E. M. Weissinger, H. Mischak

Background: Proteins and peptides in body fluids control the fate of cells, and consequently of organs and organisms. Hence, a thorough display of the proteins present in body fluids at any given physiological situation should give insights into the regulatory mechanisms of most diseases and support exact and unbiased diagnosis.

Methods: Here we describe the application of capillary electrophoresis (CE) coupled on-line to a time-of-flight mass spectrometer (MS) to the analysis of human urine for the identification of biomarkers for clinical diagnostic. The application of CE-MS led to the display of > 1000 polypeptides present in complex biological samples within 45-60 minutes in a single analysis run.

Results: Urine from healthy volunteers contains several hundred polypeptides which can reproducibly be found. Hence, it is possible to establish typical “normal urine” polypeptide patterns. Samples from patients with different renal diseases display polypeptide patterns that differ significantly from those obtained from healthy individuals, but are highly comparable for patients with the same diseases. Examining series of patients with the same disease allowed the establishment of polypeptide patterns typical for specific diseases.

Conclusion: A combination of several polypeptides found in urine is indicative not only for a particular disease, but also for the stage of disease and the general health of the patients. The polypeptides are defined via mass and the CE-migration time, and can be characterized further by MS/MS sequencing if necessary. The relative abundance, documenting increase or decrease of particular polypeptides and proteins, is embedded in the signal intensity. Taken together, this technology allows the generation of polypeptide patterns specific for all diseases examined to date and will support an unbiased diagnosis of disease based on these diagnostic patterns (DiaPat).

Key words: renal disease, proteomics, urine, glomerulonephritis, diabetes

Harald Mischak, PhD

Feodor-Lynen-Str. 21

D-30625 Hannover

Germany

E-mail: Mischak@bitte-keinen-spammosaiques.de

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