Effect of Different Sample Types and Stability after Blood Collection of N-Terminal Pro-B-Type Natriuretic Peptide as Measured with Roche Elecsys System

Abstract

any immunoassay, with or without an extraction and a purification step, requires validation by a definitive or reference method before being considered a gold standard (2 ).We have not made an arbitrary statement that extraction/chromatography RIAs for testosterone do not work. Our point is that there are no convincing data showing that they do work. The only existing reports, from two independent sources (1, 5 ), that compared extraction/ chromatography RIA with gas chromatography-mass spectrometry show that there are considerable problems with these analyses. Until an extraction/chromatography RIA has been properly validated the results generated from such tests are subject to question.We appreciate the opportunity to further emphasize the need for proper validation of steroid immunoassays. Ciba Corning ACS:180 Direct total testosterone assay can be used on female sera.

Quality Specifications for B-Type Natriuretic Peptide Assays

“…Samples are also stable for at least 1 year when stored at Ϫ80°C, and five freeze-thaw cycles had no effect on analyte concentration (36 ). For the Roche assay, a small but statistically significant difference in results between heparin plasma and serum was shown in one study (37 ), but was not confirmed in others (35 ). EDTA plasma gave a consistent negative bias (6 -10% on average) compared with matched serum and heparin-plasma samples, although the studies did not indicate the variability among samples (38 ).…”

The Relationship of NT-proBNP and Dialysis Parameters with Outcome of Incident Haemodialysis Patients: Results from the Membrane Permeability Outcome Study

“…NT-proBNP in serum samples from month 0 were analysed centrally using the Roche Elecsys® kit, an electrochemiluminescence ‘sandwich' immunoassay based on polyclonal antibodies against NT-proBNP [20]. …”

Pro-Brain Natriuretic Peptide is a Sensitive Marker for Detecting Cardiac Metastases in Patients with Non-Small Cell Lung Cancer

“…These peptides arestableandcaneasilybedetectedandquantifiedbyimmunometricassaysinserumorplasma.ThemolecularweightoftheseB-typenatriuretic peptidesdiffers,andbecauseNT-pro-BNPisnotclearedactively,ithasa longerhalf-life,withplasmalevels2-10timeshigherthanBNP [13].Both BNP and NT-pro-BNP levels were measured in all cases. Plasma BNP concentrations were measured with a specific immunoradiometric assay for human BNP using a commercially available kit (Shionogi, Osaka, Japan) and the BNP AxSYM kit (Abbott Inc., Abbott Park, IL, USA), asandwich-typeimmunoassaybasedon2monoclonalantibodies [14,15]. NT-pro-BNPlevelsweremeasuredinasinglebatchafterthefrozenspecimenswerethawed [13][14][15]usinganautomatednon-competitiveimmunoradiometric assay (Roche Diagnostics Inc., Mannheim, Germany) on an Elecsys1010analyser(RocheDiagnosticsInc.…”

“…Plasma BNP concentrations were measured with a specific immunoradiometric assay for human BNP using a commercially available kit (Shionogi, Osaka, Japan) and the BNP AxSYM kit (Abbott Inc., Abbott Park, IL, USA), asandwich-typeimmunoassaybasedon2monoclonalantibodies [14,15]. NT-pro-BNPlevelsweremeasuredinasinglebatchafterthefrozenspecimenswerethawed [13][14][15]usinganautomatednon-competitiveimmunoradiometric assay (Roche Diagnostics Inc., Mannheim, Germany) on an Elecsys1010analyser(RocheDiagnosticsInc. ).TheRocheNT-pro-BNP assay combines a capture antibody targeting pro-BNP amino acids 1-21 withadetectionantibodyrecognizingpro-BNPaminoacids39-50.…”