Systematic analysis of the cerebrospinal fluid proteome of fibromyalgia patients.

Fibromyalgia (FM) is a syndrome characterized by widespread muscular pain, fatigue and functional symptoms, which is known to be difficult to diagnose as the various symptoms overlap with many other conditions. Currently, there are no biomarkers for FM, and the diagnosis is made subjectively by the clinicians. We have performed shotgun proteomics on cerebrospinal fluid (CSF) from FM patients and non-pain controls to find potential biomarker candidates for this syndrome. Based on our multivariate and univariate analyses, we found that the relative differences in the CSF proteome between FM patients and controls were moderate. Four proteins, important to discriminate FM patients from non-pain controls, were found: Apolipoprotein C-III, Galectin-3-binding protein, Malate dehydrogenase cytoplasmic and the neuropeptide precursor protein ProSAAS. These proteins are involved in lipoprotein lipase (LPL) activity, inflammatory signaling, energy metabolism and neuropeptide signaling. SIGNIFICANCE: Fibromyalgia is present in as much as 2% of the population, causing pain, stiffness, and tenderness of the muscles. Upon accurate diagnostic, nonpharmacological and pharmacological therapies can be used to alleviate pain and manage other symptoms. However, lack of objective, universal applicable diagnostic criteria as well as vague and diffused symptoms, have made diagnosis difficult. In this context, our findings can shed light on potential value of CSF proteome for objectively diagnosing FM.