title: Anti-dsDNA antibodies in Brazilian patients of mainly African descent with systemic lupus erythematosus: lack of association with lupus nephritis.
abstract: Renal disease is associated with morbidity and mortality in systemic lupus erythematosus (SLE) and anti-dsDNA antibodies with SLE immunopathogenesis. We investigated the dsDNA antibody profile of 84 Brazilian SLE patients, 27 with lupus nephritis. Thirty-six (39.1%) patients had dsDNA IgG antibodies shown in enzyme-linked immunosorbent assay (454.7 +/- 281.1 WHO units/mL), nine presenting renal disease. The following profile of dsDNA antibodies was demonstrated in Crithidia luciliae test: IgA (seven out of 36; 19.4%), IgG (22 out of 36, 66.1%); IgM (nine out of 36, 25.0%), and IgE (four out of 36, 11.1%). Two or three isotypes of dsDNA antibodies were observed in nine (25.0%) patients, while 11 (30.5%) were seronegative in the C. luciliae test. Patients with dsDNA antibodies had lower serum C3 and C4 when compared with SLE individuals without these immunoglobulins (P < 0.01 and P < 0.001, respectively). There was no association between any dsDNA antibody isotype and lupus kidney disease nor was anti-dsDNA IgM antibody associated with absence of nephritis.
authors.affiliation: Departamento de Análises Clínicas e Toxicológicas, Faculdade de Farmácia, Universidade Federal da Bahia, 40170115, Salvador, Bahia, Brazil. ajatta@ig.com.br
authors.forename: A M
authors.initials: AM
authors.lastname: Atta
authors.forename: M M
authors.initials: MM
authors.lastname: Pereira
authors.forename: M
authors.initials: M
authors.lastname: Santiago
authors.forename: M L B
authors.initials: ML
authors.lastname: Sousa-Atta
mesh_terms: D000293:Adolescent; D000328:Adult; D000349:Africa / Q000208:ethnology; D000368:Aged; D000818:Animals; D000974:Antibodies, Antinuclear / Q000097:blood*; D000913:Antibodies, Protozoan / Q000378:metabolism; D001938:Brazil; D003421:Crithidia / Q000276:immunology; D004247:DNA / Q000276:immunology*; D005260:Female; D006801:Humans; D007070:Immunoglobulin A / Q000097:blood; D007073:Immunoglobulin E / Q000097:blood; D007074:Immunoglobulin G / Q000097:blood; D007075:Immunoglobulin M / Q000097:blood; D008180:Lupus Erythematosus, Systemic / Q000097:blood / Q000208:ethnology* / Q000276:immunology*; D008181:Lupus Nephritis / Q000097:blood / Q000208:ethnology* / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D055815:Young Adult
chemical_list: D000974:Antibodies, Antinuclear; D000913:Antibodies, Protozoan; D007070:Immunoglobulin A; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D007073:Immunoglobulin E; D004247:DNA