BACKGROUND: The availability of a suitable matrix reference material is essential for standardization of the immunoassays used to measure serum proteins. The earlier serum protein reference material ERM-DA470 (previously called CRM470), certified in 1993, has led to a high degree of harmonization of the measurement results. A new serum protein material has now been prepared and its suitability in term of homogeneity and stability has been verified; after characterization, the material has been certified as ERM-DA470k/IFCC.
METHODS: We characterized the candidate reference material for 14 proteins by applying a protocol that is considered to be a reference measurement procedure, by use of optimized immunoassays. ERM-DA470 was used as a calibrant.
RESULTS: For 12 proteins [alpha2 macroglobulin (A2M), alpha1 acid glycoprotein (orosomucoid, AAG), alpha1 antitrypsin (alpha1-protease inhibitor, AAT), albumin (ALB), complement 3c (C3c), complement 4 (C4), haptoglobin (HPT), IgA, IgG, IgM, transferrin (TRF), and transthyretin (TTR)], the results allowed assignment of certified values in ERM-DA470k/IFCC. For CRP, we observed a bias between the lyophilized and liquid frozen materials, and for CER, the distribution of values was too broad. Therefore, these 2 proteins were not certified in the ERM-DA470k/IFCC. Different value transfer procedures were tested (open and closed procedures) and found to provide equivalent results.
CONCLUSIONS: A new serum protein reference material has been produced, and values have been successfully assigned for 12 proteins.
ZEGERS Ingrid;
KELLER Thomas;
SCHREIBER Wiebke;
SHELDON Joanna;
ALBERTINI Roberto;
BLIRUP-JENSEN Soren;
JOHNSON M.;
TRAPMANN Stefanie;
EMONS Hendrik;
MERLINI Giampaolo;
SCHIMMEL Heinz;
2010-12-07
AMER ASSOC CLINICAL CHEMISTRY
JRC58476
0009-9147,
https://publications.jrc.ec.europa.eu/repository/handle/JRC58476,
10.1373/clinchem.2010.148809,
