Comparison between analytical performances of polyclonal and monoclonal electrochemiluminescence immunoassays for NT-proBNP.
BACKGROUND
We evaluated the analytical characteristics of electrochemiluminescence (ECLIA) immunoassay for NT-proBNP (proBNP II, Roche Diagnostics, Germany) and compared its analytical performance to that of the previous polyclonal method.


METHODS
We measured NT-proBNP in EDTA plasma samples of 177 consecutive cardiac patients (69 females and 108 males; mean age 62.2+/-16.4 years, range 13 to 96 years) with monoclonal and polyclonal ECLIA methods following manufacturer's instructions using an Elecsys 2010 analyzer.


RESULTS
Monoclonal ECLIA method for NT-proBNP assay showed an imprecision (CV%) lower than 3% at the cut-off value (i.e., 150 ng/L). No significant interference was found in plasma samples containing high levels of hemoglobin, triglycerides or bilirubin. EDTA plasma showed slightly, but significantly lower NT-proBNP values than serum (on average -6.3%) and lithium-heparinized plasma (on average -3.9%) samples. Finally, a very close linear regression was found between the NT-proBNP values found by either monoclonal or polyclonal ECLIA method (monoclonal ECLIA=-72.17+1.04 polyclonal ECLIA, n=177, R=0.993).


CONCLUSIONS
The monoclonal ECLIA method showed very similar analytical characteristics with slightly lower NT-proBNP results (on average -2.5%) than the polyclonal ECLIA method. The difference between monoclonal and polyclonal methods seems to be too slight to change the reference range and decisional values for NT-proBNP assay, as previously assessed by the polyclonal ECLIA method.
Prontera
Concetta
C
Fondazione Toscana Gabriele Monasterio and CNR Institute of Clinical Physiology, Pisa, Italy.
Zucchelli
Gian Carlo
GC
Vittorini
Simona
S
Storti
Simona
S
Emdin
Michele
M
Clerico
Aldo
A
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000911:Antibodies, Monoclonal / Q000276:immunology*; D016477:Artifacts; D001774:Blood Chemical Analysis / Q000379:methods*; D004492:Edetic Acid; D004563:Electrochemistry; D005260:Female; D006493:Heparin / Q000378:metabolism; D006801:Humans; D007118:Immunoassay / Q000379:methods*; D016014:Linear Models; D049449:Luminescence; D008297:Male; D008875:Middle Aged; D020097:Natriuretic Peptide, Brain / Q000032:analysis* / Q000276:immunology; D011498:Protein Precursors / Q000032:analysis* / Q000276:immunology; D012680:Sensitivity and Specificity
D000911:Antibodies, Monoclonal; D011498:Protein Precursors; D020097:Natriuretic Peptide, Brain; D006493:Heparin; D004492:Edetic Acid