[Determination of anti dsDNA antibodies by immunofluorescence using Crithidia luciliae. I--Diagnostic and prognostic value in systemic lupus erythematosus. Comparison with the Farr radioimmunoassay].
Antibodies to double stranded (ds) DNA were sought by the indirect immunofluorescence method using Crithidia luciliae in 196 sera from patients suffering from hepatic, thyroid or inflammatory rheumatic disorders. Anti ds DNA antibodies were demonstrated in 29 out of 45 systemic lupus erythematosus (SLE) sera. Lower titers were found in 3 out of 7 sera from drug-induced SLE, 2 out of 6 from mixed connective tissue diseases, 1 out of 60 from scleroderma, 2 from unclassified arthritis, 8 out of 40 from rheumatoid arthritis with antinuclear factors, and in 4 out of 15 sera from chronic hepatitis. For SLE diagnosis the sensitivity of the method was 73 percent, its specificity was 87 percent. 84 percent of these results were in agreement with those obtained with the Farr method, but titers did not correlate well. The sensitivity of the Farr method was 64.5 percent, its specificity was 85 percent. In this study, high titers of anti ds DNA antibodies demonstrated on Crithidia Luciliae did not correlate with disease severity. Low titers of anti14C labelled DNA antibodies demonstrated by the Farr assay correlated with inactive SLE without nephritis. The immunofluorescence assay using Crithidia luciliae is a valid method to detect anti ds DNA antibodies but does not allow prognostic conclusions in SLE.
D000818:Animals; D001323:Autoantibodies / Q000032:analysis*; D003421:Crithidia; D004247:DNA / Q000276:immunology*; D005455:Fluorescent Antibody Technique; D006801:Humans; D008180:Lupus Erythematosus, Systemic / Q000175:diagnosis / Q000276:immunology*; D011379:Prognosis; D011863:Radioimmunoassay
D001323:Autoantibodies; D004247:DNA
Dosage des anticorps anti-ADNn par immunofluorescence sur Crithidia luciliae. I--Valeur diagnostique et pronostique au cours de la maladie lupique. Comparaison avec le dosage radio-immunologique de Farr.