Finding diabetic nephropathy biomarkers in the plasma peptidome by high-throughput magnetic bead processing and MALDI-TOF-MS analysis.
OBJECTIVE
Diabetic nephropathy (DN) is the most common cause of end-stage renal disease and improved biomarkers would help identify high-risk individuals. The aim of this study was to discover candidate biomarkers for DN in the plasma peptidome in an in-house cross-sectional cohort (n=122) of type 1 diabetic patients diagnosed with normo-, micro-, and macroalbuminuria.


RESULTS
Automated, high-throughput, and reproducible (interassay median CV: 13-14%) plasma peptide profiling protocols involving RPC18 and weak cation exchange magnetic beads on a liquid handling workstation with a MALDI-TOF-MS readout were successfully established. Using these protocols and a combined univariate (Kruskal-Wallis) and multivariate (independent component analysis) statistical analysis approach, ten single peptides and three multi-peptide candidate biomarkers were found. Employment of RPC18 and weak cation exchange magnetic beads proved to be complementary.


CONCLUSIONS
The proteins found in this study, including C3f and apolipoprotein C-I, represent new candidate biomarkers for DN from the plasma peptidome. The automated procedures and implementation of independent components analysis provide a fast and informative system for analyzing individual patient samples in protein biomarker discovery.
Hagedorn Research Institute, Novo Nordisk A/S, Gentofte, Denmark.
Henning G
HG
Hansen
Julie
J
Overgaard
Maria
M
Lajer
Frantisek
F
Hubalek
Peter
P
Højrup
Lykke
L
Pedersen
Lise
L
Tarnow
Peter
P
Rossing
Flemming
F
Pociot
James N
JN
McGuire
D053302:Apolipoprotein C-I / Q000097:blood; D057205:Automation, Laboratory; D015415:Biomarkers / Q000097:blood*; D003179:Complement C3b / Q000032:analysis / Q000378:metabolism; D003928:Diabetic Nephropathies / Q000097:blood* / Q000175:diagnosis; D006801:Humans; D018189:Immunomagnetic Separation / Q000379:methods*; D008297:Male; D008875:Middle Aged; D010455:Peptides / Q000097:blood*; D015203:Reproducibility of Results; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*
D053302:Apolipoprotein C-I; D015415:Biomarkers; D010455:Peptides; C521185:complement C3f-des-arginine; D003179:Complement C3b