title: Antibodies to new cytoplasmic autoantigens: anti-JA, a potential marker for disease activity in systemic lupus erythematosus.
abstract: 1. We describe new autoantibodies which recognize two cytoplasmic proteins of 30 and 26 kDa. They were detected by Western blot analysis in the sera of 6 of 79 randomly selected systemic lupus erythematosus (SLE) patients and are denoted anti-JA antibodies. This antibody specificity is different from the previously described lupus autoantibodies, anti-P and anti-S10. 2. The targeted autoantigens are trypsin sensitive, and resistant to RNase and DNase treatment. The binding to the antigens was not modified when reticulocyte ribosomes were prepared with protease inhibitors indicating that these are primary antigens and not degradation products. Several lines of evidence suggest that these proteins are almost certainly part of the ribosome. 3. Anti-JA reactivity was not observed in the sera from 60 patients with other autoimmune diseases or from normal individuals. In contrast, 55% of lupus sera selected for a high titer of anti-dsDNA (double stranded DNA) and LE cells were also anti-JA positive. 4. Anti-JA antibodies may be useful as a specific serological marker for disease activity in SLE. The strong association with anti-dsDNA antibodies and LE cell in the sera of SLE patients requires further study.
authors.affiliation: Departamento de Clínica Médica, Universidade de São Paulo, Brasil.
authors.forename: E
authors.initials: E
authors.lastname: Bonfa
authors.forename: A V
authors.initials: AV
authors.lastname: Tavares
authors.forename: V S
authors.initials: VS
authors.lastname: Viana
authors.forename: M
authors.initials: M
authors.lastname: Levy-Neto
authors.forename: C A
authors.initials: CA
authors.lastname: Kumeda
authors.forename: W
authors.initials: W
authors.lastname: Cossermelli
mesh_terms: D000918:Antibody Specificity; D001323:Autoantibodies / Q000097:blood*; D001324:Autoantigens / Q000097:blood / Q000276:immunology*; D001327:Autoimmune Diseases / Q000175:diagnosis* / Q000453:epidemiology; D015415:Biomarkers / Q000097:blood; D015153:Blotting, Western; D016009:Chi-Square Distribution; D003593:Cytoplasm / Q000276:immunology*; D005455:Fluorescent Antibody Technique; D006801:Humans; D008180:Lupus Erythematosus, Systemic / Q000175:diagnosis* / Q000453:epidemiology; D008970:Molecular Weight; D012189:Retrospective Studies; D012270:Ribosomes / Q000276:immunology*
chemical_list: D001323:Autoantibodies; D001324:Autoantigens; D015415:Biomarkers; C085221:JA antigen