AB0434 The Role of IGG Anti [beta]2-GPI in The Clinical Manifestations of Systemic Lupus Erythematosus

Background Beta 2 GPI is an important antigenic target for antiphospholipid antibodies. The role of IgG antibodies to β2 glycoprotein I [Anti-β2-GPI] has been well defined in antiphospholipid antibody syndrome but its role in the clinical manifestions of SLE remains elusive. Objectives To investigate the role of Anti-β2-GPI in the clinical manifestations of SLE Methods IgG Anti-β2-GPI was measured in 184 patients with SLE (93% women, mean age 28 years). IgG Anti-β2-GPI (>18 GPL units) was found in 19 patients (10.3%). Associations were determined with clinical manifestations of SLE and with components of the Systemic Lupus International Collaborating Clinics/American College of Rheumatology (SLICC/ACR) Damage Index Results Of the patients with SLE who demonstrated IgG Anti-β2-GPI, 31% had at least one thrombotic event (OR 4.2, p=0.01), 26% had pulmonary hypertension (OR 3.2, p=0.02) and 26% had recurrent abortions (OR 4.1, p=0.02). IgG Anti-β2-GPI was protective against lupus nephritis (OR 0.31, p=0.02). No other manifestations were significantly higher in patients with IgG Anti-β2-GPI positivity Clinical Manifestation Anti-β (2)-GPI --- Positive Negative --- Recurrent abortions Present 5 13 OR 4.1 p=0.02 Absent 14 152 Thrombotic events Present 6 16 OR 4.2 p=0.01 Absent 13 149 Pulmonary hypertension Present 5 15 OR 3.2 p=0.02 Absent 14 150 Lupus nephritis Present 6 98 OR 0.31 p=0.02 Absent 13 67 Conclusions In SLE, IgG Anti-β2-GPI is associated with thrombotic events and pulmonary hypertension, but may have a protective effect against lupus nephritis. Large scale studies are required to confirm these findings. References Vikerfors A, Johansson AB, Gustafsson JT, Jönsen A, Leonard D, Zickert A et al. Clinical manifestations and anti-phospholipid antibodies in 712 patients with systemic lupus erythematosus: evaluation of two diagnostic assays. Rheumatology (Oxford). 2013 Mar;52(3):501-9. Meroni PL, Raschi E, Grossi C, Pregnolato F, Trespidi L, Acaia B et al. Obstetric and vascular APS: same autoantibodies but different diseases? Lupus. 2012 Jun;21(7):708-10. Matsuura E, Shen L, Matsunami Y, Quan N, Makarova M, Geske FJ et al. Pathophysiology of beta2-glycoprotein I in antiphospholipid syndrome. Lupus. 2010 Apr;19(4):379-84. Disclosure of Interest None declared