Technical Note: Glycolic Acid Exacerbates the Analytical Performance of Lactate Assay.

ABSTRACT

In this study, we evaluated the analytical interference of glycolic acid on several lactate assays that use lactate oxidase and dehydrogenase. Herein, we tested the effect of different concentrations of glycolic acid (0.01-46mM) on the lactate assay by using central lab and point of care (POCT) analyzers Radiometer ABL 800, Beckman AU480, Roche Cobas c502, and Abbott i-STAT. Glycolic acid concentrations as low as 0.12mM resulted in a ≥20% positive bias in lactate assay on the ABL 800 and a concentration of approximately 0.23mM resulted in >20% on the Roche Cobas c502 and Abbott i-STAT. A significant lactate gap is found at concentrations >0.06mM between the Radiometer ABL 800 and Roche Cobas c502/Abbott i-STAT. However, at concentrations ≥0.92mM, the lactate gap is very significant among all three platforms. Falsely elevated lactate levels could result in misdiagnosis.