Determination of anti-ds-DNA antibodies by three different methods: Comparison of sensitivity, specificity and correlation with lupus activity index (LAI)

Abstract

Ninety-seven sera, 58 from patients with SLE and 39 from patients with other autoimmune rheumatic diseases were tested for anti-ds-DNA antibody activity by ELISA, Farr, and Crithidia Lucilliae assays. Fifty-six per cent of the sera were positive by at least one method. Eighty per cent of the SLE population was positive by ELISA, 39% by Farr Assay and 33% by the Crithidia assay. Crithidia assay exhibited the greater specificity (100%) followed by the Farr Assay (97%) and the ELISA (80%). Sera positive by all methods showed a significantly higher mean value of the ELISA rates, than sera positive only by ELISA (p.