IgG anti-beta(2)-glycoprotein I antibodies in adult patients with systemiclupus erythematosus: Prevalence and diagnostic value for the antiphospholipid syndrome

Objective. To investigate the prevalence of serum anti-beta(2)-glycoprotein I (anti-beta(2)-GPI) antibodies and other antiphospholipid antibodies (aPL ) in patients with systemic lupus erythematosus (SLE), To study their diagn ostic value for the antiphospholipid syndrome (APS). Methods. Anti-beta(2)- GPI and IgG anticardiolipin (aCL) were determined in sera from 102 consecut ive patients with SLE using ELISA. Serum and plasma tests were also done fo r lupus anticoagulant (LAC), syphilis, and antibodies to dsDNA. Clinical an d laboratory features of APS were observed, Results. Prevalences were 23.5% for aCL and 18.6% for anti-beta(2)-GPI. Correlations between the presence of aCL and anti-beta(2)-GPI and between their titers were statistically sig nificant (p < 0.0001). No associations were found between anti-beta(2)-GPI and disease activity criteria (SLEDAI, ECLAM, dsDNA), Anti-beta(2)-GPI were significantly associated with LAC (p = 0,005), APS (p = 0.005), and a high aCL titer (aCL > 5 SD; p less than or equal to 0.001). LAC was the best di agnostic criterion for APS. Conclusion, These data suggest that determinati on of anti-beta(2)-GPI in addition to aCL and LAC is unlikely to improve th e diagnosis of APS in patients with SLE.