title: Glucose-6-phosphate isomerase variants play a key role in the generation of anti-GPI antibodies: possible mechanism of autoantibody production.
abstract: Glucose-6-phosphate isomerase (GPI), recognized as an autoantigen in the K/BxN arthritis model, is a ubiquitous cytoplasmic enzyme. Anti-GPI antibodies (Abs) are also detected in the serum of patients with arthritic diseases including rheumatoid arthritis (RA). So far, 24 GPI variants have been reported and most of these variants relate to non-spherocytic hemolytic disease. To understand the mechanisms of anti-GPI Ab production, cDNAs from peripheral blood mononuclear cells of subjects with or without anti-GPI Abs were cloned and sequenced. We identified 39 new GPI variants (57-1596 bp). The frequency of GPI variants in healthy control subjects (HS) with anti-GPI Abs (27/73, 31.5%) was significantly higher than that in anti-GPI Ab-negative HS (5/78, 6.4%, p < 0.001). The frequency of GPI variants in anti-GPI Ab-positive RA patients (22/77, 28.6%) was more significantly higher than in anti-GPI Ab-negative patients (1/63, 1.6%, p < 0.0001). Our results suggest that GPI variants may play a crucial role in the production of autoantibodies against ubiquitous GPI autoantigens.
authors.affiliation: Department of Internal Medicine, Institute of Clinical Medicine, University of Tsukuba, 1-1-1 Tenodai, Ibaraki 305-8575, Japan.
authors.forename: Yoshifumi
authors.initials: Y
authors.lastname: Muraki
authors.forename: Isao
authors.initials: I
authors.lastname: Matsumoto
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Chino
authors.forename: Taichi
authors.initials: T
authors.lastname: Hayashi
authors.forename: Eiji
authors.initials: E
authors.lastname: Suzuki
authors.forename: Daisuke
authors.initials: D
authors.lastname: Goto
authors.forename: Satoshi
authors.initials: S
authors.lastname: Ito
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Murata
authors.forename: Akito
authors.initials: A
authors.lastname: Tsutsumi
authors.forename: Takayuki
authors.initials: T
authors.lastname: Sumida
mesh_terms: D001172:Arthritis, Rheumatoid / Q000097:blood / Q000201:enzymology* / Q000235:genetics / Q000276:immunology*; D001323:Autoantibodies / Q000737:chemistry / Q000235:genetics / Q000276:immunology*; D001483:Base Sequence; D017353:Gene Deletion; D020022:Genetic Predisposition to Disease / Q000235:genetics; D014644:Genetic Variation; D005956:Glucose-6-Phosphate Isomerase / Q000737:chemistry* / Q000235:genetics / Q000276:immunology*; D006801:Humans; D007527:Isoenzymes / Q000737:chemistry / Q000235:genetics / Q000276:immunology; D007963:Leukocytes, Mononuclear / Q000201:enzymology* / Q000276:immunology*; D008969:Molecular Sequence Data; D020539:Sequence Analysis, Protein; D017386:Sequence Homology, Amino Acid
chemical_list: D001323:Autoantibodies; D007527:Isoenzymes; D005956:Glucose-6-Phosphate Isomerase