[Anti-DNA determination using Crithidia luciliae. Specificity and clinical usefulness in systemic lupus...

The authors determined the existence of native anti-DNA antibodies by the crithidia lucilae (anti-DNA-CL) test in 44 patients suffering from systemic lupus erythematosus (SLE), 48 with rheumatoid arthritis (RA), 12 with scleroderma, 8 with polymyositis and/or dermatomyositis, 12 with mixed connective tissue disease, 53 with chronic liver disease and 100 blood donors in order to establish the specificity of the test in SLE, its possible correlation with the degree of clinical activity and the presence or absence of neuropathy, and its possible use in the therapeutic control of the disease. The presence of anti DNA-CL was specific to SLE. It was seen at significant titres only in patients with active disease. Anti DNA-CL antibodies capable of activating complement were seen more frequently and at higher titres in cases with active nephritis. In longitudinal studies it was seen that clinical activity or inactivity were associated with parallel oscillations in anti DNA-CL titres. These data confirmed the specificity of the method and its usefulness in the diagnosis and therapeutic control of the process.