International Journal of Neuroscience, 2013; 123(8): 557–562 Copyright © 2013 Informa Healthcare USA, Inc. ISSN: 0020-7454 print / 1543-5245 online DOI: 10.3109/00207454.2013.782025 RESEARCH ARTICLE Serum anti-neuronal antibodies in amyotrophic lateral sclerosis Arzu C ¸ oban, 1 Canan Ulusoy, 2 Murat Giris ¸, 2 Selin Turan, 2 Recai T ¨ urko˘ glu, 3 Erdem T ¨ uz¨ un, 2 and Halil Atilla ˙ Idriso˘ glu 1 1 Department of Neurology, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Turkey; 2 Department of Neuroscience, Institute for Experimental Medical Research (DETAE), Istanbul University, Istanbul, Turkey; 3 Department of Neurology, Haydarpasa Numune Education and Research Hospital, Istanbul, Turkey We aimed to investigate various anti-neuronal antibodies in sera of amyotrophic lateral sclerosis (ALS) patients to detect possible autoimmune encephalitis patients imitating ALS indings and to delineate the validity of routine screening of well-characterized anti-neuronal antibodies in ALS. The patients fulilling the revised El Escorial diagnostic criteria for deinite ALS were included. Their serum samples were investigated for antiganglioside (IgM/IgG) and onconeural (IgG) antibodies by immunoblotting, for ion channel antibodies (IgG) by a cell-based assay and for IgG binding patterns to the rat brain by indirect immunohistochemistry. Thirty-ive patients with deinite ALS and 30 healthy individuals were included. Ganglioside antibodies were detected in 2 out of 35 (5.7%) patients with ALS. The onconeural and ion channel antibodies were negative in our series. Varied serum IgG binding patterns were identiied in eight (22.9%) patients. Although autoimmune encephalitis patients may occasionally present with atypical motor neuron disease indings, deinite ALS patients do not appear to exhibit onconeural or ion channel antibodies, suggesting that routine analysis of these antibodies in typical ALS is not mandatory. By contrast, some ALS patients display anti-neuronal antibodies against undetermined target antigens, prompting investigation of these novel antibodies with more advanced methods. KEYWORDS: amyotrophic lateral sclerosis, anti-neuronal antibodies, serum Introduction Amyotrophic lateral sclerosis (ALS) is a form of motor neuron disease (MND) of unknown etiology that pri- marily affects upper and lower motor neurons [1]. The immunological abnormalities have been implicated in the pathogenesis of ALS [2–4] based on, among other factors, the presence of serum anti-neuronal antibodies that interact with motor neuron antigens [2,5–9]. Also, in ALS and non-ALS MND patients, previous studies have identiied various anti-neuronal antibodies, includ- ing so-called well-characterized antibodies strictly asso- ciated with paraneoplastic disorders and autoimmune encephalitis [2,4,5,10–20]. The aim of our study was to evaluate various anti-neuronal antibodies in serum Received 6 November 2012; revised 4 February 2013; accepted 27 February 2013. Correspondence: Arzu C ¸ oban, Department of Neurology, Istanbul Faculty of Medicine, Istanbul University, Millet cad. Capa 34390, Istanbul, Turkey. Fax: + 90 212 4142000. Tel: + 90 212 5334393. E-mail: arzucoban2002@yahoo.com samples of ALS patients, to investigate whether deinite ALS patients might display well-characterized antibod- ies associated with autoimmune encephalitis and to de- tect possible autoimmune encephalitis masquerading as idiopathic ALS. Methods Patients Clinically deinite ALS patients (n = 35) and a control group of healthy individuals (n = 30) were included. The diagnosis of deinite ALS was based on the revised El Escorial criteria [21]. Our primary aim was to detect pathogenic antibodies that are expected to develop in the earlier stages of ALS, rather than antibodies that emerge in the advanced stages of disease as a bystander effect of extensive neuronal loss. Also, anti-neuronal antibodies might plausibly cease to exist in the advanced stages of neurodegeneration due to excessive loss of spinal cord neurons. To avoid the interference of these factors, we only included patients with ≤6 months of 557 Int J Neurosci Downloaded from informahealthcare.com by Dr. Erdem Tüzün on 07/18/13 For personal use only.