AB0434 Antibody to dsdna (anti-dsdna), circulating immune complex (cic) in systemic lupus erithematosus (sle) and antiphospholipid syndrome (aps)

Background The presence both of antiphospholipid antibodies (aPL) and anti-dsDNA is immunological features of diagnostic criteria of SLE. The level of anti-dsDNA usually reflects renal involvement of SLE and antiphospholipid antibodies (aPL) is associated with thrombotic events. Cross-reaction between these antibodies is discussed. Objectives To assess the frequency of anti-dsDNA, increasing of CIC, hypocomplementemie in SLE and APS (in primary and secondary) and their connection with anticardiolipin antibodies (aCL) and clinical manifestations of the disease. Methods We studied 365 patients in mean age 31,9±10,9 years (from 14 to 63yrs.) and disease duration 9,1±7,5years (from6 month to 36 yrs). SLE was diagnosed in 135 (56M, 79F) patients (ACR criteria, 1997) and 230 (55M, 175F) patients had APS. Secondary APS (SLE+APS) was in 156 of 230 patients and primary – in 74. Anti-dsDNA and aCL were measured by ELISA. CH50 was evaluated by 50% hemolytic activity. C3, C4 were determined by immunonephelometric assay, CIC – by turbidimetric assay with 3,5% PEG. Results High level of anti-dsDNA was found to have 80% of SLE patients (mean level 68,5±28,6 OD from 30 to 120) and it was associated with glomerulonephritis and hipocomplementemia. Increased levels of IgG-aCL were detected in 22% of SLE patients and IgM-aCL - in17%, but nobody of them had any APS features. There was correlation between IgG-aCL and anti-dsDNA, CIC and IgG. High level of anti-dsDNA was found in 75% of SLE+APS patients and it was correlated with activity disease estimating by SLEDAI score (35.2±14.2 vs 12.3±5.7) but not with renal involvement. Fifty six percent of 156 SLE+APS patients were IgG-aCL positive and 28% - IgM-aCL positive. Thrombosis were revealed in 48% of IgG-aCL positive SLE+APS patients and thrombocytopenia in 15% of IgM-aCL positive patients. Immunological abnormalities have revealed in 25% of 74 PAPS patients: 25% had false positive test for siphylis, 61% - high level of CIC, 7% -anti-DNA and 19% - hipocomplementemia. High level of anti-dsDNA in PAPS patients was associated with microvascular complication: digital necrosis and Rayunad’s phenomen. There was correlation between IgG-aCL and CIC in APS patients. Conclusions High level of anti-dsDNA in SLE patients associated with renal damage. There was correlation between the levels of anti-dsDNA with SLEDAI score in SLE+APS patients and wasn’t associated with renal involvement. Immunological abnormalities (CIC, low C3, C4) except aCL-positivity have revealed in PAPS patients. Disclosure of Interest None Declared