CRP immunopositivity with the corresponding histopathologic findings.

(A–D) Aorta specimen from a patient with abdominal aortic aneurysm and mildly elevated serum CRP (0.28 mg/dL). The site of strong and linear CRP (C) and mCRP (D) immunopositivity was found in the interface (arrow) between atherosclerotic plaque (asterisk) and the thinned aneurysmal wall (between the two arrowheads). This immunopositive lesion was correlated with the area of the diminished elastic lamella of the eroded media (B). Atheroma was diffusely immunopositive for both CRP and mCRP. (A, H&E, B, elastic staining, C, anti-CRP antibody, D, anti-mCRP antibody, × 40). (E–H) Aorta specimen from a patient with ascending aortic dissection with mildly elevated serum CRP (0.74 mg/dL). CRP and mCRP were faintly and nonspecifically stained in the smooth muscle cell of tunica media. CRP was not stained at the boundary of the damaged and the torn aortic wall. (E, H&E, F, elastic staining, G, anti-CRP antibody, H, anti-mCRP antibody, × 40).