ANTIPHOSPHOLIPID ANTIBODY PROFILES IN CHINESE PATIENTS WITH SYSTEMIC LUPUS ERYTHEMATOSUS

Background: aPL antibodies are known to predispose to clinical thrombosis and pregnancy morbidities. Different prevalences have been reported by groups of different cultural background.Objectives: To examine the prevalence of aPL antibodies including lupus anticoagulant (LA), anti-cardiolipin (aCL) and anti-β2GPI (aβ2GPI) antibodies in our Chinese cohort of SLE and to examine their correlation with various clinical manifestations locally.Methods: Consecutive patients who satisfied the 1982 revised classification criteria for SLE were recruited. Patient records were reviewed for clinical thrombosis and pregnancy morbidity. LA was measured by phospholipid dependent assay, aCL and aβ2GPI antibodies were measured by ELISA. Only patients with results in the high positive range for the latter two antibodies were analysed further for clinical manifestations.Results: 201 consecutive SLE patients were recruited. Their mean ± SD age at the time of study was 38.3 ± 11.1 and they have been followed up for 10.6 ± 7.0 years. LA was found in 25.4% (51/201) of patients. IgG and IgM aCL antibodies in 31.8% (64/201) and 13.4% (27/201) respectively and IgG and IgM aβ2GPI antibodies in 16/201 (8.0%) and 23/201 (11.4%) respectively. Clinical vascular thrombosis was identified in 27/201 (13.4%) giving a thrombotic risk of 0.01%/patient-year. Recurrent risk in patients with history of thrombosis was 25.9% (7/27). Univariate analysis identified LA, IgG aCL and IgG aβ2GPI antibodies as risk factors for various presentations of clinical thrombosis. Multivariate analysis affirmed the role of LA in the development of clinical thrombosis [RR 3.3 CI 1.4-7.7, p<0.01] and stroke [RR 3.9 CI 1.1-13.3, p<0.05] and aβ2GPI antibodies in the development of venous thrombosis [RR 7.8 CI 2.0-30.1, p<0.005]. aβ2GPI antibodies were the only risk factor found to be strongly relate to recurrence of thrombosis [RR 25.4 CI 2.1-310.8, p=0.01] by multivariate analysis. There were only 24 female patients with > 1 pregnancy loss. Only IgG aβ2GPI antibodies were shown to be associated with > 1 unexplained fetal loss at or beyond the 10th gestational week with RR10.2 [CI 1.21-86.59] (p=0.03).Conclusion: The risk of thrombosis in our Chinese SLE cohort was found to be lower than our Caucasian counterparts. In consistent to other studies, aPL antibodies in Chinese cohort were also found to correlate well with clinical thrombosis in particular for LA and aβ2GPI antibodies. The low number of subjects with miscarriages did not give a big enough power to exclude a role of aPL antibodies in pregnancy morbidities in these patients.Citation: , volume , supplement , year 2003, page Session: SLE – Clinical aspects 1