Specificity of anti-Sm antibodies by ELISA for systemic lupus erythematosus: increased sensitivity of detection using purified peptide antigens.
Sm antigen was purified by immunoaffinity chromatography using a murine monoclonal anti-Sm antibody and was confirmed to be free from contaminating polypeptides. This was then used to detect anti-Sm antibodies in patients' sera by enzyme linked immunosorbent assay (ELISA). Antibodies against Sm were detected in only 9/52 (17%) patients with systemic lupus erythematosus (SLE) by immunodiffusion, but 15/52 (29%) were positive for IgG anti-Sm antibodies by ELISA. The presence of anti-Sm antibodies remained disease specific despite the increase in sensitivity of this assay and validates its potential use for clinical application. There was no correlation between the presence of anti-Sm antibodies and any clinical features of SLE. In 23 renal biopsies a membranous component to the glomerulonephritis correlated with anti-Sm antibodies (p less than 0.05). Patients from West Africa, the Carribean Islands, and Asia had a higher prevalence of anti-Sm antibodies than the local Caucasian population.
D000918:Antibody Specificity; D001323:Autoantibodies / Q000032:analysis*; D001324:Autoantigens / Q000032:analysis / Q000276:immunology*; D004591:Electrophoresis, Polyacrylamide Gel; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D005779:Immunodiffusion; D007668:Kidney / Q000473:pathology; D008180:Lupus Erythematosus, Systemic / Q000276:immunology* / Q000473:pathology; D010455:Peptides / Q000276:immunology; D017411:Ribonucleoproteins, Small Nuclear; D055517:snRNP Core Proteins
D001323:Autoantibodies; D001324:Autoantigens; D010455:Peptides; D017411:Ribonucleoproteins, Small Nuclear; D055517:snRNP Core Proteins