Interlaboratory Comparison of Antibody-Free LC-MS/MS Measurements of C-peptide and Insulin.
Clin Chem
; 70(6): 855-864, 2024 Jun 03.
Article
in En
| MEDLINE
| ID: mdl-38549041
ABSTRACT
BACKGROUND:
The enhanced precision and selectivity of liquid chromatography-tandem mass spectrometry (LC-MS/MS) makes it an attractive alternative to certain clinical immunoassays. Easily transferrable work flows could help facilitate harmonization and ensure high-quality patient care. We aimed to evaluate the interlaboratory comparability of antibody-free multiplexed insulin and C-peptide LC-MS/MS measurements.METHODS:
The laboratories that comprise the Targeted Mass Spectrometry Assays for Diabetes and Obesity Research (TaMADOR) consortium verified the performance of a validated peptide-based assay (reproducibility, linearity, and lower limit of the measuring interval [LLMI]). An interlaboratory comparison study was then performed using shared calibrators, de-identified leftover laboratory samples, and reference materials.RESULTS:
During verification, the measurements were precise (2.7% to 3.7%CV), linear (4 to 15â ng/mL for C-peptide and 2 to 14â ng/mL for insulin), and sensitive (LLMI of 0.04 to 0.10â ng/mL for C-peptide and 0.03â ng/mL for insulin). Median imprecision across the 3 laboratories was 13.4% (inter-quartile range [IQR] 11.6%) for C-peptide and 22.2% (IQR 20.9%) for insulin using individual measurements, and 10.8% (IQR 8.7%) and 15.3% (IQR 14.9%) for C-peptide and insulin, respectively, when replicate measurements were averaged. Method comparison with the University of Missouri reference method for C-peptide demonstrated a robust linear correlation with a slope of 1.044 and r2 = 0.99.CONCLUSIONS:
Our results suggest that combined LC-MS/MS measurements of C-peptide and insulin are robust and adaptable and that standardization with a reference measurement procedure could allow accurate and precise measurements across sites, which could be important to diabetes research and help patient care in the future.
Full text:
1
Database:
MEDLINE
Main subject:
C-Peptide
/
Tandem Mass Spectrometry
/
Insulin
Limits:
Humans
Language:
En
Journal:
Clin Chem
/
Clin. chem
/
Clinical chemistry
Journal subject:
QUIMICA CLINICA
Year:
2024
Type:
Article
Affiliation country:
United States