title: Serum antibodies against the 70k polypeptides of the U1 ribonucleoprotein complex are associated with psychiatric syndromes in systemic lupus erythematosus: a retrospective study.
abstract: OBJECTIVE
  We assessed the association between serum autoantibodies against the 70-kDa polypeptide of the U1-ribonucleoprotein (RNP) complex (U1-70k) and the central nervous system (CNS) syndromes in systemic lupus erythematosus (SLE) patients.
  
  
  METHODS
  We studied 106 hospitalized patients with active SLE, comparing those with (n = 32) and without (n = 74) CNS syndromes. CNS syndromes were further classified into neurologic (n = 21) and psychiatric (n = 15) disorders. Immunoglobulin G (IgG) anti-U1-70k antibodies were measured by enzyme-linked immunosorbent assay (ELISA) using recombinant antigens. IgG antibodies against whole U1-RNP were measured using commercial ELISA kits.
  
  
  RESULTS
  Although there was no significant difference in the levels of serum anti-U1-70k antibodies in SLE patients with or without CNS syndromes (p = 0.83), the levels were significantly elevated in SLE patients compared with patients without psychiatric syndromes (p = 0.030). In contrast, no significant difference was observed in the levels of serum anti-U1-RNP antibodies in SLE patients with or without psychiatric syndromes (p = 0.555).
  
  
  CONCLUSIONS
  These results indicate that serum anti-U1-70k antibodies are associated with psychiatric syndromes in SLE but that they are not associated with CNS syndromes as a whole or with neurologic syndromes. The anti-U1-70k antibodies might be involved in the pathological mechanisms of psychiatric syndromes in SLE.
authors.affiliation: Institute of Rheumatology, Tokyo Women's Medical University, 10-22 Kawada-cho, Shinjuku-ku, Tokyo, 162-0054, Japan. katsumata@ior.twmu.ac.jp
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Katsumata
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Kawaguchi
authors.forename: Sayumi
authors.initials: S
authors.lastname: Baba
authors.forename: Seisuke
authors.initials: S
authors.lastname: Hattori
authors.forename: Koji
authors.initials: K
authors.lastname: Tahara
authors.forename: Kaori
authors.initials: K
authors.lastname: Ito
authors.forename: Tadao
authors.initials: T
authors.lastname: Iwasaki
authors.forename: Nozomi
authors.initials: N
authors.lastname: Yamaguchi
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Hattori
authors.forename: Kinya
authors.initials: K
authors.lastname: Nagata
authors.forename: Yuko
authors.initials: Y
authors.lastname: Okamoto
authors.forename: Hisashi
authors.initials: H
authors.lastname: Yamanaka
authors.forename: Masako
authors.initials: M
authors.lastname: Hara
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000974:Antibodies, Antinuclear / Q000097:blood*; D005260:Female; D006801:Humans; D020945:Lupus Vasculitis, Central Nervous System / Q000097:blood* / Q000150:complications; D008297:Male; D008875:Middle Aged; D008970:Molecular Weight; D010455:Peptides / Q000276:immunology; D011618:Psychotic Disorders / Q000097:blood* / Q000209:etiology; D011994:Recombinant Proteins; D012189:Retrospective Studies; D017412:Ribonucleoprotein, U1 Small Nuclear / Q000276:immunology*; D013577:Syndrome; D055815:Young Adult
chemical_list: D000974:Antibodies, Antinuclear; D010455:Peptides; D011994:Recombinant Proteins; D017412:Ribonucleoprotein, U1 Small Nuclear; C490688:SNRNP70 protein, human