[The evaluation of anti-native dna antibodies. Comparison of two methods of dosage, study of reproducibility, and diagnostic value of each method].
The duplicatibility of dosing anti-native (double-stranded) DNA antibodies using Farr's radioimmunological method (RIE) and indirect immunofluorescence on Crithidia luciliae (IF-CL) has been demonstrated in the literature and from a multicenter study undertaken in 10 immunological laboratories. The duplicatibility of tests run at the same time and also between tests done at different intervals by RIE in our laboratory was better than that by IF-CL. The coefficients of maximum change were respectively 3% (variation in results during one run of the test), and 6% (variation in results between different runs of the test) for the RIE method and 34% (variation during one run) and 38% (variation between different runs) using the IF-CL method. This multicenter study showed that the duplicatibility of Farr's radioimmunological test was good among the different laboratories, only antibody levels near the upper limit of normal giving some discordant results were found in 91%, the discordant results being due to falsely-positive or falsely-negative tests, and sometimes also to the differing affinity of the anti-native DNA antibodies in the two methods. The sensitivity of both methods in making a diagnosis of systemic lupus erythematosus from the literature varies from 60 to 98% for the RIE method and from 44 to 98% for the IF-CL method. The predictive value of a positive test between these two methods varies from 65 to 100% depending on the series, which means that there are other conditions than systemic lupus erythematosus (SLE) (rheumatoid arthritis, Sjögren's syndrome, hepatitis...) where anti-native DNA antibodies can be found.
D000328:Adult; D000368:Aged; D000906:Antibodies / Q000032:analysis*; D001172:Arthritis, Rheumatoid / Q000276:immunology; D003421:Crithidia; D004247:DNA / Q000276:immunology*; D005260:Female; D005455:Fluorescent Antibody Technique; D005921:Glomerulonephritis / Q000276:immunology; D006801:Humans; D008180:Lupus Erythematosus, Systemic / Q000276:immunology; D008297:Male; D008875:Middle Aged; D011863:Radioimmunoassay
D000906:Antibodies; D004247:DNA
Evaluation des anticorps anti-ADN natif en rhumatologie. Comparaison de deux méthodes de dosage, étude de reproductibilité, valeur diagnostique de chaque méthode.