title: Systemic immune presentations of Coxiella burnetii infection (Q Fever).
abstract: OBJECTIVE
  Q fever is a worldwide zoonosis caused by Coxiella burnetii. Its presentation can be atypical, delaying and complicating the diagnosis. We report 7 cases of Q fever mimicking vasculitis, systemic inflammatory disease, or auto-immune disorder.
  
  
  METHODS
  Seven cases of Q fever diagnosed between 1995 and 2007 in Nantes University Hospital (France) are described. They occurred in a nonendemic region and were selected on the basis of initial clinical presentation suggesting systemic immune disease. C. burnetii was detected using indirect immunofluorescence serology.
  
  
  RESULTS
  Q fever was acute in 4 of the 7 patients and chronic in 3. None had endocarditis. The initial presentations suggested Crohn's disease, Goodpasture's syndrome, polymyalgia rheumatica, adult-onset Still's disease, polyarteritis nodosa, giant-cell arteritis, and essential type II cryoglobulinemia. Two patients had antiphospholipid antibodies, 1 had transient IgG kappa monoclonal gammopathy, and 1 had polyclonal T CD8+ large granular lymphocyte expansion.
  
  
  CONCLUSIONS
  Clinicians must be aware of the potential diagnosis of Q fever, and C. burnetii serology is a helpful diagnostic tool in the investigation of fever of unknown origin with atypical systemic symptoms suggesting vasculitis or inflammatory disease.
authors.affiliation: Department of Infectious Diseases, University Hospital, Nantes, France.
authors.forename: Maeva
authors.initials: M
authors.lastname: Lefebvre
authors.forename: Olivier
authors.initials: O
authors.lastname: Grossi
authors.forename: Christian
authors.initials: C
authors.lastname: Agard
authors.forename: Christophe
authors.initials: C
authors.lastname: Perret
authors.forename: Patrice
authors.initials: P
authors.lastname: Le Pape
authors.forename: Didier
authors.initials: D
authors.lastname: Raoult
authors.forename: Mohamed A
authors.initials: MA
authors.lastname: Hamidou
mesh_terms: D000328:Adult; D000368:Aged; D000907:Antibodies, Bacterial / Q000097:blood; D001323:Autoantibodies / Q000097:blood; D001327:Autoimmune Diseases / Q000175:diagnosis* / Q000276:immunology; D016997:Coxiella burnetii / Q000276:immunology; D003937:Diagnosis, Differential; D005260:Female; D005602:France; D006801:Humans; D008297:Male; D008875:Middle Aged; D011778:Q Fever / Q000175:diagnosis* / Q000276:immunology; D018746:Systemic Inflammatory Response Syndrome / Q000175:diagnosis* / Q000276:immunology; D014657:Vasculitis / Q000175:diagnosis* / Q000276:immunology
chemical_list: D000907:Antibodies, Bacterial; D001323:Autoantibodies