A-130 Intercomparison of Methods between Atellica Solution® and CI® Analyzers for Alanine Aminotransferase (ALT) and Aspartate Aminotransferase (AST)

Abstract Background Objectives: To verify that the results of ALT and AST measured by the Atellica Solution® analyzer (and the new CI® analyzer (Siemens Healthineers) are interchangeable. Methods For each assay, 40 patient samples were selected, covering the entire measurement range, and analyzed by both instruments. To determine the degree of agreement between the instruments, Bland Altman analysis of mean differences and Passing Bablok regression were performed. Statistics are expressed with their 95% confidence intervals (CI). The evaluation of results was carried out using the statistical program Method Validator. Results ALT: In Bland-Altman analysis, no constant systematic error was found as the 95% confidence interval of the mean difference includes zero. Similarly, in Passing Bablok regression analysis, the confidence interval of the intercept includes zero. No systematic proportional differences were observed based on the slope, as the 95% confidence interval includes the value one. AST: In both Bland-Altman and Passing Bablok regression analyses, a constant systematic error was detected as the 95% confidence interval of the observed mean difference Bland-Altman and the 95% confidence interval of the intercept of the regression line do not include zero. A slight systematic proportional difference was also observed based on the slope, as the 95% confidence interval does not include one. Conclusions Based on the observed data, we can conclude that the Atellica Solution® and CI® analyzers are interchangeable for the ALT assay. There are constant systematic differences and a slight proportional systematic error for the AST assay, which should be re-evaluated after a new calibration of the method. It is noteworthy that this variation in the data is more pronounced for high AST values, not being clinically significant differences at these concentrations; nor as pronounced in clinical decision values. Therefore, we can conclude that the Atellica Solution® and CI® analyzers are interchangeable for AST.