Abstract
Background Antiphospholipid syndrome (APS) is acquired thrombophilia characterized by the presence of antiphospholipid antibodies (aPL). Its main manifestations are vascular thromboses and pregnancy complications. Despite apparently adequate anticoagulation, the risk of recurrent thrombosis remains high.
The aim. To evaluate the relationship between aPL and recurrent thrombosis in patients with primary APS (PAPS).
Methods The study included 52 patients with PAPS: 30 (58%) – women and 22 (42%) – men. The mean age of the patients was 38.5 [31.5–43.5] years, duration of the disease – 9.0 [3.1–13.0] years. Recurrent thromboses had 34 (65%)/52 patients and no recurrent thromboses had 18 (35%)/52. The study of aPL involved the determination of IgG/IgM antibodies to cardiolipin (aCL), IgG/IgM antibodies to β2 glycoprotein 1 (anti-β2GP1) and IgG/IgM antibodies to phosphatidylserine-prothrombin complex (aPs/Pt) by enzyme immunoassay (ELISA), IgG/IgM/IgA aCL, IgG/IgM/IgA anti-β2GP1, IgG antibodies to domain I β2 glycoprotein 1 (IgG anti-β2GP1DI) by chemiluminescence assay (CLA).
Results IgM aCL and IgM anti-β2GP1 were not associated with recurrent thrombosis, in contrast to IgG aPL (ELISA/CLA); figure 1. There was an association between recurrent thrombosis and «extra»-criteria aPLs: IgG aPs/Pt, IgA aCL, IgG anti-β2GP1DI.
Combination of IgG aCL+IgG anti-β2GP1+IgG aPs/Pt (ELISA) was 34/52 (65%) patients and thrombosis recurred in 27 (79%)/34; p=0.008. Thirty-six (69%)/48 patients had a combination of IgG aCL+IgG anti-β2GP1+IgG anti-β2GP1DI (CLA). Recurrent thromboses had 29 (81%)/36; p=0.0003. . Relationship between antiphospholipid antibodies and recurrent thrombosis in patients with primary antiphospholipid syndrome is shown in table 1.
Conclusions Recurrent thrombosis was associated with triple IgG aPL positivity in any combination Patients with positive IgG aPL (ELISA/CLA) and IgA aCL were significantly more likely to have recurrent thrombosis. The highest relationship was observed with IgG anti-β2GP1DI (CLA) and IgG anti-β2GP1.
