Do Routine Laboratory Parameters have Predictive Ability to Differentiate Subjects with Fibromyalgia from Healthy Subjects?

The aim of this study was to evaluate laboratory parameters for investigating their potential predictive ability to differentiate patients with fibromyalgia (FM) from healthy subjects. We carried out a case-control study with 79 FM patients and 20 controls to analyze complete blood count, serum chemistry profile, glycosylated hemoglobin (HbA1c), and erythrocyte sedimentation rate (ESR). The predictive value of these parameters was determined by receiver operating characteristic (ROC) analysis. We also examined the relationships with clinical parameters (functional capacity, pain, and physical and mental health status). Results showed significant differences in red blood cell count, hematocrit, mean corpuscular hemoglobin concentration, platelet count, creatinine, HbA1c, and ESR between groups. According to ROC analysis, all these parameters may assist in making FM diagnosis. Hematocrit and ESR values were correlated with FM clinical parameters. The determination of these routine laboratory parameters may be an uncomplicated means of facilitating FM diagnosis, together with the clinical data of the patient.

Insight into the biological pathways underlying fibromyalgia by a proteomic approach.

Fibromyalgia (FM) is a form of non-articular rheumatism difficult to diagnose and treat because its etiology remains still elusive. Proteomics makes possible the systematic analysis of hundreds of proteins in clinical samples. Consequently, it has become a key tool for finding altered molecular pathways in different diseases. In this context, the present study analyzes changes in the plasma proteome of patients with FM by nanoscale liquid chromatography coupled to tandem mass spectrometry. Deregulated proteins were studied using Ingenuity Pathways Analysis (IPA) and Kyoto Encyclopedia of Genes and Genomes. Conventional analytical methods were used to validate selected proteins. We found a total of 33 proteins differentially expressed in patients with FM. Haptoglobin and fibrinogen showed the highest FM/control ratio. IPA analysis revealed that the top enriched canonical pathways were acute-phase response signaling, Liver-X Receptor/Retinoid-X Receptor activation, Farnesoid-X Receptor/Retinoid-X Receptor activation, and coagulation and complement systems. The importance of inflammation in FM was corroborated by the increase in erythrocyte sedimentation rate. In conclusion, our results support the existence of a plasma protein signature of FM that involves different biological pathways all of them related to inflammation, and point to haptoglobin and fibrinogen as plausible biomarker-candidates for future studies. SIGNIFICANCE: The etiology of fibromyalgia (FM) remains elusive making its diagnosis and treatment difficult. The characterization of the proteome signature of this syndrome will improve its understanding. However, to date proteomic analyses in FM are scarce. The goal of the present work is to analyse, for the first time, changes in plasma protein profiles of patients with FM in comparison to control subjects, using label free relative protein quantification by nanoscale liquid chromatography coupled to tandem mass spectrometry. Our data demonstrate the existence of a common protein signature in the plasma of patients with FM that could explain some of the symptoms associated to this syndrome. The analysis of the 33 proteins differentially expressed corroborates the crucial role of inflammation in the pathogenesis of this syndrome. The interplay of the complement and coagulation cascades contributes to the inflammatory process, while the activation of Liver-X Receptor/Retinoid-X Receptor and Farnesoid-X Receptor/Retinoid-X Receptor could attempt to alleviate it. Finally, we have identified two proteins, haptoglobin and fibrinogen, as potential biomarker-candidates of FM for future studies.

Nitric Oxide, Inflammation, Lipid Profile, and Cortisol in Normal- and Overweight Women With Fibromyalgia.

OBJECTIVES: Research has identified many factors associated with fibromyalgia (FM), but findings have been inconsistent. This study aimed to investigate changes in levels of nitric oxide (NO), inflammatory markers, lipid profile, and cortisol in normal- and overweight patients with FM and controls. Since most patients with FM are overweight, we explored possible changes in these markers according to body mass index (BMI). METHODS: This preliminary study was performed on serum samples of women with FM and age-matched controls, grouped according to their BMI: 12 normal-weight patients and 12 controls and 13 overweight patients and 8 controls. Ozone-based chemiluminescence assay was used to measure NO. Inflammatory mediators and cortisol were determined by immunoassay. Lipid profile was measured by a spectrophotometric procedure. Functional capacity was assessed by the fibromyalgia impact questionnaire (FIQ). RESULTS: Normal-weight patients showed higher levels of C-reactive protein (CRP) and apolipoprotein B compared to controls (both p < .05). CRP, apolipoprotein B, and triglycerides were higher in overweight patients versus overweight controls (all p < .05) and in overweight versus normal-weight patients (CRP p < .01; apolipoprotein B, triglycerides p < .05). The other markers were unaffected. Apolipoprotein B (r = .762; p < .05) and NO (r = -.921; p < .05) levels correlated with FIQ score in normal-weight patients. CRP level correlated with FIQ (r = .912; p < .05) in overweight patients. CONCLUSIONS: CRP and apolipoprotein B, biomarkers linked to cardiovascular events, may be associated with FM-related dysfunction in normal- and overweight women with FM. Their increased levels in these patients may indicate an increased risk of cardiovascular disease.