Performance characteristics of an automated high-sensitivity C-reactive protein assay on the Dimension RXL analyzer

Background: C-reactive protein (CRP) is a nonspecific marker of inflammation that can be used as a marker for atherosclerotic risk. This application requires increased precision at low CRP concentrations compared to traditional assays. Methods: The Dimension RXL is an automated chemistry analyzer for central laboratory use. The limit of detection, limit of quantification, linearity and imprecision of a high-sensitivity CRP assay developed for it were assessed. Method comparison studies were performed using samples both inside and outside the reference interval. The presence of a prozone effect was also evaluated. Results: The limit of detection was 0.7 mg/l. The method was linear from 2 to 60 mg/l and from 1 to 60 mg/l using systematic error limits of 10% and 20%, respectively. The total imprecision was