Systematic differences between BNP immunoassays: Comparison of methods using standard protocols and quality control materials

• Published in: Clinica chimica acta Vol. 424; pp. 287 - 291
• Main Authors: Franzini, Maria, Masotti, Silvia, Prontera, Concetta, Ripoli, Andrea, Passino, Claudio, Giovannini, Stefania, Zucchelli, Giancarlo, Clerico, Aldo
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 23.09.2013
• Subjects: BNP; Case-Control Studies; Heart failure; Heart Failure - blood; Heart Failure - diagnosis; Humans; Immunoassay; Immunoassay - methods; Immunoassay - standards; Immunoassay - statistics & numerical data; Italy; Laboratories - standards; Limit of Detection; Method comparison; Natriuretic Peptide, Brain - blood; Observer Variation; Quality Control; Reproducibility of Results; Italy; Heart failure; Method comparison; Immunoassay; BNP; Quality control
• ISSN: 0009-8981; 1873-3492; 1873-3492
• DOI: 10.1016/j.cca.2013.07.001

Recent studies suggested that there are marked systematic differences among BNP immunoassays. In this study we compared the BNP data and clinical results obtained with different immunoassays, including a new method (ST-AIA-PACK, TOSOH Corporation). BNP was measured on plasma-EDTA samples of healthy subjects (HS, n=126) and patients with heart failure (HF, n=31 NYHA I, II; n=46 NYHA III, IV) using the ST-AIA-PACK and the Triage Biosite (Beckman Coulter) methods. Control samples distributed in the CardioOrmoCheck external quality assessment were also measured with TOSOH and the most used BNP immunoassays in Italy. TOSOH method showed a good correlation (R=0.976; n=327) but a mean bias (−46.9%) compared to Triage Biosite. On the base of the results obtained in 10 samples of the CardioOrmoCheck study, TOSOH method showed a strict agreement with ADVIA Centaur, while it underestimated BNP in comparison with Triage (−52.5%) and ARCHITECT methods (−39.4%). The agreement of ST-AIA-PACK and Triage Biosite methods for classification of HF patients was tested using 100ng/L of BNP; the positive agreement between methods was 65%, overall agreement was 73%. Our results confirm that there are marked differences in measured values among commercial methods for BNP assay. •There are marked differences in measured values among commercial methods for BNP assay•The cut-off for heart failure diagnosis should be method specific•Classification agreement at 100ng/L of BNP between TOSOH and Triage methods was 73%•The cut-off for BNP TOSOH is 21.5ng/L vs. 40.0ng/L of the Triage Biosite method•TOSOH assay underestimate BNP in comparison with Triage (−52%) and ARCHITECT (−39%)