title: Immunoexpression of the HLA-DR class II molecule in cells from inflamed dental pulp.
abstract: BACKGROUND
  Despite that the role of inflammatory cells in chronic inflammatory reactions of pulpal origin (CIRPOs) has been extensively studied, function of the HLA-DR+ cells (HLA-DR+ Cs) is poorly understood. The aim of this study was to quantify their number and clarify their role in these lesions.
  
  
  METHODS
  We studied 11 CIRPOs immunostained with an anti-HLA-DR class II monoclonal antibody and the number and location of the HLA-DR+ Cs quantified. CIRPOs were divided in periapical granulomas (PGs), epithelized granulomas (EGs) and periapical cysts (PCs).
  
  
  RESULTS
  HLA-DR+ Cs were observed within epithelium, inflammatory infiltrate and close to blood vessels. In PGs, they account for 19-256 cells/mm2, in EGs they were 20-494 cells/mm2 and in PCs quantification numbered 39-316 cells/mm2.
  
  
  CONCLUSIONS
  Our results suggest that HLA-DR+ Cs present antigens to lymphocytes, collaborating in initiation, regulation, development and perpetuation of CIRPOs. Also, these results suggest that these cells have an active role during initiation of epithelial proliferation in PGs and that they are partially responsible for cystic transformation from EGs to periapical cysts. They may also play an active role in bone resorption.
authors.affiliation: Laboratory of Immunology, División de Estudios de Posgrado e Investigación, Facultad de Odontología, UNAM, México, DF, México.
authors.forename: Juan Carlos
authors.initials: JC
authors.lastname: Hernández-Guerrero
authors.forename: Dolores
authors.initials: D
authors.lastname: Jiménez-Farfán
authors.forename: Andrés
authors.initials: A
authors.lastname: Castel-Rodríguez
authors.forename: Maricela
authors.initials: M
authors.lastname: Garcés-Ortiz
authors.forename: Constantino
authors.initials: C
authors.lastname: Ledesma-Montes
mesh_terms: D002908:Chronic Disease; D003782:Dental Pulp / Q000098:blood supply / Q000378:metabolism* / Q000473:pathology*; D006684:HLA-DR Antigens / Q000032:analysis* / Q000276:immunology*; D006801:Humans; D007150:Immunohistochemistry; D007249:Inflammation / Q000378:metabolism / Q000473:pathology; D008214:Lymphocytes / Q000166:cytology
chemical_list: D006684:HLA-DR Antigens