Cardiolipin antibodies dependant on beta2-glycoprotein-I in antiphospholipid syndrome

Aim. To study beta2-GP-I-dependant binding of phospholipid antibodies (PAb) to phospholipids and this process participation in pathogenesis of antiphospholipid syndrome (APS). Materials and methods. IgG-fractions and sera from 20 patients with APS. Cofactor activity of beta2-GP-I isolated from serum of healthy donors was examined with modified immunoassay. Results. Contrary to donor IgG, binding of IgG fractions isolated from sera of APS patients with cardiolipin grows dose-dependently in the presence of beta2-GP-I. Cofactor activity of beta2-GP-I is confirmed in the study of sera of APS patients. Sera containing beta2-GP-I-dependant antibodies to cardiolipin (aCL), unlike a CL-negative sera, react with solid-phase immobilized beta2-GP-I. Conclusion. It is confirmed that beta2-GP-I participates in interaction of PAb with cardiolipin. Pathogenetic implication of beta2-GP-I-dependant PAb for onset of APS is discussed.