title: Changes in levels of antibodies against the 70 kDa and a polypeptides of the U1RNP complex in relation to exacerbations of systemic lupus erythematosus.
abstract: In order to investigate whether disease exacerbations of systemic lupus erythematosus (SLE) are accompanied or preceded by changes in antibody levels against the U1RNA associated 70 kDa and A polypeptides, we prospectively collected plasma specimens from 71 patients with SLE. We compared changes in anti-70 kDa/anti-A levels, measured by ELISA using cloned antigens, with changes in levels of anti-dsDNA and total IgG. Measurable levels of anti-70 kDa (n = 10) and/or anti-A antibodies (n = 6) were detected during 10 exacerbations. Four of the 10 exacerbations with a measurable level of anti-70 kDa antibodies were preceded by a significant rise in anti-70 kDa levels, 2 by a significant fall, while levels of anti-70 kDa did not change in the remaining 4 cases. Only one of the 6 exacerbations with detectable anti-A antibody levels was preceded by a significant rise in anti-A antibodies, while levels did not change before exacerbation in the other 5 cases. Six of the 10 exacerbations were preceded by a significant rise in anti-dsDNA; in 4 cases levels of anti-dsDNA did not change before exacerbation. In contrast to anti-dsDNA, no relation was found between changes in levels of anti-70 kDa/anti-A and changes in disease activity. Significant changes in levels of anti-70 kDa/anti-A, occurring in 6 cases, were accompanied by parallel changes in total IgG in 5 of these 6. We conclude that, in contrast to anti-dsDNA, serial measurement of levels of anti-70 kDa/anti-A is not useful for monitoring disease activity or predicting disease exacerbations in SLE.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Department of Internal Medicine, University Hospital, Groningen, The Netherlands.
authors.forename: E J
authors.initials: EJ
authors.lastname: ter Borg
authors.forename: G
authors.initials: G
authors.lastname: Horst
authors.forename: P C
authors.initials: PC
authors.lastname: Limburg
authors.forename: W J
authors.initials: WJ
authors.lastname: van Venrooij
authors.forename: C G
authors.initials: CG
authors.lastname: Kallenberg
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000974:Antibodies, Antinuclear / Q000032:analysis*; D000945:Antigens, Differentiation, T-Lymphocyte / Q000276:immunology; D017252:CD3 Complex; D015704:CD4 Antigens / Q000276:immunology; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D007074:Immunoglobulin G / Q000032:analysis; D008180:Lupus Erythematosus, Systemic / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D010446:Peptide Fragments / Q000276:immunology*; D010455:Peptides / Q000276:immunology*; D011446:Prospective Studies; D011948:Receptors, Antigen, T-Cell / Q000276:immunology; D012261:Ribonucleoproteins / Q000276:immunology*; D017411:Ribonucleoproteins, Small Nuclear
chemical_list: D000974:Antibodies, Antinuclear; D000945:Antigens, Differentiation, T-Lymphocyte; D017252:CD3 Complex; D015704:CD4 Antigens; D007074:Immunoglobulin G; D010446:Peptide Fragments; D010455:Peptides; D011948:Receptors, Antigen, T-Cell; D012261:Ribonucleoproteins; D017411:Ribonucleoproteins, Small Nuclear