Prevalence of Anti-Cardiolipin and Anti-β2 Glycoprotein Antibodies in Indian Systemic Lupus Erythematosus Patients

Anti-phospholipid antibodies (APA) like anti-cardiolipin antibodies (ACA) and anti-β2glycoprotien (anti-β2 GP) are important cause of venous and arterial thrombosis and other occlusive vascular diseases. The prevalence of these antibodies in SLE patients at the time of diagnosis is not known in Indian SLE patients. This study was conducted to evaluate the prevalence of ACA and anti-β2 GP autoantibodies in SLE patients and to correlate them with disease activity and immune parameters such as C3, C4 and CRP levels, where 85 SLE patients referred from Rheumatology Department, KEM hospital, Mumbai were studied. SLE disease activity was evaluated by SLE Disease Activity Index (SLEDAI) score at the time of evaluation. All patients studied were in an active stage of disease of which 37.6% patients had renal disorders, which were categorized as Lupus Nephritis (LN) and 62.3% patients did not show any renal manifestations (non-LN). ACA and anti-β2 GP autoantibodies, to IgG and IgM subclasses were tested by ELISA. C3, C4 and CRP levels were detected by nephelometer. It was observed that 12.9% patients were IgG-ACA and IgM-ACA positive and ACA positivity was noted more among LN group Anti-β2 GP autoantibody positivity was 27.1% for IgG and 31.8% for IgM., IgG-anti-β2 GP antibodies were slightly higher in non-LN patients, whereas a higher incidence of IgM-anti-β2 GP antibodies were detected in LN patients. Hence detection both ACA and anti-β2 GP antibodies along with associated immune parameters were helpful to evaluate their possible association with disease severity in SLE patients. A long term follow up of patients having ACA and anti-β2 GP antibodies without thrombotic event is also needed to detect their possible thrombotic event in future along with their clinical presentation.