Classifying patients in peritoneal dialysis by mass spectrometry-based profiling

Protein equalization with dithiothreitol, protein depletion with acetonitrile and the entire proteome were assessed in conjunction with matrix assisted laser desorption ionization time of flight mass spectrometry-based profiling for a fast and effective classification of patients with renal insufficiency. Two case groups were recruited as proof of concept, patients with chronic glomerulonephritis and diabetic nephropathy. Two key tools were used to develop this approach: protein concentration with centrifugal concentrator tubes with 10KDa cut-off membranes and chemical assisted protein equalization with dithiothreitol or chemical assisted protein depletion with acetonitrile. In-house developed software was used to apply principal component analysis and hierarchical clustering to the profiles obtained. The results suggest that chemical assisted protein equalization with dithiothreitol is a methodology more robust than the other two ones, as the patients were well grouped by principal component analysis or by hierarchical clustering. [Display omitted] •Dithiothreitol is demonstrated to be an excellent reagent to equalize the proteome of peritoneal liquid dialysate.•The combination of mass-spectrometry (MALDI)-based profiling and dithiothreitol sample treatment provides the basis for an excellent system to classify patients with renal failure.•An in-house software was developed and used to classify mass-spectrometry based spectra.