title: Extremely elevated C-reactive protein.
abstract: BACKGROUND
  C-reactive protein (CRP) is a widely used inflammatory marker. Yet, the clinical significance and outcome of extremely elevated CRP levels are poorly characterized.
  
  
  METHODS
  We collected all patients seen at a university hospital in 2004 with at least one CRP level above 500 mg/l and retrospectively analyzed their electronic files, focusing on patient characteristics, clinical diagnosis, microbiology and vital outcome.
  
  
  RESULTS
  CRP was above 500 mg/l in 130 patients with a median age of 62 years. Patient characteristics, settings, etiologies of inflammation, comorbidities and microbiology varied widely. Infections, mainly bacterial, accounted for 88% of episodes. Outcome was fatal in 36% of all patients and in 61% of patients with active malignancies.
  
  
  CONCLUSIONS
  A wide variety of infections, especially bacterial, that are generally readily identified account for the majority of instances of extreme CRP elevation. Mortality is high, certainly in oncological patients.
authors.affiliation: Department of General Internal Medicine, University Hospital, Leuven, Herestraat 49, B-3000 Leuven, Belgium.
authors.forename: Steven
authors.initials: S
authors.lastname: Vanderschueren
authors.forename: Dries
authors.initials: D
authors.lastname: Deeren
authors.forename: Daniël C
authors.initials: DC
authors.lastname: Knockaert
authors.forename: Herman
authors.initials: H
authors.lastname: Bobbaers
authors.forename: Xavier
authors.initials: X
authors.lastname: Bossuyt
authors.forename: Willy
authors.initials: W
authors.lastname: Peetermans