Abstract
The clinical importance of IgG anticardiolipin antibodies was investigated in systemic lupus erythematosus (SLE). IgG anticardiolipin antibodies were found in 69 of 155 (44.5%) patients with SLE. Serial measurements of IgG anticardiolipin antibodies allowed the patients to be classified into two groups: group A, persistently positive for IgG anticardiolipin antibodies; group B, positive only in active phases. The IgG anticardiolipin antibody titre in group A was significantly higher than in group B. The incidence of thromboses, spontaneous abortions, and lupus anticoagulant in group A was significantly higher than in group B (p less than 0.05). By contrast, the incidence of renal diseases and anti-dsDNA antibodies in group B was significantly higher than in group A (p less than 0.05). This study showed that group A formed a separate subgroup of patients with SLE who had a high risk of thromboses and spontaneous abortions despite having milder disease activity.