A study of oxidative stress, cytokines and glutamate in Wilson disease and their asymptomatic siblings Jayantee Kalita a, ⁎, Vijay Kumar a , Usha K. Misra a , Abhay Ranjan a , Hamidullah Khan b , Rituraj Konwar b a Department of Neurology, Sanjay Gandhi Post Graduate medical Sciences, Lucknow, India b Division of Endocrinology, CSIR-Central Drug Research Institute, Lucknow, India abstract article info Article history: Received 21 April 2014 Received in revised form 13 June 2014 Accepted 17 June 2014 Available online xxxx Keywords: Wilson disease Glutathione Lipid peroxidation Cytokine Glutamate Copper Background: Free copper in Wilson disease (WD) is toxic and may reduce antioxidant, increase oxidative stress marker and thereby cytokine release and excitotoxic injury, but there is paucity of studies in humans. We report oxidative stress markers, cytokines and glutamate in neurologic WD and correlate these with their clinical sever- ity, laboratory findings and extent of Magnetic resonance imaging (MRI) changes. Methods: 29 patients with neurologic WD and 9 asymptomatic WD siblings were included and their clinical, treatment history, disease severity, biochemical findings and MRI changes were noted. Glutathione (GSH), total antioxidant capacity (TAC) and malonodialdehyde (MDA) were measured by spectrophotometer, cytokines by cytokine bead array and glutamate by the fluorometer. Results: In WD patients, the glutathione (mean ± SEM, 2.20 ± 0.06 vs. 2.73 ± 0.04 mg/dl, P b 0.001) and TAC (1.70 ± 0.03 vs. 2.29 ± 0.02 Trolox_Eq_mmol/l, P b 0.001) were reduced, and MDA and glutamate (23.93 ± 0.54 vs. 19.96 ± 0.27 μmol/l; P b 0.001) were increased (4.7 ± 0.11 vs. 3.03 ± 0.52 nmol/ml, P b 0.001) com- pared to controls. The serum IL6 {median (IQRs), 9.42(10.92) vs. 5.2(5.34) pg/ml; P = 0.001}, IL8 {12.37(10.92) vs. 5.63(5.52) pg/ml; P b 0.001}, IL10 {8.33(8.3) vs. 2.05(1.37) pg/ml; P = 0.001} and TNFα {6.14(8.95) vs. 3.61(3.58) pg/ml; P b 0.001} were also increased in WD patients compared to controls. These changes were more marked in the neurologic WD compared to asymptomatic WD and in the untreated com- pared to treated patients. TAC correlated with duration of illness, serum free copper, 24 hour urinary copper and serum ceruloplasmin, and glutamate with MDA, TNFα, ceruloplasmin and 24-hour urinary copper. Conclusions: In WD patients, antioxidants are reduced and MDA, cytokines and glutamate are increased which are more marked in symptomatic neurologic WD than asymptomatic patients. © 2014 Published by Elsevier B.V. 1. Introduction Wilson disease (WD; OMIM #277900) is an autosomal recessive dis- ease caused by mutation in ATP7B gene spanning more than 80 kb ge- nomic DNA on chromosome 13q4.2–q21 (Thomas et al., 1995). ATP7B gene has 21 exons, encodes 1465 amino acids and its gene products help in transporting copper (Cu) into the secretary pathway for incor- poration into apoceruloplasmin and excretion into the bile (Vrabelova et al., 2005). Mutation of ATP7B gene results in impaired trafficking of Cu in and through the hepatocytes resulting in excessive accumulation of Cu in various organs such as the liver, cornea, lens and brain. In the blood, Cu is found in the bound and in the free states. In the bound state, Cu is covalently linked to ceruloplasmin, while free Cu in the blood loosely binds to albumin and other small molecules. The level of loosely bound Cu is increased in WD, although the total serum Cu and ceruloplasmin levels usually remain low (Ogihara et al., 1995). In a normal individual, free Cu is only 10–15%, which is greatly increased in WD (Chen et al., 2012). Free Cu level is highly toxic, can cross blood–brain barrier and induces oxidative damage to the brain tissue (Choi and Zheng, 2009). Since 1993, total antioxidant capacity (TAC) of a hydrophilic antioxidant is measured in biological sam- ples to learn how the human body reacts to oxidative and nitrosactive injury. TAC measures hydrophilic antioxidants and is highly influenced by serum uric acid level (Bruha et al., 2011). Glutathione (GSH) is a water-soluble antioxidant and is widely expressed in most of the organs. Free Cu level in WD increases and there is a reduction in the Journal of Neuroimmunology xxx (2014) xxx–xxx Abbreviations: ADL, activities of daily living; BFM, Burke–Fahn–Marsden; CLD, chronic liver disease; Cu, copper; EDTA, ethylene diamine tetra-acetic acid; GSH, glutathione; KF, Kayser–Fleischer; LPO, lipid peroxidation; MRI, magnetic resonance imaging; MDA, malonodialdehyde; MMSE, Mini Mental State Examination; ROS, reactive oxygen species; TAC, total antioxidant capacity; TNFα, tumor necrosis factor-alpha; IL, interleukin; WD, Wilson disease. ⁎ Corresponding author at: Department of Neurology, Sanjay Gandhi Post Graduate Institute of Medical Sciences, Raebareily Road, Lucknow 226014, India. Tel.: +91 522 2494169; fax: +91 522 2668811. E-mail addresses: jayanteek@yahoo.com, jkalita@sgpgi.ac.in (J. Kalita). JNI-475932; No of Pages 8 http://dx.doi.org/10.1016/j.jneuroim.2014.06.013 0165-5728/© 2014 Published by Elsevier B.V. Contents lists available at ScienceDirect Journal of Neuroimmunology journal homepage: www.elsevier.com/locate/jneuroim Please cite this article as: Kalita, J., et al., A study of oxidative stress, cytokines and glutamate in Wilson disease and their asymptomatic siblings, J. Neuroimmunol. (2014), http://dx.doi.org/10.1016/j.jneuroim.2014.06.013