Ntioxidant). Thus, the effective enhancementof intracellular ROS production in ME/CFS cannot be evaluated first because it would have required muscle biopsies and second because it is counterbalanced by the intracellular antioxidants that are not explored in the present study.Conclusion In accordance with a recent report stating that severe ME/CFS StatticMedChemExpress Stattic patients differover time from moderate ME/CFS patients and express significant immune abnormalities [17], our results indicate that the simultaneous monitoring of the muscle function, redox response, and CD26expression could contribute, together with the health status scales, to identifying ME/CFS and to assessing its severity. These results may also help to distinguish ME/ CFS from fibromyalgia, because the CD26 activity on PBMC increases in fibromyalgia [19] whereas it decreases in CFS patients.Abbreviations DPP-IV: dipeptidyl peptidase-IV; EMG: electromyography; M-wave: maximal decrease in M-wave amplitude; TBARS: exercise-induced increase in TBARS level vs rest level; LHS: London Handicap Scale; ME/CFS: myalgic encephalomyelitis/chronic fatigue syndrome; MOS SF-36: Medical Outcome Study Short Form-36; M-wave: compound muscle action potentials; PBMC: peripheral blood mononuclear cells; RAA: reduced ascorbic acid; TBARS: thiobarbituric acid reactive substances; TCA: trichloracetic acid; VO2max: maximal oxygen uptake. Authors’ contributions EF, FR and YJ designed the research study, analyzed the data and wrote the paper; EF, AV, AC and JGS performed the acquisition of data; EF, FR, RG and YJ analyzed and interpreted the data. All authors read and approved the final manuscript. Author details DS-ACI UMR MD2, Faculty of Medicine, Aix-Marseille University, Bd. Pierre Dramard, 13916 Marseille Cedex 20, France. 2 CNRS, Institut des Sciences Biologiques, Marseille, France. 3 Clinical Respiratory Physiology Laboratory, Nord Hospital, Marseille, France. 4 Emergency Unit, Nord Hospital, Marseille, France. 5 Internal Medicine Department, European Hospital, Marseille, France.Acknowledgements None. Availability of data and materials The data supporting our findings can be found in our laboratory (UMR MD2 Faculty of Medicine, Marseille) where they are stored in Sigma Plot Program of our computer. Consent for publication Our manuscript does not contain any person’s data in any form (including individual details, images or videos). Ethics approval and consent to participate The protocol was approved by the Ethics Committee of our institution (CPP Sud Mediterran 1) and the study was carried out by the Code of Ethics of the World Medical Association (Declaration of Helsinki). Procedures were carried out with the adequate understanding and written consent of the PubMed ID:https://www.ncbi.nlm.nih.gov/pubmed/27532042 subjects. Competing interests The authors declare that they have no competing interests.Fenouillet et al. J Transl Med (2016) 14:Page 7 ofReceived: 9 June 2016 Accepted: 16 AugustReferences 1. Fukuda K, Straus SE, Hickie I, Sharpe MC, Dobbins JG, Komaroff A. The chronic fatigue syndrome: a comprehensive approach to its definition and study. International Chronic Fatigue Syndrome Study Group. Ann Intern Med. 1994;12:953?. 2. Institute of Medicine of the National Academies. Beyond myalgic encephalomyelitis/chronic fatigue syndrome: redefining an illness. Committee on the Diagnostic Criteria for Myalgic Encephalomyelitis/ Chronic Fatigue Syndrome; Board on the Health of Select Populations. Washington, DC: National Academies Press; 2015. www.nap-edu. htt.
