Study of antiphospholipid antibodies by enzyme immunoassay and chemiluminescent methods in patients with antiphospholipid syndrome and systemic lupus erythematosus (preliminary data).

Antiphospholipid antibodies (aPL) are a family of different autoantibodies that lead to recurrent vascular thrombosis of any localization and caliber, and/or obstetric pathology - fetal loss. Serological markers of antiphospholipid syndrome (APS) include only three types of aPL - lupus anticoagulant (VA), antibodies to cardiolipin (aCL) classes IgG and IgM, antibodies to β2-glycoprotein1 (aβ2GP1) classes IgG and IgM. Medium and high levels of aCL and aß2HP1 (IgG and / or IgM) were selected as serological markers of APS in the 2006 classification criteria. However, the threshold of values used from low to moderately high levels has not been standardized. aPL standardization issues are still unresolved, resulting in heterogeneous results of the ongoing studies. The aim of the study was to assess the comparability IgG/IgM-aCL and IgG/IgM-ab2GP1 by enzyme-linked immunosorbent assay and chemiluminescent analysis in patients with APS with and without (systemic lupus erythematosus) SLE. The study included 70 patients (49 women and 21 men) with APS, of which 21 (30%) were with primary APS (pAPS) and 49 (70%) with APS in combination with SLE. All study participants underwent determination of IgG/IgM-aCL and IgG/IgM-aβ2GP1 by enzyme-linked immunosorbent. A study was performed by the chemiluminescent analysis: IgG/IgM-aCL - in 70 patients; IgG/IgM-aβ2GP1 - in 69 patients. Results. According to preliminary data, the determination of IgG-aCL and IgG-aβ2GP1 by the chemiluminescent analysis is informative in assessing positivity according to the manufacturer, compared with the enzyme-linked immunosorbent (p < 0.05). However, when taking into account the levels of antibody positivity determined by enzyme-linked immunosorbent, the level of positive values according to chemiluminescent analysis was much higher than the performance of the manufacturer.