Medical results generated by CE-IVDs or in-house tests should be traceable to higher order Reference Measurement Systems (RMS), such as IFCC endorsed Reference Measurement Procedures (RMPs) and Reference Materials (RMs). Currently, serum apolipoprotein (a) (apo(a)) is recognized as a novel risk factor for cardiovascular risk assessment and patient management. Former RMS for serum apo(a) is no longer available, consequently, an SI-traceable, ideally multiplexed, and sustainable RMS for apo(a) is needed. A mass spectrometry (MS)-based candidate RMP (cRMP) for apo(a) was developed using quantitative bottom-up proteomics targeting three proteotypic peptides. The method was provisionally validated according to ISO 15193 using a single human serum based calibrator traceable to the former WHO-IFCC RMS. The quantitation of serum apo(a) was by design independent of its size polymorphism, was linear from 3.8 to 456 nmol/L, and had a lower limit of quantitation for apo(a) of 3.8 nmol/L using peptide LFLEPTQADIALLK. Interpeptide agreement within individual proteins showed Pearson’s Rs of 0.987 and 0.984 for peptides GISSTVTGR and TPENYPNAGLTR, and method comparison indicated good correspondence with slopes of 0.977, 1.033 and 1.085 for LFLEPTQADIALLK, GISSTVTGR and TPENYPNAGLTR.

RUHAAK L. Renee;  ROMIJN Fred P.H.T.M.;  BEGCEVIC BRKOVIC Ilijana;  KUKLENYIK Zsusanna;  DITTRICH Julia;  CEGLAREK Uta;  HOONAGLE Andrew N.;  ALTHAUS Harald;  ANGLES-CANO Eduardo;  COASSIN Stefan;  DELATOUR Vincent;  DEPREZ Liesbet;  DIKAIOS Ioannis;  KOSTNER Gerhard M.;  KRONENBERG Florian;  LYLE Alicia;  PRINZING Urban;  VESPER Hubert;  COBBAERT Christa M.; 

2023-03-13

OXFORD UNIV PRESS INC

JRC131276

0009-9147 (online),   

https://academic.oup.com/clinchem/article/69/3/251/6987871?login=true,    https://publications.jrc.ec.europa.eu/repository/handle/JRC131276,   

10.1093/clinchem/hvac204 (online),