194:Staining and Labeling
D002097:C-Reactive Protein