title: Association of cerebrospinal fluid anti-ribosomal p protein antibodies with diffuse psychiatric/neuropsychological syndromes in systemic lupus erythematosus.
abstract: We explored the relationship of antibodies to the whole ribosomal P proteins (P0, P1, and P2) in cerebrospinal fluid (CSF) with diffuse psychiatric/neuropsychological syndromes in systemic lupus erythematosus (SLE). CSF samples were obtained from 71 SLE patients (52 patients with diffuse psychiatric/neuropsychological syndromes [diffuse NP-SLE] and 19 patients with neurological syndromes or peripheral neuropathy [focal NP-SLE]) as well as from 24 patients with non-inflammatory neurological disease. Immunoglobulin G (IgG) antibodies to the C-terminal 22-amino acid ribosomal P synthetic peptide (anti-PC22) and those to purified bovine ribosomal P proteins (P0, P1, and P2) (anti-whole P) were determined by enzyme-linked immunosorbent assay; affinity-purified IgG anti-PC22 were used as the standard. The concentrations of antibodies to epitopes other than the C-terminal 22 amino acids of ribosomal P proteins were calculated by subtracting anti-PC22 from anti-whole P (anti-PEX.C22). CSF anti-whole P levels were significantly elevated in diffuse NP-SLE compared with focal NP-SLE or control patients. By contrast, there were no significant differences in CSF anti-PC22 levels among the three groups. Of note, CSF anti-PEX.C22 levels were significantly elevated in diffuse NP-SLE compared with the other two groups. CSF anti-PEX.C22 levels were not significantly correlated with CSF anti-PC22 levels, but with CSF antibodies against the recombinant ribosomal P0 protein lacking the C-terminal 22 amino acids (C22-depleted rP0). Moreover, levels of CSF anti-PEX.C22 or CSF anti-C22-depleted rP0, but not CSF anti-PC22, were significantly correlated with CSF anti-neuronal cell antibodies (anti-N). These results indicate that CSF IgG antibodies to the epitopes other than the C-terminal 22 amino acids of ribosomal P proteins, which might contain one of the major targets of CSF anti-N, are associated with the development of diffuse NP-SLE.
authors.affiliation: Department of Rheumatology and Infectious Disease, Kitasato University School of Medicine, 1-15-1 Kitasato, Sagamihara, Kanagawa 228-8555, Japan. shunsei@med.teikyo-u.ac.jp
authors.forename: Shunsei
authors.initials: S
authors.lastname: Hirohata
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Arinuma
authors.forename: Maki
authors.initials: M
authors.lastname: Takayama
authors.forename: Taku
authors.initials: T
authors.lastname: Yoshio
mesh_terms: D001323:Autoantibodies / Q000134:cerebrospinal fluid*; D018985:Epitopes, B-Lymphocyte / Q000276:immunology; D006801:Humans; D007074:Immunoglobulin G / Q000134:cerebrospinal fluid; D008180:Lupus Erythematosus, Systemic / Q000134:cerebrospinal fluid* / Q000276:immunology* / Q000523:psychology; D001523:Mental Disorders / Q000134:cerebrospinal fluid / Q000209:etiology / Q000276:immunology*; D010455:Peptides / Q000276:immunology; D012269:Ribosomal Proteins / Q000276:immunology*
chemical_list: D001323:Autoantibodies; D018985:Epitopes, B-Lymphocyte; D007074:Immunoglobulin G; D010455:Peptides; D012269:Ribosomal Proteins