Case Report Mitochondrial dysfunction in skin biopsies and blood mononuclear cells from two cases of fibromyalgia patients Mario D. Cordero a,b, ⁎, Ana M. Moreno-Fernández b , María I. Carmona-López b , José Antonio Sánchez-Alcázar a , Ana Fernández Rodríguez b , Plácido Navas a , Manuel de Miguel b a Centro Andaluz de Biología del Desarrollo, CABD, Universidad Pablo de Olavide-CSIC and Centro de Investigación Biomédica en Red de Enfermedades Raras, CIBERER, ISCIII, Sevilla, Spain b Dpto. Citología e Histología Normal y Patológica, Facultad de Medicina. Universidad de Sevilla. 41009 Sevilla, Spain abstract article info Article history: Received 29 May 2010 Received in revised form 13 June 2010 Accepted 21 June 2010 Available online xxxx Keywords: Fibromyalgia Blood mononuclear cells Skin Coenzyme Q10 Oxidative stress Mitochondrial dysfunction Objectives: Coenzyme Q 10 (CoQ 10 ) is an essential electron carrier in the mitochondrial respiratory chain and a strong antioxidant. Signs associated with skin alteration and mitochondrial dysfunction have been observed in patients with fibromyalgia (FM). The aim of this study was to analyze CoQ 10 levels, mitochondrial dysfunction, and oxidative stress in plasma, blood mononuclear cells, and skin biopsies from FM patients. Methods: We studied CoQ 10 level by HPLC in plasma, blood mononuclear cells, and skin obtained from patients with FM and healthy control subjects. Oxidative stress markers and mitochondrial respiratory chain enzyme activities were analysed in both plasma, blood mononuclear cells, and skin biopsies from FM patients. Results: Oxidative stress, mitochondrial dysfunction, and CoQ 10 deficiency have been observed in blood mononuclear cells and skin biopsies. Conclusions: In our patients, mitochondrial dysfunction and CoQ 10 deficiency are present in several tissues. These results may contribute to the understanding of the pathophysiology of FM, and, moreover, CoQ 10 deficiency could represent a good marker for the diagnosis of FM. © 2010 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved. Introduction In FM patients, some abnormalities can be observed in the periphery. Biopsies of muscle have demonstrated inflammatory markers, higher incidence of ragged red fibers, and defects of cytochrome-c-oxidase (complex IV of oxidative phosphorylation) [1]. On the other hand, unusual patterns of unmyelinated nerve fibers, as well as associated Schwann cells, have been observed in skin biopsies [2]. In some diseases with muscular alteration, coenzyme Q10 (CoQ10) deficiency has been demonstrated as a primary or secondary event [3]. Recently, we have demonstrated mitochondrial dysfunc- tion, oxidative stress, and CoQ10 deficiency in blood mononuclear cells (BMCs) of FM patients [4]. In this study, in order to elucidate whether mitochondrial disturbance was involved in the pathophysiology of FM, we analyzed mitochondrial dysfunction in BMCs, plasma, and skin biopsies from two cases of FM patients. Cases reports The study was performed with the informed consent of all participants and the approval of the local ethical committee. Patients, two women of 44 and 66 years old respectively, were diagnosed with fibromyalgia by exclusion of other diseases and syndromes, and in accordance with the American College of Rheumatology criteria. They had daily episodes of intense musculoskeletal pain and stiffness, anxiety, migraine, and sleep disturbance, and suffered depression. Characteristic findings of both FM patients and control individuals are represented in Table 1. The duration of disease was 4 years in Patient 1 and 11 years in Patient 2. Routine laboratory test yield normal results (data not show). The Visual Analogue Scale of pain (VAS), and Fibromyalgia Impact Questionnaire (FIQ) were 6 and 8, and 62 and 69, respectively (Table 1). After informed consents were signed, BMCs from heparinised blood and skin biopsies from non-tender left deltoid region of patients and healthy age- and sex-matched control subjects were obtained. CoQ 10 contents were analyzed by HPLC with ultraviolet detection according to the method of Montero et al. [5]. Lipid peroxidation (LP) was analyzed using a commercial kit from Cayman Chemical (Ann Arbor, Michigan). Measurements of respiratory chain enzymes activities were performed in skin as described [5]. BMCs were prepared by standard protocols and observed on a Philips CM-10 Clinical Biochemistry xxx (2010) xxx–xxx ⁎ Corresponding author. Centro Andaluz de Biología del Desarrollo, Universidad Pablo de Olavide-CSIC, Carretera de Utrera Km 1, Sevilla 41013, Spain. Fax: + 34 954349376. E-mail address: mdcormor@upo.es (M.D. Cordero). CLB-07421; No. of pages: 3; 4C: 0009-9120/$ – see front matter © 2010 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved. doi:10.1016/j.clinbiochem.2010.06.013 Contents lists available at ScienceDirect Clinical Biochemistry journal homepage: www.elsevier.com/locate/clinbiochem Please cite this article as: Cordero MD, et al, Mitochondrial dysfunction in skin biopsies and blood mononuclear cells from two cases of fibromyalgia patients, Clin Biochem (2010), doi:10.1016/j.clinbiochem.2010.06.013