Automated Multiplex LC-MS/MS Assay for Quantifying Serum Apolipoproteins A-I, B, C-I, C-II, C-III, and E with Qualitative Apolipoprotein E Phenotyping

作者：van den Broek Irene; Romijn Fred P H T M; Nouta Jan; van der Laarse Arnoud; Drijfhout Jan W; Smit Nico P M; van der Burgt Yuri E M; Cobbaert Christa M^*

来源：Clinical Chemistry, 2016, 62(1): 188-197.

DOI：10.1373/clinchem.2015.246702

BACKGROUND: Direct and calculated measures of lipoprotein fractions for cardiovascular risk assessment suffer from analytical inaccuracy in certain dyslipidemic and pathological states, most commonly hypertriglyceridemia. LC-MS/MS has proven suitable for multiplexed quantification and phenotyping of apolipoproteins We developed and provisionally validated an automated assay for quantification of apolipoprotein (apo) A-I, B, C-I, C-II, C-III, and E and simultaneous qualitative assessment of apoE phenotypes.
METHODS: We used 5 value-assigned human serum pools for external calibration. Serum proteins were denatured, reduced, and alkylated according to standard mass spectrometry based proteomics procedures. After trypsin digestion, peptides were analyzed by LC-MS/MS. For each peptide, we measured 2 transitions. We compared LC-MS/MS results to those obtained by an immunoturbidimetric assay or ELISA.
RESULTS: Intraassay CVs were 2.3%-5.5%, and total CVs were 2.5%-5.9%. The LC-MS/MS assay correlated (R = 0.975-0.995) with immunoturbidimetric assays with Conformite Europeenne marking for apoA-I, apoB, apoC-II, apoC-III, and apoE in normotriglyceridemic (n = 54) and hypertriglyceridemic (n = 46) sera. Results were interchangeable for apoA-I <= 3.0 g/L (Deming slope 1.014) and for apoB-100 <= 1.8 g/L (Deming slope 1.016) and were traceable to higher-order standards.
CONCLUSIONS: The multiplex format provides an opportunity for new diagnostic and pathophysiologic insights into types of dyslipidemia and allows a more personalized approach for diagnosis and treatment of lipid abnormalities.

• 出版日期2016-1