title: Investigation of neuronal auto-antibodies in systemic lupus erythematosus patients with epilepsy.
abstract: Epilepsy is an important feature for neuropsychiatric involvement in systemic lupus erythematosus (SLE) with unknown mechanism. Our aim was to investigate the presence of neuronal auto-antibodies (NAbs) in neuropsychiatric SLE (NPSLE).
  
  
  
  Eighteen SLE patients (17 females, 1 male) experiencing recurrent seizures were enrolled to this study. Their clinical characteristics, EEG and MRI findings and follow-up information were evaluated from their files. Antibodies against voltage-gated potassium channel (VGKC)-complex antigens, contactin-associated protein-like 2 (CASPR-2), leucine-rich, glioma inactivated 1 (LGI1), glutamic acid decarboxylase (GAD), N-methyl-d-aspartate receptor (NMDA-R), alpha-amino-3-hydroxy-5-methyl-4-isoxazoleproprionic acid receptor (AMPA-R) and type B gamma aminobutyric acid receptors (GABAB-R) were screened in the sera of these patients. Moreover, indirect immunohistochemistry and immunocytochemistry tests were performed to reveal neuropil antibodies.
  
  
  
  Six out of 18 patients (33.3%) had various forms of NAbs. Among them, one patient had antibodies against GAD, one patient with hippocampal sclerosis on MRI was CASPR-2 antibody positive, whereas the remaining four patients showed hippocampal neuropil staining. We could not find a significant difference between seropositive and seronegative groups, regarding the clinical characteristics, EEG and MRI findings.
  
  
  
  This study is the first to show hippocampal neuronal staining (4/18) reflecting antibodies against unknown neuronal cell surface antigens in SLE patients with epilepsy, besides the rare occurrence of GAD and CASPR2 antibodies. Further prospective studies are needed to search for new NAbs and uncover their pathogenic role in SLE associated with epilepsy.
authors.affiliation: Department of Neurology, Istanbul University, Istanbul Faculty of Medicine, Istanbul, Turkey. Electronic address: zkaraaslan@gmail.com.
authors.forename: Zerrin
authors.initials: Z
authors.lastname: Karaaslan
authors.affiliation: Department of Neurology, Istanbul University, Istanbul Faculty of Medicine, Istanbul, Turkey. Electronic address: esmeekizoglu@yahoo.com.
authors.forename: Esme
authors.initials: E
authors.lastname: Ekizoğlu
authors.affiliation: Department of Neurology, Istanbul University, Istanbul Faculty of Medicine, Istanbul, Turkey. Electronic address: pinartopaloglu2000@yahoo.com.
authors.forename: Pınar
authors.initials: P
authors.lastname: Tektürk
authors.affiliation: Department of Neuroscience, Istanbul University, Institute of Experimental Medicine, Istanbul, Turkey. Electronic address: eceerdag@gmail.com.
authors.forename: Ece
authors.initials: E
authors.lastname: Erdağ
authors.affiliation: Department of Neuroscience, Istanbul University, Institute of Experimental Medicine, Istanbul, Turkey. Electronic address: drerdem@yahoo.com.
authors.forename: Erdem
authors.initials: E
authors.lastname: Tüzün
authors.affiliation: Department of Neurology, Istanbul University, Istanbul Faculty of Medicine, Istanbul, Turkey. Electronic address: nersesb@yahoo.com.
authors.forename: Nerses
authors.initials: N
authors.lastname: Bebek
authors.affiliation: Department of Neurology, Istanbul University, Istanbul Faculty of Medicine, Istanbul, Turkey. Electronic address: candangrss@gmail.com.
authors.forename: Candan
authors.initials: C
authors.lastname: Gürses
authors.affiliation: Department of Neurology, Istanbul University, Istanbul Faculty of Medicine, Istanbul, Turkey. Electronic address: baykanb@istanbul.edu.tr.
authors.forename: Betül
authors.initials: B
authors.lastname: Baykan
mesh_terms: D000328:Adult; D000818:Animals; D001323:Autoantibodies / Q000097:blood*; D015415:Biomarkers / Q000097:blood; D001921:Brain / Q000000981:diagnostic imaging / Q000276:immunology / Q000473:pathology; D002478:Cells, Cultured; D004827:Epilepsy / Q000097:blood / Q000150:complications* / Q000276:immunology* / Q000473:pathology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007150:Immunohistochemistry; D008180:Lupus Erythematosus, Systemic / Q000097:blood / Q000150:complications* / Q000000981:diagnostic imaging / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D009474:Neurons / Q000276:immunology / Q000473:pathology; D051381:Rats; D012189:Retrospective Studies
chemical_list: D001323:Autoantibodies; D015415:Biomarkers
keywords: Epilepsy; Hippocampal neuropil; Neuronal auto-antibodies; Systemic lupus erythematosus