Immunoreactivity and grading of human cytomegalovirus (HCMV) antigens and inflammatory markers in human carotid atherosclerotic plaques as assayed by immunohistochemistry (IHC) staining. (A) Summary of IHC results on viral immediate early (IE), late (LA), 5-LO, CD3 and CD68 in plaques. (B-E) Panel of controls consist of omitting primary antibody (or Tris-buffered saline, TBS only) instead of IE (B), isotype control for LA (C), isotype control for IE (D), and virus-infected endothelial cells (E). (F-G) Immunoreactivity and grading of IE (F) or LA (G) in plaques. (H) Association between HCMV IgG antibodies and its IE antigens burden. Positivity was revealed by diaminobenzidine (DAB), brown products; Optical density, O.D.