title: Anti-aquaporin-4 autoantibodies in systemic lupus erythematosus persist for years and induce astrocytic cytotoxicity but not CNS disease.
abstract: Anti-aquaporin-4 autoantibodies are specific for the neuromyelitis optica spectrum disorders (NMOSD) and they have also been described in patients with systemic lupus erythematosus (SLE) with neurological signs consistent with NMOSD. Our objective was to test for the presence and pathogenicity of anti-AQP4 antibodies in SLE patients without neurological disease. Sera from 89 non-CNS-SLE patients were screened for anti-AQP4 autoantibodies. Two of the 89 patients were positive. Archived samples dating back 11 years were also positive. A brain and spinal cord MRI did not reveal any NMOSD-compatible lesions. An in vitro cytotoxicity assay showed that either sera or purified IgG from these patients induced a complement-mediated damage in cultured astrocytes comparable to antibodies obtained from typical NMO patients. We conclude that AQP4-antibodies can be present in SLE patients and persist for many years, without concurrent clinical or radiological NMOSD signs. It is unclear why the anti-AQP4 antibodies did not induce CNS disease.
authors.affiliation: Neuroimmunology Unit, Department of Pathophysiology, Faculty of Medicine, National and Kapodistrian University of Athens, Athens, Greece.
authors.forename: Harry
authors.initials: H
authors.lastname: Alexopoulos
authors.affiliation: Neuroimmunology Unit, Department of Pathophysiology, Faculty of Medicine, National and Kapodistrian University of Athens, Athens, Greece.
authors.forename: Eleni I
authors.initials: EI
authors.lastname: Kampylafka
authors.affiliation: Neuroimmunology Unit, Department of Pathophysiology, Faculty of Medicine, National and Kapodistrian University of Athens, Athens, Greece; Center for Basic Research, Biomedical Research Foundation of the Academy of Athens, Athens, Greece.
authors.forename: Penelope
authors.initials: P
authors.lastname: Fouka
authors.affiliation: Neuroimmunology Unit, Department of Pathophysiology, Faculty of Medicine, National and Kapodistrian University of Athens, Athens, Greece.
authors.forename: Ioanna
authors.initials: I
authors.lastname: Tatouli
authors.affiliation: Neuroimmunology Unit, Department of Pathophysiology, Faculty of Medicine, National and Kapodistrian University of Athens, Athens, Greece.
authors.forename: Sofia
authors.initials: S
authors.lastname: Akrivou
authors.affiliation: Center for Basic Research, Biomedical Research Foundation of the Academy of Athens, Athens, Greece.
authors.forename: Panagiotis K
authors.initials: PK
authors.lastname: Politis
authors.affiliation: Neuroimmunology Unit, Department of Pathophysiology, Faculty of Medicine, National and Kapodistrian University of Athens, Athens, Greece.
authors.forename: Haralampos M
authors.initials: HM
authors.lastname: Moutsopoulos
authors.affiliation: Neuroimmunology Unit, Department of Pathophysiology, Faculty of Medicine, National and Kapodistrian University of Athens, Athens, Greece.
authors.forename: Athanasios G
authors.initials: AG
authors.lastname: Tzioufas
authors.affiliation: Neuroimmunology Unit, Department of Pathophysiology, Faculty of Medicine, National and Kapodistrian University of Athens, Athens, Greece; Department of Neurology, Thomas Jefferson University, Philadelphia, PA, USA. Electronic address: mdalakas@med.uoa.gr.
authors.forename: Marinos C
authors.initials: MC
authors.lastname: Dalakas
mesh_terms: D051401:Aquaporin 4 / Q000276:immunology*; D001253:Astrocytes / Q000187:drug effects*; D001323:Autoantibodies / Q000097:blood* / Q000633:toxicity*; D005260:Female; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D057809:HEK293 Cells; D006801:Humans; D008180:Lupus Erythematosus, Systemic / Q000097:blood* / Q000276:immunology / Q000473:pathology*; D008297:Male; D018709:Statistics, Nonparametric; D014162:Transfection
chemical_list: C496030:AQP4 protein, human; D051401:Aquaporin 4; D001323:Autoantibodies; C485184:enhanced green fluorescent protein; D049452:Green Fluorescent Proteins
keywords: AQP4; Astrocytes; Autoantibodies; Neuromyelitis optica; Systemic lupus erythematosus