title: Chlamydia infection and lymphomas: association beyond ocular adnexal lymphomas highlighted by multiple detection methods.
abstract: OBJECTIVE
  Chlamydia psittaci (Cp) has been associated to ocular adnexal lymphomas (OAL) with variable geographic distribution. Herein, we used multiple Chlamydia detection tools to identify Cp elementary bodies-containing cell and to assess Cp prevalence in both nodal and extranodal lymphomas.
  
  
  METHODS
  TETR-PCR, immunohistochemistry, immunofluorescence, electron microscopy, and laser-capture microdissection were done in 35 OALs to define their effect in Chlamydia detection and, moreover, to identify the Cp cellular carrier. Cp prevalence was screened by TETR-PCR in 205 extraorbital lymphomas and 135 nonneoplastic controls.
  
  
  RESULTS
  Twenty-six (74%) OALs were associated with Cp infection: immunohistochemistry, immunofluorescence, and laser-capture microdissection-assisted PCR showed that monocytes/macrophages were the Cp carriers; electron microscopy showed the presence of intact Cp elementary bodies into these cells. Immunohistochemistry and TETR-PCR showed a 70% concordance rate (P = 0.001). Cp DNA was equally prevalent in non-OAL, nodal, and extranodal lymphomas: among the latter, it was more common in diffuse large B-cell lymphomas of the skin (P = 0.03) and Waldeyer's ring.
  
  
  CONCLUSIONS
  This multiparametric approach shows, for the first time, that monocytes/macrophages are the carriers of Cp, Cp seems preferentially associated with lymphomas arising in organs primarily exposed to antigens. The clinical implications of these findings deserve to be prospectively investigated.
authors.affiliation: Pathology Unit, San Raffaele Scientific Institute, Milano, Italy. ponzoni.maurilio@hsr.it
authors.forename: Maurilio
authors.initials: M
authors.lastname: Ponzoni
authors.forename: Andrés J M
authors.initials: AJ
authors.lastname: Ferreri
authors.forename: Massimo
authors.initials: M
authors.lastname: Guidoboni
authors.forename: Antonia A
authors.initials: AA
authors.lastname: Lettini
authors.forename: Maria Giulia
authors.initials: MG
authors.lastname: Cangi
authors.forename: Elisa
authors.initials: E
authors.lastname: Pasini
authors.forename: Luciano
authors.initials: L
authors.lastname: Sacchi
authors.forename: Lorenza
authors.initials: L
authors.lastname: Pecciarini
authors.forename: Stefano
authors.initials: S
authors.lastname: Grassi
authors.forename: Elena
authors.initials: E
authors.lastname: Dal Cin
authors.forename: Rosalba
authors.initials: R
authors.lastname: Stefano
authors.forename: Simone
authors.initials: S
authors.lastname: Magnino
authors.forename: Riccardo
authors.initials: R
authors.lastname: Dolcetti
authors.forename: Claudio
authors.initials: C
authors.lastname: Doglioni
mesh_terms: D002690:Chlamydia Infections / Q000453:epidemiology*; D002691:Chlamydophila psittaci / Q000235:genetics / Q000302:isolation & purification; D004269:DNA, Bacterial / Q000032:analysis; D005134:Eye Neoplasms / Q000453:epidemiology* / Q000382:microbiology; D006801:Humans; D008223:Lymphoma / Q000453:epidemiology* / Q000382:microbiology; D008264:Macrophages / Q000382:microbiology; D009000:Monocytes / Q000382:microbiology; D016133:Polymerase Chain Reaction; D009956:Psittacosis / Q000453:epidemiology
chemical_list: D004269:DNA, Bacterial