title: Perivascular Adipose Tissue Inflammation and Coronary Artery Disease: An Autopsy Study Protocol.
abstract: BACKGROUND
  Perivascular adipose tissue (PAT) inflammation may have a role in coronary artery disease (CAD) pathophysiology. However, most evidence has come from samples obtained during surgical procedures that may imply in some limitations. Moreover, the role of B lymphocytes and inflammation in PAT that is adjacent to unstable atheroma plaques has not been investigated in humans using morphometric measurements.
  
  
  OBJECTIVE
  The objective of this study is to investigate the inflammation in PAT, subcutaneous, and perirenal adipose tissues (SAT and PrAT) among chronic CAD, acute CAD, and control groups in an autopsy study.
  
  
  METHODS
  Heart, SAT, and PrAT samples are collected from autopsied subjects in a general autopsy service, with the written informed consent of the next-of-kin (NOK). Sociodemographic and clinical data are obtained from a semistructure interview with the NOK. Coronary arteries are dissected and PAT are removed. Sections with the greatest arterial obstruction or unstable plaques, and the local with absence of atherosclerosis in all coronary arteries are sampled. PAT are represented adjacent to these fragments. Adipose tissues are fixed in 4% buffered paraformaldehyde solution and analyzed immunohistochemically for macrophages (CD68), macrophage polarization (CD11c for proinflammatory and CD206 for anti-inflammatory), B lymphocytes (CD20), and T lymphocytes (CD3). Slides will be scanned, and inflammatory cells will be quantified in 20 random fields. Participants will be categorized in CAD groups, after morphometric measurement of arterial obstruction and plaque composition analysis in accordance with American Heart Association classification. Three study groups will be investigated: acute CAD (at least one unstable plaque); chronic CAD (≥50% arterial obstruction); and controls (<50% arterial obstruction). Inflammatory cells in PAT, SAT, and PrAT will be counted and compared between groups using multivariate linear regression, adjusted for age, body mass index, hypertension, diabetes, alcohol use, and smoking.
  
  
  RESULTS
  We present the methods of our study that was developed from 2 pilots. Currently, data collection and tissue processing are ongoing. Data collection, histology and immunochemistry procedures, and quantification of all inflammatory cells are expected to be concluded within 1 year.
  
  
  CONCLUSIONS
  This study will contribute for the understanding of the mechanisms of CAD pathophysiology because it will help to clarify the role of inflammation both in chronic and acute CAD.
authors.affiliation: Laboratory of Cardiovascular Pathology, Department of Pathology - LIM22, University of Sao Paulo Medical School, Sao Paulo, Brazil.|Physiopathology in Aging Lab/Brazilian Aging Brain Study Group - LIM22, University of Sao Paulo Medical School, Sao Paulo, Brazil.
authors.forename: Daniela Souza
authors.identifier: http://orcid.org/0000-0001-6297-751X
authors.initials: DS
authors.lastname: Farias-Itao
authors.affiliation: Laboratory of Cardiovascular Pathology, Department of Pathology - LIM22, University of Sao Paulo Medical School, Sao Paulo, Brazil.|Physiopathology in Aging Lab/Brazilian Aging Brain Study Group - LIM22, University of Sao Paulo Medical School, Sao Paulo, Brazil.
authors.forename: Carlos Augusto
authors.identifier: http://orcid.org/0000-0001-6608-2473
authors.initials: CA
authors.lastname: Pasqualucci
authors.affiliation: Laboratory of Cardiovascular Pathology, Department of Pathology - LIM22, University of Sao Paulo Medical School, Sao Paulo, Brazil.|Physiopathology in Aging Lab/Brazilian Aging Brain Study Group - LIM22, University of Sao Paulo Medical School, Sao Paulo, Brazil.
authors.forename: Aline
authors.identifier: http://orcid.org/0000-0001-6249-1157
authors.initials: A
authors.lastname: Nishizawa
authors.affiliation: Department of Pathology, University of Sao Paulo Medical School, Sao Paulo, Brazil.
authors.forename: Luiz Fernando Ferraz
authors.identifier: http://orcid.org/0000-0002-0181-6357
authors.initials: LF
authors.lastname: Silva
authors.affiliation: Laboratory of Cardiovascular Pathology, Department of Pathology - LIM22, University of Sao Paulo Medical School, Sao Paulo, Brazil.
authors.forename: Fernanda Marinho
authors.identifier: http://orcid.org/0000-0001-7149-5280
authors.initials: FM
authors.lastname: Campos
authors.affiliation: Laboratory of Cardiovascular Pathology, Department of Pathology - LIM22, University of Sao Paulo Medical School, Sao Paulo, Brazil.|Physiopathology in Aging Lab/Brazilian Aging Brain Study Group - LIM22, University of Sao Paulo Medical School, Sao Paulo, Brazil.
authors.forename: Karen Cristina Souza da
authors.identifier: http://orcid.org/0000-0002-7394-3216
authors.initials: KC
authors.lastname: Silva
authors.affiliation: Physiopathology in Aging Lab/Brazilian Aging Brain Study Group - LIM22, University of Sao Paulo Medical School, Sao Paulo, Brazil.|Discipline of Geriatrics, University of Sao Paulo Medical School, Sao Paulo, Brazil.
authors.forename: Renata Elaine Paraizo
authors.identifier: http://orcid.org/0000-0002-5878-398X
authors.initials: RE
authors.lastname: Leite
authors.affiliation: Physiopathology in Aging Lab/Brazilian Aging Brain Study Group - LIM22, University of Sao Paulo Medical School, Sao Paulo, Brazil.|Memory and Aging Center, Department of Neurology, University of California, San Francisco, CA, United States.
authors.forename: Lea Tenenholz
authors.identifier: http://orcid.org/0000-0002-6809-0618
authors.initials: LT
authors.lastname: Grinberg
authors.affiliation: Physiopathology in Aging Lab/Brazilian Aging Brain Study Group - LIM22, University of Sao Paulo Medical School, Sao Paulo, Brazil.|Medical-Surgical Nursing Department, University of Sao Paulo School of Nursing, Sao Paulo, Brazil.
authors.forename: Renata Eloah Lucena
authors.identifier: http://orcid.org/0000-0002-6159-5787
authors.initials: RE
authors.lastname: Ferretti-Rebustini
authors.affiliation: Physiopathology in Aging Lab/Brazilian Aging Brain Study Group - LIM22, University of Sao Paulo Medical School, Sao Paulo, Brazil.|Discipline of Geriatrics, University of Sao Paulo Medical School, Sao Paulo, Brazil.
authors.forename: Wilson
authors.identifier: http://orcid.org/0000-0003-2290-4492
authors.initials: W
authors.lastname: Jacob Filho
authors.affiliation: Laboratory of Cardiovascular Pathology, Department of Pathology - LIM22, University of Sao Paulo Medical School, Sao Paulo, Brazil.|Physiopathology in Aging Lab/Brazilian Aging Brain Study Group - LIM22, University of Sao Paulo Medical School, Sao Paulo, Brazil.|Discipline of Geriatrics, University of Sao Paulo Medical School, Sao Paulo, Brazil.
authors.forename: Claudia Kimie
authors.identifier: http://orcid.org/0000-0002-5942-4778
authors.initials: CK
authors.lastname: Suemoto
keywords: B lymphocytes; T lymphocytes; adipose tissue; atherosclerosis; coronary artery disease; inflammation; macrophages