title: Analysis of immune cell populations in atrial myocardium of patients with atrial fibrillation or sinus rhythm.
abstract: BACKGROUND
  Atrial fibrillation (AF) is the most common arrhythmia and despite obvious clinical importance remains its pathogenesis only partially explained. A relation between inflammation and AF has been suggested by findings of increased inflammatory markers in AF patients.
  
  
  OBJECTIVE
  The goal of this study was to characterize morphologically and functionally CD45-positive inflammatory cell populations in atrial myocardium of patients with AF as compared to sinus rhythm (SR).
  
  
  METHODS
  We examined 46 subjects (19 with AF, and 27 in SR) undergoing coronary bypass or valve surgery. Peroperative bioptic samples of the left and the right atrial tissue were examined using immunohistochemistry.
  
  
  RESULTS
  The number of CD3+ T-lymphocytes and CD68-KP1+ cells were elevated in the left atrial myocardium of patients with AF compared to those in SR. Immune cell infiltration of LA was related to the rhythm, but not to age, body size, LA size, mitral regurgitation grade, type of surgery, systemic markers of inflammation or presence of diabetes or hypertension. Most of CD68-KP1+ cells corresponded to dendritic cell population based on their morphology and immunoreactivity for DC-SIGN. The numbers of mast cells and CD20+ B-lymphocytes did not differ between AF and SR patients. No foci of inflammation were detected in any sample.
  
  
  CONCLUSIONS
  An immunohistochemical analysis of samples from patients undergoing open heart surgery showed moderate and site-specific increase of inflammatory cells in the atrial myocardium of patients with AF compared to those in SR, with prevailing population of monocyte-macrophage lineage. These cells and their cytokine products may play a role in atrial remodeling and AF persistence.
authors.affiliation: Institute of Histology and Embryology, The First Faculty of Medicine, Charles University, Prague, Czech Republic.
authors.forename: Natalia
authors.initials: N
authors.lastname: Smorodinova
authors.affiliation: Institute for Clinical and Experimental Medicine-IKEM, Department of Cardiology, Prague, Czech Republic.
authors.forename: Martin
authors.initials: M
authors.lastname: Bláha
authors.affiliation: Institute for Clinical and Experimental Medicine-IKEM, Department of Cardiology, Prague, Czech Republic.
authors.forename: Vojtěch
authors.initials: V
authors.lastname: Melenovský
authors.affiliation: Institute of Histology and Embryology, The First Faculty of Medicine, Charles University, Prague, Czech Republic.
authors.forename: Karolína
authors.initials: K
authors.lastname: Rozsívalová
authors.affiliation: Institute of Histology and Embryology, The First Faculty of Medicine, Charles University, Prague, Czech Republic.
authors.forename: Jaromír
authors.initials: J
authors.lastname: Přidal
authors.affiliation: Institute of Histology and Embryology, The First Faculty of Medicine, Charles University, Prague, Czech Republic.
authors.forename: Mária
authors.initials: M
authors.lastname: Ďurišová
authors.affiliation: Institute for Clinical and Experimental Medicine-IKEM, Department of Cardiovascular Surgery, Prague, Czech Republic.
authors.forename: Jan
authors.initials: J
authors.lastname: Pirk
authors.affiliation: Institute for Clinical and Experimental Medicine-IKEM, Department of Cardiology, Prague, Czech Republic.
authors.forename: Josef
authors.initials: J
authors.lastname: Kautzner
authors.affiliation: Institute of Histology and Embryology, The First Faculty of Medicine, Charles University, Prague, Czech Republic.
authors.forename: Tomáš
authors.initials: T
authors.lastname: Kučera
mesh_terms: D000368:Aged; D001146:Arrhythmia, Sinus / Q000276:immunology / Q000473:pathology* / Q000503:physiopathology; D001281:Atrial Fibrillation / Q000276:immunology / Q000473:pathology* / Q000503:physiopathology; D001402:B-Lymphocytes / Q000276:immunology / Q000473:pathology; D002452:Cell Count; D048430:Cell Shape; D005260:Female; D006325:Heart Atria / Q000276:immunology / Q000473:pathology* / Q000503:physiopathology; D006801:Humans; D008297:Male; D008407:Mast Cells / Q000276:immunology / Q000473:pathology; D008875:Middle Aged; D009206:Myocardium / Q000276:immunology / Q000473:pathology*; D013601:T-Lymphocytes / Q000276:immunology / Q000473:pathology*