title: Evaluation of cytokines, oxidative stress markers and brain-derived neurotrophic factor in patients with fibromyalgia - A controlled cross-sectional study.
abstract: Previous studies measuring serum levels of biomarkers of inflammation/oxidative stress and neurotrophins levels in fibromyalgia (FM) have rendered inconsistent results. In the present study, our aim was to explore the levels of interleukins, oxidative stress markers and brain-derived neurotrophic factor (BDNF) in patients with FM in relation to depression and severity of disease.
  
  
  
  In a prospective controlled cross-sectional study, serum concentrations of IL-6, IL-8, IL-10, TNF-α, thiobarbituric acid reactive substances (TBARS), protein carbonyl and BDNF were measured in 69 FM patients and 61 healthy controls (all women). In the FM group, the Fibromyalgia Impact Questionnaire (FIQ), the Beck Depression Inventory (BDI) and the Hamilton Depression Rating Scale (HDRS) were applied. Mann Whitney's and Spearman correlation tests were used for statistical analysis.
  
  
  
  The FM patients demonstrated a significant impact of the disease on quality of life (FIQ 70.2±17.8) and most of them had depression at some level (82.6% and 87.0% as assessed by BDI and HDRS, respectively). Most biomarkers (IL-6, IL-8, TNF-α, TBARS and protein carbonyl) and BDNF did not differ significantly between patients and controls, but the IL-10 levels were higher in FM patients (adjusted p=0.041). Among FM patients, there was no correlation of HDRS, FIQ, and BDI scores with any biomarker tested here.
  
  
  
  We observed no significant differences in biomarkers between FM patients and controls, except for higher levels of IL-10 (an anti-inflammatory cytokine) in patients. The levels of biomarkers were not correlated with parameters of disease and depression severity.
authors.affiliation: Division of Rheumatology at the Hospital de Clínicas de Porto Alegre, Universidade Federal do Rio Grande do Sul, Ramiro Barcelos 2350 sala 645, 90035-003 Porto Alegre, RS, Brazil; Division of Rheumatology at the Hospital das Clínicas da Universidade Federal de Pernambuco, Prof. Moraes Rêgo, 1235, 50670-901 Recife, PE, Brazil. Electronic address: aliranzolin@hotmail.com.
authors.forename: Aline
authors.initials: A
authors.lastname: Ranzolin
authors.affiliation: Division of Rheumatology at the Hospital das Clínicas da Universidade Federal de Pernambuco, Prof. Moraes Rêgo, 1235, 50670-901 Recife, PE, Brazil.
authors.forename: Angela Luzia Branco Pinto
authors.initials: AL
authors.lastname: Duarte
authors.affiliation: Division of Rheumatology at the Hospital Nossa Senhora da Conceição - Grupo Hospitalar Conceição, Av. Francisco Trein, 596, room 2048, 91350-200 Porto Alegre, RS, Brazil.
authors.forename: Markus
authors.initials: M
authors.lastname: Bredemeier
authors.affiliation: Division of Rheumatology at the Hospital das Clínicas da Universidade Federal de Pernambuco, Prof. Moraes Rêgo, 1235, 50670-901 Recife, PE, Brazil.
authors.forename: Cláudio Antônio
authors.initials: CA
authors.lastname: da Costa Neto
authors.affiliation: Bipolar Disorders Program and INCT Translational Medicine, Hospital de Clínicas de Porto Alegre, Universidade Federal do Rio Grande do Sul, Ramiro Barcelos 2350, 90035-003 Porto Alegre, RS, Brazil.
authors.forename: Bruna Maria
authors.initials: BM
authors.lastname: Ascoli
authors.affiliation: Bipolar Disorders Program and INCT Translational Medicine, Hospital de Clínicas de Porto Alegre, Universidade Federal do Rio Grande do Sul, Ramiro Barcelos 2350, 90035-003 Porto Alegre, RS, Brazil.
authors.forename: Bianca
authors.initials: B
authors.lastname: Wollenhaupt-Aguiar
authors.affiliation: Bipolar Disorders Program and INCT Translational Medicine, Hospital de Clínicas de Porto Alegre, Universidade Federal do Rio Grande do Sul, Ramiro Barcelos 2350, 90035-003 Porto Alegre, RS, Brazil.
authors.forename: Flávio
authors.initials: F
authors.lastname: Kapczinski
authors.affiliation: Division of Rheumatology at the Hospital de Clínicas de Porto Alegre, Universidade Federal do Rio Grande do Sul, Ramiro Barcelos 2350 sala 645, 90035-003 Porto Alegre, RS, Brazil.
authors.forename: Ricardo Machado
authors.initials: RM
authors.lastname: Xavier
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000097:blood*; D019208:Brain-Derived Neurotrophic Factor / Q000378:metabolism*; D016022:Case-Control Studies; D003430:Cross-Sectional Studies; D005260:Female; D005356:Fibromyalgia / Q000097:blood* / Q000378:metabolism*; D006801:Humans; D007249:Inflammation / Q000097:blood / Q000378:metabolism; D007378:Interleukins / Q000097:blood*; D018384:Oxidative Stress / Q000502:physiology*; D011446:Prospective Studies; D011569:Psychiatric Status Rating Scales; D011788:Quality of Life; D017392:Thiobarbituric Acid Reactive Substances / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000097:blood
chemical_list: D015415:Biomarkers; D019208:Brain-Derived Neurotrophic Factor; D007378:Interleukins; D017392:Thiobarbituric Acid Reactive Substances; D014409:Tumor Necrosis Factor-alpha; C579455:BDNF protein, human
keywords: BDNF; Depression; Fibromyalgia; Interleukins; Oxidative stress