RT Journal Article
SR Electronic
T1 Measurement of anti-DNA antibodies: a reappraisal using five different methods.
JF Annals of the Rheumatic Diseases
JO Ann Rheum Dis
FD BMJ Publishing Group Ltd and European League Against Rheumatism
SP 448
OP 456
DO 10.1136/ard.46.6.448
VO 46
IS 6
A1 D A Isenberg
A1 C Dudeney
A1 W Williams
A1 I Addison
A1 S Charles
A1 J Clarke
A1 A Todd-Pokropek
YR 1987
UL http://ard.bmj.com/content/46/6/448.abstract
AB One hundred and thirty coded sera, 60 from patients with systemic lupus erythematosus (SLE) and 70 from patients with other autoimmune rheumatic diseases were tested for deoxyribonucleic acid (DNA) binding activity by five different types of assay. These were enzyme linked immunosorbent assay (ELISA) (distinguishing IgG and IgM anti-ssDNA and anti-dsDNA), Crithidia luciliae, a nitrocellulose filter assay, the Amersham kit, and another modified Farr assay, the radioimmunoassay (RIA) (UK). The Crithidia test was the most specific, none of the controls was positive, but the least sensitive (13% positive only). The RIA (UK) was the most sensitive (57% positive). In most of the assays 3-9% of the controls were positive. When the SLE sera were analysed according to disease activity the IgG anti-dsDNA ELISA, all three RIA values, and the Crithidia test values were raised in all the patients with severely active disease. Some patients with inactive disease, however, were positive in each of the tests. The best interassay correlations (r less than 0.49) were found between RIA (UK), and ss IgG and the Amersham kit; and between ds IgG and ss IgG. In the main, however, it was clear that different assays are dependent upon distinctive properties of DNA antibodies. It seems inevitable that most major rheumatology units will require more than one anti-DNA antibody assay.