title: Specificity of antibodies to single-stranded (ss) DNA in SLE patients with anti-phospholipid syndrome.
abstract: Although the concept of anti-phospholipid syndrome has been proposed in patients with SLE and other rheumatic diseases, the immunological mechanism is still controversial. Recently, the crossreactivity between anti-cardiolipin antibody and anti-ssDNA antibodies has been discussed in relation to this syndrome. In the present study, the specificity such as the avidity and the crossreactivity of anti-ssDNA antibodies was examined to find a clue to clarify the question why all of anti-cardiolipin antibody positive patients do not have any specific clinical features, thrombosis and spontaneous abortion. The avidity of IgG anti-ssDNA antibodies was examined by salt elution studies in solid phase ELISA. The avidity of anti-ssDNA antibodies tended to be lower in 10 patients with specific features than in other 10 patients without those features. The crossreactivity of affinity purified IgG anti-ssDNA antibodies was investigated by competitive ELISA. Purified anti-ssDNA antibodies from 4 patients without specific features were slightly inhibited by negatively charged phospholipids, cardiolipin and phosphatidylserine, whereas purified anti-ssDNA antibodies from 2 patients with specific features, who were considered to have anti-phospholipid syndrome, were little inhibited by these phospholipids. The above results suggest that the specificity of anti-ssDNA antibodies appears, at least partly, in different manners whether specific features are present or absent in anti-cardiolipin antibody positive patients. Moreover, anti-ssDNA antibodies and anti-phospholipid antibodies may form separate groups of antibodies in patients with anti-phospholipid syndrome.
authors.affiliation: Department of Internal Medicine, Tokyo Electric Power Company Hospital, Japan.
authors.forename: J
authors.initials: J
authors.lastname: Kaburaki
authors.forename: M
authors.initials: M
authors.lastname: Kuwana
authors.forename: T
authors.initials: T
authors.lastname: Ogasawara
authors.forename: M
authors.initials: M
authors.lastname: Takano
authors.forename: Y
authors.initials: Y
authors.lastname: Funatsu
authors.forename: T
authors.initials: T
authors.lastname: Tojo
mesh_terms: D000918:Antibody Specificity; D001323:Autoantibodies / Q000097:blood; D004277:DNA, Single-Stranded / Q000276:immunology*; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D008180:Lupus Erythematosus, Systemic / Q000276:immunology*; D010743:Phospholipids / Q000276:immunology; D013577:Syndrome
chemical_list: D001323:Autoantibodies; D004277:DNA, Single-Stranded; D007074:Immunoglobulin G; D010743:Phospholipids