title: Synaptophysin is an autoantigen in paraneoplastic neuropathy.
abstract: Paraneoplastic neurological syndromes (PNS) are often associated with antineuronal autoantibodies and many of them could be identified in the recent years. However, there are still new antineuronal binding patterns with yet unidentified autoantigens. We here describe a new autoantibody associated with paraneoplastic sensorimotor and autonomic neuropathy in a patient with small cell lung cancer. In indirect immunofluorescence test, the patient's serum colocalised with the synaptic protein synaptophysin in the cerebellum and myenteric plexus of the gut. Immunoblotting showed a 38 kDa reactivity, which is also the molecular weight of synaptophysin. Therefore a Western Blot with recombinant synaptophysin has been used and revealed reactivity of the serum against synaptophysin. In patients with non-paraneoplastic neuropathies or healthy controls, anti-synaptophysin autoantibodies were not detectable. In 20 SCLC patients without neurological syndromes, two patients had low-titer anti-synaptophysin autoantibodies. The patient's serum and IgG fraction showed cytotoxicity to primary cultured myenteric plexus neurons. We conclude that synaptophysin is an autoantigen in paraneoplastic neurological syndromes.
authors.affiliation: Department of Neurology, Justus-Liebig University Giessen, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Tschernatsch
authors.forename: M
authors.initials: M
authors.lastname: Klotz
authors.forename: C
authors.initials: C
authors.lastname: Probst
authors.forename: J
authors.initials: J
authors.lastname: Hosch
authors.forename: F
authors.initials: F
authors.lastname: Valtorta
authors.forename: M
authors.initials: M
authors.lastname: Diener
authors.forename: T
authors.initials: T
authors.lastname: Gerriets
authors.forename: M
authors.initials: M
authors.lastname: Kaps
authors.forename: K H
authors.initials: KH
authors.lastname: Schäfer
authors.forename: F
authors.initials: F
authors.lastname: Blaes
mesh_terms: D000818:Animals; D000920:Antibody-Dependent Cell Cytotoxicity; D001323:Autoantibodies / Q000378:metabolism / Q000633:toxicity; D001324:Autoantigens / Q000276:immunology* / Q000378:metabolism; D015153:Blotting, Western; D016923:Cell Death / Q000276:immunology; D045744:Cell Line, Tumor; D003601:Cytotoxicity Tests, Immunologic; D019084:Fluorescent Antibody Technique, Indirect; D006801:Humans; D007074:Immunoglobulin G / Q000633:toxicity; D008297:Male; D008875:Middle Aged; D009197:Myenteric Plexus / Q000166:cytology / Q000276:immunology; D009474:Neurons / Q000166:cytology / Q000276:immunology; D020364:Paraneoplastic Polyneuropathy / Q000175:diagnosis / Q000276:immunology*; D051381:Rats; D017208:Rats, Wistar; D016708:Synaptophysin / Q000276:immunology* / Q000378:metabolism
chemical_list: D001323:Autoantibodies; D001324:Autoantigens; D007074:Immunoglobulin G; D016708:Synaptophysin