title: Association of biomarkers with health-related quality of life and history of stressors in myalgic encephalomyelitis/chronic fatigue syndrome patients.
abstract: Myalgic encephalomyelitis chronic fatigue syndrome (ME/CFS) is a common debilitating disorder associated with an intense fatigue, a reduced physical activity, and an impaired quality of life. There are no established biological markerof the syndrome. The etiology is unknown and its pathogenesis appears to be multifactorial. Various stressors, including intense physical activity, severe infection, and emotional stress are reported in the medical history of ME/CFS patients which raises the question whether any physiological and biological abnormalities usually found in these patients could be indicative of the etiology and/or the quality-of-life impairment.
  
  
  
  Thirty-six patients and 11 age-matched healthy controls were recruited. The following variables that appear to address common symptoms of ME/CFS were studied here: (1) muscle fatigue during exercise has been investigated by monitoring the compound muscle action potential (M-wave); (2) the excessive oxidative stress response to exercise was measured via two plasma markers (thiobarbituric acid reactive substances: TBARS; reduced ascorbic-acid: RAA); (3) a potential inflammatory component was addressed via expression of CD26 on peripheral blood mononuclear cells; (4) quality-of-life impairment was assessed using the London Handicap Scale (LHS) and the Medical Outcome Study Short Form-36 (SF-36). The medical history of each patient, including the presence of stressors such as intense sports practice, severe acute infection and/or severe emotional stress was documented.
  
  
  
  We observed that: (1) there were striking differences between cases and controls with regard to three biological variables: post-exercise M-wave, TBARS variations and CD26-expression at rest; (2) each of these three variables correlated with the other two; (3) abnormalities in the biomarkers associated with health-related quality of life: the LHS score was negatively correlated with the exercise-induced TBARS increase and positively correlated with CD26-expression while the pain component of SF-36 was negatively correlated with CD26-expression; (4) the TBARS increase and the M-wave decrease were the highest, and the CD26-expression level the lowest in patients who had been submitted to infectious stressors.
  
  
  
  In ME/CFS patients, severe alterations of the muscle excitability, the redox status, as well as the CD26-expression level are correlated with a marked impairment of the quality-of-life. They are particularly significant when infectious stressors are reported in the medical history.
authors: DS-ACI UMR MD2, Faculty of Medicine, Aix-Marseille University, Bd. Pierre Dramard, 13916, Marseille Cedex 20, France.|CNRS, Institut des Sciences Biologiques, Marseille, France.
authors: Emmanuel
authors: E
authors: Fenouillet
authors: Clinical Respiratory Physiology Laboratory, Nord Hospital, Marseille, France.
authors: Aude
authors: A
authors: Vigouroux
authors: DS-ACI UMR MD2, Faculty of Medicine, Aix-Marseille University, Bd. Pierre Dramard, 13916, Marseille Cedex 20, France.
authors: Jean Guillaume
authors: JG
authors: Steinberg
authors: Emergency Unit, Nord Hospital, Marseille, France.
authors: Alexandre
authors: A
authors: Chagvardieff
authors: Internal Medicine Department, European Hospital, Marseille, France.
authors: Frédérique
authors: F
authors: Retornaz
authors: DS-ACI UMR MD2, Faculty of Medicine, Aix-Marseille University, Bd. Pierre Dramard, 13916, Marseille Cedex 20, France.
authors: Regis
authors: R
authors: Guieu
authors: DS-ACI UMR MD2, Faculty of Medicine, Aix-Marseille University, Bd. Pierre Dramard, 13916, Marseille Cedex 20, France. yves.jammes@univ-amu.fr.|Clinical Respiratory Physiology Laboratory, Nord Hospital, Marseille, France. yves.jammes@univ-amu.fr.
authors: Yves
authors: Y
authors: Jammes
mesh_terms: D000200:Action Potentials; D000328:Adult; D015415:Biomarkers / Q000097:blood*; D016022:Case-Control Studies; D018819:Dipeptidyl Peptidase 4 / Q000378:metabolism; D015673:Fatigue Syndrome, Chronic / Q000097:blood* / Q000150:complications*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009132:Muscles / Q000473:pathology / Q000503:physiopathology; D010084:Oxidation-Reduction; D018384:Oxidative Stress; D010101:Oxygen Consumption; D011788:Quality of Life; D012146:Rest; D013315:Stress, Psychological / Q000097:blood* / Q000150:complications*; D017392:Thiobarbituric Acid Reactive Substances / Q000378:metabolism
chemical_list: D015415:Biomarkers; D017392:Thiobarbituric Acid Reactive Substances; D018819:Dipeptidyl Peptidase 4
keywords: CD26; Muscle excitability; Myalgic encephalomyelitis/chronic fatigue syndrome; Oxidative stress; Quality of life