[Evaluation of the analytical performance characteristics of NT-proBNP immunoassay on dimension RxL-HM (Dade Behring)].

Background: Plasma B-type natriuretic peptide (BNP) and N terminal prohormone (NT-proBNP) are promising markers for the diagnosis, prognosis and follow up of heart failure. Elevated levels have been associated with adverse long-term outcome in patients with acute coronary syndromes.

Method: The analytical performance of a new automated NT-proBNP assay on Dimension-HM system (Dade Behring) and comparison with the results obtained with the Roche Diagnostics NT-proBNP assays using the Elecsys instrument have been evaluated according to the Valtec protocol.

Results: Total imprecision (CV) was below 9% for NT-proBNP concentrations between 100 and 10,000 pg/mL using quality control samples and pooled patients' plasma. Analytical sensitivity was found 9.8 pg/mL the day of calibration and 10.1 pg/mL ten days later. Dilution linearity showed overall recovery between 98.4 and 104.7%. No hook effect was observed for NT-proBNP concentration up to 96,000 pg/mL. The interference of turbidity was below 4%. Hemoglobin interfered negatively with assay upper 240 micromol/L but less than 10%. A precision profile demonstrated a total imprecision of 10% CV at a NT-proBNP concentration of 70 pg/mL and 20% at 30 pg/mL. Dimension results highly correlated (r = 0.99) with Roche Elecsys NT-proBNP.