Fig. 1

Levels of anti-β2GPI/HLA-DR antibodies in all participants with primary diseases. Abbreviations: AAV, ANCA-associated vasculitis; aGAPSS, adjusted global APS score; aCL, anticardiolipin antibody; aβ2GPI, anti-β2GPI antibody; aPL, antiphospholipid antibody; APS, antiphospholipid antibody syndrome; BD, Bechet disease; IIMs, idiopathic inflammatory myopathies; LA, lupus anticoagulant; LVV, large-vessel vasculitis; pAPS, primary antiphospholipid antibody syndrome; RA, rheumatoid arthritis; SjS, Sjögren’s syndrome; SLE, systemic lupus erythematosus; SSc, systemic sclerosis. A Anti-β2GPI/HLA-DR antibodies were quantified in patients with various primary systemic rheumatic diseases. B Anti-β2GPI/HLA-DR antibody titers (in U/mL) from each primary disease. The dashed line indicates the cut-off value of 172.359 U/mL, resulting from Fig. 3. A cut-off value of 73.3 U/mL has been reported when comparing APS to healthy participants. C Anti-β2GPI/HLA-DR antibody titers among different APS subsets (carrier/primary/secondary). D Anti-β2GPI/HLA-DR antibody titers were significantly higher in patients with both arterial and venous thrombosis than in those with no or venous-only thrombosis. E Among different aPL subsets (none/single/double/triple-positive), anti-β2GPI/HLA-DR antibody titers increased with the order of increasing aPL positivity. F Anti-β2GPI/HLA-DR antibody titers increased with increasing order of aGAPSS clusters: none (< 1 point), very low (1–3 points), low (4–5 points), middle (6–9 points), high (10–13 points), and very high (≥ 14 points)