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

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.

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Disclosure of Interest None declared