An LC-MS/MS method for serum cystatin C quantification and its comparison with two commercial immunoassays.
Clin Chem Lab Med
; 62(6): 1092-1100, 2024 May 27.
Article
em En
| MEDLINE
| ID: mdl-38253403
ABSTRACT
OBJECTIVES:
The standardization of cystatin C (CysC) measurement has received increasing attention in recent years due to its importance in estimating glomerular filtration rate (GFR). Mass spectrometry-based assays have the potential to provide an accuracy base for CysC measurement. However, a precise, accurate and sustainable LC-MS/MS method for CysC is still lacking.METHODS:
The developed LC-MS/MS method quantified CysC by detecting signature peptide (T3) obtained from tryptic digestion. Stable isotope labeled T3 peptide (SIL-T3) was spiked to control matrix effects and errors caused by liquid handling. The protein denaturation, reduction and alkylation procedures were combined into a single step with incubation time of 1â¯h, and the digestion lasted for 3.5â¯h. In the method validation, digestion time-course, imprecision, accuracy, matrix effect, interference, limit of quantification (LOQ), carryover, linearity, and the comparability to two routine immunoassays were evaluated.RESULTS:
No significant matrix effect or interference was observed with the CysC measurement. The LOQ was 0.21â¯mg/L; the within-run and total imprecision were 1.33-2.05â¯% and 2.18-3.90â¯% for three serum pools (1.18-5.34â¯mg/L). The LC-MS/MS method was calibrated by ERM-DA471/IFCC and showed good correlation with two immunoassays traceable to ERM-DA471/IFCC. However, significant bias was observed for immunoassays against the LC-MS/MS method.CONCLUSIONS:
The developed LC-MS/MS method is robust and simpler and holds the promise to provide an accuracy base for routine immunoassays, which will promote the standardization of CysC measurement.Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Cistatina C
/
Espectrometria de Massa com Cromatografia Líquida
Limite:
Humans
Idioma:
En
Ano de publicação:
2024
Tipo de documento:
Article