Cerebrospinal fluid proteome comparison between multiple sclerosis patients and controls

OBJECTIVES

The aim of the present study was to identify proteins in cerebrospinal fluid (CSF) with different abundance between patients with relapsing-remitting multiple sclerosis (RRMS) and controls. Such proteins may be diagnostic biomarkers and contribute with novel information about the disease pathogenesis.

MATERIALS AND METHODS

Cerebrospinal fluid from patients with RRMS (n = 17) and controls (n = 17) were trypsin digested and analyzed in a label-free fashion using liquid chromatography mass spectrometry. The resulting data were analyzed using SearchGUI, PeptideShaker, and the Progenesis software.

RESULTS

Two hundred and ninety-one proteins were identified, of which 32 were significantly differentially abundant between the patients with RRMS and controls (P-value ≤ 0.05, two or more peptides quantified). Among these were proteins which previously have been linked to MS, including immunoglobulin subunits, vitamin D-binding protein, apolipoprotein D, kallikrein-6, neuronal pentraxin receptor, Dickkopf-related protein 3, and contactin-1.

CONCLUSION

The study provides an overview of differentially abundant proteins between RRMS and controls, and a few of these are further discussed. It should be stressed that a larger verification study is needed to reveal the potential value of these proteins as biomarkers for RRMS and their involvement in the disease pathogenesis.

A consensus protocol for the standardization of cerebrospinal fluid collection and biobanking

There is a long history of research into body fluid biomarkers in neurodegenerative and neuroinflammatory diseases. However, only a few biomarkers in CSF are being used in clinical practice. One of the most critical factors in CSF biomarker research is the inadequate powering of studies because of the lack of sufficient samples that can be obtained in single-center studies. Therefore, collaboration between investigators is needed to establish large biobanks of well-defined samples. Standardized protocols for biobanking are a prerequisite to ensure that the statistical power gained by increasing the numbers of CSF samples is not compromised by preanalytical factors. Here, a consensus report on recommendations for CSF collection and biobanking is presented, formed by the BioMS-eu network for CSF biomarker research in multiple sclerosis. We focus on CSF collection procedures, preanalytical factors, and high-quality clinical and paraclinical information. The biobanking protocols are applicable for CSF biobanks for research targeting any neurologic disease.

Proteomic-based biomarker discovery with emphasis on cerebrospinal fluid and multiple sclerosis

Discovery of disease specific biomarkers in human body fluids has become an important challenge in clinical proteomics. Facing the increasing threat of degenerative and disabling diseases like cancer, cardiovascular, neurological and inflammatory diseases in large parts of the world's population, there is an urgent need to improve early diagnostics. In this review we discuss possibilities and limitations connected to using mass spectrometry based proteomics in the search for novel biomarkers, with focus on multiple sclerosis as a typical representative for the large group of non-curable degenerative and disabling disease with the lack of specific tests for early diagnosis. Careful control of the pre-analytical phase including sampling, storage and fractionation of samples, in addition to a thoroughly considered patient selection, is important in order to avoid false biomarkers to appear in the resulting mass spectra. Furthermore, advanced computational tools are needed in order to discover potential biomarkers from the enormous data amounts generated by the mass spectrometers. The development of such computer tools is a research field currently in the start phase and could prove to be a bottle neck in the biomarker discovery the next years. Therefore, a rather detailed review of the most used computational and pre-analytical methods is given in this review. Mass spectrometry based biomarker discovery is undoubtedly still in its early infancy. However, in light of the potential of this technology to provide deep coverage of the body fluid proteomes, it will certainly consolidate its role in developing molecular medicine into clinical practice.