title: The SL autoantibody-antigen system: clinical and biochemical studies.
abstract: A recently described autoantibody, SL, was found in serum from 27 patients with autoimmune disease, including 20 with systemic lupus erythematosus (SLE) where the frequently was 7%. Analysis of clinical, serological, and HLA data from 119 SLE patients showed no positive associations with anti-SL antibody apart from a higher frequency of non-infective fever. Most SL positive sera contained other precipitins, notably antibodies to Ro(SS-A) and the proliferating cell nuclear antigen, PCNA. Anti-SL IgG recognised a protein of 32 000 daltons without associated RNA. This polypeptide was distinguished from a similarly sized component of the Sm and RNP ribonucleoprotein particles by demonstrating different products of partial proteolysis. Although anti-SL antibody is of limited clinical importance, it occurs with twice the frequency of anti-SM antibody in white patients with SLE. Preliminary studies indicate that SL and the Japanese Ki system are identical.
mesh_terms: D000974:Antibodies, Antinuclear / Q000276:immunology; D001323:Autoantibodies / Q000276:immunology*; D001327:Autoimmune Diseases / Q000276:immunology*; D011232:Chemical Precipitation; D004591:Electrophoresis, Polyacrylamide Gel; D006801:Humans; D007122:Immunoelectrophoresis; D008180:Lupus Erythematosus, Systemic / Q000276:immunology*; D010446:Peptide Fragments / Q000032:analysis
chemical_list: D000974:Antibodies, Antinuclear; D001323:Autoantibodies; D010446:Peptide Fragments