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.