Clinical Short Communication Evaluation of total, ceruloplasmin-associated and type II ferroxidase activities in serum and cerebrospinal fluid of multiple sclerosis patients Alessandro Trentini a,1 , Massimiliano Castellazzi a,1 , Arianna Romani a , Monica Squerzanti a , Eleonora Baldi b , Maria Luisa Caniatti b , Maura Pugliatti a , Enrico Granieri a , Enrico Fainardi c , Tiziana Bellini a, ⁎, Carlo Cervellati a a Department of Biomedical and Specialist Surgical Sciences, University of Ferrara, 44121 Ferrara, Italy b Neurology Unit, Department of Neurosciences and Rehabilitation, Azienda Ospedaliera-Universitaria, Arcispedale S. Anna, 44124 Ferrara, Italy c Unit of Neuroradiology, Careggi University Hospital, Firenze, Italy abstract article info Article history: Received 27 January 2017 Received in revised form 21 March 2017 Accepted 11 April 2017 Available online xxxx Multiple sclerosis (MS) patients have increased brain iron deposition with higher oxidative stress (OxS). These two features can be caused by an inefficient removal of free iron from extracellular compartment. Ferroxidase ac- tivity (Feox) exerted by ceruloplasmin (FeoxCp) and by other molecules (FeoxII) appears to have a central role in this process. The aim of this study was to investigate serum and cerebrospinal fluid (CSF) total Feox, FeoxII and FeoxCp activities in MS patients and neurological controls. Serum and CSF Feox activity, FeoxII and FeoxCp activ- ity was measured in 91 relapsing-remitting (RR) MS patients, 79 subjects with other inflammatory neurological disorders (OIND) and 65 with non-inflammatory neurological disorders (NIND), as controls. This study was ap- proved by the Local Committee for Medical Ethics in Research. Serum total Feox activity was lower in MS group than in both NIND and OIND, with only the former control group differing significantly (p b 0.001); FeoxII and FeoxCp activities were comparable among the groups. Serum Feox activities were not associated with disease ac- tivity as assessed by clinical examination or by Magnetic Resonance Imaging (MRI). Only total Feox activity was detectable in the CSF and was not different in MS compared to either OIND or NIND. In conclusion, a condition of low systemic Feox may increase the susceptibility of MS patients to iron(II) mediat- ed-oxidative damage. This alteration is not reflected in CSF, suggesting that agents endowed with Feox activity might have different impact in iron homeostasis in the central nervous system compared to periphery. © 2017 Published by Elsevier B.V. Keywords: Multiple sclerosis Oxidative stress Ferroxidase activity Ceruloplasmin Serum Cerebrospinal fluid 1. Introduction Multiple sclerosis (MS) is a disease of the central nervous system (CNS) of supposed autoimmune origin [1] where neurodegeneration, axonal damage and neuroinflammation coexist [2,3]. A growing body of evidence suggests that oxidative stress (OxS) is an important deter- minant for the underlying damage in MS. Indeed, increased OxS markers (oxidized DNA, lipids, and protein adducts) have been ob- served in active lesions [4], with the simultaneous upregulation in anti- oxidant enzymatic defense [5], highlighting the importance of oxidative processes in MS pathogenesis. Oxidative damage against neurons and axons results from uncontrolled raise in reactive oxygen species (ROS) production, which in turn might stem from the abnormal iron deposits observed in the brain of MS patients [6,7]. Indeed, extremely toxic ROS such as hydroxyl radical (OH•) can be promoted by free iron(II) through the Fenton's reaction. Excessive release of this pro-oxidant metal can likely occur in MS brain from degraded myelin, where iron is normally stored bound to ferritin [6]. One mechanism of defense against this chemical source of highly toxic ROS is the spontaneous ferroxidase (Feox) activity observed in bi- ological fluids and brain interstitial space [8]. Indeed, through this activ- ity iron(II) is converted into the less toxic iron(III) promoting its final loading into transferrin, thus subtracting it from the Fenton reaction. Traditionally, Feox activity is carried out through two main mecha- nisms: i) ceruloplasmin (Cp), a copper carrier responsible for the major- ity of the ferroxidase activity observed in biological fluids (FeoxCp or FeoxI); ii) a sodium-azide insensitive activity, due to small molecules and other unknown proteins, called FeoxII [9]. Our previous pilot report [10] suggested that the decrease in system- ic total Feox activity might be a shared characteristic in inflammatory disorders of the central nervous system (CNS) including MS. In the pres- ent study, we dealt with a larger sample of MS patients and neurological controls and, for the first time, explored: 1) the contributions of FeoxCp and FeoxII on the systemic capacity of oxidizing iron; 2) Total Feox in ce- rebrospinal fluid (CSF). Journal of the Neurological Sciences 377 (2017) 133–136 ⁎ Corresponding author at: Department of Biomedical and Specialist Surgical Sciences, University of Ferrara, via Luigi Borsari 46, 44121 Ferrara, Italy. E-mail addresses: blt@unife.it, tiziana.bellini@unife.it (T. Bellini). 1 These authors contributed equally to this work. http://dx.doi.org/10.1016/j.jns.2017.04.021 0022-510X/© 2017 Published by Elsevier B.V. Contents lists available at ScienceDirect Journal of the Neurological Sciences journal homepage: www.elsevier.com/locate/jns