Background:Currently, some data have been accumulated on the participation of antiphospholipid antibodies (aPL) in the development of thrombotic complications in patients with autoimmune rheumatic diseases (ARD), in particular, in patients with systemic lupus erythematosus (SLE). The most studied aPL in this pathology are IgG and IgM antibodies to cardiolipin (aCL), anti-β2-glycoprotein 1 antibodies (aβ2-GP 1), lupus anticoagulant (LA). The participation of IgG and IgM antibodies to prothrombin (aPT) and to annexin V (aAnV), antibodies to oxidized low density lipoproteins (aOxLDL) in hypercoagulation and the development of thrombosis is also discussed. However, the studies focusing on the investigation of aPL in patients with rheumatoid arthritis (RA) are few.Objectives:To estimate the levels and the frequency of occurrence of aPL in patients with RA in comparison to the SLE patients and the control group.Methods:The study included 85 female patients with ARD (RA (n=45), mean age 43,0 (33,0; 52,0) years old, disease duration 9,0 (5,0; 13,0) years, disease activity (DAS28= 5,37 (4,69; 5,89) points) and SLE (n=40), mean age 33,5 (27,5; 44,5) years old, disease duration 8,0 (5,0; 14,5) years, disease activity SLEDAI-2K 7,0 (4,0; 11,5) points). Fifty four healthy women (mean age 38,5 (35,0; 46,0) years old) formed the control group.The levels of antiphospholipid antibodies (IgG/IgM aCL, aβ2-GP 1, aAnV and aPT, aOxLDL) were determined with ELISA according to the instruction of a manufacturer. LA was determined by one-stage clotting assay using reagents for screening and confirmation (Technoclot LA Screen and Technoclot LA Confirm, Austria).Results:The frequency of occurrence of elevated levels of all investigated aPL in patients with RA was similar to SLE patients and was revealed in 57,8% of cases for IgG/IgM aCL, 44,4% for IgG/IgM aβ2-GP-1, 26,7% for IgG/IgM aAnV, 8,9% for aPT, 52,6% for LA, 64,4% for aOxLDL. The patients with SLE had an increased levels of IgG/IgM aCL in 60,0% of cases, IgG/IgM aβ2-GP-1 in 57,5%, IgG/IgM aAnV in 15,0%, IgG/IgM aPT in 17,5%, high levels of LA in 68,8%, of IgG aOxLDL – in 80,0% of cases. The control group had a high levels of IgG/IgM aCL in 1,8%, IgG/IgM aβ2-GP-1 in 3,7%, IgG/IgM aAnV in 5,6%, IgG/IgM aPT in 1,8%, high levels of IgG aOxLDL – in 42,6% of cases. None of the controls had an increased level of LA. The frequency of occurrence of elevated levels of aPL and their mean levels in both groups of patients with ARD was higher as compare to the control group (р<0,05).The mean levels of IgG aβ2-GP-1, LA, aOxLDL in SLE patients and mean levels of LA, aOxLDL in RA patients were above standard values but were similar in both groups. Moreover, the mean levels of IgG aCL, IgM aβ2-GP-1, IgG/IgM aAnV and aPT were comparable in patients with SLE and RA. However, the mean levels of IgM aCL in RA patients was higher than in SLE patients. This may indicate an increased autoimmune activity.Simultaneous elevation in four types of aPL levels was observed in 4,4% patients with RA, in 2,5% - with SLE; simultaneous elevation in three types of aPL was reveled in 11,1% patients with RA, in 17,5% - with SLE; two types of aPL were increased in 35,6% patients with RA and 27,5% - with SLE. Only one type of elevated aPL levels (12,9%) was indentified in the control group.Conclusion:Thus, patients with RA are characterized by a wide range of aPL. Qualitative and quantitative changes in the levels and types of autoantibodies in patients with RA have been established similar to those in SLE patients.In patients with autoimmune rheumatic pathology, the presence of simultaneously elevated several types of aPL have been proved.Disclosure of Interests:None declared
Occurrence of nucleic acid hydrolyzing IgM antibodies in rheumatoid arthritis patients’ sera
