IGM ANTI-DSDNA ANTIBODIES IN SYSTEMIC LUPUS-ERYTHEMATOSUS - NEGATIVE ASSOCIATION WITH NEPHRITIS

Antibodies against dsDNA of the IgM class were measured in sera of 352 patients with systemic lupus erythematosus, 81 blood donors and 189 p atients with rheumatoid arthritis using a new ELISA based on human rec ombinant dsDNA as antigen. IgM anti-dsDNA antibodies were found in 52. 3% of the sera from patients with systemic lupus erythematosus, but in none of the sera from 81 normal controls and 189 patients with rheuma toid arthritis. The association of these autoantibodies with 31 clinic al and 37 laboratory parameters was calculated. There was a highly sig nificant negative correlation between IgM anti-dsDNA antibodies and ne phritis as well as all the laboratory parameters indicating renal dise ase (elevated serum creatinine concentration, proteinuria, erythrocyte casts in the urine). IgM anti-dsDNA antibodies indicate protection of lupus patients against the development of lupus nephritis. Further ex periments will show whether application of IgM anti-dsDNA antibodies i s effective in treating lupus nephritis.