title: Chlamydia pneumoniae--a new causative agent of reactive arthritis and undifferentiated oligoarthritis.
abstract: OBJECTIVE
  To examine whether reactive arthritis (ReA) known to occur after a urogenital infection with Chlamydia trachomatis can also follow an infection with Chlamydia pneumoniae, a recently described species of Chlamydiae that is a common cause of respiratory tract infections.
  
  
  METHODS
  Specific antibodies (microimmunofluorescence test) and lymphocyte proliferation to C trachomatis and C pneumoniae in paired samples of peripheral blood and synovial fluid were investigated in 70 patients with either reactive arthritis (ReA) or undifferentiated oligoarthritis (UOA).
  
  
  RESULTS
  Five patients with acute ReA after an infection with C pneumoniae are reported. Three had a symptomatic preceding upper respiratory tract infection and two had no such symptoms. In all patients a C pneumoniae-specific lymphocyte proliferation in synovial fluid and a high specific antibody titre suggesting an acute infection was found.
  
  
  CONCLUSIONS
  C pneumoniae needs to be considered a new important cause of reactive arthritis.
authors.affiliation: Department of Medicine, Klinikum Steglitz, Free University of Berlin, Germany.
authors.forename: J
authors.initials: J
authors.lastname: Braun
authors.forename: S
authors.initials: S
authors.lastname: Laitko
authors.forename: J
authors.initials: J
authors.lastname: Treharne
authors.forename: U
authors.initials: U
authors.lastname: Eggens
authors.forename: P
authors.initials: P
authors.lastname: Wu
authors.forename: A
authors.initials: A
authors.lastname: Distler
authors.forename: J
authors.initials: J
authors.lastname: Sieper
mesh_terms: D000208:Acute Disease; D000293:Adolescent; D000328:Adult; D000368:Aged; D000907:Antibodies, Bacterial / Q000032:analysis; D000917:Antibody Formation; D001168:Arthritis / Q000382:microbiology; D016918:Arthritis, Reactive / Q000382:microbiology*; D002455:Cell Division / Q000502:physiology; D002690:Chlamydia Infections / Q000150:complications* / Q000276:immunology; D016993:Chlamydophila pneumoniae / Q000276:immunology; D005260:Female; D006801:Humans; D007111:Immunity, Cellular; D008214:Lymphocytes / Q000166:cytology; D008297:Male; D008875:Middle Aged; D000091402:Prohibitins; D012141:Respiratory Tract Infections / Q000150:complications* / Q000276:immunology
chemical_list: D000907:Antibodies, Bacterial; C000717331:PHB2 protein, human; D000091402:Prohibitins