Optimization of icterus interference thresholds for 45 parameters on the Atellica analyzers CH930 and IM1300

The data provided by the manufacturer regarding icterus interference on the various parameters measured on Atellica analyzers are very incomplete, potentially leading to erroneous result interpretation. We aimed to evaluate icterus interference on Atellica CH930 and IM1300 for 45 parameters and to suggest revised icterus indexes for a better interpretation of results.

Pools of serum or plasma were spiked with various concentrations of either conjugated or unconjugated bilirubin. Analytes were measured in triplicate on bilirubin-spiked and native samples. Biases were calculated as the difference between the mean results of both samples. We compared the observed biases to the threshold of 10% similar to the manufacturer, and also to the total allowable errors recommended by the European Biological Variation Study (EuBIVAS).

Based on significant bias above 10%, revised icterus index thresholds were higher than manufacturer recommendations for 33 parameters, and lower for 3 parameters. Based on the EuBIVAS criteria, the thresholds were higher than manufacturer recommendations for 33 parameters, and lower for 5 parameters. The revised thresholds differed between the 2 evaluation methods in 13 cases, being less strict for some parameters with the EuBIVAS criteria, and stricter for other ones. For some parameters, the magnitude of interference differed for conjugated and unconjugated bilirubin, or depended on the concentration of the analyte.

This work provides important data that can be used to improve the interpretation of results for 45 parameters on Atellica analyzers CH930 and IM1300 in patients with hyperbilirubinemia.