Early detection of chronic kidney disease
CKD results in renal failure with patients requiring mandatory renal replacement therapy, transplantation or lifelong dialysis. Several therapeutic strategies exist for treating CKD, with the majority involving either inhibition of the renin/angiotensin system or anti-inflammatory agents. CKD therapy at an early stage can be curative, while at the later stages can only delay disease progression, highlighting the clear need for early detection. The aim of the EU-funded PROTOCLIN (Improvement of tools and portability of mass spectrometry-based clinical proteomics as applied to chronic kidney disease) project was to advance capillary electrophoresis coupled to mass spectrometry (CE-MS) technology for CKD biomarker discovery. To achieve portability, a CE-MS platform was established in a partner laboratory. As this approach required comparability of data sets, software solutions enabling the exchange and comparison of data from different instruments were developed. Validation assays confirmed portability and accuracy of both the platform and software. Further evaluation of the CE-MS platform was performed by comparison to liquid chromatography (LC-MS) using standard urine samples. The analysis clearly showed that CE-MS has higher reproducibility, attributed to calibration of the peptide migration time and elimination of carry-over effects. All partners coordinated training in all available MS platforms. Standard protocols and procedures for urine processing were established in all laboratories. The CE-MS platform was characterised for its analytical performance to further set the basis for comparison between sites. A highly relevant issue for biomarker analysis in urine is quantitation and comparative analysis, which requires normalisation of the data. To fulfil these requirements, partners developed software for normalisation and quantitation of CE-MS signals in reference to internal standards. In conclusion, project partners demonstrated that urinary proteomic biomarkers can provide clinical information for the early detection and differential diagnosis of CKD while avoiding invasive procedures. This highlights a clear benefit for the application of urinary proteomic biomarkers of CKD in the format of high-throughput screening.
Keywords
Chronic kidney disease, early detection, PROTOCLIN, mass spectrometry, proteomic biomarkers
