title: Distribution of mast cells and macrophages and expression of interleukin-6 in periapical cysts.
abstract: BACKGROUND
  Mast cells and macrophages are important components of the inflammatory infiltrate found in inflammatory periapical diseases. Several cytokines participate in the mechanisms of inflammation, tissue repair, and bone resorption associated with periapical cysts. The aim of the present study was to evaluate the distribution of mast cells and macrophages and the expression of interleukin-6 (IL-6) in periapical cysts.
  
  
  METHODS
  Thirty periapical cysts were selected for the study, and clinical, demographic, and gross information from the cases was obtained from the laboratory records. Five-micrometer sections stained with hematoxylin-eosin were reviewed for analysis of the microscopic features of the cysts, and 3-μm sections on silanized slides were used for immunohistochemical reactions with anti-tryptase, anti-CD68, and anti-IL-6.
  
  
  RESULTS
  There was no statistically significant difference in the mean number of mast cells and macrophages when comparing superficial and deep regions of the fibrous capsule of the cysts. Mean number of mast cells on the superficial region of the fibrous capsule was higher in cysts showing intense superficial inflammation and exocytosis. Macrophages were more commonly found in areas showing IL-6 expression, and IL-6 was less expressed in deep regions of the fibrous capsule in cysts showing greater gross volume.
  
  
  CONCLUSIONS
  The results reinforced the participation of mast cells and macrophages in the pathogenesis of periapical cysts and suggested that IL-6 is not the major bone resorption mediator in larger periapical cysts.
authors: Post Graduation Program in Dentistry, Estácio de Sá University, Rio de Janeiro, Brazil.
authors: Igor Vieira
authors: IV
authors: Bracks
authors: Post Graduation Program in Dentistry, Estácio de Sá University, Rio de Janeiro, Brazil.
authors: Luciana
authors: L
authors: Armada
authors: Post Graduation Program in Dentistry, Estácio de Sá University, Rio de Janeiro, Brazil.
authors: Lúcio Souza
authors: LS
authors: Gonçalves
authors: Post Graduation Program in Dentistry, Estácio de Sá University, Rio de Janeiro, Brazil. Electronic address: ramoafop@yahoo.com.
authors: Fábio Ramôa
authors: FR
authors: Pires
mesh_terms: D000328:Adult; D000368:Aged; D015703:Antigens, CD / Q000032:analysis; D015214:Antigens, Differentiation, Myelomonocytic / Q000032:analysis; D002452:Cell Count; D002784:Cholesterol / Q000032:analysis; D003238:Connective Tissue / Q000276:immunology / Q000473:pathology; D004848:Epithelium / Q000276:immunology / Q000473:pathology; D005089:Exocytosis / Q000276:immunology; D005260:Female; D006801:Humans; D015850:Interleukin-6 / Q000032:analysis*; D008264:Macrophages / Q000276:immunology* / Q000473:pathology; D008297:Male; D008407:Mast Cells / Q000276:immunology* / Q000473:pathology; D008875:Middle Aged; D011842:Radicular Cyst / Q000276:immunology* / Q000473:pathology; D053802:Tryptases / Q000032:analysis; D055815:Young Adult; D000097382:CD68 Molecule
chemical_list: D015703:Antigens, CD; D015214:Antigens, Differentiation, Myelomonocytic; D002784:Cholesterol; D015850:Interleukin-6; D053802:Tryptases; C067980:CD68 antigen, human; D000097382:CD68 Molecule; C508600:IL6 protein, human
keywords: Interleukin 6; macrophage; mast cell; periapical cyst