title: Betaine homocysteine methyl transferase 1, a novel auto-antigen associated with anti-Golgi immune reactivity.
abstract: Anti-Golgi antibodies are rare autoantibodies that have been described in systemic autoimmune diseases. Not all Golgi auto-antigens are known. The objective of this study was to identify a novel auto-antigen associated with anti-Golgi immune reactivity. Sera from a patient with Golgi immune reactivity and from a control individual were used for Western blotting after 2-dimensional gel separation of a rat Golgi-enriched extract. Betaine homocysteine S-methyltransferase 1 (BHMT1) was identified as an auto-antigen by MALDI-TOF/TOF mass spectrometry. Using human recombinant BHMT1, a strong positive blotting signal was obtained with serum from the patient but not from a control. Pre-absorption of the serum sample with reactivity to BHMT1 with recombinant human BHMT1 resulted in decreased reactivity on Western blotting and in disappearance of the Golgi-like pattern on indirect immunofluorescence. Using immunocytochemistry, we confirmed the subcellular localization of BHMT1 to the Golgi apparatus. Antibodies to BHMT1 were found in four of 80 samples with a Golgi-pattern on indirect immunofluorescence. The antibodies were not associated with a specific clinical condition. We identified BHMT1 as a novel auto-antigen associated with anti-Golgi immune reactivity.
authors.affiliation: Laboratory Medicine, Immunology, University Hospitals Leuven, Leuven, Belgium.
authors.forename: Karolien
authors.initials: K
authors.lastname: Van den Bergh
authors.forename: Martine
authors.initials: M
authors.lastname: Vercammen
authors.forename: Stephan
authors.initials: S
authors.lastname: Regenass
authors.forename: Rita
authors.initials: R
authors.lastname: Derua
authors.forename: Pieter
authors.initials: P
authors.lastname: Vermeersch
authors.forename: Peter
authors.initials: P
authors.lastname: Pokreisz
authors.forename: Annick
authors.initials: A
authors.lastname: Ocmant
authors.forename: Katrijn Op
authors.initials: KO
authors.lastname: de Beéck
authors.forename: Stefan
authors.initials: S
authors.lastname: Janssens
authors.forename: Etienne
authors.initials: E
authors.lastname: Waelkens
authors.forename: Xavier
authors.initials: X
authors.lastname: Bossuyt
mesh_terms: D000818:Animals; D001324:Autoantigens / Q000276:immunology*; D050940:Betaine-Homocysteine S-Methyltransferase / Q000276:immunology*; D015153:Blotting, Western; D002460:Cell Line; D006056:Golgi Apparatus / Q000276:immunology*; D006801:Humans; D007150:Immunohistochemistry; D051381:Rats; D011994:Recombinant Proteins / Q000276:immunology
chemical_list: D001324:Autoantigens; D011994:Recombinant Proteins; D050940:Betaine-Homocysteine S-Methyltransferase