title: Evaluation of a new procalcitonin assay for the Siemens ADVIA Centaur with the established method on the B.R.A.H.M.S Kryptor.
abstract: BACKGROUND
  In this study, we compared the B.R.A.H.M.S Kryptor procalcitonin (PCT) assay with the newly developed ADVIA Centaur B.R.A.H.M-S PCT assay. Furthermore, the long-term stability of PCT at - 20 degrees C was assessed.
  
  
  METHODS
  Samples from 97 patients with lower respiratory tract infections were retested on both systems and compared with Passing-Bablok regression over two clinically relevant cutoff ranges for PCT, 0 - 2.0 microg/L and > 2.0 microg/L.
  
  
  RESULTS
  After storage for 2.5 to 4 years, PCT levels in patient sera declined only 3.7%. Passing-Bablok regression analysis of the total sample range (n = 97) showed that both methods correlated well (r = 0.9944), although with a deviation from the line of identity (y = 0.880x - 0.025 microg/L). Comparison of both methods within the clinically important interval of 0 - 2.0 microg/L showed acceptable correlation (y = 0.943x + 0.010 microg/L).
  
  
  CONCLUSIONS
  The ADVIA Centaur B.R.A.H.M.S PCT assay showed good correlation with the established Kryptor method. Therefore, this new technique can be used in clinical routine with the same clinical interpretation.
authors.affiliation: Department of Clinical Chemistry, Hematology and Immunology, Medical Center Alkmaar, The Netherlands. r.sanders@mca.nl
authors.forename: Robert-Jan
authors.initials: RJ
authors.lastname: Sanders
authors.forename: Marianne
authors.initials: M
authors.lastname: Schoorl
authors.forename: Ellen
authors.initials: E
authors.lastname: Dekker
authors.forename: Dominic
authors.initials: D
authors.lastname: Snijders
authors.forename: Wim G
authors.initials: WG
authors.lastname: Boersma
authors.forename: Edwin
authors.initials: E
authors.lastname: Ten Boekel
mesh_terms: D000911:Antibodies, Monoclonal / Q000276:immunology; D001331:Automation; D015415:Biomarkers; D001793:Blood Preservation; D002116:Calcitonin / Q000097:blood*; D015740:Calcitonin Gene-Related Peptide; D017714:Community-Acquired Infections / Q000097:blood; D015925:Cryopreservation; D006801:Humans; D007118:Immunoassay / Q000295:instrumentation*; D008163:Luminescent Measurements / Q000295:instrumentation*; D011014:Pneumonia / Q000097:blood; D011498:Protein Precursors / Q000097:blood*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013997:Time Factors
chemical_list: D000911:Antibodies, Monoclonal; D015415:Biomarkers; C000606589:CALCA protein, human; D011498:Protein Precursors; D002116:Calcitonin; D015740:Calcitonin Gene-Related Peptide