title: Serial determinations of neutrophil CD64 expression for the diagnosis and monitoring of sepsis in critically ill patients.
abstract: BACKGROUND
  Early identification of sepsis is important to be able to initiate timely therapy and optimize survival. Neutrophil CD64 (nCD64) expression has been proposed as a potential marker of sepsis.
  
  
  METHODS
  In this prospective observational study, adult patients admitted to our 34-bed medico-surgical department of intensive care over a 3.5-month period were included. Neutrophil CD64 expression was measured by flow cytometry at admission and daily until discharge or death. Blood C-reactive protein (CRP) level was measured routinely. Diagnosis of sepsis was recorded and appropriateness of empirical antibiotic treatment was established post hoc.
  
  
  RESULTS
  Of the 548 patients included, 468 had flow cytometry measurements within 24 hours after admission, of whom 103 had sepsis. Septic patients had higher admission nCD64 expression than did nonseptic patients (P < .001). A cutoff admission nCD64 expression of 230 median fluorescence intensity (MFI) identified sepsis with a sensitivity of 89% (81%-94%) and specificity of 87% (83%-90%). When combining CRP and nCD64 expression, an abnormal result for both was associated with a 92% probability of sepsis, whereas sepsis was ruled out with a probability of 99% if both were normal. Septic patients receiving inappropriate empirical antibiotics had persistently elevated nCD64 expression, whereas expression decreased over time in patients receiving appropriate antibiotics. In nonseptic patients, an increase in nCD64 expression ≥40 MFI predicted intensive care unit (ICU)-acquired infection (n = 29) with a sensitivity of 88% and specificity of 65%.
  
  
  CONCLUSIONS
  Measurement of nCD64 expression at ICU admission, especially when combined with CRP concentrations, is useful in diagnosing sepsis. Serial determinations of nCD64 could be used for monitoring purposes.
authors.affiliation: Department of Intensive Care.
authors.forename: Aikaterini
authors.initials: A
authors.lastname: Dimoula
authors.forename: Olivier
authors.initials: O
authors.lastname: Pradier
authors.forename: Zaina
authors.initials: Z
authors.lastname: Kassengera
authors.forename: Dyanne
authors.initials: D
authors.lastname: Dalcomune
authors.forename: Hulya
authors.initials: H
authors.lastname: Turkan
authors.forename: Jean-Louis
authors.initials: JL
authors.lastname: Vincent
mesh_terms: D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000097:blood; D002097:C-Reactive Protein / Q000378:metabolism; D016638:Critical Illness; D003428:Cross Infection / Q000097:blood / Q000175:diagnosis / Q000276:immunology; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D007362:Intensive Care Units; D008297:Male; D008875:Middle Aged; D009504:Neutrophils / Q000166:cytology / Q000276:immunology*; D011379:Prognosis; D017452:Receptors, IgG / Q000097:blood*; D018805:Sepsis / Q000097:blood* / Q000175:diagnosis / Q000276:immunology
chemical_list: D015415:Biomarkers; D017452:Receptors, IgG; D002097:C-Reactive Protein
keywords: C-reactive protein; ICU-acquired infection; biomarker; intensive care unit; prognosis