COMPARISON OF DIFFERENT METHODS FOR THE DETECTION OF AUTOANTIBODIES IN AUTOIMMUNE-DISEASES

Different immunological techniques were compared for their sensitivity in detecting some important autoantibodies in the sera of patients wi th rheumatic diseases. Sera of patients with systemic lupus erythemato sus were screened for anti-dsDNA, Sm, and RNP autoantibodies by Crithi dia luciliae assay, Farr assay, enzyme immunoassay, and immunoblotting . Sera of patients with Sjogren's syndrome were screened for anti-SSA and anti-SSB antibodies by enzyme immunoassay, counter immunoelectroph oresis, and immunoblotting and sera of patients with scleroderma for S CL-70 autoantibodies by enzyme immunoassay counter immunoelectrophores is, and immunofluorescence on Hep-2 cells. Enzyme immunoassay and coun ter immunoelectrophoresis gave the most positive results and the best agreement compared with the other techniques. Immunofluorescence gave few positive results for each antibody evaluated. Immunoblotting gave intermediate results for all autoantibodies except anti-SSA, where the prevalence was low. There was no relationship between levels of dsDNA , Sm, and RNP antibodies and disease activity score in systemic lupus erythematosus patients.