title: Specific infiltration pattern of FOXP3+ regulatory T cells in chronic histiocytic intervillositis of unknown etiology.
abstract: BACKGROUND
  Chronic histiocytic intervillositis of unknown etiology (CIUE) is a rare placental lesion characterized by an intervillous mononuclear inflammatory infiltrate of maternal origin. Although the mechanism and origin of these lesions are currently not understood, they appear to be related to an immune conflict between mother and fetus cells.
  
  
  OBJECTIVE
  To clarify the inflammatory cell profile and evaluate the T regulatory lymphocyte (Treg) status in CIUE.
  
  
  METHODS
  All cases of CIUE that occurred over an 8-year period were analyzed using immunohistochemistry.
  
  
  RESULTS
  The inflammatory profile of CIUE was characterized by a clearly predominant component of histiocytic cells (80% ± 6.9) associated with some T cells (24% ± 5.7). The ratio of CD4+ versus CD8+ T cells was close to 1. This profile differs from infectious disease and chronic histiocytic villitis, the main differential diagnoses of CIUE. As for normal pregnancies most regulatory T cells were localized in the decidua basalis. Nevertheless, their appearance was also noted in the intervillous space. In both the intervillous space and the deciduas the number of Tregs gradually increased from grade 1 to 3.
  
  
  CONCLUSIONS
  We found that CIUE is associated with an increase in Treg lymphocytes in the decidua basalis and the intervillous space. Contrary to previously published data on human miscarriage, this result appears to be specific to CIUE and would support the hypothesis of an immunopathological disorder for CIUE.
authors.affiliation: Service d'Anatomie et Cytologie Pathologiques, Centre Hospitalier Universitaire Purpan, place du Docteur Baylac, TSA 40031, 31059 Toulouse cedex 9, France. ccapuani@gmail.com
authors.forename: C
authors.initials: C
authors.lastname: Capuani
authors.forename: F
authors.initials: F
authors.lastname: Meggetto
authors.forename: I
authors.initials: I
authors.lastname: Duga
authors.forename: M
authors.initials: M
authors.lastname: Danjoux
authors.forename: M
authors.initials: M
authors.lastname: March
authors.forename: O
authors.initials: O
authors.lastname: Parant
authors.forename: P
authors.initials: P
authors.lastname: Brousset
authors.forename: J
authors.initials: J
authors.lastname: Aziza
mesh_terms: D016022:Case-Control Studies; D002824:Chorionic Villi / Q000276:immunology / Q000378:metabolism / Q000473:pathology; D002908:Chronic Disease; D005260:Female; D051858:Forkhead Transcription Factors / Q000378:metabolism; D006644:Histiocytes / Q000276:immunology / Q000473:pathology; D006801:Humans; D007108:Immune Tolerance; D007150:Immunohistochemistry; D008431:Maternal-Fetal Exchange / Q000276:immunology; D010922:Placenta Diseases / Q000276:immunology* / Q000378:metabolism / Q000473:pathology*; D011247:Pregnancy; D012189:Retrospective Studies; D050378:T-Lymphocytes, Regulatory / Q000276:immunology* / Q000378:metabolism / Q000473:pathology*
chemical_list: C418974:FOXP3 protein, human; D051858:Forkhead Transcription Factors