Analytical performance of the Synchron LX20 Pro, BN trade mark II and IMMAGE high sensitivity C-reactive protein assays and concordance in cardiovascular risk stratification.

BACKGROUND

C-reactive protein (CRP) can provide valuable prognostic information for risk of cardiovascular events. Several automated high sensitivity CRP immunoassays are currently available for risk assessment.

METHODS

The analytical performance of the Synchron LX20 Pro, BN II and IMMAGE high sensitivity CRP assays were evaluated and concordance within cardiovascular risk tertiles was examined for 529 serum samples.

RESULTS

All three assays exhibited satisfactory between-run imprecision based on CVs< or =9.0% over a wide range of CRP concentrations. The LX20 Pro and BN II were linear over an extensive measuring range, whereas the IMMAGE exhibited a slight deviation from linearity producing results with a positive bias at CRP levels between 0.7 and 2.6 mg/l. Moderately hemolyzed samples interfered with the LX20 Pro and IMMAGE CRP assays, whereas moderate lipemia interfered with the BN II. Correlation studies revealed that the LX20 Pro and IMMAGE produced results 8.2% lower and 5.1% lower, respectively, compared with the BN II. There was good agreement among methods for cardiovascular risk assessment.

CONCLUSIONS

All three CRP assays exhibited acceptable analytical performance for cardiovascular risk assessment. Although results by the LX20 Pro and IMMAGE were lower than the BN II, there was good agreement within each cardiovascular risk assessment tertile.