title: Enzymatic pyruvate measurement by Cobas 6000 open channel assay.
abstract: BACKGROUND
  Blood pyruvate measurement in conjunction with lactic acid is useful for differentiating pyruvate dehydrogenase deficiencies from primary or secondary disorders of mitochondrial electron transport.
  
  
  METHODS
  We evaluated the analytical performance of pyruvate measurement by an enzymatic open channel assay on a Roche Cobas 6000.
  
  
  RESULTS
  The assay was linear from 0.07 to 0.50 mmol/L pyruvate. Total imprecision ranged from 15.7% to 7.1% at pyruvate levels of 0.08 to 0.31 mmol/L, respectively. Functional sensitivity was 0.07 mmol/L. The assay showed no interference by lipids or bilirubin, whereas haemolysis influenced pyruvate concentrations in a hemoglobin concentration-independent manner. Method comparison with patient samples (n = 41) showed that the Cobas 6000 enzymatic method correlated well (r2 = 0.930) with a similar enzymatic assay on a Cobas Mira platform and showed better accuracy in external control schemes.
  
  
  CONCLUSIONS
  Enzymatic pyruvate measurement by a Cobas 6000 open channel shows satisfactory analytical performance. The assay can be integrated in the automated laboratory workflow and is always ready for use thanks to its on-board reagents.
authors.affiliation: Department of Clinical Chemistry and Radioimmunology, Universitair Ziekenhuis Brussel, Laarbeeklaan 101, 1090 Brussels, Belgium. dorien.vandenbossche@uzbrussel.be
authors.forename: Dorien
authors.initials: D
authors.lastname: Van den Bossche
authors.forename: Johan
authors.initials: J
authors.lastname: Schiettecatte
authors.forename: Evilien
authors.initials: E
authors.lastname: Vekens
authors.forename: Dieter
authors.initials: D
authors.lastname: De Smet
authors.forename: Frans K
authors.initials: FK
authors.lastname: Gorus
authors.forename: Geert A
authors.initials: GA
authors.lastname: Martens
mesh_terms: D001774:Blood Chemical Analysis / Q000295:instrumentation / Q000379:methods*; D002138:Calibration; D006801:Humans; D019344:Lactic Acid / Q000097:blood; D057230:Limit of Detection; D019095:Point-of-Care Systems; D011768:Pyruvate Dehydrogenase Complex / Q000097:blood*; D015325:Pyruvate Dehydrogenase Complex Deficiency Disease / Q000097:blood / Q000175:diagnosis*; D019289:Pyruvic Acid / Q000097:blood*; D015203:Reproducibility of Results
chemical_list: D011768:Pyruvate Dehydrogenase Complex; D019344:Lactic Acid; D019289:Pyruvic Acid