Evaluation of the In Vitro Interference of Hemoglobin, Lipids, and Bilirubin on the Measurement of Plasma Advanced Oxidation Protein Products.

BACKGROUND: The pre-analytical phase is the most vulnerable and contributes to the majority of errors in laboratory assays. Therefore, the aim of this study was to evaluate in vitro interference of hemoglobin, lipids, and bilirubin on measurement of plasma advanced oxidation protein products (AOPPs).

METHODS: AOPPs were measured in a sample spiked with increasing concentrations of hemoglobin, Intralipid® 20% or bilirubin. Then, the relative deviation of the result from the nonspiked baseline value was calculated.

RESULTS: We found that all interferents analyzed influenced AOPPs baseline value significantly. Hemoglobin produced a non-linear negative bias, with a maximum decrease of 21.1%. Otherwise, lipids and bilirubin produced a positive bias, ranging from 20.0 to 90.9%, and 12.1 to 33.2%, respectively.

CONCLUSIONS: The addition of interferents produced a significant bias in the measurement of AOPPs and in different degrees at the majority of concentrations added.