Extremely elevated C-reactive protein

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. Conclusion: 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. (C) 2006 European Federation of Internal Medicine. Published by Elsevier B.V. All rights reserved.