title: Quantification of Various Inflammatory Cells in Advanced Atherosclerotic Plaques.
abstract: BACKGROUND
  Atherosclerosis, the pathological basis of coronary artery disease is being extensively studied as understanding of the complex processes involved in the formation and progression that can provide an insight into prevention and treatment of the same. This is an autopsy study to identify and quantify various inflammatory cells in advanced atherosclerotic plaques.
  
  
  OBJECTIVE
  This study aims at identifying and categorizing the various inflammatory cells present in advanced atherosclerotic plaques, noting their distribution in the plaque, quantifying them using histomorphometry and comparing them across plaques of different AHA types.
  
  
  METHODS
  Post-mortem angiogram was performed on 3 heart specimens obtained at autopsy of random Road Traffic Accident (RTA) cases which revealed evidence of coronary artery disease. End-arterectomy was done and the arteries with atherosclerotic plaques were cut into serial sections and made into tissue blocks. Sections from these blocks were stained with H & E stain and the plaques were classified based on AHA classification. 50 advanced atherosclerotic plaques of AHA Type IV and V were chosen for this study and were screened for inflammatory cells, first with H & E stain and then with different immunohistochemical stains for T-lymphocytes, B-lymphocytes and neutrophils. The T-lymphocytes thus identified was further sub-typed into CD4+ and CD8+ cells again using IHC markers and the percentage area of each was measured using histomorphometry. Then, these values were compared between AHA Type IV and AHA Type V lesions.
  
  
  RESULTS
  It was found that the inflammatory cells found in advanced atherosclerotic plaques were predominantly T-lymphocytes as evidenced by their CD3 positivity and they were found to be distributed mainly around the shoulder region and fibrous cap of the plaque. When categorized further, it was found that CD8+ T-cells were always more than CD4+ T-cells in advanced lesions. Meloperoxidase stain for neutrophils was negative in all the plaques examined. The difference in the amount of inflammatory cells between AHA type IV and Type V was not statistically significant.
  
  
  CONCLUSIONS
  The study of the amount of inflammatory cells in atherosclerotic plaques and understanding their role in the pathophysiology of advanced plaques may have therapeutic implications.
authors.affiliation: Assistant Professor, Department of Pathology, A.C.S Medical College , Chennai, India .
authors.forename: Veronica Soundra Veena
authors.initials: VS
authors.lastname: Paul
authors.affiliation: Associate Professor, Department of Community Medicine, A.C.S Medical College , Chennai, India .
authors.forename: Christina Mary Priya
authors.initials: CM
authors.lastname: Paul
authors.affiliation: Senior Consultant and Head of the Department, Department of Pathology, The Madras Medical Mission Hospital , Chennai, India .
authors.forename: Sarah
authors.initials: S
authors.lastname: Kuruvilla
keywords: End-arterectomy; Histomorphometric study; Immunohistochemistry of advanced plaques; Inflammation in atherosclerosis