The lupus anticoagulant. A disease marker in antinuclear antibody negative lupus that is cross‐reactive with autoantibodies to double‐stranded DNA

摘要

AbstractThe lupus anticoagulant (LA) was demonstrated in 37 of 52 consecutive systemic lupus erythematosus (SLE) patients and patients with lupus‐like syndromes, who were referred to our unit. The LA was found to be associated with a biologic false‐positive VDRL (P<0.005), and the apparently paradoxical association of LA with vascular thromboses was confirmed (P<0.05). The presence of LA and a biologic false‐positive VDRL defined a group of 7 antinuclear antibody negative patients with characteristic features of recurrent thromboses, spontaneous abortions, neurologic involvement, and renal disease. Further studies on 6 selected sera demonstrated LA in all 6 IgM fractions and in 3 of 6 IgG fractions. Inhibition of LA was shown in 6 of 9 Ig fractions after absorption with double‐stranded DNA (dsDNA). Anticardiolipin antibody was shown by immunodiffusion in 3 LA positive IgG fractions from VDRL negative sera. Cardiolipin micelles partially inhibited anti‐dsDNA binding of 4 IgG fractions, 3 of which were LA negative. In this report we discuss the overlapping specificities due to cross‐reactivity between LA, anticardiolipin, and anti‐dsDNA antibodies in human SLE, and we suggest that LA be considered equivalent to the biologic false‐positive VDRL as a criterion for the d