ANTIBODIES TO BETA(2)-GLYCOPROTEIN-I - A POTENTIAL MARKER FOR CLINICAL-FEATURES OF ANTIPHOSPHOLIPID ANTIBODY SYNDROME IN PATIENTS WITH SYSTEMIC LUPUS-ERYTHEMATOSUS

Objective, To clarify risk factors for the development of clinical fea tures of antiphospholipid syndrome (APS) in patients with anticardioli pin antibodies (aCL) in systemic lupus erythematosus (SLE). Methods, W e studied 65 SLE patients, all with positive IgG and/or IgM aCL. Patie nts were divided into 2 groups; I: 29 SLE patients with features of AP S (SLE/APS) and II: 36 aCL positive SLE patients without any feature o f APS (SLE/aCL). Serum samples were collected from our serum bank. Ant i-beta(2)-glycoprotein I (anti-beta(2)-GPI) were tested by ELISA using irradiated plates in the absence of cardiolipin. Anti-dsDNA antibodie s were tested by standard Farr assay. Results. There were no major dif ferences between SLE clinical manifestations in both groups. However, the frequency of IgG anti-beta(2)-GPI was markedly increased in SLE/AP S (18/29, 62%) than in SLE/aCL (4/36, 11%) (chi-squared 18.6, p = 0.00 01). The levels of anti-dsDNA antibodies in the same samples were slig htly lower in SLE/APS. Conclusion. Our data suggest that increased lev els of IgG anti-beta(2)-GPI may be a specific feature of SLE/APS patie nts rather than reflecting a polyclonal B cell activation.