[The Ha(La) antibody as a serologic marker of systemic lupus erythematosus].

Ha(La)-antibodies are detected by counterimmunoelectrophoresis (CIE) in sera of systemic lupus erythematosus (SLE) patients, but not in sera of patients with progressive systemic scleroderma (PSS) (n = 38), rheumatoid arthritis (n = 91), ankylosing spondylitis (n = 97), and other rheumatic diseases (n = 452). This antibody specificity was found in 27 out of 103 SLE patients (26%). However, 50% of SLE patients with Sjögren's syndrome (n = 12) showed the Ha(La)-antibody, suggesting a strong association in this clinical subgroup. Thus the Ha(La)-antibody can serve as a serological marker and helpful diagnostic tool for SLE. Additionally, the Ha(La)-antibody reacts with specific puffs in polytene chromosome preparations of Drosophila melanogaster. Therefore, this heterologous antigen system is suitable for the identification of Ha(La) sera.